NSF Thread 4

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General Discussion => Advanced Concepts => Topic started by: Rodal on 08/07/2015 06:19 PM

Title: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/07/2015 06:19 PM
This is a thread - Thread 4 in the series - focused on objective analysis of whether the EM Drive (a cavity resonating at microwave frequencies) reported "thrust force" is an experimental artifact or whether it is a real propulsion effect  that can be used for space applications, and if so, in discussing those possible space propulsion applications.

Objective skeptical inquiry is strongly welcome.   Disagreements should be expressed politely, concentrating on the technical, engineering and scientific aspects, instead of focusing on people.   As such, the use of experimental data, mathematics, physics, engineering, drawings, spreadsheets and computer simulations are strongly encouraged, while subjective wordy statements are discouraged. Peer-reviewed information from reputable journals is strongly encouraged.  Please acknowledge the authors and respect copyrights.


Commercial advertisement is discouraged.


In order to minimize bandwidth and  maximize information content, when quoting, one can use an ellipsis (...) to indicate the clipped material.

Only use the embed [img ]http://code when the image is small enough to fit within the page. Anything wider than the width of the page makes the page unreadable as it stretches it (we're working on auto reduction, but different browsers work different ways, etc.)

This link

http://math.typeit.org/

enables typing of mathematical symbols, including differentiation and integration, Greek letters, etc.

--

Links to previous threads:

Thread 1:
http://forum.nasaspaceflight.com/index.php?topic=29276.0

Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=36313.0

Thread 3:
http://forum.nasaspaceflight.com/index.php?topic=37642.0

--

Entry level thread:
http://forum.nasaspaceflight.com/index.php?topic=37438.0

Baseline NSF Article:
http://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-em-drive/



This is the link to the EM Drive wiki that users are encouraged to contribute to, edit for accuracy, and build as a knowledge resource for the EM Drive:

http://emdrive.wiki




Chris note: Please note all posts need to be useful and worthwhile or they will be removed via moderation. This subject has large interest, with over 2.5 million thread reads and 750,000 article reads. Most people are reading and not posting, so when you post it is in front of a very large audience.

Also, and it should go without saying, amateur experiments are discouraged unless you have gained educated and/or professional advice for safety reasons.

(be-careful-safety-first-sign-s-4115.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/07/2015 06:43 PM
Ok, I made some additions, modifications and improvements to my .xls spreadsheet (see attached).

I've created an alternate version of McCulloch's 3D equation because, why not.  I substituted area for diameter and that allowed me to drop that 6 off the front.  The McCulloch 3D Modified equation is (I know it's messy):

((P*Q*L)/c)*((1/L+Pi*Br^2)-(1/L+Pi*Sr^2))

P = Power in Watts
Q = Q
L = Length
c = Speed of Light
Br = Radius of the Large End
Sr = Radius of the Small End
Pi = π

Anyway, the above modifications just felt more natural than McCulloch's original 3D derivation and it brought the Tajmar prediction back into line.

One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.  It works with Shawyer and with Juan.  The predictions hold up with the Cannae drive for some reason, but fall flat on their face with the NASA tested Brady drive.  Once again, all specifications have been stolen from McCulloch's blog (with the exceptions of my daydream, rfmwguy and TheTraveller).

My predicted thrust for rfmwguy's build works out to 226.00mN! 

McCulloch's unedited 3D equation (assuming I entered it into the spreadsheet correctly) works out a prediction of 157.70mN!

Can't wait!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: JasonAW3 on 08/07/2015 06:43 PM
I have a thought for anyone doing this experiment, both in the open air and in a vacume chamber.

     I would be interested in seeing what the total mass of the complete experiment rig is before and during the actual experiment.  I fully expect there to be some "noise" in the measurement, but I think a short series of these experiments should be able to average out the real mass measurements.  I have a couple of theories as to what might be going on, depending on what the actual mass readings are compared to before and during the experiment.

      I don't want to really go into the theories as it may affect the results.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/07/2015 06:49 PM
Thinking about the ongoing controversy regarding TheTraveller's and Shawyer's theory raises a question for me.  Please forgive if this has been addressed in one of the earlier threads.

If Shawyer's theory is wrong then is Cullen's eqn 15 also incorrect??  Eqn 15 seems to be the bedrock of the theory (the bible they punch :D).

I am trying to unpack the controversy a bit from the recent standard of "the physics/theory is wrong".

Edit: Clarification.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/07/2015 07:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.
Because, as we've tried to explain countless times, the Qs in Yang/Shell were grossly overstated. I think Thor is generous when he only divides it by 10.

Want proof? Look at Tajmar's Q, then look at yang/shawyers and tell me why there is a so much disparity. The disparity lies in yang/shawyers unfamiliarity with cavity Q measurement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/07/2015 07:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.

Obviously Q isn't Q if everybody's measuring it differently and getting different values.

But mostly, I noticed a trend and thought it was interesting.  There was so much controversy swirling around with the whole "how do you calculate Q" thing, and since Q is an integral part of the McCulloch equation I thought I'd play around with it a bit.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/07/2015 07:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414192#msg1414192">Quote from: tleach on 08/07/2015 07:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.

Obviously Q isn't Q if everybody's measuring it differently and getting different values.

But mostly, I noticed a trend and thought it was interesting.  There was so much controversy swirling around with the whole "how do you calculate Q" thing, and since Q is an integral part of the McCulloch equation I thought I'd play around with it a bit.
About the only way to resolve this Thor, is to do what you did, adjust reported Q to achieve the reported thrust, given the other parameters remain constant. Once you have static formulae, use Q as the variable to equate reported thrust. Nicely done...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/07/2015 07:19 PM
I am sure many people know the Smith program. For all other here are the links.
Note the Icon/subprogram "circles".
Circles for Q, SWR and more are addable.
( Be careful while interpretating:  Q of the cavity it selves for example is one thing the coupling factor of the antenna another, both are important!)
It's a very helpful program for the toolbox and RF engineering. :)

http://www.fritz.dellsperger.net/smith.html
http://fritz.dellsperger.net/downloads/Help%20V3.10.pdf

My wine don't like it at the moment  >:( :-\ for windows it works fine
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414192#msg1414192">Quote from: tleach on 08/07/2015 07:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.

Obviously Q isn't Q if everybody's measuring it differently and getting different values.

But mostly, I noticed a trend and thought it was interesting.  There was so much controversy swirling around with the whole "how do you calculate Q" thing, and since Q is an integral part of the McCulloch equation I thought I'd play around with it a bit.

In the experimental EMDrive world of Shawyer, Prof Yang, Eagleworks and Tajmar, unloaded Q is measured and reported as the 3dB down bandwidth from the max return loss dB divided into the resonant frequency.

As Tajmar reported in the attachment.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/07/2015 07:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.

And beside, when you use your spreadsheet from May and plug in a Df of .0844 and a Q of 45,000 you know what the mN of thrust predicted is?  It's 253.4 mN.  You know what my prediction is with the adjusted Q?  It's 251.24 mN (and I used 3.14 for Pi).  I'd say that's pretty darn close, wouldn't you?  And with observed results as high as 214, I'd say we're both in the same ballpark.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414191#msg1414191">Quote from: rfmwguy on 08/07/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.
Because, as we've tried to explain countless times, the Qs in Yang/Shell were grossly overstated. I think Thor is generous when he only divides it by 10.

Want proof? Look at Tajmar's Q, then look at yang/shawyers and tell me why there is a so much disparity. The disparity lies in yang/shawyers unfamiliarity with cavity Q measurement.

They all measure their unloaded Q the same way.

Measured resonant frequency at max return loss dB / bandwidth at 3dB down from the peak return loss dBs.

Examples from Eagleworks, Tajmar and Prof Yang. All using the same method to calc unloaded Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/07/2015 07:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414196#msg1414196">Quote from: TheTraveller on 08/07/2015 07:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414192#msg1414192">Quote from: tleach on 08/07/2015 07:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414186#msg1414186">Quote from: TheTraveller on 08/07/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414180#msg1414180">Quote from: tleach on 08/07/2015 06:43 PM</a>
One other interesting thing I found was that many of the extremely large Q frustums can be brought back into line with predicted values by simply dividing the provided Q value by 10.

Why would you do that?

The Demonstrator EMDrive has a stated Q of 45,000 and Df of 0.844.

The data is what it is.

Obviously Q isn't Q if everybody's measuring it differently and getting different values.

But mostly, I noticed a trend and thought it was interesting.  There was so much controversy swirling around with the whole "how do you calculate Q" thing, and since Q is an integral part of the McCulloch equation I thought I'd play around with it a bit.

In the experimental EMDrive world of Shawyer, Prof Yang, Eagleworks and Tajmar, unloaded Q is measured and reported as the 3dB down bandwidth from the max return loss dB divided into the resonant frequency.

As Tajmar reported in the attachment.
I will take the time to explain this one more time, Mr T. after that, either you are deliberately trying to confuse the issue or you simply cannot comprehend.

Q = Ctr freq of resonance/3dB bandwidth (total half power bandwidth). Return loss has no bearing on a Q measurement, it MUST be a 2 port measurement, otherwise it is a single-port device akin to an antenna, not a cavity. The calculations used in virtually all relative RF and Microwave circuits calculate Q in the same way, not what yang/shawyer invented.

http://docs.lumerical.com/en/diffractive_optics_cavity_q_calculation.html

"High Q cavities

Derivation of Q factor formula:

The quality factor (Q) is defined as (see image) where wr is the resonant frequency ( ωr=2π fR) and FWHM is the full width half max of the resonance intensity spectrum."

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/07/2015 07:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414202#msg1414202">Quote from: TheTraveller on 08/07/2015 07:31 PM</a>
They all measure their unloaded Q the same way.

Measured resonant frequency at max return loss dB / bandwidth at 3dB down from the peak return loss dBs.

Examples from Eagleworks, Tajmar and Prof Yang. All using the same method to calc unloaded Q.

You are absolutely, 100% right.  I hereby defer to you in all future disagreements.  I apologize for my impertinence.  My spreadsheet is wrong and your spreadsheet is right.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414205#msg1414205">Quote from: rfmwguy on 08/07/2015 07:34 PM</a>
I will take the time to explain this one more time, Mr T. after that, either you are deliberately trying to confuse the issue or you simply cannot comprehend.

Q = Ctr freq of resonance/3dB bandwidth (total half power bandwidth). Return loss has no bearing on a Q measurement, it MUST be a 2 port measurement, otherwise it is a single-port device akin to an antenna, not a cavity. The calculations used in virtually all relative RF and Microwave circuits calculate Q in the same way, not what yang/shawyer invented.

http://docs.lumerical.com/en/diffractive_optics_cavity_q_calculation.html

"High Q cavities

Derivation of Q factor formula:

The quality factor (Q) is defined as (see image) where wr is the resonant frequency ( ωr=2π fR) and FWHM is the full width half max of the resonance intensity spectrum."

That may be how you would do it but it is not how Shawyer, Prof Yang, Eagleworks and Prof Tajmar measure their frustums unloaded Q as I just showed you.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414208#msg1414208">Quote from: tleach on 08/07/2015 07:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414202#msg1414202">Quote from: TheTraveller on 08/07/2015 07:31 PM</a>
They all measure their unloaded Q the same way.

Measured resonant frequency at max return loss dB / bandwidth at 3dB down from the peak return loss dBs.

Examples from Eagleworks, Tajmar and Prof Yang. All using the same method to calc unloaded Q.

You are absolutely, 100% right.  I hereby defer to you in all future disagreements.  I apologize for my impertinence.  My spreadsheet is wrong and your spreadsheet is right.

It has nothing to do with me nor my spreadsheet.

I just showed you how Prof Yang, Eagleworks and Prof Tajmar measured their frustums unloaded Q. Note Prof Tajmar used an expert professor in uW engineering to measure his frustums unloaded Q by using the same 1 port S11 return loss method as used by Shawyer, Prof Yang and Eagleworks.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sghill on 08/07/2015 07:46 PM
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414205#msg1414205">Quote from: rfmwguy on 08/07/2015 07:34 PM</a>
The calculations used in virtually all relative RF and Microwave circuits calculate Q in the same way, not what yang/shawyer invented.

An EMDrive cavity is not a standard cavity.

As I have shown you before, it is industry standard practice, maybe not yours, to use 1 port S11 return loss to measure unloaded cavity Q. You may disagree with the information on the slide but it is incorrect to say Shawyer and Prof Yang invented this method to measure unloaded Q.

As the slide clearly shows, to some it is the way to do the measurement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

In the EMDrive world measuring unloaded Q via S11 return loss at the 3bd down bandwidth is how it is measured.

So say Shawyer, Prof Yang, Eagleworks and Prof Tajmar.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/07/2015 07:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

As far as I can gather, @TT is saying, "How they did it". @rfmwguy is saying "How it should've been done." and @tleach is saying "This is how it seems to fit McCulloch's formula."

Which BTW, McCulloch doesn't define how to measure Q. He simply redefines it as the number of bounces (reflections), in the time it takes the photon to decay to zero. So that's not even the same definition of the Q that is being kicked around here. @tleach was trying to bridge that gap.

What I conclude is, the experimenters may or may not be measuring it consistently using the same methodology, but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/07/2015 07:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd

So Dr. Ray Kwok is also wrong?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/07/2015 08:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

As far as I can gather, @TT is saying, "How they did it". @rfmwguy is saying "How it should've been done." and @tleach is saying "This is how it seems to fit McCulloch's formula."

Which BTW, McCulloch doesn't define how to measure Q. He simply redefines it as the number of bounces (reflections), in the time it takes the photon to decay to zero. So that's not even the same definition of the Q that is being kicked around here. @tleach was trying to bridge that gap.

What I conclude is, the experimenters may or may not be measuring it consistently using the same methodology, but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd

Thank you for summarizing the case, clarifying the problem and providing a conclusion.  Well done. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/07/2015 08:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414218#msg1414218">Quote from: TheTraveller on 08/07/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

In the EMDrive world measuring unloaded Q via S11 return loss at the 3bd down bandwidth is how it is measured.

So say Shawyer, Prof Yang, Eagleworks and Prof Tajmar.

I have to agree at this point, BUT for that you MUST know the coupling factor between your generator-antenna-cavity, only for the coupling factor K=1 the full 3dB BW is usable. 

 
PDF: copy and past for translation somewhere ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/07/2015 08:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

As far as I can gather, @TT is saying, "How they did it". @rfmwguy is saying "How it should've been done." and @tleach is saying "This is how it seems to fit McCulloch's formula."

Which BTW, McCulloch doesn't define how to measure Q. He simply redefines it as the number of bounces (reflections), in the time it takes the photon to decay to zero. So that's not even the same definition of the Q that is being kicked around here. @tleach was trying to bridge that gap.

What I conclude is, the experimenters may or may not be measuring it consistently using the same methodology, but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd
It would be oh-so-simple to resolve this. Send a closed, resonant cavity to NIST, the British Standards Institute (BSI) or other reputable body with ONLY 1 PORT and have them measure Q. After they ask where the other port is, they would ask, why would you want to measure a closed cavity system with only one port? IOW, an open system, like an antenna, only needs a single port. A resonant cavity needs 2 to properly measure Q.

I'll stand by this (un)controversial position regardless of the previous experimenters. Quite frankly, I'm surprised at their apparent lack of RF familiarity. This is not a slam, it is a known fact that RF engineering is taught less, practiced less and is receeding into the background of companies and institutions. Reason? Computer science boom and the "plug and play & throw away" mentality of electronics in general.

Open system = 1 port
Closed system (frustum) = 2 port

Case closed. Its the last I will post on this matter at NSF.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/07/2015 08:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414229#msg1414229">Quote from: rfmwguy on 08/07/2015 08:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

As far as I can gather, @TT is saying, "How they did it". @rfmwguy is saying "How it should've been done." and @tleach is saying "This is how it seems to fit McCulloch's formula."

Which BTW, McCulloch doesn't define how to measure Q. He simply redefines it as the number of bounces (reflections), in the time it takes the photon to decay to zero. So that's not even the same definition of the Q that is being kicked around here. @tleach was trying to bridge that gap.

What I conclude is, the experimenters may or may not be measuring it consistently using the same methodology, but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd
It would be oh-so-simple to resolve this. Send a closed, resonant cavity to NIST, the British Standards Institute (BSI) or other reputable body with ONLY 1 PORT and have them measure Q. After they ask where the other port is, they would ask, why would you want to measure a closed cavity system with only one port? IOW, an open system, like an antenna, only needs a single port. A resonant cavity needs 2 to properly measure Q.

I'll stand by this (un)controversial position regardless of the previous experimenters. Quite frankly, I'm surprised at their apparent lack of RF familiarity. This is not a slam, it is a known fact that RF engineering is taught less, practiced less and is receeding into the background of companies and institutions. Reason? Computer science boom and the "plug and play & throw away" mentality of electronics in general.

Open system = 1 port
Closed system (frustum) = 2 port

Case closed. Its the last I will post on this matter at NSF.
 ???
It may be much more easy to measure with a calibrated(!) 2 port system...
But one can derive the S-parameter based on a 1 port measurement!
In doubt use a circulator and a load..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/07/2015 08:39 PM
I think the reason why all the EmDrive experimenters to date (Shawyer, Yang, Brady/White, Tajmar) measured the unloaded Q (or Qu) as the S11 1 port return loss (resonant frequency at maximum return loss dB -3dB off this peak return loss dB value) is not because they would not know or don't want to use the more official S22 2-port method, but because the Qu they get from the S11 1-port method is a suitable value that can be plugged readily into their equations to calculate and predict theoretical thrust. Obviously the S22 2-port method does not provide a value for Q usable to calculate thrust, at least according to their equations.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/07/2015 08:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414247#msg1414247">Quote from: flux_capacitor on 08/07/2015 08:39 PM</a>
I think the reason why all the EmDrive experimenters to date (Shawyer, Yang, Brady/White, Tajmar) measured the unloaded Q (or Qu) as the S11 1 port return loss (resonant frequency at maximum return loss dB -3dB off this peak return loss dB value) is not because they would not know or don't want to use the more official S22 2-port method, but because the Qu they get from the S11 1-port method is just a suitable value that can be plugged readily into their equations to calculate and predict theoretical thrust. Obviously the S22 2-port value does not provide a value usable to calculate thrust, at least according to their equations.
transmission measurement is S12 or S21

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/07/2015 08:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414248#msg1414248">Quote from: X_RaY on 08/07/2015 08:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414247#msg1414247">Quote from: flux_capacitor on 08/07/2015 08:39 PM</a>
I think the reason why all the EmDrive experimenters to date (Shawyer, Yang, Brady/White, Tajmar) measured the unloaded Q (or Qu) as the S11 1 port return loss (resonant frequency at maximum return loss dB -3dB off this peak return loss dB value) is not because they would not know or don't want to use the more official S22 2-port method, but because the Qu they get from the S11 1-port method is just a suitable value that can be plugged readily into their equations to calculate and predict theoretical thrust. Obviously the S22 2-port value does not provide a value usable to calculate thrust, at least according to their equations.
transmission measurement is S12 or S21

Ok thanks but you know what I meant ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/07/2015 08:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414221#msg1414221">Quote from: TheTraveller on 08/07/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd

So Dr. Ray Kwok is also wrong?

I see nothing incorrect about what Dr. Kwok said. He said "Resonators". An antenna is a resonator and so is a cavity. One is an open system, the other is a closed system. The preferred methods are different at a "National Standards" level, according to @rfmwguy. While I agree 100% that the experimenters to date have consistently used the S11 method, that does not mean it is the "standard" way to do it. You are arguing that "In the EM Drive world" this is how it's done. Perhaps this is true, but is no less true that this is NOT the "standard" way to do it.

Stop arguing about it and accept that fact please. You're driving everyone bonkers with your obstinance and defense of obvious incongruences. I do not follow others. I make mistakes, try to understand learn from them and forge my own path and from what I've seen, that is how most of us here operate.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/07/2015 09:06 PM
I'll provide as much clear clean precise data as I can from my tests. That is my goal. There is no bad Data.

What theorists and non-theorists do with it by massaging it, reformulating it, how they plug it into those theories is beyond my control, but the Data rules here in this level of the EMDrive's development.

Back to //lurking//

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/07/2015 09:10 PM
Just a question regarding the Q measurement :
Even if we know that the Q's are/were measured in the wrong way, wouldn't it be wise to continue with the faulty system, in order to make all those test comparative?

If measurement standards are changed now to the correct method, all the data we have up till now becomes inaccurate or no longer useable, no?
One can question the validity of the previous information bits that have been gathered, but this sure will not help... throw it all overboard then? ???
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/07/2015 09:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414262#msg1414262">Quote from: Flyby on 08/07/2015 09:10 PM</a>
Just a question regarding the Q measurement :
Even if we know that the Q's are/were measured in the wrong way, wouldn't it be wise to continue with the faulty system, in order to make all those test comparative?

If measurement standards are changed now to the correct method, all the data we have up till now becomes inaccurate or no longer useable, no?
One can question the validity of the previous information bits that have been gathered, but this sure will not help... throw it all overboard then? ???
Does everyone knows about the inner impedance of a oven magnetron?
If it is still ~50 Ohm there is no problem, the antenna coupling is as good in as out. 2 port measurement is equal to second port out at 50 Ohm...
In the 2 port case you have 2 times 50 Ohm(simple case) of out coupling means
1/50+1/50=25 Ohm
 Thats the difference, nothing else (with respect to the coupling factor of each single antenna).
1/Q_eff=1/Q_int+1/Q_ext
If Q_ext(ernal) is known, whats the problem to derive Q_int(ernal) based on the measurement data  ???
S-parameter (of a calibrated system) at each antenna(impedance) is all you need to derive the unloaded Q.  It does'nt matter if 1 or 2 antennas will be used.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/07/2015 09:25 PM
All this discussion about Q is relevant if the expression of the force on total system ( cavity +microwave source) is correct.
Any closed cavity can suffer of a  non null net force produced by a electromagnetic field inside it acting on its HOLE INTERNAL SURFACE, but the source of the EM field is under force too, and MUST be accounted too.
No expression until now, shows the force calculated on entire surface, or take the source of the EM fields into account simultaneously.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/07/2015 09:50 PM
Q = f / deltaF
where deltaF is the frequency spread between lower and upper -3 dB points.
I think the differences discussed stem from how that -3 dB is measured, no?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfcavity on 08/07/2015 09:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414277#msg1414277">Quote from: deltaMass on 08/07/2015 09:50 PM</a>
Q = f / deltaF
where deltaF is the frequency spread between lower and upper -3 dB points.
I think the differences discussed stem from how that -3 dB is measured, no?

If this is true then Q should not be used for any kind of thrust estimation or calculation. This kind of Q-factor is a human construct to facilitate easy discussion about simplified performance of RF/microwave things, with some sort of consensus of how to measure it reached 60 years ago (more or less, as demonstrated by this thread). It is essentially distilling the whole spectrum measurement into 3 points. It's very difficult to believe that this would produce better thrust estimation than utilizing the full integrated frequency spectrum of stored energy within the cavity.

In short, Q in this case is just an aspect of a design that should be used to make high level engineering decisions about multiple designs. It should not be used as a direct input to try and find quantitative values of physical phenomena.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/07/2015 10:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414277#msg1414277">Quote from: deltaMass on 08/07/2015 09:50 PM</a>
Q = f / deltaF
where deltaF is the frequency spread between lower and upper -3 dB points.
I think the differences discussed stem from how that -3 dB is measured, no?
For a 1 port measurement may be.
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414228#msg1414228

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/07/2015 10:37 PM

@rfmwguy

"Thermal tests done including 5 minute run at 30% power, which is what I'll use for fulcrum test."  So you're actually putting in 30% of 900W which would be approximately 270W.

And then there's the conversion of electrical energy into microwave energy. If we assume that wikepedia is correct, a 900W microwave oven magnetron should run with approximately 64% efficiency. 

https://en.wikipedia.org/wiki/Microwave_oven#Heating_efficiency

That means you're magnetron is only putting 172.8W of energy into your frustum.  I'm officially revising my force prediction (based on my v3 spreadsheet and a projected S12 Q factor of 7000) down 43.41 mN. 

Sorry :-)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/07/2015 10:41 PM
Not coming from the RF world, I wonder why this whole discussion about Q can't settle on Q=2*π*energy_stored/energy_dissipated_per_cycle as a standard. Out of curiosity, isn't it possible to switch off a RF source fast enough (a few cycles) and get this Q value by observing only the time constant of the decay of amplitude with a minimally invasive probe ?

BTW, not wanting to sound insistent but there is no answer to my questions about the relation of Q and "losses per round trip" (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1414001#msg1414001) (in the context of a linear resonant set up). If I am making a mistake by thinking "number of bounces" when hearing Q, then I'm not the only one : Think of it like the number of times a photon bounces inside a mirrored cavity. (https://www.reddit.com/r/EmDrive/comments/3fz91k/in_an_emdrive_q_rules/cttks09) A clarification might be useful.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/07/2015 11:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414285#msg1414285">Quote from: frobnicat on 08/07/2015 10:41 PM</a>
Not coming from the RF world, I wonder why this whole discussion about Q can't settle on Q=2*π*energy_stored/energy_dissipated_per_cycle as a standard. Out of curiosity, isn't it possible to switch off a RF source fast enough (a few cycles) and get this Q value by observing only the time constant of the decay of amplitude with a minimally invasive probe ?

BTW, not wanting to sound insistent but there is no answer to my questions about the relation of Q and "losses per round trip" (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1414001#msg1414001) (in the context of a linear resonant set up). If I am making a mistake by thinking "number of bounces" when hearing Q, then I'm not the only one : Think of it like the number of times a photon bounces inside a mirrored cavity. (https://www.reddit.com/r/EmDrive/comments/3fz91k/in_an_emdrive_q_rules/cttks09) A clarification might be useful.

My conjecture on this would be that, a small cone angle will cause more bounces and a higher Q. However, my feeling is that as the wave propagates from the small end to the big end, it is reflecting off the side walls. Each reflection off the side walls imparts a tiny bit of momentum to the frustum. So the more bounces off the side walls (not the end plates) will produce more thrust. This means that a slower group velocity, bouncing over a longer period of time, would give higher thrust. This leads to the idea that the frustum should be shaped more like a trombone with a long throat. But... none of the theories so far support this idea, but none have tried either.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 12:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414295#msg1414295">Quote from: WarpTech on 08/07/2015 11:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414285#msg1414285">Quote from: frobnicat on 08/07/2015 10:41 PM</a>
Not coming from the RF world, I wonder why this whole discussion about Q can't settle on Q=2*π*energy_stored/energy_dissipated_per_cycle as a standard. Out of curiosity, isn't it possible to switch off a RF source fast enough (a few cycles) and get this Q value by observing only the time constant of the decay of amplitude with a minimally invasive probe ?

BTW, not wanting to sound insistent but there is no answer to my questions about the relation of Q and "losses per round trip" (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1414001#msg1414001) (in the context of a linear resonant set up). If I am making a mistake by thinking "number of bounces" when hearing Q, then I'm not the only one : Think of it like the number of times a photon bounces inside a mirrored cavity. (https://www.reddit.com/r/EmDrive/comments/3fz91k/in_an_emdrive_q_rules/cttks09) A clarification might be useful.

My conjecture on this would be that, a small cone angle will cause more bounces and a higher Q. However, my feeling is that as the wave propagates from the small end to the big end, it is reflecting off the side walls. Each reflection off the side walls imparts a tiny bit of momentum to the frustum. So the more bounces off the side walls (not the end plates) will produce more thrust. This means that a slower group velocity, bouncing over a longer period of time, would give higher thrust. This leads to the idea that the frustum should be shaped more like a trombone with a long throat. But... none of the theories so far support this idea, but none have tried either.
Todd
Todd, but the axial force component due to the side walls equals Sin[theta]*SideWallForce, where theta is the cone half-angle.  For theta = 0 ( a cylinder) the axial component due to the SideWallForce is Sin[0]*SideWallForce=0, it is zero no matter how large is the SideWallForce.  For small theta, the SideWallForce axial component is very low.  So, even if one grants you that the SideWallForce may be larger for small cone angle, the axial component is small.  Comments?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 12:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414299#msg1414299">Quote from: Rodal on 08/08/2015 12:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414295#msg1414295">Quote from: WarpTech on 08/07/2015 11:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414285#msg1414285">Quote from: frobnicat on 08/07/2015 10:41 PM</a>
Not coming from the RF world, I wonder why this whole discussion about Q can't settle on Q=2*π*energy_stored/energy_dissipated_per_cycle as a standard. Out of curiosity, isn't it possible to switch off a RF source fast enough (a few cycles) and get this Q value by observing only the time constant of the decay of amplitude with a minimally invasive probe ?

BTW, not wanting to sound insistent but there is no answer to my questions about the relation of Q and "losses per round trip" (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1414001#msg1414001) (in the context of a linear resonant set up). If I am making a mistake by thinking "number of bounces" when hearing Q, then I'm not the only one : Think of it like the number of times a photon bounces inside a mirrored cavity. (https://www.reddit.com/r/EmDrive/comments/3fz91k/in_an_emdrive_q_rules/cttks09) A clarification might be useful.

My conjecture on this would be that, a small cone angle will cause more bounces and a higher Q. However, my feeling is that as the wave propagates from the small end to the big end, it is reflecting off the side walls. Each reflection off the side walls imparts a tiny bit of momentum to the frustum. So the more bounces off the side walls (not the end plates) will produce more thrust. This means that a slower group velocity, bouncing over a longer period of time, would give higher thrust. This leads to the idea that the frustum should be shaped more like a trombone with a long throat. But... none of the theories so far support this idea, but none have tried either.
Todd
Todd, but the axial force component due to the side walls equals Sin[theta]*SideWallForce, where theta is the cone half-angle.  For theta = 0 ( a cylinder) the axial component due to the SideWallForce is Sin[0]*SideWallForce=0, it is zero no matter how large is the SideWallForce.  For small theta, the SideWallForce axial component is very low.  So, even if one grants you that the SideWallForce may be larger for small cone angle, the axial component is small.  Comments?

But, say Sin(Theta) were decreased by 1% value, how many additional bounces will that deliver? It's non-linear, so I don't know where the sweet spot is. Could a slightly lower cone angle provide much higher thrust because there are millions of more bounces at that angle? In other words, less thrust per bounce, but many more bounces. I don't know yet, but it is interesting and is yet "another" way of replacing Q with something else.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/08/2015 12:12 AM
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/08/2015 12:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414304#msg1414304">Quote from: rfmwguy on 08/08/2015 12:12 AM</a>
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.
YOU ROCK! Couldn't login for whatever reason. But no questions.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/08/2015 12:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414309#msg1414309">Quote from: SeeShells on 08/08/2015 12:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414304#msg1414304">Quote from: rfmwguy on 08/08/2015 12:12 AM</a>
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.
YOU ROCK! Couldn't login for whatever reason. But no questions.

Shell
Thanks Shell...it was fun...a dry run for the fulcrum test in a couple of weeks. Think we had 24 viewers, not bad for short notice only here on NSF.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Dasun on 08/08/2015 12:47 AM
Great work rfmwguy, watched the webcast and everything worked fine , look forward to the "real run" - best of luck!

And thanks to Dr Rodal for being a really effective ringmaster of this fringe circus!!!!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/08/2015 12:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414304#msg1414304">Quote from: rfmwguy on 08/08/2015 12:12 AM</a>
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.

Chat does not seem to work on iPad safari.  Will check out app...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: meberbs on 08/08/2015 01:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414182#msg1414182">Quote from: demofsky on 08/07/2015 06:49 PM</a>
Thinking about the ongoing controversy regarding TheTraveller's and Shawyer's theory raises a question for me.  Please forgive if this has been addressed in one of the earlier threads.

If Shawyer's theory is wrong then is Cullen's eqn 15 also incorrect??  Eqn 15 seems to be the bedrock of the theory (the bible they punch :D).

I am trying to unpack the controversy a bit from the recent standard of "the physics/theory is wrong".

Cullen is discussing a constant cross section wave guide the resonator that Shawyer is trying to analyze is a more complicated shape so Cullen's equation may or may not be applicable. There is probably something wrong with Shawyer's equation 7 since it ignores forces on the side walls. There are proofs in EM theory that show that EM waves will produces a time averaged net 0 force for any shape cavity, and any result that contradicts this either has incorrect math, or an assumption inconsistent with Maxwell's equations i.e. new physics.

If you are looking for a specific part of Shawyer's paper that is wrong, just after equation 7, he applies the special relativity velocity addition formula. This formula is used to transform the velocity of something measured in one reference frame to the velocity that object would appear to have in another reference frame.  Shawyer applies it to a random equation that he had rearranged to have a subtraction of velocities. He is not transforming reference frames, so applying the formula there is nonsense.

When he calculates the forces on the 2 plates separately for a waveguide moving at a different velocity, he is using the equation in the right context, but fails to account for the fact that he has to transform all of the variables into the moving reference frame. Some quantities that change are the cavity length, resonance frequency, injected frequency, and the energy stored in the waves. His claims of thrust reversing at a high fraction of the speed of light are a symptom of this misapplication of special relativity.

The fact that his paper's conclusions are completely wrong is sufficiently obvious to most experts that they don't even bother looking for what his specific mistakes are. The experimental results from multiple labs are another story, and those results are the only reason the EM drive is not completely dismissed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/08/2015 02:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414321#msg1414321">Quote from: meberbs on 08/08/2015 01:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414182#msg1414182">Quote from: demofsky on 08/07/2015 06:49 PM</a>
Thinking about the ongoing controversy regarding TheTraveller's and Shawyer's theory raises a question for me.  Please forgive if this has been addressed in one of the earlier threads.

If Shawyer's theory is wrong then is Cullen's eqn 15 also incorrect??  Eqn 15 seems to be the bedrock of the theory (the bible they punch :D).

I am trying to unpack the controversy a bit from the recent standard of "the physics/theory is wrong".

Cullen is discussing a constant cross section wave guide the resonator that Shawyer is trying to analyze is a more complicated shape so Cullen's equation may or may not be applicable. There is probably something wrong with Shawyer's equation 7 since it ignores forces on the side walls. There are proofs in EM theory that show that EM waves will produces a time averaged net 0 force for any shape cavity, and any result that contradicts this either has incorrect math, or an assumption inconsistent with Maxwell's equations i.e. new physics.

If you are looking for a specific part of Shawyer's paper that is wrong, just after equation 7, he applies the special relativity velocity addition formula. This formula is used to transform the velocity of something measured in one reference frame to the velocity that object would appear to have in another reference frame.  Shawyer applies it to a random equation that he had rearranged to have a subtraction of velocities. He is not transforming reference frames, so applying the formula there is nonsense.

When he calculates the forces on the 2 plates separately for a waveguide moving at a different velocity, he is using the equation in the right context, but fails to account for the fact that he has to transform all of the variables into the moving reference frame. Some quantities that change are the cavity length, resonance frequency, injected frequency, and the energy stored in the waves. His claims of thrust reversing at a high fraction of the speed of light are a symptom of this misapplication of special relativity.

The fact that his paper's conclusions are completely wrong is sufficiently obvious to most experts that they don't even bother looking for what his specific mistakes are. The experimental results from multiple labs are another story, and those results are the only reason the EM drive is not completely dismissed.

Excellent!.  Exactly the kind of detail I was looking for!  I think the discussion in this series of threads has reached a point where even folks who are not experts in this domain are interested in detailed critiques like this.

The detailed dialog of WarpTech and DeltaMass has given me a much deeper appreciation of what might or might not be happening.  Your excellent post also does this.  Thank you. 

And I certainly hope for more of this from both sides of the various controversies here! :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: watermod on 08/08/2015 03:05 AM
No matter if the EM drive theory fails or not I do have a more basic physics question.

Back up to a simple situation where my finger or something pushes something else.   The actual protons and neutrons (maybe electron clouds) do not touch (unless in a particle collision device like Fermi or Cern) so what wavefronts or fields are coming into play to transfer the force from the pusher object?    Strong? Weak? Gravity? Magnetic? Electrical? A mixture? 

Has touching like that been modeled down to the field level? 
Has its relationship to reference frames in space been modeled?

I keep thinking rocket exhaust throwing mass out the back of the rocket - what does it really imply for different reference planes and the structure of space. 

+ added later:   And then there is the bit with particles that don't react with reference frames or matter unless they do a head on collision like the neutrino flashes in huge pools of carbon-tet.    So what's the traction factor?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/08/2015 03:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414252#msg1414252">Quote from: WarpTech on 08/07/2015 08:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414221#msg1414221">Quote from: TheTraveller on 08/07/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd

So Dr. Ray Kwok is also wrong?

I see nothing incorrect about what Dr. Kwok said. He said "Resonators". An antenna is a resonator and so is a cavity. One is an open system, the other is a closed system. The preferred methods are different at a "National Standards" level, according to @rfmwguy. While I agree 100% that the experimenters to date have consistently used the S11 method, that does not mean it is the "standard" way to do it. You are arguing that "In the EM Drive world" this is how it's done. Perhaps this is true, but is no less true that this is NOT the "standard" way to do it.

Stop arguing about it and accept that fact please. You're driving everyone bonkers with your obstinance and defense of obvious incongruences. I do not follow others. I make mistakes, try to understand learn from them and forge my own path and from what I've seen, that is how most of us here operate.
Todd

My point is Shawyer, Prof Yang, Eagleworks & Prof Tajmar measured unloaded Q via a 1 port S11 3dB off the max return loss dB and frequency.

Why did they do it that way?

Because the cavity in operation has no load, no output port. A high Q cavity is like a high impedance parallel LC circuit where any external load on the circuit / cavity will introduce additional circuit / cavity losses and thus drop circuit / cavity Q.

The EMDrive operates as a high Q unloaded cavity and doing 2 port S21 cavity Q measurement, where the 2nd port or probe removes some of the cavity energy, which increases cavity losses, reducing unloaded Q, is just nuts.

I have explained why EMDrive cavity Q must be measured via unloaded via S11 return loss and how it is done. I also explained using a 2 port S21 can measure Q but it is not unloaded Q as the 2nd port sample probe increases cavity losses and reduces the unloaded cavity Q.

But hey do it your way as all these arm chair experts who have never built an EMDrive and got it to produce Force know better than Shawyer, Prof Yang, Eagleworks, Prof Tajmar's & Prof Tajmar's uW expert prof.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/08/2015 03:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414220#msg1414220">Quote from: WarpTech on 08/07/2015 07:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414213#msg1414213">Quote from: sghill on 08/07/2015 07:46 PM</a>
The testiness of this current discussion aside, I am genuinely interested in the reason why there is a difference between these two Q value viewpoints.

As far as I can gather, @TT is saying, "How they did it". @rfmwguy is saying "How it should've been done." and @tleach is saying "This is how it seems to fit McCulloch's formula."

Which BTW, McCulloch doesn't define how to measure Q. He simply redefines it as the number of bounces (reflections), in the time it takes the photon to decay to zero. So that's not even the same definition of the Q that is being kicked around here. @tleach was trying to bridge that gap.

What I conclude is, the experimenters may or may not be measuring it consistently using the same methodology, but in all cases, they are doing it wrong and should be using 2 ports to measure cavity resonance. We have yet to see anyone do it this way.
Todd

Can we simply agree to some notation to indicate which measurement scheme for Q we are talking about.  I'm sure there is a definitive answer for how to measure Q, but I get the feeling that deriving it involves complex math and probably deserves a paper of its own.  Can we simply agree on some way to easily notate which measuring scheme a poster is using and agree to disagree which is correct pending further data?

I mean hell, with the falloff in power requirements that TT was going on about on Reddit I'm not at all sure that the Q of the device isn't increasing the longer it is active.  (Which reminds me, has anybody pointed a geiger counter at one of these things to make sure it isn't throwing off unexpected radiation).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/08/2015 03:35 AM
Investing in Innovation for the Common Good

http://t.co/6feZnFeHlr

True for my totally open EMDrive work as well.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 04:11 AM
Jose,

In Zeng & Fan they define the complex wave number propagating toward the small end as;

k = j*α - β, where j is the imaginary coordinate.

Momentum is directly proportional to k. So the squared magnitude of the momentum vector is proportional to;

k2 = α2 +  β2

Now, take a gander at the plots for attenuation and phase constant in Zeng & Fan. Which mode and cone half-angle do you think will have the highest momentum?

For TE modes, as β goes to 0, the wave is 100% attenuated at the small end. They refer to this as the cut-off. 

Wouldn't you agree, that the waves have the highest momentum when the cone angle is smallest and k*r is the largest?

Also, if the attenuation, α is asymmetrical, would the equation above not (rather simply) explain beyond doubt why momentum transfer is also asymmetrical?

@TheTraveler likes to use Guide wavelength, rather than phase velocity. So be it. The guide wavelength is the inverse;

λguide = 2*pi/β

Per Z&F, as α increases, β goes to 0, the guide wavelength will become infinitely long and momentum of the wave goes to zero. It is 100% attenuated and absorbed at the front end.

Going the other way, toward the big end, β is increasing and α is decreasing rapidly. The momentum of the wave is increasing.

In both directions, the force on the frustum which balances the change in momentum is "forward". It is only the reflection at the big end that opposes this force. Anything that can be done to minimize the "z" component of this reflection, will add to the thrust.
Todd



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/08/2015 06:17 AM
SPR has declined my license request.

Too much red tape with using Chinese frustum fabricators and my Australian company would need to be approved by both UK and Australian Depts of Defense.

Oh well at least I tried to do the right thing.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/08/2015 06:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414342#msg1414342">Quote from: TheTraveller on 08/08/2015 06:17 AM</a>
SPR has declined my license request.

Too much red tape with using Chinese frustum fabricators and my Australian company would need to be approved by both UK and Australian Depts of Defense.

Oh well at least I tried to do the right thing.

As a practical matter will this affect you much?  Just trying to understand the implications of this.  Thanks!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/08/2015 06:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414343#msg1414343">Quote from: demofsky on 08/08/2015 06:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414342#msg1414342">Quote from: TheTraveller on 08/08/2015 06:17 AM</a>
SPR has declined my license request.

Too much red tape with using Chinese frustum fabricators and my Australian company would need to be approved by both UK and Australian Depts of Defense.

Oh well at least I tried to do the right thing.

As a practical matter will this affect you much?  Just trying to understand the implications of this.  Thanks!

Should have very little effect.

Was just trying to do the right thing by Shawyer / SPR and not be called out for ripping off the IP.

Told Shawyer I'll still give him / SPR 25% of any gross profit made.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/08/2015 06:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414344#msg1414344">Quote from: TheTraveller on 08/08/2015 06:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414343#msg1414343">Quote from: demofsky on 08/08/2015 06:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414342#msg1414342">Quote from: TheTraveller on 08/08/2015 06:17 AM</a>
SPR has declined my license request.

Too much red tape with using Chinese frustum fabricators and my Australian company would need to be approved by both UK and Australian Depts of Defense.

Oh well at least I tried to do the right thing.

As a practical matter will this affect you much?  Just trying to understand the implications of this.  Thanks!

Should have very little effect.

Was just trying to do the right thing by Shawyer / SPR and not be called out for ripping off the IP.

Told Shawyer I'll still give him / SPR 25% of any gross profit made.

So they'll still allow you manufacture in China/Australia and import the components?  That's good at least.  Bummer they won't let you give Shawyer some (financial) credit though...

EDIT: Oops!  Yeah, looks like you're going to give him 25%.  Sorry, it's getting late.  I misread that last line.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/08/2015 07:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414344#msg1414344">Quote from: TheTraveller on 08/08/2015 06:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414343#msg1414343">Quote from: demofsky on 08/08/2015 06:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414342#msg1414342">Quote from: TheTraveller on 08/08/2015 06:17 AM</a>
SPR has declined my license request.

Too much red tape with using Chinese frustum fabricators and my Australian company would need to be approved by both UK and Australian Depts of Defense.

Oh well at least I tried to do the right thing.

As a practical matter will this affect you much?  Just trying to understand the implications of this.  Thanks!

Should have very little effect.

Was just trying to do the right thing by Shawyer / SPR and not be called out for ripping off the IP.

Told Shawyer I'll still give him / SPR 25% of any gross profit made.

There is nothing to stop you from experimenting since you do believe in it.   That would be a better way to start anyway.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/08/2015 07:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414335#msg1414335">Quote from: WarpTech on 08/08/2015 04:11 AM</a>
Wouldn't you agree, that the waves have the highest momentum when the cone angle is smallest and k*r is the largest?

Did you change your mind about k*r? In previous thread you implied the opposite, that it had to be the lowest possible in order to increase thrust.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414335#msg1414335">Quote from: WarpTech on 08/08/2015 04:11 AM</a>
It is only the reflection at the big end that opposes this force. Anything that can be done to minimize the "z" component of this reflection, will add to the thrust.
Todd

Anything decreasing the reflection at the big end would also dramatically decrease the Q of the cavity. Do you think about a particular method? EDIT: slotting maybe ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/08/2015 10:19 AM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414304#msg1414304">Quote from: rfmwguy on 08/08/2015 12:12 AM</a>
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.

When you do the real thing are you going to publicise more widely?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/08/2015 01:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414284#msg1414284">Quote from: tleach on 08/07/2015 10:37 PM</a>
Quote from: rfmwguy link=topic=37642.msg1413139#msg1413139
Thermal tests done including 5 minute run at 30% power, which is what I'll use for fulcrum test. What I learned: Matching into frustum is good, magnetron ran at temperatures well below 200°C. Still had minor arcing, corrected it with full teardown and replacement of Db with mesh only, no copper clad. IOW, frustum is now all mesh except for Ds where magnetron is mounted. There was no arcing on Ds throughout any thermal testing. Plasma focused on Db, interestingly enough diagonally across from radome, not directly across axially.

@rfmwguy

"Thermal tests done including 5 minute run at 30% power, which is what I'll use for fulcrum test."  So you're actually putting in 30% of 900W which would be approximately 270W.

And then there's the conversion of electrical energy into microwave energy. If we assume that wikepedia is correct, a 900W microwave oven magnetron should run with approximately 64% efficiency. 

https://en.wikipedia.org/wiki/Microwave_oven#Heating_efficiency

That means you're magnetron is only putting 172.8W of energy into your frustum.  I'm officially revising my force prediction (based on my v3 spreadsheet and a projected S12 Q factor of 7000) down 43.41 mN. 

Sorry :-)
Hi Thor,
No, 30% is the amount of time power is at 100%, so it will "pulse" at full power for 30% of the time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/08/2015 01:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414358#msg1414358">Quote from: Star One on 08/08/2015 10:19 AM</a>

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414304#msg1414304">Quote from: rfmwguy on 08/08/2015 12:12 AM</a>
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.

When you do the real thing are you going to publicise more widely?
I dunno, Star, have given that some thought, even getting some of my film crew buddies out to the shop to document it 3rd-party...but have enough reservations remaining that I'll just let NSF pals spread the word themselves.

Should positive results be achieved, and I believe enough in them, I'll get a film crew out to professionally video it. I'm sure they or perhaps a local TV station would be interested in shooting a "mad scientist" feature spot.

Way too early for that. Getting them out for null results would be a bad deal for everyone. Besides, I have to clean up the shop first ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 01:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414335#msg1414335">Quote from: WarpTech on 08/08/2015 04:11 AM</a>
Jose,

In Zeng & Fan they define the complex wave number propagating toward the small end as;

k = j*α - β, where j is the imaginary coordinate.

Momentum is directly proportional to k. So the squared magnitude of the momentum vector is proportional to;

k2 = α2 +  β2

Now, take a gander at the plots for attenuation and phase constant in Zeng & Fan. Which mode and cone half-angle do you think will have the highest momentum?

For TE modes, as β goes to 0, the wave is 100% attenuated at the small end. They refer to this as the cut-off. 

Wouldn't you agree, that the waves have the highest momentum when the cone angle is smallest and k*r is the largest?

Also, if the attenuation, α is asymmetrical, would the equation above not (rather simply) explain beyond doubt why momentum transfer is also asymmetrical?

@TheTraveler likes to use Guide wavelength, rather than phase velocity. So be it. The guide wavelength is the inverse;

λguide = 2*pi/β

Per Z&F, as α increases, β goes to 0, the guide wavelength will become infinitely long and momentum of the wave goes to zero. It is 100% attenuated and absorbed at the front end.

Going the other way, toward the big end, β is increasing and α is decreasing rapidly. The momentum of the wave is increasing.

In both directions, the force on the frustum which balances the change in momentum is "forward". It is only the reflection at the big end that opposes this force. Anything that can be done to minimize the "z" component of this reflection, will add to the thrust.
Todd

Momentum is a vector.  What matters is the component of the momentum on the lateral walls acting along the longitudinal axis, so you have to multiply it by Sin[θ]:

Sin[θ]*MomentumLateralWalls     where θ=cone half-angle

(CavityShape.gif)

while the transverse components

Cos[θ]*MomentumLateralWalls

are self-cancelling (since the component on the left wall act in opposite direction to the one in the right wall).  Thus, if one assumes what you propose is correct (*), what matters is the vector component of momentum on the lateral walls, the component oriented along the longitudinal axis of the cone: Sin[θ]*Abs[k] where θ is the half-cone angle, so for θ=0, this component is zero.  Any finite magnitude multiplied by zero gives a zero result. So obviously a cylinder (θ=0) is the worst situation, as the longitudinal component of lateral-wall momentum is zero.  For θ=0, Sin[θ]*Abs[k] is zero, as θ increases, k decreases, but Sin[θ]  increases. As to what is the optimal value of the cone half-angle θ, one would have to calculate the expressions to find out. 

If you don't multiply the Momentum by Sin[θ], then one arrives at the wrong conclusion: that a cylinder is best.  To arrive at the correct conclusion, one has to multiply Momentum by Sin[θ].


(*) To know, one would have to calculate the Hankel functions and see how the absolute value of k varies as a function of cone angle θ and k r

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/08/2015 02:22 PM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414376#msg1414376">Quote from: rfmwguy on 08/08/2015 01:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414358#msg1414358">Quote from: Star One on 08/08/2015 10:19 AM</a>

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414304#msg1414304">Quote from: rfmwguy on 08/08/2015 12:12 AM</a>
http://www.ustream.tv/channel/em-drive-experiment

I am live on chat now at this address. You will need to create a free ustream account to post chat messages to me.

There is about a 30 second delay, be patient.

It is now 8:09 PM EST, I will keep it live and start about 8:20 PM to give people a chance to get there.

There will be some ustream sponsored commercials, be patient...its free streaming.

Chat with you in about 8 minutes.

When you do the real thing are you going to publicise more widely?
I dunno, Star, have given that some thought, even getting some of my film crew buddies out to the shop to document it 3rd-party...but have enough reservations remaining that I'll just let NSF pals spread the word themselves.

Should positive results be achieved, and I believe enough in them, I'll get a film crew out to professionally video it. I'm sure they or perhaps a local TV station would be interested in shooting a "mad scientist" feature spot.

Way too early for that. Getting them out for null results would be a bad deal for everyone. Besides, I have to clean up the shop first ;)

Good to hear and good luck with the tests.:)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/08/2015 02:40 PM

Not making any claims here, just reporting what I read. Keeping an open mind and poking around a bit.

Been reading up on how Shawyer "opens" up the Emdrive in his theory paper.

http://www.emdrive.com/theorypaper9-4.pdf

Specifically his use of Einstein's law of addition of velocities:

Quote
We note that if the forces had been the mechanical result of a working fluid
within the closed waveguide assembly, then the resultant force would merely
introduce a mechanical strain in the waveguide walls. This would be the result of a
closed system of waveguide and working fluid.
In the present system the working fluid is replaced by an electromagnetic
wave propagating close to the speed of light and Newtonian mechanics must be
replaced with the special theory of relativity. There are two effects to be considered
in the application of the special theory of relativity to the waveguide. The first effect
is that as the two forces Fg1 and Fg2 are dependent upon the velocities vg1 and vg2, the
thrust T should be calculated according to Einstein’s law of addition of velocities
given by

(2035aab1ba5af2e1ff296512b6a57779.png)

The second effect is that as the beam velocities are not directly dependent on
any velocity of the waveguide, the beam and waveguide form an open system. Thus
the reactions at the end plates are not constrained within a closed system of
waveguide and beam but are reactions between waveguide and beam, each operating
within its own reference frame, in an open system.
Source of image:
https://en.wikipedia.org/wiki/Velocity-addition_formula#Special_relativity

I remember reading lots of criticism for Shawyer using the addition of velocities from SR.

So I went looking around for where it is okay to use the addition of velocities. I went poking around to see what I could learn while keeping in mind that the EMdrives have air within the cavity with a refractive index not equal to 1 (1.000277) have been shown to present more thrust than airless cavities.

Ended up here:
https://en.wikipedia.org/wiki/Sagnac_effect (yeah I know, it's been brought up before)

Quote
When light propagates in fibre optic cable, the setup is effectively a combination of a Sagnac experiment and the Fizeau experiment. In glass the speed of light is slower than in vacuum, and the optical cable is the moving medium. In that case the relativistic velocity addition rule applies.

So it looks like the line in the sand is centered around the invariant speed of light in vacuum vs the speed of light in a medium (not a constant). Anyone able to mythbust any of this? Is the criticism that Shawyer is wrong in using the above addition of velocities warranted?

Which lead me to poke around looking for info related to the Fizeau experiment.
https://en.wikipedia.org/wiki/Fizeau_experiment (there was some dragging detected)

But then I was thinking of old Michelson-Morley experiment and those that followed:

https://en.wikipedia.org/wiki/Michelson%E2%80%93Gale%E2%80%93Pearson_experiment
http://www.kritik-relativitaetstheorie.de/Anhaenge/Wolfgang-Engelhardt-Sagnac.pdf (Originally posted in thread 2 by @Rodal)

So all I have to say after all that, it seems very important to see whether or not thrust differs when the frustum is oriented both parallel and perpendicular to Earth's rotation.



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/08/2015 04:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414383#msg1414383">Quote from: Mulletron on 08/08/2015 02:40 PM</a>
Not making any claims here, just reporting what I read. Keeping an open mind and poking around a bit.

Been reading up on how Shawyer "opens" up the Emdrive in his theory paper.

http://www.emdrive.com/theorypaper9-4.pdf

Specifically his use of Einstein's law of addition of velocities:

Quote
We note that if the forces had been the mechanical result of a working fluid
within the closed waveguide assembly, then the resultant force would merely
introduce a mechanical strain in the waveguide walls. This would be the result of a
closed system of waveguide and working fluid.
In the present system the working fluid is replaced by an electromagnetic
wave propagating close to the speed of light and Newtonian mechanics must be
replaced with the special theory of relativity. There are two effects to be considered
in the application of the special theory of relativity to the waveguide. The first effect
is that as the two forces Fg1 and Fg2 are dependent upon the velocities vg1 and vg2, the
thrust T should be calculated according to Einstein’s law of addition of velocities
given by

(2035aab1ba5af2e1ff296512b6a57779.png)

The second effect is that as the beam velocities are not directly dependent on
any velocity of the waveguide, the beam and waveguide form an open system. Thus
the reactions at the end plates are not constrained within a closed system of
waveguide and beam but are reactions between waveguide and beam, each operating
within its own reference frame, in an open system.
Source of image:
https://en.wikipedia.org/wiki/Velocity-addition_formula#Special_relativity

I remember reading lots of criticism for Shawyer using the addition of velocities from SR.

So I went looking around for where it is okay to use the addition of velocities. I went poking around to see what I could learn while keeping in mind that the EMdrives have air within the cavity with a refractive index not equal to 1 (1.000277) have been shown to present more thrust than airless cavities.

Ended up here:
https://en.wikipedia.org/wiki/Sagnac_effect (yeah I know, it's been brought up before)

Quote
When light propagates in fibre optic cable, the setup is effectively a combination of a Sagnac experiment and the Fizeau experiment. In glass the speed of light is slower than in vacuum, and the optical cable is the moving medium. In that case the relativistic velocity addition rule applies.

So it looks like the line in the sand is centered around the invariant speed of light in vacuum vs the speed of light in a medium (not a constant). Anyone able to mythbust any of this? Is the criticism that Shawyer is wrong in using the above addition of velocities warranted?

Which lead me to poke around looking for info related to the Fizeau experiment.
https://en.wikipedia.org/wiki/Fizeau_experiment (there was some dragging detected)

But then I was thinking of old Michelson-Morley experiment and those that followed:

https://en.wikipedia.org/wiki/Michelson%E2%80%93Gale%E2%80%93Pearson_experiment
http://www.kritik-relativitaetstheorie.de/Anhaenge/Wolfgang-Engelhardt-Sagnac.pdf (Originally posted in thread 2 by @Rodal)

So all I have to say after all that, it seems very important to see whether or not thrust differs when the frustum is oriented both parallel and perpendicular to Earth's rotation.
If you really want to dive deep, look at Orbital Angular Momentum of circular radiation:

http://arxiv.org/ftp/arxiv/papers/0905/0905.0190.pdf

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 05:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414377#msg1414377">Quote from: Rodal on 08/08/2015 01:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414335#msg1414335">Quote from: WarpTech on 08/08/2015 04:11 AM</a>
Jose,

In Zeng & Fan they define the complex wave number propagating toward the small end as;

k = j*α - β, where j is the imaginary coordinate.

Momentum is directly proportional to k. So the squared magnitude of the momentum vector is proportional to;

k2 = α2 +  β2

Now, take a gander at the plots for attenuation and phase constant in Zeng & Fan. Which mode and cone half-angle do you think will have the highest momentum?

For TE modes, as β goes to 0, the wave is 100% attenuated at the small end. They refer to this as the cut-off. 

Wouldn't you agree, that the waves have the highest momentum when the cone angle is smallest and k*r is the largest?

Also, if the attenuation, α is asymmetrical, would the equation above not (rather simply) explain beyond doubt why momentum transfer is also asymmetrical?

@TheTraveler likes to use Guide wavelength, rather than phase velocity. So be it. The guide wavelength is the inverse;

λguide = 2*pi/β

Per Z&F, as α increases, β goes to 0, the guide wavelength will become infinitely long and momentum of the wave goes to zero. It is 100% attenuated and absorbed at the front end.

Going the other way, toward the big end, β is increasing and α is decreasing rapidly. The momentum of the wave is increasing.

In both directions, the force on the frustum which balances the change in momentum is "forward". It is only the reflection at the big end that opposes this force. Anything that can be done to minimize the "z" component of this reflection, will add to the thrust.
Todd

Momentum is a vector.  What matters is the component of the momentum on the lateral walls acting along the longitudinal axis, so you have to multiply it by Sin[θ]:

Sin[θ]*MomentumLateralWalls     where θ=cone half-angle

(CavityShape.gif)

while the transverse components

Cos[θ]*MomentumLateralWalls

are self-cancelling (since the component on the left wall act in opposite direction to the one in the right wall).  Thus, if one assumes what you propose is correct (*), what matters is the vector component of momentum on the lateral walls, the component oriented along the longitudinal axis of the cone: Sin[θ]*Abs[k] where θ is the half-cone angle, so for θ=0, this component is zero.  Any finite magnitude multiplied by zero gives a zero result. So obviously a cylinder (θ=0) is the worst situation, as the longitudinal component of lateral-wall momentum is zero.  For θ=0, Sin[θ]*Abs[k] is zero, as θ increases, k decreases, but Sin[θ]  increases. As to what is the optimal value of the cone half-angle θ, one would have to calculate the expressions to find out. 

If you don't multiply the Momentum by Sin[θ], then one arrives at the wrong conclusion: that a cylinder is best.  To arrive at the correct conclusion, one has to multiply Momentum by Sin[θ].


(*) To know, one would have to calculate the Hankel functions and see how the absolute value of k varies as a function of cone angle θ and k r

But Z&F give k in the direction of r, not perpendicular to the axis. So the k value I'm using is already "in" that direction. What am I missing in Z&F that says otherwise?
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 05:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414407#msg1414407">Quote from: WarpTech on 08/08/2015 05:05 PM</a>
...But Z&F give k in the direction of r, not perpendicular to the axis. So the k value I'm using is already "in" that direction. What am I missing in Z&F that says otherwise?
Todd
In expression 9 of Zeng and Fan's paper

Electromagnetic fields and transmission properties in tapered hollow metallic waveguides

Xiahui Zeng and Dianyuan Fan

https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-17-1-34&id=175583

Zeng and Fan define k sub r in the r direction

Then suddenly in expressions 12, 13 and 14 they give an expression for gamma sub [θ ,φ] in terms of a k that has no subscript.

Ricvl has called these expressions 12 to 14 into question, as to whether they satisfy the Boundary Conditions.  I find it peculiar that Zeng and Fan dropped the r subscript in these expressions 12-14, and that they replace gamma with gamma sub [θ, φ]

 I have not re-derived them on my own to see whether they are correct, or whether they satisfy the Boundary Conditions or what does k stand for in these expressions.

From a physical standpoint it does not make any sense to me that the longitudinal component should be maximum for θ =0.  For  θ =0 the longitudinal component of momentum should be zero, so either Ricvl is correct that these expressions do not satisfy the Boundary Conditions, or gamma is not in the r direction.

Inspection of the subscript for gamma in equations 12 to 14 reveals that this is indeed the case.

The expressions 12 to 14 are labeled as gamma sub [θ, φ], therefore my interpretation is that they clearly are the components perpendicular to r, since the coordinates θ, φ are perpendicular to r.

Therefore it seems to me that a gamma component in the θ direction should be multplied by Sin[θ] to get the component in the longitudinal direction.

At the bottom of page 14, Zeng and Fan write:

Quote
Based on the Eqs. (12), (13) and (14), a variation of the attenuation α and phase constants β
for the spherical TE and TM modes as a function of kr with cone half-angle 0 θ as a
parameter has been studied and the results are presented in Figs. 2-5. 

So Figs.  2 to 5 that you are using to base your conclusions on, are based on gamma sub [ θ, φ ] instead of gamma sub r.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 05:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414409#msg1414409">Quote from: Rodal on 08/08/2015 05:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414407#msg1414407">Quote from: WarpTech on 08/08/2015 05:05 PM</a>
...But Z&F give k in the direction of r, not perpendicular to the axis. So the k value I'm using is already "in" that direction. What am I missing in Z&F that says otherwise?
Todd
In expression 9 of Zeng and Fan's paper

Electromagnetic fields and transmission properties in tapered hollow metallic waveguides

Xiahui Zeng and Dianyuan Fan

https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-17-1-34&id=175583

Zeng and Fan define k sub r in the r direction

Then suddenly in expressions 12, 13 and 14 they give an expression for gamma sub [θ ,φ] in terms of a k that has no subscript.

Ricvl has called these expressions 12 to 14 into question, as to whether they satisfy the Boundary Conditions.  I find it peculiar that Zeng and Fan droped the r subscript in these expressions 12-14, and that they replace gamma with gamma sub [θ, φ]

 I have not re-derived them on my own to see whether they are correct, or whether they satisfy the Boundary Conditions or what does k stand for in these expressions.

From a physical standpoint it does not make any sense to me that the longitudinal component should be maximum for θ =0.  For  θ =0 the longitudinal component of momentum should be zero, so either Ricvl is correct that these expressions do not satisfy the Boundary Conditions, or k in these expresssions is not k sub r and gamma is not in the r direction.

Inspection of the subscript for gamma in equations 12 to 14 reveals that this is indeed the case.

The expressions 12 to 14 are labeled as gamma sub [θ, φ], therefore my interpretation is that they clearly are the components perpendicular to r, since the coordinates θ, φ are perpendicular to r.

Therefore it seems to me that a gamma component in the θ direction should be multplied by Sin[θ] to get the component in the longitudinal direction.

Okay, back to the drawing board!
Thanks!
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 06:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414411#msg1414411">Quote from: WarpTech on 08/08/2015 05:46 PM</a>
...

Okay, back to the drawing board!
Thanks!
Todd

Please notice that while Fig. 2 and 3 in Zeng and Fan correspond to the electric field in the θ and φ directions, Fig 4 and 5 correspond to the electric field in the r direction.  Only the TM modes have an electric field in the r direction.

They define the attenuation only for the electric field, so they don't have a figure for magnetic field in the r direction corresponding to the TE modes.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/08/2015 06:14 PM
For those who are too skittish to be associated with doing Emdrive experiments, would recasting it as yet another Aether drag experiment sound any better?

https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment#Recent_optical_resonator_experiments

Have any recent experiments featured any intentional symmetry breaking?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/08/2015 06:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414414#msg1414414">Quote from: Mulletron on 08/08/2015 06:14 PM</a>
For those who are too skittish to be associated with doing Emdrive experiments, would recasting it as yet another Aether drag experiment sound any better?

https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment#Recent_optical_resonator_experiments

Have any recent experiments featured any intentional symmetry breaking?
Which kind of symmetry do you mean?
complex issue...

That's symmetry breaking par excellence, never the B field curls in the opposite direction while the current flows in the direction like in the drawing ;)

source of the picture: http://wiki.bnv-bamberg.de/flg-wiki/index.php/SchulheftPh9

Gravity is another example (till now there is only attractive force). :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/08/2015 07:23 PM
Parity and Time
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/08/2015 07:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414420#msg1414420">Quote from: Mulletron on 08/08/2015 07:23 PM</a>
Parity and Time
spontaneous symmetry breaking is the why we(and the universe) are here and the why we can ask such questions  8)

I will hope we will find out why symmetry is broken inside the conical cavity. May be it acts weak on some unknown scalar field in a asymmetrically way

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 07:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414413#msg1414413">Quote from: Rodal on 08/08/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414411#msg1414411">Quote from: WarpTech on 08/08/2015 05:46 PM</a>
...

Okay, back to the drawing board!
Thanks!
Todd

Please notice that while Fig. 2 and 3 in Zeng and Fan correspond to the electric field in the θ and φ directions, Fig 4 and 5 correspond to the electric field in the r direction.  Only the TM modes have an electric field in the r direction.

They define the attenuation only for the electric field, so they don't have a figure for magnetic field in the r direction corresponding to the TE modes.

Correct. The attenuation is on E perpendicular to the walls, since there is no radial component and no component tangential to the walls. However, the momentum in the r direction, depends on E perpendicular to r. So the attenuation of E perpendicular to r, affects the momentum in the r direction without multiplication by Sin(theta).

If you follow from equation 8 to 9, the expression j*kr=-(1/E)*dE/dr, is an expression for momentum in the r direction. To get momentum in the z direction, you would multiply by Cos(theta), but for small cone angles it's negligible.

Equation 8 is fairly straight forward, the wave is propagating in the r direction, and equation 9 shows it is expanding or contracting depending on direction. Take the derivative of 9 wrt t and multiply by Planck's constant to get the force, dp/dt. For which I get; (E is the electric field, not energy!!!)

Fr = -(hbar*kr/E)*dE/dt -j*hbar*d/dt(dE/dr)
    = -(hbar*kr/E)*dE/dt -j*(hbar/c)*d2E/dt2)  (I don't think I should use c here for dr/dt, but you get the idea. It's a wave equation.)

For Fz = Fr * Cos(theta)

Comments?
Todd
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 07:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414417#msg1414417">Quote from: X_RaY on 08/08/2015 06:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414414#msg1414414">Quote from: Mulletron on 08/08/2015 06:14 PM</a>
For those who are too skittish to be associated with doing Emdrive experiments, would recasting it as yet another Aether drag experiment sound any better?

https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment#Recent_optical_resonator_experiments

Have any recent experiments featured any intentional symmetry breaking?
Which kind of symmetry do you mean?
complex issue...

That's symmetry breaking par excellence, never the B field curls in the opposite direction while the current flows in the direction like in the drawing ;)

source of the picture: http://wiki.bnv-bamberg.de/flg-wiki/index.php/SchulheftPh9

Gravity is another example (till now there is only attractive force). :)

Gravity is the result of breaking the symmetry of the equilibrium power exchange, (photons, gluons, etc..) between particle-oscillators and the applicable ZPF. If you can produce a gradient in the opposite direction...
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 07:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414422#msg1414422">Quote from: WarpTech on 08/08/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414413#msg1414413">Quote from: Rodal on 08/08/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414411#msg1414411">Quote from: WarpTech on 08/08/2015 05:46 PM</a>
...

Okay, back to the drawing board!
Thanks!
Todd

Please notice that while Fig. 2 and 3 in Zeng and Fan correspond to the electric field in the θ and φ directions, Fig 4 and 5 correspond to the electric field in the r direction.  Only the TM modes have an electric field in the r direction.

They define the attenuation only for the electric field, so they don't have a figure for magnetic field in the r direction corresponding to the TE modes.

Correct. The attenuation is on E perpendicular to the walls, since there is no radial component and no component tangential to the walls. However, the momentum in the r direction, depends on E perpendicular to r. So the attenuation of E perpendicular to r, affects the momentum in the r direction without multiplication by Sin(theta).

If you follow from equation 8 to 9, the expression j*kr=-(1/E)*dE/dr, is an expression for momentum in the r direction. To get momentum in the z direction, you would multiply by Cos(theta), but for small cone angles it's negligible.

Equation 8 is fairly straight forward, the wave is propagating in the r direction, and equation 9 shows it is expanding or contracting depending on direction. Take the derivative of 9 wrt t and multiply by Planck's constant to get the force, dp/dt. For which I get; (E is the electric field, not energy!!!)

Fr = -(hbar*kr/E)*dE/dt -j*hbar*d/dt(dE/dr)
    = -(hbar*kr/E)*dE/dt -j*(hbar/c)*d2E/dt2)  (I don't think I should use c here for dr/dt, but you get the idea. It's a wave equation.)

For Fz = Fr * Cos(theta)

Comments?
Todd
 

I would have to re-derive them myself, but:

1) From a physical standpoint it does not make any sense to me that the longitudinal component should be maximum for θ =0.  For  θ =0 the longitudinal component of momentum should be zero, so either Ricvl is correct that these expressions do not satisfy the Boundary Conditions, or gamma is not in the r direction.

2) The expressions 12 to 13 are labeled as gamma sub [θ, φ], therefore my interpretation is that they clearly are the components perpendicular to r, since the coordinates θ, φ are perpendicular to r. Therefore it seems to me that a gamma component in the θ direction should be multplied by Sin[θ] to get the component in the longitudinal direction.

I have to re-derive them myself to make any further comments. #1 ( it does not make any sense to me that the longitudinal component should be maximum for θ =0 which implies that a cylinder is best) is a big obstacle in me being able to agree that it is correct without mulitplying by Sin[θ]

Sorry, I cannot take Zeng and Fan's results for granted if they imply that the longitudinal component of momentum should be maximum for θ =0

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/08/2015 07:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414424#msg1414424">Quote from: Rodal on 08/08/2015 07:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414422#msg1414422">Quote from: WarpTech on 08/08/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414413#msg1414413">Quote from: Rodal on 08/08/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414411#msg1414411">Quote from: WarpTech on 08/08/2015 05:46 PM</a>
...

Okay, back to the drawing board!
Thanks!
Todd

Please notice that while Fig. 2 and 3 in Zeng and Fan correspond to the electric field in the θ and φ directions, Fig 4 and 5 correspond to the electric field in the r direction.  Only the TM modes have an electric field in the r direction.

They define the attenuation only for the electric field, so they don't have a figure for magnetic field in the r direction corresponding to the TE modes.

Correct. The attenuation is on E perpendicular to the walls, since there is no radial component and no component tangential to the walls. However, the momentum in the r direction, depends on E perpendicular to r. So the attenuation of E perpendicular to r, affects the momentum in the r direction without multiplication by Sin(theta).

If you follow from equation 8 to 9, the expression j*kr=-(1/E)*dE/dr, is an expression for momentum in the r direction. To get momentum in the z direction, you would multiply by Cos(theta), but for small cone angles it's negligible.

Equation 8 is fairly straight forward, the wave is propagating in the r direction, and equation 9 shows it is expanding or contracting depending on direction. Take the derivative of 9 wrt t and multiply by Planck's constant to get the force, dp/dt. For which I get; (E is the electric field, not energy!!!)

Fr = -(hbar*kr/E)*dE/dt -j*hbar*d/dt(dE/dr)
    = -(hbar*kr/E)*dE/dt -j*(hbar/c)*d2E/dt2)  (I don't think I should use c here for dr/dt, but you get the idea. It's a wave equation.)

For Fz = Fr * Cos(theta)

Comments?
Todd
 

I would have to re-derive them myself, but:

1) From a physical standpoint it does not make any sense to me that the longitudinal component should be maximum for θ =0.  For  θ =0 the longitudinal component of momentum should be zero, so either Ricvl is correct that these expressions do not satisfy the Boundary Conditions, or gamma is not in the r direction.

2) The expressions 12 to 13 are labeled as gamma sub [θ, φ], therefore my interpretation is that they clearly are the components perpendicular to r, since the coordinates θ, φ are perpendicular to r. Therefore it seems to me that a gamma component in the θ direction should be multplied by Sin[θ] to get the component in the longitudinal direction.

I have to re-derive them myself to make any further comments. #1 ( it does not make any sense to me that the longitudinal component should be maximum for θ =0 which implies that a cylinder is best) is a big obstacle in me being able to agree that it is correct without mulitplying by Sin[θ]

Sorry, I cannot take Zeng and Fan's results for granted if they imply that the longitudinal component of momentum should be maximum for θ =0
You can't form a cylinder this way, r is the distance from the apex ;) that's never parallel. For the boundary conditions i have to think about, but your comment 2) make sense to me

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 07:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414425#msg1414425">Quote from: X_RaY on 08/08/2015 07:52 PM</a>
...
You can't form a cylinder this way, r is the distance from the apex ;) that's never parallel. For the boundary conditions i have to think about, but your comment 2) make sense to me
I had that discussion with Todd in a previous thread, where he wrote the same thing you wrote above. 
That's wrong.
I submitted a formal proof that a cylinder is the limit for r2 ->Infinity  with (r2 - r1) kept constant and theta -> 0.  Although I derived my proof independently you can also find in Euclidean geometry books, it emanates from the last of Euclid's postulate (parallell lines never meet) that is supplanted in Lobatchesky and Riemannian geometries.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 07:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414424#msg1414424">Quote from: Rodal on 08/08/2015 07:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414422#msg1414422">Quote from: WarpTech on 08/08/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414413#msg1414413">Quote from: Rodal on 08/08/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414411#msg1414411">Quote from: WarpTech on 08/08/2015 05:46 PM</a>
...

Okay, back to the drawing board!
Thanks!
Todd

Please notice that while Fig. 2 and 3 in Zeng and Fan correspond to the electric field in the θ and φ directions, Fig 4 and 5 correspond to the electric field in the r direction.  Only the TM modes have an electric field in the r direction.

They define the attenuation only for the electric field, so they don't have a figure for magnetic field in the r direction corresponding to the TE modes.

Correct. The attenuation is on E perpendicular to the walls, since there is no radial component and no component tangential to the walls. However, the momentum in the r direction, depends on E perpendicular to r. So the attenuation of E perpendicular to r, affects the momentum in the r direction without multiplication by Sin(theta).

If you follow from equation 8 to 9, the expression j*kr=-(1/E)*dE/dr, is an expression for momentum in the r direction. To get momentum in the z direction, you would multiply by Cos(theta), but for small cone angles it's negligible.

Equation 8 is fairly straight forward, the wave is propagating in the r direction, and equation 9 shows it is expanding or contracting depending on direction. Take the derivative of 9 wrt t and multiply by Planck's constant to get the force, dp/dt. For which I get; (E is the electric field, not energy!!!)

Fr = -(hbar*kr/E)*dE/dt -j*hbar*d/dt(dE/dr)
    = -(hbar*kr/E)*dE/dt -j*(hbar/c)*d2E/dt2)  (I don't think I should use c here for dr/dt, but you get the idea. It's a wave equation.)

For Fz = Fr * Cos(theta)

Comments?
Todd
 

I would have to re-derive them myself, but:

1) From a physical standpoint it does not make any sense to me that the longitudinal component should be maximum for θ =0.  For  θ =0 the longitudinal component of momentum should be zero, so either Ricvl is correct that these expressions do not satisfy the Boundary Conditions, or gamma is not in the r direction.

2) The expressions 12 to 14 are labeled as gamma sub [θ, φ], therefore my interpretation is that they clearly are the components perpendicular to r, since the coordinates θ, φ are perpendicular to r. Therefore it seems to me that a gamma component in the θ direction should be multplied by Sin[θ] to get the component in the longitudinal direction.

I have to re-derive them myself to make any further comments. #1 ( it does not make any sense to me that the longitudinal component should be maximum for θ =0 which implies that a cylinder is best) is a big obstacle in me being able to agree that it is correct without mulitplying by Sin[θ]

In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/08/2015 08:04 PM
I have a real concern with TheTraveller's Excel spreadsheet. The values I get from the first basic dimensions are inconsistent. I'm talking of the file EMDriveCalc20150617b.xls available from emdrive.wiki (http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools) as well as TT's Gdrive (https://drive.google.com/folderview?id=0B7kgKijo-p0ifk9EakZfbW9aZGMwNWZMQ01xVnBON0tkM2w0Q1NLbmtjRFFwMXBuNVlVN0U&usp=sharing#list).

Let's take know values, for example Eagleworks' frustum:
Db = 0.2794 m
Ds = 0.15875 m
Frustum length = 0.2286 m
cone half-angle = 14.78°

Input the first three values, and the spreadsheet returns a cone half-angle of 24.5° :(

Calculate the hypotenuse or draw the plan in a CAD software with the know values, you will easily get the frustum side length at 0.2364256 m. But the spreadsheet returns 0.2584848 m!

The formula for the cone half-angle (cell D8) in the spreadsheet is :
=DEGREES(ATAN((D3÷2)÷((D5×(D4÷2))+((D3÷2)−(D4÷2))+D5)))
Whereas it could use arccosine, frustum centre length (diameter center to diameter center) and frustum side length:
=DEGREES(ACOS(D5/D9)

Talking about the frustum side length (cell D9), its formula is wrong:
= SQRT(D5^2+(D3−D4)^2)
The correct formula should use end radii squared instead of end diameters squared:
= SQRT(D5^2+((D3−D4)÷2)^2)

How is the rest right or wrong? I can't even get Df right with the available spreadsheet. When inputing the Baby EmDrive data for example, Df becomes negative which is impossible (it should be comprised between 0 and 1) EDIT: my mistake, 24 GHz instead of 2.4 GHz resolved this issue.
Whatever, I don't get the same Df as TheTraveller for the same untouched spreadsheet and same input values. See fourth attachement below. Those differences are quite small, but everything else following in the spreadsheet gets very different values from those discrepancies.

@TheTraveller: can you please double-check those basic values in the spreadsheet, and upload a corrected version to the emdrive.wiki? This would be much appreciated by the EmDrive community :)

Below, I show two hypothesis for TT's EmDrive Mark 2, according to how the "Frustum centre length" is defined in the spreadsheet.
- The first with Frustum centre length = 208.71 mm has a cone half-angle (corrected formula) of 30°
- The second with Frustum centre length = 240.7 mm has a cone half-angle (corrected formula) of 26.6° (instead of 27.7° with the wrong angle formula).

What is important to note is that "Frustum centre length" as defined in the spreadsheet is the length between the centers of the two end diameters, and not the length defined by TheTraveller in his drawing where it is the apex r2-r1 length. All the misunderstanding comes from the difference in that drawing (attached in third position below).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/08/2015 08:06 PM
By the way those of you supporting the EM drive want an example of a theory that started out on the fringes but has gradually moved more centre wise then they only have to look at holographic theory for the universe.

http://www.sciencedaily.com/releases/2015/04/150427101633.htm
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 08:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/08/2015 08:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414426#msg1414426">Quote from: Rodal on 08/08/2015 07:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414425#msg1414425">Quote from: X_RaY on 08/08/2015 07:52 PM</a>
...
You can't form a cylinder this way, r is the distance from the apex ;) that's never parallel. For the boundary conditions i have to think about, but your comment 2) make sense to me
I had that discussion with Todd in a previous thread, where he wrote the same thing you wrote above. 
That's wrong.
I submitted a formal proof that a cylinder is the limit for r2 ->Infinity  with (r2 - r1) kept constant and theta -> 0.  Although I derived my proof independently you can also find in Euclidean geometry books, it emanates from the last of Euclid's postulate (parallell lines never meet) that is supplanted in Lobatchesky and Riemannian geometries.
Yeah right it's negligible for huge values of r, sometime the difference of r1 and r2 reach Plank length and there is no longer a difference in a physical sense.
For me this point is done!
Thanks Doc

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 08:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414335#msg1414335">Quote from: WarpTech on 08/08/2015 04:11 AM</a>
... Anything that can be done to minimize the "z" component of this reflection, will add to the thrust.
Todd
Since it is unlikely that I will have the time to re-derive Zeng and Fan's equations any time soon,  please allow me to pursue this (it is much less time consuming :)  )

1) What, specifically, can be done to minimize the "z component of the reflection at the Big End, to add to thrust?"

2) Do I understand you correctly that you think that the net force is pointing from the Big End towards the Small End? (in the opposite direction to Shawyer's thrust which he posits to be pointed from the Small End to the Big End?)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/08/2015 08:43 PM
need it 3D  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 09:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.


I think that you would not need to confirm anything more than equations 8 and 9. Forget the Hankel functions. Z&F say this equation for E is valid

Quote
For all electric field components of the spherical TE and TM modes mentioned previously, one can expressed them as... [equation 8]

You have the exact solution for E and H in a frustum cavity. Simply plug in the E vector into equation 9,

kr = j*(1/E)*dE/dr

where E is the electric field vector, all 3 components, which you already have in Mathematica. I think it should be just a few lines of code to take the derivative of a vector you already have, and multiply by the inverse. Once you have kr, take the derivative of that wrt time to get the force equation, and multiply by Cos(theta) to get the force in the z direction. No?
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 09:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414434#msg1414434">Quote from: Rodal on 08/08/2015 08:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414335#msg1414335">Quote from: WarpTech on 08/08/2015 04:11 AM</a>
... Anything that can be done to minimize the "z" component of this reflection, will add to the thrust.
Todd
Since it is unlikely that I will have the time to re-derive Zeng and Fan's equations any time soon,  please allow me to pursue this (it is much less time consuming :)  )

1) What, specifically, can be done to minimize the "z component of the reflection at the Big End, to add to thrust?"

2) Do I understand you correctly that you think that the net force is pointing from the Big End towards the Small End? (in the opposite direction to Shawyer's thrust which he posits to be pointed from the Small End to the Big End?)

1) At one time I suggested cutting slots in it to eliminate the DC component of current density. Settling for a lower Q and more leakage out the big end. Or a partially reflecting surface, like a Laser uses to allow a beam to escape. I am also thinking that the angle of incidence is important too, after looking at the Meep gifs. The energy does not appear to reflect perpendicular to the big end.

2a) I support the idea that dp/dt of the "frustum" is always forward, meaning small end leading.

2b) The dp/dt of the EM waves inside the frustum are such that dp/dt is positive when the wave is moving backwards, and negative when the wave is moving forward. So in one direction it is like "Shawyer's notion of thrust" and in the other direction it is like a solar wind behind a sail. Waves moving in BOTH directions, exert a force Forward on the frustum. It is only when the wave reflects from the big end that a force is being exerted that opposes that force.

I have calculated the DC B-field inside a frustum cavity and proven to myself that Maxwell's equations yield 0 net force on the system, provided I do not include any kind of nonlinear GR or PV affects on the permeability function. However, if the current is interrupted through the big end, i.e., if there is leakage flux escaping at the big end, then the force is asymmetrical.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/08/2015 09:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions, to respect the angular (theta) PEC boundary condition.

Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 09:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions.


Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/08/2015 09:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414428#msg1414428">Quote from: flux_capacitor on 08/08/2015 08:04 PM</a>
I have a real concern with TheTraveller's Excel spreadsheet. The values I get from the first basic dimensions are inconsistent. I'm talking of the file EMDriveCalc20150617b.xls available from emdrive.wiki (http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools) as well as TT's Gdrive (https://drive.google.com/folderview?id=0B7kgKijo-p0ifk9EakZfbW9aZGMwNWZMQ01xVnBON0tkM2w0Q1NLbmtjRFFwMXBuNVlVN0U&usp=sharing#list).

Let's take know values, for example Eagleworks' frustum:
Db = 0.2794 m
Ds = 0.15875 m
Frustum length = 0.2286 m
cone half-angle = 14.78°

Input the first three values, and the spreadsheet returns a cone half-angle of 24.5° :(

Calculate the hypotenuse or draw the plan in a CAD software with the know values, you will easily get the frustum side length at 0.2364256 m. But the spreadsheet returns 0.2584848 m!

The formula for the cone half-angle (cell D8) in the spreadsheet is :
=DEGREES(ATAN((D3÷2)÷((D5×(D4÷2))+((D3÷2)−(D4÷2))+D5)))
Whereas it could use arccosine, frustum centre length (diameter center to diameter center) and frustum side length:
=DEGREES(ACOS(D5/D9)

Talking about the frustum side length (cell D9), its formula is wrong:
= SQRT(D5^2+(D3−D4)^2)
The correct formula should use end radii squared instead of end diameters squared:
= SQRT(D5^2+((D3−D4)÷2)^2)

How is the rest right or wrong? I can't even get Df right with the available spreadsheet. When inputing the Baby EmDrive data for example, Df becomes negative which is impossible (it should be comprised between 0 and 1) >:(

@TheTraveller: can you please double-check those basic values in the spreadsheet, and upload a corrected version to the emdrive.wiki? This would be much appreciated by the EmDrive community :)

Below, I show two hypothesis for TT's EmDrive Mark 2, according to how the "Frustum centre length" is defined in the spreadsheet.
- The first with Frustum centre length = 208.71 mm has a cone half-angle (corrected formula) of 30°
- The second with Frustum centre length = 240.7 mm has a cone half-angle (corrected formula) of 26.6° (instead of 27.7° with the wrong angle formula).

What is important to note is that "Frustum centre length" as defined in the spreadsheet is the length between the centers of the two end diameters, and not the length defined by TheTraveller in his drawing where it is the apex r2-r1 length. All the misunderstanding comes from the difference in that drawing (attached in third position below).

Didn't the traveler say this came from Shawyer and SPR and the software they used?

Shell

P: Good catch //flux_capacitor

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/08/2015 10:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414429#msg1414429">Quote from: Star One on 08/08/2015 08:06 PM</a>
By the way those of you supporting the EM drive want an example of a theory that started out on the fringes but has gradually moved more centre wise then they only have to look at holographic theory for the universe.

http://www.sciencedaily.com/releases/2015/04/150427101633.htm
I honestly love this theory, simply it fits so much (but what do I know?). I've been following it for the last few months. Good post Star One!

I've been kicked out of the shop while other work goes on so I've been reading way too much tech.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/08/2015 10:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414435#msg1414435">Quote from: X_RaY on 08/08/2015 08:43 PM</a>
need it 3D  :)
Needs a Heat Shield......

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/08/2015 10:14 PM
Something has been bothering me since last night and I couldn't help but watching the modes change and flip in meep.

How can you calculate seriously any Q in a cavity that simply jumps around from one T mode decaying and building into another in such a short time? And they all do it, every simulation with varying speeds.

Just something to mull over on a day away from the shop.

Shell

Added: Back to lurk mode and I'll be quiet.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/08/2015 11:04 PM
If EmDrive "thrust" is an artifact of the experimental measurement process, as most people believe it is, then what is your favoured candidate for such an artifact?

I vote for thermal-related.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/08/2015 11:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions.


Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd

Not only half interger  order Todd, but a real order associated legendre and bessel functions.

I need go to a party now  ;D , but latter I will try explain better, but basicaly, boundary conditions under a adapted coordinate system  for the problem, are satisfied  only with the use of the free parameters of the general solution, and must have no dependence with the independent variables of the differential problem, or will not sove bc conditions and the differential equation simultaneously.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/08/2015 11:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414454#msg1414454">Quote from: SeeShells on 08/08/2015 10:14 PM</a>
Something has been bothering me since last night and I couldn't help but watching the modes change and flip in meep.

How can you calculate seriously any Q in a cavity that simply jumps around from one T mode decaying and building into another in such a short time? And they all do it, every simulation with varying speeds.

Just something to mull over on a day away from the shop.

Shell

Added: Back to lurk mode and I'll be quiet.

Excellent question.  I hope that you don't shy away from asking such questions because it is only this way that one can understand what is being output.

My understanding (aero to confirm) is that the quality factor is calculated by aero using the routine Harminv.

Please notice that Meep has this disclaimer for using Hamrinv to calculate the quality factor Q:

http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#Harminv

Quote
Important: normally, you should only use harminv to analyze data after the sources are off. Wrapping it in (after-sources (harminv ...)) is sufficient.

Thus, the Quality factor and the frequency (also obtained by Harminv) should properly be obtained after the sources are OFF, not when they are on. 

This takes us back to the whole discussion about Q quality factor in experiments.  The problem is not only how to best experimentally measure and report Q, but it seems not ideal to me to discuss and report a Q (as first done by Shawyer and then imitated by all other EM Drive experimenters) with the source ON.

It seems to me that proper measurement of Q also in experiments should be done upon turning the source off and examining the decay (as posted by Frobnicat in a separate post).

With the sources OFF, the definition of Q (inverse to damping) is well-posed.

With the sources ON, the meaning of Q is tricky.  It seems to me that when people are measuring Q with the sources on they are assuming a well-posed problem with "nice" properties (symmetry, etc.) that may not be fulfilled.  This is particularly contradictory with TheTraveller: who rejects Finite Element solutions (using COMSOL or ANSYS) and exact solutions of the problem saying that only a solution that calculates a force can properly calculate the frequency and at the same time Shawyer "measures" Q with the RF feed ON which assumes a well posed nice solution amenable to presentation of Q as if it would be the same Q as the one calculated with the RF feed off.

The way that the Q is being measured experimentally by Shawyer and others using S11 and the 3db width is similar to a common method in structural vibration analysis.  Of course, this presupposes a steady-state response.  In reality with the RF feed ON, the measurement may be a transient instead.

_______________________________________________________

QUESTION TO aero:  have you been calculating the quality factor Q with Harminv, and if so, have you been doing so with the sources ON or OFF.  Have you been wrapping with  (after-sources (harminv ...)) ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/08/2015 11:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414460#msg1414460">Quote from: Ricvil on 08/08/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd

Not only half interger  order Todd, but a real order associated legendre and bessel functions.

I need go to a party now  ;D , but latter I will try explain better, but basicaly, boundary conditions under a adapted coordinate system  for the problem, are satisfied  only with the use of the free parameters of the general solution, and must have no dependence with the independent variables of the differential problem, or will not sove bc conditions and the differential equation simultaneously.

Just tell me if equations 8 and 9 are correct or not please. It is a simple enough wave function and its first derivative. Is it representative of the electric field for TE and TM modes as they say, or isn't it? I don't need anything past equation 9 from Z&F to calculate the momentum and forces from the wave vector. @Rodal has an exact solution for the fields in his Mathematica program, and we have numbers from Meep. Therefore, regardless if Zeng and Fan derived those fields correctly, if equation 9 is correct, (which I think it is) then what's the problem? Just plug in the E vector from Mathematica or Meep, and its inverse, and take a couple of derivatives... and we have a force equation in both directions of propagation.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/08/2015 11:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414460#msg1414460">Quote from: Ricvil on 08/08/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.
Ui
Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions.


Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd

Not only half interger  order Todd, but a real order associated legendre and bessel functions.

I need go to a party now  ;D , but latter I will try explain better, but basicaly, boundary conditions under a adapted coordinate system  for the problem, are satisfied  only with the use of the free parameters of the general solution, and must have no dependence with the independent variables of the differential problem, or will not sove bc conditions and the differential equation simultaneously.
I opted out of a summer end party tonight mainly because Monday is a milestone birthday. Think I will celebrate with the sense that the next generation will question everything and challenge the status quo. Here's to nonconformity...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: garrybinder on 08/08/2015 11:43 PM
I love this thread and am totally addicted, can't put it down.  Thanks for all the work and information!  Discussions about Q, oxidation, broad / narrow spectrum and the shape of the ends have got me thinking about an alternate configuration.  It has many of the same characteristics but might be slightly easier to build / find parts / work with.  It is an ordinary cylinder with a cone inside.  Maybe something to consider once folks are enjoying consistent thrust (lifting small objects and pets, etc...  ;)

Keep up the great work!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 12:05 AM
(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQ_05_4foqMCaIOwvjdhDM9TC1aHo21AriJlRVkkOXgzXbncvpCCw)

The Eggcelerator
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 12:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414468#msg1414468">Quote from: garrybinder on 08/08/2015 11:43 PM</a>
I love this thread and am totally addicted, can't put it down.  Thanks for all the work and information!  Discussions about Q, oxidation, broad / narrow spectrum and the shape of the ends have got me thinking about an alternate configuration.  It has many of the same characteristics but might be slightly easier to build / find parts / work with.  It is an ordinary cylinder with a cone inside.  Maybe something to consider once folks are enjoying consistent thrust (lifting small objects and pets, etc...  ;)

Keep up the great work!

WELCOME to the thread.  :)

That looks similar to an early patent by Shawyer, as I recall Shawyer had a cylinder with a dielectric insert inside it in the shape of a cone.  Maybe somebody can find it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 12:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414467#msg1414467">Quote from: rfmwguy on 08/08/2015 11:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414460#msg1414460">Quote from: Ricvil on 08/08/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
Todd



I opted out of a summer end party tonight mainly because Monday is a milestone birthday. Think I will celebrate with the sense that the next generation will question everything and challenge the status quo. Here's to nonconformity...

Many years ago my first electronics teacher upon graduation from high school and before I set off to collage told me something I thought was kind of silly (you know 17 and so) HE said: "The is the golden age of mediocre conformity, never let yourself be trapped".  As I got older I realized what a gift of wisdom he had said.

Happy Birthday to a very non-mediocre person. :)

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 12:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414462#msg1414462">Quote from: Rodal on 08/08/2015 11:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414454#msg1414454">Quote from: SeeShells on 08/08/2015 10:14 PM</a>
Something has been bothering me since last night and I couldn't help but watching the modes change and flip in meep.

How can you calculate seriously any Q in a cavity that simply jumps around from one T mode decaying and building into another in such a short time? And they all do it, every simulation with varying speeds.

Just something to mull over on a day away from the shop.

Shell

Added: Back to lurk mode and I'll be quiet.

Excellent question.  I hope that you don't shy away from asking such questions because it is only this way that one can understand what is being output.

My understanding (aero to confirm) is that the quality factor is calculated by aero using the routine Harminv.

Please notice that Meep has this disclaimer for using Hamrinv to calculate the quality factor Q:

http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#Harminv

Quote
Important: normally, you should only use harminv to analyze data after the sources are off. Wrapping it in (after-sources (harminv ...)) is sufficient.

Thus, the Quality factor and the frequency (also obtained by Harminv) should properly be obtained after the sources are OFF, not when they are on. 

This takes us back to the whole discussion about Q quality factor in experiments.  The problem is not only how to best experimentally measure and report Q, but it seems not ideal to me to discuss and report a Q (as first done by Shawyer and then imitated by all other EM Drive experimenters) with the source ON.

It seems to me that proper measurement of Q also in experiments should be done upon turning the source off and examining the decay (as posted by Frobnicat in a separate post).

With the sources OFF, the definition of Q (inverse to damping) is well-posed.

With the sources ON, the meaning of Q is tricky.  It seems to me that when people are measuring Q with the sources on they are assuming a well-posed problem with "nice" properties (symmetry, etc.) that may not be fulfilled.  This is particularly contradictory with TheTraveller: who rejects Finite Element solutions (using COMSOL or ANSYS) and exact solutions of the problem saying that only a solution that calculates a force can properly calculate the frequency and at the same time Shawyer "measures" Q with the RF feed ON which assumes a well posed nice solution amenable to presentation of Q as if it would be the same Q as the one calculated with the RF feed off.

The way that the Q is being measured experimentally by Shawyer and others using S11 and the 3db width is similar to a common method in structural vibration analysis.  Of course, this presupposes a steady-state response.  In reality with the RF feed ON, the measurement may be a transient instead.

??????????????????????????????????????????????????????????

QUESTION TO aero:  have you been calculating the quality factor Q with Harminv, and if so, have you been doing so with the sources ON or OFF.  Have you been wrapping with  (after-sources (harminv ...)) ?

I've been researching this today and I've about reached one days brain drain.

Dr. Rodal, it's not only in meep that it's happening it's in the cavity as well, under power and I know It's driven by Maxwell's equations for a specific time set with in a finite computational defined area.

(http://ab-initio.mit.edu/wiki/index.php/Meep)
Resonant modes and frequencies — by analyzing the response of the system to a short pulse, one can extract the frequencies, decay rates, and field patterns of the harmonic modes of a system (including waveguide and cavity modes, and including losses).
--------------------
I feel there is much more going on that meep cannot show because of some of the inherent limitations. What I'd like to see is a round tube ends capped off as a resonate chamber with a RF input, measure the Q in meep.  Would you look at the CSV files from aero and do a simple compare of the Q and stress values between the two?

Maybe it's nothing but this old gal has a bone and maybe you have another way of looking at it. I think simply the decaying and mode switching in the frustum are a great red flag.

Back to lurk
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 01:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414488#msg1414488">Quote from: SeeShells on 08/09/2015 12:56 AM</a>
...I feel there is much more going on that meep cannot show because of some of the inherent limitations. What I'd like to see is a round tube ends capped off as a resonate chamber with a RF input, measure the Q in meep.  Would you look at the CSV files from aero and do a simple compare of the Q and stress values between the two? ...
Shell
Two possible ways to calculate Q from Meep, and none are possible at the moment with the output available:

1) To calculate the Q one needs to have access to all the Meep output: all the fields at all the nodes.  This is necessary to calculate the energy over the whole volume (which would be divided by the power loss on the copper surface). That output information is not available for any of the Meep runs.

2) Alternatively one could calculate the Q from the time decay with the RF feed off.  This cannot be done at the present time either because there has not been any runs with the RF feed off.  All the runs are with the RF feed ON, for a total of 0.013 microseconds (if my memory is correct).  During this time period there is no decay, on the contrary there is exponential magnification, so the calculated Q would be an imaginary number.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/09/2015 02:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414462#msg1414462">Quote from: Rodal on 08/08/2015 11:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414454#msg1414454">Quote from: SeeShells on 08/08/2015 10:14 PM</a>
Something has been bothering me since last night and I couldn't help but watching the modes change and flip in meep.

How can you calculate seriously any Q in a cavity that simply jumps around from one T mode decaying and building into another in such a short time? And they all do it, every simulation with varying speeds.

Just something to mull over on a day away from the shop.

Shell

Added: Back to lurk mode and I'll be quiet.

Excellent question.  I hope that you don't shy away from asking such questions because it is only this way that one can understand what is being output.

My understanding (aero to confirm) is that the quality factor is calculated by aero using the routine Harminv.

Please notice that Meep has this disclaimer for using Hamrinv to calculate the quality factor Q:

http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#Harminv

Quote
Important: normally, you should only use harminv to analyze data after the sources are off. Wrapping it in (after-sources (harminv ...)) is sufficient.

Thus, the Quality factor and the frequency (also obtained by Harminv) should properly be obtained after the sources are OFF, not when they are on. 

This takes us back to the whole discussion about Q quality factor in experiments.  The problem is not only how to best experimentally measure and report Q, but it seems not ideal to me to discuss and report a Q (as first done by Shawyer and then imitated by all other EM Drive experimenters) with the source ON.

It seems to me that proper measurement of Q also in experiments should be done upon turning the source off and examining the decay (as posted by Frobnicat in a separate post).

With the sources OFF, the definition of Q (inverse to damping) is well-posed.

With the sources ON, the meaning of Q is tricky.  It seems to me that when people are measuring Q with the sources on they are assuming a well-posed problem with "nice" properties (symmetry, etc.) that may not be fulfilled.  This is particularly contradictory with TheTraveller: who rejects Finite Element solutions (using COMSOL or ANSYS) and exact solutions of the problem saying that only a solution that calculates a force can properly calculate the frequency and at the same time Shawyer "measures" Q with the RF feed ON which assumes a well posed nice solution amenable to presentation of Q as if it would be the same Q as the one calculated with the RF feed off.

The way that the Q is being measured experimentally by Shawyer and others using S11 and the 3db width is similar to a common method in structural vibration analysis.  Of course, this presupposes a steady-state response.  In reality with the RF feed ON, the measurement may be a transient instead.

_______________________________________________________

QUESTION TO aero:  have you been calculating the quality factor Q with Harminv, and if so, have you been doing so with the sources ON or OFF.  Have you been wrapping with  (after-sources (harminv ...)) ?

   (set! sources  drivesrc-Gaus)
    (run-sources+ (* gc T_meep)  ; This time, # peroids, is for non-resonant frequencies dissapation (start-up).
    ; Lower Q, shorter time, higher Q, longer time before measurement made. Take your best guess.
        (after-sources (harminv Ez (vector3 0.05 0.05 0.05) fmeep BW 5)) )
    (exit)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 03:51 AM
A couple of key points I found about Harminv in this description of operational programing of Harminv in wiki.
---------------
(Quote)
Important: normally, you should only use harminv to analyze data after the sources are off. Wrapping it in (after-sources (harminv ...)) is sufficient. (end Quote)

Also.
Can we access this in meep to analyze?

(harminv-err result)


---------------
(Quote)
http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#Harminv

Harminv
The following step function collects field data from a given point and runs Harminv on that data to extract the frequencies, decay rates, and other information.
(harminv c pt fcen df [maxbands])
Returns a step function that collects data from the field component c (e.g. Ex, etc.) at the given point pt (a vector3). Then, at the end of the run, it uses Harminv to look for modes in the given frequency range (center fcen and width df), printing the results to standard output (prefixed by harminv:) as comma-delimited text, and also storing them to the variable harminv-results. The optional argument maxbands is the maximum number of modes to search for; defaults to 100.
Important: normally, you should only use harminv to analyze data after the sources are off. Wrapping it in (after-sources (harminv ...)) is sufficient.
In particular, Harminv takes the time series f(t) corresponding to the given field component as a function of time and decomposes it (within the specified bandwidth) as:
f(t) = \sum_n a_n e^{-i\omega_n t}
The results are stored in the list harminv-results, which is a list of tuples holding the frequency, amplitude, and error of the modes. Given one of these tuples, you can extract its various components with one of the accessor functions:
(harminv-freq result)
Return the complex frequency ω (in the usual Meep 2πc units).
(harminv-freq-re result)
Return the real part of the frequency ω.
(harminv-freq-im result)
Return the imaginary part of the frequency ω.
(harminv-Q result)
Return dimensionless lifetime, or "quality factor", Q, defined as -\mathrm{Re}\,\omega / 2 \mathrm{Im}\,\omega.
(harminv-amp result)
Return the complex amplitude a.
(harminv-err result)
A crude measure of the error in the frequency (both real and imaginary)...if the error is much larger than the imaginary part, for example, then you can't trust the Q to be accurate. Note: this error is only the uncertainty in the signal processing, and tells you nothing about the errors from finite resolution, finite cell size, and so on!
For example, (map harminv-freq-re harminv-results) gives you a list of the real parts of the frequencies, using the Scheme built-in map.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/09/2015 05:18 AM
Yes, analyse away: Data table is to wide to format nicely here, so a spread sheet is attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 05:38 AM
My Frustum dimensions, resonant frequency and Df are now locked and loaded:

Frustum big diameter       m   0.40000
Frustum small diameter   m   0.15900
Frustum centre length      m   0.24070
External Rf                      Hz   2,450,250,000
Calculated Df                   Df   0.857


The SPR and my resonance models agree to with-in 4.6MHz or 0.178% which is close enough for me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 05:46 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414468#msg1414468">Quote from: garrybinder on 08/08/2015 11:43 PM</a>
I love this thread and am totally addicted, can't put it down.  Thanks for all the work and information!  Discussions about Q, oxidation, broad / narrow spectrum and the shape of the ends have got me thinking about an alternate configuration.  It has many of the same characteristics but might be slightly easier to build / find parts / work with.  It is an ordinary cylinder with a cone inside.  Maybe something to consider once folks are enjoying consistent thrust (lifting small objects and pets, etc...  ;)

Keep up the great work!

See Shawyer's patent as attached.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 06:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414524#msg1414524">Quote from: aero on 08/09/2015 05:18 AM</a>
Yes, analyse away: Data table is to wide to format nicely here, so a spread sheet is attached.
So what are we seeing? Do you need for me to dig into it?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/09/2015 06:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414530#msg1414530">Quote from: SeeShells on 08/09/2015 06:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414524#msg1414524">Quote from: aero on 08/09/2015 05:18 AM</a>
Yes, analyse away: Data table is to wide to format nicely here, so a spread sheet is attached.
So what are we seeing? Do you need for me to dig into it?

You are seeing several cases of exactly what was described in your post above. If you want to analyse it, it is available. It tells me that the software thinks it is operating successfully, maybe it will tell you something different.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 06:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414428#msg1414428">Quote from: flux_capacitor on 08/08/2015 08:04 PM</a>
I have a real concern with TheTraveller's Excel spreadsheet. The values I get from the first basic dimensions are inconsistent. I'm talking of the file EMDriveCalc20150617b.xls available from emdrive.wiki (http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools) as well as TT's Gdrive (https://drive.google.com/folderview?id=0B7kgKijo-p0ifk9EakZfbW9aZGMwNWZMQ01xVnBON0tkM2w0Q1NLbmtjRFFwMXBuNVlVN0U&usp=sharing#list).

Let's take know values, for example Eagleworks' frustum:
Db = 0.2794 m
Ds = 0.15875 m
Frustum length = 0.2286 m
cone half-angle = 14.78°

Input the first three values, and the spreadsheet returns a cone half-angle of 24.5° :(

Calculate the hypotenuse or draw the plan in a CAD software with the know values, you will easily get the frustum side length at 0.2364256 m. But the spreadsheet returns 0.2584848 m!

The formula for the cone half-angle (cell D8) in the spreadsheet is :
=DEGREES(ATAN((D3÷2)÷((D5×(D4÷2))+((D3÷2)−(D4÷2))+D5)))
Whereas it could use arccosine, frustum centre length (diameter center to diameter center) and frustum side length:
=DEGREES(ACOS(D5/D9)

Talking about the frustum side length (cell D9), its formula is wrong:
= SQRT(D5^2+(D3−D4)^2)
The correct formula should use end radii squared instead of end diameters squared:
= SQRT(D5^2+((D3−D4)÷2)^2)

How is the rest right or wrong? I can't even get Df right with the available spreadsheet. When inputing the Baby EmDrive data for example, Df becomes negative which is impossible (it should be comprised between 0 and 1) EDIT: my mistake, 24 GHz instead of 2.4 GHz resolved this issue.
Whatever, I don't get the same Df as TheTraveller for the same untouched spreadsheet and same input values. See fourth attachement below. Those differences are quite small, but everything else following in the spreadsheet gets very different values from those discrepancies.

@TheTraveller: can you please double-check those basic values in the spreadsheet, and upload a corrected version to the emdrive.wiki? This would be much appreciated by the EmDrive community :)

Below, I show two hypothesis for TT's EmDrive Mark 2, according to how the "Frustum centre length" is defined in the spreadsheet.
- The first with Frustum centre length = 208.71 mm has a cone half-angle (corrected formula) of 30°
- The second with Frustum centre length = 240.7 mm has a cone half-angle (corrected formula) of 26.6° (instead of 27.7° with the wrong angle formula).

What is important to note is that "Frustum centre length" as defined in the spreadsheet is the length between the centers of the two end diameters, and not the length defined by TheTraveller in his drawing where it is the apex r2-r1 length. All the misunderstanding comes from the difference in that drawing (attached in third position below).

Thanks for finding that. Fixed. There may be other such errors as a lot of that work was done when I was taking strong pain killing tables. These formula are not involved in the resonance calc.

My resonant calc matches the SPR model by 0.178%, so I'm happy with that. They were 4.6MHz higher.

The frustum length is the distance in meters between the centre points of the end plates. If the end plates are spherical then the frustum side wall length is also the centre separation length.

Have modified the spreadsheet to show Vertex length and spherical end plate radius as attached.

Also modified the drawing to show the same data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 06:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414524#msg1414524">Quote from: aero on 08/09/2015 05:18 AM</a>
Yes, analyse away: Data table is to wide to format nicely here, so a spread sheet is attached.
No wonder it's too[sic] wide. You really don't want, or need, all those significant digits.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 06:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414473#msg1414473">Quote from: deltaMass on 08/09/2015 12:05 AM</a>

The Eggcelerator

Thanks for your eggcellent idea! Might want to run it through MEEP...JIK. It may crack interstellar flight.  8)

(Sorry couldn't resist, Good Morning!)
https://twitter.com/EggPuns/status/545618667481096193
Image: http://www.rt17.hr/teslas-egg-of-columbus/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/09/2015 06:46 AM

Quote
The Eggcelerator

Dimensions?

Frequency?

And where does the magnetron go?

Hey, sort of the right shape and everything.  A run through with MEEP probably wouldn't hurt anything.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 06:50 AM
Stranger things have happened. I looked at that "inverted cone" drawing and it sort of instantly generalised itself to an ovoid  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 07:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414541#msg1414541">Quote from: deltaMass on 08/09/2015 06:50 AM</a>
Stranger things have happened. I looked at that "inverted cone" drawing and it sort of instantly generalised itself to an ovoid  :)

Think that would do a better job of confining the fields to 1d. As per this:

http://www.pnas.org/content/111/29/10485.full (paper)
http://www.sciencedaily.com/releases/2014/07/140722091425.htm (newsy)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/09/2015 07:34 AM
Delta Mass...and others.

I keep coming back to David Bae's photon recycling laser two platform system.

To me, it looks like a weird photon rocket variant - yet one that produces thousands of times the amount of thrust a photon rocket should be able to produce.  It also appears legit.

With Bae's device you get around over unity / conservation of energy via redshift and a statement that only a small fraction of each photonic bounce is used for propulsion.   Yet, at the same time, another implication is missed:

For that to be true, the total energy potential of a photon would have to be many thousands of time greater than what the standard photon rocket calculations allow for.  Anybody care to dispute or comment on this?

Therefor, while the calculations for maximum thrust for the classic photon rocket are correct, you HAVE to allow for the possibility of much higher thrust IF the photons greater energy can be tapped.  Bae's device shows one way of doing this.   

Something else I have been wondering ever since Doctor Rodal first posted it.  Specifically, from MEEP based calculations and a program of his own, he stated that if the cavity had the right angle, the forces within it did three things:

1 - they went exponential, at least for the duration of the MEEP run (roughly 1/1000th of a second?)

2 - did not sum to zero, at least within that time period.  (But sooner or later, to satisfy the laws of thermodynamics, they would have to sum to zero).

3 - and these forces were nowhere near the levels reported in the EM Drive experiments.

So I have been wondering.  The relevant law of thermodynamics is Time Averaged.  Suppose this device breaks or twists the average, enough to where the 'step down cycle' doesn't kick in for say....several seconds, or even a minute.  That the forces within the EM Drive continued to build exponentially in mostly one direction not for just a few thousandths of a second, but several actual seconds.  Would the exponential force by that point be on a par with the typically reported results?

A larger wave or cycle of some sort.

Two other relevant tidbits here:

Best I can recollect, no EM Drive test has lasted more than a couple minutes.

Something that has been pointed out by Rodal, Paul March, and others:  maintaining the relevant frequency to produce thrust is a severe pain.  Suppose, due to something we cannot see at the moment, the frequency is impossible to maintain for whatever reason for more than a minute or two?  And must be reset afterwards.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 07:50 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414396#msg1414396">Quote from: rfmwguy on 08/08/2015 04:08 PM</a>

If you really want to dive deep, look at Orbital Angular Momentum of circular radiation:

http://arxiv.org/ftp/arxiv/papers/0905/0905.0190.pdf

You think it is converting OAM to LM in there?

Didn't someone detect rotation in MEEP a few pages back?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 07:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
.. maintaining the relevant frequency to produce thrust is a severe pain.  Suppose, due to something we cannot see at the moment, the frequency is impossible to maintain for whatever reason for more than a minute or two?  And must be reset afterwards.
I believe the reason to be purely thermal, and so it can be adjusted to remain on tune until the cows come home.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 07:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
Something that has been pointed out by Rodal, Paul March, and others:  maintaining the relevant frequency to produce thrust is a severe pain.  Suppose, due to something we cannot see at the moment, the frequency is impossible to maintain for whatever reason for more than a minute or two?  And must be reset afterwards.

By monitoring the VSWR of the driven frustum and automatically adjusting the freq every 50ms to find the lowest VSWR, it is possible to track any frustum resonant change and keep the freq in centre of the bandwidth, so to produce max Force.

Attached is my rough schematic of the Raspberry 2B based Control and Monitoring system I'm developing to do just that.

Should add that to get a low VSWR you need to 1st have a way to adjust the frustum's impedance to match that of the Rf generator, which in my case is a solid state 100W Rf amp. I will be using an inline coax 3 stub tuner as used by Paul at Eagleworks.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 08:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414550#msg1414550">Quote from: deltaMass on 08/09/2015 07:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
.. maintaining the relevant frequency to produce thrust is a severe pain.  Suppose, due to something we cannot see at the moment, the frequency is impossible to maintain for whatever reason for more than a minute or two?  And must be reset afterwards.
I believe the reason to be purely thermal, and so it can be adjusted to remain on tune until the cows come home.

720mNs of Force being generated by thermal radiation differential toward the small end?

Care to do the math as to what the surface temp differential of the big end to small end would need to be for that to happen? Lets assume Prof Yang's frustum had flat end plates but otherwise was similar to the attached.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/09/2015 08:04 AM

Quote
believe the reason to be purely thermal, and so it can be adjusted to remain on tune until the cows come home.

thermal is the usual reason cited. (should have included that). But should still be confirmed.

I take it, then, apart from that, you agree with or at least do not have any major issues with the rest of my reasoning?



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 08:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414553#msg1414553">Quote from: ThinkerX on 08/09/2015 08:04 AM</a>
Quote
believe the reason to be purely thermal, and so it can be adjusted to remain on tune until the cows come home.

thermal is the usual reason cited. (should have included that). But should still be confirmed.

I take it, then, apart from that, you agree with or at least do not have any major issues with the rest of my reasoning?
Well, I don't subscribe to the "borrowing energy for a long time" theory. Who would?
As for Bae, I'm still on the fence with that. I'll be staying there until I think I really understand it. Right now, I'm pretty sure I don't!

p.s. Watch your quotes. The admin police will be after you  :P

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/09/2015 08:41 AM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414452#msg1414452">Quote from: SeeShells on 08/08/2015 10:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414429#msg1414429">Quote from: Star One on 08/08/2015 08:06 PM</a>
By the way those of you supporting the EM drive want an example of a theory that started out on the fringes but has gradually moved more centre wise then they only have to look at holographic theory for the universe.

http://www.sciencedaily.com/releases/2015/04/150427101633.htm
I honestly love this theory, simply it fits so much (but what do I know?). I've been following it for the last few months. Good post Star One!

I've been kicked out of the shop while other work goes on so I've been reading way too much tech.

Shell

It's the fact that the maths fits so well to reality as we understand it. Also that they've now built an experiment to help prove the theory to detect an effect people might have never imagined before this could have existed. Rather like the EM drive.:)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/09/2015 09:11 AM

Quote
Well, I don't subscribe to the "borrowing energy for a long time" theory. Who would?

'borrowing energy?'  Where do you come up with that? 

The closest I came was in my commentary on Rodal's analysis of the MEEP results and his own independent program.  The claims there were the forces had a non-net-zero average, and were starting to go exponential. That was Rodal, not me.

I am merely wondering out loud if these forces continued on an exponential track for a few seconds they might not result in thrusts comparable to that reported by the experimenters. Are you taking issue with a simple extrapolation?


And yes, I suspect that something causes the exponentially increasing cycle to collapse or reverse itself after a while.  (a few seconds?  a minute?  two?)

Quote
As for Bae, I'm still on the fence with that. I'll be staying there until I think I really understand it. Right now, I'm pretty sure I don't!

Yet Bae's device has more experimental evidence going for it than the EM Drive. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/09/2015 09:23 AM
@TheTraveller: thanks, your Mark 2 drawing is consistent now. May you share the new spreadsheet on your Google Drive? Still the wrong one there.

But your cone half-angle is still wrong. Your frustum has a half-cone angle of 30.04°, not 27.7°. This is because the formula for the angle assumes the old version of Frustum centre length (Db to Ds) and not the new one (r2-r1).

Could you please share the new spreadsheet after this last correction?

Below, the confirmed version. We're finally in agreement…
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zero123 on 08/09/2015 10:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
With Bae's device you get around over unity / conservation of energy via redshift and a statement that only a small fraction of each photonic bounce is used for propulsion.   Yet, at the same time, another implication is missed:

For that to be true, the total energy potential of a photon would have to be many thousands of time greater than what the standard photon rocket calculations allow for.  Anybody care to dispute or comment on this?

This is correct and the mechanics behind it are well understood. A photon's energy-momentum relationship is given by: E = p*c, where E = the photon's energy, p = the photon's momentum and c = speed of light (in vacuum). So, what happens when you shine a laser out the back of the photon rocket? Each photon has momentum p and by conservation of momentum, your ship's momentum increases by -p (i.e. the momentum you add is the opposite of the photon's momentum) and the kinetic energy increases accordingly, only by a small fraction of the energy you spent on creating the photon. The energy of the departed photon is "wasted" in this case, as it should be for energy to be conserved.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
Therefor, while the calculations for maximum thrust for the classic photon rocket are correct, you HAVE to allow for the possibility of much higher thrust IF the photons greater energy can be tapped.  Bae's device shows one way of doing this. 

Right, in order to get more energy out of that same photon, it first has to come back to you after being reflected off of something. Then it can be reflected off of your ship giving you more momentum and so on. But the critical part here is that every time the photon gets reflected, its direction reverses and so it imparts momentum to the reflector in the direction the photon was moving and the opposite of the direction into which it is reflected.

So, each time, you will get more momentum in your desired direction and the reflector on the other side will get momentum in the opposite direction. Another such idea is to have the other reflector on the Earth as described by Meyer et al in "Laser Elevator: Momentum Transfer Using an Optical Resonator" and also explained by XKCD here: https://blog.xkcd.com/2008/02/15/the-laser-elevator/.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 12:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414557#msg1414557">Quote from: flux_capacitor on 08/09/2015 09:23 AM</a>
@TheTraveller: thanks, your Mark 2 drawing is consistent now. May you share the new spreadsheet on your Google Drive? Still the wrong one there.

But your cone half-angle is still wrong. Your frustum has a half-cone angle of 30.04°, not 27.7°. This is because the formula for the angle assumes the old version of Frustum centre length (Db to Ds) and not the new one (r2-r1).

Could you please share the new spreadsheet after this last correction?

Below, the confirmed version. We're finally in agreement…

Shared: https://drive.google.com/file/d/0B7kgKijo-p0iNjlZSmtuMHBzY28/view?usp=sharing

Has a better explanation on how to use it and how to use Goal Seek to find the resonant frequency.

Calcs Frustum slant angle correctly. This calc is not used in the spreadsheet.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 12:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414422#msg1414422">Quote from: WarpTech on 08/08/2015 07:35 PM</a>
...If you follow from equation 8 to 9, the expression j*kr=-(1/E)*dE/dr, is an expression for momentum in the r direction. ...
Comments?
Todd
I went over this reference again:

Electromagnetic fields and transmission properties in tapered hollow metallic waveguides

Xiahui Zeng and Dianyuan Fan

https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-17-1-34&id=175583

and I cannot agree that <<the expression j*kr=-(1/E)*dE/dr, is an expression for momentum in the r direction>>

The subscript "r" in kr does NOT indicate vector direction, instead it indicates that the scalar kr only depends on "r". 

Looking at equation (8) in page 38 of their article, you will notice that what they do is a separation of variables where they separate the dependence on "r" multiplicatively as an exponential that depends on r:

E(r,θ,φ) = A (θ,φ) e ^ [ - γ * r ]  (Notice that here the vector E is replaced by a scalar function E(r,θ,φ), as is usually done when solving the scalar Helmholtz equation)

where e ^ [ - γ * r ] shows:

* explicit dependence on r
* implicit dependence on r, since γ depends on r:  γ = γ (r)

Equations 8 and 9 are scalar equations.  Neither equations 8 or 9 are vector equations and a vector basis is not given, thus there is no vector dependence provided.  All that is being done here is a separation of variables of a scalar: the scalar E(r,θ,φ) is separated into two scalar variables: A and  e ^ [ - γ * r ], multiplying each other, where A does not depend on r, and  e ^ [ - γ * r ] only depends on r.

Zeng and Fan use the subscript "r' for k (and then they soon stop using it) just to indicate that k only depends on r, NOT that k is the vector component of a k vector.

Please notice that the solution of the problem comprises electromagnetic field vectors, where each electromagnetic component may have a dependence on any of the spherical components: r, θ, φ

Having a dependence on r, does NOT mean that the field is directed along "r"

For example, the vector component of the electric field in the φ direction, Eφ for TEmnp has a dependence on r, such that for p=1 it varies like half a wave pattern in the r direction, while for p=2 it varies with r as a full-wave pattern for example.  That does NOT mean that Eφ is directed along the r direction, it just indicates the r variation of the component Eφ that is directed along the φ direction (which is perpendicular to r).

To see the direction you have to express the electromagnetic fields as vectors using unit vectors (which Zeng and Fan don't show explicitly):

E =  Er er +  Eθ eθ + Eφ eφ

where in general, all three components depend on each three directions:

Er = Er (r,θ,φ)

Eθ = Eθ (r,θ,φ)

Eφ = Eφ (r,θ,φ)

here, dependence on r does not mean r direction of the vector:   Eθ (r,θ,φ) depends on r but it is not directed along r,  Eφ (r,θ,φ) depends on r but it is not directed along r. 

The momentum of  Eθ  is directed along θ. In general dEθ/dr  depends on r,θ and φ , but its momentum is directed along θ.

The momentum of  Eφ is directed along φ.  In general dEφ/dr  depends on r,θ and φ , but its momentum is directed along φ.

Only the momentum of  Er is directed along r, but there is no Er component in a TE mode.  Hence in a TE mode there is no E component with electric momentum directed along r.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 08/09/2015 12:42 PM
from thread 3  page 329
http://forum.nasaspaceflight.com/index.php?topic=37642.6560
quote rodal
"Here I present the Poynting vector field for the final 14 time slices.  It would be fun if somebody makes this into a movie"

So in movie form
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 01:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414555#msg1414555">Quote from: Star One on 08/09/2015 08:41 AM</a>
Also that they've now built an experiment to help prove the theory to detect an effect people might have never imagined before this could have existed.
I can't find any details on such an experiment. Link, please?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 01:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414533#msg1414533">Quote from: deltaMass on 08/09/2015 06:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414524#msg1414524">Quote from: aero on 08/09/2015 05:18 AM</a>
Yes, analyse away: Data table is to wide to format nicely here, so a spread sheet is attached.
No wonder it's too[sic] wide. You really don't want, or need, all those significant digits.
Another drive by Pasting.

I'm wondering if we could limit some of the overhead in meep right here... need to dig.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 01:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414576#msg1414576">Quote from: deltaMass on 08/09/2015 01:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414555#msg1414555">Quote from: Star One on 08/09/2015 08:41 AM</a>
Also that they've now built an experiment to help prove the theory to detect an effect people might have never imagined before this could have existed.
I can't find any details on such an experiment. Link, please?

http://holometer.fnal.gov/index.html

Don't see a connection to Emdrive unless their results somehow change our conservation laws.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 01:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414531#msg1414531">Quote from: aero on 08/09/2015 06:07 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414530#msg1414530">Quote from: SeeShells on 08/09/2015 06:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414524#msg1414524">Quote from: aero on 08/09/2015 05:18 AM</a>
Yes, analyse away: Data table is to wide to format nicely here, so a spread sheet is attached.
So what are we seeing? Do you need for me to dig into it?

You are seeing several cases of exactly what was described in your post above. If you want to analyse it, it is available. It tells me that the software thinks it is operating successfully, maybe it will tell you something different.
First look, I see a column with error on it and numbers beneath it. Why do you see it operating correctly aero? Is it because it gave Q's for those associated frequencies on the rows? What does that number in the error column mean?   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 01:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414536#msg1414536">Quote from: Mulletron on 08/09/2015 06:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414473#msg1414473">Quote from: deltaMass on 08/09/2015 12:05 AM</a>

The Eggcelerator

Thanks for your eggcellent idea! Might want to run it through MEEP...JIK. It may crack interstellar flight.  8)

(Sorry couldn't resist, Good Morning!)
https://twitter.com/EggPuns/status/545618667481096193
Image: http://www.rt17.hr/teslas-egg-of-columbus/
We all just See Shell. ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 01:51 PM
Think I got this correct.

Rotary table time to target RPM calculator screen shot as attached.

Looks like 4 minutes per 30 rpm, assuming very little air resistance due to a circular plastic air resistance shield that fits on the outer radius of the table base.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 02:06 PM
http://arxiv.org/abs/1508.00626

The Reality of Casimir Friction
K. A. Milton, J. S. Høye, I. Brevik

Theoretical consensus is emerging.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 02:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414591#msg1414591">Quote from: Mulletron on 08/09/2015 02:06 PM</a>
http://arxiv.org/abs/1508.00626

The Reality of Casimir Friction
K. A. Milton, J. S. Høye, I. Brevik

Theoretical consensus is emerging.

Thank you for posting this reference.  It would be very much appreciated any other references you may find on this subject (Casimir friction)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 02:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414550#msg1414550">Quote from: deltaMass on 08/09/2015 07:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
.. maintaining the relevant frequency to produce thrust is a severe pain.  Suppose, due to something we cannot see at the moment, the frequency is impossible to maintain for whatever reason for more than a minute or two?  And must be reset afterwards.
I believe the reason to be purely thermal, and so it can be adjusted to remain on tune until the cows come home.
It may be an analog of an "Electromagnetic Dean Drive" where the phenomenon may be due to the boundary conditions between the electromagnetic fields and the copper cavity instead of mechanical friction as a boundary condition between two solid surfaces.  Many things point towards this:

1) Shawyer acknowledging that nothing much can be measured unless there are background dynamic forces
2) Effect is much larger (orders of magnitude) with air than in a partial vacuum
3) Postprocessing stress tensor analysis of Meep with Wolfram Mathematica vis-a-vis exact solution analysis of stress tensor.

Don't know yet whether it may have any practical use in deep space (wouldn't it require a frame-dependent medium ? ).   Not ready to present the mathematics behind this.  Intuitively, I think it may be best understood by those working with elastic fluid flow (and the breaking of the no-slip boundary condition for fluids) than those working with electromagnetics.  The problem is that most work in electromagnetics does not analyze the stress tensor and the proper boundary conditions because electromagnetic stresses are so small (a very different situation from fluid flow, where the flow boundary conditions have been well studied for over a century).  The paper presented by Mulletron on Casimir friction is a big exception to this lack of discussion.  Encouraging to see Mulletron also looking at Casimir friction.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 02:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414550#msg1414550">Quote from: deltaMass on 08/09/2015 07:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414548#msg1414548">Quote from: ThinkerX on 08/09/2015 07:34 AM</a>
.. maintaining the relevant frequency to produce thrust is a severe pain.  Suppose, due to something we cannot see at the moment, the frequency is impossible to maintain for whatever reason for more than a minute or two?  And must be reset afterwards.
I believe the reason to be purely thermal, and so it can be adjusted to remain on tune until the cows come home.
I would expect thermal as well to be causing the drift, mode changes into ranges that cannot be recovered from. And you can't change the input frequency when the cavity has deformed in a non-uniform way. It can be defined further to localized hot spots on the end plates, those need to be addressed.

So I'm going to disclose just part of my next build.

Two step process. First a ceramic plate, nice stuff. Since they are down the road from me I've planned a visit. Did some work with them on their saws to cut those ceramics and I think I still have some good contacts there.
http://www.coorstek.com/markets/aerospace_defense/armor_protection.php

Then have it gold plated.
1300839663.jpg

Do the same for the small end plate.

This simple solution coupled with an active transducer feedback system in the small plate will keep the hot spots from warping the modes and changing the cavity resonance. The sidewall thermal expansion, which is a lateral down the length can be corrected by the small end transducer compensator.
   
I'm still using a heavier perforated copper on the sides (I'm going to be drilling the holes ... sigh for the sides to allow for greater cooling.

So what I hope to have is a non-super conducting very high Q cavity that doesn't shift modes and frequency demands, with a long run time.

On the methods used to hold resonance now. Even if I shift input frequencies the hot spots will have already caused an issue in mode deformation and a input frequency change will not address those. The only way is to maintain the endplates integrity is with this configuration and simply adjust the length of the cavity with the small end.

I've been thinking about this ever since Dr. Rodal sent me those images a couple months ago of the DUT by EagleWorks that showed the hotspots in simulation and the real world DUT. I was hoping to have a little more gofundme to start the build of this but it's not quite there yet.

This is the first time I have disclosed this idea of the second generation ERD ... Electromagnetic Reaction Drive except to mail it to someone else a bit ago. I would love to have inputs on what everyone thinks about it.

Shell

edit readibility

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 02:45 PM
@TheTraveller:
About that triple tuning stub - am I correct in assuming that this must be operated manually, or have you come up with a motorised solution?

As a general comment - when thermal effects drive the system off tune, there are in fact two independent adjustments to be made - a frequency adjustment to find the new resonance, and an impedance adjustment to minimise VSWR.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 03:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414605#msg1414605">Quote from: deltaMass on 08/09/2015 02:45 PM</a>
@TheTraveller:
About that triple tuning stub - am I correct in assuming that this must be operated manually, or have you come up with a motorised solution?

As a general comment - when thermal effects drive the system off tune, there are in fact two independent adjustments to be made - a frequency adjustment to find the new resonance, and an impedance adjustment to minimise VSWR.
In my second generation of the Electromagnetic Reaction Drive EMD, the first adjustment is the cavity length to the input frequency (a manual lead screw) then fine tune through the transducer compensator. Very simple. Once the VSWR is set in the very first run it should remain set in this configuration.

The whole key i this is the Magnetron and also why I was jazzed to find that simple way to stabilize it's output and also mod it to be a 100% duty cycle,

I'm keeping the hexagonal side walls simply because it leads to a very nice way to physically mount waveguides on the 180 degree sidewalls. Should give me a solid TE012.
Frequency and power stabilized magnetron 100% duty cycle
Symmetrical waveguide inputs (I hated seeing the microwaves being pushed around by the single input deforming the modes).  It's as simple as the incoming wave hitting a opposing wall of the cavity and bouncing at an obscure angle or the mode being pushed by the incoming wave pressures to switch physical positions. Seen this every since our first sim with meep. The only time is when we inserted the antenna into the endplates, that was very nice.

I figure I can at least double or more the force from a cavity by stabilizing these two variables.

Shell

boobboos

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 03:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414612#msg1414612">Quote from: SeeShells on 08/09/2015 03:15 PM</a>
...
I'm keeping the hexagonal side walls simply because it leads to a very nice way to physically mount waveguides on the 180 degree sidewalls. Should give me a solid TE012. ...
Is your first test EM Drive test going to have two symmetrically placed waveguides exciting the cavity or are you planing to use waveguides only in later tests?  (If so, how are you going to feed the RF on your first test?)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/09/2015 03:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
Then have it gold plated.
1300839663.jpg

Do the same for the small end plate.

Do you know the needed gold thickness for good resonance and high Q-factor, and if that firm can reach that requirement?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
This simple solution coupled with an active transducer feedback system in the small plate will keep the hot spots from warping the modes and changing the cavity resonance. The sidewall thermal expansion, which is a lateral down the length can be corrected by the small end transducer compensator.

Is this "transducer" similar to Shawyer's piezoelectric actuator (moving within a fraction of a millimeter) or is it a simpler and cheaper but slower system, like a stepper motor or a more expensive but more precise servomotor?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
So what I hope to have is a non-super conducting very high Q cavity that doesn't shift modes and frequency demands, with a long run time.

Does "a long run time" mean you want to make a rotary test like TheTraveller, to let the frustum accelerate?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
This is the first time I have disclosed this idea of the second generation ERD ... Electromagnetic Reaction Drive except to mail it to someone else a bit ago. I would love to have inputs on what everyone thinks about it.

Shell

This is exciting! :)

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414612#msg1414612">Quote from: SeeShells on 08/09/2015 03:15 PM</a>
Frequency and power stabilized magnetron 100% duty cycle
Symmetrical waveguide inputs (I hated seeing the microwaves being pushed around by the single input deforming the modes).  It's as simple as the incoming wave hitting a opposing wall of the cavity and bouncing at an obscure angle or the mode being pushed by the incoming wave pressures to switch physical positions. Seen this every since our first sim with meep. The only time is when we inserted the antenna into the endplates, that was very nice.

I figure I can at least double or more the force from a cavity by stabilizing these two variables.

Shell

You could increase the force even further, as your symmetrical double-input waveguide could allow two magnetrons operating at the same time, auto-tuning each other through a slaving process known as injection locking (https://en.wikipedia.org/wiki/Injection_locking).

See this prior post by ElizabethGreene (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1401433#msg1401433) in thread 3 for that matter, as well as this post by AnalogMan (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1397636#msg1397636) that has a reference paper attached. As it went almost unnoticed the first time, I attach again this document: "Noise Performance of Frequency- and Phase-Locked CW Magnetrons Operated as Current-Controlled Oscillators".

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 03:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414605#msg1414605">Quote from: deltaMass on 08/09/2015 02:45 PM</a>
@TheTraveller:
About that triple tuning stub - am I correct in assuming that this must be operated manually, or have you come up with a motorised solution?

As a general comment - when thermal effects drive the system off tune, there are in fact two independent adjustments to be made - a frequency adjustment to find the new resonance, and an impedance adjustment to minimise VSWR.

It is manually tuned.

Expected thermal frustum resonant freq changes should not cause much if any VSWR change but for sure it is an unknown. The data collection and logging system should show if there is any forward power to frustum thermal heating to resonant freq to VSWR change and to what extent, if any, it changes.

Power is only max 100W and the wall and end plate thickness are 2mm oxygen free copper so the frustum should be fairly dimensionally stable at this power level. BTW the outside of the frustum will be painted with a pot belly wood stove high carbon black paint to aid heat radiation and reduce thermal movement.

Copper expands approx 0.0167mm/m/degC. For a 20 deg C temp increase (25C to 45C which will never happen), averaged over the entire frustum side wall area, with a starting length of 0.2407m, would result in a 0.08mm increase in length. Would have very little measurable effect on frustum resonance nor on impedance tuning.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 03:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414613#msg1414613">Quote from: Rodal on 08/09/2015 03:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414612#msg1414612">Quote from: SeeShells on 08/09/2015 03:15 PM</a>
...
I'm keeping the hexagonal side walls simply because it leads to a very nice way to physically mount waveguides on the 180 degree sidewalls. Should give me a solid TE012. ...
Is your first test EM Drive test going to have two symmetrically placed waveguides exciting the cavity or are you planing to use waveguides only in later tests?  (If so, how are you going to feed the RF on your first test?)
The opposed waveguides are on the second revised frustum. Have the copper for it. Still working on the waveguides and ceramics and another magnetron and power supply.

Somewhat simple process to couple into a coaxial cable which is then going to be run into the frustum to dual dipole antennas in the frustum supported by a ceramic rod through the sidewalls. The nice thing about a cavity with holes in it I can pop the antenna(s) anywhere I want quite easily.

I was thinking about this dual configuration. see pic. I'm still working on the actual placement but I'm using a 1/16" ceramic rod that fits very tightly onto the holes on the side walls to support the antenna. By the time the Rf gets to the antennas I'll be dealing with maybe 30 watts of RF. Not like the magnetron waveguide into the sidewalls.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 04:06 PM
So for say TE01X modes, what kind of beam is that? Is it a Gaussian beam? Or a Laguerre-Gaussian beam? Jim Beam?

In return, here's some info on resonant cavity accelerators:
http://uspas.fnal.gov/materials/09UNM/ResonantCavities.pdf (big file be patient)

Also in there is info to end the S-parameter fight from page 1.

S11 VSWR (Translated to English means measuring at input port only.) (This test should reflect conditions one would expect when the frustum is in operation so keep sample port high Z. In my test, since the sample port was "hobbled" aka just solder cup, it didn't make a difference if it was terminated, shorted, or even left open.)

S21 Measure Q via transmission method. (Input to output) (You gotta have a well matched sample port for the test. What I did after the test was "hobble" the sample port by just leaving a stubby solder cup. This was also recommended by Star-Drive. I quickly realized that since I'm interested in NOT coupling energy back out of the cavity, I had to hobble the sample port.)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 04:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414614#msg1414614">Quote from: flux_capacitor on 08/09/2015 03:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
Then have it gold plated.
1300839663.jpg

Do the same for the small end plate.

Do you know the needed gold thickness for good resonance and high Q-factor, and if that firm can reach that requirement?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
This simple solution coupled with an active transducer feedback system in the small plate will keep the hot spots from warping the modes and changing the cavity resonance. The sidewall thermal expansion, which is a lateral down the length can be corrected by the small end transducer compensator.

Is this "transducer" similar to Shawyer's piezoelectric actuator (moving within a fraction of a millimeter) or is it a simpler and cheaper but slower system, like a stepper motor or a more expensive but more precise servomotor?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
So what I hope to have is a non-super conducting very high Q cavity that doesn't shift modes and frequency demands, with a long run time.

Does "a long run time" mean you want to make a rotary test like TheTraveller, to let the frustum accelerate?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414600#msg1414600">Quote from: SeeShells on 08/09/2015 02:33 PM</a>
This is the first time I have disclosed this idea of the second generation ERD ... Electromagnetic Reaction Drive except to mail it to someone else a bit ago. I would love to have inputs on what everyone thinks about it.

Shell

This is exciting! :)

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414612#msg1414612">Quote from: SeeShells on 08/09/2015 03:15 PM</a>
Frequency and power stabilized magnetron 100% duty cycle
Symmetrical waveguide inputs (I hated seeing the microwaves being pushed around by the single input deforming the modes).  It's as simple as the incoming wave hitting a opposing wall of the cavity and bouncing at an obscure angle or the mode being pushed by the incoming wave pressures to switch physical positions. Seen this every since our first sim with meep. The only time is when we inserted the antenna into the endplates, that was very nice.

I figure I can at least double or more the force from a cavity by stabilizing these two variables.

Shell

You could increase the force even further, as your symmetrical double-input waveguide could allow two magnetrons operating at the same time, auto-tuning each other through a slaving process known as injection locking (https://en.wikipedia.org/wiki/Injection_locking).

See this prior post by ElizabethGreene (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1401433#msg1401433) in thread 3 for that matter, as well as this post by AnalogMan (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1397636#msg1397636) that has a reference paper attached. As it went almost unnoticed the first time, I attach again this document: "Noise Performance of Frequency- and Phase-Locked CW Magnetrons Operated as Current-Controlled Oscillators".

I know about the dual phase locked magnetrons and that will be in the third series tests. first is to see if I can truly be stable and control the environment in this second series.

No. not like TT's Simply if I ramp up the thrusts like the designs in the third level with dual magnetrons I should be hitting a high acceleration and rotational rate in a almost frictionless air bearing (my design)  rotary table and that is another issue, plus a lot more money. No, it as simple for me to monitor thrust pressures on my test platform and then remove the scales and time the acceleration for a given distance with the same test and test platform. No I'm after thrust measurements from a long burn. ;)

BTW: the magnetron is just popped into the frustum for looks.

The pizo is OTS and after I posted a PM to someone here I read that RS's next was going to be using the same idea. interesting hum?

Added: The pizoelectric is an OTS and I will drive it with a simple Pi, very cool little board. http://www.amazon.com/gp/product/B00PWYK2V6?psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00
 
Added after shower.. lol
Ys I'm very aware of the thickness of gold and who can do it and I'm going to hold that one close for now and the actual ceramic I'll be using. Sorry

shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/09/2015 04:11 PM
Interesting Russian EMDrive like patent:
http://bankpatentov.ru/node/123593

and comment received on Reddit EMDrive forum:
https://www.reddit.com/r/EmDrive/comments/3ceyjv/email_from_roger_shawyer/ctww6rd

As Dr. Vladimir Leonov claims the "Shawyer Effect" works via the QV, Dr. White might be interested.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 04:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414620#msg1414620">Quote from: Mulletron on 08/09/2015 04:06 PM</a>
So for say TE01X modes, what kind of beam is that? Is it a Gaussian beam? Or a Laguerre-Gaussian beam? Jim Beam?

In return, here's some info on resonant cavity accelerators:
http://uspas.fnal.gov/materials/09UNM/ResonantCavities.pdf (big file be patient)

Also in there is info to end the S-parameter fight from page 1.

S11 VSWR (Translated to English means measuring at input port only.) (This test should reflect conditions one would expect when the frustum is in operation so keep sample port high Z. In my test, since the sample port was "hobbled" aka just solder cup, it didn't make a difference if it was terminated, shorted, or even left open.)

S21 Measure Q via transmission method. (Input to output) (You gotta have a well matched sample port for the test. What I did after the test was "hobble" the sample port by just leaving a stubby solder cup. This was also recommended by Star-Drive. I quickly realized that since I'm interested in NOT coupling energy back out of the cavity, I had to hobble the sample port.)

Right now it's a Jim Bean... I'm having a birthday party today and do have to get going to set up. I'll be back a little later to detail out more. Thanks for the link, I think I know these guys. ;)

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 04:28 PM
It just occurred to me while I was typing all that out. I bet I could use that sample port as a way to tune the cavity somehow. Not sure how. Any ideas? Is there something I could screw onto the N-F connector which would allow me to use it as a tuner?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/09/2015 04:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414624#msg1414624">Quote from: Mulletron on 08/09/2015 04:28 PM</a>
It just occurred to me while I was typing all that out. I bet I could use that sample port as a way to tune the cavity somehow. Not sure how. Any ideas? Is there something I could screw onto the N-F connector which would allow me to use it as a tuner?

Yes, just use an amplifier and the sample port as the input signal. Start with a pulse that "rings" inside the frustum at resonance. Take the output from the sample port and feed it into the input of the amplifier. Then feed the output of the amplifier back into the frustum. The output of the amplifier will "track" the resonance of the chamber automatically, due to the feedback loop. No mechanical adjustments required.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/09/2015 04:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414396#msg1414396">Quote from: rfmwguy on 08/08/2015 04:08 PM</a>

If you really want to dive deep, look at Orbital Angular Momentum of circular radiation:

http://arxiv.org/ftp/arxiv/papers/0905/0905.0190.pdf

The reason I'm asking about beams is because I'm following up on @rfmwguy's reference above, specifically this quote from it:

Quote
3.3 Laguerre-Gaussian Beams
In order to endow our EM beam with orbital angular momentum, let us search for
a solution of the Helmholtz equation with an azimuthal e−il' dependence because,
according to Simpson et al. [46], such a beam will carry OAM. Let us use our uG
25

https://en.wikipedia.org/wiki/Orbital_angular_momentum_of_light#cite_ref-1

edit:
I'm somewhat confused by this whole beam situation. Maybe it is Bessel beams.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/09/2015 05:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414620#msg1414620">Quote from: Mulletron on 08/09/2015 04:06 PM</a>
So for say TE01X modes, what kind of beam is that? Is it a Gaussian beam? Or a Laguerre-Gaussian beam? Jim Beam?

In return, here's some info on resonant cavity accelerators:
http://uspas.fnal.gov/materials/09UNM/ResonantCavities.pdf (big file be patient)

Also in there is info to end the S-parameter fight from page 1.

S11 VSWR (Translated to English means measuring at input port only.) (This test should reflect conditions one would expect when the frustum is in operation so keep sample port high Z. In my test, since the sample port was "hobbled" aka just solder cup, it didn't make a difference if it was terminated, shorted, or even left open.)

S21 Measure Q via transmission method. (Input to output) (You gotta have a well matched sample port for the test. What I did after the test was "hobble" the sample port by just leaving a stubby solder cup. This was also recommended by Star-Drive. I quickly realized that since I'm interested in NOT coupling energy back out of the cavity, I had to hobble the sample port.)
In and out for some supplies.

Look at the piece of RF equipment behind me in the picture... :). It was the start of it all for the SSC.
http://www.gofundme.com/yy7yz3k
Back to the party. Ya'll have a great Sunday (if in your time zone).

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: BL on 08/09/2015 06:22 PM
TheTraveller provided this link re some Russian work on microwave thrusters:

Interesting Russian EMDrive like patent:
http://bankpatentov.ru/node/123593


Wonder if that is related to this little (~0.3 m) Russian spacecraft, with no announced purpose, that was launched in May of 2014 with three other spacecraft and has apparently been scurrying around in orbit visiting some of the other payloads/booster. 

http://conspiracy-cafe.blogspot.com/2015/03/kosmos-2499-is-it-spy-or-assassin-or.html

Lots of speculation as to its purpose, but, given its small size, not much speculation about how it was doing its ‘scurrying’.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/09/2015 06:39 PM
Just to bring it back to the surface : is any one going to try with Matglas 2714A at the big end?
To see if extreme magnetic permeability has any impact on EMdrive performances?

If too expensive, a second option would be an iron plate ( as noted on the wiki list : (99.95% pure Fe annealed in H) )
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 06:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414649#msg1414649">Quote from: BL on 08/09/2015 06:22 PM</a>
TheTraveller provided this link re some Russian work on microwave thrusters:

Interesting Russian EMDrive like patent:
http://bankpatentov.ru/node/123593


Wonder if that is related to this little (~0.3 m) Russian spacecraft, with no announced purpose, that was launched in May of 2014 with three other spacecraft and has apparently been scurrying around in orbit visiting some of the other payloads/booster. 

http://conspiracy-cafe.blogspot.com/2015/03/kosmos-2499-is-it-spy-or-assassin-or.html

Lots of speculation as to its purpose, but, given its small size, not much speculation about how it was doing its ‘scurrying’.

Great link about the little Russian spacecraft (Kosmos-2499), thanks.

May not be related, because TheTraveller also gave this link to a comment received on Reddit EMDrive forum from somebody claiming to be the author of the Russian EMDrive-like invention:

https://www.reddit.com/r/EmDrive/comments/3ceyjv/email_from_roger_shawyer/ctww6rd

where somebody claiming to be the patent's author (http://bankpatentov.ru/node/123593)
 writes:

Quote
  I suggest along with Shawyer establish an independent international company in Cyprus with the participation of enthusiasts of new space technologies. Funding for this project can be ensured. I am ready to participate in the project.
Dr. Vladimir Leonov
...

I doubt that somebody involved in a Russian Defense Department project (Kosmos-2499) would be posting in Reddit (given his name, e-mail address and phone number) suggesting to << along with Shawyer establish an independent international company >> in a foreign country (Cyprus) known as a haven to escape Russian taxes (http://www.nytimes.com/2014/02/18/business/international/russian-business-target-of-cypriot-bailout-still-loves-the-island.html?_r=0).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 07:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414656#msg1414656">Quote from: Flyby on 08/09/2015 06:39 PM</a>
Just to bring it back to the surface : is any one going to try with Matglas 2714A at the big end?
To see if extreme magnetic permeability has any impact on EMdrive performances?

If too expensive, a second option would be an iron plate ( as noted on the wiki list : (99.95% pure Fe annealed in H) )

This is particularly suitable for TE (transverse electric) modes, because they have a magnetic field in the axial direction.  Thus it may be something that SeeShells may want to consider if she succeeds in exciting a TE mode.

TE modes ==> particularly suitable to a ferromagnetic end (magnetic field in longitudinal direction)

TM modes ==> particularly suitable to a dielectric end (electric field in longitudinal direction)
                                                                          (as used for example by NASA Eagleworks)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/09/2015 07:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414576#msg1414576">Quote from: deltaMass on 08/09/2015 01:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414555#msg1414555">Quote from: Star One on 08/09/2015 08:41 AM</a>
Also that they've now built an experiment to help prove the theory to detect an effect people might have never imagined before this could have existed.
I can't find any details on such an experiment. Link, please?

It's in the link I originally posted on this topic up thread.

Posted again for ease of reference.

http://motherboard.vice.com/read/there-is-growing-evidence-that-our-universe-is-a-giant-hologram

Quote
The actual experiment that will decipher this involves measuring the relative positions of large mirrors separated by 40 meters, using two Michelson laser interferometers with a precision 1 billion times smaller than an atom. If, as according to the holographic noise hypothesis, information about the positions of the two mirrors is finite, then the researchers should ultimately hit a limit in their ability to resolve their respective positions.

“What happens then?” Lanza said. “We expect to simply measure noise, as if the positions of the optics were dancing around, not able to be pinned down with more precision. So in the end, the experimental signature we are looking for is an irreducible noise floor due to the universe not actually storing more information about the positions of the mirrors.”

The team is currently collecting and analyzing data, and expects to have their first results by the end of the year. Lanza told me they are encouraged by the fact that their instruments have achieved by far the best sensitivity ever to gravitational waves at high frequencies.

“The physics of gravitational waves is unrelated to holographic noise, however, the gravity wave results demonstrate that our instrument is operating at top notch science quality, and we are now poised to experimentally dig into the science of holographic noise,” Lanza said.


You can find more details & relevant links here.

http://www.sciencedaily.com/releases/2015/04/150427101633.htm

Here's the paper.

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.114.111602

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/09/2015 07:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414658#msg1414658">Quote from: Rodal on 08/09/2015 07:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414656#msg1414656">Quote from: Flyby on 08/09/2015 06:39 PM</a>
Just to bring it back to the surface : is any one going to try with Matglas 2714A at the big end?
To see if extreme magnetic permeability has any impact on EMdrive performances?

If too expensive, a second option would be an iron plate ( as noted on the wiki list : (99.95% pure Fe annealed in H) )

This is particularly suitable for TE (transverse electric) modes, because they have a magnetic field in the axial direction.  Thus it may be something that SeeShells may want to consider if she succeeds in exciting a TE mode.

TE modes ==> particularly suitable to a ferromagnetic end

TM modes ==> particularly suitable to a dielectric end (as used for example by NASA Eagleworks)
The russian patent is hard to read even with automatic translation, but quite interesting :)
µ, epsilon dependence make sense
The same like in the picture for the E-field is true for the H-field using high µ_r

I remember there was a discussion based on permeability and susceptibility and losses in the last thread.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/09/2015 07:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414438#msg1414438">Quote from: WarpTech on 08/08/2015 09:03 PM</a>
...
You have the exact solution for E and H in a frustum cavity. Simply plug in the E vector into equation 9,

kr = j*(1/E)*dE/dr

where E is the electric field vector, all 3 components, which you already have in Mathematica. I think it should be just a few lines of code to take the derivative of a vector you already have, and multiply by the inverse.

My solution is in terms of real valued functions (Spherical Bessel functions), while Zeng and Fan used the complex-valued spherical Hankel functions (or Spherical Bessel functions of the third kind -same thing-).

A complex valued solution is needed to separate the real and imaginary terms alpha and beta.  So I would need to spend the time to re-cast the solution in terms of complex-valued Spherical Hankel functions (or Spherical Bessel functions of the third kind -same thing-).  To do this I would need to review Hankel functions (I think that they are usually used for theoretical work to express outward- and inward-propagating wave solutions of the wave equation) and make sure that all the terms are correct, including defining factors.   

***************

I still think that you can use Zeng and Fan's results, the only difference is that you have to multiply the results in Fig 2 and Fig 3 by Sin[θ] to get the momentum component in the longitudinal direction, but I haven't checked this.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/09/2015 08:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions.


Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd

Sorry Todd, Dr Rodal and all people from this forum.

My fault. The zeng and fan field solutions are  correct and the table 1 shows the order of associated legendre/bessel functions for some values of cone angle thetazero.

But together,the definitions in ( 8 ), (9) , (10), (11), (12), (13), and (14) make no sense to me.
A "constant" kr while defining the exponential in ( 8 ) and (9) , or in other words, kr is not a function of any spatial variable at this point, but becomes  a function of r later.

The same for "constant"  gamma definition in (10) and (11).

Suddenly, these "constants" becomes functions in (12), (13) and (14).
Magic?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/09/2015 09:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414549#msg1414549">Quote from: Mulletron on 08/09/2015 07:50 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414396#msg1414396">Quote from: rfmwguy on 08/08/2015 04:08 PM</a>

If you really want to dive deep, look at Orbital Angular Momentum of circular radiation:

http://arxiv.org/ftp/arxiv/papers/0905/0905.0190.pdf

You think it is converting OAM to LM in there?

Didn't someone detect rotation in MEEP a few pages back?
Its possible oam is the reason for force variants in different orientations. IOW cosmic speed limit might create a localized force to shed photon speed. Obviously not sure but the brick wall of C is there in our reference frame...in which we are in orbital motion...something to ponder perhaps.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: leomillert on 08/09/2015 09:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414595#msg1414595">Quote from: Rodal on 08/09/2015 02:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414591#msg1414591">Quote from: Mulletron on 08/09/2015 02:06 PM</a>
http://arxiv.org/abs/1508.00626

The Reality of Casimir Friction
K. A. Milton, J. S. Høye, I. Brevik

Theoretical consensus is emerging.

Thank you for posting this reference.  It would be very much appreciated any other references you may find on this subject (Casimir friction)

Found some.

Casimir friction force and energy dissipation for moving harmonic oscillators - J. S. Høye; I. Brevik

Casimir friction at zero and finite temperatures - Høye, Johan S.; Brevik, Iver (2014)

Macroscopic approach to the Casimir friction force - V. V. Nesterenko,A. V. Nesterenko (2014)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/09/2015 10:07 PM
I can understand the attraction of taking the idea of Casimir friction in order to explain an EmDrive as some sort of Zero-Point Dean Drive. A pawl and ratchet into spacetime. What I don't understand is how people can make such a proposal when there is no Casimir effect in an EmDrive in the first place.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/09/2015 11:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414676#msg1414676">Quote from: Ricvil on 08/09/2015 08:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions.


Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd

Sorry Todd, Dr Rodal and all people from this forum.

My fault. The zeng and fan field solutions are  correct and the table 1 shows the order of associated legendre/bessel functions for some values of cone angle thetazero.

But together,the definitions in ( 8 ), (9) , (10), (11), (12), (13), and (14) make no sense to me.
A "constant" kr while defining the exponential in ( 8 ) and (9) , or in other words, kr is not a function of any spatial variable at this point, but becomes  a function of r later.

The same for "constant"  gamma definition in (10) and (11).

Suddenly, these "constants" becomes functions in (12), (13) and (14).
Magic?

Agreed, they misuse the word "constant" when pertaining to the variables, alpha and beta. It is a terminology issue though, not math that is incorrect.

It is not magic. Equation 12 is the derivative of equation 2, per equations 9 and 10, for TE modes. Equations 13 and 14 are the derivatives of equation 5, for TM modes. Since there is no component of Er in equation 2, there is no radial component of attenuation for the E field in the r direction. But there is for the TM mode, in equation 5 to give equation 14.

Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 01:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414698#msg1414698">Quote from: WarpTech on 08/09/2015 11:58 PM</a>
...
Agreed, they misuse the word "constant" when pertaining to the variables, alpha and beta. It is a terminology issue though, not math that is incorrect.

It is not magic. Equation 12 is the derivative of equation 2, per equations 9 and 10, for TE modes. Equations 13 and 14 are the derivatives of equation 5, for TM modes. Since there is no component of Er in equation 2, there is no radial component of attenuation for the E field in the r direction. But there is for the TM mode, in equation 5 to give equation 14.

Todd

It may be interesting to plot the γ function, the logarithmic gradient of the electric field:

γ = - dLog[E]/dr = - (1/E)*dE/dr

defined by Zeng and Fan, and apply it to the case of standing waves in a closed resonant cavity: Yang/Shell for TE011 and TE012, to see what it looks like.

In this case γ = γθ = γφ

γθ = - (1/Eθ)*dEθ/dr = γφ = - (1/Eφ)*dEφ/dr

γ is real, these are standing waves hence there is no imaginary component of γ.

γ grows without bounds, to Infinity, at each end because the transverse electric fields are zero at the big base and at the small base in order to satisfy the boundary condition that electric fields parallel to a metal boundary must be zero.  Since γ is defined as the ratio of the gradient of the electric field with respect to r, divided by the electric field, when the field is zero at the bases, while the numerator is maximum, γ is infinite at the boundaries.

For TE012, γ also grows without bounds at the middle node of the two half-wave patterns because at that point the transverse electric field is zero while its gradient with respect to r is maximum.

Notice that γ is negative at the small base (small r) and positive at the big base (large r).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/10/2015 01:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414698#msg1414698">Quote from: WarpTech on 08/09/2015 11:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414676#msg1414676">Quote from: Ricvil on 08/09/2015 08:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414449#msg1414449">Quote from: WarpTech on 08/08/2015 09:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414448#msg1414448">Quote from: Ricvil on 08/08/2015 09:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414430#msg1414430">Quote from: Rodal on 08/08/2015 08:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414427#msg1414427">Quote from: WarpTech on 08/08/2015 07:58 PM</a>
...
In a cylinder, the longitudinal component of momentum is the wave propagating down the waveguide. The momentum is in the z direction, not radial toward the walls. In Z&F, they are depicting a waveguide, not a cavity. The momentum is propagating down the waveguide. Changing the angle > 0, changes the momentum in the z direction for a tapered waveguide, relative to a cylindrical waveguide. In the case of the wave moving toward the apex, what Z&F show is that the waves are attenuated and all of the momentum in the z direction is phase shifted and absorbed.

Essentially, attenuation of the E field in the perpendicular directions, "IS" attenuation of momentum in the r direction, because Sr = E x H perpendicular to S. The wave traveling toward the apex is losing momentum to the waveguide, in the z direction. The wave traveling toward the big end is gaining momentum in the z direction. In a cylinder, neither is true because the wave does not change momentum in either direction. So the k-vector reflecting off the wall is not (theta, phi) in Z&F, it is in the r direction. So it is r*Cos(theta) to get z direction thrust.
Todd

A cylinder is a geometrical concept.  It is perfectly OK for me to speak of a cylinder as something that has open ends, it carries no implications of a being a cavity.

As to Zeng and Fan, as I said, I would have to re-derive their equations and see whether they satisfy the boundary conditions (Ricvl said that they don't) or if there is something else amiss.

Yes Dr Rodal, to me Zeng and Fan don't write the correct expressions for the problem of propagation on a tapered conical waveguide.

One way is solve the helmoltz equations respecting directly  the physical boundary conditions under the  geometry of problem.
This will implies that standard solutions of wave equation in spherical coordinates ( in general, bessel and legendre functions  of integer order),  must be subtituted by  specific solutions with fractionary order legendre/ bessel functions.


Other way, more complicated, is find solutions using the called "coupled-mode theory in instantaneous eigenmode (quasimode) basis ", where one can use a superposition cilindrical modes, evolving a coupled-mode equation along the longitudinal axis of propagation, where each cilindrical mode has a instantaneous dependence on the radii of tapered section of conical waveguide.

Of course, there are many others forms to solve this problem.

I set to bold because, to my understanding, this is precisely what they did. Look at equations 2 & 3, and the associated text that follows it, through to equation 8. This part of their work is not that difficult to follow, so I don't see precisely where they make any error or assumptions that would cause it to be wrong. Their answer includes everything you just said, and the derivatives are Hankel functions of "fractional order". Where is the error?
Todd

Sorry Todd, Dr Rodal and all people from this forum.

My fault. The zeng and fan field solutions are  correct and the table 1 shows the order of associated legendre/bessel functions for some values of cone angle thetazero.

But together,the definitions in ( 8 ), (9) , (10), (11), (12), (13), and (14) make no sense to me.
A "constant" kr while defining the exponential in ( 8 ) and (9) , or in other words, kr is not a function of any spatial variable at this point, but becomes  a function of r later.

The same for "constant"  gamma definition in (10) and (11).

Suddenly, these "constants" becomes functions in (12), (13) and (14).
Magic?

Agreed, they misuse the word "constant" when pertaining to the variables, alpha and beta. It is a terminology issue though, not math that is incorrect.

It is not magic. Equation 12 is the derivative of equation 2, per equations 9 and 10, for TE modes. Equations 13 and 14 are the derivatives of equation 5, for TM modes. Since there is no component of Er in equation 2, there is no radial component of attenuation for the E field in the r direction. But there is for the TM mode, in equation 5 to give equation 14.

Todd

If one has a function with exponential format F=exp(k.x) and k is a constant then one can write k=(dF/dx)/F.

But if one has a function F=exp(k(x).x) then (dF/dx)/F=k(x) + xdk(x)/dx

If F has no exponential format is worse.

The wave solutions in spherical coodinates are the form  exp(+ik.r)/r and exp(-ik.r)/r only when r goes to infinity.
Of couse, the 1/r dependence of the asymptotic  fields becomes a 1/r^2 of poynting vector dependence  and describes the natural decay/ enhancement of outward/inward spherical waves from/to cone apex, and this factor will cancel with ds=r^2domega infinitesimal area element of a radial power flux calculation, where domega is a infinitesimal solid angle.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 01:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414709#msg1414709">Quote from: Ricvil on 08/10/2015 01:38 AM</a>
...
If one has a function with exponential format F=exp(k.x) and k is a constant then one can write k=(dF/dx)/F.

But if one has a function F=exp(k(x).x) then (dF/dx)/F=k(x) + xdk(x)/dx

If F has no exponential format is worse.

The wave solutions in spherical coodinates are the form  exp(+ik.r)/r and exp(-ik.r)/r only when r goes to infinity.
Yes, basically  γ = γ (r) hence it does not make sense that γ is treated as a constant to define

E = A e - γ r

γ = - (1/E) dE/dr = α + j β

because this is only true for γ = constant

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 02:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414715#msg1414715">Quote from: Rodal on 08/10/2015 01:57 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414709#msg1414709">Quote from: Ricvil on 08/10/2015 01:38 AM</a>
...
If one has a function with exponential format F=exp(k.x) and k is a constant then one can write k=(dF/dx)/F.

But if one has a function F=exp(k(x).x) then (dF/dx)/F=k(x) + xdk(x)/dx

If F has no exponential format is worse.

The wave solutions in spherical coodinates are the form  exp(+ik.r)/r and exp(-ik.r)/r only when r goes to infinity.
Yes, basically  γ = γ (r) hence it does not make sense that γ is treated as a constant to define

E = A e - γ r

γ = - (1/E) dE/dr = α + j β

because this is only true for γ = constant

So, really

-  (1/E) dE/dr  = γ + r dγ/dr

So Zeng and Fan's expression is exact when dγ/dr = 0, that is when γ is  constant.

and approximate for dγ/dr  ~ 0 (γ nearly constant)

so in the images shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414705#msg1414705 above and in Zeng and Fan's figures, the γ expression is more accurate as a measure of attenuation where γ is flat (where the gradient dγ/dr  ~ 0 ) and nearly constant, which is more nearly the case for values such that:

γ = 0  (NO ATTENUATION)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/10/2015 02:32 AM
I took a break today and let my computer run 64 cycles of the Shell conic frustum cavity model. The png views and csv data of the final 14 time slices is available here. To me, it does look to be much more "converged" than 32 cycle runs.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)

Please read the data description file for the details of the run.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/10/2015 02:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414718#msg1414718">Quote from: Rodal on 08/10/2015 02:09 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414715#msg1414715">Quote from: Rodal on 08/10/2015 01:57 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414709#msg1414709">Quote from: Ricvil on 08/10/2015 01:38 AM</a>
...
If one has a function with exponential format F=exp(k.x) and k is a constant then one can write k=(dF/dx)/F.

But if one has a function F=exp(k(x).x) then (dF/dx)/F=k(x) + xdk(x)/dx

If F has no exponential format is worse.

The wave solutions in spherical coodinates are the form  exp(+ik.r)/r and exp(-ik.r)/r only when r goes to infinity.
Yes, basically  γ = γ (r) hence it does not make sense that γ is treated as a constant to define

E = A e - γ r

γ = - (1/E) dE/dr = α + j β

because this is only true for γ = constant

So, really

-  (1/E) dE/dr  = γ + r dγ/dr

So Zeng and Fan's expression is exact when dγ/dr = 0, that is when γ is  constant.

and approximate for dγ/dr  ~ 0 (γ nearly constant)

so in the images shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414705#msg1414705 above and in Zeng and Fan's figures, the γ expression is more accurate as a measure of attenuation where γ is flat (where the gradient dγ/dr  ~ 0 ) and nearly constant, which is more nearly the case for values such that:

γ = 0  (NO ATTENUATION)

Gamma = alfa (attenuation) + jbeta (propagation)
No attenuation = zero alfa

Be careful. The expression for gamma does not make sense for stationary waves ( a superposition of two counter propagating waves and, of course, with diferent gammas)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 02:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414721#msg1414721">Quote from: Ricvil on 08/10/2015 02:37 AM</a>
...
Gamma = alfa (attenuation) + jbeta (propagation)
No attenuation = zero alfa

Becareful. The expression for gamma do not make sense for stationary waves ( two counter propagating waves and, of course, with diferent gammas)
Yes I realize that.  There is no harm in showing it simply as -(1/E)dE/dr without the meaning attached by Zeng and Fan, to understand what -(1/E)dE/dr looks like.

-(1/E)dE/dr is only dependent on r since E is separated into multiplicative components of the three spherical coordinates

(1/E)dE/dr just means the gradient of the logarithmic of the electric field, since

-(1/E)dE/dr = - d(Log[E]/dr (no approximation here, this is a correct expression for the logarithmic gradient)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/10/2015 02:59 AM
Pedantically it's the gradient of the log of the field, rather than the log of the gradient
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 03:16 AM
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm
https://youtu.be/1rOvWi5QNZE
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 03:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414724#msg1414724">Quote from: deltaMass on 08/10/2015 02:59 AM</a>
Pedantically it's the gradient of the log of the field, rather than the log of the gradient

The term "logarithmic gradient" (not log of a gradient) has been employed in the Mathematics, Continuum Mechanics, Fluid Mechanics and Heat Transfer literature short for "the gradient of the log of the field"

http://bit.ly/1IDbv4a

because "logarithmic gradient" is less awkward and its precise meaning is given by the equation

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 03:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414728#msg1414728">Quote from: rfmwguy on 08/10/2015 03:16 AM</a>
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm

What's up with the Iron Cross on it ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 03:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414730#msg1414730">Quote from: Rodal on 08/10/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414728#msg1414728">Quote from: rfmwguy on 08/10/2015 03:16 AM</a>
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm

What's up with the Iron Cross on it ?
You've got me doc...not a company logo...decoration apparently.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 03:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414732#msg1414732">Quote from: rfmwguy on 08/10/2015 03:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414730#msg1414730">Quote from: Rodal on 08/10/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414728#msg1414728">Quote from: rfmwguy on 08/10/2015 03:16 AM</a>
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm

What's up with the Iron Cross on it ?
You've got me doc...not a company logo...decoration apparently.
and the inscription on it reading:

"Fear of the Lord"

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 03:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414734#msg1414734">Quote from: Rodal on 08/10/2015 03:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414732#msg1414732">Quote from: rfmwguy on 08/10/2015 03:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414730#msg1414730">Quote from: Rodal on 08/10/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414728#msg1414728">Quote from: rfmwguy on 08/10/2015 03:16 AM</a>
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm

What's up with the Iron Cross on it ?
You've got me doc...not a company logo...decoration apparently.
and the inscription on it reading:

"Fear of the Lord"
Thks, my italian is lame. strange thing to put on something someone wants to solicit funding for. Guess they're religious minded...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/10/2015 04:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414734#msg1414734">Quote from: Rodal on 08/10/2015 03:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414732#msg1414732">Quote from: rfmwguy on 08/10/2015 03:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414730#msg1414730">Quote from: Rodal on 08/10/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414728#msg1414728">Quote from: rfmwguy on 08/10/2015 03:16 AM</a>
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm

What's up with the Iron Cross on it ?
You've got me doc...not a company logo...decoration apparently.
and the inscription on it reading:

"Fear of the Lord"

The symbol is a "Cross Pattee" often associated with the Knights Templar. The Iron Cross has a different shape. See:  https://en.m.wikipedia.org/wiki/Cross_pattée

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/10/2015 04:44 AM
GrailShip, then.

You probably already realised that "Ni" is the first two letters of "inertia", reversed.  8) 8) 8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/10/2015 04:49 AM

Grail Ship indeed.  From: https://neolegesmotus.wordpress.com/2015/08/04/aspss-electromagnetic-engine-tds-vf2/
Quote
Last but not least, when functioning PNN-E produces massive E.M radiation, so who works in proximity of the prototype must wear a protective suit. Laureti found a curious but effective solution: he modified a medieval chain mail to work as a Faraday cage.

Wonder if he wore a Templar white tunic over the chain mail? :)

If he had a sword then it would be very easy for him to "cut the power!" :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: garrybinder on 08/10/2015 07:03 AM
I just realized that my thinking has been a bit off.  Seeing those things mounted to the back of a ship was interesting but not necessary.  Theoretically it isn't necessary that the frustum be in a vacuum at all (certainly useful in the analysis phase).  If it works best with air in it, then mount it in a canister with air.  If nitrogen, helium, xenon or even water vapor is best then that is what it runs in.  Which got me thinking, for the upcoming tests a measurement of the relative humidity would be very interesting given the interaction between microwaves and water molecules.  Back to bed...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/10/2015 07:21 AM
Has anyone, in the thousands of posts here, calculated how much water (gm/s) it would take to generate X N of thrust by evaporation and steam jetting?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/10/2015 07:33 AM

Quote
Seems like a similar scenario to SPR, though the design is different. Italian non Newtonian propulsion company. Hmmmmm

It looks cool, but the video is...unimpressive.

And while I can't quite put my finger on it, the basic concept seems flawed.  Maybe it would work for a ground effect device, say some sort of hovercraft?

Also, I note that like Shawyer, this guy immediately ventures into 'flying car' territory on rather lackluster experimental evidence. 

I mean, using David Bae's work as a sort of rough measure, I can almost buy a weird fluke or loophole that would permit propellentless thrust for a sustained period on the order of a few Newton's, but more than that...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/10/2015 07:44 AM
Has the article "Resonant cavities and space-time thrust" from Marco Frasca been discussed on this forum ? A quick search on "frasca" keyword gave no result.

This article, dated May 20, 2015, analyses, by solving Einstein field equations, the geometry of space-time in a cavity when a plane electromagnetic wave is present. Influence of cavity shape is also considered.

It looks a pretty serious work ... but I am not operational enough in General Relativity to make a deep referee of it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/10/2015 08:21 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414755#msg1414755">Quote from: Mezzenile on 08/10/2015 07:44 AM</a>
Has the article "Resonant cavities and space-time thrust" from Marco Frasca been discussed on this forum ? A quick search on "frasca" keyword gave no result.

This article, dated May 20, 2015, analyses, by solving Einstein field equations, the geometry of space-time in a cavity when a plane electromagnetic wave is present. Influence of cavity shape is also considered.

It looks a pretty serious work ... but I am not operational enough in General Relativity to make a deep referee of it.

http://forum.nasaspaceflight.com/index.php?topic=37642.msg1378648#msg1378648

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/10/2015 09:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414690#msg1414690">Quote from: deltaMass on 08/09/2015 10:07 PM</a>
I can understand the attraction of taking the idea of Casimir friction in order to explain an EmDrive as some sort of Zero-Point Dean Drive. A pawl and ratchet into spacetime. What I don't understand is how people can make such a proposal when there is no Casimir effect in an EmDrive in the first place.

Sure there is. It is very easy to justify in a type 2* EmDrive, as the gap between the dielectric insert **and small end plate. For a type 3 this geometry is satisfied by the close proximity of air molecules to the copper walls.

Linked to is a study using CO2 and CH4 molecules which illustrates this.
http://arxiv.org/abs/1506.01673

My attempts to study Casimir friction are related to the type 3 cavity, even though it applies equally to a type 2. All the info I dug up throughout threads 1 and 2 were related to the dielectric insert in a type 2 cavity and were geared toward the Casimir momentum phenomena.

*Emdrive types in image at bottom.
Type 1: Cavity with dielectric insert
Type 2: Tapered cavity with dielectric insert
Type 3: Tapered cavity with no dielectric insert

A side note, there is no way to justify a copper or aluminum cavity that is "dielectric free". The oxides of both are dielectrics, as is the air.

**Star-Drive reported interesting thrust reversal effects in thread 2, when a bolt holding the dielectric down melted and came loose.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1335190#msg1335190
I know from studying Casimir geometry that, Casimir energy can be switched from negative to positive simply by disturbing the geometry. For example, corners are positive, while parallel plates are negative.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/10/2015 09:21 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414760#msg1414760">Quote from: TheTraveller on 08/10/2015 08:21 AM</a>
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1378648#msg1378648

Thank you for the link. So Marco Fresca is still working to improve his paper and will publish it on arxiv when ready with numerical results on the predicted thrust (apparently this day is not yet arrived).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/10/2015 09:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414741#msg1414741">Quote from: demofsky on 08/10/2015 04:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414734#msg1414734">Quote from: Rodal on 08/10/2015 03:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414732#msg1414732">Quote from: rfmwguy on 08/10/2015 03:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414730#msg1414730">Quote from: Rodal on 08/10/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414728#msg1414728">Quote from: rfmwguy on 08/10/2015 03:16 AM</a>
Interesting reddit link... https://neolegesmotus.wordpress.com

Seems like a similar senario to spr, tho design is different. Italian non newtonian propulsion company. Hmmmmm

What's up with the Iron Cross on it ?
You've got me doc...not a company logo...decoration apparently.
and the inscription on it reading:

"Fear of the Lord"

The symbol is a "Cross Pattee" often associated with the Knights Templar. The Iron Cross has a different shape. See:  https://en.m.wikipedia.org/wiki/Cross_pattée

Reminds me of the early Crookes tubes experiments with "Maltese cross" mask :
(340px-Kat%C3%B3dsugarak_m%C3%A1gneses_mez%C5%91ben%282%29.jpg)

Last but not least, when functioning PNN-E produces massive E.M radiation, so who works in proximity of the prototype must wear a protective suit. Laureti found a curious but effective solution: he modified a medieval chain mail to work as a Faraday cage.

Space knights... their hopes make other propellentless propulsion claims pale in comparison :

Quote
However, while testing PNN-E and in particular TDS VF2, ASPS discovered that the thruster doesn’t follow the common law of inertia, because E.M propulsion literally “accelerates on its own acceleration”. Hence there is the need for ASPS to define a totally new law of inertia that would allow an E.M starship to cover several light years in few seconds! It sounds astonishing but ASPS seems confident in theory effectiveness.

  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: qraal on 08/10/2015 11:19 AM
Frobnicat, that smiley was perfect. Definitely a WTF moment.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/10/2015 11:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414769#msg1414769">Quote from: Mezzenile on 08/10/2015 09:21 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414760#msg1414760">Quote from: TheTraveller on 08/10/2015 08:21 AM</a>
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1378648#msg1378648

Thank you for the link. So Marco Fresca is still working to improve his paper and will publish it on arxiv when ready with numerical results on the predicted thrust (apparently this day is not yet arrived).

The author is a NSF member named StrongGR:
http://forum.nasaspaceflight.com/index.php?action=profile;u=47907

Maybe try PMing him for more info?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 11:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414769#msg1414769">Quote from: Mezzenile on 08/10/2015 09:21 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414760#msg1414760">Quote from: TheTraveller on 08/10/2015 08:21 AM</a>
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1378648#msg1378648

Thank you for the link.
So Marco Fresca is still working to improve his paper and will publish it on arxiv when ready with numerical results on the predicted thrust (apparently this day is not yet arrived).
No, the message linked by TheTraveller is just an old message, one of several messages posted by the author.
Marco's (Frasca -not "Fresca"-  ;)   ) paper has already been published in ResearchGate some time ago.  We discussed Marco's paper in detail with him prior to publication.  We discussed limits of expressions, the perturbation approach and numerical results.  The conclusion was that General Relativity could not be used to justify the claimed thrust for the EM Drive because the GR effect discussed by Frasca happens very close to the singularity at the vertex of the cone (as it is evident from his paper).  Shawyer by intentional design on his part (claiming a waveguide cut-off effect on the small diameter although there is no such cut-off for tapered waveguides) stopped the EM Drive geometry very far away from the vertex of the cone, hence the effect discussed by Frasca is several orders of magnitude much smaller that what is claimed as thrust by EM Drive researchers.   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 01:09 PM
Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.

So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.

Onward and upward - Dave (rfmwguy)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 01:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414800#msg1414800">Quote from: rfmwguy on 08/10/2015 01:09 PM</a>
Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.

So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.

Onward and upward - Dave (rfmwguy)

Happy Birthday :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/10/2015 01:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414793#msg1414793">Quote from: Rodal on 08/10/2015 11:47 AM</a>
No, the message linked by TheTraveller is just an old message, one of several messages posted by the author.
Marco's paper has already been published in Arxiv and ResearchGate some time ago.  We discussed Marco's paper in detail with him prior to publication.  We discussed limits of expressions, the perturbation approach and numerical results.  The conclusion was that General Relativity could not be used to justify the claimed thrust for the EM Drive because the GR effect discussed by Frasca happens very close to the singularity at the vertex of the cone (as it is evident from his paper).  Shawyer by intentional design on his part (claiming a waveguide cut-off effect on the small diameter although there is no such cut-off for tapered waveguides) stopped the EM Drive geometry very far away from the vertex of the cone, hence the effect discussed by Frasca is several orders of magnitude much smaller that what is claimed as thrust by EM Drive researchers.

Ok, I have found the final article at ResearchGate (apparently it is not in Arxiv). Effectively the predicted thrust of 6*10^-22 N is realy too small to be a candidate explanation to the fantastic EMDrive test results.
By the way it is interresting to learn that Electromagnetic plane wave and Gravitational plane wave produce the same gravitational attractions on test particles (they dont need to have an electrical charge).




Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 01:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414785#msg1414785">Quote from: qraal on 08/10/2015 11:19 AM</a>
Frobnicat, that smiley was perfect. Definitely a WTF moment.
LOL...yep  :o was perfect. Funny how people jump to extreme applications without due-diligence on prototypes...i.e. replication, explanation and 3rd party verification. That leads to speculation on whether its all a funding scheme.

On NSF-1701, if I've detected any force whatsoever, I'll try and figure out why only to a point. After that, I would prefer to offer it (for free) to a reputable institution that is willing to duplicate tests under (expensive) laboratory conditions.

Of course, if they break it...that would spoil my day ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/10/2015 01:44 PM
I was asking myself how long it would take to empty the frustum of the energy stored, now I know, not long  :)

Extracting microwave energy from a cavity by mode conversion at a coupling window

http://rd.springer.com/article/10.1134/1.1259080

"It is shown that microwave rf pulse compressors with copper storage cavities and energy extraction by mode conversion at a coupling window can provide gains of 5–13 dB with output signal durations of 20–150 ns and peak powers of 5–10 MW in the 3-cm band and 50–100 MW in the 10-cm band. "
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/10/2015 01:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414800#msg1414800">Quote from: rfmwguy on 08/10/2015 01:09 PM</a>
Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.

So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.

Onward and upward - Dave (rfmwguy)
And a very happy birthday from another of the older generation. As my mom said to me many times Dave. Make it so!
Michelle

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/10/2015 01:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414811#msg1414811">Quote from: OttO on 08/10/2015 01:44 PM</a>
I was asking myself how long it would take to empty the frustum of the energy stored, now I know, not long  :)

Extracting microwave energy from a cavity by mode conversion at a coupling window

http://rd.springer.com/article/10.1134/1.1259080

"It is shown that microwave rf pulse compressors with copper storage cavities and energy extraction by mode conversion at a coupling window can provide gains of 5–13 dB with output signal durations of 20–150 ns and peak powers of 5–10 MW in the 3-cm band and 50–100 MW in the 10-cm band. "
Perfect! Was looking this morning at how much the mode changes could kill off the Q and the time frame needed. Thanks

back to reading and lurking.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/10/2015 02:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414750#msg1414750">Quote from: deltaMass on 08/10/2015 07:21 AM</a>
Has anyone, in the thousands of posts here, calculated how much water (gm/s) it would take to generate X N of thrust by evaporation and steam jetting?

I can do it, but require more data.  It's F= (p_exit - p_0) A_e + _mdot V_e
The terms are, in order, pressure at the nozzle, ambient pressure, Area of the nozzle exit, Mass flow rate (in kilograms per second), and exit velocity.

For forces ~ 1 N in air I "feel" like...
A.) You would notice it.
B.) The cavity would exhaust the available water vapor in the cavity very rapidly.

For short bursts of power or muN force levels steam jetting or hot air jets do "feel" like realistic sources of experimental error.  Putting symmetrical (relatively) big holes in the sidewalls and doing longer runs should reduce these by maximizing Ae, minimizing p, and exhausting the available water vapor.

I have similar concerns with hot air in the cavity causing ballooning error.  I don't know how to eliminate that effect while retaining a gas-filled cavity.  Advice in that direction would be appreciated.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/10/2015 02:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414800#msg1414800">Quote from: rfmwguy on 08/10/2015 01:09 PM</a>
Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.

So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.

Onward and upward - Dave (rfmwguy)

Happy birthday, youngster.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/10/2015 02:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414374#msg1414374">Quote from: rfmwguy on 08/08/2015 01:08 PM</a>
Hi Thor,
No, 30% is the amount of time power is at 100%, so it will "pulse" at full power for 30% of the time.

Sorry, busy weekend!  Happy birthday!

Ok, right.  That's makes the spreadsheet spit out (assuming 64% efficiency in converting electrical input into RF) a figure of up to 100.93mN or 144.71 mN for 30% of the time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/10/2015 02:38 PM
Conical Waves Producing Longitudinal Power Flows
http://rd.springer.com/article/10.1134/1.1307823#page-1

"A conical electromagnetic wave converging to its axis is studied theoretically. It is
demonstrated that the wave produces an intense self-accelerating flow of energy
(momentum)"


Seem to me a bit strange but... [EDIT] Do not stay in front, very barsoonian  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 02:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414841#msg1414841">Quote from: tleach on 08/10/2015 02:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414374#msg1414374">Quote from: rfmwguy on 08/08/2015 01:08 PM</a>
Hi Thor,
No, 30% is the amount of time power is at 100%, so it will "pulse" at full power for 30% of the time.

Sorry, busy weekend!  Happy birthday!

Ok, right.  That's makes the spreadsheet spit out (assuming 64% efficiency in converting electrical input into RF) a figure of up to 100.93mN or 144.71 mN for 30% of the time.

Please notice that McCulloch's formula is completely unable to distinguish between TM (transverse magnetic) from TE (transverse electric) modes.  Actually McCulloch's formula completely ignores the mode shape (it ignores not only whether TE or TM but also it ignores the quantum mode shape numbers m,n,p).  This is a weakness in McCulloch's formula (not present in Notsosureofit's formula that does take into account the mode shapes).

Those claiming much larger thrust and thrust/InputPower claim to use TE modes: Shawyer and Yang.
NASA also reported much larger thrust/InputPower when using TE modes but could not excite it consistently so they switched to TM modes.

So, there is considerable uncertainty when predicting thrust with a formula that ignores the mode shape of EM Drive operation.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/10/2015 02:54 PM

Nice work aero. I like this and your run file is very easy to read.

I organized the images in a equal grid 0S3xpKH.jpg
My question is, are the vertical columns when arranged like this showing the same time stamp through the frustum for the sample on the waveform showing the mode?

Shell
First column
ex.t00
ey.t00
ez.000
etc....

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414720#msg1414720">Quote from: aero on 08/10/2015 02:32 AM</a>
I took a break today and let my computer run 64 cycles of the Shell conic frustum cavity model. The png views and csv data of the final 14 time slices is available here. To me, it does look to be much more "converged" than 32 cycle runs.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)

Please read the data description file for the details of the run.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/10/2015 03:16 PM

Thanks.
Yes, all of the slices labelled t 00 are taken just after the 62.7th cycle, those labelled t 01 just after the 62.8th cycle  and so forth, up to the slice labelled t13 which is taken at the end of the run, at the 64th cycle.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414863#msg1414863">Quote from: SeeShells on 08/10/2015 02:54 PM</a>
Nice work aero. I like this and your run file is very easy to read.

I organized the images in a equal grid 0S3xpKH.jpg
My question is, are the vertical columns when arranged like this showing the same time stamp through the frustum for the sample on the waveform showing the mode?

Shell
First column
ex.t00
ey.t00
ez.000
etc....

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414720#msg1414720">Quote from: aero on 08/10/2015 02:32 AM</a>
I took a break today and let my computer run 64 cycles of the Shell conic frustum cavity model. The png views and csv data of the final 14 time slices is available here. To me, it does look to be much more "converged" than 32 cycle runs.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)

Please read the data description file for the details of the run.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/10/2015 03:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414849#msg1414849">Quote from: Rodal on 08/10/2015 02:40 PM</a>
Please notice that McCulloch's formula is completely unable to distinguish between TM (transverse magnetic) from TE (transverse electric) modes.  Actually McCulloch's formula completely ignores the mode shape (it ignores not only whether TE or TM but also it ignores the quantum mode shape numbers m,n,p).  This is a weakness in McCulloch's formula (not present in Notsosureofit's formula that does take into account the mode shapes).

Those claiming much larger thrust and thrust/InputPower claim to use TE modes: Shawyer and Yang.
NASA also reported much larger thrust/InputPower when using TE modes but could not excite it consistently so they switched to TM modes.

So, there is considerable uncertainty when predicting thrust with a formula that ignores the mode shape of EM Drive operation.

The derivation (F = 6PQL/c * [1/(L+4wb) - 1/(L+4ws) ] which I found on http://physicsfromtheedge.blogspot.co.uk/2015/02/mihsc-vs-emdrive-data-3d.html) that I'm using in my spreadsheet doesn't take into account the input frequency of the radiation either, just the Power and the "Q".

EDIT:  If I get a chance tonight I'll try to add Notsosureofit's formula to my spreadsheet and see what happens

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/10/2015 04:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414807#msg1414807">Quote from: rfmwguy on 08/10/2015 01:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414785#msg1414785">Quote from: qraal on 08/10/2015 11:19 AM</a>
Frobnicat, that smiley was perfect. Definitely a WTF moment.
LOL...yep  :o was perfect. Funny how people jump to extreme applications without due-diligence on prototypes...i.e. replication, explanation and 3rd party verification. That leads to speculation on whether its all a funding scheme.

On NSF-1701, if I've detected any force whatsoever, I'll try and figure out why only to a point. After that, I would prefer to offer it (for free) to a reputable institution that is willing to duplicate tests under (expensive) laboratory conditions.

Of course, if they break it...that would spoil my day ;)

Is it legally possible and ethically right for us to try and open source this Resonant Cavity Thruster? I mean seriously, nobody owns the wheel. If this approach proves to be a viable means for propellantless propulsion, then the impact factor is no less important.

For Shawyer to try and patent this before there was even a dream of a viable commercial product is ludicrous.

He should have opened it up to research at the beginning.

Based on what I know, the current iteration is obviously not viable.

So, what do we have now that is truly unique and novel with which we can package up and give to the world?

If members of the public are able to own a personal stake in something as evolutionary as this, some will gladly invest enormous amounts of effort, even with no guarantee of any financial reward or any success; like us.

So can it be done? Should it be done? If so, we need help...

We just have to make it roll. The rest is history.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 04:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414883#msg1414883">Quote from: tleach on 08/10/2015 03:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414849#msg1414849">Quote from: Rodal on 08/10/2015 02:40 PM</a>
Please notice that McCulloch's formula is completely unable to distinguish between TM (transverse magnetic) from TE (transverse electric) modes.  Actually McCulloch's formula completely ignores the mode shape (it ignores not only whether TE or TM but also it ignores the quantum mode shape numbers m,n,p).  This is a weakness in McCulloch's formula (not present in Notsosureofit's formula that does take into account the mode shapes).

Those claiming much larger thrust and thrust/InputPower claim to use TE modes: Shawyer and Yang.
NASA also reported much larger thrust/InputPower when using TE modes but could not excite it consistently so they switched to TM modes.

So, there is considerable uncertainty when predicting thrust with a formula that ignores the mode shape of EM Drive operation.

The derivation (F = 6PQL/c * [1/(L+4wb) - 1/(L+4ws) ] which I found on http://physicsfromtheedge.blogspot.co.uk/2015/02/mihsc-vs-emdrive-data-3d.html) that I'm using in my spreadsheet doesn't take into account the input frequency of the radiation either, just the Power and the "Q".

EDIT:  If I get a chance tonight I'll try to add Notsosureofit's formula to my spreadsheet and see what happens

Of course there are many ways to look at this, to play devil's advocate:

1) It may be that Shawyer's and Yang's claims are unreliable and the only reliable claims are those of NASA using TM modes

2) Since so little is known with certainty at this point in time, the simplicity of McCulloch's formula at this stage may be justified, as there is no point in overfitting unreliable data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: phaseshift on 08/10/2015 04:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414622#msg1414622">Quote from: TheTraveller on 08/09/2015 04:11 PM</a>
Interesting Russian EMDrive like patent:
http://bankpatentov.ru/node/123593

and comment received on Reddit EMDrive forum:
https://www.reddit.com/r/EmDrive/comments/3ceyjv/email_from_roger_shawyer/ctww6rd

As Dr. Vladimir Leonov claims the "Shawyer Effect" works via the QV, Dr. White might be interested.

Thanks for posting this TT.  Warping space is a requirement of the EM-Drive and as the author states it can be done through an EM interaction. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 05:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414800#msg1414800">Quote from: rfmwguy on 08/10/2015 01:09 PM</a>
Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.

So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.

Onward and upward - Dave (rfmwguy)

Just think of it, Dave: Donald Trump is over 69 years old, so you have more than 9 years left for you to run for President of the US  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 08/10/2015 06:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414968#msg1414968">Quote from: Rodal on 08/10/2015 05:53 PM</a>
Just think of it, Dave: Donald Trump is over 69 years old, so you have more than 9 years left for you to run for President of the US  :)

13 years if you wait as long as Bernie Sanders did.  ;D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/10/2015 06:11 PM
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing

I took both Center x and Center Y pages and opened them into separate folders, sized them so one row was 14 images across and the vertical columns were synced 00, 01, 02, 03, 04... same time slice. Then switched back and forth between the pages comparing a image and mode for X to Y and at the same position.

In some cases the modes match X and Y but several they don't even come close. Just another flag of an interesting anomaly of how you could see in a relatively symmetrical cavity mode variation just between a X slice through the middle and a Y slice through the middle in the same time stamp.

Or has everyone seen this weirdness and you're going to go... phhhsst, silly old woman... 

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 06:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414982#msg1414982">Quote from: SeeShells on 08/10/2015 06:11 PM</a>
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing

I took both Center x and Center Y pages and opened them into separate folders, sized them so one row was 14 images across and the vertical columns were synced 00, 01, 02, 03, 04... same time slice. Then switched back and forth between the pages comparing a image and mode for X to Y and at the same position.

In some cases the modes match X and Y but several they don't even come close. Just another flag of an interesting anomaly of how you could see in a relatively symmetrical cavity mode variation just between a X slice through the middle and a Y slice through the middle in the same time stamp.

Or has everyone seen this weirdness and you're going to go... phhhsst, silly old woman... 

Shell
Since the mode shapes are shown on different scales, without showing the numbers,  a mode shape that has magnitude that is dozens or hundreds of times smaller amplitude (and thus insignficant) looks significant when compared without numbers.  Hence the images are very difficult to understand .

Remember how we progressed:

1) At the beginning of MEEP runs, the same fields were shown on different scales from time step to time step.  It looked so crazy that even the field outside the EM Drive had flashing colors.  And inside the EM Drive we could see fractals that were numerical artifacts.

This was fixed by showing all the time steps at the same final scale.  This fixed the fractals and the crazy colors outside the EM Drive.

2) We still have the problem that different fields in different directions: Ex, Ey, Ez, Hx, Hy, and Hz, are shown with different scales.  Thus one is not able to distinguish, say if E in the x direction is 1000 times less than E in the y direction.  Thus we cannot distinguish "noise" from signal.

ALL electric fields should be shown on the same scale and all magnetic fields should be shown to the same scale.  Otherwise there is no comprehension.

3) I cannot tell what the mode shape being excited is, from looking at these images: is it TE ? is it TM? nobody knows.  Why is it that nobody knows? Because the fields are not shown to the same scale, thus nobody can tell whether it is TE or TM.  We don't know what is noise and what is signal. 

Is the field in the longitudinal z direction an electric field (and hence a TM mode) or is it a magnetic field (and thus a TE mode).  We cannot tell, both mode shapes are being shown and we don't know which is large and which is negligible.

If they would be shown to the same scale, and one mode shape happens to be 100 times smaller magnitude than another one, it would look like zero, and we would not look at it, thus we would better understand because we would be looking ONLY at the mode shapes that are high in magnitude.  The way it is now, we don't know what is high magnitude and what is low magnitude. 

Imagine what life would be like if your senses would be such that we would not be able to distinguish between what is near and what is far, between what is high and what is low, we would be lost.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/10/2015 06:53 PM
Happy birthday rfmwguy  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 07:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415009#msg1415009">Quote from: X_RaY on 08/10/2015 06:53 PM</a>
Happy birthday rfmwguy  :)
Danke, herr x_ray!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 07:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414968#msg1414968">Quote from: Rodal on 08/10/2015 05:53 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414800#msg1414800">Quote from: rfmwguy on 08/10/2015 01:09 PM</a>
Off topic alert - Today, I turned the big six-zero; a milestone birthday. Which should be used to convince others that one can still think, dream and build well into their senior era. So many companies and institutions look to replace older folks once they turn 50...I know from experience. I also know that its a waste of talent to do this.

So, here's to the older generation still plugging away at science. How I wish something like this project were around when I was much younger. THAT should be a message to the young folks out there to get involved in science early. Push the envelope, think outside the box, do something different...who knows, what you may come up with could change the world.

Onward and upward - Dave (rfmwguy)

Just think of it, Dave: Donald Trump is over 69 years old, so you have more than 9 years left for you to run for President of the US  :)
Thanks, Doc...you cheered me up enough that I feel like this ;)
albert-einstein-ad.jpg

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/10/2015 07:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415021#msg1415021">Quote from: rfmwguy on 08/10/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415009#msg1415009">Quote from: X_RaY on 08/10/2015 06:53 PM</a>
Happy birthday rfmwguy  :)
Danke, herr x_ray!

Is it possible to record your next live run?
I have little problems with the time difference between our countries, last time i was sleeping, dont see your live show   :-[

Did you see this file?
There is a description for possible Q measurement with only one port.
The problem with a magnetron is that is only a source, there is no IQ mixer (or six port) inside the magnetron... So it may be the simplest way is to use a probe port in that case.

http://uspas.fnal.gov/materials/09UNM/ResonantCavities.pdf (big file be patient)
Thanks Mulletron for post the link

BTW: I hope you got a great party today! :P

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 07:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415032#msg1415032">Quote from: X_RaY on 08/10/2015 07:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415021#msg1415021">Quote from: rfmwguy on 08/10/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415009#msg1415009">Quote from: X_RaY on 08/10/2015 06:53 PM</a>
Happy birthday rfmwguy  :)
Danke, herr x_ray!

Is it possible to record your next live run?
I have little problems with the time difference between our countries, last time i was sleeping, dont see your live show   :-[

Did you see this file?
There is a description for possible Q measurement with only one port.
The problem with a magnetron is that is only a source, there is no IQ mixer (or six port) inside the magnetron... So it may be the simplest way is to use a probe port in that case.

http://uspas.fnal.gov/materials/09UNM/ResonantCavities.pdf (big file be patient)
Thanks Mulletron for post the link

BTW: I hope you got a great party today! :P
I will have a live session the day before I run the actual live test, basically walking throught the setup. This should be 2 weeks or less and hope to announce it next week sometime.

Last thing I need to to get the Galinstan for the liquid metal power connectors.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/10/2015 07:39 PM
@rfmwguy: Happy Birthday!

About that spendy Galinstan: did you at least consider a fully-self-contained rig using batteries? - and what put you off it?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/10/2015 07:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415046#msg1415046">Quote from: deltaMass on 08/10/2015 07:39 PM</a>
@rfmwguy: Happy Birthday!

About that spendy Galinstan: did you at least consider a fully-self-contained rig using batteries? - and what put you off it?
Thks dm...I was going to use battery until the junk exciter spoiled my day. It was only going to put out about 8 watts after amplification...far too low power for me to be able to measure on the Floobie Stick balance beam...so, the magnetron was chosen.

I agree, batteries would have been best, but 4kV bias?...uhhh maybe not so much.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/10/2015 07:56 PM
Yeah, the inverter is the tricky bit. But...
http://powersupply33.com/converter-9v-to-13-5kv.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/10/2015 08:06 PM
I was thinking about the air ballooning effect... again ::)
And yes i am sure that was already discussed several times. ;)
It is cause by the higher kinetic energy of the particles, they need more space and generate a pressure at the surrounded walls...
I think that effect is only true for a cavity that allow to escape the gas while heating. If it is airtight the number of gas molecules per volume stays constant.
But than there is more energy inside the cavity and based on the restmass+velocity of the gas particles the system will be a little bit heavier the higher the temperature is in contrast to the surrounding.

The gas around the cavity also heats up, that causes a upstream of air.

The last effect is already true for rfmwguy and SheShells

This can be eliminated by testing the cone in the "up" and "down" direction.
In the horizontal direction using perforated copper a force based on this effect would always working forward the small diameter(inner sidewall) same would act at the lower outside wall but forward the big end, so it cancels each other...


Is there some argument i miss in my memory?
(only for my brain protocol...)


https://www.youtube.com/watch?v=PvZoSugrz24

https://en.wikipedia.org/wiki/Schlieren_imaging
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/10/2015 08:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414913#msg1414913">Quote from: Mulletron on 08/10/2015 04:21 PM</a>
For Shawyer to try and patent this before there was even a dream of a viable commercial product is ludicrous.

I vigorously disagree.  Mr. Shawyer has, hypothetically, discovered something that we thought was impossible. As such, in addition to his Nobel prize, he is fully entitled to own that intellectual property for the full duration of the patent and take full financial advantage of it. His right to make a billion dollars on this is just as real as your right to make a billion dollars on any improvements you make to it.

A patent is a reward and incentive for the inventor's investment of effort, risk, failures, money, time, and life in creating a device or idea. If they choose to open source it or freely license it then that is their choice. They are under no ethical or moral obligation to do so.

Quote
He should have opened it up to research at the beginning.
He did.  He's been writing about it publicly for a decade to anyone who would listen.  For his trouble he's been called a fraud and charlatan.  He's been mocked and ridiculed.  To imply that he's hoarded this to himself is a particularly bitter insult.

Quote
Based on what I know, the current iteration is obviously not viable.
Your knowledge is incorrect.  He discovered the Shawyer effect and then spent years inventing, experimenting, and refining devices that generated thrust from RF energy.  The device accomplished the "impossible".  That certainly seems "viable" to me.

Quote
If members of the public are able to own a personal stake in something as evolutionary as this, some will gladly invest enormous amounts of effort, even with no guarantee of any financial reward or any success; like us.
Mr. Shawyer built this technology "with no guarantee of any financial reward or any success."  How is his contribution somehow inferior to what we would create?

Quote
So can it be done? Should it be done? If so, we need help...
We just have to make it roll. The rest is history.

Patent law is not simple at all.  Even worse, it varies wildly by country and it changes over time.  In the US, there is a tiny window for building a copy of a device to determine the accuracy of the specification, for the sole purpose of gratifying a philosophical taste, or curiosity, or for mere amusement.  I currently work within those exceptions.  Any use beyond that should be negotiated with Mr. Shawyer.

-eag

P.s. ... don't forget that Cannae has patents on this kit too.  Even though their drive !did not work! they still own part of the IP.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/10/2015 09:00 PM
I call it "ballooning" when the cavity is perfectly airtight and the walls bulge slightly - the thinner the walls, the greater this effect. Due to the increase in external volume at constant contained mass, the cavity density decreases and thus experiences increased buoyancy in air. There is however a counter-effect present; because the air around the cavity is also heated, it enjoys a lower density, which in turn reduces this buoyancy. Which of these two competing effects wins out depends on all the details.

When the cavity is not airtight, there are two effects to be expected:
a) a loss of all-up cavity mass due to the mass of the expelled air with increased heating
b) the possibility of a rocket effect due to convection of cavity gas in a preferred direction, which in turn depends on where it's leaking. Note that, for certain leakage patterns, one would see the artifact of reversed thrust when the cavity is flipped, since now the "jet" direction is also flipped.

Note that, in vacuum, none of the above occur if care is taken to evacuate the cavity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/10/2015 09:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415079#msg1415079">Quote from: deltaMass on 08/10/2015 09:00 PM</a>
I call it "ballooning" when the cavity is perfectly airtight and the walls bulge slightly - the thinner the walls, the greater this effect. Due to the increase in external volume at constant contained mass, the cavity density decreases and thus experiences increased buoyancy in air. There is however a counter-effect present; because the air around the cavity is also heated, it enjoys a lower density, which in turn reduces this buoyancy. Which of these two competing effects wins out depends on all the details.

When the cavity is not airtight, there are two effects to be expected:
a) a loss of all-up cavity mass due to the mass of the expelled air with increased heating
b) the possibility of a rocket effect due to convection of cavity gas in a preferred direction, which in turn depends on where it's leaking. Note that, for certain leakage patterns, one would see the artifact of reversed thrust when the cavity is flipped, since now the "jet" direction is also flipped.

Note that, in vacuum, none of the above occur if care is taken to evacuate the cavity.
This thought was based on inelastic walls who are thick enough..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/10/2015 09:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415046#msg1415046">Quote from: deltaMass on 08/10/2015 07:39 PM</a>
@rfmwguy: Happy Birthday!

About that spendy Galinstan: did you at least consider a fully-self-contained rig using batteries? - and what put you off it?

You can buy a cheap UPS Pure-sine inverter relatively cheap, and use that to power the magnetron transformer.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/10/2015 09:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414995#msg1414995">Quote from: Rodal on 08/10/2015 06:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414982#msg1414982">Quote from: SeeShells on 08/10/2015 06:11 PM</a>
https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing

I took both Center x and Center Y pages and opened them into separate folders, sized them so one row was 14 images across and the vertical columns were synced 00, 01, 02, 03, 04... same time slice. Then switched back and forth between the pages comparing a image and mode for X to Y and at the same position.

In some cases the modes match X and Y but several they don't even come close. Just another flag of an interesting anomaly of how you could see in a relatively symmetrical cavity mode variation just between a X slice through the middle and a Y slice through the middle in the same time stamp.

Or has everyone seen this weirdness and you're going to go... phhhsst, silly old woman... 

Shell
Since the mode shapes are shown on different scales, without showing the numbers,  a mode shape that has magnitude that is dozens or hundreds of times smaller amplitude (and thus insignficant) looks significant when compared without numbers.  Hence the images are very difficult to understand .

Remember how we progressed:

1) At the beginning of MEEP runs, the same fields were shown on different scales from time step to time step.  It looked so crazy that even the field outside the EM Drive had flashing colors.  And inside the EM Drive we could see fractals that were numerical artifacts.

This was fixed by showing all the time steps at the same final scale.  This fixed the fractals and the crazy colors outside the EM Drive.

2) We still have the problem that different fields in different directions: Ex, Ey, Ez, Hx, Hy, and Hz, are shown with different scales.  Thus one is not able to distinguish, say if E in the x direction is 1000 times less than E in the y direction.  Thus we cannot distinguish "noise" from signal.

ALL electric fields should be shown on the same scale and all magnetic fields should be shown to the same scale.  Otherwise there is no comprehension.

3) I cannot tell what the mode shape being excited is, from looking at these images: is it TE ? is it TM? nobody knows.  Why is it that nobody knows? Because the fields are not shown to the same scale, thus nobody can tell whether it is TE or TM.  We don't know what is noise and what is signal. 

Is the field in the longitudinal z direction an electric field (and hence a TM mode) or is it a magnetic field (and thus a TE mode).  We cannot tell, both mode shapes are being shown and we don't know which is large and which is negligible.

If they would be shown to the same scale, and one mode shape happens to be 100 times smaller magnitude than another one, it would look like zero, and we would not look at it, thus we would better understand because we would be looking ONLY at the mode shapes that are high in magnitude.  The way it is now, we don't know what is high magnitude and what is low magnitude. 

Imagine what life would be like if your senses would be such that we would not be able to distinguish between what is near and what is far, between what is high and what is low, we would be lost.

Sigh. Lost? No, just regroup.
Thanks for the recap, I did't realize we handicapped the visual data as much as we did in truncating data simply making it unusable as a visual aid.

I hope the numbers haven't been truncated in the CSV files as well. Back to lurk and dig.

Shell

 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 09:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415083#msg1415083">Quote from: SeeShells on 08/10/2015 09:21 PM</a>
...

Sigh. Lost? No, just regroup.
Thanks for the recap, I did't realize we handicapped the visual data as much as we did in truncating data simply making it unusable as a visual aid.

I hope the numbers haven't been truncated in the CSV files as well. Back to lurk and dig.

Shell
The numbers are in the csv files, but it is much more time consuming to post-process the csv files than to just click and look at the images.  All my 3 computers are otherwise occupied at the moment.  I had a small window of time in one computer which I used to calculate something that Todd will be interested in :)  Hope to get to this soon.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 09:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414705#msg1414705">Quote from: Rodal on 08/10/2015 01:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414698#msg1414698">Quote from: WarpTech on 08/09/2015 11:58 PM</a>
...
Agreed, they misuse the word "constant" when pertaining to the variables, alpha and beta. It is a terminology issue though, not math that is incorrect.

It is not magic. Equation 12 is the derivative of equation 2, per equations 9 and 10, for TE modes. Equations 13 and 14 are the derivatives of equation 5, for TM modes. Since there is no component of Er in equation 2, there is no radial component of attenuation for the E field in the r direction. But there is for the TM mode, in equation 5 to give equation 14.

Todd

It may be interesting to plot the γ function, the logarithmic gradient of the electric field:

γ = - dLog[E]/dr = - (1/E)*dE/dr

defined by Zeng and Fan, and apply it to the case of standing waves in a closed resonant cavity: Yang/Shell for TE011 and TE012, to see what it looks like.

In this case γ = γθ = γφ

γθ = - (1/Eθ)*dEθ/dr = γφ = - (1/Eφ)*dEφ/dr

γ is real, these are standing waves hence there is no imaginary component of γ.

γ grows without bounds, to Infinity, at each end because the transverse electric fields are zero at the big base and at the small base in order to satisfy the boundary condition that electric fields parallel to a metal boundary must be zero.  Since γ is defined as the ratio of the gradient of the electric field with respect to r, divided by the electric field, when the field is zero at the bases, while the numerator is maximum, γ is infinite at the boundaries.

For TE012, γ also grows without bounds at the middle node of the two half-wave patterns because at that point the transverse electric field is zero while its gradient with respect to r is maximum.

Notice that γ is negative at the small base (small r) and positive at the big base (large r).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414718#msg1414718">Quote from: Rodal on 08/10/2015 02:09 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414715#msg1414715">Quote from: Rodal on 08/10/2015 01:57 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414709#msg1414709">Quote from: Ricvil on 08/10/2015 01:38 AM</a>
...
If one has a function with exponential format F=exp(k.x) and k is a constant then one can write k=(dF/dx)/F.

But if one has a function F=exp(k(x).x) then (dF/dx)/F=k(x) + xdk(x)/dx

If F has no exponential format is worse.

The wave solutions in spherical coodinates are the form  exp(+ik.r)/r and exp(-ik.r)/r only when r goes to infinity.
Yes, basically  γ = γ (r) hence it does not make sense that γ is treated as a constant to define

E = A e - γ r

γ = - (1/E) dE/dr = α + j β

because this is only true for γ = constant

So, really

-  (1/E) dE/dr  = γ + r dγ/dr

So Zeng and Fan's expression is exact when dγ/dr = 0, that is when γ is  constant.

and approximate for dγ/dr  ~ 0 (γ nearly constant)

so in the images shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414705#msg1414705 above and in Zeng and Fan's figures, the γ expression is more accurate as a measure of attenuation where γ is flat (where the gradient dγ/dr  ~ 0 ) and nearly constant, which is more nearly the case for values such that:

γ = 0  (NO ATTENUATION)

Thanks to our "NSF Peer Review Committee" with members Ricvl, Todd "WarpTech" and yours truly we have peer-reviewed Zeng and Fan's paper better than was done by the original editiorial review by Optics Express Journal:

Electromagnetic fields and transmission properties in tapered hollow metallic waveguides

Xiahui Zeng and Dianyuan Fan

https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-17-1-34&id=175583

Ricvl uncovered the important error that Zeng and Fan failed to properly derive the γ exponent, as they improperly considered it to be a constant in the initial part of their derivation and then a posteriori they inconsistently considered it to be a function of r.

I have properly solved the first order differential equation for γ(r):

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

that arises from solving for the exponent γ in the following expression:

Eθ = A e - γ r

(observe that Zeng and Fan did not solve this equation, instead they considered r dγ/dr << γ and hence assumed
γ = - (1/Eθ)*dEθ/dr).

When properly solving the differential equation (numerically, since it does not have a closed form solution, and it is quite difficult to solve numerically because it contains highly oscillating functions and it diverges at the boundaries)
I get the enclosed attenuation curve for γ for Yang/Shell in TE011 mode, with the RF feed off, standing waves, which does make sense (the solution based on Zeng & Fan's equation γ = - (1/Eθ)*dEθ/dr does not make sense because it contains a large geometrical magnification at the small end).

The attenuation is positive over the whole EM Drive, being close to zero over most of it but diverging to high attenuation at both ends because (1/Eθ)*dEθ/dr) diverges at the ends as previously explained due to the fact that the electric field Eθ must be zero at the bases.  Therefore the tangent electric field Eθ gets 100% attenuated at the small base and at the big base.  The attenuation curve for the other tangent electric field Eφ is identical.

Notice the asymmetry: there is more attenuation going on towards the small base.

Thus we have properly solved this problem for the case in which Eθ satisfies the bondary conditions for a resonant cavity.

Recall

1) Yang/Shell geometry:

bigDiameter = 0.201(*meter*);
smallDiameter = 0.1492(*meter*);
axialLength = 0.24(*meter*);

equivalently:

r1 = 0.693281 (*meter*); (*spherical small radius *)
r2 = 0.933978  (*meter*); (*spherical large radius *)
θw = 6.15933 (*degrees*); (*half-cone angle*)

2) the geometry we consider is as shown in this image: 

(CavityShape.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/10/2015 10:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415085#msg1415085">Quote from: Rodal on 08/10/2015 09:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415083#msg1415083">Quote from: SeeShells on 08/10/2015 09:21 PM</a>
...

Sigh. Lost? No, just regroup.
Thanks for the recap, I did't realize we handicapped the visual data as much as we did in truncating data simply making it unusable as a visual aid.

I hope the numbers haven't been truncated in the CSV files as well. Back to lurk and dig.

Shell
The numbers are in the csv files, but it is much more time consuming to post-process the csv files than to just click and look at the images.  All my 3 computers are otherwise occupied at the moment.  I had a small window of time in one computer which I used to calculate something that Todd will be interested in :)  Hope to get to this soon.

That's ok Jose, I'm going to take some time and do it. I need to.
Thanks,

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Possibles on 08/10/2015 10:02 PM
Hi everyone...

Been in lurking mode for a while now, and have been wringing my head for answers. No joy. I do have an idea, but I need to see the results of more vacuum tests to be reasonably confident.
I would like to take this opportunity to say this to the DIY guys. I would dearly love to build myself, but simply have no time or shop. I can only think in the rare moments I have. You really are pulling together and doing a great job.

But I need more null tests! I need someone to put a heating element in and test for deformation etc...
From different shaped frustums.
I need to see possible radiation leakage from the endplate.
I need a ramped test in a vacuum chamber bringing the power up to 100% and I need to see what happens when the magnetron pops. And in atmosphere too!
I need this because if on the off chance that this thing works, it will help me to understand the underlying process.

And I'm saying this because I believe that we are exciting a very particular set of circumstances. I honestly don't believe for a moment that the shape of the frustum is THAT important. After all, we have seen potential thrust from varying designs. I mean- look at the Cannae drive - Totally different. I can understand Temjar. He realized this too. Hence a hole you could stick your head through and peek around in.
MEEP will prove powerful in the end, I'm sure of it. But just not for the moment. Don't kill me Aero, I know you have done such fine work there...It can help guide us. But should not be considered so pertinent until we have figured the basics.
I think its time to balance the tests, and not get overloaded with results. There is also a high chance I've missed out on stuff here. It's been a busy month. And @Shell- how goes the measurement setup? Sorry to hear about your loss.

Bedtime now.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/10/2015 11:42 PM
It is thanks to aero running Meep that we are able to calculate and show:


1) The huge difference between having RF feed ON with travelling waves vs. the case examined by Greg Egan (RF feed OFF with standing waves)

2) The fact that there is Poynting vector directionally oriented with the RF feed ON that keeps growing with time exponentially, with the RF Feed on.

3) The fact that the stresses and hence the forces at the small and big bases are greatly influenced by the antenna with the RF feed ON

4) The difference between placing the antenna at the small end vs the big end

5)  The difference between placing the antenna at the axis of axi-symmetry vs being offset

6) The difficulties of exciting TE modes with dipole antennas

I say no, nobody here is overloaded,  rfmwguy and SeeShells can carry much more on their shoulders, so aero, keep it going with

7) Loop antennas to excite TE modes

8 ) Showing what happens when your turn the RF feed OFF

9) Modeling a waveguide entering the cavity to excite a TE mode in the cavity

10) Showing how steady-state is approached

etc.

:)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/11/2015 01:40 AM
 
Dr Rodal, I think there is a problem again.
Standing waves.
In the cavity, at least,  the fields are superpositions of two counter propagating waves, then one has (to simplify)
E=[a.exp(gamma.r)+b.exp(-gamma.r)].F(tetha,phi)
Repair, the expression above is just a aproximate model to fit the fields by exponential functions, where the correct is to use fractional spherical hankel functions (for spherical ends cavitys), where a,b and gamma will fataly be functions of r. At r>>1 the spherical  hankel function decay with 1/r.
Then how to differentiate a destructive interference at node fields from a infinity attenuation?
Worse, even with a,b and gamma being constants, when one take the derivative of E above, because the two signals of gamma (outward/inward from/to apex cone) one has
dE/dr=gamma[a.exp(gamma.r) -b.exp(-gamma.r)].F(theta,phi), and we lost original E function, then imagine with a,b and gamma being r functions.

This is just my way to think. You may, of course, disagree. :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 02:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415105#msg1415105">Quote from: Rodal on 08/10/2015 11:42 PM</a>
It is thanks to aero running Meep that we are able to calculate and show:


1) The huge difference between having RF feed ON with travelling waves vs. the case examined by Greg Egan (RF feed OFF with standing waves)

2) The fact that there is Poynting vector directionally oriented with the RF feed ON that keeps growing with time exponentially, with the RF Feed on.

3) The fact that the stresses and hence the forces at the small and big bases are greatly influenced by the antenna with the RF feed ON

4) The difference between placing the antenna at the small end vs the big end

5)  The difference between placing the antenna at the axis of axi-symmetry vs being offset

6) The difficulties of exciting TE modes with dipole antennas

I say no, nobody here is overloaded,  rfmwguy and SeeShells can carry much more on their shoulders, so aero, keep it going with

7) Loop antennas to excite TE modes

8 ) Showing what happens when your turn the RF feed OFF

9) Modeling a waveguide entering the cavity to excite a TE mode in the cavity

10) Showing how steady-state is approached

etc.

:)
I also am very glad aero is here doing work that has effectively moved this group forward with answers garnered in meep that simply were not available to the group in any other fashion. And with your help we got some very good answers.

But a couple of questions arise in how we can accomplish this with the data being displayed as it currently is.

How can we even know that a TM mode can be excited when you declared that the displayed modes were of little value after the filtering of the data files to rid the display of the artifacts and flashing colors. The only way I can see is not to be dependent on the display of meep and post-process but use another program, Wolfram or something else?

I need to know how to forecast the future use of meep and post processing because this second build I'll be going after building a stable frustum with ceramic gold plated endplates and an active feedback system to assure mode and frequency lock. If I can't get the answers here than I'll need to take a longer path.

I was busy today tracking down and talking with old contacts that are going to try to get me the ceramics for the endplates. I'll need to tell them before too long what size I want them to be.  The final shape of the ERD frustum will depend on how well meep and post processing can show what shape is optimal for it. For that we need as stable of an answer we can get. Simply for keeping a TE mode in a stabilized frustum, I think this is needed.


Shell






 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 02:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415128#msg1415128">Quote from: SeeShells on 08/11/2015 02:00 AM</a>
...
I also am very glad aero is here doing work that has effectively moved this group forward with answers garnered in meep that simply were not available to the group in any other fashion. And with your help we got some very good answers.

But a couple of questions arise in how we can accomplish this with the data being displayed as it currently is.

How can we even know that a TM mode can be excited when you declared that the displayed modes were of little value after the filtering of the data files to rid the display of the artifacts and flashing colors. The only way I can see is not to be dependent on the display of meep and post-process but use another program, Wolfram or something else?

I need to know how to forecast the future use of meep and post processing because this second build I'll be going after building a stable frustum with ceramic gold plated endplates and an active feedback system to assure mode and frequency lock. If I can't get the answers here than I'll need to take a longer path.

I was busy today tracking down and talking with old contacts that are going to try to get me the ceramics for the endplates. I'll need to tell them before too long what size I want them to be.  The final shape of the ERD frustum will depend on how well meep and post processing can show what shape is optimal for it. For that we need as stable of an answer we can get. Simply for keeping a TE mode in a stabilized frustum, I think this is needed.


Shell
Perhaps aero (or somebody else) will find a way to:

1) Plot all the electric fields with the same magnitude scale, and plot all the magnetic fields with the same magnitude scales

2) Plot the contour plots for the electromagnetic fields with an attached color bar showing the numerical magnitude of the contour colors.

I am not conversant with Meep but it seems to me that this need is something that many other users of Meep also have (to plot all the fields with the same magnitude and to be able to show the numerical value of the contours) and therefore may be an already existing command or something that somebody may have already documented how to do.

I know that other codes with which I am conversant (ANSYS, etc.) this is standard.  Actually the ability to show the numerical value of the contours was available in ANSYS from its first versions back in the early 1980's.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/11/2015 03:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415088#msg1415088">Quote from: Rodal on 08/10/2015 09:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414705#msg1414705">Quote from: Rodal on 08/10/2015 01:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414698#msg1414698">Quote from: WarpTech on 08/09/2015 11:58 PM</a>
...
...
...

Thanks to our "NSF Peer Review Committee" with members Ricvl, Todd "WarpTech" and yours truly we have peer-reviewed Zeng and Fan's paper better than was done by the original editiorial review by Optics Express Journal:

Electromagnetic fields and transmission properties in tapered hollow metallic waveguides

Xiahui Zeng and Dianyuan Fan

https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-17-1-34&id=175583

Ricvl uncovered the important error that Zeng and Fan failed to properly derive the γ exponent, as they improperly considered it to be a constant in the initial part of their derivation and then a posteriori they inconsistently considered it to be a function of r.

I have properly solved the first order differential equation for γ(r):

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

that arises from solving for the exponent γ in the following expression:

Eθ = A e - γ r

(observe that Zeng and Fan did not solve this equation, instead they considered r dγ/dr << γ and hence assumed
γ = - (1/Eθ)*dEθ/dr).

When properly solving the differential equation (numerically, since it does not have a closed form solution, and it is quite difficult to solve numerically because it contains highly oscillating functions and it diverges at the boundaries)
I get the enclosed attenuation curve for γ for Yang/Shell in TE011 mode, with the RF feed off, standing waves, which does make sense (the solution based on Zeng & Fan's equation γ = - (1/Eθ)*dEθ/dr does not make sense because it contains a large geometrical magnification at the small end).

The attenuation is positive over the whole EM Drive, being close to zero over most of it but diverging to high attenuation at both ends because (1/Eθ)*dEθ/dr) diverges at the ends as previously explained due to the fact that the electric field Eθ must be zero at the bases.  Therefore the tangent electric field Eθ gets 100% attenuated at the small base and at the big base.  The attenuation curve for the other tangent electric field Eφ is identical.

Notice the asymmetry: there is more attenuation going on towards the small base.

Thus we have properly solved this problem for the case in which Eθ satisfies the bondary conditions for a resonant cavity.

Recall
...

This is great! I have a question though. How can gamma be 0 at r = .85? It is not the attenuation exactly.

gamma = alpha + j*beta

You said "there is no imaginary part of gamma", meaning beta = 0 because it's a standing wave. Fine, but if gamma = 0, then what happened to the momentum of the wave?

gamma = j*k ~ p

Also, by assuming a standing wave solution, you are precluding there is any effect due to propagating waves. As @Ricvil said, the standing wave is the superposition of two propagating waves. The effect we are looking for pretty much requires that these two waves are not equal. So I don't think the assumption that beta=0 because they are standing waves is a good idea. It is like assuming the force we are looking for, doesn't exist.

I think it is required that beta =/= 0, or else the wave has no momentum to transfer to the frustum.

Thanks.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 03:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415126#msg1415126">Quote from: Ricvil on 08/11/2015 01:40 AM</a>

Dr Rodal, I think there is a problem again.
Standing waves.
In the cavity, at least,  the fields are superpositions of two counter propagating waves, then one has (to simplify)
E=[a.exp(gamma.r)+b.exp(-gamma.r)].F(tetha,phi)
Repair, the expression above is just a aproximate model to fit the fields by exponential functions, where the correct is to use fractional spherical hankel functions (for spherical ends cavitys), where a,b and gamma will fataly be functions of r. At r>>1 the spherical  hankel function decay with 1/r.
Then how to differentiate a destructive interference at node fields from a infinity attenuation?
Worse, even with a,b and gamma being constants, when one take the derivative of E above, because the two signals of gamma (outward/inward from/to apex cone) one has
dE/dr=gamma[a.exp(gamma.r) -b.exp(-gamma.r)].F(theta,phi), and we lost original E function, then imagine with a,b and gamma being r functions.

This is just my way to think. You may, of course, disagree. :)

There is NO approximation, and there is no fitting.  There is NO exponential fit, because γ is not a constant here, γ is a function of r, defined to give the identical part of Eθ that is solely expressible in term of r .  The meaning of γ is only as described by the mathematical expression, not more and not less.

γ is not a closed-form expression, it is not expressible by any known function known in any text.  γ is given by Wolfram Mathematica as the solution of the differential equation, it is NOT a known classical function, it is NOT an exponential with a constant exponent multiplying r.

It is just a mapping of the original function into another function that gives exactly the same result.

It is exactly the same. 

The solution Eθ in terms of γ exponential and A is identical to the one expressed in terms of Spherical Bessel functions and the Legendre Associated functions, it is just expressed in a different form. 

Tomorrow I will post a comparison plot to show this identity.  It is identical by construction

/////////////////////////////////////////////////////////////////

As to interference, separate waves and other issues present in the transient when the RF feed is ON, I have not dealt with those aspects. I have only dealt with the standing wave solution. To deal with the transient with the RF feed ON, yes I would have to use Hankel functions.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 03:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415143#msg1415143">Quote from: WarpTech on 08/11/2015 03:28 AM</a>
...

This is great! I have a question though. How can gamma be 0 at r = .85? ..
gamma is zero at r=0.85 because at r=0.85 the r-dependent part of Eθ is 1.  An exponential raised to a zero value gives you 1.  The constants defining Eθ (as well as the θ  and phi dependent variables) are absorbed into "A":

Eθ = A e - γ r

for γ = 0

gives

Eθ /A = 1

one is the maximum value of Eθ /A, which has been normalized to have a maximum value of 1 by construction.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 03:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415143#msg1415143">Quote from: WarpTech on 08/11/2015 03:28 AM</a>
...
Also, by assuming a standing wave solution, you are precluding there is any effect due to propagating waves. As @Ricvil said, the standing wave is the superposition of two propagating waves. The effect we are looking for pretty much requires that these two waves are not equal. So I don't think the assumption that beta=0 because they are standing waves is a good idea. It is like assuming the force we are looking for, doesn't exist.

I think it is required that beta =/= 0, or else the wave has no momentum to transfer to the frustum.

Thanks.
Todd

Of course.  But that is all that I solved. As I wrote in my post I only used the standing wave solution.  Unequal travelling waves in opposite directions, interference, or other effects present with the RF feed on, or a force, are not going to be found here.  I used only the standing wave solution, for which there is no force according to Maxwell's solution.

Before we go to Hankel functions we have to start from a known solution to see whether the method is sound and gives a correct solution to a known problem.

Particularly when Zeng and Fan have the incorrect solution and nobody from the peer reviewers caught it.


To consider a waveguide or an RF cavity transient solution I would have to use the same methodology using spherical Hankel functions instead of spherical Bessel functions, as I had posted previously :)

Piano piano si va sano e lontano

(dettagliopunto2010.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 04:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415140#msg1415140">Quote from: Rodal on 08/11/2015 02:49 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415128#msg1415128">Quote from: SeeShells on 08/11/2015 02:00 AM</a>
...
I also am very glad aero is here doing work that has effectively moved this group forward with answers garnered in meep that simply were not available to the group in any other fashion. And with your help we got some very good answers.

But a couple of questions arise in how we can accomplish this with the data being displayed as it currently is.

How can we even know that a TM mode can be excited when you declared that the displayed modes were of little value after the filtering of the data files to rid the display of the artifacts and flashing colors. The only way I can see is not to be dependent on the display of meep and post-process but use another program, Wolfram or something else?

I need to know how to forecast the future use of meep and post processing because this second build I'll be going after building a stable frustum with ceramic gold plated endplates and an active feedback system to assure mode and frequency lock. If I can't get the answers here than I'll need to take a longer path.

I was busy today tracking down and talking with old contacts that are going to try to get me the ceramics for the endplates. I'll need to tell them before too long what size I want them to be.  The final shape of the ERD frustum will depend on how well meep and post processing can show what shape is optimal for it. For that we need as stable of an answer we can get. Simply for keeping a TE mode in a stabilized frustum, I think this is needed.


Shell
Perhaps aero (or somebody else) will find a way to:

1) Plot all the electric fields with the same magnitude scale, and plot all the magnetic fields with the same magnitude scales

2) Plot the contour plots for the electromagnetic fields with an attached color bar showing the numerical magnitude of the contour colors.

I am not conversant with Meep but it seems to me that this need is something that many other users of Meep also have (to plot all the fields with the same magnitude and to be able to show the numerical value of the contours) and therefore may be an already existing command or something that somebody may have already documented how to do.

I know that other codes with which I am conversant (ANSYS, etc.) this is standard.  Actually the ability to show the numerical value of the contours was available in ANSYS from its first versions back in the early 1980's.

The numerical field intensity values may be available in some convenient way that I just don't know about, but I have looked. Other meepers looking would be very helpful.

They are available, just not convenienly, by using the "-verbose" switch on h5topng. Unfortunately, using that will require two separate runs, but I guess any method would require two separate runs at some level. Here is the verbose output from generating one png file.

Quote
steve@steve-p6720f:~$ h5topng -v -t 0  -z 214 ./Shell-2-d-dipole-loop-out/hx.h5
Using colormap "gray" in file "/usr/share/h5utils/colormaps/gray".
grayscale color map (white to black)
2 color entries read from colormap file.
Scaling opacity by 1
data rank = 4
------
reading from "./Shell-2-d-dipole-loop-out/hx.h5", slice at 214 in z dimension, slice at 0 in t dimension.
data ranges from -0.00012754 to 0.00012754.
writing "./Shell-2-d-dipole-loop-out/hx.png" from 196x196 input data.
all data range from -0.00012754 to 0.00012754.

I manually made 12 runs of h5topng, and extracted the following data ranges.

Range of data values in Shell-2-d-dipole-loop64-out

slice t 00, z 15 Big end
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.

hx all data range from -0.000538633 to 0.000538633.
hy all data range from -0.000356036 to 0.000356036.
hz all data range from -4.65749e-05 to 3.78542e-05.

slice t 00 z 214 Small end
ex all data range from -1.60461e-05 to 1.60461e-05.
ey all data range from -3.20985e-05 to 3.20985e-05.
ez all data range from -4.04811e-05 to 4.04811e-05.

hx all data range from -0.00012754 to 0.00012754.
hy all data range from -0.000287974 to 0.000287974.
hz all data range from -1.07156e-05 to 1.61666e-05.


As I understand you, what you need is to have three png files, ex, ey, ez scaled to the maximum range of the E components and three, hx hy, hz scaled to the maximum range for the H component - for each time slice and each of the 4 geometry slices per time slice. That would be the ez range and the hx range for the first case above, but note that max value and min value won't necessarily always be from the same component as the second hz range above indicates.

Scaling the range of values using this approach is quite unwieldy to do manually, as there are I believe 336 pngs for a standard data set as I have been using, but also, we might benefit by extending that data set to 2 full cycles, or even more.

Does anyone here want to volunteer to create a bash shell file that runs the data set in verbose mode capturing the terminal output in the log file, then scan that log file, extract the correct range of values and scale the h5topng max and min switches, then run the data set again for upload?  Conceptually it should be straight forward but I only recognize bash in passing, are almost strangers. Of course one could use Octave or MatLab to read the log file and extract the pertinent data, or even write a purpose program that simply scans and extracts the data then writes a new shell file with as many h5topng command lines as needed. That might be safer and the 336 + command line shell file would be "throw away" so it wouldn't need to be "slick."

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/11/2015 05:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414883#msg1414883">Quote from: tleach on 08/10/2015 03:25 PM</a>
EDIT:  If I get a chance tonight I'll try to add Notsosureofit's formula to my spreadsheet and see what happens

Oh my gosh. 

Notsureofit's formula is much more difficult to program into excel.  You have to calculate TM modes, TE modes, Angular Frequency, and p (quantum number in the longitudinal direction, for modes TMmnp and TEmnp) and use them as inputs.  This will take much longer than I realized.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/11/2015 06:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414995#msg1414995">Quote from: Rodal on 08/10/2015 06:30 PM</a>
ALL electric fields should be shown on the same scale and all magnetic fields should be shown to the same scale.  Otherwise there is no comprehension.
  A common dB scale should be appropriate.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 07:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415164#msg1415164">Quote from: Mezzenile on 08/11/2015 06:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414995#msg1414995">Quote from: Rodal on 08/10/2015 06:30 PM</a>
ALL electric fields should be shown on the same scale and all magnetic fields should be shown to the same scale.  Otherwise there is no comprehension.
  A common dB scale should be appropriate.
Why use a logarithm scale for showing the magnitude of the electromagnetic fields?
What advantage is there in using a logarithmic scale? I see disadvantages as a logarithmic scale would distort the fields and really distort the mode shapes which are usually displayed in texts with a linear scale and hence become difficult to recognize.  We want to be able to identify the mode shapes so that we know whether TE or TM, etc.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=632192;image)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 08/11/2015 08:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415179#msg1415179">Quote from: Rodal on 08/11/2015 07:40 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415164#msg1415164">Quote from: Mezzenile on 08/11/2015 06:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414995#msg1414995">Quote from: Rodal on 08/10/2015 06:30 PM</a>
ALL electric fields should be shown on the same scale and all magnetic fields should be shown to the same scale.  Otherwise there is no comprehension.
  A common dB scale should be appropriate.
Why use a logarithm scale for showing the magnitude of the electromagnetic fields?
What advantage is there in using a logarithmic scale? I see disadvantages as a logarithmic scale would distort the fields and really distort the mode shapes which are usually displayed in texts with a linear scale and hence become difficult to recognize.  We want to be able to identify the mode shapes so that we know whether TE or TM, etc.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=632192;image)

Dr. Rodal just s curious question. Do you consider to use fractal geometry when trying to identify the mode shapes? I was just wondering, when I know fractal geometry actually works with all kinds of crazy repeating patterns as far as I know. EmDrive might be the case.

"A fractal is a natural phenomenon or a mathematical set that exhibits a repeating pattern that displays at every scale"  https://en.wikipedia.org/wiki/Fractal

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/11/2015 09:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415179#msg1415179">Quote from: Rodal on 08/11/2015 07:40 AM</a>

Why use a logarithm scale for showing the magnitude of the electromagnetic fields?
What advantage is there in using a logarithmic scale? I see disadvantages as a logarithmic scale would distort the fields and really distort the mode shapes which are usually displayed in texts with a linear scale and hence become difficult to recognize.  We want to be able to identify the mode shapes so that we know whether TE or TM, etc.

If your concern is to appreciate level ratio of more than 1000 on a screen, a dB scale makes sense.

E-field pattern for the TE01 mode below cutoff, plotted with a dB scale and a lower limit of -40 dB.
(2z8s0hs.jpg)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/11/2015 09:57 AM

https://people.math.osu.edu/gerlach.1/math/BVtypset/node122.html

About hankel and bessel, see (512) and (513) of property 14 of above reference.
For non integer order, just a linear combination and can be inverted, expressing hankel functions by bessel functions and vice versa. The boundary conditions will set the coeficients of one or other representation.
The spherical ones are basicaly related by a (1/r)^0.5 factor.

You prefer bessel, and I prefer hankel.

"É trocar seis por meia dúzia".

:)

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415149#msg1415149">Quote from: Rodal on 08/11/2015 03:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415143#msg1415143">Quote from: WarpTech on 08/11/2015 03:28 AM</a>
...
Also, by assuming a standing wave solution, you are precluding there is any effect due to propagating waves. As @Ricvil said, the standing wave is the superposition of two propagating waves. The effect we are looking for pretty much requires that these two waves are not equal. So I don't think the assumption that beta=0 because they are standing waves is a good idea. It is like assuming the force we are looking for, doesn't exist.

I think it is required that beta =/= 0, or else the wave has no momentum to transfer to the frustum.

Thanks.
Todd

Of course.  But that is all that I solved. As I wrote in my post I only used the standing wave solution.  Unequal travelling waves in opposite directions, interference, or other effects present with the RF feed on, or a force, are not going to be found here.  I used only the standing wave solution, for which there is no force according to Maxwell's solution.

Before we go to Hankel functions we have to start from a known solution to see whether the method is sound and gives a correct solution to a known problem.

Particularly when Zeng and Fan have the incorrect solution and nobody from the peer reviewers caught it.


To consider a waveguide or an RF cavity transient solution I would have to use the same methodology using spherical Hankel functions instead of spherical Bessel functions, as I had posted previously :)

Piano piano si va sano e lontano

(dettagliopunto2010.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/11/2015 11:19 AM
Several of the EM Drive builders have experienced differences in measured thrust based on the direction that the Frustums smaller end was facing at the time ("Horizontally") during testing. Should some other test data be included as standard test data, to better exclude/include possible contributing factors to current test results?

a) Could this be somehow related to what direction the earth is rotating in comparison to the longitude, latitude and altitude and starting position relative to degrees from true north of the Frustums small end when the Frustum is mounted facing horizontally, at the testers location at the time of testing?

b) Could this be somehow related to what the earths current magnetic field is at any given longitude, latitude and altitude of the testers location at the time of testing?

c) Could the Atmospheric pressure/Barometric Pressure at the testers location be contributing to differences in measured thrust at the time of testing? After all some of the measured thrust has been no greater than enough to move a snowflake.

d) Could Relative Humidity at a specific temperature at the testers location at the time of testing be contributing to measured thrust at the testers location?

e) Include vertical thrust measurements when the Frustum is mounted and facing horizontally as secondary test data. During the same test window and starting with the Frustums small end being at the same degree from true north postion as any horizontal test which was done in the same test window. Vice versa ("minus any need to start at any true north position") for Frustums being tested with their smaller end being tested vertically.

Point being: Could any of the above, be causing any differences in measured thrust during testing?

Would it not be a prudent thing to be including all the above information at least at this time with other test data results?

At time of test:

1. Longitude

2. Latitude

3. Altitude

4. Barometric Pressure

5, Relative Humidity ("With temperature for reference")

6. Horizontal starting direction of Frustum smaller end in degrees from true north, when the Frustum is mounted facing horizontally

7. Measurements of vertical thrust not just horizontal thrust when the Frustums small end is mounted and facing horizontally. Using the same starting position that any prior test, during the same test window that horizontal thrust testing started from. Vice versa  for Frustums being tested with their smaller end being tested vertically ("minus any need to start at any true north position").

To be able to see if any of the above are somehow involved or have any impact on whatever test results are being seen and produced at any specific time. Even when using the same EM Drive build, at the same location, during different testing times.

Any anomalies or even valid and real EM results which might be involved in producing thrust results during testing of EM Drives, most likely are not likely to always present themselves currently, as being exclusively limited to only a pure horizontal or vertical thrust plane of a Frustum undergoing a test.

Any thrust being generated for any reasons. Must be being currently generated at different angles ("Simultaneously in both the horizontal and vertical directions") in reference to the mounting plane of any given Frustum build and test setup. Yet thrust is only being measured ("currently") in the absolute direction that the Frustum small/large end was currently pointing in. At the time of any given test.

Edit: Typos

Don
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/11/2015 11:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415077#msg1415077">Quote from: ElizabethGreene on 08/10/2015 08:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414913#msg1414913">Quote from: Mulletron on 08/10/2015 04:21 PM</a>
For Shawyer to try and patent this before there was even a dream of a viable commercial product is ludicrous.

I vigorously disagree.  Mr. Shawyer has, hypothetically, discovered something that we thought was impossible. As such, in addition to his Nobel prize, he is fully entitled to own that intellectual property for the full duration of the patent and take full financial advantage of it. His right to make a billion dollars on this is just as real as your right to make a billion dollars on any improvements you make to it.

A patent is a reward and incentive for the inventor's investment of effort, risk, failures, money, time, and life in creating a device or idea. If they choose to open source it or freely license it then that is their choice. They are under no ethical or moral obligation to do so.

Quote
He should have opened it up to research at the beginning.
He did.  He's been writing about it publicly for a decade to anyone who would listen.  For his trouble he's been called a fraud and charlatan.  He's been mocked and ridiculed.  To imply that he's hoarded this to himself is a particularly bitter insult.

Quote
Based on what I know, the current iteration is obviously not viable.
Your knowledge is incorrect.  He discovered the Shawyer effect and then spent years inventing, experimenting, and refining devices that generated thrust from RF energy.  The device accomplished the "impossible".  That certainly seems "viable" to me.

Quote
If members of the public are able to own a personal stake in something as evolutionary as this, some will gladly invest enormous amounts of effort, even with no guarantee of any financial reward or any success; like us.
Mr. Shawyer built this technology "with no guarantee of any financial reward or any success."  How is his contribution somehow inferior to what we would create?

Quote
So can it be done? Should it be done? If so, we need help...
We just have to make it roll. The rest is history.

Patent law is not simple at all.  Even worse, it varies wildly by country and it changes over time.  In the US, there is a tiny window for building a copy of a device to determine the accuracy of the specification, for the sole purpose of gratifying a philosophical taste, or curiosity, or for mere amusement.  I currently work within those exceptions.  Any use beyond that should be negotiated with Mr. Shawyer.

-eag

P.s. ... don't forget that Cannae has patents on this kit too.  Even though their drive !did not work! they still own part of the IP.

Good, thank you for lighting off discussion. Now I want to make it clear that my intent is NOT to deprive Shawyer of his rights to anything. The intent is to spur development. Simple as that.

The intent is to first find any evidence whatsoever which will prove the existence of the "Shawyer effect." Nobody has been able to prove that these devices function as useful thrusters. Folks may argue, well Shaywer himself proved it or Eagleworks did. There is no consensus that the "Shawyer effect" exists, therefore any utility to such an invention is simply conjecture. So as it stands right now, Shawyer owns the patent to a bet, a gamble. A 50/50 yes or no that he has something useful. The consensus of the world is that it doesn't work. I am agnostic.

I might as well patent the light saber right now because eventually somebody else will figure out the details for me, right?

I did bring up the idea to him of opening up his invention for open source development*. I got no answer. No surprise there. I will absolutely tell you, that if the answer is eureka it really works..and the consensus is that it works, he'll get his Nobel and loads of cash.

But there will be no protection provided by his patents. Bigger businesses with deeper pockets will just take it. I don't want to see that happen. It happens all the time, especially in tech.

So my vision here is:

1) Confirm that the Shawyer effect even really exists (which is what we're all doing here right now). If not, then put it in the closet with the lifters.
2) If we learn enough so as to make a meaningful contribution to theory or engineering which can warrant a clear reason to say we have something unique, then
3) Fork it and open it up.

Quote
Your knowledge is incorrect.  He discovered the Shawyer effect and then spent years inventing, experimenting, and refining devices that generated thrust from RF energy.  The device accomplished the "impossible".  That certainly seems "viable" to me.

This quote tells me that you believe EmDrive really works and is absolutely useful.

* http://www.teslamotors.com/blog/all-our-patent-are-belong-you (like this)

Edits: readability

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 08/11/2015 11:41 AM
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

New EmDrive test results by PaulTheSwag posted few minutes ago on the reddit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 11:50 AM
Shawyer has enough problems with the theory people, and is utterly out of his depth in that domain. Therefore for Shawyer to win, he has to succeed experimentally. This means inter alia reproducibility. Unfortunately for Shawyer, he has not opened up in the sense of seeding several different labs with identical devices whose parameters can be varied so as to enact various control protocols. Nobody knows the true details of that turntable device. He fails by not sharing. He will not be believed.

What else is there? Low SNR from EW, confusing results from Cannae, but stellar reports from Yang whose lab is protected by the Chinese military. That's about as opposite to "open" as you can get, and therefore the most suspicious. We draw a blank experimentally too, across the board.

So the only way out here is what people on this forum are doing - building it themselves. It doesn't have to be this way, but it's been forced to be this way.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 12:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415207#msg1415207">Quote from: Chrochne on 08/11/2015 11:41 AM</a>
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

New EmDrive test results by PaulTheSwag posted few minutes ago on the reddit.
Dramatic in terms of the large measured thrust levels, but confusing too. Why does the measured thrust bang up and down like that under constant input power? Is this oscillation about the fulcrum? Is it a ballistic measuring device?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: martinc on 08/11/2015 12:12 PM
just a note on the theory side
it's interesting to find that resonant cavities in particle accelerators (and other applications) there is an unwanted effect called lorentz force which i've seen mention here before a few times. they fight against this effect because it induces various distortions including to the body of the cavity. maybe what the EM drive does is to amplify this effect instead.
the very name 'lorentz' in interesting as his equations are at the core of relativity, in terms of the lorentz transformation in special relativity, and the lorentz force equation as an input to the electromagnetic stress–energy tensor in general relativity.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 12:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415145#msg1415145">Quote from: Rodal on 08/11/2015 03:40 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415126#msg1415126">Quote from: Ricvil on 08/11/2015 01:40 AM</a>

Dr Rodal, I think there is a problem again.
Standing waves.
In the cavity, at least,  the fields are superpositions of two counter propagating waves, then one has (to simplify)
E=[a.exp(gamma.r)+b.exp(-gamma.r)].F(tetha,phi)
Repair, the expression above is just a aproximate model to fit the fields by exponential functions, where the correct is to use fractional spherical hankel functions (for spherical ends cavitys), where a,b and gamma will fataly be functions of r. At r>>1 the spherical  hankel function decay with 1/r.
Then how to differentiate a destructive interference at node fields from a infinity attenuation?
Worse, even with a,b and gamma being constants, when one take the derivative of E above, because the two signals of gamma (outward/inward from/to apex cone) one has
dE/dr=gamma[a.exp(gamma.r) -b.exp(-gamma.r)].F(theta,phi), and we lost original E function, then imagine with a,b and gamma being r functions.

This is just my way to think. You may, of course, disagree. :)

There is NO approximation, and there is no fitting.  There is NO exponential fit, because γ is not a constant here, γ is a function of r, defined to give the identical part of Eθ that is solely expressible in term of r .  The meaning of γ is only as described by the mathematical expression, not more and not less.

γ is not a closed-form expression, it is not expressible by any known function known in any text.  γ is given by Wolfram Mathematica as the solution of the differential equation, it is NOT a known classical function, it is NOT an exponential with a constant exponent multiplying r.

It is just a mapping of the original function into another function that gives exactly the same result.

It is exactly the same. 

The solution Eθ in terms of γ exponential and A is identical to the one expressed in terms of Spherical Bessel functions and the Legendre Associated functions, it is just expressed in a different form. 

Tomorrow I will post a comparison plot to show this identity.  It is identical by construction

/////////////////////////////////////////////////////////////////

As to interference, separate waves and other issues present in the transient when the RF feed is ON, I have not dealt with those aspects. I have only dealt with the standing wave solution. To deal with the transient with the RF feed ON, yes I would have to use Hankel functions.

As promised, I attach a plot showing that the result of exponentiating the gamma function γ I derived (times -r)

Eθ = A e - γ r

results in exactly the same function as the exact electric field Eθ divided by A: Eθ /A.  There is no approximation. 

Again, this is by construction.  The gamma function γ(r) cannot be expressed in terms of any known function appearing in any textbook, it has to be obtained as a numerical solution to the differential equation:

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

By contrast, the γ function as defined by Zeng and Fan (who define it as  γ = - (1/Eθ)*dEθ/dr )
does not result in Eθ / A = e - γ r as is easy to show.  See the bottom attached image, showing divergence at small radius near the small base.

A plot of what proper definition of the gamma function γ(r) looks like is shown here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415088#msg1415088

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 12:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415211#msg1415211">Quote from: deltaMass on 08/11/2015 12:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415207#msg1415207">Quote from: Chrochne on 08/11/2015 11:41 AM</a>
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

New EmDrive test results by PaulTheSwag posted few minutes ago on the reddit.
Dramatic in terms of the large measured thrust levels, but confusing too. Why does the measured thrust bang up and down like that under constant input power? Is this oscillation about the fulcrum? Is it a ballistic measuring device?

Apply a sudden force to a undamped fulcrum and it will do as shown. Oscillate up and down before settling into the final displacement.

His non lengthened frustum resonants in TE212 mode at 2.4219 GHz, which should be inside the magnetron's output freq range. Predicted Force generation is around 200mN at 1,000Ws, assuming a Q of 50,000.

At his +50mm length extension, should get TE013 resonance at 2.4439GHz. Assuming the Q stays the same, Force grows to around 240mN. Additionally this frequency is closer to the centre frequency of the magnetron and should get more power inside the cavity.

My latest EMDrive calculator is here:

https://drive.google.com/file/d/0B7kgKijo-p0iUnlaXzc0OFVvc00/view?usp=sharing

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 12:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415211#msg1415211">Quote from: deltaMass on 08/11/2015 12:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415207#msg1415207">Quote from: Chrochne on 08/11/2015 11:41 AM</a>
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

New EmDrive test results by PaulTheSwag posted few minutes ago on the reddit.
Dramatic in terms of the large measured thrust levels, but confusing too. Why does the measured thrust bang up and down like that under constant input power? Is this oscillation about the fulcrum? Is it a ballistic measuring device?

He says that he got much larger results with the extension to the truncated cone.  I could not find an image for what the extension to the cone looks like, nor its dimensions.  Could somebody please be so kind as to link to the image showing the extension and its dimensions ?

PS: I understand he says he used the NASA Eagleworks dimensions, if that is the case, the resonant frequency at near 2.45 GHz should be TM212 (transverse magnetic, same mode excited by Iulian Berca), instead of TE212 (transverse electric)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 01:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415219#msg1415219">Quote from: Rodal on 08/11/2015 12:38 PM</a>
PS: I understand he says he used the NASA Eagleworks dimensions, if that is the case, the resonant frequency at near 2.45 GHz should be TM212 (transverse magnetic, same mode excited by Iulian Berca), instead of TE212 (transverse electric)

As calculated.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 01:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415224#msg1415224">Quote from: TheTraveller on 08/11/2015 01:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415219#msg1415219">Quote from: Rodal on 08/11/2015 12:38 PM</a>
PS: I understand he says he used the NASA Eagleworks dimensions, if that is the case, the resonant frequency at near 2.45 GHz should be TM212 (transverse magnetic, same mode excited by Iulian Berca), instead of TE212 (transverse electric)

As calculated.

As calculated by NASA: 2.45 GHz TM212 (transverse MAGNETIC mode) (not TE212) for NASA's truncated cone dimensions (no dielectric insert)

My exact solution agrees with NASA

Full NASA report attached below

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 01:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415227#msg1415227">Quote from: Rodal on 08/11/2015 01:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415224#msg1415224">Quote from: TheTraveller on 08/11/2015 01:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415219#msg1415219">Quote from: Rodal on 08/11/2015 12:38 PM</a>
PS: I understand he says he used the NASA Eagleworks dimensions, if that is the case, the resonant frequency at near 2.45 GHz should be TM212 (transverse magnetic, same mode excited by Iulian Berca), instead of TE212 (transverse electric)

As calculated.

As calculated by NASA: 2.45 GHz TM212 (transverse MAGNETIC mode) (not TE212) for NASA's truncated cone dimensions (no dielectric insert)

My exact solution agrees with NASA

As calculated by NASA: 1.88 GHz TE212 (transverse ELECTRIC mode occurs at a much lower frequency than 2.45 GHz)   for NASA's truncated cone dimensions (no dielectric insert)

My exact solution agrees with NASA

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 01:25 PM
I'm still confused. Are we looking at a single impulsive event, or a steady-state force?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 01:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415227#msg1415227">Quote from: Rodal on 08/11/2015 01:20 PM</a>
As calculated by NASA: 2.45 GHz TM212 (transverse MAGNETIC mode) (not TE212) for NASA's truncated cone dimensions (no dielectric insert)

My exact solution agrees with NASA

Full NASA report attached below

And the Force they measured when they excited the frustum in TM213 mode at the predicted freq was?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 01:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415230#msg1415230">Quote from: Rodal on 08/11/2015 01:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415229#msg1415229">Quote from: deltaMass on 08/11/2015 01:25 PM</a>
I'm still confused. Are we looking at a single impulsive event, or a steady-state force?
The unraveling of the EM Drive "force measurement" this is what is great about replications.
The South African experiment does not show a constant steady-state force.

His fulcrum is undamped and will oscillate for some time before settling at the final value. You know that so why the comment?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 01:33 PM
Calculation of resonant frequencies in cavities is well-known and established.  Has been replicated routinely in thousands of carefully designed experiments.  Routinely done at CERN and other particle accelerators using Finite Element Analysis . The hundreds of thousands of readers of this thread can conduct their own calculations based on the NASA dimensions (see attached NASA report for dimensions frequencies and mode shape) and independently verify whether the mode shape at 2.45 GHz is TM212 or TE212
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 01:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415235#msg1415235">Quote from: TheTraveller on 08/11/2015 01:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415230#msg1415230">Quote from: Rodal on 08/11/2015 01:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415229#msg1415229">Quote from: deltaMass on 08/11/2015 01:25 PM</a>
I'm still confused. Are we looking at a single impulsive event, or a steady-state force?
The unraveling of the EM Drive "force measurement" this is what is great about replications.
The South African experiment does not show a constant steady-state force.

His fulcrum is undamped and will oscillate for some time before settling at the final value. You know that so why the comment?
There is always some amount of damping in any set-up (if there would be no damping we would be able to have perpetual motion machines, which is impossible).  But fair enough, since I have not had a chance to do detailed modeling of his set-up (I don't even know his dimensions) I withdraw my comments until I have the chance to model his set-up.

Can you provide a link to his cone dimensions, masses, displacement/force measuring device, etc., for me to model his experiment?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 01:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415228#msg1415228">Quote from: Rodal on 08/11/2015 01:24 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415227#msg1415227">Quote from: Rodal on 08/11/2015 01:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415224#msg1415224">Quote from: TheTraveller on 08/11/2015 01:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415219#msg1415219">Quote from: Rodal on 08/11/2015 12:38 PM</a>
PS: I understand he says he used the NASA Eagleworks dimensions, if that is the case, the resonant frequency at near 2.45 GHz should be TM212 (transverse magnetic, same mode excited by Iulian Berca), instead of TE212 (transverse electric)

As calculated.

As calculated by NASA: 2.45 GHz TM212 (transverse MAGNETIC mode) (not TE212) for NASA's truncated cone dimensions (no dielectric insert)

My exact solution agrees with NASA

As calculated by NASA: 1.88 GHz TE212 (transverse ELECTRIC mode occurs at a much lower frequency than 2.45 GHz)   for NASA's truncated cone dimensions (no dielectric insert)

My exact solution agrees with NASA

Proof of frustum resonance in any mode is measured Force generation. No Force generation, means the mode and resonance calc is not correct.

What NASA needs to show is the S11 return loss scans for those frequencies. When you see the return loss dB dips, then you know there is a resonant mode. Need a different antenna to properly excite TE and TM modes.

EW's internal frustum length only needs to be 3mm longer than SA Paul's frustum length for the 2.445GHz resonance to turn into a 2.422GHz resonance.

Thus I suggest the attached does show a TE213 resonance that EW found, Paul in SA found and my spreadsheet predicts.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 01:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415238#msg1415238">Quote from: Rodal on 08/11/2015 01:38 PM</a>
There is always some amount of damping in any set-up (if there would be no damping we would be able to have perpetual motion machines, which is impossible).  But fair enough, since I have not had a chance to do detailed modeling of his set-up (I don't even know his dimensions) I withdraw my comments until I have the chance to model his set-up.

Can you provide a link to his cone dimensions, masses, displacement/force measuring device, etc., for me to model his experiment?

https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 01:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415239#msg1415239">Quote from: TheTraveller on 08/11/2015 01:44 PM</a>
...
Proof of frustum resonance in any mode is measured Force generation. No Force generation, means the mode and resonance calc is not correct.

What NASA needs to show is the S11 return loss scans for those frequencies. When you see the return loss dB dips, then you know there is a resonant mode. Need a different antenna to properly excite TE and TM modes.

EW's internal frustum length only needs to be 3mm longer than SA Paul's frustum length for the 2.445GHz resonance to turn into a 2.422GHz resonance.

Thus I suggest the attached does show a TE212 resonance that EW found, Paul in SA found and my spreadsheet predicts.

Therefore according to you CERN, MIT, CalTech, Princeton, etc., and anybody that calculates frequencies and mode shapes of resonant cavities using Finite Element analysis and exact solutions are getting wrong results and they should immediately switch to using your Excel spreadsheet to calculate resonant frequencies and mode shapes of resonant cavities?

X-Ray and others in this thread, for example should replace their methods of analysis and start using your Excel spreadsheet to calculate resonant frequencies and mode shapes?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 01:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415237#msg1415237">Quote from: Rodal on 08/11/2015 01:33 PM</a>
Calculation of resonant frequencies in cavities is well-known and established.  Has been replicated routinely in thousands of carefully designed experiments.  Routinely done at CERN and other particle accelerators using Finite Element Analysis . The hundreds of thousands of readers of this thread can conduct their own calculations based on the NASA dimensions (see attached NASA report for dimensions frequencies and mode shape) and independently verify whether the mode shape at 2.45 GHz is TM212 or TE212

As I said proof of the calc is seeing a S11 return loss dip at the calculated freq. Is easy to do. EW has the VNA to do the scan. So why no scans to back the calcs?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 02:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415242#msg1415242">Quote from: Rodal on 08/11/2015 01:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415239#msg1415239">Quote from: TheTraveller on 08/11/2015 01:44 PM</a>
...
Proof of frustum resonance in any mode is measured Force generation. No Force generation, means the mode and resonance calc is not correct.

What NASA needs to show is the S11 return loss scans for those frequencies. When you see the return loss dB dips, then you know there is a resonant mode. Need a different antenna to properly excite TE and TM modes.

EW's internal frustum length only needs to be 3mm longer than SA Paul's frustum length for the 2.445GHz resonance to turn into a 2.422GHz resonance.

Thus I suggest the attached does show a TE212 resonance that EW found, Paul in SA found and my spreadsheet predicts.

Therefore according to you CERN, MIT, CalTech, Princeton, etc., and anybody that calculates frequencies and mode shapes of resonant cavities using Finite Element analysis and exact solutions are getting wrong results and they should immediately switch to using your Excel spreadsheet to calculate resonant frequencies and mode shapes?

Point was if NASA had done a S11 return loss scan on the real frustum, to find the freq the return loss dB drops, they would have confirmed their calcs were correct.

As for the other guys they probably use SuperFish to model and design their cavities.
http://www.lanl.gov/projects/feynman-center/technologies/software/poisson-superfish.php

Do a Google search for superfish resonant cavity to turn up a lot of hits.
https://www.google.com.au/search?q=superfish+resonant+cavity&oq=superfish+resonant+cavity&aqs=chrome..69i57.7017j0j4&sourceid=chrome&es_sm=122&ie=UTF-8

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 02:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415241#msg1415241">Quote from: TheTraveller on 08/11/2015 01:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415238#msg1415238">Quote from: Rodal on 08/11/2015 01:38 PM</a>
There is always some amount of damping in any set-up (if there would be no damping we would be able to have perpetual motion machines, which is impossible).  But fair enough, since I have not had a chance to do detailed modeling of his set-up (I don't even know his dimensions) I withdraw my comments until I have the chance to model his set-up.

Can you provide a link to his cone dimensions, masses, displacement/force measuring device, etc., for me to model his experiment?

https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/
I see the dimensions of the truncated cone there but I don't see enough details to do any modeling: no masses and most bothersome, no dimensions or description of the testing set-up except:

Quote
A knife-edge fulcrum is composed of a long balancing beam which rests on two razor edges. This allows for very sensitive measurement of minuscule forces such as those produced by an EMDrive.

One issue that could become a problem is air currents which could potentially give false positives. Once the frustum is set up on the fulcrum with a counterweight the fulcrum will be left for 10 minutes in the testing room. The setup will then be powered on for a burst of 10 seconds.

The frustum will be suspended in an upright position below the beam of the fulcrum. A laser will be attached to the other end of the beam which will project onto graph paper. This setup will detect any upwards or downwards forces on the frustum. A camera is positioned perpendicular to the graph paper to make measurements of the laser point.

One for example could say that the erratic oscillations are just due to convection currents in the air and unrelated to the EM Drive (as shown by the videos of rfmwguy).  Not way to know from this brief description.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 02:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415243#msg1415243">Quote from: TheTraveller on 08/11/2015 01:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415237#msg1415237">Quote from: Rodal on 08/11/2015 01:33 PM</a>
Calculation of resonant frequencies in cavities is well-known and established.  Has been replicated routinely in thousands of carefully designed experiments.  Routinely done at CERN and other particle accelerators using Finite Element Analysis . The hundreds of thousands of readers of this thread can conduct their own calculations based on the NASA dimensions (see attached NASA report for dimensions frequencies and mode shape) and independently verify whether the mode shape at 2.45 GHz is TM212 or TE212

As I said proof of the calc is seeing a S11 return loss dip at the calculated freq. Is easy to do. EW has the VNA to do the scan. So why no scans to back the calcs?
My limited experience with the comsol EM module is it works fine!
Without calculations it is difficult(not possible) to say a specific peak in the S-parameter plot is the target resonance. I am sure EW did both, calculations and measurements

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 02:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415249#msg1415249">Quote from: X_RaY on 08/11/2015 02:11 PM</a>
My limited experience with the comsol EM module is it works fine!
Without calculations it is difficult(not possible) to say a specific peak in the S-parameter plot is the target resonance.

Sure understand that. But if you do a scan on a cavity and the predicted resonance is not there, then what?

As far as I know, there were no scans to back up all the mode and freq calculations that EW did.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 02:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415247#msg1415247">Quote from: Rodal on 08/11/2015 02:00 PM</a>
I see the dimensions of the truncated cone there but I don't see enough details to do any modeling: no masses and most bothersome, no dimensions or description of the testing set-up except:

This info is in his report. How is this not enough info to do an analysis?

Hypothesis Test 1 – NASA cavity size at 2450MHz
When microwaves are supplied into the cavity, a thrust will be produced by the frustum.

Hypothesis Test 2 – Frustum extended by 50 mm excited at 2450MHz
When microwaves are supplied into the cavity, a greater thrust will be produced by the increase in resonance.

The specifications of the frustum are as follows
Height (perpendicular): 228 mm (1) 278mm (2)
Big Diameter: 279.4mm
Small Diameter: 158.8mm
Material: Copper
Antenna location: 34.29 mm from Big Diameter

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 02:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415252#msg1415252">Quote from: TheTraveller on 08/11/2015 02:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415247#msg1415247">Quote from: Rodal on 08/11/2015 02:00 PM</a>
I see the dimensions of the truncated cone there but I don't see enough details to do any modeling: no masses and most bothersome, no dimensions or description of the testing set-up except:

This info is in his report. How is this not enough info to do an analysis?

Hypothesis Test 1 – NASA cavity size at 2450MHz
When microwaves are supplied into the cavity, a thrust will be produced by the frustum.

Hypothesis Test 2 – Frustum extended by 50 mm excited at 2450MHz
When microwaves are supplied into the cavity, a greater thrust will be produced by the increase in resonance.

The specifications of the frustum are as follows
Height (perpendicular): 228 mm (1) 278mm (2)
Big Diameter: 279.4mm
Small Diameter: 158.8mm
Material: Copper
Antenna location: 34.29 mm from Big Diameter

Do you understand how to model the dynamic oscillations of the knife-edge fulcrum composed of a long balancing beam which rests on two razor edges ?  :)


You repeated the dimensions of the truncated cone, again, as I wrote:

Quote
I see the dimensions of the truncated cone there but I don't see enough details to do any modeling: no masses and most bothersome, no dimensions or description of the testing set-up except

no dimensions of the knife-edge fulcrum composed of a long balancing beam which rests on two razor edges
no masses

Is there even a photograph from which one can guesstimate dimensions of the "long balancing beam", etc.?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 02:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415255#msg1415255">Quote from: Rodal on 08/11/2015 02:24 PM</a>
Do you understand how to model the dynamic oscillations in a testing set-up ?

1st you need to confirm resonance. Last time that I remember you commented there was no resonance for the EW copper frustum at 2.45GHz. Might try that again and over the range +-30MHz.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 02:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415258#msg1415258">Quote from: TheTraveller on 08/11/2015 02:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415255#msg1415255">Quote from: Rodal on 08/11/2015 02:24 PM</a>
Do you understand how to model the dynamic oscillations in a testing set-up ?

1st you need to confirm resonance. Last time that I remember you commented there was no resonance for the EW copper frustum at 2.45GHz. Might try that again and over the range +-30MHz.
Sigh.  Hand over the discussion with TheTraveller of the South African experiment  to you deltaMass and Frobnicat ;)

PS: I never said that
Quote from: TheTraveller
there was no resonance for the EW copper frustum at 2.45GHz
that is a complete canard. 

I even gave the TM212 resonance frequencies to Mulletron for his NASA-dimensioned experiment at 2.45 GHz and put the Iulian Berca mode shape TM212 at 2.45GHz in the EM Drive wiki accordingly.

Unbelievable for TheTraveller to say such a canard.  I even submitted to his attention (and SeeShell quoted in one of her messages) a complete table, for all NASA calculated frequencies from below 1GHz to 2.5GHz comparing my exact solution results to NASA results including TM212 at 2.45Ghz

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/11/2015 02:33 PM
It becomes obvious that not every DIY builder has the same experience level of building experimental setups. By this I do not mean that there is a lack of experience on a technical skill-level, but on the data reporting...

Would it make sense to build some sort of checklist that would include all the needed required data, so that it can better assist those who work on a theoretical level?

Seeshell , fe, has many years of experience in building experimental devices, but not everybody is used to work in a scientific research environment and knows how to bring all their data.

Some guidelines for experimental reporting could help everybody, no?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 02:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415250#msg1415250">Quote from: TheTraveller on 08/11/2015 02:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415249#msg1415249">Quote from: X_RaY on 08/11/2015 02:11 PM</a>
My limited experience with the comsol EM module is it works fine!
Without calculations it is difficult(not possible) to say a specific peak in the S-parameter plot is the target resonance.

Sure understand that. But if you do a scan on a cavity and the predicted resonance is not there, then what?

As far as I know, there were no scans to back up all the mode and freq calculations that EW did.

I had this problem several times. Scan a larger bandwidth and you will find the modes not very far away. The problem is not the calculation (that works), the problems are imperfections in the builded cavity itself namy the dimensions, the antenna feed, the cavity material and so on. All that are systematic errors and causes frequency offsets to the calculated target frequencies.

I don't know why EW don't show these plots  ??? looks good in such a paper ;)

EDIT
Different calculation methods also leads to different Resultats (often only a few MHz).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/11/2015 02:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415207#msg1415207">Quote from: Chrochne on 08/11/2015 11:41 AM</a>
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

New EmDrive test results by PaulTheSwag posted few minutes ago on the reddit.
Interesting build, well documented. Would have liked to have seen some video. Seems like a similar setup to my fulcrum, which is all mechanical...eliminates sevaral digital variables. Nice use of solid copper. His extended fulcrum is similar to my nsf-1701. Feedpoint similat to spr and julians null point. Julian moved feedpoint halfway up frustum to get results. Congrats to his gold medal! That opens doors for further research for this young DIYer...bravo.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 02:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415250#msg1415250">Quote from: TheTraveller on 08/11/2015 02:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415249#msg1415249">Quote from: X_RaY on 08/11/2015 02:11 PM</a>
My limited experience with the comsol EM module is it works fine!
Without calculations it is difficult(not possible) to say a specific peak in the S-parameter plot is the target resonance.

Sure understand that. But if you do a scan on a cavity and the predicted resonance is not there, then what?

As far as I know, there were no scans to back up all the mode and freq calculations that EW did.
I have a simple VNA I plan to use to find resonance frequencies and it's simply a verification to the calculations. Over the years I know formulas are fine but deal in a virtual world and the calculated vs the real world seldom agree 100%. That's why the some of the waveguides are tuned with guys with tiny little hammers or with stub tuner screws.

Even NASA should have used VNAs in air and vacuum just to check and I'm not sure they did. 

Back to working and lurking.

shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/11/2015 02:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415261#msg1415261">Quote from: Flyby on 08/11/2015 02:33 PM</a>
It becomes obvious that not every DIY builder has the same experience level of building experimental setups. By this I do not mean that there is a lack of experience on a technical skill-level, but on the data reporting...

Would it make sense to build some sort of checklist that would include all the needed required data, so that it can better assist those who work on a theoretical level?

Seeshell , fe, has many years of experience in building experimental devices, but not everybody is used to work in a scientific research environment and knows how to bring all their data.

Some guidelines for experimental reporting could help everybody, no?

I second this and have also posted suggestions on additional standard test data that at this stage of testing EM Drives might be helpful to include or at least consider:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415202#msg1415202

At some point should there not be at least suggested test data result standards that all EM Drive builders could reference in the Wiki? Not mandating that they be used. But suggesting they should be.

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 02:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415265#msg1415265">Quote from: rfmwguy on 08/11/2015 02:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415207#msg1415207">Quote from: Chrochne on 08/11/2015 11:41 AM</a>
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

New EmDrive test results by PaulTheSwag posted few minutes ago on the reddit.
Interesting build, well documented. Would have liked to have seen some video. Seems like a similar setup to my fulcrum, which is all mechanical...eliminates sevaral digital variables. Nice use of solid copper. His extended fulcrum is similar to my nsf-1701. Feedpoint similat to spr and julians null point. Julian moved feedpoint halfway up frustum to get results. Congrats to his gold medal! That opens doors for further research for this young DIYer...bravo.
That does my heart wonders to see a young man tackel this. Good for him!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/11/2015 03:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415261#msg1415261">Quote from: Flyby on 08/11/2015 02:33 PM</a>
It becomes obvious that not every DIY builder has the same experience level of building experimental setups. By this I do not mean that there is a lack of experience on a technical skill-level, but on the data reporting...

Would it make sense to build some sort of checklist that would include all the needed required data, so that it can better assist those who work on a theoretical level?

Seeshell , fe, has many years of experience in building experimental devices, but not everybody is used to work in a scientific research environment and knows how to bring all their data.

Some guidelines for experimental reporting could help everybody, no?
I agree. I had mentioned a while ago that it would be nice to create a NI labview standard for all drives to tested against. We should think about the methods and data logging. From that point, we test at a single test bed. I think shell is well on her way to creating a standardized test facility. With that will come the need to develop standardized test software, sensors., et al.

Of course I have not asked shell if she's interested in becoming THE global test facility...;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 03:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415272#msg1415272">Quote from: rfmwguy on 08/11/2015 03:02 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415261#msg1415261">Quote from: Flyby on 08/11/2015 02:33 PM</a>
It becomes obvious that not every DIY builder has the same experience level of building experimental setups. By this I do not mean that there is a lack of experience on a technical skill-level, but on the data reporting...

Would it make sense to build some sort of checklist that would include all the needed required data, so that it can better assist those who work on a theoretical level?

Seeshell , fe, has many years of experience in building experimental devices, but not everybody is used to work in a scientific research environment and knows how to bring all their data.

Some guidelines for experimental reporting could help everybody, no?
I agree. I had mentioned a while ago that it would be nice to create a NI labview standard for all drives to tested against. We should think about the methods and data logging. From that point, we test at a single test bed. I think shell is well on her way to creating a standardized test facility. With that will come the need to develop standardized test software, sensors., et al.

Of course I have not asked shell if she's interested in becoming THE global test facility...;)
I might be up for it and I kind of like the idea. I cringe at the lack of safety used to get something to thrust and I see so many coming online right now. It's going to be desperately needed and standardized... but...

We're gonna need a bigger boat.
https://www.youtube.com/watch?v=QT9BeGNnCqw

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 03:31 PM
Apologies.

The mode I reported for the South African frustum as TE212 was actually TE213 as can be clearly seen on the screenshot.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 03:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415260#msg1415260">Quote from: Rodal on 08/11/2015 02:32 PM</a>
Unbelievable for TheTraveller to say such a canard.  I even submitted to his attention (and SeeShell quoted in one of her messages) a complete table, for all NASA calculated frequencies from below 1GHz to 2.5GHz comparing my exact solution results to NASA results including TM212 at 2.45Ghz

We were discussing the EW frustum and the lack of any 2.45GHz resonance in any mode, which we both agreed with. We both ending up suggested the EW copper frustum's length needed to be increased.

Remember or shall I dig it out? Trust me my memory is VERY good.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 03:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415285#msg1415285">Quote from: TheTraveller on 08/11/2015 03:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415260#msg1415260">Quote from: Rodal on 08/11/2015 02:32 PM</a>
Unbelievable for TheTraveller to say such a canard.  I even submitted to his attention (and SeeShell quoted in one of her messages) a complete table, for all NASA calculated frequencies from below 1GHz to 2.5GHz comparing my exact solution results to NASA results including TM212 at 2.45Ghz

We were discussing the EW frustum and the lack of any 2.45GHz resonance in any mode, which we both agreed with. We both ending up suggested the EW copper frustum's length needed to be increased.

Remember or shall I dig it out? Trust me my memory is VERY good.

That is a  canard.  For you to insist on these false accusations without even bothering to verify whether your long-term memory is correct, after you just had to apologize for your short-term memory confusion (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415282#msg1415282)  is just unfathomable :) .

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 03:41 PM
Does anyone have any experience with this?
http://www.amazon.com/ADXL345-Digital-Sensors-Acceleration-Arduino/dp/B008B4W1QS/ref=sr_1_2?s=automotive&ie=UTF8&qid=1439307463&sr=1-2&keywords=sensor+acceleration

Never mind I found a spec sheet on it.... thx

Just to log data for the stand... I'm liking the Pi

compass magnetometer IC, I2C, HMC5883L, PCB module, for Arduino microcontroller
http://www.gearbest.com/development-boards/pp_156161.html?currency=USD&gclid=CNLS1LCzoccCFQkFaQod43IBVg

http://www.gearbest.com/development-boards/pp_156161.html?currency=USD&gclid=CNLS1LCzoccCFQkFaQod43IBVg
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/11/2015 03:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415272#msg1415272">Quote from: rfmwguy on 08/11/2015 03:02 PM</a>
I had mentioned a while ago that it would be nice to create a NI labview standard for all drives to tested against.

Would it be possible to use:
http://www.myopenlab.de/startseite.html

Open source but simple, (too simple?)..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 04:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415288#msg1415288">Quote from: Rodal on 08/11/2015 03:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415285#msg1415285">Quote from: TheTraveller on 08/11/2015 03:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415260#msg1415260">Quote from: Rodal on 08/11/2015 02:32 PM</a>
Unbelievable for TheTraveller to say such a canard.  I even submitted to his attention (and SeeShell quoted in one of her messages) a complete table, for all NASA calculated frequencies from below 1GHz to 2.5GHz comparing my exact solution results to NASA results including TM212 at 2.45Ghz

We were discussing the EW frustum and the lack of any 2.45GHz resonance in any mode, which we both agreed with. We both ending up suggested the EW copper frustum's length needed to be increased.

Remember or shall I dig it out? Trust me my memory is VERY good.

That is a  canard.  For you to insist on these false accusations without even bothering to verify whether your long-term memory is correct, after you just had to apologize for your short-term memory confusion (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415282#msg1415282)  is just unfathomable.

As for my long term memory it is correct:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1390632#msg1390632

What about yours?

As for the mode confusion, we all make mistakes, shall I point out a few of yours?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/11/2015 04:13 PM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415272#msg1415272">Quote from: rfmwguy on 08/11/2015 03:02 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415261#msg1415261">Quote from: Flyby on 08/11/2015 02:33 PM</a>
It becomes obvious that not every DIY builder has the same experience level of building experimental setups. By this I do not mean that there is a lack of experience on a technical skill-level, but on the data reporting...

Would it make sense to build some sort of checklist that would include all the needed required data, so that it can better assist those who work on a theoretical level?

Seeshell , fe, has many years of experience in building experimental devices, but not everybody is used to work in a scientific research environment and knows how to bring all their data.

Some guidelines for experimental reporting could help everybody, no?
I agree. I had mentioned a while ago that it would be nice to create a NI labview standard for all drives to tested against. We should think about the methods and data logging. From that point, we test at a single test bed. I think shell is well on her way to creating a standardized test facility. With that will come the need to develop standardized test software, sensors., et al.

Of course I have not asked shell if she's interested in becoming THE global test facility...;)

I regard your work & Shell's as being the high bar that other DIY builders should aspire too.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 04:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415293#msg1415293">Quote from: OttO on 08/11/2015 03:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415272#msg1415272">Quote from: rfmwguy on 08/11/2015 03:02 PM</a>
I had mentioned a while ago that it would be nice to create a NI labview standard for all drives to tested against.

Would it be possible to use:
http://www.myopenlab.de/startseite.html

Open source but simple, (too simple?)..

Not a  bad thought, it is a little simple but somewhat unknown for many. Maybe we can still use Wiki but setup a spread sheet layout with most of the information and a link to more detailed data. I know every test will not use or need some of the data points.

I've just ordered magnetic compass detectors and acceleration detectors on the fulcrum beam. Not extremely sensitive stuff, but it will give some needed baseline data. I'll also be recording date, time, temp, humidity of the lab.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 04:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415297#msg1415297">Quote from: TheTraveller on 08/11/2015 04:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415288#msg1415288">Quote from: Rodal on 08/11/2015 03:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415285#msg1415285">Quote from: TheTraveller on 08/11/2015 03:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415260#msg1415260">Quote from: Rodal on 08/11/2015 02:32 PM</a>
Unbelievable for TheTraveller to say such a canard.  I even submitted to his attention (and SeeShell quoted in one of her messages) a complete table, for all NASA calculated frequencies from below 1GHz to 2.5GHz comparing my exact solution results to NASA results including TM212 at 2.45Ghz

We were discussing the EW frustum and the lack of any 2.45GHz resonance in any mode, which we both agreed with. We both ending up suggested the EW copper frustum's length needed to be increased.

Remember or shall I dig it out? Trust me my memory is VERY good.

That is a  canard.  For you to insist on these false accusations without even bothering to verify whether your long-term memory is correct, after you just had to apologize for your short-term memory confusion (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415282#msg1415282)  is just unfathomable.

As for my long term memory it is correct:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1390632#msg1390632

What about yours?

As for the mode confusion, we all make mistakes, shall I point out a few of yours?

There is something wrong with your comprehension:

1)The quotation you provide is NOT for the NASA dimensions it is for RFMwguy dimensions
2) In the quotation you provide I explicitly say that there is no such thing as "no resonance" because of mode participation at these frequencies, the complete opposite of what you claim

Quote from: Rodal
Sorry, I don't agree with the word "will not resonate" in absolute terms.  You probably mean "will not resonate at the highest Q".  There is always a spectral response of resonance, which will contains peaks with different amplitude at different frequencies. 

3) I never stated "will not resonate".  You are the one that stated that, and I explicitly answered that I did not agree with you.

4) There are many frequencies in the spectrum around 2.45 GHz for NASA and for RFMWguy.  I would never state "not resonate" it is just a matter of what modes will participate the most.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 04:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415299#msg1415299">Quote from: Star One on 08/11/2015 04:13 PM</a>

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415272#msg1415272">Quote from: rfmwguy on 08/11/2015 03:02 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415261#msg1415261">Quote from: Flyby on 08/11/2015 02:33 PM</a>
It becomes obvious that not every DIY builder has the same experience level of building experimental setups. By this I do not mean that there is a lack of experience on a technical skill-level, but on the data reporting...

Would it make sense to build some sort of checklist that would include all the needed required data, so that it can better assist those who work on a theoretical level?

Seeshell , fe, has many years of experience in building experimental devices, but not everybody is used to work in a scientific research environment and knows how to bring all their data.

Some guidelines for experimental reporting could help everybody, no?
I agree. I had mentioned a while ago that it would be nice to create a NI labview standard for all drives to tested against. We should think about the methods and data logging. From that point, we test at a single test bed. I think shell is well on her way to creating a standardized test facility. With that will come the need to develop standardized test software, sensors., et al.

Of course I have not asked shell if she's interested in becoming THE global test facility...;)

I regard your work & Shell's as being the high bar that other DIY builders should aspire too.
That's the nicest thing someone has said in a long time. I'm flattered and thank you.

Added: I think I'd like rfmwguy do the narration on my tests. I'll send you a script rfmwguy. ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 04:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415301#msg1415301">Quote from: Rodal on 08/11/2015 04:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415297#msg1415297">Quote from: TheTraveller on 08/11/2015 04:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415288#msg1415288">Quote from: Rodal on 08/11/2015 03:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415285#msg1415285">Quote from: TheTraveller on 08/11/2015 03:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415260#msg1415260">Quote from: Rodal on 08/11/2015 02:32 PM</a>
Unbelievable for TheTraveller to say such a canard.  I even submitted to his attention (and SeeShell quoted in one of her messages) a complete table, for all NASA calculated frequencies from below 1GHz to 2.5GHz comparing my exact solution results to NASA results including TM212 at 2.45Ghz

We were discussing the EW frustum and the lack of any 2.45GHz resonance in any mode, which we both agreed with. We both ending up suggested the EW copper frustum's length needed to be increased.

Remember or shall I dig it out? Trust me my memory is VERY good.

That is a  canard.  For you to insist on these false accusations without even bothering to verify whether your long-term memory is correct, after you just had to apologize for your short-term memory confusion (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415282#msg1415282)  is just unfathomable.

As for my long term memory it is correct:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1390632#msg1390632

What about yours?

As for the mode confusion, we all make mistakes, shall I point out a few of yours?

You are either very confused or there is something very wrong with you insisting with this canard:

1) The quotation you provide is NOT for the NASA dimensions it is for RFMwguy dimensions
2) In the quotation you provide I explicitly say that there is no such thing as "no resonance" because of mode participation at these frequencies, the complete opposite of what you claim

Quote from: Rodal
Sorry, I don't agree with the word "will not resonate" in absolute terms.  You probably mean "will not resonate at the highest Q".  There is always a spectral response of resonance, which will contains peaks with different amplitude at different frequencies. 

3) I never stated "will not resonate".  You are the one that stated that, and I explicitly answered that I did not agree with you.

The frustum dimensions quoted are for the copper EW frustum as the post clearly says.

Quote
At least Dr Rodal and I agree the standard EW frustum

Frustum big diameter    m   0.2794000
Frustum small diameter   m   0.1588000
Frustum centre length   m   0.2286000
External Rf                   Hz   2,450,000,000

will not resonate at 2.45GHz.

What you said was while there were no high Q resonances at 2.45GHz, there may be low Q resonances, even though you gave no proof that there were any low Q resonances around 2.45GHz. Which there are not.

Point is we both agreed the EW frustum length needed to be increased and following that advise RFMwguy increased his frustum length.

So please now show me any modes that resonant at 2.45GHz with the EW copper frustum. If you can't then thanks for the verification that we agree there are no resonant modes at 2.45GHz for the EW frustum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 04:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415305#msg1415305">Quote from: TheTraveller on 08/11/2015 04:26 PM</a>
...

Point is we both agreed the EW frustum length needed to be increased and following that advise RFMwguy increased his frustum length.

So please now show me any modes that resonant at 2.45GHz with the EW copper frustum. If you can't then thanks for the verification that we agree there are no resonant modes at 2.45GHz for the EW frustum.

As I said before :

Quote from: Rodal
Sorry, I don't agree with the word "will not resonate" in absolute terms.  You probably mean "will not resonate at the highest Q".  There is always a spectral response of resonance, which will contains peaks with different amplitude at different frequencies. 

I didn't agree with you then, and I don't agree with you now. Period.  Case in point: the recent Meep runs showing mode participation from different modes.  Nothing unusual about that..  :)

The only mode shape that has ever been verified for an EM Drive has been TM212 for NASA with a dielectric insert that matched TM212 NASA prediction at 1.94GHz.  NASA predicts TM212 at 2.45GHz with the NASA dimensions and no dielectric. (It is well known that dielectric insert lower the natural frequency of a mode shape)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=36313.0,3Battach=846719,3Bimage.pagespeed.ic.KVIUQGgNKt.webp)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 04:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415308#msg1415308">Quote from: Rodal on 08/11/2015 04:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415305#msg1415305">Quote from: TheTraveller on 08/11/2015 04:26 PM</a>
...

Point is we both agreed the EW frustum length needed to be increased and following that advise RFMwguy increased his frustum length.

So please now show me any modes that resonant at 2.45GHz with the EW copper frustum. If you can't then thanks for the verification that we agree there are no resonant modes at 2.45GHz for the EW frustum.

As I said before :

Quote from: Rodal
Sorry, I don't agree with the word "will not resonate" in absolute terms.  You probably mean "will not resonate at the highest Q".  There is always a spectral response of resonance, which will contains peaks with different amplitude at different frequencies. 

I didn't agree with you then, and I don't agree with you now. Period. 

As I said in a previous e-mail I don't plan to ever spend any time showing you anything.

Which say to me your exact solution can't predict the resonance mode for:

1) The Flight Thruster

2) The EW frustum

3) The SA replication of the EW frustum

4) The Tajmar frustum

5) The Iulian frustum

So of what value is a exact solution that can't match real world data.

Should add your exact solution for my frustum design, that was verified by the latest SPR design software, was so far off as to again show your so called "exact solution" is far from exact.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/11/2015 04:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415308#msg1415308">Quote from: Rodal on 08/11/2015 04:36 PM</a>
The only mode shape that has ever been verified for an EM Drive has been TM212 for NASA with a dielectric that matched TM212 NASA prediction.  NASA predicts TM212 at 2.45GHz with the NASA dimensions.

And that is working well for them?

Getting lots of Force generation in atmo and vac are they?

BTW, the EW copper frustum is operating in a claimed TM212 mode at 1.937GHz and not at 2.45GHz.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 05:09 PM
Here are the two png sets scaled to the maximum range of the E and H fields for the t=0 time slice. The ranges are from field components as follows:

# ez all data range from -0.000245405 to 0.000245405.     E field big end
# hx all data range from -0.000538633 to 0.000538633.     H field big end
# ez all data range from -4.04811e-05 to 4.04811e-05.     E field small end
# hy all data range from -0.000287974 to 0.000287974.     H field small end


Please look these png's over closely to be sure that this is what you want to see as it will be considerable effort to scale the png files in this way for the general case.

Or do you need to see the side views for this t = 0 case?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 05:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315">Quote from: aero on 08/11/2015 05:09 PM</a>
Here are the two png sets scaled to the maximum range of the E and H fields for the t=0 time slice. The ranges are from field components as follows:

# ez all data range from -0.000245405 to 0.000245405.     E field big end
# hx all data range from -0.000538633 to 0.000538633.     H field big end
# ez all data range from -4.04811e-05 to 4.04811e-05.     E field small end
# hy all data range from -0.000287974 to 0.000287974.     H field small end


Please look these png's over closely to be sure that this is what you want to see as it will be considerable effort to scale the png files in this way for the general case.

Or do you need to see the side views for this t = 0 case?

Thank you for going through the trouble to do this.

1) Assuming that the longitudinal axis is the z axis, this looks indeed like a TE mode (transverse electric) as the Hz mode (magnetic field in the longitudinal direction) is strong and the Ez (electric field in the longitudinal direction) is weak

however...

2) The blue areas in the fields: they look like the magnitude has been clipped. 

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055383,3Bimage.pagespeed.ic.hjMMacoPKv.webp)

They look like ContourPlots in Mathematica when I use PlotRange with a range smaller than the full magnitude, so the contours get cliped.  I would double check whether magnitudes have not been clipped. 

3) Is there some means to control the number of contour values in the contour plots?  It looks to me like there are more contour levels than the number of colors available, as a result colors keep repeating themselves.  What one wants is to have blue represent the lowest magnitude and red the highest magnitude, instead of red/green/blue/yellow patterns being repeated cyclically.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055381,3Bimage.pagespeed.ic.p_0CAdsbWT.webp)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/11/2015 06:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415150#msg1415150">Quote from: aero on 08/11/2015 04:15 AM</a>

The numerical field intensity values may be available in some convenient way that I just don't know about, but I have looked. Other meepers looking would be very helpful.

They are available, just not convenienly, by using the "-verbose" switch on h5topng. Unfortunately, using that will require two separate runs, but I guess any method would require two separate runs at some level. Here is the verbose output from generating one png file.

Quote
steve@steve-p6720f:~$ h5topng -v -t 0  -z 214 ./Shell-2-d-dipole-loop-out/hx.h5
Using colormap "gray" in file "/usr/share/h5utils/colormaps/gray".
grayscale color map (white to black)
2 color entries read from colormap file.
Scaling opacity by 1
data rank = 4
------
reading from "./Shell-2-d-dipole-loop-out/hx.h5", slice at 214 in z dimension, slice at 0 in t dimension.
data ranges from -0.00012754 to 0.00012754.
writing "./Shell-2-d-dipole-loop-out/hx.png" from 196x196 input data.
all data range from -0.00012754 to 0.00012754.

I manually made 12 runs of h5topng, and extracted the following data ranges.

Range of data values in Shell-2-d-dipole-loop64-out

slice t 00, z 15 Big end
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.

hx all data range from -0.000538633 to 0.000538633.
hy all data range from -0.000356036 to 0.000356036.
hz all data range from -4.65749e-05 to 3.78542e-05.

slice t 00 z 214 Small end
ex all data range from -1.60461e-05 to 1.60461e-05.
ey all data range from -3.20985e-05 to 3.20985e-05.
ez all data range from -4.04811e-05 to 4.04811e-05.

hx all data range from -0.00012754 to 0.00012754.
hy all data range from -0.000287974 to 0.000287974.
hz all data range from -1.07156e-05 to 1.61666e-05.


As I understand you, what you need is to have three png files, ex, ey, ez scaled to the maximum range of the E components and three, hx hy, hz scaled to the maximum range for the H component - for each time slice and each of the 4 geometry slices per time slice. That would be the ez range and the hx range for the first case above, but note that max value and min value won't necessarily always be from the same component as the second hz range above indicates.

Scaling the range of values using this approach is quite unwieldy to do manually, as there are I believe 336 pngs for a standard data set as I have been using, but also, we might benefit by extending that data set to 2 full cycles, or even more.

Does anyone here want to volunteer to create a bash shell file that runs the data set in verbose mode capturing the terminal output in the log file, then scan that log file, extract the correct range of values and scale the h5topng max and min switches, then run the data set again for upload?  Conceptually it should be straight forward but I only recognize bash in passing, are almost strangers. Of course one could use Octave or MatLab to read the log file and extract the pertinent data, or even write a purpose program that simply scans and extracts the data then writes a new shell file with as many h5topng command lines as needed. That might be safer and the 336 + command line shell file would be "throw away" so it wouldn't need to be "slick."

Please find attached a simple python program.  Rename to h5topng_range.py.  Usage:

python h5topng_range.py --logfile filename.txt

Output is to stdout, so some post processing will be necessary to get this to run in bash (I'm on windows, no access to bash until tonight).  Tested with version 3.x should work with 2.5+ but I haven't tested.  Uses the argparse library which is standard in version 3.x.

For the sample h5topng output quoted above, contained in "filename.txt", this produces the output:

h5topng -t 0 -z 214 -m -0.00012754 -M 0.00012754 ./Shell-2-d-dipole-loop-out/hx.h5

The numbers are pulled from the "all range data from" line and not the "data ranges from" line.  The "-z" switch is parametric based on the "reading from" line.  The "-t" is hardcoded, but can be made parametric if necessary, the value after "-t" is, of course, parametric.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 07:04 PM
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 07:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/11/2015 07:15 PM
Ok since the photons inside the cavity are traveling in a medium at a group velocity <c, we can technically define a frame where the photon is at rest relative to the cavity walls. I can't justify a reason to not treat them as massive particles in calculations.

This is a special case since we're not dealing with photons in vacuum. Does this sound controversial to anyone? That means switching to relativistic momentum.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html

This ref was shared by someone else recently and I think it is significant.

http://arxiv.org/abs/0708.3519
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 07:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 07:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
Nah - viel zu langsam.
Do you have a helpful answer?
Ich denke es ist dieses Teil auf dem Foto ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 07:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415216#msg1415216">Quote from: Rodal on 08/11/2015 12:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415145#msg1415145">Quote from: Rodal on 08/11/2015 03:40 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415126#msg1415126">Quote from: Ricvil on 08/11/2015 01:40 AM</a>

Dr Rodal, I think there is a problem again.
Standing waves.
In the cavity, at least,  the fields are superpositions of two counter propagating waves, then one has (to simplify)
E=[a.exp(gamma.r)+b.exp(-gamma.r)].F(tetha,phi)
Repair, the expression above is just a aproximate model to fit the fields by exponential functions, where the correct is to use fractional spherical hankel functions (for spherical ends cavitys), where a,b and gamma will fataly be functions of r. At r>>1 the spherical  hankel function decay with 1/r.
Then how to differentiate a destructive interference at node fields from a infinity attenuation?
Worse, even with a,b and gamma being constants, when one take the derivative of E above, because the two signals of gamma (outward/inward from/to apex cone) one has
dE/dr=gamma[a.exp(gamma.r) -b.exp(-gamma.r)].F(theta,phi), and we lost original E function, then imagine with a,b and gamma being r functions.

This is just my way to think. You may, of course, disagree. :)

There is NO approximation, and there is no fitting.  There is NO exponential fit, because γ is not a constant here, γ is a function of r, defined to give the identical part of Eθ that is solely expressible in term of r .  The meaning of γ is only as described by the mathematical expression, not more and not less.

γ is not a closed-form expression, it is not expressible by any known function known in any text.  γ is given by Wolfram Mathematica as the solution of the differential equation, it is NOT a known classical function, it is NOT an exponential with a constant exponent multiplying r.

It is just a mapping of the original function into another function that gives exactly the same result.

It is exactly the same. 

The solution Eθ in terms of γ exponential and A is identical to the one expressed in terms of Spherical Bessel functions and the Legendre Associated functions, it is just expressed in a different form. 

Tomorrow I will post a comparison plot to show this identity.  It is identical by construction

/////////////////////////////////////////////////////////////////

As to interference, separate waves and other issues present in the transient when the RF feed is ON, I have not dealt with those aspects. I have only dealt with the standing wave solution. To deal with the transient with the RF feed ON, yes I would have to use Hankel functions.

As promised, I attach a plot showing that the result of exponentiating the gamma function γ I derived (times -r)

Eθ = A e - γ r

results in exactly the same function as the exact electric field Eθ divided by A: Eθ /A.  There is no approximation. 

Again, this is by construction.  The gamma function γ(r) cannot be expressed in terms of any known function appearing in any textbook, it has to be obtained as a numerical solution to the differential equation:

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

By contrast, the γ function as defined by Zeng and Fan (who define it as  γ = - (1/Eθ)*dEθ/dr )
does not result in Eθ / A = e - γ r as is easy to show.  See the bottom attached image, showing divergence at small radius near the small base.

A plot of what proper definition of the gamma function γ(r) looks like is shown here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415088#msg1415088

We continue this discussion now with the TE012 mode of Yang/Shell.

Unfortunately for TEmnp mode shapes with p>1 we encounter the problem that Ricvl was discussing:

1) γ is positive whether Eθ is positive or negative.  The sign (whether + or - ) of Eθ is lost upon computation of γ(r)  as a solution of

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

because the sign of Eθ appears both in the numerator and the denominator of the right hand side, hence it cancels out, and it gets lost unless we account for it. 
Therefore we can calculate γ(r) accurately, but upon substitution in 

A e - γ r

we have to account for whether the value corresponds to positive or negative values of the half wave-pattern of  Eθ.  This is similar to inverse functions that lose track of sign information (for example the Square Root function).  It is not a problem in computing γ(r), it is just a problem in inverting (which is not required) to verify that it corresponds to Eθ.

2) When p>1, we have more than one half wave-pattern to match, normalization is more elaborate:

a) we normalize the maximum of the maximum half-wave pattern to one.
b) we scale the lower value of the maximum of the other half-wave pattern as follows:
Ln[-(lower max half-wave pattern)/(max half-wave pattern)]/r (of lower max half-wave pattern)

We show below what γ(r) looks like using this scaling. We also show the Electric Field wave patterns for TE011 and TE012.

Both issues perhaps can be addressed by using Hankel functions and then taking Eθ as the real part.  We will investigate this in the future.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 07:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415319#msg1415319">Quote from: Rodal on 08/11/2015 05:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315">Quote from: aero on 08/11/2015 05:09 PM</a>
Here are the two png sets scaled to the maximum range of the E and H fields for the t=0 time slice. The ranges are from field components as follows:

# ez all data range from -0.000245405 to 0.000245405.     E field big end
# hx all data range from -0.000538633 to 0.000538633.     H field big end
# ez all data range from -4.04811e-05 to 4.04811e-05.     E field small end
# hy all data range from -0.000287974 to 0.000287974.     H field small end


Please look these png's over closely to be sure that this is what you want to see as it will be considerable effort to scale the png files in this way for the general case.

Or do you need to see the side views for this t = 0 case?

Thank you for going through the trouble to do this.

1) Assuming that the longitudinal axis is the z axis, this looks indeed like a TE mode (transverse electric) as the Hz mode (magnetic field in the longitudinal direction) is strong and the Ez (electric field in the longitudinal direction) is weak

however...

2) The blue areas in the fields: they look like the magnitude has been clipped. 

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055383,3Bimage.pagespeed.ic.hjMMacoPKv.webp)

They look like ContourPlots in Mathematica when I use PlotRange with a range smaller than the full magnitude, so the contours get cliped.  I would double check whether magnitudes have not been clipped. 

3) Is there some means to control the number of contour values in the contour plots?  It looks to me like there are more contour levels than the number of colors available, as a result colors keep repeating themselves.  What one wants is to have blue represent the lowest magnitude and red the highest magnitude, instead of red/green/blue/yellow patterns being repeated cyclically.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055381,3Bimage.pagespeed.ic.p_0CAdsbWT.webp)
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.


Of course they have been clipped.  Look at the data ranges for the three E field components. Anything below the data range (or above, but that won't happen) are well ....from the manual:  "Data values below or above this range will be treated as if they were min or max respectively." I suppose I could use the range from the minimum of the field  to the maximum. Not minimum/ maximum of the most energetic component. To do so would be only a little more difficult, but would that be better? I can't guess without looking.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 07:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415346#msg1415346">Quote from: aero on 08/11/2015 07:28 PM</a>
...
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.


Of course they have been clipped.  Look at the data ranges for the three E field components. Anything below the data range (or above, but that won't happen) are well ....from the manual:  "Data values below or above this range will be treated as if they were min or max respectively." I suppose I could use the range from the minimum of the field  to the maximum. Not minimum/ maximum of the most energetic component. To do so would be only a little more difficult, but would that be better? I can't guess without looking.
Yes, it would be better to have everything under


Electric field with highest absolute magnitude Universal Minimum /
Electric field with highest absolute magnitude Universal Maximum

for the electric fields

and

Magnetizing field with highest absolute magnitude Universal Minimum /
Magnetizing field with highest absolute magnitude Universal Maximum

because the Universal Min/Max doesn't discriminate based on sign of the field.

Since the values in the pictures are clipped, does that mean that the mode is really TM because what is shown is the minimum range instead of the maximum universal range? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 07:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415344#msg1415344">Quote from: X_RaY on 08/11/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
Nah - viel zu langsam.
Do you have a helpful answer?
Ich denke es ist dieses Teil auf dem Foto ;)

Danke Ihnen so sehr für dieses Foto :)

I had missed it

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 07:42 PM
How about my other two questions - the power? and why not just an impulse?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 08/11/2015 07:50 PM
I missed this post. https://hackaday.io/project/5596-em-drive/log/22182-silver-hires-print

It is really wonderful to see how many people are working on their own EmDrive.

NASA EW guys join the fray please  ;) That is if they let you....One post would not kill you you know and it can inspire more people.

Also storm after Prof. Tajmar first paper calmed down, but EmDrive now have more attention than before.
By the way any idea if Prof. Tajmar listens to this forum? It would be great to try to invite him here. His ideas and knowledge would be great addition here and can further boost incredible share of ideas here.
Maybe send an email signed by our science people here? :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 07:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415351#msg1415351">Quote from: deltaMass on 08/11/2015 07:42 PM</a>
How about my other two questions - the power? and why not just an impulse?
I can't give you a answer, but ask him self :)
Here is the report of this young guy...

Source: https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

Pictures can be load from:  http://imgur.com/a/iO7er
in a .zip file

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 07:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?
Quote
57n4rP7.jpg
double edge knife

And here is his report
https://docs.google.com/document/d/10uC31t-fb6sGAouICB1x7wF3F17qcBO5oie5_07Ethk/edit?pli=1

Links to it all.
https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 08:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415346#msg1415346">Quote from: aero on 08/11/2015 07:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415319#msg1415319">Quote from: Rodal on 08/11/2015 05:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315">Quote from: aero on 08/11/2015 05:09 PM</a>
Here are the two png sets scaled to the maximum range of the E and H fields for the t=0 time slice. The ranges are from field components as follows:

# ez all data range from -0.000245405 to 0.000245405.     E field big end
# hx all data range from -0.000538633 to 0.000538633.     H field big end
# ez all data range from -4.04811e-05 to 4.04811e-05.     E field small end
# hy all data range from -0.000287974 to 0.000287974.     H field small end


Please look these png's over closely to be sure that this is what you want to see as it will be considerable effort to scale the png files in this way for the general case.

Or do you need to see the side views for this t = 0 case?

Thank you for going through the trouble to do this.

1) Assuming that the longitudinal axis is the z axis, this looks indeed like a TE mode (transverse electric) as the Hz mode (magnetic field in the longitudinal direction) is strong and the Ez (electric field in the longitudinal direction) is weak

however...

2) The blue areas in the fields: they look like the magnitude has been clipped. 

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055383,3Bimage.pagespeed.ic.hjMMacoPKv.webp)

They look like ContourPlots in Mathematica when I use PlotRange with a range smaller than the full magnitude, so the contours get cliped.  I would double check whether magnitudes have not been clipped. 

3) Is there some means to control the number of contour values in the contour plots?  It looks to me like there are more contour levels than the number of colors available, as a result colors keep repeating themselves.  What one wants is to have blue represent the lowest magnitude and red the highest magnitude, instead of red/green/blue/yellow patterns being repeated cyclically.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055381,3Bimage.pagespeed.ic.p_0CAdsbWT.webp)
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.


Of course they have been clipped.  Look at the data ranges for the three E field components. Anything below the data range (or above, but that won't happen) are well ....from the manual:  "Data values below or above this range will be treated as if they were min or max respectively." I suppose I could use the range from the minimum of the field  to the maximum. Not minimum/ maximum of the most energetic component. To do so would be only a little more difficult, but would that be better? I can't guess without looking.

I have a silly question. If the data values are clipped why am I still seeing artifacts on the side walls?

shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 08:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415338#msg1415338">Quote from: lmbfan on 08/11/2015 06:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415150#msg1415150">Quote from: aero on 08/11/2015 04:15 AM</a>

The numerical field intensity values may be available in some convenient way that I just don't know about, but I have looked. Other meepers looking would be very helpful.

They are available, just not convenienly, by using the "-verbose" switch on h5topng. Unfortunately, using that will require two separate runs, but I guess any method would require two separate runs at some level. Here is the verbose output from generating one png file.

Quote
steve@steve-p6720f:~$ h5topng -v -t 0  -z 214 ./Shell-2-d-dipole-loop-out/hx.h5
Using colormap "gray" in file "/usr/share/h5utils/colormaps/gray".
grayscale color map (white to black)
2 color entries read from colormap file.
Scaling opacity by 1
data rank = 4
------
reading from "./Shell-2-d-dipole-loop-out/hx.h5", slice at 214 in z dimension, slice at 0 in t dimension.
data ranges from -0.00012754 to 0.00012754.
writing "./Shell-2-d-dipole-loop-out/hx.png" from 196x196 input data.
all data range from -0.00012754 to 0.00012754.

I manually made 12 runs of h5topng, and extracted the following data ranges.

Range of data values in Shell-2-d-dipole-loop64-out

slice t 00, z 15 Big end
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.

hx all data range from -0.000538633 to 0.000538633.
hy all data range from -0.000356036 to 0.000356036.
hz all data range from -4.65749e-05 to 3.78542e-05.

slice t 00 z 214 Small end
ex all data range from -1.60461e-05 to 1.60461e-05.
ey all data range from -3.20985e-05 to 3.20985e-05.
ez all data range from -4.04811e-05 to 4.04811e-05.

hx all data range from -0.00012754 to 0.00012754.
hy all data range from -0.000287974 to 0.000287974.
hz all data range from -1.07156e-05 to 1.61666e-05.


As I understand you, what you need is to have three png files, ex, ey, ez scaled to the maximum range of the E components and three, hx hy, hz scaled to the maximum range for the H component - for each time slice and each of the 4 geometry slices per time slice. That would be the ez range and the hx range for the first case above, but note that max value and min value won't necessarily always be from the same component as the second hz range above indicates.

Scaling the range of values using this approach is quite unwieldy to do manually, as there are I believe 336 pngs for a standard data set as I have been using, but also, we might benefit by extending that data set to 2 full cycles, or even more.

Does anyone here want to volunteer to create a bash shell file that runs the data set in verbose mode capturing the terminal output in the log file, then scan that log file, extract the correct range of values and scale the h5topng max and min switches, then run the data set again for upload?  Conceptually it should be straight forward but I only recognize bash in passing, are almost strangers. Of course one could use Octave or MatLab to read the log file and extract the pertinent data, or even write a purpose program that simply scans and extracts the data then writes a new shell file with as many h5topng command lines as needed. That might be safer and the 336 + command line shell file would be "throw away" so it wouldn't need to be "slick."

Please find attached a simple python program.  Rename to h5topng_range.py.  Usage:

python h5topng_range.py --logfile filename.txt

Output is to stdout, so some post processing will be necessary to get this to run in bash (I'm on windows, no access to bash until tonight).  Tested with version 3.x should work with 2.5+ but I haven't tested.  Uses the argparse library which is standard in version 3.x.

For the sample h5topng output quoted above, contained in "filename.txt", this produces the output:

h5topng -t 0 -z 214 -m -0.00012754 -M 0.00012754 ./Shell-2-d-dipole-loop-out/hx.h5

The numbers are pulled from the "all range data from" line and not the "data ranges from" line.  The "-z" switch is parametric based on the "reading from" line.  The "-t" is hardcoded, but can be made parametric if necessary, the value after "-t" is, of course, parametric.

That looks very promising.
No, the -t is what it is, the -x -y and -z are parameters, (one set per png file). But it looks like the shell file will need to undergo major changes. I've attached my shell file (change the extension to .sh). It works for what I have been doing but I am forced by h5topng to copy the .png files into the sub-folders from the -out folder. The new desire to set min/max for each value of t, x, y, z will force us to discard this approach and adopt a naming convention something like I use for the csv files. That shell file is also attached (changed extension) but h5totxt handles the sub-directory correctly so no file moving is needed.

As for running it in bash? Not necessary until the h5topng commands are fully formulated and written to a shell file. You can do all of that in Python if that is your language of choice. Then run that shell file in bash.

You will likely need to create a set of h5 files to run your tests against. Don't go to to much work until you do that because I'm not sure that the single case of data that I generated and posted is representative of what h5topng outputs when multiple files are generated. It's sure not what the attached shell file logs, but then, the attached is probably not representative of the ultimate design, either.

and see the manual, it's short:
http://ab-initio.mit.edu/h5utils/h5topng-man.html (http://ab-initio.mit.edu/h5utils/h5topng-man.html)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 08:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415357#msg1415357">Quote from: SeeShells on 08/11/2015 08:02 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415346#msg1415346">Quote from: aero on 08/11/2015 07:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415319#msg1415319">Quote from: Rodal on 08/11/2015 05:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315">Quote from: aero on 08/11/2015 05:09 PM</a>
Here are the two png sets scaled to the maximum range of the E and H fields for the t=0 time slice. The ranges are from field components as follows:

# ez all data range from -0.000245405 to 0.000245405.     E field big end
# hx all data range from -0.000538633 to 0.000538633.     H field big end
# ez all data range from -4.04811e-05 to 4.04811e-05.     E field small end
# hy all data range from -0.000287974 to 0.000287974.     H field small end


Please look these png's over closely to be sure that this is what you want to see as it will be considerable effort to scale the png files in this way for the general case.

Or do you need to see the side views for this t = 0 case?

Thank you for going through the trouble to do this.

1) Assuming that the longitudinal axis is the z axis, this looks indeed like a TE mode (transverse electric) as the Hz mode (magnetic field in the longitudinal direction) is strong and the Ez (electric field in the longitudinal direction) is weak

however...

2) The blue areas in the fields: they look like the magnitude has been clipped. 

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055383,3Bimage.pagespeed.ic.hjMMacoPKv.webp)

They look like ContourPlots in Mathematica when I use PlotRange with a range smaller than the full magnitude, so the contours get cliped.  I would double check whether magnitudes have not been clipped. 

3) Is there some means to control the number of contour values in the contour plots?  It looks to me like there are more contour levels than the number of colors available, as a result colors keep repeating themselves.  What one wants is to have blue represent the lowest magnitude and red the highest magnitude, instead of red/green/blue/yellow patterns being repeated cyclically.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055381,3Bimage.pagespeed.ic.p_0CAdsbWT.webp)
ex all data range from -3.67269e-05 to 3.67269e-05.
ey all data range from -1.42517e-05 to 1.42517e-05.
ez all data range from -0.000245405 to 0.000245405.


Of course they have been clipped.  Look at the data ranges for the three E field components. Anything below the data range (or above, but that won't happen) are well ....from the manual:  "Data values below or above this range will be treated as if they were min or max respectively." I suppose I could use the range from the minimum of the field  to the maximum. Not minimum/ maximum of the most energetic component. To do so would be only a little more difficult, but would that be better? I can't guess without looking.

I have a silly question. If the data values are clipped why am I still seeing artifacts on the side walls?

shell
Maybe artefacts from the grid but there are strong currents in the wall and corresponding fields...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 08:37 PM
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 08:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.
Today (morning) someone pointed out that it may be helpful to use a logarithmic scale, did you try that in the actual case? (one try to compare with the mag. scale?)
Other color map for the mag. scale like you sad could be also helpful i think.

BTW: great work, thanks for spend your time!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 08:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.

bluered (opaque blue to transparent white to opaque red). I have several color maps available, this is just the first try. I personally don't like it very much.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/11/2015 09:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415365#msg1415365">Quote from: X_RaY on 08/11/2015 08:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.
Today (morning) someone pointed out that it may be helpful to use a logarithmic scale, did you try that in the actual case? (one try to compare with the mag. scale?)
Other color map for the mag. scale like you sad could be also helpful i think.

BTW: great work, thanks for spend your time!
I saw that and frankly it gave me a nice chuckle. Two points on a log scale?

See: http://ab-initio.mit.edu/h5utils/h5topng-man.html (http://ab-initio.mit.edu/h5utils/h5topng-man.html) Look really, really closely for the log scale output, then tell me what you find.
Or maybe it would be more fruitful to look here: http://www.hdfgroup.org/products/java/hdfview/UsersGuide/ug05spreadsheet.html#ug05subset_transpose (http://www.hdfgroup.org/products/java/hdfview/UsersGuide/ug05spreadsheet.html#ug05subset_transpose)

My point is that logarithmic seems to be an alien concept to meep and it's support software.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 09:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415368#msg1415368">Quote from: aero on 08/11/2015 08:58 PM</a>
....

bluered (opaque blue to transparent white to opaque red). I have several color maps available, this is just the first try. I personally don't like it very much.

This is much better.

I would definitely use this from now on.

This way we can tell what is high amplitude and what is low amplitude.  The previous way....just say no good

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 09:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415372#msg1415372">Quote from: aero on 08/11/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415365#msg1415365">Quote from: X_RaY on 08/11/2015 08:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.
Today (morning) someone pointed out that it may be helpful to use a logarithmic scale, did you try that in the actual case? (one try to compare with the mag. scale?)
Other color map for the mag. scale like you sad could be also helpful i think.

BTW: great work, thanks for spend your time!
I saw that and frankly it gave me a nice chuckle. Two points on a log scale?

See: http://ab-initio.mit.edu/h5utils/h5topng-man.html (http://ab-initio.mit.edu/h5utils/h5topng-man.html) Look really, really closely for the log scale output, then tell me what you find.
Or maybe it would be more fruitful to look here: http://www.hdfgroup.org/products/java/hdfview/UsersGuide/ug05spreadsheet.html#ug05subset_transpose (http://www.hdfgroup.org/products/java/hdfview/UsersGuide/ug05spreadsheet.html#ug05subset_transpose)

My point is that logarithmic seems to be an alien concept to meep and it's support software.
For very good reasons: IMHO a logarithmic scale is the complete opposite of what one wants to do to display mode shapes for these purposes: it will increase the number of contours in the low range and it will decrease them in the high range.

Quote
A logarithmic scale is a nonlinear scale used when there is a large range of quantities. Common uses include the earthquake strength, sound loudness, light intensity, and pH of solutions.

It is based on orders of magnitude, rather than a standard linear scale, so each mark on the scale is the previous mark multiplied by a value.

It will distort all the shapes.  Logarithmic scales are suitable when you have an exponential increasing behavior.  Not suitable for the fields.

May be suitable to plot attenuation, not for discriminating mode shapes from the electromagnetic fields.

Suitable for earthquake strength, sound loudness

(499px-Logarithmic_Scales.svg.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 09:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415376#msg1415376">Quote from: Rodal on 08/11/2015 09:09 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415372#msg1415372">Quote from: aero on 08/11/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415365#msg1415365">Quote from: X_RaY on 08/11/2015 08:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.
Today (morning) someone pointed out that it may be helpful to use a logarithmic scale, did you try that in the actual case? (one try to compare with the mag. scale?)
Other color map for the mag. scale like you sad could be also helpful i think.

BTW: great work, thanks for spend your time!
I saw that and frankly it gave me a nice chuckle. Two points on a log scale?

See: http://ab-initio.mit.edu/h5utils/h5topng-man.html (http://ab-initio.mit.edu/h5utils/h5topng-man.html) Look really, really closely for the log scale output, then tell me what you find.
Or maybe it would be more fruitful to look here: http://www.hdfgroup.org/products/java/hdfview/UsersGuide/ug05spreadsheet.html#ug05subset_transpose (http://www.hdfgroup.org/products/java/hdfview/UsersGuide/ug05spreadsheet.html#ug05subset_transpose)

My point is that logarithmic seems to be an alien concept to meep and it's support software.
For very good reasons: a logarithmic scale is the opposite of what one wants to do to display mode shapes for these purposes: it will increase the number of contours in the low range and it will decreased them in the high range.

Quote
A logarithmic scale is a nonlinear scale used when there is a large range of quantities. Common uses include the earthquake strength, sound loudness, light intensity, and pH of solutions.

It is based on orders of magnitude, rather than a standard linear scale, so each mark on the scale is the previous mark multiplied by a value.

It will distort all the shapes.  Logarithmic scales are suitable when you have an exponential increasing behavior.  Not suitable for the fields.
May be suitable to plot attenuation, not for the fields
OK i can follow your explanation (high vs. low field strength), but i am not sure in view of the resulting pictures. It would be soften the edges we look since the rescaling.
You are the expert here, if you think i isn't helpful then forget it, no problem with that.
And yes it's much better with the new color map!!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 09:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415379#msg1415379">Quote from: X_RaY on 08/11/2015 09:18 PM</a>
...
OK i can follow your explanation (high vs. low field strength), but i am not sure in view of the resulting pictures. It would be soften the edges we look since the rescaling.
You are the expert here, if you think i isn't helpful then forget it, no problem with that.
And yes it's much better with the new color map!!
Well it is just my opinion of course. 
Let's clarify it with an example:  a logarithmic scale is eminently suited to rank earthquakes because each level changes by an order of magnitude.  The difference between an earthquake with a level of 9 from a level of 8 is much greater than the difference between an earthquake between a level of 5 and a level of 4.
Ditto for sound.

Both for sound and earthquakes it makes sense to have a scale that has more levels at low magnitude and less levels at high magnitude.

Now, for the electromagnetic fields, we do not have a scale of electromagnetism where we want to minimize the number of levels at high magnitude and maximize the number of levels at low magnitude.

A linear scale for the mode shapes in EM Drive cavities is fine because we don't have singularities.

A logarithmic scale would make sense for this kind of shape: see the attachment for attenuation where the attenuation goes to Infinity at each end, the plot is clipped at the ends because a linear scale cannot show the singularities at each end.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/11/2015 09:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415383#msg1415383">Quote from: Rodal on 08/11/2015 09:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415379#msg1415379">Quote from: X_RaY on 08/11/2015 09:18 PM</a>
...
OK i can follow your explanation (high vs. low field strength), but i am not sure in view of the resulting pictures. It would be soften the edges we look since the rescaling.
You are the expert here, if you think i isn't helpful then forget it, no problem with that.
And yes it's much better with the new color map!!
Well it is just my opinion of course. 
Let's clarify it with an example:  a logarithmic scale is eminently suited to rank earthquakes because each level changes by an order of magnitude.  The difference between an earthquake with a level of 9 from a level of 8 is much greater than the difference between an earthquake between a level of 5 and a level of 4.
Ditto for sound.

Both for sound and earthquakes it makes sense to have a scale that has more levels at low magnitude and less levels at high magnitude.

Now, for the electromagnetic fields, we do not have a scale of electromagnetism where we want to minimize the number of levels at high magnitude and maximize the number of levels at low magnitude.

A linear scale for the mode shapes in EM Drive cavities is fine because we don't have singularities.

A logarithmic scale would make sense for this kind of shape: see the attachment for attenuation where the attenuation goes to Infinity at each end, the plot is clipped at the ends because a linear scale cannot show the singularities at each end.
Yes you should be right, its a little bi t late and i am tired today.
I just take a look of a random sonnetEM plot  with both scalings... have to agree.
Wish a good night (later for you).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/11/2015 10:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415342#msg1415342">Quote from: Mulletron on 08/11/2015 07:15 PM</a>
Ok since the photons inside the cavity are traveling in a medium at a group velocity <c, we can technically define a frame where the photon is at rest relative to the cavity walls. I can't justify a reason to not treat them as massive particles in calculations.

This is a special case since we're not dealing with photons in vacuum. Does this sound controversial to anyone? That means switching to relativistic momentum.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html

This ref was shared by someone else recently and I think it is significant.

http://arxiv.org/abs/0708.3519

I have found this paper useful and the mathematics makes sense. The relativistic treatment of photons in a waveguide gives them a rest mass, that is proportional to the cut-off frequency of the waveguide.

I've used this in a tapered cylinder waveguide approximation to derive the thrust equation. I've just been too busy to work on my paper for the past couple of weeks.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 08/11/2015 10:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415269#msg1415269">Quote from: SeeShells on 08/11/2015 02:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415250#msg1415250">Quote from: TheTraveller on 08/11/2015 02:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415249#msg1415249">Quote from: X_RaY on 08/11/2015 02:11 PM</a>
My limited experience with the comsol EM module is it works fine!
Without calculations it is difficult(not possible) to say a specific peak in the S-parameter plot is the target resonance.

Sure understand that. But if you do a scan on a cavity and the predicted resonance is not there, then what?

As far as I know, there were no scans to back up all the mode and freq calculations that EW did.
I have a simple VNA I plan to use to find resonance frequencies and it's simply a verification to the calculations.
...
Even NASA should have used VNAs in air and vacuum just to check and I'm not sure they did. 
...

I'd like to propose a logical progression to the VNA analysischaracterize each experimental frustum at multiple temperatures

@deltaMass recently proposed that thermal data could be used as an approximation to how well tuned the frustum was to the source RF feed.  To continue the line of thought, if one could characterize a frustum at discrete temperatures using a VNA , then one could theoretically build a control loop using frustum temperature that varied frequency and/or impedance controls without having to perform real-time VSWR or sample port analysis.

Effectively I'm proposing that a lookup table could be constructed that indicates the optimal experimental control settings for each temperature point.  As the frustum heats up, the optimal experimental control settings can be obtained from the table.  As an implementation detail, one could use curve-fitting to build an equation or use simplistic "if-then-else" to drive the control loop outputs.

While the temperature is likely to be the dominant frustum parameter than impact bandpass characteristics and impedance, other parameters may also be important to in order to implement a control loop that yields repeatable results (i.e. frustum orientation, humidity, etc).

EDIT: On further thought, one might need multiple temperature inputs from different areas on the frustum geometry.  The back-of-napkin reasoning being that temperature differences at certain key locations may have a more pronounced effect on bandpass characteristics and impedance than a single "average" frustum temperature.  I'd guess that the temperature of the "big end" and "small end" are the two dominant parameters.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/11/2015 10:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415235#msg1415235">Quote from: TheTraveller on 08/11/2015 01:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415230#msg1415230">Quote from: Rodal on 08/11/2015 01:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415229#msg1415229">Quote from: deltaMass on 08/11/2015 01:25 PM</a>
I'm still confused. Are we looking at a single impulsive event, or a steady-state force?
The unraveling of the EM Drive "force measurement" this is what is great about replications.
The South African experiment does not show a constant steady-state force.

His fulcrum is undamped and will oscillate for some time before settling at the final value. You know that so why the comment?
Your Quote link to Rodal's comment (about "unraveling") does not work. Can you please provide a working link?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/11/2015 10:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).
Same as mine, 3 blades, 2 balance points.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/11/2015 11:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415404#msg1415404">Quote from: rfmwguy on 08/11/2015 10:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).
Same as mine, 3 blades, 2 balance points.
(charlescalebcolton203963.jpg)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/11/2015 11:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415351#msg1415351">Quote from: deltaMass on 08/11/2015 07:42 PM</a>
How about my other two questions - the power? and why not just an impulse?

An impulse would give an undamped mass-spring* harmonic oscillator an initial velocity to the mass but would not change the equilibrium point : the oscillations would have a mean position around the same equilibrium (before excitation). This is not what we see, even if the time axis lacks of resolution it looks like the response to a step, the mean after excitation is above the pre-excitation position. Too bad the record is too short to see what happens after power-off (why ?) : the undamped oscillator should continue to oscillate, more or less depending on phase at power off, but back around the initial equilibrium point, at least if there is a steep step down back to 0 force at power-off (which somehow often proves elusive with the emdrive experiments).

* in this case the "springiness" is actually a centre of mass below axis (by what amount ?) restoring torque, but this is the same dynamic harmonic oscillator for small linearisable displacements.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 11:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415342#msg1415342">Quote from: Mulletron on 08/11/2015 07:15 PM</a>
Ok since the photons inside the cavity are traveling in a medium at a group velocity <c, we can technically define a frame where the photon is at rest relative to the cavity walls. I can't justify a reason to not treat them as massive particles in calculations.

This is a special case since we're not dealing with photons in vacuum. Does this sound controversial to anyone? That means switching to relativistic momentum.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html

This ref was shared by someone else recently and I think it is significant.

http://arxiv.org/abs/0708.3519

What do you think happens at the height of a mode switch, right at the phase change peak. Time freezes.

Kidding aside, I want to read those papers, but later tonight. Thanks.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 11:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415408#msg1415408">Quote from: Rodal on 08/11/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415404#msg1415404">Quote from: rfmwguy on 08/11/2015 10:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).
Same as mine, 3 blades, 2 balance points.
(charlescalebcolton203963.jpg)
Two balance points for me.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/11/2015 11:34 PM
NSF-1701 Update 8/11/15. Assembly of frustum complete. Final weigh-in 2.383 kg. (grill) Thermometer installed, thanks to an idea from a pal here on NSF. Electrodes (solid copper wire) and terminal strip attached. Frustum is pictured upside down, as test will have small end closest to floor.

Final assembly on microwave (oven) controller just about done. Terminal strip on back and all wired up. Outside case reinstalled, fan and turntable motor disabled. All that's left is to attach copper wire and galinstan copper cups.

Just about at the end of the build phase!!!!!!!!!!!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/11/2015 11:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415358#msg1415358">Quote from: aero on 08/11/2015 08:04 PM</a>
That looks very promising.
No, the -t is what it is, the -x -y and -z are parameters, (one set per png file). But it looks like the shell file will need to undergo major changes. I've attached my shell file (change the extension to .sh). It works for what I have been doing but I am forced by h5topng to copy the .png files into the sub-folders from the -out folder. The new desire to set min/max for each value of t, x, y, z will force us to discard this approach and adopt a naming convention something like I use for the csv files. That shell file is also attached (changed extension) but h5totxt handles the sub-directory correctly so no file moving is needed.

As for running it in bash? Not necessary until the h5topng commands are fully formulated and written to a shell file. You can do all of that in Python if that is your language of choice. Then run that shell file in bash.

You will likely need to create a set of h5 files to run your tests against. Don't go to to much work until you do that because I'm not sure that the single case of data that I generated and posted is representative of what h5topng outputs when multiple files are generated. It's sure not what the attached shell file logs, but then, the attached is probably not representative of the ultimate design, either.

and see the manual, it's short:
http://ab-initio.mit.edu/h5utils/h5topng-man.html (http://ab-initio.mit.edu/h5utils/h5topng-man.html)

Please find attached a shell script generator file (rename from .txt to .py).  Usage:

python generate_shell.py --colormap dkbluered --z-big-end 15 --z-small-end 214 --out-dir ./output_dir --time 0:13

For now, the "-m" minimum, "-M" maximum, and "2-d-loop64-" prefix are hard coded.  You may change these manually on lines 42 and 53-57.  I have not completely coded different min/max values for the ex, ey, ez, hx, hy, hz directions, for now the e/h min/max are the same (e.g. ex min/max is the same as hx min/max).  The input files are assumed to be in out-dir and have the format of dir.h5 where dir is one of ex, ey, ez, hx, hy, hz.

The output is also attached.  Since I am on windows, the file separator is "\", however in unix it should switch to "/" automagically.

This may be useful to you for generating shell scripts using custom min/max values pending the creation of a script to extract the min/max from log files.  If you can post or PM me an actual log file, I can see about creating a new parser that can automate the whole process.  Also, maybe the "h5ls" command can extract the min/max values without having to generate a set of "throwaway" png files?

EDIT: I threw in the h5totxt for free, took about 30 sec once I had the h5topng coded.  Feel free to remove that part.  Also, the output.txt was generated using a slightly different command line than the example from above. :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/11/2015 11:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415420#msg1415420">Quote from: rfmwguy on 08/11/2015 11:34 PM</a>
NSF-1701 Update 8/11/15. Assembly of frustum complete. Final weigh-in 2.383 kg. (grill) Thermometer installed, thanks to an idea from a pal here on NSF. Electrodes (solid copper wire) and terminal strip attached. Frustum is pictured upside down, as test will have small end closest to floor.

Final assembly on microwave (oven) controller just about done. Terminal strip on back and all wired up. Outside case reinstalled, fan and turntable motor disabled. All that's left is to attach copper wire and galinstan copper cups.

Just about at the end of the build phase!!!!!!!!!!!
That is simply beautiful. Nice looking build!

So you got to work on your build I got to smear some tar a roof that was leaking. Something isn't right here.... hmmmm

Very nice.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/11/2015 11:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415424#msg1415424">Quote from: SeeShells on 08/11/2015 11:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415420#msg1415420">Quote from: rfmwguy on 08/11/2015 11:34 PM</a>
NSF-1701 Update 8/11/15. Assembly of frustum complete. Final weigh-in 2.383 kg. (grill) Thermometer installed, thanks to an idea from a pal here on NSF. Electrodes (solid copper wire) and terminal strip attached. Frustum is pictured upside down, as test will have small end closest to floor.

Final assembly on microwave (oven) controller just about done. Terminal strip on back and all wired up. Outside case reinstalled, fan and turntable motor disabled. All that's left is to attach copper wire and galinstan copper cups.

Just about at the end of the build phase!!!!!!!!!!!
That is simply beautiful. Nice looking build!

So you got to work on your build I got to smear some tar a roof that was leaking. Something isn't right here.... hmmmm

Very nice.

Shell
Thanks shell. Get that roof fixed, we can't have leaks at our global test facility ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/12/2015 12:17 AM
@Imbfan-

Making good progress. One simple thing

         Direction('-0x0', 'x', .456, .567),
         Direction('-0y0', 'y', .678, .789),


should be
         Direction('-0 -x 0', 'x', .456, .567),
         Direction('-0 -y 0', 'y', .678, .789),


The -0 is a switch telling h5totxt to use the center of the lattice as the origin, the -x is a switch telling to cut the x axis, that is, look at the y,z plane, and of course the 0 says cut along the x=0 value. Similar for y. And h5totxt and h5topng requires a space to separate switches/values.

I'll look in more detail soon but that was all I saw on first read.

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/12/2015 12:45 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415434#msg1415434">Quote from: aero on 08/12/2015 12:17 AM</a>
@Imbfan-

Making good progress. One simple thing

         Direction('-0x0', 'x', .456, .567),
         Direction('-0y0', 'y', .678, .789),


should be
         Direction('-0 -x 0', 'x', .456, .567),
         Direction('-0 -y 0', 'y', .678, .789),


The -0 is a switch telling h5totxt to use the center of the lattice as the origin, the -x is a switch telling to cut the x axis, that is, look at the y,z plane, and of course the 0 says cut along the x=0 value. Similar for y. And h5totxt and h5topng requires a space to separate switches/values.

I'll look in more detail soon but that was all I saw on first read.

aero

From the manual you linked earlier:

Quote
-0
Shift the origin of the x/y/z slice coordinates to the dataset center, so that e.g. -0 -x 0 (or more compactly -0x0) returns the central x plane of the dataset instead of the edge x plane. (-t coordinates are not affected.)

I could not test, but it's no problem to switch it if it doesn't work.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 12:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415395#msg1415395">Quote from: jmossman on 08/11/2015 10:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415269#msg1415269">Quote from: SeeShells on 08/11/2015 02:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415250#msg1415250">Quote from: TheTraveller on 08/11/2015 02:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415249#msg1415249">Quote from: X_RaY on 08/11/2015 02:11 PM</a>
My limited experience with the comsol EM module is it works fine!
Without calculations it is difficult(not possible) to say a specific peak in the S-parameter plot is the target resonance.

Sure understand that. But if you do a scan on a cavity and the predicted resonance is not there, then what?

As far as I know, there were no scans to back up all the mode and freq calculations that EW did.
I have a simple VNA I plan to use to find resonance frequencies and it's simply a verification to the calculations.
...
Even NASA should have used VNAs in air and vacuum just to check and I'm not sure they did. 
...

I'd like to propose a logical progression to the VNA analysischaracterize each experimental frustum at multiple temperatures

@deltaMass recently proposed that thermal data could be used as an approximation to how well tuned the frustum was to the source RF feed.  To continue the line of thought, if one could characterize a frustum at discrete temperatures using a VNA , then one could theoretically build a control loop using frustum temperature that varied frequency and/or impedance controls without having to perform real-time VSWR or sample port analysis.

Effectively I'm proposing that a lookup table could be constructed that indicates the optimal experimental control settings for each temperature point.  As the frustum heats up, the optimal experimental control settings can be obtained from the table.  As an implementation detail, one could use curve-fitting to build an equation or use simplistic "if-then-else" to drive the control loop outputs.

While the temperature is likely to be the dominant frustum parameter than impact bandpass characteristics and impedance, other parameters may also be important to in order to implement a control loop that yields repeatable results (i.e. frustum orientation, humidity, etc).

EDIT: On further thought, one might need multiple temperature inputs from different areas on the frustum geometry.  The back-of-napkin reasoning being that temperature differences at certain key locations may have a more pronounced effect on bandpass characteristics and impedance than a single "average" frustum temperature.  I'd guess that the temperature of the "big end" and "small end" are the two dominant parameters.

That's a good idea.

Here is how I see it when using copper endplates and copper side walls. Remember, movement the thickness of a piece of paper can trash your Q and resonance.

Upon power you will begin to deform the copper endplates and adjusting the incoming frequency to try to correct will not correct the heat in the mode shapes that is deforming the copper and mode.

The excess heat will migrate through conduction and thermal convection to the side walls where due to the thermal expansion the cavity length will slowly increase pushing you out of tune.

The ideal way would be to keep the endplates from deforming in the first place. By using ceramic plates.  I'm going to have mine electroplated, with gold (very thin). Gold is a great heat conductor but what is good about this setup the plate will not deform under mode hotspots like copper causing mode and cavity degradation.

There is little i can do on the sidewalls thermal expansion but move the small end plate via flat transducers that control positioning by feed back and that would be from a probe in the frustum. I have a coarse lead screw adjustment for the small plate and flat transducers to fine control the Z position as the sidewalls expand.

oops brain spasm!
Thinking out loud here... If I muck it up just shout "danger, danger engineer thinking, please step back"!

To do it right I should couple the small endplate externally to the large with ceramic rods,  avoiding the issue of the cavity walls heating and changing length.  Then I'll free float the plate in the small end, therefor the expanding side walls will just slide on by the plate and not change the distance between the plates, thereby keeping Q and mode. I grok this.

This idea is  a brain spasm in progress, but dang it sounds good. (It would look a little like rfmwguy's frustum build with the external rods between the plates, but free floating one plate). I bet I could do it without any major looped feedback just by building a solid thermal compensating cavity. but ...

Let me recap.

That way I've stabilized the endplates from thermal hot spot mode expansion effects and compensated the cavity growth down the Y axis that changes tune. Maybe I'll need a little snub to control and fine tune the resonance in the end of the cavity driven by a transducer, and that would work easier than pushing a piece of ceramic around.

I've diner waiting, will be back.

Shell


PS: You know I may change my second build, heck I may build it first.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 12:56 AM
We continue our calculations of the gamma function γ as a measure of exponential geometrical attenuation:

Eθ = A e - γ r

where the gamma function γ(r) (which cannot be expressed in terms of any known function appearing in any textbook), has to be obtained as a numerical solution to the differential equation

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

for what we think is most likely the Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θ   = 15.44 °

We show below:
 
1)  γ(r) vs. r for TE011 to max attenuation of 5
2)  γ(r) vs. r for TE011 to max attenuation of 25
3)  Eθ/A vs. r for TE011


Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and smaller distance to the vertex than the previously calculated for 6 ° and larger distance to the vertex
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 01:03 AM
We continue by showing γ for the Yang cavity at 15 ° to the previously calculated for 6 ° side by side.

1) The 6 ° Yang/Shell geometry:

bigDiameter = 0.201(*meter*);
smallDiameter = 0.1492(*meter*);
axialLength = 0.24(*meter*);

r1 = 0.693281 (*meter*); (*spherical small radius *)
r2 = 0.933978  (*meter*); (*spherical large radius *)
θw = 6.15933  ° (*degrees*); (*half-cone angle*)

2) The 15 ° Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θw = 15.44 ° (*degrees*); (*half-cone angle*)

 the geometry we consider is as shown in this image: 

(CavityShape.gif)

We show below:
 
1)  γ(r) vs. r for TE011 15 ° geometry
2)  γ(r) vs. r for TE011 6 ° geometry


Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and closer to the vertex than the previously calculated for 6 ° and farther from the vertex .  When the attenuation gradient is correctly calculated, the attenuation is clearly greater for higher angles and closer to the vertex.

__________________________

These are calculations of the gamma function γ as a measure of exponential geometrical attenuation:

Eθ = A e - γ r

where the gamma function γ(r) (which cannot be expressed in terms of any known function appearing in any textbook), has to be obtained as a numerical solution to the differential equation

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/12/2015 01:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415440#msg1415440">Quote from: lmbfan on 08/12/2015 12:45 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415434#msg1415434">Quote from: aero on 08/12/2015 12:17 AM</a>
@Imbfan-

Making good progress. One simple thing

         Direction('-0x0', 'x', .456, .567),
         Direction('-0y0', 'y', .678, .789),


should be
         Direction('-0 -x 0', 'x', .456, .567),
         Direction('-0 -y 0', 'y', .678, .789),


The -0 is a switch telling h5totxt to use the center of the lattice as the origin, the -x is a switch telling to cut the x axis, that is, look at the y,z plane, and of course the 0 says cut along the x=0 value. Similar for y. And h5totxt and h5topng requires a space to separate switches/values.

I'll look in more detail soon but that was all I saw on first read.

aero

From the manual you linked earlier:

Quote
-0
Shift the origin of the x/y/z slice coordinates to the dataset center, so that e.g. -0 -x 0 (or more compactly -0x0) returns the central x plane of the dataset instead of the edge x plane. (-t coordinates are not affected.)

I could not test, but it's no problem to switch it if it doesn't work.
I remember that now that you mention it. So it likely works as you have it.

I did look at the h5ls statement. I don't think it works for what we want, but it may.  There is no question that a Scilab program could be written to do what we need with the .h5 files, but I'm not going to even think about doing it. It looks to me like a life's work to decipher that language but it looks like it does everything and probably in several ways. Here.

https://help.scilab.org/doc/5.5.2/en_US/index.html (https://help.scilab.org/doc/5.5.2/en_US/index.html)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/12/2015 01:16 AM

Because nobody seems to have posted it (yet)...

...some details on the size of the new Hackaday Rig  (directly from the builders post) :

Quote

Height without the cylindrical endpart: 21.87mm

Height of cylindrical endpart: 5mm

Diameter small end: 16.12mm

Diameter big end: 29.64mm

Frequency is tuneable within 23 to 25 GHz (maybe more, but then the generator works out of spec)

The small end wall will be movable within the cylindrical endpart by a servo for automatic testing.

The endplates are flat - but a sphrical mod is also possible, because the cavity ends are open so we can flange different endplates to it.

Many thanx for your analysis, it´s really amazing that you´re doing that for us.


Do you also need the antenna position/antenna length, or does it not matter?

The current board uses a 3/4 lambda of 24.125GHz

The antenna hole is 5.55mm below the cylindrical endpart.

If this is wrong, we can make another drill. Unfortunately I could not find much information about the antenna position in EMdrives, just the standard 1/4lambda distance from the wall for usual waveguides.

May I suggest somebody add this info to the wiki very shortly?

A couple observations:

First, this device is tiny.  I think I might have junked copper fittings of comparable dimensions out in the garage. Makes a shot glass look huge by comparison.

Second, note his uncertainty about antenna placement - something we have also been wrestling with. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 01:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415453#msg1415453">Quote from: ThinkerX on 08/12/2015 01:16 AM</a>
...May I suggest somebody add this info to the wiki very shortly?...

Thanks very much for posting the information.
I agree that it should be posted once they get results, but can we wait to put it in the wiki until they have reported a measurement?

Presently only data for EM Drives that have been tested are included in the EM Drive wiki

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/12/2015 02:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415420#msg1415420">Quote from: rfmwguy on 08/11/2015 11:34 PM</a>
NSF-1701 Update 8/11/15. Assembly of frustum complete. Final weigh-in 2.383 kg. (grill) Thermometer installed, thanks to an idea from a pal here on NSF. Electrodes (solid copper wire) and terminal strip attached. Frustum is pictured upside down, as test will have small end closest to floor.

Final assembly on microwave (oven) controller just about done. Terminal strip on back and all wired up. Outside case reinstalled, fan and turntable motor disabled. All that's left is to attach copper wire and galinstan copper cups.

Just about at the end of the build phase!!!!!!!!!!!

I suggest you twist the wires tightly and put shielding around all the voltage terminals, wires, etc. up to the contact cups. So that there are no spurious Lorentz forces acting on it.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/12/2015 02:21 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415449#msg1415449">Quote from: Rodal on 08/12/2015 01:03 AM</a>
We continue by showing γ for the Yang cavity at 15 ° to the previously calculated for 6 ° side by side.

1) The 6 ° Yang/Shell geometry:

bigDiameter = 0.201(*meter*);
smallDiameter = 0.1492(*meter*);
axialLength = 0.24(*meter*);

r1 = 0.693281 (*meter*); (*spherical small radius *)
r2 = 0.933978  (*meter*); (*spherical large radius *)
θw = 6.15933  ° (*degrees*); (*half-cone angle*)

2) The 15 ° Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θw = 15.44 ° (*degrees*); (*half-cone angle*)

 the geometry we consider is as shown in this image: 

(CavityShape.gif)

We show below:
 
1)  γ(r) vs. r for TE011 15 ° geometry
2)  γ(r) vs. r for TE011 6 ° geometry


Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and closer to the vertex than the previously calculated for 6 ° and farther from the vertex .  When the attenuation gradient is correctly calculated, the attenuation is clearly greater for higher angles and closer to the vertex.

__________________________

These are calculations of the gamma function γ as a measure of exponential geometrical attenuation:

Eθ = A e - γ r

where the gamma function γ(r) (which cannot be expressed in terms of any known function appearing in any textbook), has to be obtained as a numerical solution to the differential equation

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

By that conclusion, we can practically guarantee that a smaller cone angle will have a higher Q, because the loss due to attenuation is much smaller.

FYI: What you're doing makes a lot more sense to me than what Z&F were showing. No wonder I was having such a difficult time interpreting their results.

Now, my question is, was Yang right when she said that the more cylindrical frustum with higher Q had the greatest thrust? Shell may do better than we expect with her 6-deg. frustum, but not because of what we thought we knew 2 months ago.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/12/2015 03:37 AM
@Imbfan-

Here are your files back to you. You will note that I tinkered with them but not for posterity.

- I put the run command at the top of the executable files as a comment - Just so I won't forget what it is.
- I added the "2>&1 |  tee nemonic-name.log" bash switch to the run commands to save the std output to a log file.
- I commented the csv file print output statements, don't want or need csv's to find the min/max values >>> unless the -v switch on h5totxt also gives the min/max values, then because it's faster we will use it instead.
- I edited in the -v (verbose) option to the .py run log file and changed the extension to .sh - also changed the name of the output directory to "garbage" and removed the color map trying to speed things up. Didn't help much.
- I ran the resulting shell file and obtained a verbose.log file >>> this is the one that has the real min/max values...

Unfortunately I wasn't very careful with saving the files so in particular the "generate_shell.log" file may be partly or mostly edited, not the actual output from your Python program.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/12/2015 05:35 AM

Looking for litterature on the subject of forces and momentum in electromagnetic systems, I have found this article dated from october 2002 : "On an Additional Magnetic Force Present in a System of Coaxial Solenoids", http://pdf.lu/72oA (http://pdf.lu/72oA). The conclusion of this paper is the following :
Quote
More generally, experiments to validate or disconfirm, in suitable geometries, the various terms of our proposed generalized equation of motion (7) would evidently be desirable. The Lorentz force is the only one of those terms currently known beyond doubt to be physically valid. For a century too much has been left to accepted electromagnetic theory and not enough to empirical inquiry.

Phenomenology and empirical investigation seem well today be the future of electromagnetism !

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/12/2015 06:41 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415486#msg1415486">Quote from: Mezzenile on 08/12/2015 05:35 AM</a>
Looking for litterature on the subject of forces and momentum in electromagnetic systems, I have found this article dated from october 2002 : "On an Additional Magnetic Force Present in a System of Coaxial Solenoids", http://pdf.lu/72oA (http://pdf.lu/72oA). The conclusion of this paper is the following :
Quote
More generally, experiments to validate or disconfirm, in suitable geometries, the various terms of our proposed generalized equation of motion (7) would evidently be desirable. The Lorentz force is the only one of those terms currently known beyond doubt to be physically valid. For a century too much has been left to accepted electromagnetic theory and not enough to empirical inquiry.

Phenomenology and empirical investigation seem well today be the future of electromagnetism !
That was written 13 years ago. Can you hear the crickets?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/12/2015 07:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415420#msg1415420">Quote from: rfmwguy on 08/11/2015 11:34 PM</a>
NSF-1701 Update 8/11/15. Assembly of frustum complete. Final weigh-in 2.383 kg. (grill) Thermometer installed, thanks to an idea from a pal here on NSF. Electrodes (solid copper wire) and terminal strip attached. Frustum is pictured upside down, as test will have small end closest to floor.

Final assembly on microwave (oven) controller just about done. Terminal strip on back and all wired up. Outside case reinstalled, fan and turntable motor disabled. All that's left is to attach copper wire and galinstan copper cups.

Just about at the end of the build phase!!!!!!!!!!!
Now the NSF-1701 looks like a very important part of the NCC-1701  ;D  ;)
Good luck for your coming tests :)

pictures:  rfmwguy and  http://www.cygnus-x1.net/links/lcars/ksy-enterprise.php

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/12/2015 07:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415412#msg1415412">Quote from: SeeShells on 08/11/2015 11:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415408#msg1415408">Quote from: Rodal on 08/11/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415404#msg1415404">Quote from: rfmwguy on 08/11/2015 10:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).
Same as mine, 3 blades, 2 balance points.
(charlescalebcolton203963.jpg)
Two balance points for me.
Shell your bearing is able to produce a lot of friction..  ???
What do you think about commercial bearings for your carbon construction? metal, plastic or ceramic

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/12/2015 08:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415449#msg1415449">Quote from: Rodal on 08/12/2015 01:03 AM</a>
.......

Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and closer to the vertex than the previously calculated for 6 ° and farther from the vertex .  When the attenuation gradient is correctly calculated, the attenuation is clearly greater for higher angles and closer to the vertex.

........
Dr. Rodal,
For a while i was wondering what you were doing as I did not understand the purpose of the graphs, but your last explanation made it clear for me. Thanks for that....

As you have the opportunity now to calculate the attenuation gradient for a half cone angle, do you think it is possible to investigate if there is an optimal angle?
fe, calculate the gamma for each 5° incremental to see how the attenuation evolves through the different angles? Does attenuation continue to increase with the increasing angle or is there an optimum angle?

 Information like this would be crucial for redesigning frustums to achieve max attenuation and would consequently assist in answering the question to what gives the most net force result in a frustum : a high Q, or a high attenuation or maybe, as Todd previously suggested, Q and attenuation needs to balance each other?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: andygood on 08/12/2015 09:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415443#msg1415443">Quote from: SeeShells on 08/12/2015 12:52 AM</a>
To do it right I should couple the small endplate externally to the large with ceramic rods,  avoiding the issue of the cavity walls heating and changing length.  Then I'll free float the plate in the small end, therefor the expanding side walls will just slide on by the plate and not change the distance between the plates, thereby keeping Q and mode. I grok this...

Great idea! This is what I liked about the Tajmar setup. His small plate appears to be mechanically connected to the large plate via the external adjustment mechanism, isolating it from the frustum... Pity about that 'Great Bloody Hole'TM in the side of it though... With your added ceramic-endplate goodness, you have a recipe for some interesting tests...  8)

Another idea that's been knocking around in my skull for a while would be to fabricate a frustum shaped block out of a high-k ceramic and then plate the whole thing...  ???

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/12/2015 09:41 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415507#msg1415507">Quote from: andygood on 08/12/2015 09:02 AM</a>
... Another idea that's been knocking around in my skull for a while would be to fabricate a frustum shaped block out of a high-k ceramic and then plate the whole thing...  ???
Do we have and orde of magnitude for the Q reduction due to copper oxydation by the oxygen of air ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/12/2015 09:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415497#msg1415497">Quote from: X_RaY on 08/12/2015 07:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415412#msg1415412">Quote from: SeeShells on 08/11/2015 11:15 PM</a>
...
Two balance points for me.
Shell your bearing is able to produce a lot of friction..  ???
What do you think about commercial bearings for your carbon construction? metal, plastic or ceramic

Why not a short hardened steel tubing sheath around the carbon tube where it rests on the knife edge ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/12/2015 11:28 AM
Can't stop thinking about @Notsosureofit's accelerated frame of reference model.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 11:41 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415502#msg1415502">Quote from: Flyby on 08/12/2015 08:26 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415449#msg1415449">Quote from: Rodal on 08/12/2015 01:03 AM</a>
.......

Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and closer to the vertex than the previously calculated for 6 ° and farther from the vertex .  When the attenuation gradient is correctly calculated, the attenuation is clearly greater for higher angles and closer to the vertex.

........
Dr. Rodal,
For a while i was wondering what you were doing as I did not understand the purpose of the graphs, but your last explanation made it clear for me. Thanks for that....

As you have the opportunity now to calculate the attenuation gradient for a half cone angle, do you think it is possible to investigate if there is an optimal angle?
fe, calculate the gamma for each 5° incremental to see how the attenuation evolves through the different angles? Does attenuation continue to increase with the increasing angle or is there an optimum angle?

 Information like this would be crucial for redesigning frustums to achieve max attenuation and would consequently assist in answering the question to what gives the most net force result in a frustum : a high Q, or a high attenuation or maybe, as Todd previously suggested, Q and attenuation needs to balance each other?

Unfortunately, calculating this for just one geometry is very time consuming .  At the moment the best I can do is to compare a few geometries  (so far I have only compared two geometries).  So all I can see at the moment is:

if the hypothesis that an increasing gradient of attenuation towards the vertex is good is true

1) The Yang geometry with 15 degrees and closer to the vertex is better than the Yang geometry with 6 degrees and further from the vertex

2) The lower mode shape TE011 looks better than TE012

Need to look at other geometries and mode shapes.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 11:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415445#msg1415445">Quote from: Rodal on 08/12/2015 12:56 AM</a>
We continue our calculations of the gamma function γ as a measure of exponential geometrical attenuation:

Eθ = A e - γ r

where the gamma function γ(r) (which cannot be expressed in terms of any known function appearing in any textbook), has to be obtained as a numerical solution to the differential equation

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

for what we think is most likely the Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θ   = 15.44 °

We show below:
 
1)  γ(r) vs. r for TE011 to max attenuation of 5
2)  γ(r) vs. r for TE011 to max attenuation of 25
3)  Eθ/A vs. r for TE011


Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and smaller distance to the vertex than the previously calculated for 6 ° and larger distance to the vertex

We continue the above study by showing the results for mode shape TE012

We show below:
 
1)  γ(r) vs. r for TE012 to max attenuation of 5
2)  γ(r) vs. r for TE012 to max attenuation of 25
3)  Eθ/A vs. r for TE012

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 11:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415449#msg1415449">Quote from: Rodal on 08/12/2015 01:03 AM</a>
We continue by showing γ for the Yang cavity at 15 ° to the previously calculated for 6 ° side by side.

1) The 6 ° Yang/Shell geometry:

bigDiameter = 0.201(*meter*);
smallDiameter = 0.1492(*meter*);
axialLength = 0.24(*meter*);

r1 = 0.693281 (*meter*); (*spherical small radius *)
r2 = 0.933978  (*meter*); (*spherical large radius *)
θw = 6.15933  ° (*degrees*); (*half-cone angle*)

2) The 15 ° Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θw = 15.44 ° (*degrees*); (*half-cone angle*)

 the geometry we consider is as shown in this image: 

(CavityShape.gif)

We show below:
 
1)  γ(r) vs. r for TE011 15 ° geometry
2)  γ(r) vs. r for TE011 6 ° geometry


Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and closer to the vertex than the previously calculated for 6 ° and farther from the vertex .  When the attenuation gradient is correctly calculated, the attenuation is clearly greater for higher angles and closer to the vertex.

__________________________

These are calculations of the gamma function γ as a measure of exponential geometrical attenuation:

Eθ = A e - γ r

where the gamma function γ(r) (which cannot be expressed in terms of any known function appearing in any textbook), has to be obtained as a numerical solution to the differential equation

r dγ/dr + γ = - (1/Eθ)*dEθ/dr

We continue the above study by showing the results for TE012 comparing the 6 degree and the 15 degree Yang geometries

We show below:
 
1)  γ(r) vs. r for TE012 15 ° geometry
2)  γ(r) vs. r for TE012 6 ° geometry

Clearly, the geometrical attenuation γ(r) is much greater for the Yang cavity at 15 ° and closer to the vertex than the previously calculated for 6 ° and farther from the vertex .  When the attenuation gradient is correctly calculated, the attenuation is clearly greater for higher angles and closer to the vertex.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 12:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415468#msg1415468">Quote from: WarpTech on 08/12/2015 02:21 AM</a>
...By that conclusion, we can practically guarantee that a smaller cone angle will have a higher Q, because the loss due to attenuation is much smaller.

FYI: What you're doing makes a lot more sense to me than what Z&F were showing. No wonder I was having such a difficult time interpreting their results.

Now, my question is, was Yang right when she said that the more cylindrical frustum with higher Q had the greatest thrust? Shell may do better than we expect with her 6-deg. frustum, but not because of what we thought we knew 2 months ago.
Todd

Actually, calculating the Q factor as

qualityFactor = (2/skinDepth)*(energyVolumeIntegral/energySurfaceIntegral)


results in slightly higher Q for the 15 degree geometry than for the 6 degree geometry:

Mode shape TE012

Q (6 degree geometry)   = 71,173
Q (15 degree geometry) = 73,658

using   resistivity =  1.678*10^(-8)(*copper*);

(For impure copper or other alloys the Q will decrease with the increasing resistivity)

And a calculation for TheTraveller's 30 degree geometry showed a theoretical Q near 100,000

So, calculating

qualityFactor = (2/skinDepth)*(energyVolumeIntegral/energySurfaceIntegral)

although higher angles result in greater attenuation, the Q actually goes up rather than down because less of the energy is exposed to the surface

Everything I have looked at so far consistently points toward higher cone angles and being closer to the vertex as being better, which is in agreement with Shawyer's, McCulloch's and Notsosureofit's formulas.

(As long as there is an electromagnetic field mode shape filling the cavity towards the small base:  extending the cone with a mode that doesn't reach the small base is wasted volume: it results in lower Q)

TE modes have higher Q than TM modes.

___________________

1) The 6 ° Yang/Shell geometry:

bigDiameter = 0.201(*meter*);
smallDiameter = 0.1492(*meter*);
axialLength = 0.24(*meter*);

r1 = 0.693281 (*meter*); (*spherical small radius *)
r2 = 0.933978  (*meter*); (*spherical large radius *)
θw = 6.15933  ° (*degrees*); (*half-cone angle*)

2) The 15 ° Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θw = 15.44 ° (*degrees*); (*half-cone angle*)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 12:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415497#msg1415497">Quote from: X_RaY on 08/12/2015 07:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415412#msg1415412">Quote from: SeeShells on 08/11/2015 11:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415408#msg1415408">Quote from: Rodal on 08/11/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415404#msg1415404">Quote from: rfmwguy on 08/11/2015 10:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).
Same as mine, 3 blades, 2 balance points.
(charlescalebcolton203963.jpg)
Two balance points for me.
Shell your bearing is able to produce a lot of friction..  ???
What do you think about commercial bearings for your carbon construction? metal, plastic or ceramic
It could if I wasn't using a trick here that I needed to mention and I'm really sorry it slipped my mind. The knife edge really isn't a knife edge anymore, it has been rounded off using a belt sander and the tube simply rolls over the rounded surface of the blade that was a sharp edge.

I liked the strength of the blade but I disliked the friction and stresses when using 2 blades one on top of each other or the way the blade could slice into a metal or a carbon fiber tube. In testing I had the blades chip and shatter against each other and glued steel plates end up getting a grove from the blade in just a couple runs up and down with weights on the fulcrum.

A mental calculation thinking about the small radii the tube would roll over changing the length over 1 meter was around 5 microns. It's acceptable.

Added: What do you think xray? Do you think this will work ok? I wanted to try and avoid any bearing for they seem to always have the issued of initial movement from stiction.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/12/2015 12:44 PM
@Dr. Rodal ("And/Or curious others")

Would you be able to produce output using the tool or formula of your choice at your leisure to see how relative humidity might impact results?

If you already know. Please don't waste your time.

I just am curious that I have not seen any mention about RH having any cause or effect or that the impact of RH differences are so small, that they don't need to be considered.

With the large differences in thrust results for tests done in a vacuum compared to testing under normal atmospheric pressure conditions. I've been wondering if RH could be a major contributing cause to those differences.

Note: I just can't help having "flashbacks" to my U.S. Air Force days as a Wideband Communications Equipment 304x0 equipment repair person (http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA201690) in the 1970's who maintained microwave equipment using near these same microwave frequencies.

One of my many maintenance duties was to replace desiccant in every waveguide we used and it was not simply to avoid only rust and/or condensation, in those waveguides.

It has been awhile. But I think one of the reasons why we used desiccant and replaced it so often in all our waveguides had to do with standing waves. I could be remembering this incorrectly. But that's what I recall today. That said. The situation I am referencing was at a site where our microwave transmit power was 10 KW per 60 foot parabolic antenna. Shown below.

(MartinaFrancaItaly.jpg

Thanks

Edited: For photo

Don
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 12:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
@Dr. Rodal ("And/Or curious others")

Would you be able to produce output using the tool or formula of your choice at your leisure to see how relative humidity might impact results?

If you already know. Please don't waste your time.

I just am curious that I have not seen any mention about RH having any cause or effect or that the impact of RH differences are so small, that they don't need to be considered.

With the large differences in thrust results for tests done in a vacuum compared to testing under normal atmospheric pressure conditions. I've been wondering if RH could be a major contributing cause to those differences.

Thanks

Don

Hi, I have not taken the time to consider how to calculate how humidity may affect the results.  I agree that it sounds very interesting for many reasons.  For example, we know how microwave ovens preferentially excite a water molecule and they mostly heat food by heating water, so moist air is most relevant.  I would have to think about how to include that effect in calculations :)

For the time being it would be useful if experimenters would record and report the relative humidity of the environment when they performed their tests.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/12/2015 01:25 PM
EMDrive Rotary Test Table and 5GHz WiFi USB comms

Have gone with a single wireless USB to USB connection between the Laptop and the Raspberry 2B control and monitoring system using a 5GHz WiFi HotSpot generated by my mobile phone. This should eliminate USB to USB comms interference by any 2.45GHz stray Rf that gets out of the Faraday Cage around the EMDrive and the 100W Rf amp. Will be using the high power upper band 5GHz WiFi channels to be sure to get a good connection.

The wireless Raspberry 2B USB to Laptop USB link will enable live, real time data to be displayed on the LapTop and to allow real time control over all EMDrive operational parameters.

Using the 5GHz WiFi HotSpot generated by my mobile phone, means there is no need for the test / demo site to have 5GHz WiFi availability.

Doing this saves me a few modules to write the code for, debug and interface.

The raspberry 2B Control and Monitoring System will collect in real time and log the following data every 10ms or 100 samples per second:

Force generated - calculated
Angular velocity - measured
Angular acceleration - calculated & measured by a 3 axis onboard axis accelerometer
Forward Rf power - measured
Reflected Rf power - measured
VSWR - calculated
Frustum Q - measured
Frustum bandwidth - measured
Frequency - as generated and measured
Rf amp Voltage, Current and Power consumed - measured
Internal frustum pressure - measured
End plate, side wall, ambient and Rf amp temperature - measured
Date and Time to a sub millisecond accuracy - measured
Latitude, Longitude and elevation from mobile phone GPS data - measured.

Rotary table layout as attached.

As always comments most welcome.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 01:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415537#msg1415537">Quote from: Rodal on 08/12/2015 12:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415468#msg1415468">Quote from: WarpTech on 08/12/2015 02:21 AM</a>
...By that conclusion, we can practically guarantee that a smaller cone angle will have a higher Q, because the loss due to attenuation is much smaller.

FYI: What you're doing makes a lot more sense to me than what Z&F were showing. No wonder I was having such a difficult time interpreting their results.

Now, my question is, was Yang right when she said that the more cylindrical frustum with higher Q had the greatest thrust? Shell may do better than we expect with her 6-deg. frustum, but not because of what we thought we knew 2 months ago.
Todd

Actually, calculating the Q factor as

qualityFactor = (2/skinDepth)*(energyVolumeIntegral/energySurfaceIntegral)


results in slightly higher Q for the 15 degree geometry than for the 6 degree geometry:

Mode shape TE012

Q (6 degree geometry)   = 71,173
Q (15 degree geometry) = 73,658

using   resistivity =  1.678*10^(-8)(*copper*);

(For impure copper or other alloys the Q will decrease with the increasing resistivity)

And a calculation for TheTraveller's 30 degree geometry showed a theoretical Q near 100,000

So, calculating

qualityFactor = (2/skinDepth)*(energyVolumeIntegral/energySurfaceIntegral)

although higher angles result in greater attenuation, the Q actually goes up rather than down because less of the energy is exposed to the surface

Everything I have looked at so far consistently points toward higher cone angles and being closer to the vertex as being better, which is agreement with Shawyer's, McCulloch's and Notsosureofit's formulas.

(As long as there is an electromagnetic field mode shape filling the cavity towards the small base:  extending the cone with a mode that doesn't reach the small base is wasted volume: it results in lower Q)

TE modes have higher Q than TM modes.

___________________

1) The 6 ° Yang/Shell geometry:

bigDiameter = 0.201(*meter*);
smallDiameter = 0.1492(*meter*);
axialLength = 0.24(*meter*);

r1 = 0.693281 (*meter*); (*spherical small radius *)
r2 = 0.933978  (*meter*); (*spherical large radius *)
θw = 6.15933  ° (*degrees*); (*half-cone angle*)

2) The 15 ° Yang EM Drive geometry:

bigDiameter = 0.247 (*meter*);
smallDiameter = 0.1144253 (*meter*);
axialLength = 0.24 (*meter*);

r1 = 0.211022 (*meter*);
r2 = 0.455515 (*meter*);
θw = 15.44 ° (*degrees*); (*half-cone angle*)

Some very nice work, over the top for the both of you, hats off to warptech and Dr. Rodal.

Since this build has had input from so many of you and has been a creative mindsink that I've never been involved with or even have seen. I'd like some input on what you think for the second build dimensions.

I'll still be using the octagonal 6 sided shape for several reasons.

Mounting of the waveguides is much easier to the flat walls and making them 180 degrees out from each other and in the same plane.

The ceramic plates are easier to get with flat sides (think of cutting a circle with a circular blade like in a dicing saw).

If I go with ceramics for the side walls later they also are easier to cut.

I'll still use a perforated side wall copper O2 free sheet to downsize the ballooning effects but with smaller holes with wider spacing.

PM me if you would like or throw it out in the forum.

Shell

PS: I think I know what you would like to see Dr. Rodal. ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/12/2015 01:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415554#msg1415554">Quote from: Rodal on 08/12/2015 12:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
@Dr. Rodal ("And/Or curious others")

Would you be able to produce output using the tool or formula of your choice at your leisure to see how relative humidity might impact results?

If you already know. Please don't waste your time.

I just am curious that I have not seen any mention about RH having any cause or effect or that the impact of RH differences are so small, that they don't need to be considered.

With the large differences in thrust results for tests done in a vacuum compared to testing under normal atmospheric pressure conditions. I've been wondering if RH could be a major contributing cause to those differences.

Thanks

Don

Hi, I have not taken the time to consider how to calculate how humidity may affect the results.  I agree that it sounds very interesting for many reasons.  For example, we know how microwave ovens preferentially excite a water molecule and they mostly heat food by heating water, so moist air is most relevant.  I would have to think about how to include that effect in calculations :)

For the time being it would be useful if experimenters would record and report the relative humidity of the environment when they performed their tests.

Another sign of getting older. Sigh.....

I forgot to mention, that we also used both horizontal and vertical polarity with our microwave antennas for diversity. In some cases vertical or horizontal polarities made major differences with different atmospheric conditions.

Antennas which received our microwave signals ("Using tropospheric scatter") were as much as 400 miles away. So there were multiple weather conditions which our microwave transmissions could encounter as they tried to reach our distant ends.

I have no idea if this applies to EM Drives or not.

But I am surprised that there has been little test data to compare when a waveguide is used to inject the microwave signal into the EM Drive if the waveguide was in a horizontal or vertical mounting position on the EM Drive and if the polarity of that waveguide, could have any effect on measured results when using the same sized EM Drive with the opposite polarity to compare horizontal to vertical polarities. Near or about at the same mounting position.

I'm not sure if any of your test tools or formulas allow waveguides to use horizontal or vertical polarities as input data to see if any polarity differences might make the output of same, have different results.

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 02:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415570#msg1415570">Quote from: TheUberOverLord on 08/12/2015 01:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415554#msg1415554">Quote from: Rodal on 08/12/2015 12:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
@Dr. Rodal ("And/Or curious others")

Would you be able to produce output using the tool or formula of your choice at your leisure to see how relative humidity might impact results?

If you already know. Please don't waste your time.

I just am curious that I have not seen any mention about RH having any cause or effect or that the impact of RH differences are so small, that they don't need to be considered.

With the large differences in thrust results for tests done in a vacuum compared to testing under normal atmospheric pressure conditions. I've been wondering if RH could be a major contributing cause to those differences.

Thanks

Don

Hi, I have not taken the time to consider how to calculate how humidity may affect the results.  I agree that it sounds very interesting for many reasons.  For example, we know how microwave ovens preferentially excite a water molecule and they mostly heat food by heating water, so moist air is most relevant.  I would have to think about how to include that effect in calculations :)

For the time being it would be useful if experimenters would record and report the relative humidity of the environment when they performed their tests.

Another sign of getting older. Sigh.....

I forgot to mention, that we also used both horizontal and vertical polarity with our microwave antennas for diversity. In some cases vertical or horizontal polarities made major differences with different atmospheric conditions.

Antennas which received our microwave signals ("Using tropospheric scatter") were as much as 400 miles away. So there were multiple weather conditions which our microwave transmission could encounter to reach our distant ends.

I have no idea if this applies to EM Drives or not.

But I am surprised that there has been little test data to compare when a waveguide is used to inject the microwave signal into the EM Drive if the waveguide was in a horizontal or vertical mounting position on the EM Drive and if the polarity of that waveguide, could have any effect on measured results when using the same sized EM Drive with the opposite polarity to compare horizontal to vertical polarities. Near or about at the same mounting position.

I'm not sure if any of your test tools or formulas allow waveguides to use horizontal or vertical polarities as input data to see if any polarity differences might make the output of same, have different results.

Don
Good points Don, nice post.

Ok... this is from a gal who though she knew something about antennas and I'd like your input because I found out I really don't. I would guess over the last couple months this group has dug into antennas quite deep and I've read more about them than I care to think of. Weird and beautiful stuff.

A couple of things that are on the the forefront that to me have seemed to be of importance.

First off is the radiation patterns and how they must be aligned correctly to excite one or the other, TE or TM mode pattern in the frustum.

Second is the radiation pattern needs to be as uniform as it can, with no funny lobes. A simple snub @ 2.45GHz in a TE insertion point towards the bottom leads to rotational effects of the modes around the cavity. As they build and collapse it kills off the Q of the cavity.
 
Third is the losses associated with an antenna into the cavity. We have calculated only 40-50 watts of effective RF being available to cause a thrust effect in the cavity.

Fourth that low output is why many (Including me) have elected to treat the Frustum like part of a waveguide and directly inject the output of a magnetron down a waveguide into the cavity. rfmwguy coupled his magnetron directly into his cavity, the man is awsum.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/12/2015 02:28 PM
NSF-1701 live test...Galinstan ordered and should be here within a week. Will do the live test either 8/18 or 8/25 depending on the delivery.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/12/2015 02:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415568#msg1415568">Quote from: sghill on 08/12/2015 01:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415554#msg1415554">Quote from: Rodal on 08/12/2015 12:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
@Dr. Rodal ("And/Or curious others")

Would you be able to produce output using the tool or formula of your choice at your leisure to see how relative humidity might impact results?

If you already know. Please don't waste your time.

I just am curious that I have not seen any mention about RH having any cause or effect or that the impact of RH differences are so small, that they don't need to be considered.

With the large differences in thrust results for tests done in a vacuum compared to testing under normal atmospheric pressure conditions. I've been wondering if RH could be a major contributing cause to those differences.

Thanks

Don

Hi, I have not taken the time to consider how to calculate how humidity may affect the results.  I agree that it sounds very interesting for many reasons.  For example, we know how microwave ovens preferentially excite a water molecule and they mostly heat food by heating water, so moist air is most relevant.  I would have to think about how to include that effect in calculations :)

For the time being it would be useful if experimenters would record and report the relative humidity of the environment when they performed their tests.

For a non-sealed EMDrive cavity that's exposed to the air, any humidity in the cavity will heat up and vent out of any openings- including wave-guides and wiring harnesses, but eventually, it'll all be gone, so the longer the magnetron is turned on, the more steam will evaporate and escape.  Any anomalous thrust would tend towards zero over time because of humidity as the device clears out the water vapor in the form of pressurized steam.

For an EMDrive operated in a vacuum, any humidity would get flushed out as the pump reduces the air pressure inside the chamber.

For a "perfectly" sealed EM Drive, the steam would build up pressure inside the EMDrive as energy is added to the system, but no thrust would be measured external to the system.  Until, of course, the balloon pops.

Trusting a vaccum to get rid of water is not quite that simple:

see:  http://cas.web.cern.ch/cas/Spain-2006/PDFs/Dylla-2.pdf

You're looking at hours to eliminate water, even with heat.

They don't characterize copper in the citation above, which would probably make things worse.  Copper is on the list of metals to avoid in high vacuum systems due to outgassing issues.

Also note that outgassing torr has a conversion to gram-force/centimeter2 or newtons/centimeter2

You will get thrust from outgassing based on the surface area.  Not a lot, but some.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/12/2015 02:41 PM
@Imbfan-

I sent a PM to you just now describing the attached. Here is a complete log file to work with.

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TenKen on 08/12/2015 02:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415584#msg1415584">Quote from: rfmwguy on 08/12/2015 02:28 PM</a>
NSF-1701 live test...Galinstan ordered and should be here within a week. Will do the live test either 8/18 or 8/25 depending on the delivery.

I think X_Ray asked this earlier but I didn't see your response: do you have any plans to record your tests, so people who aren't able to watch it live can still watch the video?  (Depending on what streaming program you're using, this may be a built-in function.)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ramachandra on 08/12/2015 03:00 PM
I am a Newbie and a lurker I bow to all of you for your unbounded enthusiasm and hardwork. While I am not a DIYer, I have been following with all the DIY projects. I have a humble suggestion.
I was changing the parameters in the McCalloch Thrust calculation Spreadsheet. (Excellent work!)
By having the same power and changing the geometry and size of the frustum, more than 1 N can be achived, it looks like.
(Changed based on Juan 2 corrected values)
      
                       Updated
Input               Reference Value
Big Diameter   28
Small Diameter   1
Cavity Length   100
Q                 5000
Frequency           2.45
Power          1000
Big Radius          14
Small Radius   0.5
   
mN Force          1608.75
mN Force         1081.08
mN Force         1025.45

This could prove the validity of McCalloch calculations.
Just a humble suggestion.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/12/2015 03:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415581#msg1415581">Quote from: SeeShells on 08/12/2015 02:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415570#msg1415570">Quote from: TheUberOverLord on 08/12/2015 01:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415554#msg1415554">Quote from: Rodal on 08/12/2015 12:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
@Dr. Rodal ("And/Or curious others")

Would you be able to produce output using the tool or formula of your choice at your leisure to see how relative humidity might impact results?

If you already know. Please don't waste your time.

I just am curious that I have not seen any mention about RH having any cause or effect or that the impact of RH differences are so small, that they don't need to be considered.

With the large differences in thrust results for tests done in a vacuum compared to testing under normal atmospheric pressure conditions. I've been wondering if RH could be a major contributing cause to those differences.

Thanks

Don

Hi, I have not taken the time to consider how to calculate how humidity may affect the results.  I agree that it sounds very interesting for many reasons.  For example, we know how microwave ovens preferentially excite a water molecule and they mostly heat food by heating water, so moist air is most relevant.  I would have to think about how to include that effect in calculations :)

For the time being it would be useful if experimenters would record and report the relative humidity of the environment when they performed their tests.

Another sign of getting older. Sigh.....

I forgot to mention, that we also used both horizontal and vertical polarity with our microwave antennas for diversity. In some cases vertical or horizontal polarities made major differences with different atmospheric conditions.

Antennas which received our microwave signals ("Using tropospheric scatter") were as much as 400 miles away. So there were multiple weather conditions which our microwave transmission could encounter to reach our distant ends.

I have no idea if this applies to EM Drives or not.

But I am surprised that there has been little test data to compare when a waveguide is used to inject the microwave signal into the EM Drive if the waveguide was in a horizontal or vertical mounting position on the EM Drive and if the polarity of that waveguide, could have any effect on measured results when using the same sized EM Drive with the opposite polarity to compare horizontal to vertical polarities. Near or about at the same mounting position.

I'm not sure if any of your test tools or formulas allow waveguides to use horizontal or vertical polarities as input data to see if any polarity differences might make the output of same, have different results.

Don
Good points Don, nice post.

Ok... this is from a gal who though she knew something about antennas and I'd like your input because I found out I really don't. I would guess over the last couple months this group has dug into antennas quite deep and I've read more about them than I care to think of. Weird and beautiful stuff.

A couple of things that are on the the forefront that to me have seemed to be of importance.

First off is the radiation patterns and how they must be aligned correctly to excite one or the other, TE or TM mode pattern in the frustum.

Second is the radiation pattern needs to be as uniform as it can, with no funny lobes. A simple snub @ 2.45GHz in a TE insertion point towards the bottom leads to rotational effects of the modes around the cavity. As they build and collapse it kills off the Q of the cavity.
 
Third is the losses associated with an antenna into the cavity. We have calculated only 40-50 watts of effective RF being available to cause a thrust effect in the cavity.

Fourth that low output is why many (Including me) have elected to treat the Frustum like part of a waveguide and directly inject the output of a magnetron down a waveguide into the cavity. rfmwguy coupled his magnetron directly into his cavity, the man is awsum.

Thanks.

First, by no means is my experience even close to yours or others here.

That said. I can't see how when mounting a waveguide to a EM Drive in a horizontal vs. vertical position could not have major effects on how the microwave transmission propagates in a closed Frustum cavity.

After all. It was one of only two of the levels of diversity, which were used by the U.S. Air Force High Power Tropospheric Scatter long distance microwave transmissions. The other being two antennas, sending to the same distant ends.

I have no math or science experience to back this up other than it's my personal belief that many measured factors which are being calculated using formulas and test tools for EM Drives which are using waveguides as their input source. Would change in major ways. When using a horizontal or vertical polarity of the mounting position on or near the same mounting position used with the other polarity. For the same EM Drive. Which factors and/or how much. I have no idea.

I wish I had a better answer for you. But I think some of the test tools and/or formulas being used here if they have the ability to use input data using a different polarity for EM Drives using waveguide input as input data. That this would and could be quickly confirmed as fact or be ruled out as "Junk Science".

If I had any worries about this it would be. How accurately some test tools or formulas account for horizontal and vertical waveguide mounts to a Frustum, when calculating how the microwave transmission propagates.

I say this because of the Frustum cavity not being a normal cylinder. So the polarity of how the waveguide is mounted on a Frustum cavity would predispose the initial microwave transmission as it's leaving the waveguide, to less or more of the Frustum cavity wall angle changes based on the polarity of how the waveguide was mounted. Because of the waveguide being a rectangle and not a square. 

I can't see how that would not change how the microwave transmission propagated when the waveguide polarity is changed from horizontal to vertical or vise versa.

For me to simply disregard what polarity the waveguide entered the Frustum cavity for testing purposes. Would be equal to saying if you added or removed 2 inches in length to a Frustum that one would not see any noticeable test result differences. Which I think virtually everyone here would say would be an incorrect assumption.

A funny aside when saying "My EM Drive used a waveguide with a horizontal polarity" We need to create a common reference to should the waveguide polarity be considered to be in reference to the small and large end of a Frustum or the sides of a Frustum. My vote is to use the small and large ends as the reference point as what polarity a waveguide is using to enter a Frustum.
 
Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 03:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415593#msg1415593">Quote from: ramachandra on 08/12/2015 03:00 PM</a>
I am a Newbie and a lurker I bow to all of you for your unbounded enthusiasm and hardwork. While I am not a DIYer, I have been following with all the DIY projects. I have a humble suggestion.
I was changing the parameters in the McCalloch Thrust calculation Spreadsheet. (Excellent work!)
By having the same power and changing the geometry and size of the frustum, more than 1 N can be achived, it looks like.
(Changed based on Juan 2 corrected values)
      
                       Updated
Input               Reference Value
Big Diameter   28
Small Diameter   1
Cavity Length   100
Q                 5000
Frequency           2.45
Power          1000
Big Radius          14
Small Radius   0.5
   
mN Force          1608.75
mN Force         1081.08
mN Force         1025.45

This could prove the validity of McCalloch calculations.
Just a humble suggestion.

Welcome to the forum.  :)

Unfortunately McCulloch has many formulas that are different from the one in the spreadsheet.  See his blog for all his formulas:

http://physicsfromtheedge.blogspot.com/

I noticed that in the above calculation the length is 100 times the small diameter.

To confuse the problem further, besides having more than one formula, McCulloch in his blog has written that large length/diameter ratios are bad for actual thrust.  Since McCulloch has a number of formulas I suggest that you post your above suggestion as a question in his blog and see what McCulloch responds, as he is pretty good at answering questions.

If he answers you, I would appreciate your posting back here at NSF and letting us know what he answered.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/12/2015 03:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415590#msg1415590">Quote from: TenKen on 08/12/2015 02:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415584#msg1415584">Quote from: rfmwguy on 08/12/2015 02:28 PM</a>
NSF-1701 live test...Galinstan ordered and should be here within a week. Will do the live test either 8/18 or 8/25 depending on the delivery.

I think X_Ray asked this earlier but I didn't see your response: do you have any plans to record your tests, so people who aren't able to watch it live can still watch the video?  (Depending on what streaming program you're using, this may be a built-in function.)
Yes, I think I can record on Ustream as I do it. If I cannot, I'll simply do a recorded video.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: LasJayhawk on 08/12/2015 04:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
...
Note: I just can't help having "flashbacks" to my U.S. Air Force days as a Wideband Communications Equipment 304x0 equipment repair person (http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA201690) in the 1970's who maintained microwave equipment using near these same microwave frequencies.

One of my many maintenance duties was to replace desiccant in every waveguide we used and it was not simply to avoid only rust and/or condensation, in those waveguides.

It has been awhile. But I think one of the reasons why we used desiccant and replaced it so often in all our waveguides had to do with standing waves. I could be remembering this incorrectly. But that's what I recall today. That said. The situation I am referencing was at a site where our microwave transmit power was 10 KW per 60 foot parabolic antenna. Shown below.


Don

I would suspect the main reason was to prevent arcing in the waveguide. It's pretty common to find desiccant in the X band aircraft weather radars operating above 6-7 KW but not in the lower powered ones...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/12/2015 04:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415609#msg1415609">Quote from: LasJayhawk on 08/12/2015 04:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415549#msg1415549">Quote from: TheUberOverLord on 08/12/2015 12:44 PM</a>
...
Note: I just can't help having "flashbacks" to my U.S. Air Force days as a Wideband Communications Equipment 304x0 equipment repair person (http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA201690) in the 1970's who maintained microwave equipment using near these same microwave frequencies.

One of my many maintenance duties was to replace desiccant in every waveguide we used and it was not simply to avoid only rust and/or condensation, in those waveguides.

It has been awhile. But I think one of the reasons why we used desiccant and replaced it so often in all our waveguides had to do with standing waves. I could be remembering this incorrectly. But that's what I recall today. That said. The situation I am referencing was at a site where our microwave transmit power was 10 KW per 60 foot parabolic antenna. Shown below.


Don

I would suspect the main reason was to prevent arcing in the waveguide. It's pretty common to find desiccant in the X band aircraft weather radars operating above 6-7 KW but not in the lower powered ones...

Yes, that was also one of the reasons but as I stated in my prior post I seem to recall it helping with standing waves as well. So it was not simply for condensation reasons but also for RH water vapor reasons in the waveguide.

Again, I could be wrong about this but this is what I recall today. Many decades later.

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/12/2015 04:37 PM
So what did you use? Just a bag of desiccant sitting in the wave guide? How big?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/12/2015 04:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415616#msg1415616">Quote from: aero on 08/12/2015 04:37 PM</a>
So what did you use? Just a bag of desiccant sitting in the wave guide? How big?

Sometimes simply a bag of desiccant about the size of a sugar packet in a restaurant. Other times raw desiccant powder of varying quantities which had it's own pouch that also needed to be replaced when the desiccant was replaced.

Desiccant quantity would depend on the type of waveguide, how the waveguide ran vertically or horizontally and for how long of a distance.

Generally, minus the bendable waveguide runs to the antennas. The moment a waveguide went from vertical to horizontal after the initial waveguide bend a new section of waveguide would be used. Which is where virtually all the desiccant was located and placed.

Don   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/12/2015 05:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415604#msg1415604">Quote from: rfmwguy on 08/12/2015 03:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415590#msg1415590">Quote from: TenKen on 08/12/2015 02:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415584#msg1415584">Quote from: rfmwguy on 08/12/2015 02:28 PM</a>
NSF-1701 live test...Galinstan ordered and should be here within a week. Will do the live test either 8/18 or 8/25 depending on the delivery.

I think X_Ray asked this earlier but I didn't see your response: do you have any plans to record your tests, so people who aren't able to watch it live can still watch the video?  (Depending on what streaming program you're using, this may be a built-in function.)
Yes, I think I can record on Ustream as I do it. If I cannot, I'll simply do a recorded video.
Frustumapaloosa?!  :D

If the timing's right, you, Shells and TT could put on a show!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/12/2015 06:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415541#msg1415541">Quote from: SeeShells on 08/12/2015 12:24 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415497#msg1415497">Quote from: X_RaY on 08/12/2015 07:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415412#msg1415412">Quote from: SeeShells on 08/11/2015 11:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415408#msg1415408">Quote from: Rodal on 08/11/2015 11:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415404#msg1415404">Quote from: rfmwguy on 08/11/2015 10:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415343#msg1415343">Quote from: deltaMass on 08/11/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415341#msg1415341">Quote from: X_RaY on 08/11/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415340#msg1415340">Quote from: deltaMass on 08/11/2015 07:04 PM</a>
About PaulTheSwag's experiment:
1. What differentiates the thrust profile from one where only an initial impulse was produced?
2. What is a "double knife-edge fulcrum"? It makes no sense to me.
3. Do we know the power value?

2. Did you saw the pictures? http://imgur.com/a/iO7er
OK. I now understand the double knife edge (actually triple).
Same as mine, 3 blades, 2 balance points.
(charlescalebcolton203963.jpg)
Two balance points for me.
Shell your bearing is able to produce a lot of friction..  ???
What do you think about commercial bearings for your carbon construction? metal, plastic or ceramic
It could if I wasn't using a trick here that I needed to mention and I'm really sorry it slipped my mind. The knife edge really isn't a knife edge anymore, it has been rounded off using a belt sander and the tube simply rolls over the rounded surface of the blade that was a sharp edge.

I liked the strength of the blade but I disliked the friction and stresses when using 2 blades one on top of each other or the way the blade could slice into a metal or a carbon fiber tube. In testing I had the blades chip and shatter against each other and glued steel plates end up getting a grove from the blade in just a couple runs up and down with weights on the fulcrum.

A mental calculation thinking about the small radii the tube would roll over changing the length over 1 meter was around 5 microns. It's acceptable.

Added: What do you think xray? Do you think this will work ok? I wanted to try and avoid any bearing for they seem to always have the issued of initial movement from stiction.
The stiction at initial movement is inherent for any conventional bearing. Rounded blades will work better i think, use a drop of oil and all will be good :)
Ball-bearing is even better...

picture source:http://www.gsstoedtlen.homepage.t-online.de/rad/geschichte_rad3.htm

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/12/2015 06:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415593#msg1415593">Quote from: ramachandra on 08/12/2015 03:00 PM</a>
I am a Newbie and a lurker I bow to all of you for your unbounded enthusiasm and hardwork. While I am not a DIYer, I have been following with all the DIY projects. I have a humble suggestion.
I was changing the parameters in the McCalloch Thrust calculation Spreadsheet. (Excellent work!)
By having the same power and changing the geometry and size of the frustum, more than 1 N can be achived, it looks like.
(Changed based on Juan 2 corrected values)
      
                       Updated
Input               Reference Value
Big Diameter   28
Small Diameter   1
Cavity Length   100
Q                 5000
Frequency           2.45
Power          1000
Big Radius          14
Small Radius   0.5
   
mN Force          1608.75
mN Force         1081.08
mN Force         1025.45

This could prove the validity of McCalloch calculations.
Just a humble suggestion.

Did you plug the same values into @Notsosureofit's equation and see how it compares? His equation is more likely correct than McCulloch's.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 06:38 PM
[quote author=TheUberOverLord link=topic=38203.msg1415594#msg1415594

Should have said insertion points for the waveguide instead.
Each will excite a different mode.
Top magnetron

Side magnetron waveguide

Dual Dipoles top

sw-structure.jpg
Opposing RF injection points


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/12/2015 06:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415631#msg1415631">Quote from: deltaMass on 08/12/2015 05:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415604#msg1415604">Quote from: rfmwguy on 08/12/2015 03:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415590#msg1415590">Quote from: TenKen on 08/12/2015 02:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415584#msg1415584">Quote from: rfmwguy on 08/12/2015 02:28 PM</a>
NSF-1701 live test...Galinstan ordered and should be here within a week. Will do the live test either 8/18 or 8/25 depending on the delivery.

I think X_Ray asked this earlier but I didn't see your response: do you have any plans to record your tests, so people who aren't able to watch it live can still watch the video?  (Depending on what streaming program you're using, this may be a built-in function.)
Yes, I think I can record on Ustream as I do it. If I cannot, I'll simply do a recorded video.
Frustumapaloosa?!  :D

If the timing's right, you, Shells and TT could put on a show!
There you go...might be as interesting as most the stuff on basic cable ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 07:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415631#msg1415631">Quote from: deltaMass on 08/12/2015 05:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415604#msg1415604">Quote from: rfmwguy on 08/12/2015 03:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415590#msg1415590">Quote from: TenKen on 08/12/2015 02:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415584#msg1415584">Quote from: rfmwguy on 08/12/2015 02:28 PM</a>
NSF-1701 live test...Galinstan ordered and should be here within a week. Will do the live test either 8/18 or 8/25 depending on the delivery.

I think X_Ray asked this earlier but I didn't see your response: do you have any plans to record your tests, so people who aren't able to watch it live can still watch the video?  (Depending on what streaming program you're using, this may be a built-in function.)
Yes, I think I can record on Ustream as I do it. If I cannot, I'll simply do a recorded video.
Frustumapaloosa?!  :D

If the timing's right, you, Shells and TT could put on a show!
I'm pushing as hard as I can. ;)

Would be a great show.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/12/2015 07:22 PM
http://cas.web.cern.ch/cas/Germany2009/Lectures/PDF-Web/Jensen.pdf

Back to the grind
good reading...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/12/2015 07:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415653#msg1415653">Quote from: SeeShells on 08/12/2015 06:38 PM</a>
[quote author=TheUberOverLord link=topic=38203.msg1415594#msg1415594

Should have said insertion points for the waveguide instead.
Each will excite a different mode.
Top magnetron

Side magnetron waveguide

Dual Dipoles top

sw-structure.jpg
Opposing RF injection points
Your flexible cone is a good idea i think!
All the modes are excitable, more or less good with the antenna at each position/orientation.
VNA wide band measurements show that.(it is hard work to suppress a resonance nearly complete) ;)
At a wrong position and/or orientation you will see only a little dip in the plot. Better you look in the complex xy-plane (Magnitude and Phase or Re/Im).
Over- as under- coupling looks equal in a simple magnitude/frequency plot!
You are able to change the length, that is need to get resonance for the different modes (and high Q).
It's a good plan and i am sure a lot of work!
Can you post some pictures of the present state? Would be very interesting.

picture 1: coplanar transmission line with sonnetEM
pictures 2 and 3: magnitude vs complex

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/12/2015 07:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415677#msg1415677">Quote from: SeeShells on 08/12/2015 07:22 PM</a>
http://cas.web.cern.ch/cas/Germany2009/Lectures/PDF-Web/Jensen.pdf

Back to the grind
good reading...
It's a very nice read. Notice that, because the R,L,C components in the cavity model are in shunt configuration, the usual expression for Q is reciprocated (e.g. Q = R/(w L) ). Also note that maximum attainable Q's (non-superconducting) are pegged around 41,000.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/12/2015 07:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415691#msg1415691">Quote from: deltaMass on 08/12/2015 07:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415677#msg1415677">Quote from: SeeShells on 08/12/2015 07:22 PM</a>
http://cas.web.cern.ch/cas/Germany2009/Lectures/PDF-Web/Jensen.pdf

Back to the grind
good reading...
It's a very nice read. Notice that, because the R,L,C components in the cavity model are in shunt configuration, the usual expression for Q is reciprocated (e.g. Q = R/(w L) ). Also note that maximum attainable Q's (non-superconducting) are pegged around 41,000.
The file looks good! Thanks for the quote

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ramachandra on 08/12/2015 08:09 PM
Hi
This is what Mike McCulloch had replied
//Dear Ramachandra, The formula I published, and that you are using, was an approximation that assumed the Unruh waves can only resonate perpendicular to the emdrive's cavity axis. This is an approximation because the Unruh waves can also resonate along the axis, and in diagonal directions. If you had a pointed cone, this formula would then predict no waves at all at the pointed end, and an infinite thrust since Wsmall=0, but in the real emdrive Unruh waves would still be able to exist at the small end by resonating along the length of the axis. This limitation of the formula is not so bad for the emdrive because it is a truncated cone, but a better formula is needed and I've been trying to calculate the exact analytic formula to take account of resonance in all directions. In lieu of that I've developed a simple formula that does take account of resonance along the axis. It is:

F = 6PQL/c * ( 1/(L+4wb) - 1/(L+4ws) )

L=axial length. You can also see my discussion of this formula here:

http://physicsfromtheedge.blogspot.co.uk/2015/02/mihsc-vs-emdrive-data-3d.html//

As for these calculations, the original post did contain those numbers
mN Force          1608.75
mN Force         1081.08
mN Force         1025.45
These three numbers are from three of his equations.

When I put these numbers in @notsureofit xls
Big Diameter   28
Small Diameter   1
Cavity Length   100
Q                 5000
Frequency           2.45
Power          1000

I get 1144  mN!

But If I keep the original length 0.164m, i get 6980 mN.

Such testing could prove which one can be counted on.
Just a suggestion.

 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 08:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415616#msg1415616">Quote from: aero on 08/12/2015 04:37 PM</a>
So what did you use? Just a bag of desiccant sitting in the wave guide? How big?

aero, the csv files you run for:

\\64 cycle Shell 2D loop ant \\ 64-cycle-run 2d loop ant-csv \\ 2-d-loop64

show a TE (transverse electric) mode.

Unfortunately, we cannot tell for sure what mode it is unless we get a circular cross-section (with normal z) at a location away from the bases.  The reason for this is that the electric modes in the transverse direction are zero at the bases due to the boundary conditions.  (This was not a problem for TM mode shapes because the transverse magnetic field is not zero at the bases)

I would like the same information (all 6 fields, using the same mesh, etc.) as for the other runs at the following location,  for a circular cross-section (with normal z):

Column 30(columns ranging from 0 to 228)

in order to ascertain what TE mode shape it is

If you have to re-run, it may be advantageous to re-run for the regular amount of time instead of 64 cycles because that way we can accomplish two things:

1) ascertain what TE mode shape it is

2) compare the stresses, forces, etc at the bases and the Poynting vector in the trapezium plane with the previous runs for Yang Shell that had transverse magnetic modes

Thanks

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/12/2015 08:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415691#msg1415691">Quote from: deltaMass on 08/12/2015 07:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415677#msg1415677">Quote from: SeeShells on 08/12/2015 07:22 PM</a>
http://cas.web.cern.ch/cas/Germany2009/Lectures/PDF-Web/Jensen.pdf

Back to the grind
good reading...
It's a very nice read. Notice that, because the R,L,C components in the cavity model are in shunt configuration, the usual expression for Q is reciprocated (e.g. Q = R/(w L) ). Also note that maximum attainable Q's (non-superconducting) are pegged around 41,000.

If you think those dual ported cavity designs are like a non ported and unloaded EMDrive cavity well good luck.

BTW that looks like a Superfish field drawing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: arc on 08/12/2015 09:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414429#msg1414429">Quote from: Star One on 08/08/2015 08:06 PM</a>
By the way those of you supporting the EM drive want an example of a theory that started out on the fringes but has gradually moved more centre wise then they only have to look at holographic theory for the universe.

http://www.sciencedaily.com/releases/2015/04/150427101633.htm

Is that theory the one that leads down the path to...  everything around us including us is just a simulation.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/12/2015 09:40 PM
Looks like I am going to be interviewed on a live radio talk show about my NSF-1701 experiment in the near future. When it becomes finalized, I'll post the info I have. Can't discuss any details yet...

They always said I had a Face made for the Radio ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/12/2015 09:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415712#msg1415712">Quote from: arc on 08/12/2015 09:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414429#msg1414429">Quote from: Star One on 08/08/2015 08:06 PM</a>
By the way those of you supporting the EM drive want an example of a theory that started out on the fringes but has gradually moved more centre wise then they only have to look at holographic theory for the universe.

http://www.sciencedaily.com/releases/2015/04/150427101633.htm

Is that theory the one that leads down the path to...  everything around us including us is just a simulation.
Actually, no. They are separate. But note that they are not mutually exclusive  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: arc on 08/12/2015 09:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1414622#msg1414622">Quote from: TheTraveller on 08/09/2015 04:11 PM</a>
Interesting Russian EMDrive like patent:
http://bankpatentov.ru/node/123593

and comment received on Reddit EMDrive forum:
https://www.reddit.com/r/EmDrive/comments/3ceyjv/email_from_roger_shawyer/ctww6rd

As Dr. Vladimir Leonov claims the "Shawyer Effect" works via the QV, Dr. White might be interested.

Yes Interesting
(snip)
...The invention relates to the space industry and is designed to create traction in the new generations of interplanetary spacecraft by using superstrong interactions with the vacuum field. The proposed method of propulsion is carried out in a vacuum due to redistribution of medium density quantum vacuum field within the working fluid in a direction opposite to the vector thrust by deformation of the vacuum field, acting on the working fluid system of rotating non-uniform electric and magnetic fields of skew, intensity gradient of which coincides with the direction thrust vector, and the working fluid is set at the same time, electric and magnetic properties. According to the first embodiment of the motor field for a spacecraft equipped with a generator, the voltage converter and activators vacuum field comprising a motor rotor formed as a working fluid of a dielectric and ferromagnetic material in the shape of a truncated cone, the base of which is coaxially aligned with the rotor of the motor, advantageously giromotora, magnetic system bipolar electrodes that cover a clearance taper working fluid. In a second embodiment of the field drive for spacecraft includes a housing field engine that serves as the body of the spacecraft, equipped with activators of the vacuum field, ring generator, battery, battery current converter, traction control field Motor, motors to drive the rotor activators vacuum field. ..
(snip)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/12/2015 09:59 PM
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 10:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

That's an interesting shape!
How did you calculate <<Resonance at 2.45 GHz in TE013 mode>> ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/12/2015 10:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415724#msg1415724">Quote from: Rodal on 08/12/2015 10:03 PM</a>
That's an interesting shape!
How did you calculate <<Resonance at 2.45 GHz in TE013 mode>> ?

Thanks doc!
I used TheTraveller's latest's spreadsheet (http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools) to tune the various dimensions. I do not know any software or technique to do those calcs.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/12/2015 10:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415726#msg1415726">Quote from: flux_capacitor on 08/12/2015 10:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415724#msg1415724">Quote from: Rodal on 08/12/2015 10:03 PM</a>
That's an interesting shape!
How did you calculate <<Resonance at 2.45 GHz in TE013 mode>> ?

Thanks doc!
I used TheTraveller's latest's spreadsheet (http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools) to tune the various dimensions. I do not know any software or technique to do those calcs.
It is quite an interesting shape to explore for example whether there is a limit to the notion of large angles and proximity to the base. I will calculate the attenuation shape, Q and resonance when I have a chance :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Kenjee on 08/12/2015 11:37 PM
Sorry for crashing in but I must ask.
Is Neon light usefull for detecting RF leaks outside frustum?

Sorry if it`s been proposed.

Keep up, we are counting on you! :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/12/2015 11:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415747#msg1415747">Quote from: Kenjee on 08/12/2015 11:37 PM</a>
Sorry for crashing in but I must ask.
Is Neon light usefull for detecting RF leaks outside frustum?

Sorry if it`s been proposed.

Keep up, we are counting on you! :)
From what I have seen, a neon tube must be almost in contact with the source. Not a good idea.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Kenjee on 08/13/2015 12:22 AM
Well :(

But there are some crazy rigs:

https://www.youtube.com/watch?v=NIjcNIR_Yg8

https://www.youtube.com/watch?v=_fqYusKZC38
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 12:25 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415715#msg1415715">Quote from: rfmwguy on 08/12/2015 09:40 PM</a>
Looks like I am going to be interviewed on a live radio talk show about my NSF-1701 experiment in the near future. When it becomes finalized, I'll post the info I have. Can't discuss any details yet...

They always said I had a Face made for the Radio ;)

I just asked him for details and I might do it with you. No weirdness and space aliens allowed. ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 12:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415368#msg1415368">Quote from: aero on 08/11/2015 08:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.

bluered (opaque blue to transparent white to opaque red). I have several color maps available, this is just the first try. I personally don't like it very much.
Some of these images seem wrong.

Example:

bighz

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055446,3Bimage.pagespeed.ic.JnWBLMhTwp.webp)

as I interpret this, it is the Hz field, the magnetic field normal to the Big Base, with the z axis longitudinal, normal to the Big Base.

the magnetic field normal to a surface should be zero at a surface.  It should be zero at the Big Base.
It is close to zero when I post-process the csv files with Wolfram Mathematica

Yet in the above images you show this bighz as having the highest magnitude magnetic field at the Big Base?
Ditto for smallhz

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055434,3Bimage.pagespeed.ic.1L14N7WegQ.webp)

_____________

PS: I verified that the end cuts:

End cuts are at:     Big end ­­ .h5 row 15

                            Small end ­­ .h5 row 214

are at the correct location, so that is not the source of the problem.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/13/2015 12:45 AM
Have decided to dump 9kgs of rotary table mass by using 1kg of Lithium Ion rechargeable batteries (28 x 3.7v 3.8Ah = approx 400Whs of energy) instead of 7kgs of SLA batteries and reduce the frustum thickness from 2mm (4.2kg) to 0.5mm (1kg).

Expected frustum temp rise and pressure calcs show 0.5mm sidewall and end plate thickness is more than enough.

Should now take about 2 minutes per 30 rpm increase versus 4 minutes at the old mass.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/13/2015 12:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

Glad you found the spreadsheet useful. Using Goal Seek has made it super fast to find the exact resonance in the desired mode or not.

Interesting design.

As I understand the momenta gradient driven opposite Frustum movement and resultant Force vectors, they "PUSH" the frustum from the outer big end edge toward the vertex. Would not this design result in a lot of Force vectors pushing toward the vertex but not really helping axial Force generation so much?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/13/2015 01:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

I might be able to model it.  Can you export an STL of the part?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/13/2015 01:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415753#msg1415753">Quote from: Rodal on 08/13/2015 12:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415368#msg1415368">Quote from: aero on 08/11/2015 08:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415364#msg1415364">Quote from: aero on 08/11/2015 08:37 PM</a>
Dr. Rodal,

I was trying to figure out a way to communicate what I thought was going on, but I think I was wrong. It's simple -

Draw 3 sine waves on a sheet of paper, x-y axis, each symmetric about the x axis, but with different amplitudes. Then draw horizontal lines tangent to the extreme positive and negative values of each sine wave. I used the y value of the top and bottom horizontal line.

So the weaker sign waves are not clipped, they just don't have enough power to show up on the scale of the strongest.

I'll see about using a different color map.

bluered (opaque blue to transparent white to opaque red). I have several color maps available, this is just the first try. I personally don't like it very much.
Some of these images seem wrong.

Example:

bighz

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055446,3Bimage.pagespeed.ic.JnWBLMhTwp.webp)

as I interpret this, it is the Hz field, the magnetic field normal to the Big Base

the magnetic field normal to a surface should be zero at a surface.  It should be zero at the Big Base.
It is close to zero when I post-process the csv files with Wolfram Mathematica

Yet in the above images you show this bighz as having the highest magnitude magnetic field at the Big Base?
Ditto for smallhz

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055434,3Bimage.pagespeed.ic.1L14N7WegQ.webp)

Interesting - We'll need to wait until Imbfan gets the automated field intensity extraction software running. That won't be to long based on the progress she is making.

Earlier today I was looking at the field intensity of the images around the base ends using hdfview. It seems clear from looking at adjacent slices that something may be not right. See the attached jpgs for z slice 14, 15, 16 and 17. Slice z-14 is within the metal, so nothing. Slice z-15 is the cut we have been taking as at the big base, while z-16 is one pixel inward and z-17 is 2 pixels inward.  With the lattice measuring 0.275 meters (rounded up in deference to DeltaMass) and resolution 250, the distance between pixels is 1.1 mm so z-15 should be well out of the metal if z-14 is the metal surface. But the images seem to say that z-14 is well inside the metal and z-15 is somewhere close to the surface while z-16 is well outside the metal.

I wonder if the meep "subpixel averaging" is blending the dielectric constant at the edge of the metal with the air, also at the edge? If so, maybe I should quit using "subpixel averaging." On the other hand, the characteristic you wrote about above seems different than the one I observed.

Let's see what it looks like when the field intensities are automatically and correctly extracted for the images. Then we'll have something that we can fix, if it is broken. Fixing my fat fingers is much more difficult and they are not even broken - yet  :o

P.S. I see you looked at this while I was typing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 01:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415752#msg1415752">Quote from: SeeShells on 08/13/2015 12:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415715#msg1415715">Quote from: rfmwguy on 08/12/2015 09:40 PM</a>
Looks like I am going to be interviewed on a live radio talk show about my NSF-1701 experiment in the near future. When it becomes finalized, I'll post the info I have. Can't discuss any details yet...

They always said I had a Face made for the Radio ;)

I just asked him for details and I might do it with you. No weirdness and space aliens allowed. ;)
That's a fact...he just called and said it might be tonight...will call me back in abt 1 hr. Love to have you there as well. Told them my belief was seeing is believing...not willing to take others word on it. had to try it for myself.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/13/2015 01:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415765#msg1415765">Quote from: rfmwguy on 08/13/2015 01:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415752#msg1415752">Quote from: SeeShells on 08/13/2015 12:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415715#msg1415715">Quote from: rfmwguy on 08/12/2015 09:40 PM</a>
Looks like I am going to be interviewed on a live radio talk show about my NSF-1701 experiment in the near future. When it becomes finalized, I'll post the info I have. Can't discuss any details yet...

They always said I had a Face made for the Radio ;)

I just asked him for details and I might do it with you. No weirdness and space aliens allowed. ;)
That's a fact...he just called and said it might be tonight...will call me back in abt 1 hr. Love to have you there as well. Told them my belief was seeing is believing...not willing to take others word on it. had to try it for myself.

Don't suppose we'll be able to listen or you record? Likely will be copyrighted.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 01:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415766#msg1415766">Quote from: aero on 08/13/2015 01:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415765#msg1415765">Quote from: rfmwguy on 08/13/2015 01:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415752#msg1415752">Quote from: SeeShells on 08/13/2015 12:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415715#msg1415715">Quote from: rfmwguy on 08/12/2015 09:40 PM</a>
Looks like I am going to be interviewed on a live radio talk show about my NSF-1701 experiment in the near future. When it becomes finalized, I'll post the info I have. Can't discuss any details yet...

They always said I had a Face made for the Radio ;)

I just asked him for details and I might do it with you. No weirdness and space aliens allowed. ;)
That's a fact...he just called and said it might be tonight...will call me back in abt 1 hr. Love to have you there as well. Told them my belief was seeing is believing...not willing to take others word on it. had to try it for myself.

Don't suppose we'll be able to listen or you record? Likely will be copyrighted.
I suppose that rfmwguy is the legal owner of whatever he produces, including what he speaks and articulates. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 01:52 AM
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

Guest info to appear tomorrow abt 7:30 PM on othersideofmidnight.com website

Show is a mixture of science fiction, fantasy and science fact...I'll stay with facts and hope to still be entertaining, but understand its show biz. Will not over promise and under deliver however ;)

Its late for sure but they archive shows. Will talk how and why I jumped in and where it could lead.

Sounds like fun...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: LasJayhawk on 08/13/2015 02:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

Guest info to appear tomorrow abt 7:30 PM on othersideofmidnight.com website

Show is a mixture of science fiction, fantasy and science fact...I'll stay with facts and hope to still be entertaining, but understand its show biz. Will not over promise and under deliver however ;)

Its late for sure but they archive shows. Will talk how and why I jumped in and where it could lead.

Sounds like fun...

Even money says Art brings up UFO's in the first 5 min.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 02:51 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415774#msg1415774">Quote from: LasJayhawk on 08/13/2015 02:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

Guest info to appear tomorrow abt 7:30 PM on othersideofmidnight.com website

Show is a mixture of science fiction, fantasy and science fact...I'll stay with facts and hope to still be entertaining, but understand its show biz. Will not over promise and under deliver however ;)

Its late for sure but they archive shows. Will talk how and why I jumped in and where it could lead.

Sounds like fun...

Even money says Art brings up UFO's in the first 5 min.
Course my reply would be I will believe it when I see it personally ;)

Sorta the reason I started my build...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 03:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415777#msg1415777">Quote from: rfmwguy on 08/13/2015 02:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415774#msg1415774">Quote from: LasJayhawk on 08/13/2015 02:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

Guest info to appear tomorrow abt 7:30 PM on othersideofmidnight.com website

Show is a mixture of science fiction, fantasy and science fact...I'll stay with facts and hope to still be entertaining, but understand its show biz. Will not over promise and under deliver however ;)

Its late for sure but they archive shows. Will talk how and why I jumped in and where it could lead.

Sounds like fun...

Even money says Art brings up UFO's in the first 5 min.
Course my reply would be I will believe it when I see it personally ;)

Sorta the reason I started my build...
Be prepared what to answer if he asks you:

1) Whether Shawyer invented the EM Drive as a result of a close encounter of the 3rd kind with UFO's that allowed him to get access to UFO's propulsion technology?

2) Whether the EM Drive is derived from Die Glocke  Wunderwaffe antigravity research from WWII ?

3) What are you going to do if you accidentally create a wormhole in your garage as a result of your EM Drive research

4) if the EM Drive works, how long will a trip to Alpha Centauri take.

 :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/13/2015 03:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415780#msg1415780">Quote from: Rodal on 08/13/2015 03:06 AM</a>
Be prepared what to answer if he asks you:

1) Whether Shawyer invented the EM Drive as a result of a close encounter of the 3rd kind with UFO's that allowed him to get access to UFO's propulsion technology?
Art has been doing this a long time.  Surely he knows the UFOs use Zero time zero space motion frozen 500KV (DC) repulsive electrostatic counter rotating vortexes in glass and copper plate capacitors radially around a central magnetic generator.  Everyone knows that, right?*

Ref:
Supreme Cosmic Secret Vol. 1, p2, publisher unknown.

* One observes that the rotation of static fields is, by definition, proportional to Maxwell's 1880 rotation rate.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 04:27 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415764#msg1415764">Quote from: aero on 08/13/2015 01:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415753#msg1415753">Quote from: Rodal on 08/13/2015 12:33 AM</a>
...
Some of these images seem wrong.

Example:

bighz

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055446,3Bimage.pagespeed.ic.JnWBLMhTwp.webp)

as I interpret this, it is the Hz field, the magnetic field normal to the Big Base

the magnetic field normal to a surface should be zero at a surface.  It should be zero at the Big Base.
It is close to zero when I post-process the csv files with Wolfram Mathematica

Yet in the above images you show this bighz as having the highest magnitude magnetic field at the Big Base?
Ditto for smallhz

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1055434,3Bimage.pagespeed.ic.1L14N7WegQ.webp)

Interesting - We'll need to wait until Imbfan gets the automated field intensity extraction software running. That won't be to long based on the progress she is making.

Earlier today I was looking at the field intensity of the images around the base ends using hdfview. It seems clear from looking at adjacent slices that something may be not right. See the attached jpgs for z slice 14, 15, 16 and 17. Slice z-14 is within the metal, so nothing. Slice z-15 is the cut we have been taking as at the big base, while z-16 is one pixel inward and z-17 is 2 pixels inward.  With the lattice measuring 0.275 meters (rounded up in deference to DeltaMass) and resolution 250, the distance between pixels is 1.1 mm so z-15 should be well out of the metal if z-14 is the metal surface. But the images seem to say that z-14 is well inside the metal and z-15 is somewhere close to the surface while z-16 is well outside the metal.

I wonder if the meep "subpixel averaging" is blending the dielectric constant at the edge of the metal with the air, also at the edge? If so, maybe I should quit using "subpixel averaging." On the other hand, the characteristic you wrote about above seems different than the one I observed.

Let's see what it looks like when the field intensities are automatically and correctly extracted for the images. Then we'll have something that we can fix, if it is broken. Fixing my fat fingers is much more difficult and they are not even broken - yet  :o

P.S. I see you looked at this while I was typing.

Yes the Meep images are very wrong and misleading.  Actually HXz is the largest, and HYz is close, but HZz at the Big Base is practically zero (contrary to the Meep images output that have it as the largest).

HZz must be zero at the Big Base to satisfy the Boundary Condition that the normal magnetic field must be zero at a conductor.

See my attachments below (using Wolfram Mathematica to post-process the csv files) and compare with the Meep output.

NOTICE that my contour plots are rotated by 90 degress from your contour plots


It very much looks like the problem is due to the commands used to get the contour plots to be plotted within the same range.  The plot commands are doing the opposite of what should be done. The commands are incorrectly clipping the data: they are only allowing the small HZz component to have contour plots.

It very much looks like the problem is due to the wrong range commands used to get the contour plots to be plotted within the same range.  The plot commands are doing the opposite of what should be done. The commands are incorrectly clipping the data: they are only allowing the small HZz component to have contour plots.

The range used is the wrong range:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315

Quote from: aero
The ranges are from field components as follows:
# hx all data range from -0.000538633 to 0.000538633.     H field big end
 

The correct range for HXz at the big end is -0.013 to +0.013

The contour plots are being clipped !!!!


Clipping is the complete opposite of what should be done.  We are interested in the high values, not the low values !

QUESTION: At what time step did you output the pictures ?

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1055449;image)
(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1055447;image)
(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1055445;image)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/13/2015 05:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415764#msg1415764">Quote from: aero on 08/13/2015 01:23 AM</a>

Interesting - We'll need to wait until Imbfan gets the automated field intensity extraction software running. That won't be to long based on the progress she is making.

Please find a python file attached.  It works well on my machine using the flags presented before.  There remain some rough edges, but this should do the bulk of the work automagically.  Enjoy!

Quote
I wonder if the meep "subpixel averaging" is blending the dielectric constant at the edge of the metal with the air, also at the edge? If so, maybe I should quit using "subpixel averaging." On the other hand, the characteristic you wrote about above seems different than the one I observed.


I'm pretty sure this is exactly what is happening.  The boundary lies between pixels 14 and 16.  It's late otherwise I'd math it out.  If you don't subpixel average, the angled sides would go wonky, I bet.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/13/2015 05:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415757#msg1415757">Quote from: TheTraveller on 08/13/2015 12:57 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

Glad you found the spreadsheet useful. Using Goal Seek has made it super fast to find the exact resonance in the desired mode or not.

Interesting design.

As I understand the momenta gradient driven opposite Frustum movement and resultant Force vectors, they "PUSH" the frustum from the outer big end edge toward the vertex. Would not this design result in a lot of Force vectors pushing toward the vertex but not really helping axial Force generation so much?

Yes. Every force vector in an EmDrive with spherical ends has an inner component (yet the vector on the axis) since they all point towards the vertex. With a side wall angle > 45° this component is maybe too much. Maybe the wall would need to be less angled.

Whatever, I did that to explore "extreme shapes" and these kinds of possibilities:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415732#msg1415732">Quote from: Rodal on 08/12/2015 10:22 PM</a>
It is quite an interesting shape to explore for example whether there is a limit to the notion of large angles and proximity to the base. I will calculate the attenuation shape, Q and resonance when I have a chance :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/13/2015 07:46 AM
Using The Travellers spreadsheet to gauge resonance in the L-Band to compare with other modelling.
Frustrum Big Diameter 0.4335m
Frustrum Small Diameter 0.2461m
Frustrum Centre Length 0.3543m
Frequency: 932.3Hz - close to TM011 Mode? Am I using the spreadsheet as intended?
Any idea what Q you end up with given the larger frustrum at TM011?
Thoughts as to TM011 EM-Drive/Q-Thruster phenomena at TM011 (vs. say TM010)? Would go TE012 but looks hard to do in the L-Band according to this spreadsheet.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/13/2015 08:26 AM
Please take a look at the conclusion of the below paper, it may explain why we have a decreasing force in vacuum.
When the particles in air (water,soot...) disappear the force decrease. What do you think of that? It could be an explanation for the thin shell frustums.

Lateral Chirality-sorting Optical Spin Forces in Evanescent Fields

http://arxiv.org/abs/1408.2268

"The transverse component of the spin angular momentum of evanescent waves gives rise to lateral optical forces on chiral particles, which have the unusual property of acting in a direction in which there is neither a field gradient nor wave propagation."
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 11:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415794#msg1415794">Quote from: lmbfan on 08/13/2015 05:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415764#msg1415764">Quote from: aero on 08/13/2015 01:23 AM</a>

Interesting - We'll need to wait until Imbfan gets the automated field intensity extraction software running. That won't be to long based on the progress she is making.

Please find a python file attached.  It works well on my machine using the flags presented before.  There remain some rough edges, but this should do the bulk of the work automagically.  Enjoy!

Quote
I wonder if the meep "subpixel averaging" is blending the dielectric constant at the edge of the metal with the air, also at the edge? If so, maybe I should quit using "subpixel averaging." On the other hand, the characteristic you wrote about above seems different than the one I observed.


I'm pretty sure this is exactly what is happening.  The boundary lies between pixels 14 and 16.  It's late otherwise I'd math it out.  If you don't subpixel average, the angled sides would go wonky, I bet.

Subpixel averaging cannot be the cause of the problem because subpixel averaging should also affect the csv files, but as I show in message: http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415788#msg1415788  the csv files do NOT have this problem: the csv files correctly show the HZz magnetic field normal to the big base to have the lowest magnitude (instead of the highest), the csv files show it to have a magnitude close to zero, and it should be zero to satisfy the boundary conditions.

So, the problem has everything to do with the routine and commands used to make the plots: it is a post-processing problem, not a processing problem.  Since subpixel avearaging affects processing itself, it should affect the csv files output, and hence subpixel averaging cannot be the source of the problem.

It very much looks like the problem is due to the wrong range commands used to get the contour plots to be plotted within the same range.  The plot commands are doing the opposite of what should be done. The commands are incorrectly clipping the data: they are only allowing the small HZz component to have contour plots.

The range used is the wrong range:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315

Quote from: aero
The ranges are from field components as follows:
# hx all data range from -0.000538633 to 0.000538633.     H field big end
 

The correct range for HXz at the big end is -0.013 to +0.013

The contour plots are being clipped at a very low value!!!!


Clipping is the complete opposite of what should be done.  We are interested in the high values, not the low values !

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 11:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415780#msg1415780">Quote from: Rodal on 08/13/2015 03:06 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415777#msg1415777">Quote from: rfmwguy on 08/13/2015 02:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415774#msg1415774">Quote from: LasJayhawk on 08/13/2015 02:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

Guest info to appear tomorrow abt 7:30 PM on othersideofmidnight.com website

Show is a mixture of science fiction, fantasy and science fact...I'll stay with facts and hope to still be entertaining, but understand its show biz. Will not over promise and under deliver however ;)

Its late for sure but they archive shows. Will talk how and why I jumped in and where it could lead.

Sounds like fun...

Even money says Art brings up UFO's in the first 5 min.
Course my reply would be I will believe it when I see it personally ;)

Sorta the reason I started my build...
Be prepared what to answer if he asks you:

1) Whether Shawyer invented the EM Drive as a result of a close encounter of the 3rd kind with UFO's that allowed him to get access to UFO's propulsion technology?

2) Whether the EM Drive is derived from Die Glocke  Wunderwaffe antigravity research from WWII ?

3) What are you going to do if you accidentally create a wormhole in your garage as a result of your EM Drive research

4) if the EM Drive works, how long will a trip to Alpha Centauri take.

 :)
Lol...I've thought about that. Tho it will be my chance to get realistic conversation going, like let's get more data before we talk about a jetsons lifestyle ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 12:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415319#msg1415319">Quote from: Rodal on 08/11/2015 05:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415315#msg1415315">Quote from: aero on 08/11/2015 05:09 PM</a>
Here are the two png sets scaled to the maximum range of the E and H fields for the t=0 time slice. The ranges are from field components as follows:

# ez all data range from -0.000245405 to 0.000245405.     E field big end
# hx all data range from -0.000538633 to 0.000538633.     H field big end
# ez all data range from -4.04811e-05 to 4.04811e-05.     E field small end
# hy all data range from -0.000287974 to 0.000287974.     H field small end


Please look these png's over closely to be sure that this is what you want to see as it will be considerable effort to scale the png files in this way for the general case.

Or do you need to see the side views for this t = 0 case?

...
They look like ContourPlots in Mathematica when I use PlotRange with a range smaller than the full magnitude, so the contours get cliped.  I would double check whether magnitudes have not been clipped. 

3) Is there some means to control the number of contour values in the contour plots?  It looks to me like there are more contour levels than the number of colors available, as a result colors keep repeating themselves.  What one wants is to have blue represent the lowest magnitude and red the highest magnitude, instead of red/green/blue/yellow patterns being repeated cyclically.


Yes, this whole problem was due to the fact that the command was doing the complete opposite of what is wanted: it was clipping the images at a value of +/- 0.0005 and preventing showing the actual values that go up to +/-0.013, thus it was showing contours only for the contours that had values close to zero. 

Values were being clipped at 3.8% of the full range !  Anything higher than 3.8% was being clipped.

This error would have been evident if the numerical values of the contours would have been displayed, as I display them in the attachments to the message  http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415788#msg1415788

This error was not evident to anybody because the numerical values of the contours are not being shown in the Meep image output. This shows the problem with these Meep images output: nobody can tell what they mean, or even tell when there is an error because numerical values are not being shown.

To prevent future errors and to be able to interpret the images, the best thing would be to display the numerical values of the contours

It looks like somebody realized that there was an issue with this and they wrote about this in the Wiki about the need to have numerical values shown in the Meep contour plots:

http://emdrive.wiki/MEEP#Contour_plots

Quote from: EM Drive Wiki
Meep adventurers may wish to consider improving h5topng to produce images which contain: - The numerical value on the contour boundaries

(contour4.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 01:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415831#msg1415831">Quote from: rfmwguy on 08/13/2015 11:49 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415780#msg1415780">Quote from: Rodal on 08/13/2015 03:06 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415777#msg1415777">Quote from: rfmwguy on 08/13/2015 02:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415774#msg1415774">Quote from: LasJayhawk on 08/13/2015 02:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

Guest info to appear tomorrow abt 7:30 PM on othersideofmidnight.com website

Show is a mixture of science fiction, fantasy and science fact...I'll stay with facts and hope to still be entertaining, but understand its show biz. Will not over promise and under deliver however ;)

Its late for sure but they archive shows. Will talk how and why I jumped in and where it could lead.

Sounds like fun...

Even money says Art brings up UFO's in the first 5 min.
Course my reply would be I will believe it when I see it personally ;)

Sorta the reason I started my build...
Be prepared what to answer if he asks you:

1) Whether Shawyer invented the EM Drive as a result of a close encounter of the 3rd kind with UFO's that allowed him to get access to UFO's propulsion technology?

2) Whether the EM Drive is derived from Die Glocke  Wunderwaffe antigravity research from WWII ?

3) What are you going to do if you accidentally create a wormhole in your garage as a result of your EM Drive research

4) if the EM Drive works, how long will a trip to Alpha Centauri take.

 :)
Lol...I've thought about that. Tho it will be my chance to get realistic conversation going, like let's get more data before we talk about a jetsons lifestyle ;)
http://www.enterprisemission.com/

rfmwguy this is so much right up your alley, you have a great way with words (great voice and face for radio I might add). In a email to me he said he was going to try to get Shawyer on as well.

I think I'll pass this time.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 01:16 PM
Today is going to be a busy day. I have my final 2 sheets of melamine white pressed white 3/4" 4x8' sheets being picked up and with some help start to get them laid out to cut for the remaining pieces of the stand. I had to wait for help as they just are too heavy for one old gal to move around.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Warren Platts on 08/13/2015 01:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sghill on 08/13/2015 01:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

I love this.  I've been thinking about it since you first mentioned it too. 

It reminds me of those Mirage 3D hologram generators they sell in expensive toy stores, but with a hemispheric "lid" inserted into the top opening to keep the reflections going.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 02:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415851#msg1415851">Quote from: Warren Platts on 08/13/2015 01:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?
Yes.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 02:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415851#msg1415851">Quote from: Warren Platts on 08/13/2015 01:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?
Yes, PDT, 3 hours behind EST

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/13/2015 02:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415798#msg1415798">Quote from: flux_capacitor on 08/13/2015 05:59 AM</a>
.................

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

.....

Yes. Every force vector in an EmDrive with spherical ends has an inner component (yet the vector on the axis) since they all point towards the vertex. With a side wall angle > 45° this component is maybe too much. Maybe the wall would need to be less angled.

Whatever, I did that to explore "extreme shapes" and these kinds of possibilities:

How did you determine the very wide angle for this setup?

On the assumption that an EMdrive does indeed produce a force, there is still the problem that we do not know where and how that force is produced. There are a few theories but we still have to see some tests that are specifically designed to eliminate or confirm one of the theories.

Some say the side wall contribute nothing to the created force others say just the opposite.
Some say the Q is THE factor to achieve a large force, others claim a low Q but high attenuation is the path to follow.

First step is to confirm the existence of a force that makes the EMdrive move. Once that done, the different experiments should focus in lining up with certain theories and then test them to find out what theory fits best. This is why attenuation calculations on ever wider angles would be interesting. If the attenuation keeps growing with the angle, you would end up with 90° half-cone angle, which doesn't make sense.. hence why I suspect there must be an optimal angle... somewhere...( if attenuation is indeed the key factor for force creation)

For that, a certain standardization in design might be needed, but with each type of cavity designed to maximize certain theoretical ideas....(fe, increase of angle design, increasing Q design, etc)

Too bad i don't have a real metal 3dprinter to create a few standard cavity models.
The best i could do is 3Dprint in copper filament, but I doubt the copper particles would be dense enough to give solid internal reflection. The plastic part of the filament would melt way sooner and the particles would give a very lousy Q... :'(
Unless someone can convince me that is not the case....and that it does make sense..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 03:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415808#msg1415808">Quote from: OttO on 08/13/2015 08:26 AM</a>
Please take a look at the conclusion of the below paper, it may explain why we have a decreasing force in vacuum.
When the particles in air (water,soot...) disappear the force decrease. What do you think of that? It could be an explanation for the thin shell frustums.

Lateral Chirality-sorting Optical Spin Forces in Evanescent Fields

http://arxiv.org/abs/1408.2268

"The transverse component of the spin angular momentum of evanescent waves gives rise to lateral optical forces on chiral particles, which have the unusual property of acting in a direction in which there is neither a field gradient nor wave propagation."
I like this.... Thanks for the post.

Several on here bend towards the evanescent decaying waves that have four distinct momenta and three distinct spins compared to the single momentum and single spin for a propagating EM wave as to providing a link to the "outside world".

It's interesting that  traveling magnet can induce a action in a copper pipe.
http://video.mit.edu/watch/physics-demo-lenzs-law-with-copper-pipe-10268/

Coffee alert...
 
I theorise that the same is happening within the frustum with the traveling waves. We build up a DC magnetic component in the walls from the harmonic mode and when the mode collapses (they all have in every simulation) to form another mode. That switch decaying produces evanescent waves that push into the copper ~5um imparting momentum and force on the still decaying magnetic component left from the last mode.

It could be argued that the sum of the forces with mode changes and induced magnetic components in the side walls are zero with no net force using Maxwell's equations and be correct, although when one adds in the evanescent decaying waves that have four distinct momenta and three distinct spins things begin to look a little different and more complicated.  As to how a standard propagating wave with a single momentum and single spin inducing in the walls a normal magnetic Dc component induced into the walls can be acted upon from a evanescent decaying wave with an extraordinary grouping of forces? I stumble.

My math falls short here and I've reached my limit with my first cup of coffee anyway.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 03:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415867#msg1415867">Quote from: rfmwguy on 08/13/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415851#msg1415851">Quote from: Warren Platts on 08/13/2015 01:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?
Yes, PDT, 3 hours behind EST
LATE NITE, past my bedtime. :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/13/2015 04:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415870#msg1415870">Quote from: Flyby on 08/13/2015 02:55 PM</a>
How did you determine the very wide angle for this setup?
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415870#msg1415870">Quote from: Flyby on 08/13/2015 02:55 PM</a>
If the attenuation keeps growing with the angle, you would end up with 90° half-cone angle, which doesn't make sense.

Actually the 90° half-cone angle, thus the perfect half-sphere, was the value and the shape I started from ;)

I first chose Ds = 150 mm (to be just above the cylindrical cut-off diameter at 2.45 GHz),
and Db = 4x that value = 600 mm (arbitrarily, I just wanted to maximize the difference between the two end diameters).

So my "cavity" was at the beginning a perfect half-sphere of r2 = 300 mm… which could not resonate in TE013 mode (according to TT's spreadsheet) until I moved the ends a bit, slightly increasing the distance between them from 225 mm at the beginning to the optimal distance of 230.75 mm, keeping the end diameters constant. Hence the half-cone angle reduced from 90° initially to 77.18° after tweaking.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 04:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415874#msg1415874">Quote from: SeeShells on 08/13/2015 03:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415867#msg1415867">Quote from: rfmwguy on 08/13/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415851#msg1415851">Quote from: Warren Platts on 08/13/2015 01:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?
Yes, PDT, 3 hours behind EST
LATE NITE, past my bedtime. :)
Mine too, but I'll revert back to my college days one more time ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/13/2015 04:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415889#msg1415889">Quote from: rfmwguy on 08/13/2015 04:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415874#msg1415874">Quote from: SeeShells on 08/13/2015 03:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415867#msg1415867">Quote from: rfmwguy on 08/13/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415851#msg1415851">Quote from: Warren Platts on 08/13/2015 01:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?
Yes, PDT, 3 hours behind EST
LATE NITE, past my bedtime. :)
Mine too, but I'll revert back to my college days one more time ;)
Well you're younger than I am kiddo. ;) 60...HA!

If I wake up early I might join in but don't count your chickens.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/13/2015 05:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415761#msg1415761">Quote from: ElizabethGreene on 08/13/2015 01:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

I might be able to model it.  Can you export an STL of the part?

Although SketchUp is not good at all with circles (it draws them as a series of segments) I updated the number of segments per circle from 24 to 240 in order to improve precision.

I don't know if you need the 2D plan or the 3D modeled object, so I created both versions and exported them in STL format. You can find them zipped below.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/13/2015 05:26 PM
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 05:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415891#msg1415891">Quote from: SeeShells on 08/13/2015 04:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415889#msg1415889">Quote from: rfmwguy on 08/13/2015 04:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415874#msg1415874">Quote from: SeeShells on 08/13/2015 03:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415867#msg1415867">Quote from: rfmwguy on 08/13/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415851#msg1415851">Quote from: Warren Platts on 08/13/2015 01:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415769#msg1415769">Quote from: rfmwguy on 08/13/2015 01:52 AM</a>
Will be talking NSF-1701 on art bells dark matters digital radio network tomorrow at midnight PST.

PST? Did you mean midnight Pacific Daylight Time?
Yes, PDT, 3 hours behind EST
LATE NITE, past my bedtime. :)
Mine too, but I'll revert back to my college days one more time ;)
Well you're younger than I am kiddo. ;) 60...HA!

If I wake up early I might join in but don't count your chickens.
Too bad if you dont skype in...they mentioned they'd like to get more perspectives on builders and I mentioned you. Think if people hear realistic, serious stories on theory and build, it'll let them know its not a fringe element working on these things. Right now, my thought is many think it is another cold-fusion type device. Lots of notions to clear up. Seems like a good place to start...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 06:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415900#msg1415900">Quote from: flux_capacitor on 08/13/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415761#msg1415761">Quote from: ElizabethGreene on 08/13/2015 01:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

I might be able to model it.  Can you export an STL of the part?

Although SketchUp is not good at all with circles (it draws them as a series of segments) I updated the number of segments per circle from 24 to 240 in order to improve precision.

I don't know if you need the 2D plan or the 3D modeled object, so I created both versions and exported them in STL format. You can find them zipped below.

This is a very interesting shape to test the outer limits of the theories and methods involved.
Due to the extreme spherical conical shape of this cavity, the limitations of the spreadsheet approach (that in a kludgy way intends to model a spherical cone as a large series of cylindrical waveguides) is more crudely exposed:

the natural frequency of mode TE013 is 2.132 GHz (instead of 2.45 GHz), a difference of 15% in frequency (for cone angles of 15 degrees the spreadsheet is 1 to 2% different from the exact solution)

It does resonate, and it resonates well:

theoretical Q = 94,254
using a resistivity = 1.678*10^(-8)(*copper*) (Q will go down with increasing resitivity materials and geometrical imperfections)

although this is not much more than the Q calculated for the 30 degrees cavity, so it looks like there are diminishing returns after 30 degrees

I attach below the contour plots for

1) the magnetic field in the spherical radial direction
2) the electric field in the azimuthal circumferential direction

Note how distorted is the magnetic field in the spherical radial direction

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/13/2015 06:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415900#msg1415900">Quote from: flux_capacitor on 08/13/2015 05:17 PM</a>

Although SketchUp is not good at all with circles (it draws them as a series of segments) I updated the number of segments per circle from 24 to 240 in order to improve precision.

I don't know if you need the 2D plan or the 3D modeled object, so I created both versions and exported them in STL format. You can find them zipped below.

Thanks for explaining how you got to that "apparent random" angle...It makes sense now.


STL files are the preferred choice for 3dprinting... ;)

It doesn't really matter because even if you model it with a nurbs modeler software package (smooth and continuous surfaces), in the end, an STL file is a format that only understands 3d points, so all the surfaces are automatically converted to polygons....hence always be an approximation of the real surface.
it is all a matter of conversion resolution then...

what would be the best placement for the waveguide entrance then?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 06:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415917#msg1415917">Quote from: Rodal on 08/13/2015 06:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415900#msg1415900">Quote from: flux_capacitor on 08/13/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415761#msg1415761">Quote from: ElizabethGreene on 08/13/2015 01:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

I might be able to model it.  Can you export an STL of the part?

Although SketchUp is not good at all with circles (it draws them as a series of segments) I updated the number of segments per circle from 24 to 240 in order to improve precision.

I don't know if you need the 2D plan or the 3D modeled object, so I created both versions and exported them in STL format. You can find them zipped below.

This is a very interesting shape to test the outer limits of the theories and methods involved.
Due to the extreme spherical conical shape of this cavity, the limitations of the spreadsheet approach (that in a kludgy way intends to model a sherical cone as a large series of cylinders) is more crudely exposed:

the natural frequency of mode TE013 is 2.132 GHz (instead of 2.45 GHz), a difference of 15% in frequency (for cone angles of 15 degrees the spreadsheet is 1 to 2% different from the exact solution)

It does resonate, and it resonates well:

theoretical Q = 94,254
using a resistivity = 1.678*10^(-8)(*copper*) (Q will go down with increasing resitivity materials and geometrical imperfections)

although this is not much more than the Q calculated for the 30 degrees cavity, so it looks like there are diminishing returns after 30 degrees

I attach below the contour plots for

1) the magnetic field in the spherical radial direction
2) the electric field in the azimuthal circumferential direction

Note how distorted is the magnetic field in the spherical radial direction

And these are the 3D plots of

1) the magnetic field in the spherical radial direction
2) the electric field in the azimuthal circumferential direction

The longitudinal magnetic field is the important field: it makes it look like a manta ray spaceship

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/13/2015 06:52 PM

Quote from: Rodal
theoretical Q = 94,254
using a resistivity = 1.678*10^(-8)(*copper*) (Q will go down with increasing resitivity materials and geometrical imperfections)

Hello sir.
I'm just lurking here. Appreciation for all the work you sir and all you guys do for emdive community.

What if the the copper cavity is cooled down with liquid Nitrogen?
How does it affect the Q-factor in real?
Could the inner portion of the cavity  be lined with YBCO thin film and N2 cooled? Does YBCO film do the job at 2.3G or 23G  freq?

Best, Peter

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 07:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415931#msg1415931">Quote from: Mr. Peter on 08/13/2015 06:52 PM</a>
Quote from: Rodal
theoretical Q = 94,254
using a resistivity = 1.678*10^(-8)(*copper*) (Q will go down with increasing resitivity materials and geometrical imperfections)

Hello sir.
I'm just lurking here. Appreciation for all the work you sir and all you guys do for emdive community.

What if the the copper cavity is cooled down with liquid Nitrogen?
How does it affect the Q-factor in real?
Could the inner portion of the cavity  be lined with YBCO thin film and N2 cooled? Does YBCO film do the job at 2.3G or 23G  freq?

Best, Peter
Welcome to the forum !

Concerning operation of the cavity in the superconducting range, in my humble opinion that is way too complicated to give a thoughtful answer without doing the pertinent analysis, which I haven't done.

Shawyer claims to have been working on superconducting designs for years, but the very limited financial situation of his company reported in a number of posts by WallofWolfStreet in this forum (reported by WWS to be deeply in debt to hundreds of thousand of pounds, not a single employee, etc.) and the lack of experimental measurements (his latest paper in Acta Astronautica dealt mainly with futurustic designs) does not show progress that can be independently assessed.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=875941;image)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 07:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415920#msg1415920">Quote from: Flyby on 08/13/2015 06:13 PM</a>
...
what would be the best placement for the waveguide entrance then?
For the 30 degree superconducting cavity Shawyer is entering asymmetrically from the lateral conical surface:

see above image

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/13/2015 07:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415931#msg1415931">Quote from: Mr. Peter on 08/13/2015 06:52 PM</a>
What if the the copper cavity is cooled down with liquid Nitrogen?
How does it affect the Q-factor in real?

I wonder this exactly since the beginning. After proving this technology is genuine (we're not sure for now) I think we could get high thrust from a cooled frustum, not necessarily superconducting, but just copper cooled with liquid nitrogen. I don't know if the Q would increase (?) but the power could certainly ramp up.

TT's spreadsheet, from Shawyer's advice and using Shawyer's thrust formulae, predict above 1.2 N of force for 2 kW of input power by a design similar to the one I've posted. Yang already used 2.5 kW on a non-superconducting, non-cooled copper frustum in ambient air. So with liquid nitrogen we could go way beyond that!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/13/2015 08:01 PM
Mr. Rodal, thank you for explanation.

Do you think that cooling copper/silver  frustum with N2 might increase the Q-factor? I guess, in that case, the resistivity of copper might be reduced by a factor of 8, but I don't know, 2.4 Gig or even 24Gig is quite high and emdrive cavity is not a standard one.
So what do you thing about N2 cooling in order to gain the Q?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/13/2015 08:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415904#msg1415904">Quote from: Mulletron on 08/13/2015 05:26 PM</a>
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072

Cool! The first section is equivalent to the PV Model of gravity, which I have been attempting to correlate to the waveguide physics. This paper appears to do exactly that!
Thank you! Good find!
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/13/2015 08:20 PM

Seems the UK gov's panel of highly qualified technical experts and academic experts agree Shawyer's Experimental and Demonstrator EMDrives work as claimed.

http://www.publications.parliament.uk/pa/cm200607/cmhansrd/cm061205/text/61205w0031.htm Scroll to almost the bottom.

Quote
Electromagnetic Relativity Drive

Alan Duncan: To ask the Secretary of State for Trade and Industry how much his Department has provided to the electromagnetic relativity drive design proposed by Roger Shawyer; and from what budget funding has been drawn. [103254]

Margaret Hodge [holding answer 27 November 2006]: Awards have been made to Satellite Propulsion Research Ltd from the DTI’s Small Firms and Enterprise budget.

July 2001—£43,809 paid.

A feasibility study into the application of innovative microwave thruster technology for satellite propulsion. The study involved development of an experimental thruster followed by independent tests and evaluation

August 2003—£81,291 total grant awarded, £68,399 paid to date.

A follow-on from the above project, to design and develop a demonstration model engine. To be tested on a dynamic test rig, to demonstrate continuous thrust and the conversion of thrust into kinetic energy.

Both grants were awarded against the criteria of the DTI’s Smart scheme that was designed to help fund pioneering and risky R and D projects in small and medium enterprises.

Highly qualified technical experts and academics carried out an assessment on behalf of the Department.

Bolding added.

1st & 2nd funding was for Shawyer's Experimental EMDrive:
http://emdrive.com/feasibilitystudy.html

3rd & 4th funding, not mentioned, was awarded for the Demonstrator EMDrive and rotary test rig:
http://emdrive.com/demonstratorengine.html
http://emdrive.com/dynamictests.html (longer video is on the home page)

Seems both EMDrives were independently tested and passed a UK gov review panel as the report shows.

Really like those statements:

1) The study involved development of an experimental thruster followed by independent tests and evaluation

2) Highly qualified technical experts and academics carried out an assessment on behalf of the Department

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: venir on 08/13/2015 08:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415951#msg1415951">Quote from: TheTraveller on 08/13/2015 08:20 PM</a>
Seems the UK gov's panel of highly qualified technical experts and academic experts agree Shawyer's Experimental and Demonstrator EMDrives work as claimed.

Long time lurker here, but to me this statement is not what the link you quote states at all. It states only that technical and academic experts carried out an assessment of the claims and were involved with the tests. At no point does it state what the result of that review was.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/13/2015 08:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415958#msg1415958">Quote from: venir on 08/13/2015 08:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415951#msg1415951">Quote from: TheTraveller on 08/13/2015 08:20 PM</a>
Seems the UK gov's panel of highly qualified technical experts and academic experts agree Shawyer's Experimental and Demonstrator EMDrives work as claimed.

Long time lurker here, but to me this statement is not what the link you quote states at all. It states only that technical and academic experts carried out an assessment of the claims and were involved with the tests. At no point does it state what the result of that review was.

The results was SPR got the funding from the UK gov to both build the Experimental EMDrive and the later much more complex Demonstrator EMDrive and the rotary test rig.

More data here attached. Pages 10 - 14.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/13/2015 08:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415944#msg1415944">Quote from: flux_capacitor on 08/13/2015 07:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415931#msg1415931">Quote from: Mr. Peter on 08/13/2015 06:52 PM</a>
What if the the copper cavity is cooled down with liquid Nitrogen?
How does it affect the Q-factor in real?

I wonder this exactly since the beginning. After proving this technology is genuine (we're not sure for now) I think we could get high thrust from a cooled frustum, not necessarily superconducting, but just copper cooled with liquid nitrogen. I don't know if the Q would increase (?) but the power could certainly ramp up.

TT's spreadsheet, from Shawyer's advice and using Shawyer's thrust formulae, predict above 1.2 N of force for 2 kW of input power by a design similar to the one I've posted. Yang already used 2.5 kW on a non-superconducting, non-cooled copper frustum in ambient air. So with liquid nitrogen we could go way beyond that!

Hello mr. flux_capacitor!

Yes, it's definitely worth to give it a go.
Btw, as far as I can tell, you can get YBCO thin film for about  $254, 15 pieces, 1cm2 each.
I guess those films are flexible to some degree.
The Rs  is < 1 m Ohm  @ 10 GHz, 77K, 0T, but I'm not sure if its fine at 24Gig.
If so, the superconducting babyEmdrive  with its tiny cavity can be made.
Not cheap, but still, not arm and leg.
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: mittelhauser on 08/13/2015 11:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415961#msg1415961">Quote from: TheTraveller on 08/13/2015 08:40 PM</a>

The results was SPR got the funding from the UK gov to both build the Experimental EMDrive and the later much more complex Demonstrator EMDrive and the rotary test rig.

More data here attached. Pages 10 - 14.

You are aware that the documents you are so happy about are from 7 years ago?!?

One of the biggest concerns about Sawyer's claims are that he hasn't provided reasonable proof in a decade (e.g. he hasn't even done a vacuum test!!!!). 

The fact that they gave him money 7 years ago and nothing recently (as far as we know) is a HUGE indictment against his claims... 

In other words, every time you post that type of thing, it makes me doubt more.

Which (to be clear - yet again) is a shame because I really want to believe.

My only hope now is that Sawyer stumbled upon something by accident and is just a lousy scientist and businessman - and some of the people in this thread (maybe even you TT) will produce some real evidence....

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/13/2015 11:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415944#msg1415944">Quote from: flux_capacitor on 08/13/2015 07:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415931#msg1415931">Quote from: Mr. Peter on 08/13/2015 06:52 PM</a>
What if the the copper cavity is cooled down with liquid Nitrogen?
How does it affect the Q-factor in real?

I wonder this exactly since the beginning. After proving this technology is genuine (we're not sure for now) I think we could get high thrust from a cooled frustum, not necessarily superconducting, but just copper cooled with liquid nitrogen. I don't know if the Q would increase (?) but the power could certainly ramp up.

As I understand it Q is proportional to power stored/power dissipated.  A big part of the Power dissipated on the bottom of the fraction is from electrical resistance of the resonator walls.  The increase in Q in superconducting cavities is because the resistance of the superconductor goes to zero, making the bottom of the fraction tiny.

Pure Copper is not a superconductor at liquid nitrogen temperatures.  Its resistance decreases as it cools, but not by a huge amount.  The internet  [1] says its temperature coefficient is 3.9x10-3/1 degree C.  So the 220 degree swing from a lab to liquid nitrogen temperatures only cuts the resistance by about half.  I have to caveat this that I am assuming the temperature curve is linear.  That assumption should be verified.  If that assumption is right and if the majority of the losses in your cavity are from electrical resistance then you could theoretically double your Q.

Minuses:
Dissimilar metals shrink at different rates, flimsily soldered bits might break.
Adds a whole new degree of complexity to eliminating measurement error:
- Reduction in mass as coolant boils off
- Vibration of boiling liquid
- Gas jetting from boiling liquid

Plusses:
Will also cool the magnetron, allowing higher duty cycle.
Q increases by some factor.
Is fun to play with and makes great ice cream.

[1] http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html

P.s. I did a quick pass at simulating the double bubble 3d half-sphere resonator from the .STL file.  Initial results indicate many (>9) eigenfrequencies within a magnetron's tunable range around 2.45e9.  I can't guess at modes, damping, or Q until I get the mesh right.  No Eta.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Notsosureofit on 08/13/2015 11:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415904#msg1415904">Quote from: Mulletron on 08/13/2015 05:26 PM</a>
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072

Yes, that's exactly (same equations) how I'm trying to work out the entropy.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/13/2015 11:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415958#msg1415958">Quote from: venir on 08/13/2015 08:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415951#msg1415951">Quote from: TheTraveller on 08/13/2015 08:20 PM</a>
Seems the UK gov's panel of highly qualified technical experts and academic experts agree Shawyer's Experimental and Demonstrator EMDrives work as claimed.

Long time lurker here, but to me this statement is not what the link you quote states at all. It states only that technical and academic experts carried out an assessment of the claims and were involved with the tests. At no point does it state what the result of that review was.
Good post. One of the things I will try and explain on the radio show tonight is the amount of quality information out there is small and should not be taken at face value. More test data is needed, there is no disputing this. For those qualified to build and test, its imperative we collect as much info as possible. Spent decades in Marketing...I know how to "wordsmith" and always avoided it, for it might fool some of the people some of the time, but in the long run makes a person, business or institution look foolish.

I will also try to mention that no one person, institution or business has earned the right to say they have the exact solution and correct theory. While some may try, they have not earned broad scientific support. Its way too early for that IMO.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/13/2015 11:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416005#msg1416005">Quote from: ElizabethGreene on 08/13/2015 11:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415944#msg1415944">Quote from: flux_capacitor on 08/13/2015 07:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415931#msg1415931">Quote from: Mr. Peter on 08/13/2015 06:52 PM</a>
What if the the copper cavity is cooled down with liquid Nitrogen?
How does it affect the Q-factor in real?

I wonder this exactly since the beginning. After proving this technology is genuine (we're not sure for now) I think we could get high thrust from a cooled frustum, not necessarily superconducting, but just copper cooled with liquid nitrogen. I don't know if the Q would increase (?) but the power could certainly ramp up.

As I understand it Q is proportional to power stored/power dissipated.  A big part of the Power dissipated on the bottom of the fraction is from electrical resistance of the resonator walls.  The increase in Q in superconducting cavities is because the resistance of the superconductor goes to zero, making the bottom of the fraction tiny.

Pure Copper is not a superconductor at liquid nitrogen temperatures.  Its resistance decreases as it cools, but not by a huge amount.  The internet  [1] says its temperature coefficient is 3.9x10-3/1 degree C.  So the 220 degree swing from a lab to liquid nitrogen temperatures only cuts the resistance by about half.  I have to caveat this that I am assuming the temperature curve is linear.  That assumption should be verified.  If that assumption is right and if the majority of the losses in your cavity are from electrical resistance then you could theoretically double your Q.
...

Actually it is worse than that.  The dependence of Q on resistivity is due to the skin depth, which goes like the square root of resistivity.  So the Q quality factor depends on the square root of resisitivity.

This means that if you cut the resistivity by a factor of 2, your Q will not double, actually it will increase by only Sqrt[1/(1/2)] = Sqrt[2] = 1.41, only 41% increase in Q from cutting resistivity by a factor of 2.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/14/2015 12:30 AM
Want to know a little more about me? Tough, this is all you will find out ;)

http://othersideofmidnight.com/thu-aug-13-dave-distler/
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/14/2015 01:01 AM
Oh No - Hoaxland  :(
Good luck with that.

I trust you're well aware of the kind of stuff that man has tried to foist on people over these many years.
http://www.badastronomy.com/bad/misc/hoagland/
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/14/2015 01:37 AM
I might be mistaken, but from what that calculator says the swing from 20C down to -195.79C cut the copper resistance by a factor of 6.
As you mentioned before, assuming the temperature curve is linear as shown in the graph below.
The graph also indicates the resistivity of Cu at 77K  ramps down to that region.
So, the Q factor can be doubled. Actually can be multiplied by 2.45, which is huge.

f1big.gif

(Always attach large images and correctly quote who you're speaking to - Moderator).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/14/2015 02:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416030#msg1416030">Quote from: deltaMass on 08/14/2015 01:01 AM</a>
Oh No - Hoaxland  :(
Good luck with that.

I trust you're well aware of the kind of stuff that man has tried to foist on people over these many years.
http://www.badastronomy.com/bad/misc/hoagland/
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 02:33 AM
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/14/2015 04:16 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416033#msg1416033">Quote from: Mr. Peter on 08/14/2015 01:37 AM</a>

Are  you sure?
I might be mistaken, but from what that calculator says the swing from 20C down to -195.79C cut the copper resistance by a factor of 6.
As you mentioned before, assuming the temperature curve is linear as shown in the graph below.
The graph also indicates the resistivity of Cu at 77K  ramps down to that region.
So, the Q factor can be doubled. Actually can be multiplied by 2.45, which is huge.

No, I'm not sure at all and I defer.  I was lazy and used the hyperphysics calculator.  Only now do I notice that it contradicts itself.  It says that 250 ohms at 20 C is 40.3ohms at -195C, but 40.3 ohms at -195C is 74ohms at 20C.  It does the same weird bit using 63 and 278K as well.  Broken?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 05:42 AM
Dr. Rodal,

I generated and uploaded a z-30 slice to 64 cycle Shell-2D-loop-ant, z-30-csvs and z-30-pngs.  Your current link should work so tell me if it doesn't.

I want to thank Imbfan for all of the hard work of automating the generation of these files. I don't think it could have been done manually. Thank you Imbfan.

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/14/2015 06:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416053#msg1416053">Quote from: ElizabethGreene on 08/14/2015 04:16 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416033#msg1416033">Quote from: Mr. Peter on 08/14/2015 01:37 AM</a>
Quote from: ElizabethGreene
...So the 220 degree swing from a lab to liquid nitrogen temperatures only cuts the resistance by about half.  I have to caveat this that I am assuming the temperature curve is linear.  That assumption should be verified.  If that assumption is right and if the majority of the losses in your cavity are from electrical resistance then you could theoretically double your Q.

Are  you sure?
I might be mistaken, but from what that calculator says the swing from 20C down to -195.79C cut the copper resistance by a factor of 6.
As you mentioned before, assuming the temperature curve is linear as shown in the graph below.
The graph also indicates the resistivity of Cu at 77K  ramps down to that region.
So, the Q factor can be doubled. Actually can be multiplied by 2.45, which is huge.

No, I'm not sure at all and I defer.  I was lazy and used the hyperphysics calculator.  Only now do I notice that it contradicts itself.  It says that 250 ohms at 20 C is 40.3ohms at -195C, but 40.3 ohms at -195C is 74ohms at 20C.  It does the same weird bit using 63 and 278K as well.  Broken?

No, it's not broken.
The formula is:
Δρ = α * ΔTCρ0

Where:
Δρ : Change of the resistivity
α : Temperature coefficient of resistance at initial temp
ΔT : Change of temperature
ρ0 : Original resistivity

So if you want to calc change of the resistivity of copper from initial -195C up to 20C, you have to use α=2.27*10-2 [K-1] or there about.
Temperature coefficient of resistance must be  in relation to temperature. So the reference is α= .00386 for copper at 20C.

Anyway, that calc is not good at all, because the resistivity at very low temp is not linear.
At 75K the electrical resistivity of the very pure copper is 0.213*10-8 Ohm m
At 4K it is 0.002*10-8 Ohm m respectively.
So, theoretically, for liquid nitrogen  the resistivity is cut by a factor of 7.89 which gives Q*2.8, and for liquid helium is cut 840 times, which makes the Q of such cavity approx. 29 times higher.
Under ideal conditions.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/14/2015 08:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415873#msg1415873">Quote from: SeeShells on 08/13/2015 03:13 PM</a>

I theorise that the same is happening within the frustum with the traveling waves. We build up a DC magnetic component in the walls from the harmonic mode and when the mode collapses (they all have in every simulation) to form another mode. That switch decaying produces evanescent waves that push into the copper ~5um imparting momentum and force on the still decaying magnetic component left from the last mode.

Shell

Another explanation would be perhaps with longitudinal ampere force [EDIT]If such a thing really exist (see below and try to take a look at the preview not only the abstract, it is striking, kind of frustum shape  ;) ):
http://rd.springer.com/article/10.1140%2Fepjp%2Fi2014-14034-2


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Warren Platts on 08/14/2015 09:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416040#msg1416040">Quote from: rfmwguy on 08/14/2015 02:20 AM</a>
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Hoagland! Boy you walked into that one!  ;) But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! ;D

Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.

Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.

What do you guys think?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 09:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/14/2015 10:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416091#msg1416091">Quote from: Warren Platts on 08/14/2015 09:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416040#msg1416040">Quote from: rfmwguy on 08/14/2015 02:20 AM</a>
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Hoagland! Boy you walked into that one!  ;) But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! ;D

Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.

Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.

What do you guys think?
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar system  8).

I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 11:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)

Please take a look at my messages:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415788#msg1415788

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415830#msg1415830

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415838#msg1415838

I had previously calculated and posted in the messages the fields at the big base from the csv files

The Meep views are still very  wrong please compare them with the ones from the csv files.

Please check your range values.

The range values that you had previously posted were wrong.  Since the contour plots still look wrong, the first thing to do is to check your range values.  What are the range values used for these latest post of views ?

HXz at the Big Base has the highest values in the csv files, yet it appears white and without contours in the Meep images.  There is something very wrong with that.

HYz at the Big Base has the high values in the csv files, close to the values of HXz.   In the Meep view images, HYz at the Big Base looks like what HXz is supposed to look like.    There is something very wrong with that.


It looks like there are big problems in the Meep view files:

* Not showing contours for fields that have high values
* Showing fields with the contours of another field

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 11:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

Take a look at my message:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416148#msg1416148

There are still many problems with these Meep views.  Many of them are wrong.  Fields with high range are shown as white, with no contours.

Other fields are mislabeled, having the contours of another field.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/14/2015 12:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416086#msg1416086">Quote from: OttO on 08/14/2015 08:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415873#msg1415873">Quote from: SeeShells on 08/13/2015 03:13 PM</a>

I theorise that the same is happening within the frustum with the traveling waves. We build up a DC magnetic component in the walls from the harmonic mode and when the mode collapses (they all have in every simulation) to form another mode. That switch decaying produces evanescent waves that push into the copper ~5um imparting momentum and force on the still decaying magnetic component left from the last mode.

Shell

Another explanation would be perhaps with longitudinal ampere force [EDIT]If such a thing really exist (see below and try to take a look at the preview not only the abstract, it is striking, kind of frustum shape  ;) ):
http://rd.springer.com/article/10.1140%2Fepjp%2Fi2014-14034-2
I read this paper by Lars Johansson for his Masters of Science at the Lund Institute in Sweden a couple months ago and stuck it in the back of my mind maybe to be used later. You see I remember years and years ago in school seeing the submarine effect of the pointed copper wire in a mercury trough. We were asked to speculate why it moved. I remember writing a little paper on the resistivity of copper being less than the mercury and considering electrons always took the path of less resistance you would see this effect. The electrons flowing along the walls of the sub submerged in the  mercury would take the path of the copper because of the lower resistance and flow faster in the copper sub inducing a magnetic field in the copper that would act with the currents flowing in the mercury pushing it forward. I got a C on the paper. Not my finest hour, but I was learning, oh geez I still am learning.
 
Lars Johansson's paper is done well as it give a nice background of these forces.

http://dflund.se/~snorkelf/LongitudinalMSc.pdf


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/14/2015 12:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416091#msg1416091">Quote from: Warren Platts on 08/14/2015 09:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416040#msg1416040">Quote from: rfmwguy on 08/14/2015 02:20 AM</a>
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Hoagland! Boy you walked into that one!  ;) But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! ;D

Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.

Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.

What do you guys think?

My cat decided I needed to wake up and listen at 2am by stepping in my eye. I got up and realized it was 2am.  Jumped on the computer to listen. I missed an hour of it but I think it was done very well and rfmwguy you were good.

All in all it was a nice primer and intro to the EM Drive. Nice Job.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/14/2015 12:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

Yes! Great observation. This is another reason I want to excite in the TE012 mode! We've got something like 5 modes through that frequency spread around 2.45GHz... TE312, TE212, TE411, TE311, TE012. Hard to read the chart unless you sharpen the image.

This is the one difference between a circular waveguide and a conical frustum is the excited modes coupling effects causing mode switching and the mode shifting and decaying into the small end (seen the reverse also happen but because it was at the start of some of the meep multicolor flashing Tie-dyed runs a couple months ago they could be in question).

Shell
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 01:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416162#msg1416162">Quote from: SeeShells on 08/14/2015 12:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

Yes! Great observation. This is another reason I want to excite in the TE012 mode! We've got something like 5 modes through that frequency spread around 2.45GHz... TE312, TE212, TE411, TE311, TE012. Hard to read the chart unless you sharpen the image.

This is the one difference between a circular waveguide and a conical frustum is the excited modes coupling effects causing mode switching and the mode shifting and decaying into the small end (seen the reverse also happen but because it was at the start of some of the meep multicolor flashing Tie-dyed runs a couple months ago they could be in question).

Shell
TE 114 is also nearby. Mode superposition/competition(/degenerative mode shape) could lead to interesting effects.
The later interpretation don't will be easier with such complex EM messy mix.
 
All here lurking for your experimental data  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 01:10 PM
Here are the last 14 time step images for the Poynting vector field distribution through the trapezium plane with normal y of the Yang/Shell 6 degree cone angle truncated cone, excited with 2 parallel dipole antennas located near the Small Base.

There is a strong Poynting vector oriented from the big base (at the bottom of the images) to the small base (at the top of the images).
__________________________________________________________________
__________________________________________________________________
Meep data (reproduced from aero's file)
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart.  Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry

(set! fsi 2.45E+009 )                           ; Drive frequency, in SI units, Hz.
(set! bigdia 0.201)                            ; ID - In meters   [CORRECTED from original erroneous file]
(set! bigrad (/ bigdia 2))                   
(set! smalldia 0.1492)                         ; ID - meters   [CORRECTED from original erroneous file]
(set! smallrad (/ smalldia 2))
(set! high 0.24)                    &nbspnbsp;          ; Inner length, meters   [CORRECTED from original erroneous file]

Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
    every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run time set to 26.104377295238095 meep time          set  [CORRECTED from original erroneous file]
run 0 finished at t = 26.106 (13053 timesteps)    [CORRECTED from original erroneous file]
 Resolution = 250
230x196x196x14 is .h5 files dimensions.
  End cuts are at:  Big end -- .h5 row 15         Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/14/2015 01:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416167#msg1416167">Quote from: X_RaY on 08/14/2015 01:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416162#msg1416162">Quote from: SeeShells on 08/14/2015 12:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

Yes! Great observation. This is another reason I want to excite in the TE012 mode! We've got something like 5 modes through that frequency spread around 2.45GHz... TE312, TE212, TE411, TE311, TE012. Hard to read the chart unless you sharpen the image.

This is the one difference between a circular waveguide and a conical frustum is the excited modes coupling effects causing mode switching and the mode shifting and decaying into the small end (seen the reverse also happen but because it was at the start of some of the meep multicolor flashing Tie-dyed runs a couple months ago they could be in question).

Shell
TE 114 is also nearby. Mode superposition/competition could lead to interesting effects.
The later interpretation don't will be easier with such complex EM messy mix.
 
All here lurking for your experimental data  :)
I still need to build a couple of stands yet, the materials that were going to be picked up yesterday by a friend with a truck didn't make it. He was worried that the heavy rains we had would ruin the melamine sheets, he was right. Getting them today and will start putting together the stands for the graph-stand and the digital scales. Still waiting for some hardware to get here from China... It has to be on a slow boat.

I'm pushing as hard as I can as I want it too!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/14/2015 01:26 PM
Nice Poynting show to small end.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 01:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416170#msg1416170">Quote from: Rodal on 08/14/2015 01:10 PM</a>
Here are the last 14 time step images for the Poynting vector field distribution through the trapezium plane with normal y of the Yang/Shell 6 degree cone angle truncated cone, excited with a 2 parallel dipole antennas near the Small Base.

There is a strong Poynting vector oriented from the big base (at the bottom of the images) to the small base (at the top of the images).
__________________________________________________________________
Meep data
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart.  Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry

(set! fsi 2.45E+009 )                           ; Drive frequency, in SI units, Hz.
(set! bigdia 11.01)                             ; ID - inches
(set! smalldia 6.25)                            ; ID - inches
(set! high 10.2)                                ; length - inches

Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
    every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run 0 finished at t = 13.054 (6527 timesteps) - Resolution = 250
230x196x196x14 is .h5 files dimensions.
  End cuts are at:  Big end -- .h5 row 15         Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015
Interesting! Looks like strong vector component always into the direction of the small diameter..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/14/2015 01:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416141#msg1416141">Quote from: deltaMass on 08/14/2015 10:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416091#msg1416091">Quote from: Warren Platts on 08/14/2015 09:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416040#msg1416040">Quote from: rfmwguy on 08/14/2015 02:20 AM</a>
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Hoagland! Boy you walked into that one!  ;) But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! ;D

Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.

Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.

What do you guys think?
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar system  8).

I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.
Thanks DM, I immediately thought of you when he mentioned how skeptics and believers got along so well here. I tried to say that it was a productive thing to have that occur...with civility. Yes,were are some things he talked about before I came on that would question, but its show biz and gets people wondering...

All in all, it was as expected...fun. Actually the 2 hours seemed to fly by. I knew this was the first radio chat about the emdrive, so I tried to keep it as general as I could. Thanks for the comments and for staying up late  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: teitur on 08/14/2015 01:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416179#msg1416179">Quote from: rfmwguy on 08/14/2015 01:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416141#msg1416141">Quote from: deltaMass on 08/14/2015 10:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416091#msg1416091">Quote from: Warren Platts on 08/14/2015 09:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416040#msg1416040">Quote from: rfmwguy on 08/14/2015 02:20 AM</a>
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Hoagland! Boy you walked into that one!  ;) But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! ;D

Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.

Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.

What do you guys think?
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar system  8).

I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.
Thanks DM, I immediately thought of you when he mentioned how skeptics and believers got along so well here. I tried to say that it was a productive thing to have that occur...with civility. Yes,were are some things he talked about before I came on that would question, but its show biz and gets people wondering...

All in all, it was as expected...fun. Actually the 2 hours seemed to fly by. I knew this was the first radio chat about the emdrive, so I tried to keep it as general as I could. Thanks for the comments and for staying up late  8)

It would be very nice if it was possible to download a podcast or get a link so we who couldn't listen live also could hear it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/14/2015 02:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416060#msg1416060">Quote from: aero on 08/14/2015 05:42 AM</a>
Dr. Rodal,

I generated and uploaded a z-30 slice to 64 cycle Shell-2D-loop-ant, z-30-csvs and z-30-pngs.  Your current link should work so tell me if it doesn't.

I want to thank Imbfan for all of the hard work of automating the generation of these files. I don't think it could have been done manually. Thank you Imbfan.

aero

You're very welcome.  I'm glad I could help!  I'll post up the modified python file for others once I make a few more tweaks.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Warren Platts on 08/14/2015 02:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416182#msg1416182">Quote from: teitur on 08/14/2015 01:45 PM</a>
It would be very nice if it was possible to download a podcast or get a link so we who couldn't listen live also could hear it.

THey MIGHT replay it later today, before the regular programming restarts at 4PM EDT; otherwise you have gto pay $5/month to have unlimited podcast access.

http://player.streamguys.com/dmr/sgplayer/player.php

ETA: That was funny when Hoagland said he tried to register at NSF and found out he was already pre-banned! ;D

Come on Chris! Give the man a break! Surely the NSF tent is big enough for everybody! I must say I've never heard anyone else on the radio give so much airtime to NSF! Only good things to say too! :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/14/2015 02:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416182#msg1416182">Quote from: teitur on 08/14/2015 01:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416179#msg1416179">Quote from: rfmwguy on 08/14/2015 01:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416141#msg1416141">Quote from: deltaMass on 08/14/2015 10:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416091#msg1416091">Quote from: Warren Platts on 08/14/2015 09:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416040#msg1416040">Quote from: rfmwguy on 08/14/2015 02:20 AM</a>
I'm more concerned abt getting the word out abt serious work, pro and con, on this global project...outside the veil of corporate and government secrecy. Internet collaboration is what makes this different from most efforts. Want to emphasize that to whomever will listen.

Hoagland! Boy you walked into that one!  ;) But actually he was pretty good at helping to describe the em drive. Very interesting show! Hope you decide to go back on Dave! Nice radio voice too! ;D

Have been intrigued by this topic, but was daunted by trying to wade through all 4 threads. The show was an excellent introduction.

Am dismayed by the apparent lack of theory about how or why this thing works, if it does. I'm reminded of the difference between Edison and Tesla. Edison was the tinkerer who didn't really understand what he was doing, and didn't really care as long as the invention worked. Tesla, on the other hand was the theoretician who was able to progress by leaps and bounds on the basis of his (mostly) sound understanding of the theory.

What do you guys think?
I was pleasantly surprised at how concisely and accurately Hoagland could express himself when he wanted to. He'd obviously done a fair bit of research on the topic and had his duckies in a row there. All the more cognitively dissonant, therefore, when he claims he sees artificial structures on practically every body in the solar system  8).

I'm glad Dave made the point that there isn't one theory that explains EmDrive - I believe that to be a fair representation of the situation. As for the convection issue - well, let's just say it might be problematic, but let's wait and see what the data says.
Thanks DM, I immediately thought of you when he mentioned how skeptics and believers got along so well here. I tried to say that it was a productive thing to have that occur...with civility. Yes,were are some things he talked about before I came on that would question, but its show biz and gets people wondering...

All in all, it was as expected...fun. Actually the 2 hours seemed to fly by. I knew this was the first radio chat about the emdrive, so I tried to keep it as general as I could. Thanks for the comments and for staying up late  8)

It would be very nice if it was possible to download a podcast or get a link so we who couldn't listen live also could hear it.
Looks like all shows are digitally archived and can be listened to anytime. Think you have to sign up for access. Not sure the procedure but you might try here: http://darkmatterdigitalnetwork.com/shows/other-side-of-midnight/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/14/2015 02:29 PM

http://math.mit.edu/~stevenj/papers/JohnsonBi02.pdf

The math behind.
 :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416007#msg1416007">Quote from: Notsosureofit on 08/13/2015 11:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415904#msg1415904">Quote from: Mulletron on 08/13/2015 05:26 PM</a>
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072

Yes, that's exactly (same equations) how I'm trying to work out the entropy.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: teitur on 08/14/2015 02:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416200#msg1416200">Quote from: rfmwguy on 08/14/2015 02:22 PM</a>
Looks like all shows are digitally archived and can be listened to anytime. Think you have to sign up for access. Not sure the procedure but you might try here: http://darkmatterdigitalnetwork.com/shows/other-side-of-midnight/

Got it ! Thanks a lot. (Now to find out how to unsubscribe  :) )

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 03:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416170#msg1416170">Quote from: Rodal on 08/14/2015 01:10 PM</a>
Here are the last 14 time step images for the Poynting vector field distribution through the trapezium plane with normal y of the Yang/Shell 6 degree cone angle truncated cone, excited with 2 parallel dipole antennas located near the Small Base.

There is a strong Poynting vector oriented from the big base (at the bottom of the images) to the small base (at the top of the images).
__________________________________________________________________
Meep data (reproduced from aero's file)
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart.  Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry

(set! fsi 2.45E+009 )                           ; Drive frequency, in SI units, Hz.
(set! bigdia 11.01)                             ; ID - inches
(set! smalldia 6.25)                            ; ID - inches
(set! high 10.2)                                ; length - inches

Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
    every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run 0 finished at t = 13.054 (6527 timesteps) - Resolution = 250
230x196x196x14 is .h5 files dimensions.
  End cuts are at:  Big end -- .h5 row 15         Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015

Thanks for posting that information - I see that I didn't edit the dimensions. Those are NSF-1701(I have edited now). The correct cavity dimensions for the Yang-Shell model are:

(set! bigdia 0.201)                            ; ID - In meters
(set! bigrad (/ bigdia 2))                   
(set! smalldia 0.1492)                         ; ID - meters
(set! smallrad (/ smalldia 2))
(set! high 0.24)                               ; Inner length, meters

I try, but there are a lot of fiddly-bits to keep track of.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/14/2015 03:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416203#msg1416203">Quote from: Rodal on 08/14/2015 02:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416202#msg1416202">Quote from: Ricvil on 08/14/2015 02:29 PM</a>
math.mit.edu/~stevenj/papers/JohnsonBi02.pdf

The math behind.
 :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416007#msg1416007">Quote from: Notsosureofit on 08/13/2015 11:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415904#msg1415904">Quote from: Mulletron on 08/13/2015 05:26 PM</a>
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072

Yes, that's exactly (same equations) how I'm trying to work out the entropy.

Wow.  That is a really great paper.  A goldmine. Thanks for posting the link
Boom! We've got a good lead here imho...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 04:08 PM
Dr. Rodal:

Regarding your concern that the view files seem to be incorrect. We must be more specific because it is not a meep problem. The view png files are generated as follows:

- meep, using the supplied control file, propagates the EM fields and writes the specified output to .h5 files. Then meep goes away, never to be heard from again.
- h5totxt, a different stand-alone program, reads the .h5 files by specified slice, extracts the maximum and minimum data range (saving it) and writes the slice data to the .csv files which are uploaded.
- h5topng, yet another stand-alone program, using the maximum and minimum data extracted by h5totxt above, reads the h5 files and writes the view .png files of the specified slice which are uploaded.

If it were a meep problem then the .h5 data would be wrong but the csv and png data would be consistent.
If it were an h5totxt problem the data that you generate independently of the csv files would not agree with the csv data?
If it were an h5topng problem the ... well, I think this is the place to start. But where do we start with that?

The first check that I can imagine is to verify that the maximum and minimum values per slice pulled by h5totxt are in fact the same as exist in the csv data that you use.

Another possibility is that the x and y coordinates are reversed in my meep control file but if so, the png views and the csv data should be consistent so I discount that as a source of this particular problem.

Perhaps you or others have some debug suggestions?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/14/2015 04:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416203#msg1416203">Quote from: Rodal on 08/14/2015 02:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416202#msg1416202">Quote from: Ricvil on 08/14/2015 02:29 PM</a>
math.mit.edu/~stevenj/papers/JohnsonBi02.pdf

The math behind.
 :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416007#msg1416007">Quote from: Notsosureofit on 08/13/2015 11:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415904#msg1415904">Quote from: Mulletron on 08/13/2015 05:26 PM</a>
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072

Yes, that's exactly (same equations) how I'm trying to work out the entropy.

Wow.  That is a really great paper.  A goldmine. Thanks for posting the link
Just started reading... wow. I'm going to have to read more later...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/14/2015 04:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416202#msg1416202">Quote from: Ricvil on 08/14/2015 02:29 PM</a>
http://math.mit.edu/~stevenj/papers/JohnsonBi02.pdf

The math behind.
 :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416007#msg1416007">Quote from: Notsosureofit on 08/13/2015 11:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415904#msg1415904">Quote from: Mulletron on 08/13/2015 05:26 PM</a>
Wow this is like a mishmash of @Notsosureofit and @Mike McCulloch. It even has a tapered waveguide. Very excited to read this closely later.
http://arxiv.org/abs/physics/0606072

Yes, that's exactly (same equations) how I'm trying to work out the entropy.

Can't wait to get off work so I can study this baby! Thanks. :)
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 04:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416223#msg1416223">Quote from: aero on 08/14/2015 04:08 PM</a>
Dr. Rodal:

Regarding your concern that the view files seem to be incorrect. We must be more specific because it is not a meep problem. The view png files are generated as follows:

- meep, using the supplied control file, propagates the EM fields and writes the specified output to .h5 files. Then meep goes away, never to be heard from again.
- h5totxt, a different stand-alone program, reads the .h5 files by specified slice, extracts the maximum and minimum data range (saving it) and writes the slice data to the .csv files which are uploaded.
- h5topng, yet another stand-alone program, using the maximum and minimum data extracted by h5totxt above, reads the h5 files and writes the view .png files of the specified slice which are uploaded.

If it were a meep problem then the .h5 data would be wrong but the csv and png data would be consistent.
If it were an h5totxt problem the data that you generate independently of the csv files would not agree with the csv data?
If it were an h5topng problem the ... well, I think this is the place to start. But where do we start with that?

The first check that I can imagine is to verify that the maximum and minimum values per slice pulled by h5totxt are in fact the same as exist in the csv data that you use.

Another possibility is that the x and y coordinates are reversed in my meep control file but if so, the png views and the csv data should be consistent so I discount that as a source of this particular problem.

Perhaps you or others have some debug suggestions?
aero,
Last time I checked this you had the wrong range, which resulted in clipping the images at only 3% of maximum value.  That's why there was a problem: it had nothing to do with pixel averaging.  It was because the wrong range was used.

The image with a field near zero was being shown with contours and the other fields were clipped at 3% of their maximum value.

In my last message I suggested that you should start by checking your range, and asked what range did you use this time.

What was the range you input this time?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/14/2015 05:39 PM
A new DIYer is going to resume Iulian Berca's work where it was left, with the same frustum dimensions (the latest one with the cylindrical extension) and same kind of powerful 1100W magnetron.

His nickname is SullyEmDrive on Reddit and he made a great web site:
https://sullyemdrive.wordpress.com

Dimensions of SullyEmDrive's frustum:
Db = 279 mm
Ds = 159 mm
L = 228 mm
cylindrical neck = 76 mm

The small end is tunable with an axial screw so the length between ends is adjustable from 228 to 304 mm.

Unlike Iulian who positioned the waveguide as closely as possible to the big end (see Iulian's diagram (EmDrive.jpg)) Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates.

He may found resonance at TE013 and TE213 modes for various lengths. Will be interesting to measure the produced force for the two modes and see if the longer frustum length for TE013 is better (as advised by Shawyer) than TM213 mode.

It would be cool is Sully could come here on NSF to share his build, ideas and test results :) rfmwguy and others already warned him about security so I hope he will stay safe.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 05:40 PM
Dr. Rodal,

What range did I use? I could send you the shell file that shows the ranges used, but since those values suspect, I think your next question would be, "Why?" so we're working on dumping the data that shows what and why. (or why not)

Note -  The only data set that I will address is the latest 64 cycle 2-d loop ant. data set which I uploaded late yesterday. All other data sets were created using manually intensive techniques which can not be investigated. They can be re-generated once we are in agreement on the 64 cycle 2-d loop ant. data set.

If you want, I could upload a completely new data set, 128 cycle 2-d loop ant. data set which I have ran with h5 files complete. I am waiting until we resolve the current questions before generating and uploading those csv and png data sets but if you need a clean data set that uses only the current state of the software I could upload it. That would eliminate any confusion we may mutually have about "What exactly are we looking at?"
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 06:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416253#msg1416253">Quote from: flux_capacitor on 08/14/2015 05:39 PM</a>
A new DIYer is going to resume Iulian Berca's work where it was left, with the same frustum dimensions (the latest one with the cylindrical extension) and same kind of powerful 1100W magnetron.

His nickname is SullyEmDrive on Reddit and he made a great web site:
https://sullyemdrive.wordpress.com

Dimensions of SullyEmDrive's frustum:
Db = 279 mm
Ds = 159 mm
L = 228 mm
cylindrical neck = 76 mm

The small end is tunable with an axial screw so the length between ends is adjustable from 228 to 304 mm.

Unlike Iulian who positioned the waveguide as closely as possible to the big end (see Iulian's diagram (EmDrive.jpg)) Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates.

He may found resonance at TE013 and TE213 modes for various lengths. Will be interesting to measure the produced force for the two modes and see if the longer frustum length for TE013 is better (as advised by Shawyer) than TM213 mode.

It would be cool is Sully could come here on NSF to share his build, ideas and test results :) rfmwguy and others already warned him about security so I hope he will stay safe.

Should be interesting times as we have 2 new builds that are based on the EW copper frustum dimensions with small end constant diameter extensions.

Those small end extensions being used by both builders should alter the spherical waves in the tapered waveguide section into planar waves in the constant diameter extension section, thus giving the benefit of a spherical convex small end plate fitted to a non extended frustum, while using a much simpler to build flat end plate.

Will be interesting to compare the Specific Forces generated versus the magnetron antenna position.

This direct inside the frustum feed may help to overcome the more traditional waveguide feed needing a very low Q to allow the frustum to accept the wide magnetron bandwidth. As the antenna is inside the frustum, well all the magnetron energy is there, so no back reflection. Issue is then to get it to resonate and in a desirable mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 06:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

It cannot be TE311 because TE311 has 6 poles equally spaced around the circumference and I don't see anything with 6 poles around the circumference.

Be careful with ascertaining what mode it is from the hstop images in the Meep file for this run because there are several fields that are mislabeled in these images.

Take a look instead at the raw output csv files which are fine.

Looking at the csv files it is clear that it is a TEm12 mode.

This is one of the few fields that is correctly labeled and correctly ranged in the hstop Meep images, shown in an excellent movie gif you made:

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1056527;image)

Notice the typical profile of TE012 in this movie

A circular cross-section should show a circular field for m=0, this is not the case because

a) cartesian coordinate instead of spherical coordinate fields are shown
b) Most fields are zero at the ends shown: big and small bases, Hz should be zero, the transverse E field should be zero.  So the ends are useless to tell what mode shape it is.
c) the effect of the parallel 2-dipole antenna


I'm pretty sure that the mode shape is TE012 presenting a diameter indentation as an effect from the antenna.

So:

1) The good news is that aero finally succeeded in exciting a TE mode, by using a parallel 2-Dipole antenna

2) It is evident that the parallel 2-Dipole antenna severely affects the mode through the cross section, because the excitation is taking place practically like a line instead of a loop. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed


Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 06:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416253#msg1416253">Quote from: flux_capacitor on 08/14/2015 05:39 PM</a>
...Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates....
From what we are learning from Meep, the best place to place the RF feed is near the big base, not at the middle and not at the small end.   I initially thought it was better to have the antenna near the small end (based on several arguments).  I have changed my mind based on the facts presented by multiple Meep runs.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 06:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

It is not a TE311 because TE311 has 6 poles equally spaced around the circumference and I don't see anything with 6 poles around the circumference.

Be careful with ascertaining what mode it is from the hstop images in the Meep file for this run because there are several fields that are mislabeled in these images.

Take a look instead at the raw output csv files which are fine.

Looking at the csv files it is clear that it is a TEm12 mode.

A circular cross-section should show a circular field for m=0, this is not the case because

a) cartesian coordinate fields are shown
b) the effect of the parallel 2-dipole antenna

I'm pretty sure that the mode shape is TE012 presenting a diameter indentation as an effect from the antenna.

So:

1) The good news is that aero finally succeeded in exciting a TE mode, by using a parallel 2-Dipole antenna

2) It is evident that the parallel 2-Dipole antenna severely affects the mode through the cross section, because the excitation is taking place practically like a line instead of a loop. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.
Thats why i have sad "it looks like" at some pictures, the GIF files i build show TE012.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 06:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
2) It is evident that the parallel 2-Dipole antenna severely affects the mode. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Like this?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 08/14/2015 06:45 PM
Has anybody tried modifying the magnetron E probe, cutting it down to form a current loop ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 06:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416267#msg1416267">Quote from: TheTraveller on 08/14/2015 06:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
2) It is evident that the parallel 2-Dipole antenna severely affects the mode. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Like this?

NASA must have the RF near the big end (correct me if I'm wrong) because they have the dielectric at the small end blocking the ability to put an antenna there.

It appears (correct me if I'm wrong) that NASA has the circular loop near the conical lateral surface.  From the Meep runs I have learned that this produces all kinds of asymmetric waves that decrease the Q.  It would be much better to have the circular loop in the very center  with the axis of axi-symmetry of the cone going through the center of the circular loop antenna instead of being offset. 

I imagine that a bigger loop antenna with its center on the axis of axi-symmetry of the cone would be ideal.

I wonder whether this placement of the NASA loop feed being so asymmetric is one of the reasons that NASA was not able to robustly reproduce TE modes (the only successful TE test they were able to conduct with only 2 watts input power was the mode that produced the most force/InputPower NASA ever reported).  NASA has been running TM212 ever since.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 06:59 PM

From Paul March, private communication.

Quote
Steve:  The current loop antenna in the copper frustum has a 14mm OD and is made from #20 AWG magnet wire soldered to an SMA bulkhead connector.  This assembly is then rotated to maximize the S11 return loss for a given resonant frequency while using an RG-142 SMA-to-SMA coaxial cable run, which is typically 2.0 feet long.  Location is on the frustum sidewall 1.35 inch up from the interior flat surface of the large OD end of the frustum.


Yes, I would expect much different cavity excitation if the antenna were on the central axis of rotation.

I also wonder about how much rotation was needed. Did the antenna end up in a horizontal or vertical plane relative to the big base, or was it some numbers of degrees away from either horizontal or vertical.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 07:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416271#msg1416271">Quote from: Rodal on 08/14/2015 06:45 PM</a>
I imagine that a bigger loop antenna with its center on the axis of axi-symmetry of the cone would be ideal.

Agree and plan to test just such a TE013 mode excitation antenna design. Will have a coax feed from the inside side wall feed point to the point where the circular loop antenna will be installed.

          |                                                            |
         |                                                              |
        |                                                                |
==>|<=====0 <---------Loop---------> 0          |
       |      coax                                                      |               
      |__________________________________ |

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 07:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416266#msg1416266">Quote from: X_RaY on 08/14/2015 06:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416093#msg1416093">Quote from: X_RaY on 08/14/2015 09:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416041#msg1416041">Quote from: aero on 08/14/2015 02:33 AM</a>
Dr. Rodal,

New png files are uploaded for the 64 cycle Shell 2d loop antenna case. I put up the new csv files as well but they "should" be identical to the previous ones. The png files are named slightly differently than previously so I uploaded them into the existing folders. You won't have any difficulty telling the difference visually, but of course your computer will. I have attached one of the new files here just so all can see the effect of changing the scaling range. And note that the pixel grid separation is exactly the same, 1.1 mm while 1/20th of the length of the frustum is about 12 mm.

Still haven't made your x-30 slice that you asked for a few days ago. Will get it up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmVCZlhnNUVtTGRoTTlZSGJiT3ZfSHBvYnNELUc1WlN0Sk15ZDZud3pSWmM&usp=sharing)
For some of the pics there seems to be a weak coupling of TE31 eigenvalue
(I get ~2.39GHz for TE311 and ~2.63GHz for TE312, hope i didn't make a mistake! p=1 and p=2 are very close... Rechecked numbers are welcome).

Most interesting is that the whole run looks like coupling to different modes at different time steps inclusive target mode TE012 (TE31p,TM112?)

It is not a TE311 because TE311 has 6 poles equally spaced around the circumference and I don't see anything with 6 poles around the circumference.

Be careful with ascertaining what mode it is from the hstop images in the Meep file for this run because there are several fields that are mislabeled in these images.

Take a look instead at the raw output csv files which are fine.

Looking at the csv files it is clear that it is a TEm12 mode.

A circular cross-section should show a circular field for m=0, this is not the case because

a) cartesian coordinate fields are shown
b) the effect of the parallel 2-dipole antenna

I'm pretty sure that the mode shape is TE012 presenting a diameter indentation as an effect from the antenna.

So:

1) The good news is that aero finally succeeded in exciting a TE mode, by using a parallel 2-Dipole antenna

2) It is evident that the parallel 2-Dipole antenna severely affects the mode through the cross section, because the excitation is taking place practically like a line instead of a loop. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.
Thats why i have sad "it looks like" at some pictures, the GIF files i build show TE012.
aero's model is very close to a sketch i post some times ago..
Not the same position but based on that principle

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 07:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416274#msg1416274">Quote from: aero on 08/14/2015 06:59 PM</a>
From Paul March, private communication.

Quote
Steve:  The current loop antenna in the copper frustum has a 14mm OD and is made from #20 AWG magnet wire soldered to an SMA bulkhead connector.  This assembly is then rotated to maximize the S11 return loss for a given resonant frequency while using an RG-142 SMA-to-SMA coaxial cable run, which is typically 2.0 feet long.  Location is on the frustum sidewall 1.35 inch up from the interior flat surface of the large OD end of the frustum.


Yes, I would expect much different cavity excitation if the antenna were on the central axis of rotation.

I also wonder about how much rotation was needed. Did the antenna end up in a horizontal or vertical plane relative to the big base, or was it some numbers of degrees away from either horizontal or vertical.

Rotation degree can be seen here

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 07:31 PM
We continue the program started with posts
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1403629#msg1403629
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404000#msg1404000
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404004#msg1404004
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404005#msg1404005
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404006#msg1404006
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404754#msg1404754
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404783#msg1404783
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1406306#msg1406306
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1409278#msg1409278
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1410556#msg1410556
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1411067#msg1411067

showing the stress (force/unitArea) on the big base for the Yang/Shell 6 degree truncated cone, with TE012 at ~2.45GHz with the parallel 2 dipole antenna  located near the small end in the transverse direction.

The stress tensor component is obtained using Wolfram Mathematica (http://www.wolfram.com/mathematica/ ) , post-processed from the transient Finite Difference (using Meep) solution for RF feed ON.
In order to compare the stresses to the previous cases, I have shown all plots to the same numerical scale. 

The stress on the big base (produced by TE012 with the antenna near the small base) is compressive, as in the previous cases.

The "dimple" along the diameter direction is produced by the 2-Dipole parallel antenna, distorting the mode.  Take a smooth volcano made of a compressible foam and indent with a bar going through the center.

Notice that the magnitude of stresses are much higher than those previously shown for TM modes.
__________________________________________________________________
Meep data (reproduced from aero's file)
Yang-Shell model - 64 cycle run
SeeShell's conic frustum model using 2 parallel dipoles, 0.55 wavelength from and parallel to the small end, 0.9 wavelength long and 1 wavelength apart.  Centrally located with middle at axis of asy-symmetry of cone.
z axis = axis of axy-symmetry

(set! fsi 2.45E+009 )                           ; Drive frequency, in SI units, Hz.
(set! bigdia 0.201)                            ; ID - In meters   [CORRECTED from original erroneous file]
(set! bigrad (/ bigdia 2))                   
(set! smalldia 0.1492)                         ; ID - meters   [CORRECTED from original erroneous file]
(set! smallrad (/ smalldia 2))
(set! high 0.24)                               ; Inner length, meters   [CORRECTED from original erroneous file]

Source excitation magnetic component Hz.
Run length - 64 full cycles
Time slices output for each field component:
    every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)
run time set to 26.104377295238095 meep time          set  [CORRECTED from original erroneous file]
run 0 finished at t = 26.106 (13053 timesteps)    [CORRECTED from original erroneous file]
 Resolution = 250
230x196x196x14 is .h5 files dimensions.
  End cuts are at:  Big end -- .h5 row 15         Small end -- .h5 row 214
Note: Resonant frequency calculated by meep is 2.463GHz
NSF handle_aero__ Date of upload. 8/6/2015
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 07:36 PM
Here I show the stress at the small base for TE012 at ~2.45GHz for Yang/Shell geometry at 6 degrees and we find something truly new and unique:

the stress is tensile !!!!: the magnetic field is pulling away from the surface.

This is extremely important to explain the thrust of the EM Drive and Shawyer's "need for background forces or vibrations to produce thrust" but I don't have the time or space to explain why.

The fact that the magnetic field on a surface can result in tensile stresses, while the electric field on a surface only produces compressive stresses was already shown by Greg Egan (but not to this detail).




Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 07:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416279#msg1416279">Quote from: TheTraveller on 08/14/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416274#msg1416274">Quote from: aero on 08/14/2015 06:59 PM</a>
From Paul March, private communication.

Quote
Steve:  The current loop antenna in the copper frustum has a 14mm OD and is made from #20 AWG magnet wire soldered to an SMA bulkhead connector.  This assembly is then rotated to maximize the S11 return loss for a given resonant frequency while using an RG-142 SMA-to-SMA coaxial cable run, which is typically 2.0 feet long.  Location is on the frustum sidewall 1.35 inch up from the interior flat surface of the large OD end of the frustum.


Yes, I would expect much different cavity excitation if the antenna were on the central axis of rotation.

I also wonder about how much rotation was needed. Did the antenna end up in a horizontal or vertical plane relative to the big base, or was it some numbers of degrees away from either horizontal or vertical.

Rotation degree can be seen here

I saw that image, but that is a representation, not a photograph. No way to snap a photo from that angle inside the frustum or is there? I suppose they could have made the adjustments using the S11 return loss then removed the small end, stuck a camera inside and taken the shot.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 07:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416286#msg1416286">Quote from: aero on 08/14/2015 07:44 PM</a>
I saw that image, but that is a representation, not a photograph. No way to snap a photo from that angle inside the frustum or is there? I suppose they could have made the adjustments using the S11 return loss then removed the small end, stuck a camera inside and taken the shot.

There is a small hole in the side wall, near the small end, EWs use for a feedback sense port for their PLL. Easy to insert a fibre optic camera probe to get a few pics inside or remove the small end as you suggest.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/14/2015 07:51 PM
https://en.wikipedia.org/wiki/Allais_effect
This is the (inconclusive) effect to which Hoagland referred in the radio show.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 07:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416293#msg1416293">Quote from: deltaMass on 08/14/2015 07:51 PM</a>
https://en.wikipedia.org/wiki/Allais_effect
This is the (inconclusive) effect to which Hoagland referred in the radio show.

This is interesting:

Quote
Allais’s explanation for another anomaly (the lunisolar periodicity in variations of the azimuth of a pendulum) is that space evinces certain anisotropic characteristics, which he ascribes to motion through an aether which is partially entrained by planetary bodies. He has presented this hypothesis in his 1997 book L’Anisotropie de l’espace. This explanation has not gained significant traction amongst mainstream scientists.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 08:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416294#msg1416294">Quote from: Rodal on 08/14/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416293#msg1416293">Quote from: deltaMass on 08/14/2015 07:51 PM</a>
https://en.wikipedia.org/wiki/Allais_effect
This is the (inconclusive) effect to which Hoagland referred in the radio show.

This is interesting:

Quote
Allais’s explanation for another anomaly (the lunisolar periodicity in variations of the azimuth of a pendulum) is that space evinces certain anisotropic characteristics, which he ascribes to motion through an aether which is partially entrained by planetary bodies. He has presented this hypothesis in his 1997 book L’Anisotropie de l’espace. This explanation has not gained significant traction amongst mainstream scientists.
like to remenber:
https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment

nevertheless interesting link (not available in german wikipedia  >:( this was completely new for me, thanks for that link deltaMass)
https://en.wikipedia.org/wiki/Allais_effect

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/14/2015 08:55 PM
don't know how helpful this is but i do search at arxiv.org for "tapered waveguide" ...

find this for exampe:
http://arxiv.org/pdf/1001.1254v1.pdf

and many many many more...
Only the whole community is able to review all of this  ::)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/14/2015 08:56 PM
Quote

    Source excitation magnetic component Hz.            Yes
    Run length - 64 full cycles                                     Yes
    Time slices output for each field component:
        every 1/10-th cycle from 62.7 cycles to 64 cycles (end of run)    Yes
    run 0 finished at t = 13.054 (6527 timesteps) -         No -
run time set to 26.104377295238095 meep time          set
run 0 finished at t = 26.106 (13053 timesteps)             Yes
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 09:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416309#msg1416309">Quote from: X_RaY on 08/14/2015 08:55 PM</a>
don't know how helpful this is but i do search at arxiv.org for "tapered waveguide" ...

find this for exampe:
http://arxiv.org/pdf/1001.1254v1.pdf

and many many many more...
Only the whole community is able to review all of this  ::)

Thank you.  I had not seen this paper.

This paper is very, very important as it answers a question that has repeatedly been asked in this forum and in Reddit:

what is the best function to use for the taper?

Shawyer used a linear taper (conical) but lacked the resources to explore other geometries (either numerically or by experiment)

Other researchers have not explored other taper geometries either

Musical people usually come with this question as to why don't people use musical horn shapes for the EM Drive.  Invariably their question is answered by saying that the frequencies of the EM drive are much higher than the acoustical frequencies of French Horns, but the question of optimal shape is not answered.

The authors of this paper answer by saying:

Quote
Best tradeoff is obtained with the exponential formulation with a slow variation of the
material parameters

that the best taper is exponential instead of linear (conical).  However they do not use the same formulation of the problem as they don't of course deal with "thrust" (if there is such a thing) and they consider a simultaneous variation of material properties.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/14/2015 09:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416316#msg1416316">Quote from: Rodal on 08/14/2015 09:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416309#msg1416309">Quote from: X_RaY on 08/14/2015 08:55 PM</a>
don't know how helpful this is but i do search at arxiv.org for "tapered waveguide" ...

find this for exampe:
http://arxiv.org/pdf/1001.1254v1.pdf

and many many many more...
Only the whole community is able to review all of this  ::)

Thank you.  I had not seen this paper.

This paper is very, very important as it answers a question that has repeatedly been asked in this forum and in Reddit:

what is the best function to use for the taper?

Shawyer used a linear taper (conical) but lacked the resources to explore other geometries (either numerically or by experiment)

Other researchers have not explored other taper geometries either

Musical people usually come with this question as to why don't people use musical horn shapes for the EM Drive.  Invariably their question is answered by saying that the frequencies of the EM drive are much higher than the acoustical frequencies of French Horns, but the question of optimal shape is not answered.

The authors of this paper answer by saying:

Quote
Best tradeoff is obtained with the exponential formulation with a slow variation of the
material parameters

that the best taper is exponential instead of linear (conical).  However they do not use the same formulation of the problem as they don't of course deal with "thrust" (if there is such a thing) and they consider a simultaneous variation of material properties.
Doc, have a bit of news for you here. Because of the flexibility of the copper mesh, I can "compress" it with a band to form an exponential taper. Not a lot, but some.

Now, if I just knew how much and where ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/14/2015 10:06 PM
Hmm - Adjustapalooza. 6 bands at 4 adjusting screws per band plus 3 screws for impedance matching plus end plate screw. 28 screws and you're set  8)

In fact, compared with the typical complexity of an optical bench for quantum experiments, this is child's play.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 08/14/2015 10:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416320#msg1416320">Quote from: rfmwguy on 08/14/2015 09:43 PM</a>
Doc, have a bit of news for you here. Because of the flexibility of the copper mesh, I can "compress" it with a band to form an exponential taper. Not a lot, but some.

Now, if I just knew how much and where ;)

Assuming all of this is real, it's starting to sound like the optimal design is a convergence of Shawyer's EM drive and the Cannae device. What are the odds?  ;D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Josave on 08/14/2015 10:19 PM
Another geometry is proposed in http://arxiv.org/pdf/math-ph/0408055v1.pdf . Picture is attached.

This spheroid must be moving to create wavelets, that unlike sinusoids, have much more frequency components. Maybe this is a way to allow in McCulloch terms "the number of allowed Unruh waves increases..." in the "...wider side of the cavity".

These are my speculations, but the key in this article is that a moving spheroid geometry can lead to interesting field distributions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/14/2015 10:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416264#msg1416264">Quote from: Rodal on 08/14/2015 06:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416253#msg1416253">Quote from: flux_capacitor on 08/14/2015 05:39 PM</a>
...Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates....
From what we are learning from Meep, the best place to place the RF feed is near the big base, not at the middle and not at the small end.   I initially thought it was better to have the antenna near the small end (based on several arguments).  I have changed my mind based on the facts presented by multiple Meep runs.

Why? Do you believe it is better for resonance, or better for thrust?  It seems counter intuitive because the big end will be reflecting more, not less.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/14/2015 10:51 PM
The configuration space is massive. Take, for example, a tuba mounted on a blender  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 11:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416331#msg1416331">Quote from: WarpTech on 08/14/2015 10:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416264#msg1416264">Quote from: Rodal on 08/14/2015 06:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416253#msg1416253">Quote from: flux_capacitor on 08/14/2015 05:39 PM</a>
...Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates....
From what we are learning from Meep, the best place to place the RF feed is near the big base, not at the middle and not at the small end.   I initially thought it was better to have the antenna near the small end (based on several arguments).  I have changed my mind based on the facts presented by multiple Meep runs.

Why? Do you believe it is better for resonance, or better for thrust?  It seems counter intuitive because the big end will be reflecting more, not less.
Todd

Assuming the antenna is 1/4 guide wavelength away from the end plate, the reflected EM wave is 180 deg out of phase with the radiating antenna. The big end plate becomes a reflector element in a 2 element array. This will cause more of the antenna's radiated energy to be directed at the small end than at the big end as the antenna is now directional.

http://www.ph.surrey.ac.uk/satellites/main/assets/schoolzone/project1/reflectors_directors.htm

Suspect this may also cause an out of phase shadow zone on the big end plate, reducing bounce Force inside the shadow zone due to phase distortion between the radiating antenna and the EM wave propagating from the small end..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/14/2015 11:18 PM
Interesting Reddit post.

micronewton electromagnetic thruster
https://www.reddit.com/r/EmDrive/comments/3h15k6/a_couple_of_interesting_links_not_emdrive_related/
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/14/2015 11:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416337#msg1416337">Quote from: TheTraveller on 08/14/2015 11:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416331#msg1416331">Quote from: WarpTech on 08/14/2015 10:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416264#msg1416264">Quote from: Rodal on 08/14/2015 06:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416253#msg1416253">Quote from: flux_capacitor on 08/14/2015 05:39 PM</a>
...Sully positioned his more near the small end. So at full small-end extension, the waveguide will be roughly in the middle of the two end plates....
From what we are learning from Meep, the best place to place the RF feed is near the big base, not at the middle and not at the small end.   I initially thought it was better to have the antenna near the small end (based on several arguments).  I have changed my mind based on the facts presented by multiple Meep runs.

Why? Do you believe it is better for resonance, or better for thrust?  It seems counter intuitive because the big end will be reflecting more, not less.
Todd

Assuming the antenna is 1/4 guide wavelength away from the end plate, the reflected EM wave is 180 deg out of phase with the radiating antenna. The big end plate becomes a reflector element in a 2 element array. This will cause more of the antenna's radiated energy to be directed at the small end than at the big end as the antenna is now directional.

http://www.ph.surrey.ac.uk/satellites/main/assets/schoolzone/project1/reflectors_directors.htm

Suspect this may also cause an out of phase shadow zone on the big end plate, reducing bounce Force inside the shadow zone due to phase distortion between the radiating antenna and the EM wave propagating from the small end..
Excellent analysis

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/15/2015 04:56 AM
Attached is the update to the python script that generates the csv and png files.  The current iteration runs the h5totxt command and captures the output.  The output is parsed, and the minimum and maximum values for that field and axis are stored.  After all csv files are created, the stored values are consolidated into the fields, E and H, to produce a final min and max value for each field.  These values are then used to generate the png files. The end result is that all E fields will have the same min and max values, as will all the H fields.

The min and max values are collected in each direction specified.  Therefore, if only z slices are output, only the min and max for those slices will be considered, and the min and max may be different if x or y slices are also included in the run.  The upshot is, each set of slices should be re-run to get the full range.  The values are collected over time slices, so the min and max output at t=0 will be the same as at t=13.

Using the -h flag will list all the other flags that can be used.  If no x, y, or z flags are used, nothing will be output.  The special small and big end flags (-s/--z-small-end, -b/--z-big-end) will use the output directories Small-end-z-views and Big-end-z-views for the png files.  The x, y, and z flags put the png in x-views, y-views, z-views.  The special flags -x0, -y0, and -z0 will put them in Center-x-views, etc.  These directories must be pre-created.  The required flag -d/--csv-directory is the directory the csv files will be created in, and must also be pre-created.  Having these directories created if they do not already exist is the next improvement on the list.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/15/2015 05:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416320#msg1416320">Quote from: rfmwguy on 08/14/2015 09:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416316#msg1416316">Quote from: Rodal on 08/14/2015 09:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416309#msg1416309">Quote from: X_RaY on 08/14/2015 08:55 PM</a>
don't know how helpful this is but i do search at arxiv.org for "tapered waveguide" ...

find this for exampe:
http://arxiv.org/pdf/1001.1254v1.pdf

and many many many more...
Only the whole community is able to review all of this  ::)

Thank you.  I had not seen this paper.

This paper is very, very important as it answers a question that has repeatedly been asked in this forum and in Reddit:

what is the best function to use for the taper?

Shawyer used a linear taper (conical) but lacked the resources to explore other geometries (either numerically or by experiment)

Other researchers have not explored other taper geometries either

Musical people usually come with this question as to why don't people use musical horn shapes for the EM Drive.  Invariably their question is answered by saying that the frequencies of the EM drive are much higher than the acoustical frequencies of French Horns, but the question of optimal shape is not answered.

The authors of this paper answer by saying:

Quote
Best tradeoff is obtained with the exponential formulation with a slow variation of the
material parameters

that the best taper is exponential instead of linear (conical).  However they do not use the same formulation of the problem as they don't of course deal with "thrust" (if there is such a thing) and they consider a simultaneous variation of material properties.
Doc, have a bit of news for you here. Because of the flexibility of the copper mesh, I can "compress" it with a band to form an exponential taper. Not a lot, but some.

Now, if I just knew how much and where ;)
Be careful with that, the eigenmodes in your frustum will get a shift to higher frequencies if you compress the side walls to a lower diameter.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/15/2015 05:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415917#msg1415917">Quote from: Rodal on 08/13/2015 06:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415900#msg1415900">Quote from: flux_capacitor on 08/13/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415761#msg1415761">Quote from: ElizabethGreene on 08/13/2015 01:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415723#msg1415723">Quote from: flux_capacitor on 08/12/2015 09:59 PM</a>
I keep thinking about the idea (http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412971#msg1412971) I had a few days ago and pushed it further. I thought about Rodal and WarpTech's advice of increasing cone angle and keeping the apex as near as possible of the small end. I also kept Shawyer's high Df and concentric spherical ends to maintain a high Q, and I've ended up with this wide and shallow resonant design, with incredible large spherical ends, making the frustum almost a half-sphere:

Db = 600 mm
Ds = 150 mm
L = 51.20 mm

r1 =  76.92 mm
r2 = 307.67 mm
r2-r1 = 230.75 mm
θ = 77.18°

Resonance at 2.45 GHz in TE013 mode, Df = 0.96

Would be a challenge to build but nevertheless interesting to test. What could be the Q of such a cavity?

I might be able to model it.  Can you export an STL of the part?

Although SketchUp is not good at all with circles (it draws them as a series of segments) I updated the number of segments per circle from 24 to 240 in order to improve precision.

I don't know if you need the 2D plan or the 3D modeled object, so I created both versions and exported them in STL format. You can find them zipped below.

This is a very interesting shape to test the outer limits of the theories and methods involved.
Due to the extreme spherical conical shape of this cavity, the limitations of the spreadsheet approach (that in a kludgy way intends to model a spherical cone as a large series of cylindrical waveguides) is more crudely exposed:

the natural frequency of mode TE013 is 2.132 GHz (instead of 2.45 GHz), a difference of 15% in frequency (for cone angles of 15 degrees the spreadsheet is 1 to 2% different from the exact solution)

It does resonate, and it resonates well:

theoretical Q = 94,254
using a resistivity = 1.678*10^(-8)(*copper*) (Q will go down with increasing resitivity materials and geometrical imperfections)

although this is not much more than the Q calculated for the 30 degrees cavity, so it looks like there are diminishing returns after 30 degrees

I attach below the contour plots for

1) the magnetic field in the spherical radial direction
2) the electric field in the azimuthal circumferential direction

Note how distorted is the magnetic field in the spherical radial direction

Um doc, didn't the South African science fair experiment show greater thrust by increasing the size of the cavity?  Seems like that would indicate that volume of the cavity and not just Q is a factor.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/15/2015 12:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416390#msg1416390">Quote from: SteveD on 08/15/2015 05:29 AM</a>
...Um doc, didn't the South African science fair experiment show greater thrust by increasing the size of the cavity?  Seems like that would indicate that volume of the cavity and not just Q is a factor.
1) Volume of the cavity was taken into account in the calculations: one cannot calculate the natural frequency and mode shape without knowing the dimensions.  To calculate the quality factor Q one needs to perform an integration of the electromagnetic fields over the whole volume.  Thus the Q is very much related to the volume.

2) Very little is known about the South African experiment.  Important variables were not measured for the South African experiment, for example the Q was not measured or reported.  We don't know whether the cavity was at a higher amplitude resonance by extending the cavity length and hence whether the Q was higher by extending the cavity length, purely due to resonance.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/15/2015 04:21 PM
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281, for a total run time of 0.026 microseconds with the RF feed on.

The net force (shown in green) is the vector addition of the forces on both ends.

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/15/2015 04:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416316#msg1416316">Quote from: Rodal on 08/14/2015 09:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416309#msg1416309">Quote from: X_RaY on 08/14/2015 08:55 PM</a>
don't know how helpful this is but i do search at arxiv.org for "tapered waveguide" ...

find this for exampe:
http://arxiv.org/pdf/1001.1254v1.pdf

and many many many more...
Only the whole community is able to review all of this  ::)

Thank you.  I had not seen this paper.

This paper is very, very important as it answers a question that has repeatedly been asked in this forum and in Reddit:

what is the best function to use for the taper?

Shawyer used a linear taper (conical) but lacked the resources to explore other geometries (either numerically or by experiment)

Other researchers have not explored other taper geometries either

Musical people usually come with this question as to why don't people use musical horn shapes for the EM Drive.  Invariably their question is answered by saying that the frequencies of the EM drive are much higher than the acoustical frequencies of French Horns, but the question of optimal shape is not answered.

The authors of this paper answer by saying:

Quote
Best tradeoff is obtained with the exponential formulation with a slow variation of the
material parameters

that the best taper is exponential instead of linear (conical).  However they do not use the same formulation of the problem as they don't of course deal with "thrust" (if there is such a thing) and they consider a simultaneous variation of material properties.

"Like a trombone" I said...
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/15/2015 04:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/15/2015 05:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Hi Shell.
At the first look the orientation of your rectangular waveguide is not the best to excite TE012 (for the other possible modes i have to think about later this day...).
For this type of waveguide the E field is in b-direction  which is the shorter side of the rectangle.. H is in a-z direction(z means propagation direction in the waveguide). For TE01 i would rotate both antennas 90deg. But of course its your turn. :)
https://en.wikipedia.org/wiki/Waveguide_(electromagnetism)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/15/2015 05:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416459#msg1416459">Quote from: X_RaY on 08/15/2015 05:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Hi Shell.
At the first look the orientation of your rectangular waveguide is not the best to excite TE012 (for the other possible modes i have to think about later this day...).
For this type of waveguide the E field is in b-direction  which is the shorter side of the rectangle.. H is in a-z direction(z means propagation direction in the waveguide). For TE01 i would rotate both antennas 90deg. But of course its your turn. :)

Picture source:wikipedia

It is a hexagon. She made the sides flat to make it easier to attach 2 magnetrons opposite each other, so they will couple and synchronize. Now you're saying she should mount them to the opposing 120-deg corners?  If what you say is correct, then a rectangle or octagon would've been better than a hexagon.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/15/2015 05:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416465#msg1416465">Quote from: WarpTech on 08/15/2015 05:29 PM</a>
It is a hexagon. She made the sides flat to make it easier to attach 2 magnetrons opposite each other, so they will couple and synchronize.

For now SeeShells will use one single magnetron that has 2 outputs, so the waves come in a more symmetric fashion inside.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416465#msg1416465">Quote from: WarpTech on 08/15/2015 05:29 PM</a>
Now you're saying she should mount them to the opposing 120-deg corners?  If what you say is correct, then a rectangle or octagon would've been better than a hexagon.
Todd

I think X_RaY proposed to turn the waveguides 90° but they are kept at the same place on the cavity wall, so the longer side of the waveguides becomes vertical and the short length of the waveguides is positioned along the horizontal plane.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/15/2015 05:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416459#msg1416459">Quote from: X_RaY on 08/15/2015 05:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Hi Shell.
At the first look the orientation of your rectangular waveguide is not the best to excite TE012 (for the other possible modes i have to think about later this day...).
For this type of waveguide the E field is in b-direction  which is the shorter side of the rectangle.. H is in a-z direction(z means propagation direction in the waveguide). For TE01 i would rotate both antennas 90deg. But of course its your turn. :)
True...
I just popped them in not worrying about correct orientation, just for looks. They will be rotated, just hadn't gotten to it. I also have a quote coming on waveguides and chances are I'll not be using these guides.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/15/2015 05:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416465#msg1416465">Quote from: WarpTech on 08/15/2015 05:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416459#msg1416459">Quote from: X_RaY on 08/15/2015 05:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Hi Shell.
At the first look the orientation of your rectangular waveguide is not the best to excite TE012 (for the other possible modes i have to think about later this day...).
For this type of waveguide the E field is in b-direction  which is the shorter side of the rectangle.. H is in a-z direction(z means propagation direction in the waveguide). For TE01 i would rotate both antennas 90deg. But of course its your turn. :)

Picture source:wikipedia

It is a hexagon. She made the sides flat to make it easier to attach 2 magnetrons opposite each other, so they will couple and synchronize. Now you're saying she should mount them to the opposing 120-deg corners?  If what you say is correct, then a rectangle or octagon would've been better than a hexagon.
Todd
What?
I mean orientation like Tajmar for the single waveguides

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/15/2015 05:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416469#msg1416469">Quote from: SeeShells on 08/15/2015 05:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416459#msg1416459">Quote from: X_RaY on 08/15/2015 05:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
Here are the force calculations corresponding to the stresses shown in http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416281#msg1416281

Some noteworthy comments:

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.

2) Due to the fact that the stress is tensile at the small base and compressive at the big base, both forces, at the small base and at the big base point in the same direction, from the small base towards the big base.  This is the first run where we encounter both forces pointing in the same direction.  This is only possible for TE modes because they have a magnetic axial field and the magnetic field is able to impart either a tensile or a compressive force on a surface (while the TM modes have electric axial fields that can only impart a compressive force on surfaces).  From the geometry, the force on the lateral conical surfaces due to the electric field must be in the opposite direction, from the big base towards the small base, countering the net force on the bases.

3) This computer run had the antenna positioned near the small end.  It will be very interesting to see whether having the antenna at the big end results in a net force in the opposite direction (as previously observed in previous runs with the antenna near the big end for TM modes) which cannot be countered by the lateral conical surfaces.

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Hi Shell.
At the first look the orientation of your rectangular waveguide is not the best to excite TE012 (for the other possible modes i have to think about later this day...).
For this type of waveguide the E field is in b-direction  which is the shorter side of the rectangle.. H is in a-z direction(z means propagation direction in the waveguide). For TE01 i would rotate both antennas 90deg. But of course its your turn. :)
True...
I just popped them in not worrying about correct orientation, just for looks. They will be rotated, just hadn't gotten to it. I also have a quote coming on waveguides and chances are I'll not be using these guides.
Why not? Its simple to use and you have a VNA, you could use the guides for tuning (impedance) Its simple to use some screws...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/15/2015 06:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
...

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Yes, I think that the best location for the antenna is near the Big End (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416350#msg1416350), and not near the Small End as in this run.

Looking forward to that 64 cycle Meep run with the antenna at the Big End to compare and most of all I look forward to the NSF-1701 and Yang/Shell tests.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/15/2015 08:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416481#msg1416481">Quote from: Rodal on 08/15/2015 06:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416450#msg1416450">Quote from: SeeShells on 08/15/2015 04:59 PM</a>
...

A very nice piece of work Dr. Rodal! I was expecting an increase in stress forces for the TE mode although not nearly this magnitude. And what is interesting the antenna is out of phase creating a shadow zone in the small cavity of decaying waveforms. Interesting.

I'm waiting for the big end run to finalize the second generation placement of the dual waveguide insertion into the cavity from a single magnetron source.

I fussed over how to make the small plate adjustable with a "Rube Goldberg" contraption on the outside of the frustum to the bottom secured plat to allow for thermal expansion of the walls and hated each iteration. I flashed on an idea of using a quartz rod which is very transparent to microwaves down through the very center, attaching the large base to it and the letting the top small base slide inside of the extended cavity. Still need to capture the small plate with a hollow threaded rod on the outside of it and a captured nut extended to the sidewalls of the extended cavity. This is where I stopped and still fleshing the little details out. The waveguides are just for looks and not representative of where the final fleshed out design will be.

Busy day today, off to lurking in the shop.

Shell
Yes, I think that the best location for the antenna is near the Big End (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416350#msg1416350), and not near the Small End as in this run.

Looking forward to that 64 cycle Meep run with the antenna at the Big End to compare and most of all I look forward to the NSF-1701 and Yang/Shell tests.
Out of state guests for the next few days. Looking like fulcrum test will be Tuesday, August 25th on NSF-1701.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/15/2015 08:39 PM
http://arxiv.org/pdf/physics/0608097v3.pdf
"Gain-assisted slow to superluminal group velocity manipul
ation in nano-waveguides"

May be interesting for somebody   ::)

PS:I don't have read the full text jet, nevertheless the headline looks very interesting.
I am too tired now, had intensive studies in roller coasters today  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/15/2015 09:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416447#msg1416447">Quote from: WarpTech on 08/15/2015 04:48 PM</a>
"Like a trombone" I said...
Todd

I'm thinking Baritone at this point...  A baritone might be big enough to allow the use of a 2.45GHz magnetron.


Here's a shiny one for 150 bucks
http://www.alibaba.com/product-detail/Baritone_210767159.html?spm=a2700.7724838.35.1.BBzfaa

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/15/2015 10:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416468#msg1416468">Quote from: flux_capacitor on 08/15/2015 05:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416465#msg1416465">Quote from: WarpTech on 08/15/2015 05:29 PM</a>
It is a hexagon. She made the sides flat to make it easier to attach 2 magnetrons opposite each other, so they will couple and synchronize.

For now SeeShells will use one single magnetron that has 2 outputs, so the waves come in a more symmetric fashion inside.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416465#msg1416465">Quote from: WarpTech on 08/15/2015 05:29 PM</a>
Now you're saying she should mount them to the opposing 120-deg corners?  If what you say is correct, then a rectangle or octagon would've been better than a hexagon.
Todd

I think X_RaY proposed to turn the waveguides 90° but they are kept at the same place on the cavity wall, so the longer side of the waveguides becomes vertical and the short length of the waveguides is positioned along the horizontal plane.
Yes, just in to take a sliver out. But like this.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/15/2015 11:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416525#msg1416525">Quote from: tleach on 08/15/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416447#msg1416447">Quote from: WarpTech on 08/15/2015 04:48 PM</a>
"Like a trombone" I said...
Todd

I'm thinking Baritone at this point...  A baritone might be big enough to allow the use of a 2.45GHz magnetron.


Here's a shiny one for 150 bucks
http://www.alibaba.com/product-detail/Baritone_210767159.html?spm=a2700.7724838.35.1.BBzfaa

A 9" Trombone works too, but I came to the same conclusion. A Baritone would work, they're just pricey.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 08/16/2015 12:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416563#msg1416563">Quote from: WarpTech on 08/15/2015 11:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416525#msg1416525">Quote from: tleach on 08/15/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416447#msg1416447">Quote from: WarpTech on 08/15/2015 04:48 PM</a>
"Like a trombone" I said...
Todd

I'm thinking Baritone at this point...  A baritone might be big enough to allow the use of a 2.45GHz magnetron.


Here's a shiny one for 150 bucks
http://www.alibaba.com/product-detail/Baritone_210767159.html?spm=a2700.7724838.35.1.BBzfaa

A 9" Trombone works too, but I came to the same conclusion. A Baritone would work, they're just pricey.
Todd

I love the idea of using brass instruments for the frustrum.

I just wonder how brass will work as the material of the frustrum?  vs copper or copper mesh?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ScottD on 08/16/2015 12:32 AM
Brass instruments have a thin lacquer coating on them.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 12:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416567#msg1416567">Quote from: Eer on 08/16/2015 12:13 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416563#msg1416563">Quote from: WarpTech on 08/15/2015 11:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416525#msg1416525">Quote from: tleach on 08/15/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416447#msg1416447">Quote from: WarpTech on 08/15/2015 04:48 PM</a>
"Like a trombone" I said...
Todd

I'm thinking Baritone at this point...  A baritone might be big enough to allow the use of a 2.45GHz magnetron.


Here's a shiny one for 150 bucks
http://www.alibaba.com/product-detail/Baritone_210767159.html?spm=a2700.7724838.35.1.BBzfaa

A 9" Trombone works too, but I came to the same conclusion. A Baritone would work, they're just pricey.
Todd

I love the idea of using brass instruments for the frustrum.

I just wonder how brass will work as the material of the frustrum?  vs copper or copper mesh?

Resistivity                                ohm-m
Pure Copper                             1.664 E-08
High Strength Yellow Brass       1.437 E-07

Ratio of resistivities       8.64
Square Root of Ratio     2.94

So using High Strength Yellow Brass implies a quality of resonance Q about 1/3 that of using pure copper

http://eddy-current.com/conductivity-of-metals-sorted-by-resistivity/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 08/16/2015 01:13 AM
Standing wave visualisation.
What do you think guys.  a suggestion?
This appears to be dirty and simple way to compare simulations to actual test data.
Inside those resonant cavities for DIY's?

https://www.youtube.com/watch?v=7FhwTelc5Tg

so for $2.00 a roll or buying some thermal A4 fax paper it chould be  a cheap test.
I could picture us doing card layers @ 25mm or 1" spacing through the  the planes.
With 60 second microwave minute bursts.
And then photo'ing  and comparing to computer based  simulation predictions on the standing wave peaks that are on this thread.

My deep concern would be the presence of water and the additional cardboard material.
And how it may interfere with the standing wave pattern and distorting the results.
 Maybe by keep the spray to very light coating it helps mitigate this.

And then the questions :
To what degree will the results be distorted?- if it's real bad-well, the idea stops here.
Or would it be a close enough to the fit to be a reasonable indicator?
Could be as simple as a calibration test between two known values help?

 -on another site with regards microwave standing waves-
 
It was motioned that thermo-chromic liquid crystal sheets could be used but that the colours may revert back quickly with in 30 seconds or so. So it maybe a struggle to get end caps off in time if using full plate bolted  copper.

 It might be o.k. though if we are using perforated copper as could see through [ $30-50 range]

http://www.thermometersite.com/temperature-research-and-testing-kits/thermochromic-liquid-crystal-sheets/detailed-product-flyer.html
and
https://www.youtube.com/watch?v=DscgYJu_HGE

Finally if ..... it all works... could we added in the list of suggested experiments in wiki?

P.S. [can you imagine the conversation afterwards.  It may go like this.
uh... look.. its a man face!.  No its a butterfly's?.. a bird..  Dang it's a BAT   how did that get in there?....] 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 01:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416573#msg1416573">Quote from: Silversheep2011 on 08/16/2015 01:13 AM</a>
Standing wave visualisation.
What do you think guys.  a suggestion?
This appears to be dirty and simple way to compare simulations to actual test data.
Inside those resonant cavities for DIY's?

so for $2.00 a roll or buying some thermal A4 fax paper it chould be  a cheap test.
...
It cannot be overemphasized how important it is to determine what mode shape is being excited in experiments and this looks like an alternative way to do it.

The only experimenters so far that have actually measured and reported a mode shape has been NASA Eagleworks that actually measured TM212 mode shape by using a thermal camera pointed at the big base.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/16/2015 01:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416570#msg1416570">Quote from: Rodal on 08/16/2015 12:37 AM</a>
Resistivity                                ohm-m
Pure Copper                             1.664 E-08
High Strength Yellow Brass       1.437 E-07

Ratio of resistivities       8.64
Square Root of Ratio     2.94

So using High Strength Yellow Brass implies a quality of resonance Q about 1/3 that of using pure copper

http://eddy-current.com/conductivity-of-metals-sorted-by-resistivity/

1/3?  That's not bad!  The (possibly) more efficient shape might give some of that loss back to you, and it would make DIY experiments MUCH easier to reproduce and... well, experiment with.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Devilstower on 08/16/2015 02:16 AM
I'm thinking of joining the ranks of experimenters.

My plan is to use a 5.8 ghz magnetron, with the goal of building a device that might be fit into a standard 1U cubesat.  Not saying that I have $70k sitting around to actually launch my little EM cube, but it seemed like a nice challenge — and at least a little different from most of the builds underway.

One thing I've been thinking about in the spirit of "I don't want most of the cube filled with frustrum" is to design the cone like one of those plastic collapsible drinking cups.  On deployment, I'd expand the frustrum (I'm thinking a cylinder of compressed nitrogen, and clips that would hold the expanded shape rather than an electromechanical system). That would allow me to save most of the space for batteries, more batteries and communications. 

So, being as I've not constructed anything electrical since my Heathkit H8 (geologist, biologist, information theory, science fiction writer guy — go buy my book "The Evolution of Everything" at an Amazon near you), can anyone give me an idea of how having three or four 1mm "rims" inside the cone would effect the behavior? Would defects of this size inside the smooth interior significantly degrade performance, at least in terms of Q? Would this stair-stepping of the surface negate the expected resonance modes of a smooth-bore cone?

Thanks. And by the way, a huge thanks for the caliber of this public discussion. I hang around here every day with the thought that it might be history in the making — and if not, at least I'll steal some convincing jargon for my next novel.



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/16/2015 02:26 AM

Quote
Resistivity                                ohm-m
Pure Copper                             1.664 E-08
High Strength Yellow Brass       1.437 E-07

Ratio of resistivities       8.64
Square Root of Ratio     2.94

So using High Strength Yellow Brass implies a quality of resonance Q about 1/3 that of using pure copper

Hmmm...

1 - Possibly a used or damaged instrument would work, seeing as we'd be concerned only with the one end?

2 - Perhaps it would be possible to silver coat the interior?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/16/2015 02:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416580#msg1416580">Quote from: ThinkerX on 08/16/2015 02:26 AM</a>
Quote
Resistivity                                ohm-m
Pure Copper                             1.664 E-08
High Strength Yellow Brass       1.437 E-07

Ratio of resistivities       8.64
Square Root of Ratio     2.94

So using High Strength Yellow Brass implies a quality of resonance Q about 1/3 that of using pure copper

Hmmm...

1 - Possibly a used or damaged instrument would work, seeing as we'd be concerned only with the one end?

2 - Perhaps it would be possible to silver coat the interior?

Brass can easily be electroplated with pure copper, or gold plated. The shape and consistency is what I like about it.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/16/2015 03:53 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.


Just to clarify,  you mean an increase of 10^4 not 10^10000. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 05:41 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
1) The force magnitude is a whooping 10,000 times higher than for previous cases.

Prof Yang has shown the end plate bounce Force is very much larger if the H field (TE mode) is doing the bounce than if the E field (TM mode) is doing the bounce.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 05:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416585#msg1416585">Quote from: WarpTech on 08/16/2015 02:48 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416580#msg1416580">Quote from: ThinkerX on 08/16/2015 02:26 AM</a>
Quote
Resistivity                                ohm-m
Pure Copper                             1.664 E-08
High Strength Yellow Brass       1.437 E-07

Ratio of resistivities       8.64
Square Root of Ratio     2.94

So using High Strength Yellow Brass implies a quality of resonance Q about 1/3 that of using pure copper

Hmmm...

1 - Possibly a used or damaged instrument would work, seeing as we'd be concerned only with the one end?

2 - Perhaps it would be possible to silver coat the interior?

Brass can easily be electroplated with pure copper, or gold plated. The shape and consistency is what I like about it.
Todd

Prof Yang used brass. Didn't say if the inside was electroplated or not.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: seggybop on 08/16/2015 07:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416575#msg1416575">Quote from: Rodal on 08/16/2015 01:31 AM</a>
The only experimenters so far that have actually measured and reported a mode shape has been NASA Eagleworks that actually measured TM212 mode shape by using a thermal camera pointed at the big base.

Thermal cameras are available pretty cheaply now as smartphone accessories. Seek Thermal (http://www.thermal.com/) and FLIR One (http://www.flir.com/home/) make the most prominent ones. I got the Seek unit a while ago for around $150 and it's worked quite well for me. The numerical accuracy of the temperature measurements can't be counted on, but for visualizing the heating patterns created by different mode shapes it should be viable.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 08:15 AM
Here is a public folder with all of Eagleworks publically posted Force measurements. As far as I know this is the 1st time all the known, public Eagleworks EMDrive Force measurement runs are available in one folder to view the results. If I have missed any, please post them so I can add them to the collection.

https://drive.google.com/folderview?id=0B7kgKijo-p0ifnFrZ2V1UmZEY25FXzNrX0hjNXJmQXR5YzRnaVBqcTdMZUhxcjVkMUUtaXc&usp=sharing

Please review. You may find the measured atmo and vac results are more positive than you thought they were and that the Force onset is very rapid.

Also note Eagleworks do a measurement system calibration pulse before and after each EMDrive test run.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 08:51 AM
Looking at all the atmo Force curves I do note the very strange one which occurred when the frustum was enclosed by foam panels. I assume EW did this to shield against air currents.

What I see is the effect of reduced acoustic vibration on the end plates reducing the necessary external vibratory Force needed to move the frustum from IDLE mode into MOTOR mode. The result is a Force generation curve suggesting the EMDrive was struggling to get into MOTOR mode as the required external vibratory Force has been very significantly reduced by the foam panel enclosure.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 10:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416597#msg1416597">Quote from: SteveD on 08/16/2015 03:53 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>

1) The force magnitude is a whooping 10,000 times higher than for previous cases.  At this point we don't know how much of this greater magnitude is due to the fact that this computer run is for twice as long a time as previous runs (with stresses that are increasing with time) and how much is due to the fact that this force is due to a transverse electric (TE) mode shape while the other ones were for transverse magnetic (TM) modes.


Just to clarify,  you mean an increase of 10^4 not 10^10000.

Yes that's what that means. Sorry but I don't understand why it needs to be clarified.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
10,000 times higher
cannot mean 10^10,000 under any interpretation I am aware of.

"Times" means multiplication:  10,000 x a means 10,000 times a

On the other hand (exponentiation) 10^10,000 reads: 10 to the power of 10,000

Hence it is not possible to confuse "10,000 times higher" with 10^10,000 or any other base raised to any other power.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/16/2015 11:19 AM
This seems highly relevant.

http://iopscience.iop.org/1367-2630/17/5/053035/pdf/1367-2630_17_5_053035.pdf

Experimental evidence for Abraham pressure of light

Keywords: momentum of light, light in media, optomechanics, optofluidics

Abstract
The question of how much momentum light carries in media has been debated for over a century.
Two rivalling theories, one from 1908 by Hermann Minkowski and the other from 1909 by Max
Abraham, predict the exact opposite when light enters an optical material: a pulling force in
Minkowskiʼs case and a pushing force in Abrahamʼs. Most experimental tests have agreed with
Minkowskiʼs theory, but here we report the first quantitative experimental evidence for Abrahamʼs
pushing pressure of light. Our results matter in optofluidics and optomechanics, and wherever light
exerts mechanical pressure.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 12:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416631#msg1416631">Quote from: RERT on 08/16/2015 11:19 AM</a>
This seems highly relevant.

http://iopscience.iop.org/1367-2630/17/5/053035/pdf/1367-2630_17_5_053035.pdf

Experimental evidence for Abraham pressure of light

Keywords: momentum of light, light in media, optomechanics, optofluidics

Abstract
The question of how much momentum light carries in media has been debated for over a century.
Two rivalling theories, one from 1908 by Hermann Minkowski and the other from 1909 by Max
Abraham, predict the exact opposite when light enters an optical material: a pulling force in
Minkowskiʼs case and a pushing force in Abrahamʼs. Most experimental tests have agreed with
Minkowskiʼs theory, but here we report the first quantitative experimental evidence for Abrahamʼs
pushing pressure of light. Our results matter in optofluidics and optomechanics, and wherever light
exerts mechanical pressure.

To put some numbers into this, n, the coefficient of refraction

(98f38596714705e32b04edea50f6aa96.png)

where c is the speed of light in vacuum and v is the phase velocity of light in the medium.

The theories of Abraham and Minkowski differ by the index of refraction (whether it should be a multiplying or a dividing factor).

For Minkowski, the momentum is:

(c1ff5716d22afbc60825ac2f70557838.png)

where h is the Planck constant, ν is the frequency of the light and c is the speed of light in vacuum.

while for Abraham, the momentum is

(f8483b16e0b0f992e8747dd81f634b29.png)

hence the momentum between Minkowski and Abraham differs by n^2

For the EM Drive operating in vacuum,

n=1

(phase velocity equals c) and the copper acts as a reflective surface and not a transparent medium.

Hence, when operating in vacuum, there is no difference between Abraham and Minkowski.

For air,

n=1.000293

(phase velocity in air is 0.029% lower than c)

Hence for air, the difference between Minkowski and Abraham is 0.057%

the paper considers liquids, for example, for water n=1.333

(phase velocity is 33% lower than c)

Hence for a hypothetical EM Drive with water inside the cavity, the difference between Minkowski and Abraham would be 78%

For the dielectric used in the NASA experiments, high density polyethylene (HDPE) the index of refraction n is less than 1.48, so the difference between Abraham and Minkowski is less than 219%

So the Abraham Minkowski controversy could enter when discussing experiments with a dielectric insert (like NASA's) but not for experiments conducted in vacuum without a dielectric insert (unless one wants to consider the tiny effect from the thin coating used on copper to prevent corrosion of copper).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/16/2015 12:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416525#msg1416525">Quote from: tleach on 08/15/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416447#msg1416447">Quote from: WarpTech on 08/15/2015 04:48 PM</a>
"Like a trombone" I said...
Todd

I'm thinking Baritone at this point...  A baritone might be big enough to allow the use of a 2.45GHz magnetron.


Here's a shiny one for 150 bucks
http://www.alibaba.com/product-detail/Baritone_210767159.html?spm=a2700.7724838.35.1.BBzfaa

Hah!  I used to play one of those!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 12:56 PM
Wikipedia

https://en.wikipedia.org/wiki/Abraham%E2%80%93Minkowski_controversy

quote:
"The Abraham–Minkowski controversy is a physics debate concerning electromagnetic momentum within dielectric media. Related theories have been put forward that, should their principles be proven, may allow the design of a reactionless drive" Wikipedia reference 7.


The Wikipedia reference 7 to Brito is particularly deceiving since this is a reference to Brito's  old 1999 paper and the article in Wikipedia fails to mention the more recent paper by Brito. Marini and Galian published 10 years later

 (
 Null Findings on Electromagnetic Inertia Thruster Experiments using a Torsion Pendulum
Hector H. Brito,* Ricardo Marini† and Eugenio S. Galian‡
45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 2 - 5 August 2009, Denver, Colorado
AIAA 2009-5070


where they nullify the Mach Lorentz Thruster type of Woodward and the Minkowski interpretation.  Later on, in a peer-reviewed paper Marini and Galian

( Ricardo L. Marini and Eugenio S. Galian.  "Torsion Pendulum Investigation of Electromagnetic Inertia Manipulation Thrusting", Journal of Propulsion and Power, Vol. 26, No. 6 (2010), pp. 1283-1290. doi: 10.2514/1.46541 http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpp  )

proceed to defenestrate the Minkowski interpretation for such a thruster with experiments that nullify such thrust.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 08/16/2015 01:38 PM
Rodal,
I hadn't realised you where replying to that last post..when I deleted it...
As on re-reading those reference's it seemed to be adding 'clutter' to the discussion
Anyway thanks for good reply.
   
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 04:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416271#msg1416271">Quote from: Rodal on 08/14/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416267#msg1416267">Quote from: TheTraveller on 08/14/2015 06:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
2) It is evident that the parallel 2-Dipole antenna severely affects the mode. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Like this?

NASA must have the RF near the big end (correct me if I'm wrong) because they have the dielectric at the small end blocking the ability to put an antenna there.

It appears (correct me if I'm wrong) that NASA has the circular loop near the conical lateral surface.  From the Meep runs I have learned that this produces all kinds of asymmetric waves that decrease the Q.  It would be much better to have the circular loop in the very center  with the axis of axi-symmetry of the cone going through the center of the circular loop antenna instead of being offset. 

I imagine that a bigger loop antenna with its center on the axis of axi-symmetry of the cone would be ideal.

I wonder whether this placement of the NASA loop feed being so asymmetric is one of the reasons that NASA was not able to robustly reproduce TE modes (the only successful TE test they were able to conduct with only 2 watts input power was the mode that produced the most force/InputPower NASA ever reported).  NASA has been running TM212 ever since.
That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell


   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 04:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416664#msg1416664">Quote from: SeeShells on 08/16/2015 04:05 PM</a>
...That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell
Shell,
I noticed that the image "ezz30-t04.png" attached in your message corresponds to the latest set calculated by Meep, inside the cavity, at longitudinal location "30".

I don't know at what time (from RF being turned ON) are these images calculated, do you know whether they correspond to a Meep total run time of 640 time slices = "64 periods" = 0.026 microseconds or whether they correspond to 320 time slices ="32 periods" = 0.013 microseconds ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/16/2015 05:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416669#msg1416669">Quote from: Rodal on 08/16/2015 04:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416664#msg1416664">Quote from: SeeShells on 08/16/2015 04:05 PM</a>
...That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell
Shell,
I noticed that the image "ezz30-t04.png" attached in your message corresponds to the latest set calculated by Meep, inside the cavity, at longitudinal location "30".

I don't know at what time (from RF being turned ON) are these images calculated, do you know whether they correspond to a Meep total run time of 640 time slices = "64 periods" = 0.026 microseconds or whether they correspond to 320 time slices ="32 periods" = 0.013 microseconds ?

That's for the 64 cycle run. It matches the image,  "ezz30-t04.png" and anyway, the 64 cycle run is the only one for which I have generated the z-30 slice data so far.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/16/2015 05:07 PM
Ref: Abraham - Minkowski

It seems to me useful to recall two things. One is that there is no argument that classical EM theory is consistent with a time varying arrangement of currents creating a non-zero net Lorentz force on matter, once retarded fields are considered. Apart from anything else, a photon rocket shows a net force on matter.

One problem with the EM drive is that there is nothing like enough radiation emitted to balance COM if it is true that p=E/c.

I find it highly encouraging that despite the protestation that the subject is well understood and the EM Drive impossible, there is ongoing controversy over what the momentum of the EM field actually is, under certain circumstances!

Finally, I understand the arithmetic on the refractive index of air bring close to one. However, it seems a reasonable hypothesis that the skin currents in the copper will create oscillating fields into, as well as out of, the copper, which might generate interesting effects.

The paper I cited gives measurements to the effect that the EM field carries differing momentum in different cases, and suggests that the difference corresponds to whether it behaves as a wave or as a particle. If the probability of such behaviour were different at each end of the frustrum, it might help explain what's observed.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 05:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416664#msg1416664">Quote from: SeeShells on 08/16/2015 04:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416271#msg1416271">Quote from: Rodal on 08/14/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416267#msg1416267">Quote from: TheTraveller on 08/14/2015 06:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
2) It is evident that the parallel 2-Dipole antenna severely affects the mode. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Like this?

NASA must have the RF near the big end (correct me if I'm wrong) because they have the dielectric at the small end blocking the ability to put an antenna there.

It appears (correct me if I'm wrong) that NASA has the circular loop near the conical lateral surface.  From the Meep runs I have learned that this produces all kinds of asymmetric waves that decrease the Q.  It would be much better to have the circular loop in the very center  with the axis of axi-symmetry of the cone going through the center of the circular loop antenna instead of being offset. 

I imagine that a bigger loop antenna with its center on the axis of axi-symmetry of the cone would be ideal.

I wonder whether this placement of the NASA loop feed being so asymmetric is one of the reasons that NASA was not able to robustly reproduce TE modes (the only successful TE test they were able to conduct with only 2 watts input power was the mode that produced the most force/InputPower NASA ever reported).  NASA has been running TM212 ever since.
That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell


 
At 180 deg phase shift all the antennas would work against the next antenna nearby.
2 of them produce a magnetic field in one direction the other 2 in the opposite. That is against the field directions/vectors of the TE01p mode.
All of them in phase will work as well

EDIT:
Its the same like the 2 antennas "look" in the opposite direction (magnetic North Pole/South Pole of the loop).
It would work for TE012 if 2 antennas are near the small end and 2 (180°Phase shifted)antennas are near the big end if they have the same orientation.

magnetic H field vectors are blue in the pic, E is red

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 05:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416669#msg1416669">Quote from: Rodal on 08/16/2015 04:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416664#msg1416664">Quote from: SeeShells on 08/16/2015 04:05 PM</a>
...That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell
Shell,
I noticed that the image "ezz30-t04.png" attached in your message corresponds to the latest set calculated by Meep, inside the cavity, at longitudinal location "30".

I don't know at what time (from RF being turned ON) are these images calculated, do you know whether they correspond to a Meep total run time of 640 time slices = "64 periods" = 0.026 microseconds or whether they correspond to 320 time slices ="32 periods" = 0.013 microseconds ?
64 cycle Shell 2D loop ant › z-30-pngs

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 05:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416681#msg1416681">Quote from: Rodal on 08/16/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416676#msg1416676">Quote from: aero on 08/16/2015 05:05 PM</a>
...
That's for the 64 cycle run. It matches the image,  "ezz30-t04.png" and anyway, the 64 cycle run is the only one for which I have generated the z-30 slice data so far.
So what is then the difference between the contents of this folder

new-csvs

with the contents of this folder

64-cycle-run ...

Both of them are in the 64 cycle Shell 2D loop ant folder
I believe they are the same but the CSV run is little different with the last set cleaned up in the post filtering showing a little better mode action, if I have the info correct. It is a little hard to keep it all straight.

The pic was for just to show a mode to explain the idea I was trying to get across and not anything else.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 05:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416685#msg1416685">Quote from: SeeShells on 08/16/2015 05:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416681#msg1416681">Quote from: Rodal on 08/16/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416676#msg1416676">Quote from: aero on 08/16/2015 05:05 PM</a>
...
That's for the 64 cycle run. It matches the image,  "ezz30-t04.png" and anyway, the 64 cycle run is the only one for which I have generated the z-30 slice data so far.
So what is then the difference between the contents of this folder

new-csvs

with the contents of this folder

64-cycle-run ...

Both of them are in the 64 cycle Shell 2D loop ant folder
I believe they are the same but the CSV run is little different with the last set cleaned up in the post filtering showing a little better mode action, if I have the info correct. It is a little hard to keep it all straight.

The pic was for just to show a mode to explain the idea I was trying to get across and not anything else.

Shell
You think about and post your ideas for discussion. I like that  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 06:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416680#msg1416680">Quote from: X_RaY on 08/16/2015 05:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416664#msg1416664">Quote from: SeeShells on 08/16/2015 04:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416271#msg1416271">Quote from: Rodal on 08/14/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416267#msg1416267">Quote from: TheTraveller on 08/14/2015 06:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
2) It is evident that the parallel 2-Dipole antenna severely affects the mode. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Like this?

NASA must have the RF near the big end (correct me if I'm wrong) because they have the dielectric at the small end blocking the ability to put an antenna there.

It appears (correct me if I'm wrong) that NASA has the circular loop near the conical lateral surface.  From the Meep runs I have learned that this produces all kinds of asymmetric waves that decrease the Q.  It would be much better to have the circular loop in the very center  with the axis of axi-symmetry of the cone going through the center of the circular loop antenna instead of being offset. 

I imagine that a bigger loop antenna with its center on the axis of axi-symmetry of the cone would be ideal.

I wonder whether this placement of the NASA loop feed being so asymmetric is one of the reasons that NASA was not able to robustly reproduce TE modes (the only successful TE test they were able to conduct with only 2 watts input power was the mode that produced the most force/InputPower NASA ever reported).  NASA has been running TM212 ever since.
That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell


 
At 180 deg phase shift all the antennas would work against the next antenna nearby.
2 of them produce a magnetic field in one direction the other 2 in the opposite. That is against the field directions/vectors of the TE01p mode.
All of them in phase will work as well

EDIT:
Its the same like the 2 antennas "look" in the opposite direction (magnetic North Pole/South Pole of the loop).
It would work for TE012 if 2 antennas are near the small end and 2 (180°Phase shifted)antennas are near the big end if they have the same orientation.
Ok i see what you're trying to say and that would work.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 06:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416691#msg1416691">Quote from: SeeShells on 08/16/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416680#msg1416680">Quote from: X_RaY on 08/16/2015 05:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416664#msg1416664">Quote from: SeeShells on 08/16/2015 04:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416271#msg1416271">Quote from: Rodal on 08/14/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416267#msg1416267">Quote from: TheTraveller on 08/14/2015 06:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416263#msg1416263">Quote from: Rodal on 08/14/2015 06:20 PM</a>
2) It is evident that the parallel 2-Dipole antenna severely affects the mode. What we learn from this is that to excite a perfect TE012 mode, a circular loop antenna is needed

Many books and articles talk about square and rectangular antennas.  This is fine for rectangular cross-section cavities, but to excite a perfect mode in a circular cross-section cavity it appears that a circular loop-antenna is needed.

Like this?

NASA must have the RF near the big end (correct me if I'm wrong) because they have the dielectric at the small end blocking the ability to put an antenna there.

It appears (correct me if I'm wrong) that NASA has the circular loop near the conical lateral surface.  From the Meep runs I have learned that this produces all kinds of asymmetric waves that decrease the Q.  It would be much better to have the circular loop in the very center  with the axis of axi-symmetry of the cone going through the center of the circular loop antenna instead of being offset. 

I imagine that a bigger loop antenna with its center on the axis of axi-symmetry of the cone would be ideal.

I wonder whether this placement of the NASA loop feed being so asymmetric is one of the reasons that NASA was not able to robustly reproduce TE modes (the only successful TE test they were able to conduct with only 2 watts input power was the mode that produced the most force/InputPower NASA ever reported).  NASA has been running TM212 ever since.
That is exactly what it looks like Dr. Rodal and yes you would have a rotational mish- mashed asymmetry of the modes with one loop.

Instead of the center placement, let's force the TE012 modes by placing 4 loops around the base circumference thereby pushing the modes to develop inline with the loops.  2 in phase and 2 out of phase by 180 degrees.  This should almost act like an active filter locking out any other modes except for the small end where they might try to develop and then be pushed into the small end.

If we still wanted to maintain TE012 and have a rotational mixer (for you rfmwguy) angle the loops 11.25 degrees (multiples of 360 measured it in the pic) close like the loop in the EW photo.

Morning coffee thoughts,
Shell


 
At 180 deg phase shift all the antennas would work against the next antenna nearby.
2 of them produce a magnetic field in one direction the other 2 in the opposite. That is against the field directions/vectors of the TE01p mode.
All of them in phase will work as well

EDIT:
Its the same like the 2 antennas "look" in the opposite direction (magnetic North Pole/South Pole of the loop).
It would work for TE012 if 2 antennas are near the small end and 2 (180°Phase shifted)antennas are near the big end if they have the same orientation.
Ok i see what you're trying to say and that would work.
At the end the pics from simulations have to look like at the picture.
TE01 have axially symmetric fields.
The antennas in our case are less than one wavelength away, and that will have influence on the pic from the simulation...

pic 1 by Rodal, thread 2: http://forum.nasaspaceflight.com/index.php?topic=36313.msg1352878#msg1352878
pic 2 form file "E106-Erlaeuterungen.pdf" could be find via I-Net search

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 06:38 PM
Where I'm coming from is I'm after as much symmetry I can expect in waveguide injection, loop, dipole or even snub. There are fewer variables to throw into the reasons for thrust. Once I get a semi-stable mode generation (TE012 is a tough one but the most promising) and we have a baseline to test from then we can add control variables to test against the baseline.

I still plan to pick this apart little by little, test by test and I want to thank you all for helping me get it right the first time.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/16/2015 06:54 PM
I was thinking of the same thing today! Rodal's drawing of the Poynting vectors (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416176#msg1416176) do not show the axial magnetic fields and transverse electric fields, so I used Eagleworks' picture.

What do we see in this cross-section animation of a TE012 mode:

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1056527;image)

As I understand we are seing electric fields periodically increasing and decreasing, and their direction according to the color (towards us or towards the screen, blue then red). Am I correct?

Below I used Eagleworks picture of TE012 that shows E-field vectors (red) and H-field vectors (blue) and drew two circular electric loops, one near the big end and one near the small end of the frustum.

The AC currents in the two loops are opposite, so the axial induced magnetic fields at each instant t are in opposite directions. I think this would excite the same TE012 mode.

Each loop is a circular loop antenna and is like a one-turn electromagnetic coil. But to prevent shadowing and disturbance of the small end (we only want that shadowing near the big end) only one loop antenna would need to exist, near the big base, as in this post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416277#msg1416277) and this one (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416337#msg1416337) by TheTraveller, where the loop antenna is located at a distance of 1/4 of the guide wavelength from the big end.

Question: What do E-fields and H-fields look like in TE013 mode?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/16/2015 06:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416681#msg1416681">Quote from: Rodal on 08/16/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416676#msg1416676">Quote from: aero on 08/16/2015 05:05 PM</a>
...
That's for the 64 cycle run. It matches the image,  "ezz30-t04.png" and anyway, the 64 cycle run is the only one for which I have generated the z-30 slice data so far.
So what is then the difference between the contents of this folder

new-csvs

with the contents of this folder

64-cycle-run ...

Both of them are in the 64 cycle Shell 2D loop ant folder

Are they in fact different? They shouldn't be. 64-cycle run csv's were made prior to changing the magnitude range of the .png files, and the new-csvs data was made in the process of making the .pngs with the new magnitude ranges. I don't have any efficient way to check whether or not they are in fact the same so I uploaded them in case you wanted to check. If they are in fact different then there is something going on with the h5totxt program that I don't understand.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 07:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416699#msg1416699">Quote from: flux_capacitor on 08/16/2015 06:54 PM</a>


Question: What do E-fields and H-fields look like in TE013 mode?
Looks equal but with one more node of the field in z-direction (in spherical case in "r" direction, and again axial symmetric)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/16/2015 07:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416703#msg1416703">Quote from: X_RaY on 08/16/2015 07:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416699#msg1416699">Quote from: flux_capacitor on 08/16/2015 06:54 PM</a>


Question: What do E-fields and H-fields look like in TE013 mode?
Looks equal but with one more node of the field in z-direction (in spherical case in "r" direction, and again axial symmetric)

Thanks that's what I thought but I was not yet really sure of all physical meanings of each component in a mode Tx,m,n,p :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 07:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416699#msg1416699">Quote from: flux_capacitor on 08/16/2015 06:54 PM</a>
Question: What do E-fields and H-fields look like in TE013 mode?

Shawyer told me he and Prof Yang moved from TM modes to TE012 and then to TE013. Understood the reason for the TM to TE mode but not the move from TE012 to TE013.

One reason I can see is designing for TE013 allows a longer frustum length and increased frustum volume, which seems to relate to higher Q.

TE013 attached.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 07:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416699#msg1416699">Quote from: flux_capacitor on 08/16/2015 06:54 PM</a>
I was thinking of the same thing today! Rodal's drawing of the Poynting vectors (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416176#msg1416176) do not show the axial magnetic fields and transverse electric fields, so I used Eagleworks' picture.

What do we see in this cross-section animation of a TE012 mode:

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1056527;image)

As I understand we are seing electric fields periodically increasing and decreasing, and their direction according to the color (towards us or towards the screen, blue then red). Am I correct?

Below I used Eagleworks picture of TE012 that shows E-field vectors (red) and H-field vectors (blue) and drew two circular electric loops, one near the big end and one near the small end of the frustum.

The AC currents in the two loops are opposite, so the axial induced magnetic fields at each instant t are in opposite directions. I think this would excite the same TE012 mode.

Each loop is a circular loop antenna and is like a one-turn electromagnetic coil. But to prevent shadowing and disturbance of the small end (we only want that shadowing near the big end) only one loop antenna would need to exist, near the big base, as in this post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416277#msg1416277) and this one (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416337#msg1416337) by TheTraveller, where the loop antenna is located at a distance of 1/4 of the guide wavelength from the big end.

Question: What do E-fields and H-fields look like in TE013 mode?

The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 07:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...

I think the antenna is like this one only bigger in diameter.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/16/2015 07:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...

I understand the loop must have a max diameter of half-wavelength (my sketch was not intended to be on scale) but I'm not sure to understand the rest… what do you think of this sketch (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416277#msg1416277) by TheTraveller then? Here it is reproduced:


          |                                                            |
         |                                                              |
        |                                                                |
==>|<=====0 <---------Loop---------> 0            |
       |      coax                                                      |               
      |_____________________________________ |

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 07:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416708#msg1416708">Quote from: TheTraveller on 08/16/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416699#msg1416699">Quote from: flux_capacitor on 08/16/2015 06:54 PM</a>
Question: What do E-fields and H-fields look like in TE013 mode?

Shawyer told me he and Prof Yang moved from TM modes to TE012 and then to TE013. Understood the reason for the TM to TE mode but not the move from TE012 to TE013.

One reason I can see is designing for TE013 allows a longer frustum length and increased frustum volume, which seems to relate to higher Q.

TE013 attached.
Bigger p value leads to smaller bandwidth,
I have checked that experimentally(in the K-Band)
The losses are bigger because the resistive skin is greater...
It's complicated...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 07:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416715#msg1416715">Quote from: flux_capacitor on 08/16/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...

I'm not sure to understand all what you said but… what do you think of this sketch (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416277#msg1416277) by TheTraveller then? Here it is reproduced:


          |                                                            |
         |                                                              |
        |                                                                |
==>|<=====0 <---------Loop---------> 0                 |
       |      coax                                                      |               
      |__________________________________ |

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 07:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416718#msg1416718">Quote from: X_RaY on 08/16/2015 07:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416708#msg1416708">Quote from: TheTraveller on 08/16/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416699#msg1416699">Quote from: flux_capacitor on 08/16/2015 06:54 PM</a>
Question: What do E-fields and H-fields look like in TE013 mode?

Shawyer told me he and Prof Yang moved from TM modes to TE012 and then to TE013. Understood the reason for the TM to TE mode but not the move from TE012 to TE013.

One reason I can see is designing for TE013 allows a longer frustum length and increased frustum volume, which seems to relate to higher Q.

TE013 attached.
Bigger p value leads to smaller bandwidth,
I have checked that experimentally(in the K-Band)
The losses are bigger because the resistive skin is greater...
It's complicated...

Yes I have seen Prof Yang's Q equation.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 07:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416715#msg1416715">Quote from: flux_capacitor on 08/16/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...

I'm not sure to understand all what you said but… what do you think of this sketch (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416277#msg1416277) by TheTraveller then? Here it is reproduced:


          |                                                            |
         |                                                              |
        |                                                                |
==>|<=====0 <---------Loop---------> 0            |
       |      coax                                                      |               
      |_____________________________________ |
No. please look at the NASAloop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture "* Loop antenna for TE01 modes.png_thumb.jpg" have the same electrical potential!

Gedankenexperiment: Using a coil and put both ends of the loop wire at the same pole of battery. How big would be the magnetic field of the coil? Right zero!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 07:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/16/2015 07:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
The 2 ends of the loop in the picture "* Loop antenna for TE01 modes.png_thumb.jpg" have the same electrical potential!
I understand now. Maybe I over-simplified by drawing but it was my intention from start to show the placement for the same kind of loop as in Eagleworks' picture, just bigger and centered around frustum's axis like in TT's sketch. I put a ring because it was plain simple, but the goal is to have a loop antenna there, with one side of the loop connected tot the ground! (and no, it should not be a coil, ok)

EDIT: LOL TT, we shouted together the same thing at the same time, so will it be heard? ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/16/2015 07:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416726#msg1416726">Quote from: flux_capacitor on 08/16/2015 07:53 PM</a>
I understand now. Maybe I over-simplified by drawing but it was my intention from start to show the placement for the same kind of loop as in Eagleworks' picture, just bigger and centered around frustum's axis like in TT's sketch. I put a ring because it was plain simple, but the goal is to have a loop antenna there, with one side of the loop connected tot the ground! (and no, it should not be a coil, ok)

Not a coil but 1 loop of a coil for sure for sure.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/16/2015 08:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
Gedankenexperiment: Using a coil and put both ends of the loop wire at the same pole of battery. How big would be the magnetic field of the coil? Right zero!

We're discussing about a super-simple thing we shouldn't normally argue about. Of course it was never intended to work that way. One thing you said retained my attention though:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
the length of the loop is max a half wavelength

Since the wavelength change according to the location where it is measured (free wavelength, guide wavelength, wavelength at the big end, wavelength at the small end, wavelength at the antenna location…) which one must be taken into account to properly design the length (diameter?) of the loop antenna at this "max half-wavelength"?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 08:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416730#msg1416730">Quote from: flux_capacitor on 08/16/2015 08:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
Gedankenexperiment: Using a coil and put both ends of the loop wire at the same pole of battery. How big would be the magnetic field of the coil? Right zero!

We're discussing about a super-simple thing we shouldn't normally argue about. Of course it was never intended to work that way. One thing you said retained my attention though:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
the length of the loop is max a half wavelength

Since the wavelength change according to the location where it is measured (free wavelength, guide wavelength, wavelength at the big end, wavelength at the small end, wavelength at the antenna location…) which one must be taken into account to properly design the length (diameter?) of the loop antenna at this "max half-wavelength"?
Yes, if you like to excite this mode at high Q.

Think in wavelength: A wave travel along a wire, the H-field around will change the direction every half wavelength.
TE01p is a axial symmetrical model.
If the H-field along the antenna changes the vector its not good...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 08:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 08:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

The chassis of the magnetron is one of the two potential (aka GND) ;)
The other switch between +Volts and -Volts against GND.

EDIT:
For the magnetron may be only half of that cycle
+Volts against GND---> nothing---> again +Volts against GND--->...
not sure jet at this point, have to restudy :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 08:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416738#msg1416738">Quote from: X_RaY on 08/16/2015 08:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

The chassis of the magnetron is one of the two potential (aka GND) ;)
The other switch between +Volts and -Volts against GND.
AKA GND isn't always ground.
https://en.wikipedia.org/wiki/Ground_loop_(electricity)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/16/2015 08:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416740#msg1416740">Quote from: SeeShells on 08/16/2015 08:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416738#msg1416738">Quote from: X_RaY on 08/16/2015 08:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

The chassis of the magnetron is one of the two potential (aka GND) ;)
The other switch between +Volts and -Volts against GND.
AKA GND isn't always ground.
https://en.wikipedia.org/wiki/Ground_loop_(electricity)
Right :) The Voltage difference predicts the current flow.

Technical(per convention) the current flow goes from the + to the - (that's historical issues and cause only a difference of the sign within calculations).
Physically the electrons travel from - to the + potential.
https://translate.google.de/translate?sl=de&tl=en&js=y&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.frustfrei-lernen.de%2Felektrotechnik%2Fstromrichtung-technisch-physikalisch.html&edit-text=&act=url

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 09:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416741#msg1416741">Quote from: X_RaY on 08/16/2015 08:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416740#msg1416740">Quote from: SeeShells on 08/16/2015 08:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416738#msg1416738">Quote from: X_RaY on 08/16/2015 08:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

The chassis of the magnetron is one of the two potential (aka GND) ;)
The other switch between +Volts and -Volts against GND.
AKA GND isn't always ground.
https://en.wikipedia.org/wiki/Ground_loop_(electricity)
Right :) The Voltage difference predicts the current flow
And that difference in potentials will and can change in a oscillatory system and cause the ground plane to oscillate with the conductive harmonic path lengths between the grounds.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/16/2015 09:10 PM

Quote
Since the wavelength change according to the location where it is measured (free wavelength, guide wavelength, wavelength at the big end, wavelength at the small end, wavelength at the antenna location…) which one must be taken into account to properly design the length (diameter?) of the loop antenna at this "max half-wavelength"?

Multiple antenna's? Use only the one you happen to need at that particular moment.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/16/2015 09:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416746#msg1416746">Quote from: ThinkerX on 08/16/2015 09:10 PM</a>
Quote
Since the wavelength change according to the location where it is measured (free wavelength, guide wavelength, wavelength at the big end, wavelength at the small end, wavelength at the antenna location…) which one must be taken into account to properly design the length (diameter?) of the loop antenna at this "max half-wavelength"?

Multiple antenna's? Use only the one you happen to need at that particular moment.

No, I wanted to mean: there are different wavelength values inside the cavity, so which value of the wavelength should be taken, to calculate the length of the loop antenna near the big base?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 09:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416701#msg1416701">Quote from: aero on 08/16/2015 06:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416681#msg1416681">Quote from: Rodal on 08/16/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416676#msg1416676">Quote from: aero on 08/16/2015 05:05 PM</a>
...
That's for the 64 cycle run. It matches the image,  "ezz30-t04.png" and anyway, the 64 cycle run is the only one for which I have generated the z-30 slice data so far.
So what is then the difference between the contents of this folder

new-csvs

with the contents of this folder

64-cycle-run ...

Both of them are in the 64 cycle Shell 2D loop ant folder

Are they in fact different? They shouldn't be. 64-cycle run csv's were made prior to changing the magnitude range of the .png files, and the new-csvs data was made in the process of making the .pngs with the new magnitude ranges. I don't have any efficient way to check whether or not they are in fact the same so I uploaded them in case you wanted to check. If they are in fact different then there is something going on with the h5totxt program that I don't understand.

The reason why I had asked for the "location 30" runs to be done for a 32 cycle instead of a 64 cycle is in order to find out whether the 10,000 fold increase in stresses and force is mainly due to the doubling of the running time or whether it is mainly due to the TE012 mode instead of a TM mode as in previous runs.

In order to find out the main reason for this 10,000 fold increase in stress and force we still need the same information to be run for a 32 cycle run to compare with the 64 cycle run.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/16/2015 09:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416750#msg1416750">Quote from: Rodal on 08/16/2015 09:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416701#msg1416701">Quote from: aero on 08/16/2015 06:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416681#msg1416681">Quote from: Rodal on 08/16/2015 05:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416676#msg1416676">Quote from: aero on 08/16/2015 05:05 PM</a>
...
That's for the 64 cycle run. It matches the image,  "ezz30-t04.png" and anyway, the 64 cycle run is the only one for which I have generated the z-30 slice data so far.
So what is then the difference between the contents of this folder

new-csvs

with the contents of this folder

64-cycle-run ...

Both of them are in the 64 cycle Shell 2D loop ant folder

Are they in fact different? They shouldn't be. 64-cycle run csv's were made prior to changing the magnitude range of the .png files, and the new-csvs data was made in the process of making the .pngs with the new magnitude ranges. I don't have any efficient way to check whether or not they are in fact the same so I uploaded them in case you wanted to check. If they are in fact different then there is something going on with the h5totxt program that I don't understand.

The reason why I had asked for the "location 30" runs to be done for a 32 cycle instead of a 64 cycle is in order to find out whether the 10,000 fold increase in stresses and force is mainly due to the doubling of the running time or whether it is mainly due to the TE012 mode instead of a TM mode as in previous runs.

In order to find out the main reason for this 10,000 fold increase in stress and force we still need the same information to be run for a 32 cycle run to compare with the 64 cycle run.

Ok - I'll see what i can do. It'll be later today or tomorrow early.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/16/2015 11:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416743#msg1416743">Quote from: SeeShells on 08/16/2015 09:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416741#msg1416741">Quote from: X_RaY on 08/16/2015 08:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416740#msg1416740">Quote from: SeeShells on 08/16/2015 08:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416738#msg1416738">Quote from: X_RaY on 08/16/2015 08:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

The chassis of the magnetron is one of the two potential (aka GND) ;)
The other switch between +Volts and -Volts against GND.
AKA GND isn't always ground.
https://en.wikipedia.org/wiki/Ground_loop_(electricity)
Right :) The Voltage difference predicts the current flow
And that difference in potentials will and can change in a oscillatory system and cause the ground plane to oscillate with the conductive harmonic path lengths between the grounds.

Many of the things being discussed (how to best excite TE01 modes, and discourage other modes) are discussed in
the excellent book by Balanis:

Advanced Engineering Electromagnetics 2nd Edition
by Constantine A. Balanis  (Author)
Hardcover: 1040 pages
Publisher: Wiley; 2 edition (January 24, 2012)
Language: English
ISBN-10: 0470589485
ISBN-13: 978-0470589489

(41Uj-prky8L._SX363_BO1,204,203,200_.jpg)

<<Although the TE0n modes are very attractive from the attenuation point of view, there are a number of problems associated with their excitation and retention.  One of the problems is that the TE01 mode, which is the first of the TE0n modes, is not the dominant mode.  Therefore, in order for this mode to be above its cut-off frequency and propagate in the waveguide, a number of other modes (such as the TE11, TM01, TE21 and TM11) with lower cutoff frequencies can also exist. Additional modes can also be present if the operating frequency is chosen well above the cutoff frequency of the TE01 mode in order to provide a margin of safety from being too close to its cutoff frequency. 
To support the TE01 mode, the waveguide must be oversized and it can support a number of other modes.  One of the problems faced with such a guide is how to excite the desired TE01 mode with sufficient  purity and suppress the others.   Another problem is how to prevent coupling of the TE01 mode and undesired modes that can exist since the guide is oversized.  The presence of the undesired modes causes not only higher losses but dispersion and attenuation distortion to the signal since each exhibits different phase velocities and attenuation.  Irregularities in the inner geometry, surface, and direction (such as bends, nonuniform cross-sections, etc.) of the waveguide are the main contributors to the coupling to the undesired modes.  However, for the guide to be of any practical use, it must be able to sustain and propagate the desired TE01 and other TE0n modes efficiently over bends of reasonable curvature.  One technique that has been implemented to achieve this is to use mode conversion before entering the corner and another conversion when exiting to convert back to the desired TE0n mode(s).

Another method that has been used to discriminate against undesired modes and avoid coupling to them is to introduce filters inside the guide that cause negligible attenuation to the desired TE0n mode(s).  The basic principle of these filters is to introduce cuts that are perpendicular to the current paths of the undesired modes and parallel to the current direction of the desired mode(s).  Since the current path of the undesired modes is along the axis (z direction)  of the guide and the path of the desired TE0n modes is along the circumference (phi direction) , a helical wound wire placed on the inside surface of the guide can serve as a filter that discourages any mode that requires an axial component of current flow but propagates the desired TE0n modes.

Another filter that can be used to suppress undesired modes is to introduce within the guide very thin baffles of lossy material that will act as attenuating sheets. The surfaces of the baffles are placed in the radial direction of the guide so that they are parallel to the Er and Ez components of the undesired modes (which will be damped) and normal to the Ephi component of the TE0n modes that will remain unaffected.  Typically, two baffles are used and are placed in a crossed pattern over the cross section of the guide.
>>

(Bold added for emphasis)
pp.498-500

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/16/2015 11:53 PM
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416759#msg1416759

Got me thinking the quartz rod through the center could support some mode filters if needed.

Nice read Doc.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 12:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.

Additionally all external wiring will be shielded and will use a 2 turn ferrite (shielded cable will circle through the ferrite donut twice) to filter out high freq noise on the shield grounds.

Of course all power leads will have high frequency decoupling capacitors and ferrite filters.

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 12:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416736#msg1416736">Quote from: SeeShells on 08/16/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416725#msg1416725">Quote from: TheTraveller on 08/16/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASA loop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.
The 2 ends of the loop in the picture have the same electrical potential!

My crude ascii drawing has failed to deliver. Bad TT bad.

The coax is to stop the feed from the side wall to the loop from radiating. One side of the loop antenna is attached to the coax hot centre feed line and the other side of the loop antenna to the coax shield.

So the same as the NASA picture, just bigger in diameter and with the short section of 2 parallel wires replaced with coax.

If I get the loop diameter and distance from the big end right, should do an excellent job at exciting TE013 mode.
I see what your doing TT but I'd wonder about ground loops with the antenna just floating out there. How do you plan to adjust for that? Are you grounding your frustum?

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.

Additionally all external wiring will be shielded and will use a 2 turn ferrite (shielded cable will circle through the ferrite donut twice) to filter out high freq noise on the shield grounds.

Of course all power leads will have high frequency decoupling capacitors and ferrite filters.

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

It sure can help TT. Also make sure you have what we called a Star ground where all grounds terminated on the same point.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 12:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416746#msg1416746">Quote from: ThinkerX on 08/16/2015 09:10 PM</a>
Quote
Since the wavelength change according to the location where it is measured (free wavelength, guide wavelength, wavelength at the big end, wavelength at the small end, wavelength at the antenna location…) which one must be taken into account to properly design the length (diameter?) of the loop antenna at this "max half-wavelength"?

Multiple antenna's? Use only the one you happen to need at that particular moment.

Slowly getting there... slowly.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 01:04 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416762#msg1416762">Quote from: SeeShells on 08/16/2015 11:53 PM</a>
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416759#msg1416759

Got me thinking the quartz rod through the center could support some mode filters if needed.

Nice read Doc.

Shell

What is your estimated max averaged frustum surface temperature when pumping your 800 watts of Rf into the frustum?

From that temperature, how much will your copper end plate diameters grow and how much longer will your copper frustum grow?

You can dramatically increase the surface emissivity by around 5x to 10x by painting the outside surface with a high carbon black paint. This higher thermal emissivity will very significantly reduce your frustum temperature rise and significantly reduce any thermal expansion.

As copper expands 0.0166mm per deg K per m, increasing the surface emissivity 5x could really work wonders for limiting thermal expansion.

On another subject, I see you are thinking about feeding the magnetron Rf into your frustum via a waveguide and not direct inject it. My concern with the waveguide is the frustum will then have an input bandwidth that may not wide enough to accept most of the magnetron output bandwidth. Surley you don't want a Q of 50 like Tajmar used? How do you intend to deal with using a waveguide feed, limited input bandwidth and getting all your magnetron energy inside your frustum?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 02:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416767#msg1416767">Quote from: TheTraveller on 08/17/2015 01:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416762#msg1416762">Quote from: SeeShells on 08/16/2015 11:53 PM</a>
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416759#msg1416759

Got me thinking the quartz rod through the center could support some mode filters if needed.

Nice read Doc.

Shell

...you are thinking about feeding the magnetron Rf into your frustum via a waveguide and not direct inject it. My concern with the waveguide is the frustum will then have an input bandwidth that may not wide enough to accept most of the magnetron output bandwidth. Surley you don't want a Q of 50 like Tajmar used? How do you intend to deal with using a waveguide feed, limited input bandwidth and getting all your magnetron energy inside your frustum?

True.  But comparing different characteristics of transmission lines one has to trade off:


Characteristic                         Coaxial                        Waveguide        Winner

Unloaded Q                               Medium                         High                  Waveguide
Power Capability                       Medium                         High                  Waveguide
Bandwidth                                Large                            Small                  Coaxial

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 03:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416767#msg1416767">Quote from: TheTraveller on 08/17/2015 01:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416762#msg1416762">Quote from: SeeShells on 08/16/2015 11:53 PM</a>
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416759#msg1416759

Got me thinking the quartz rod through the center could support some mode filters if needed.

Nice read Doc.

Shell

What is your estimated max averaged frustum surface temperature when pumping your 800 watts of Rf into the frustum?

From that temperature, how much will your copper end plate diameters grow and how much longer will your copper frustum grow?

You can dramatically increase the surface emissivity by around 5x to 10x by painting the outside surface with a high carbon black paint. This higher thermal emissivity will very significantly reduce your frustum temperature rise and significantly reduce any thermal expansion.

As copper expands 0.0166mm per deg K per m, increasing the surface emissivity 5x could really work wonders for limiting thermal expansion.

On another subject, I see you are thinking about feeding the magnetron Rf into your frustum via a waveguide and not direct inject it. My concern with the waveguide is the frustum will then have an input bandwidth that may not wide enough to accept most of the magnetron output bandwidth. Surley you don't want a Q of 50 like Tajmar used? How do you intend to deal with using a waveguide feed, limited input bandwidth and getting all your magnetron energy inside your frustum?

The end plates will grow very little or warp like copper as they are 10mm thick ceramic gold electroplated. With a TEC of 7.2x10^-6/C (40-400C) 
http://global.kyocera.com/prdct/fc/list/tokusei/bouchou/index.html

The copper side walls exceeding the top temperature expected
dl = L0 α (t1 - t0)
for 20C start
140C tops
diff in growth Y axis = .0005m
or 0.0197" inches

The connecting quartz rod locking the two plates through the centerline is a fused quartz rod. Transparent to microwaves but with a TEC or Fractional expansion per degree 0.59 C x10^-6  or about .00001m or 100um from 20-140C. The small plate is locked to the large plate and will slide in the frustum extension at the top negating the TEC of the copper side walls.

Two things on the dual waveguide inputs. One: the inputs will be a mirror of each other. Two: I plan before using the magnetron to modify the power supply to narrow the bandwidth and reduce power and go to 100% duty cycle @2.45GHz
http://www.google.com/patents/US3760291

I've tried to look at the issues in the thermal expansions of materials of the Drive and negate the ones I could and design out (ceramic plates) the ones I could.  I hope to have a good design.

Hope that helps explain the build and you know the black might be a good idea. Thanks for the inputs!



Shell

speeelings

Added
I did the calculations for the quartz rod a little differently for a temperature spread of 20-140 C TEC and came up with 0.0006m or 60um

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/17/2015 05:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/17/2015 07:34 AM
The biggest problem with a frustum is gettin frust that other people fink is real.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 07:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416798#msg1416798">Quote from: zen-in on 08/17/2015 05:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Thanks for your input.

The copper sheet is the bottom of the Faraday Cage for both the frustum and the Rf amp as well as their earth reference.

My main noise concern is what will be coming out of the DC power leads for the Rf amp and using the supply wires back to the Lithium Ion 500Wh battery packs as antenna.

I do understand the antenna design needs to be done properly. Plan to try many ideas to get the best coupling to the resonant Rf energy inside the frustum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 07:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416811#msg1416811">Quote from: deltaMass on 08/17/2015 07:34 AM</a>
The biggest problem with a frustum is gettin frust that other people think is real.

You don't accept this is real?

https://drive.google.com/folderview?id=0B7kgKijo-p0ifnFrZ2V1UmZEY25FXzNrX0hjNXJmQXR5YzRnaVBqcTdMZUhxcjVkMUUtaXc&usp=sharing

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 11:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416767#msg1416767">Quote from: TheTraveller on 08/17/2015 01:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416762#msg1416762">Quote from: SeeShells on 08/16/2015 11:53 PM</a>
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416759#msg1416759

Got me thinking the quartz rod through the center could support some mode filters if needed.

Nice read Doc.

Shell
Surley you don't want a Q of 50 like Tajmar used? How do you intend to deal with using a waveguide feed, limited input bandwidth and getting all your magnetron energy inside your frustum?

I needed to get some sleep as I was getting tired but I'm awake (for a while) and wanted to answer this question on Tajmar's build vs Shell's "Crazy Eddie" Frustum  dual symmetrically  opposed waveguides.

Tajmar was trying to excite the TE01 mode
Wiki
"A mode with one half-wave of electric field across the height of the guide and uniform electric field (zero half-waves) across the width of the guide."

There is no place I can see where he had a uniform half-wave across the cavity (guide). I see heat and destructive/constructive bouncing waveforms out of phase and not a uniform electric field anywhere. There is no symmetry in the cavity to create a stable TE01 mode.

This is the issue with injecting microwaves into a frustum the only way I could see to create a stable mode generation was opposing symmetrical waveguides which one needs to be 180 out of phase for the generation of the TE12 patterns. This is something  that hasn't been done before in a frustum and will require good tuning to be right but I think the rewards outweigh the negatives.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 11:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416811#msg1416811">Quote from: deltaMass on 08/17/2015 07:34 AM</a>
The biggest problem with a frustum is gettin frust that other people think is real.
I can get all the frust you want, it's thust that is costly.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 11:26 AM
Needs to run in internet explorer but fun java apps making waves and all kinds of things to see visually.
http://www.falstad.com/mathphysics.html

Tired now so back to bed.

Shell 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/17/2015 11:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416778#msg1416778">Quote from: Rodal on 08/17/2015 02:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416767#msg1416767">Quote from: TheTraveller on 08/17/2015 01:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416762#msg1416762">Quote from: SeeShells on 08/16/2015 11:53 PM</a>
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416759#msg1416759

Got me thinking the quartz rod through the center could support some mode filters if needed.

Nice read Doc.

Shell

...you are thinking about feeding the magnetron Rf into your frustum via a waveguide and not direct inject it. My concern with the waveguide is the frustum will then have an input bandwidth that may not wide enough to accept most of the magnetron output bandwidth. Surley you don't want a Q of 50 like Tajmar used? How do you intend to deal with using a waveguide feed, limited input bandwidth and getting all your magnetron energy inside your frustum?

True.  But comparing different characteristics of transmission lines one has to trade off:


Characteristic                         Coaxial                        Waveguide        Winner

Unloaded Q                               Medium                         High                  Waveguide
Power Capability                       Medium                         High                  Waveguide
Bandwidth                                Large                            Small                  Coaxial
Tajmar had measured loaded Q by using a Z=50 Ohm port of a network analyzer (S11). They simply use the 3dB bandwidth. They did not derive the unloaded Q!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 12:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416835#msg1416835">Quote from: X_RaY on 08/17/2015 11:55 AM</a>
Tajmar had measured loaded Q by using a Z=50 Ohm port of a network analyzer (S11). They simply use the 3dB bandwidth. They did not derive the unloaded Q!

What is the "load" on an 0 port EMDrive resonant cavity?

As far as I understand the topic, there is no load on a EMDrive cavity. It is a 0 port resonant cavity with a Rf feed point but no input nor output ports. Measuring the cavity Q via the Rf feed 3dB down points from the max return loss dB is the cavities unloaded Q.

This method to measure unloaded 0 port EMDrive resonant cavity Q is that used by Eagleworks, Shawyer, Prof Yang and Prof Tajmar.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/17/2015 12:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416837#msg1416837">Quote from: TheTraveller on 08/17/2015 12:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416835#msg1416835">Quote from: X_RaY on 08/17/2015 11:55 AM</a>
Tajmar had measured loaded Q by using a Z=50 Ohm port of a network analyzer (S11). They simply use the 3dB bandwidth. They did not derive the unloaded Q!

What is the "load" on an 0 port EMDrive resonant cavity?

As far as I understand the topic, there is no load on a EMDrive cavity. It is a 0 port resonant cavity with a Rf feed point but no input nor output ports. Measuring the cavity Q via the Rf feed 3dB down points from the max return loss dB is the cavities unloaded Q.

This method to measure unloaded 0 port EMDrive resonant cavity Q is that used by Eagleworks, Shawyer, Prof Yang and Prof Tajmar.
The plot in the paper shows S11 Measurement. (headline of the plot)
I think they had measured the S11 and after that, the magnetron was connected.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 12:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416829#msg1416829">Quote from: SeeShells on 08/17/2015 11:12 AM</a>
Tajmar was trying to excite the TE01 mode

Where in his paper does it say Tajmar tried to excite TE01 mode or any mode? Have just rechecked the latest paper and there is no mention of any excitation mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 12:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416838#msg1416838">Quote from: X_RaY on 08/17/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416837#msg1416837">Quote from: TheTraveller on 08/17/2015 12:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416835#msg1416835">Quote from: X_RaY on 08/17/2015 11:55 AM</a>
Tajmar had measured loaded Q by using a Z=50 Ohm port of a network analyzer (S11). They simply use the 3dB bandwidth. They did not derive the unloaded Q!

What is the "load" on an 0 port EMDrive resonant cavity?

As far as I understand the topic, there is no load on a EMDrive cavity. It is a 0 port resonant cavity with a Rf feed point but no input nor output ports. Measuring the cavity Q via the Rf feed 3dB down points from the max return loss dB is the cavities unloaded Q.

This method to measure unloaded 0 port EMDrive resonant cavity Q is that used by Eagleworks, Shawyer, Prof Yang and Prof Tajmar.
The plot in the paper shows S11 Measurement. (headline of the plot)
I think they had measured the S11 and after that, the magnetron was connected.

That Tajmar cavity has no holes in it, other than the waveguide feed port in the frustum side wall and at the other end, the hole to allow the magnetron antenna to get inside the connecting waveguide.

Which would suggest they removed the magnetron and built a sample probe to fit in the magnetron hole and measured the S11 return loss dB curve, which Tajmar shows in the paper and used the 3bd down points to calc the bandwidth and unloaded cavity Q.

If you look closely at the vac photographs, you can see the magnetron is sometimes on one side or the other of the frustum ends. Would guess they rotated the magnetron and it's coupling waveguide assembly to make placing it on the vac table more stable.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/17/2015 01:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416840#msg1416840">Quote from: TheTraveller on 08/17/2015 12:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416838#msg1416838">Quote from: X_RaY on 08/17/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416837#msg1416837">Quote from: TheTraveller on 08/17/2015 12:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416835#msg1416835">Quote from: X_RaY on 08/17/2015 11:55 AM</a>
Tajmar had measured loaded Q by using a Z=50 Ohm port of a network analyzer (S11). They simply use the 3dB bandwidth. They did not derive the unloaded Q!

What is the "load" on an 0 port EMDrive resonant cavity?

As far as I understand the topic, there is no load on a EMDrive cavity. It is a 0 port resonant cavity with a Rf feed point but no input nor output ports. Measuring the cavity Q via the Rf feed 3dB down points from the max return loss dB is the cavities unloaded Q.

This method to measure unloaded 0 port EMDrive resonant cavity Q is that used by Eagleworks, Shawyer, Prof Yang and Prof Tajmar.
The plot in the paper shows S11 Measurement. (headline of the plot)
I think they had measured the S11 and after that, the magnetron was connected.

That Tajmar cavity has no holes in it, other than the waveguide feed port in the frustum side wall and at the other end, the hole to allow the magnetron antenna to get inside the connecting waveguide.

Which would suggest they removed the magnetron and built a sample probe to fit in the magnetron hole and measured the S11 return loss dB curve, which Tajmar shows in the paper and used the 3bd down points to calc the bandwidth and unloaded cavity Q.

If you look closely at the vac photographs, you can see the magnetron is sometimes on one side or the other of the frustum ends. Would guess they rotated the magnetron and it's coupling waveguide assembly to make placing it on the vac table more stable.
IMHO the simplest way is to use a coaxial to waveguide connector instead the magnetron for the measurements.

And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 02:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416846#msg1416846">Quote from: X_RaY on 08/17/2015 01:15 PM</a>
And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

Thanks for the paper.

After going through it side by side to a google translate version it seems you are saying the unloaded cavity Q is:

Q0 = (2 * Pi * Stored Energy) / Energy loss per cycle

and that the Q0 value can't be accurately measured via S11 max return loss dB at the 3dB down points?

Correct?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/17/2015 02:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416862#msg1416862">Quote from: TheTraveller on 08/17/2015 02:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416846#msg1416846">Quote from: X_RaY on 08/17/2015 01:15 PM</a>
And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

Thanks for the paper.

After going through it side by side to a google translate version it seems you are saying the unloaded cavity Q is:

Q0 = (2 * Pi * Stored Energy) / Energy loss per cycle

and that the Q0 value can't be accurately measured via S11 max return loss dB at the 3dB down points?

Correct?
Only for the coupling factor equals to 1 the full 1/sqrt(2) BW is direct usable. The coupling factor can be derived from the measurements. Sorry the paper is german but i never find a better instructions manual. :)
Please look at page 21 in the green box..

And Q_0=Q*(1+coupling factor)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 02:56 PM

Back from the Dresden front! Martin Tajmar sent me an email today where he says he measured the internal height of his frustum. It seems he went to the lab to measure it himself before his student came back from holidays ;)

Quote from: Martin Tajmar
I measured it: the internal height is 72.8 mm (after adjustment for better resonance). Between the Cavity and the waveguide we used an adapter. The measures are all correct. We simulated it in COMSOL and also Shawyer with his calculation program assured us that the dimensions we used were correct.

So the official internal dimensions from Tajmar are now:

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

Can you guys verify this cavity resonates in your frustumator software? :)

EDIT: A WR340 waveguide measures 86.36 x 43.18 mm so Tajmar used a coupling adapter reducing the waveguide.

http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412868#msg1412868

According to TheTraveller's spreadsheet, based on those dimensions

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

with spherical ends, what mode shape did Tajmar excite?


According to my calculations it is (the equivalent of cylindrical mode) TM010 at ~2.45 GHz  (*)

the lowest transverse magnetic mode possible.

I have modified the EM Drive wiki (that had TE111 based on a longer length of 0.1008 m instead of 0.0728m, and Db=0.1062m instead of 0.1082m and Ds=0.075m instead of 0.077m) to show these dimensions and mode shape.

_____________
(*) I write "the equivalent" because this mode is not constant in the longitudinal direction.  It is impossible for a mode to be constant in the longitudinal direction for a truncated cone.  I write "the equivalent" because this is the lowest TM mode for the truncated cone. It is a degenerate mode that corresponds to TM010 for a cylinder.

(**) This is based on the stated assumption by FluxCapacitor that Tajmar used a coupling adapter reducing the waveguide WR340 that measures 86.36 x 43.18 mm.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=37642.0;attach=1052888;image)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 03:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416868#msg1416868">Quote from: Rodal on 08/17/2015 02:56 PM</a>
with spherical ends, what mode shape did Tajmar excite?[/b]

Where did Prof Tajmar say the end plates had a spherical curve?

Did I miss some info here on the forum as I can't find any such mention in the original or updated paper?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/17/2015 03:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416868#msg1416868">Quote from: Rodal on 08/17/2015 02:56 PM</a>
Back from the Dresden front! Martin Tajmar sent me an email today where he says he measured the internal height of his frustum. It seems he went to the lab to measure it himself before his student came back from holidays ;)

Quote from: Martin Tajmar
I measured it: the internal height is 72.8 mm (after adjustment for better resonance). Between the Cavity and the waveguide we used an adapter. The measures are all correct. We simulated it in COMSOL and also Shawyer with his calculation program assured us that the dimensions we used were correct.

So the official internal dimensions from Tajmar are now:

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

Can you guys verify this cavity resonates in your frustumator software? :)

EDIT: A WR340 waveguide measures 86.36 x 43.18 mm so Tajmar used a coupling adapter reducing the waveguide.

http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412868#msg1412868

According to TheTraveller's spreadsheet, based on those dimensions

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

with spherical ends, what mode shape did Tajmar excite?


According to my calculations it is (the equivalent of cylindrical mode) TM010 at ~2.45 GHz  (*)

the lowest transverse magnetic mode possible.

I have modified the EM Drive wiki (that had TE111 based on a longer length of 0.1008 m instead of 0.0728m, and Db=0.1062m instead of 0.1082m and Ds=0.075m instead of 0.077m) to show these dimensions and mode shape.

_____________
(*) I write "the equivalent" because this mode is not constant in the longitudinal direction.  It is impossible for a mode to be constant in the longitudinal direction for a truncated cone.  I write "the equivalent" because this is the lowest TM mode for the truncated cone. It is a degenerate mode that corresponds to TM010 for a cylinder.
If this is true (TM010) i don't understand the orientation of the coupling waveguide, its the complete wrong orientation to excite this mode! May be thats why they have so small Q value ????????????

In a cylinder this mode do not depend on the length.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 03:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416869#msg1416869">Quote from: TheTraveller on 08/17/2015 03:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416868#msg1416868">Quote from: Rodal on 08/17/2015 02:56 PM</a>
with spherical ends, what mode shape did Tajmar excite?[/b]

Where did Prof Tajmar say the end plates had a spherical curve?

Did I miss some info here on the forum as I can't find any such mention in the original or updated paper?

My recollection is that the information (spherical ends and dimensions) is the product of personal e-mails exchanged between FluxCapacitor and Tajmar, if my memory is correct.

FluxCapacitor to confirm...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 03:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416870#msg1416870">Quote from: X_RaY on 08/17/2015 03:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416868#msg1416868">Quote from: Rodal on 08/17/2015 02:56 PM</a>
Back from the Dresden front! Martin Tajmar sent me an email today where he says he measured the internal height of his frustum. It seems he went to the lab to measure it himself before his student came back from holidays ;)

Quote from: Martin Tajmar
I measured it: the internal height is 72.8 mm (after adjustment for better resonance). Between the Cavity and the waveguide we used an adapter. The measures are all correct. We simulated it in COMSOL and also Shawyer with his calculation program assured us that the dimensions we used were correct.

So the official internal dimensions from Tajmar are now:

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

Can you guys verify this cavity resonates in your frustumator software? :)

EDIT: A WR340 waveguide measures 86.36 x 43.18 mm so Tajmar used a coupling adapter reducing the waveguide.

http://forum.nasaspaceflight.com/index.php?topic=37642.msg1412868#msg1412868

According to TheTraveller's spreadsheet, based on those dimensions

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

with spherical ends, what mode shape did Tajmar excite?


According to my calculations it is (the equivalent of cylindrical mode) TM010 at ~2.45 GHz  (*)

the lowest transverse magnetic mode possible.

I have modified the EM Drive wiki (that had TE111 based on a longer length of 0.1008 m instead of 0.0728m, and Db=0.1062m instead of 0.1082m and Ds=0.075m instead of 0.077m) to show these dimensions and mode shape.

_____________
(*) I write "the equivalent" because this mode is not constant in the longitudinal direction.  It is impossible for a mode to be constant in the longitudinal direction for a truncated cone.  I write "the equivalent" because this is the lowest TM mode for the truncated cone. It is a degenerate mode that corresponds to TM010 for a cylinder.
If this is true (TM010) i don't understand the orientation of the coupling waveguide, its the complete wrong orientation to excite this mode! May be thats why they have so small Q value ????????????

In a cylinder this mode do not depend on the length.

The calculated TE111 resonance with this short length is at a higher frequency: 2.815 GHz.  The TM010 resonance is at 2.43GHz with the dimensions provided by FluxCapacitor.

Maybe they didn't excite TE111 or TM010 well? Maybe they had TE111 mode participation at a small amplitude?

Maybe Tajmar's measurement is incorrect, the real length is 0.1 m and therefore they excited TE111 ?

Concerning <<In a cylinder this mode do not depend on the length.>> that's why I wrote the note (this TM mode for a truncated cone DOES depend on length):

(*) I write "the equivalent" because this mode is not constant in the longitudinal direction.  It is impossible for a mode to be constant in the longitudinal direction for a truncated cone.  I write "the equivalent" because this is the lowest TM mode for the truncated cone. It is a degenerate mode that corresponds to TM010 for a cylinder.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 03:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416866#msg1416866">Quote from: X_RaY on 08/17/2015 02:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416862#msg1416862">Quote from: TheTraveller on 08/17/2015 02:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416846#msg1416846">Quote from: X_RaY on 08/17/2015 01:15 PM</a>
And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

Thanks for the paper.

After going through it side by side to a google translate version it seems you are saying the unloaded cavity Q is:

Q0 = (2 * Pi * Stored Energy) / Energy loss per cycle

and that the Q0 value can't be accurately measured via S11 max return loss dB at the 3dB down points?

Correct?
Only for the coupling factor equals to 1 the full 1/sqrt(2) BW is direct usable. The coupling factor can be derived from the measurements. Sorry the paper is german but i never find a better instructions manual. :)
Please look at page 21 in the green box..

And Q_0=Q*(1+coupling factor)

That paper is GOLD, even if it is in technical German. Split screening with the Google translation it reads fine.

Nice how it ties together the coupling factor k, the reflection coefficient p and the various forms of Q.

I note the reflection coefficient p can be calculated from the S11 max return loss dB at resonance and from that p value, the coupling factor k can be calculated and from that k value, the unloaded cavity Q can be calculated from the Q measured via the 3dB off the max return loss dB.

Correct?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 08/17/2015 03:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416798#msg1416798">Quote from: zen-in on 08/17/2015 05:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Quite right - there is a very significant difference between power grounding and RF grounding.   At the appoximately 12cm wavelengths most folks are working with (2.45 Ghz or thereabout) any ground lead longer than about 6cm is also a pretty decent radiator.   Google RF grounding - there is wealth of info about it.   Power and safety ground are also very important.

Just a comment from those using loop antennas.   Loop antennas are magnetic antenna and work differently from antennas like dipoles and monopoles.   The common circumference for loop antennas is on the order of 1 lambda not lambda/2.   A half wavelength circmumference will have a VERY high input impedance and will be hard to couple.   A full wavelength loop will be significantly closer to 50 ohms, although wavelength variations due to excited mode and geometry of the cavity will also  have significant effects.     I will try to model up some example loops and patterns later today/tonight when I have access to the software.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 03:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416872#msg1416872">Quote from: Rodal on 08/17/2015 03:17 PM</a>
My recollection is that the information (spherical ends and dimensions) is the product of personal e-mails exchanged between FluxCapacitor and Tajmar, if my memory is correct.

FluxCapacitor to confirm...

Found it.

http://forum.nasaspaceflight.com/index.php?topic=37642.msg1411835#msg1411835

Spherical end plates seems so wrong when Prof Tajmar's frustum need a low Q to be able to accept all the wide band Rf the magnetron can produce. Something is not right.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/17/2015 03:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416877#msg1416877">Quote from: graybeardsyseng on 08/17/2015 03:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416798#msg1416798">Quote from: zen-in on 08/17/2015 05:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Quite right - there is a very significant difference between power grounding and RF grounding.   At the appoximately 12cm wavelengths most folks are working with (2.45 Ghz or thereabout) any ground lead longer than about 6cm is also a pretty decent radiator.   Google RF grounding - there is wealth of info about it.   Power and safety ground are also very important.

Just a comment from those using loop antennas.   Loop antennas are magnetic antenna and work differently from antennas like dipoles and monopoles.   The common circumference for loop antennas is on the order of 1 lambda not lambda/2.   A half wavelength circmumference will have a VERY high input impedance and will be hard to couple.   A full wavelength loop will be significantly closer to 50 ohms, although wavelength variations due to excited mode and geometry of the cavity will also  have significant effects.     I will try to model up some example loops and patterns later today/tonight when I have access to the software.

Herman

The ground plane is approx 0.6m in diameter, as a solid copper sheet. It forms the bottom of the fine copper mesh Faraday Cages around the frustum and the Rf amp. Should be fairly difficult for such a large ground plane to resonate and radiate or form significant Dc ground offset nodes at 2.45GHz. Seems I will find out.

Look forward to your loop examples.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 04:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416881#msg1416881">Quote from: TheTraveller on 08/17/2015 03:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416872#msg1416872">Quote from: Rodal on 08/17/2015 03:17 PM</a>
My recollection is that the information (spherical ends and dimensions) is the product of personal e-mails exchanged between FluxCapacitor and Tajmar, if my memory is correct.

FluxCapacitor to confirm...

Found it.

http://forum.nasaspaceflight.com/index.php?topic=37642.msg1411835#msg1411835

Spherical end plates seems so wrong when Prof Tajmar's frustum need a low Q to be able to accept all the wide band Rf the magnetron can produce. Something is not right.
TE010 left out a 0 in the middle of the night. It was the best gesstimate.
But he did PM email that he had spherical endplates.
And you cannot argue that the insertion point was a good thing.

You know being critiqued by engineers and physicists? The bad things and the good things?
 They all think they can do it better, faster, bigger and more powerful, they all think they they can spot errors from a 20/20 hindsight (and they can). The good thing is we learn.

I want to say thanks for all those here who have helped not only me but others understand and I can't say it loud enough!!!

Shell 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 04:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416877#msg1416877">Quote from: graybeardsyseng on 08/17/2015 03:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416798#msg1416798">Quote from: zen-in on 08/17/2015 05:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Quite right - there is a very significant difference between power grounding and RF grounding.   At the appoximately 12cm wavelengths most folks are working with (2.45 Ghz or thereabout) any ground lead longer than about 6cm is also a pretty decent radiator.   Google RF grounding - there is wealth of info about it.   Power and safety ground are also very important.

Just a comment from those using loop antennas.   Loop antennas are magnetic antenna and work differently from antennas like dipoles and monopoles.   The common circumference for loop antennas is on the order of 1 lambda not lambda/2.   A half wavelength circmumference will have a VERY high input impedance and will be hard to couple.   A full wavelength loop will be significantly closer to 50 ohms, although wavelength variations due to excited mode and geometry of the cavity will also  have significant effects.     I will try to model up some example loops and patterns later today/tonight when I have access to the software.

Herman

I thought a 1/10 wave loop or even a simulating square loop would work well and aero and imbfan have tried to model it in meep, although it's a very tough nut to crack in the meep software.

I would love to see your models.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/17/2015 04:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416877#msg1416877">Quote from: graybeardsyseng on 08/17/2015 03:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416798#msg1416798">Quote from: zen-in on 08/17/2015 05:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Quite right - there is a very significant difference between power grounding and RF grounding.   At the appoximately 12cm wavelengths most folks are working with (2.45 Ghz or thereabout) any ground lead longer than about 6cm is also a pretty decent radiator.   Google RF grounding - there is wealth of info about it.   Power and safety ground are also very important.

Just a comment from those using loop antennas.   Loop antennas are magnetic antenna and work differently from antennas like dipoles and monopoles.   The common circumference for loop antennas is on the order of 1 lambda not lambda/2.   A half wavelength circmumference will have a VERY high input impedance and will be hard to couple.   A full wavelength loop will be significantly closer to 50 ohms, although wavelength variations due to excited mode and geometry of the cavity will also  have significant effects.     I will try to model up some example loops and patterns later today/tonight when I have access to the software.

Herman
It will be interesting to experiment with loops versus radomes and other monopoles. Loops are difficult to transition from a magnetron source, guess its why I decided to use the factory 'dome.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 08/17/2015 06:35 PM
Question for folks here:  do we know which result parameters from the Meep (or other simulation software) represent "goodness", predicting desirable performance?  High Q?  Big Pointng Vector? Or even some dynamic pattern?

I don't have the physics nor electrical engineering chops to have a clue what this all means, what's good, what's bad.

But I have some experience with some interesting technologies, including neural networks and genetic algorithms, that are really "artificial stupidity" emulators - Genetic algorithms, in particular, constitute wide scope search algorithms that are sometimes able to solve questions we don't know how to solve.  They can be used to explore large search spaces, like the field of parameters governing the size, shape, material, frequency, power and relative humidity, if you like.  Whatever you can crank into your evaluation function (which, for example, might be a Meep run).

If someone else can identify the range of interesting input parameters, and a way to compare outputs (this is better than that, for some reason you tell me, based on some output value) - well, then we could attempt to evolve solutions (even absent understanding of the empirical reason for changes in one way or another) using genetic mutation (random variation) and cross fertilization (sub-solution parameter exchange).  The result of the mutation and cross fertilization would be run through tournament-style competitions against previously known models, seeking those changes than improve the output results.

I'm not in a position to help program control files to accomplish something (like testing 2 or 3 antennae, or their shape, or position) - but I could help to figure out how to drive an automated genetic algorithm driving Meep.

If there's interest, PM me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/17/2015 06:42 PM

So:

Frustrum Big Diameter 0.6963m
Frustrum Small Diameter 0.3953m
Frustrum Centre Length 0.5692m
930MHz @ TE012

Should work better than

Frustrum Big Diameter 0.4335m
Frustrum Small Diameter 0.2461m
Frustrum Centre Length 0.3543m
Frequency: 932.3Hz @ TM011

??

I wonder if TE012 is just better than TM011 which is why at the same frequency; larger frustrum works better.

I still don't get the "vibration" issue - I can kind of see how resonance = fluidization of photons but I do not see why you need the vibration (re - foam seemed to limit performance).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416603#msg1416603">Quote from: TheTraveller on 08/16/2015 05:41 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443">Quote from: Rodal on 08/15/2015 04:21 PM</a>
1) The force magnitude is a whooping 10,000 times higher than for previous cases.

Prof Yang has shown the end plate bounce Force is very much larger if the H field (TE mode) is doing the bounce than if the E field (TM mode) is doing the bounce.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/17/2015 06:51 PM
@ Dr. Rodal,
I uploaded the csv files of slice z-30 for the 32 cycle Yang-Shell run, here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing)

Let me know if there are any problems with the csvs. The pngs will follow later.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 08:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416941#msg1416941">Quote from: aero on 08/17/2015 06:51 PM</a>
@ Dr. Rodal,
I uploaded the csv files of slice z-30 for the 32 cycle Yang-Shell run, here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing)

Let me know if there are any problems with the csvs. The pngs will follow later.

Preliminary assessment of these data reveals that the roughly 10,000 fold increase in force of the TE mode case at 64 cycles compared to the TM mode at 32 cycles is due to:

1) Doubling the run time from the time that the RF feed was turned ON to time OFF: roughly  500 times increase in force

2) TE instead of TM mode: roughly 20 times increase in force

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 08:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416964#msg1416964">Quote from: Rodal on 08/17/2015 08:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416941#msg1416941">Quote from: aero on 08/17/2015 06:51 PM</a>
@ Dr. Rodal,
I uploaded the csv files of slice z-30 for the 32 cycle Yang-Shell run, here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing)

Let me know if there are any problems with the csvs. The pngs will follow later.

Preliminary assessment of these data reveals that the roughly 10,000 fold increase in force of the TE mode case at 64 cycles compared to the TM mode at 32 cycles is due to:

1) Doubling the run time from the time that the RF feed was turned ON to time OFF: roughly  500 times increase in force

2) TE instead of TM mode: roughly 20 times increase in force
Whew, honestly the 10k increase was a little unnerving. 2-3x I could deal with and 20 is still high but real world testing will show the true numbers.

In for a bit. Pouring quikrete into my anti-vibration platforms. The thin plastic wasn't good enough for me so I took them apart and laying down a foundation layer of concrete to stiffen them and add some weight, but still allow the rest of the antivibration system to work. They will need to sit on a leveled platform for at least 72 hours. Oh and I also measured and weighted each one. And each one will be sitting on 5 hockey pucks of sorbothane when they are done.

Shell

 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/17/2015 09:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416874#msg1416874">Quote from: TheTraveller on 08/17/2015 03:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416866#msg1416866">Quote from: X_RaY on 08/17/2015 02:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416862#msg1416862">Quote from: TheTraveller on 08/17/2015 02:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416846#msg1416846">Quote from: X_RaY on 08/17/2015 01:15 PM</a>
And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

Thanks for the paper.

After going through it side by side to a google translate version it seems you are saying the unloaded cavity Q is:

Q0 = (2 * Pi * Stored Energy) / Energy loss per cycle

and that the Q0 value can't be accurately measured via S11 max return loss dB at the 3dB down points?

Correct?
Only for the coupling factor equals to 1 the full 1/sqrt(2) BW is direct usable. The coupling factor can be derived from the measurements. Sorry the paper is german but i never find a better instructions manual. :)
Please look at page 21 in the green box..

And Q_0=Q*(1+coupling factor)

That paper is GOLD, even if it is in technical German. Split screening with the Google translation it reads fine.

Nice how it ties together the coupling factor k, the reflection coefficient p and the various forms of Q.

I note the reflection coefficient p can be calculated from the S11 max return loss dB at resonance and from that p value, the coupling factor k can be calculated and from that k value, the unloaded cavity Q can be calculated from the Q measured via the 3dB off the max return loss dB.

Correct?

Is there a list of papers that have been deemed likely relevant somewhere on the wiki?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/17/2015 09:28 PM

How long is a "cycle"? Doesn't bode well for attempting a high powered 10 microsecond shot then? How many cycles do you get in (assume industrial relay)?


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416964#msg1416964">Quote from: Rodal on 08/17/2015 08:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416941#msg1416941">Quote from: aero on 08/17/2015 06:51 PM</a>
@ Dr. Rodal,
I uploaded the csv files of slice z-30 for the 32 cycle Yang-Shell run, here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing)

Let me know if there are any problems with the csvs. The pngs will follow later.

Preliminary assessment of these data reveals that the roughly 10,000 fold increase in force of the TE mode case at 64 cycles compared to the TM mode at 32 cycles is due to:

1) Doubling the run time from the time that the RF feed was turned ON to time OFF: roughly  500 times increase in force

2) TE instead of TM mode: roughly 20 times increase in force

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 09:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416964#msg1416964">Quote from: Rodal on 08/17/2015 08:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416941#msg1416941">Quote from: aero on 08/17/2015 06:51 PM</a>
@ Dr. Rodal,
I uploaded the csv files of slice z-30 for the 32 cycle Yang-Shell run, here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing)

Let me know if there are any problems with the csvs. The pngs will follow later.

Preliminary assessment of these data reveals that the roughly 10,000 fold increase in force of the TE mode case at 64 cycles compared to the TM mode at 32 cycles is due to:

1) Doubling the run time from the time that the RF feed was turned ON to time OFF: roughly  500 times increase in force

2) TE instead of TM mode: roughly 20 times increase in force

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416968#msg1416968">Quote from: SeeShells on 08/17/2015 08:20 PM</a>
...Whew, honestly the 10k increase was a little unnerving. 2-3x I could deal with and 20 is still high but real world testing will show the true numbers...

The 20-fold increase for TE012 as compared to the TM113 mode makes eminent sense:

1) As remarked by TheTraveller  (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416603#msg1416603), Prof. Yang reported that her Finite Element Analysis shows

Quote
The thrust curves demonstrate that on the surfaces of the major and minor end plates the magnetic thrust (due to TE modes) is two orders of magnitude higher than the electric thrust (due to TM modes)
[quotes added by me for clarity, bold added for emphasis]

Two orders of magnitude means 100 times greater magnitude force for TE modes than for TM modes

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057003,3Bimage.pagespeed.ic.TVxGf41Rb-.webp)

2) As shown in the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results)

The only experiment conducted by NASA Eagleworks using a TE mode (TE012 with a dielectric) resulted in

TE012  21 mN/kW

compared  to

TM212  3 to 5 mN/KW

//////////////////////////////////////////////

So Prof. Yang described a two orders of magnitude increase in force of TE modes compared to TM modes, while NASA's experiments (with a dielectric !!! ) found an increase of 4 to 7 times .

(Take into account that dielectrics are best used with TM modes rather than TE modes, so that the increase in force due to TE over TM modes without a dielectric is expected to be greater than the 4 to 7 times found by NASA)

Yes, a factor of 20-fold increase makes sense and is further evidence of the utility of the Meep runs post-processed with Wolfram Mathematica.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 09:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417000#msg1417000">Quote from: Rodal on 08/17/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416964#msg1416964">Quote from: Rodal on 08/17/2015 08:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416941#msg1416941">Quote from: aero on 08/17/2015 06:51 PM</a>
@ Dr. Rodal,
I uploaded the csv files of slice z-30 for the 32 cycle Yang-Shell run, here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfnJnUUVsTUR6ZmdkRnZFY1l5SnFNT05ZUEdRWHQ5VzJ4cFlneE5WOFZyQWc&usp=sharing)

Let me know if there are any problems with the csvs. The pngs will follow later.

Preliminary assessment of these data reveals that the roughly 10,000 fold increase in force of the TE mode case at 64 cycles compared to the TM mode at 32 cycles is due to:

1) Doubling the run time from the time that the RF feed was turned ON to time OFF: roughly  500 times increase in force

2) TE instead of TM mode: roughly 20 times increase in force

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416968#msg1416968">Quote from: SeeShells on 08/17/2015 08:20 PM</a>
...Whew, honestly the 10k increase was a little unnerving. 2-3x I could deal with and 20 is still high but real world testing will show the true numbers...

The 20-fold increase for TE012 as compared to the TM113 mode makes eminent sense:

1) As remarked by TheTraveller  (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416603#msg1416603), Prof. Yang reported that her Finite Element Analysis shows

Quote
The thrust curves demonstrate that on the surfaces of the major and minor end plates the magnetic thrust (due to TE modes) is two orders of magnitude higher than the electric thrust (due to TM mode s)
[quotes added by me for clarity, bold added for emphasis]

Two orders of magnitude means 100 times greater magnitude force for TE modes than for TM modes

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057003,3Bimage.pagespeed.ic.TVxGf41Rb-.webp)

2) As shown in the EM Drive Wiki ( http://emdrive.wiki/Experimental_Results)

The only experiment conducted by NASA Eagleworks using a TE mode (TE012 with a dielectric) resulted in

TE012  21 mN/kW

compared  to

TM212  3 to 5 mN/KW
Thank you for posting these numbers again, we all forget so quickly.

I hope it can keep that scale through higher power levels is what I'm thinking Doc. Scalability has seemed to be a issue in one way or another but testing will show the truth and I'll do my darned best to make it so.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/17/2015 10:00 PM
I am looking forward to the day when I can post

Engage!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 10:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416968#msg1416968">Quote from: SeeShells on 08/17/2015 08:20 PM</a>
...Pouring quikrete into my anti-vibration platforms. The thin plastic wasn't good enough for me so I took them apart and laying down a foundation layer of concrete to stiffen them and add some weight, but still allow the rest of the antivibration system to work. They will need to sit on a leveled platform for at least 72 hours. Oh and I also measured and weighted each one. And each one will be sitting on 5 hockey pucks of sorbothane when they are done.

Shell

I had to look that up :)

Sorbothane is the tradename for a polyether-based polyurethane material with a huge damping material property:

 tan delta = 0.5

Lots of engineering properties for Sorbothane here:  http://www.lrcltd.co.uk/products/sorbothane_c.php

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 08/17/2015 10:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417013#msg1417013">Quote from: deltaMass on 08/17/2015 10:00 PM</a>
I am looking forward to the day when I can post

Engage!

I would just like to be able to follow what people are saying. The forum's content really has surpassed my ability to understand what's going on.

Are we closer to knowing if there's something real here after all or not?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 10:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417015#msg1417015">Quote from: tchernik on 08/17/2015 10:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417013#msg1417013">Quote from: deltaMass on 08/17/2015 10:00 PM</a>
I am looking forward to the day when I can post

Engage!

I would just like to be able to follow what people are saying. The forum's content really has surpassed my ability to understand what's going on.

Are we closer to knowing if there's something real here after all or not?
I'm closer.   Waiting for rfmwguy and Shell...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/17/2015 10:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417016#msg1417016">Quote from: Rodal on 08/17/2015 10:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417015#msg1417015">Quote from: tchernik on 08/17/2015 10:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417013#msg1417013">Quote from: deltaMass on 08/17/2015 10:00 PM</a>
I am looking forward to the day when I can post

Engage!

I would just like to be able to follow what people are saying. The forum's content really has surpassed my ability to understand what's going on.

Are we closer to knowing if there's something real here after all or not?
I'm closer.   Waiting for rfmwguy and Shell...
Re-setup of test stand begins tomorrow with some mods, oil bath dampener, beam support wires, counterweight attachment, laser pointer remount, mirror on tripod and tripod mounted target paper. Galinstan not yet arrived. Lots of minor stuff before test a week from tomorrow...plus house guests...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/17/2015 11:13 PM
@Dr. Rodal,

You had such a dramatic change between the 32 and 64 cycle runs that I went ahead and uploaded the csv files for the 128 cycle run. png views will be later. It is the same model as before, Yang-Shell SE 2d dipole antenna. Note that I changed the naming convention slightly. I replaced the SE and BE (big and small end indicators) with the actual row numbers, z15, z214 - and z30 is included.

https://drive.google.com/folderview?id=0B1XizxEfB23tfk81T1VtcDhjYzEyWjV6MEtBel9Fd3VQalhRWXFGU3k2VUVfZ0c4LTZxeGc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfk81T1VtcDhjYzEyWjV6MEtBel9Fd3VQalhRWXFGU3k2VUVfZ0c4LTZxeGc&usp=sharing)

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 08/17/2015 11:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416934#msg1416934">Quote from: Eer on 08/17/2015 06:35 PM</a>
Question for folks here:  do we know which result parameters from the Meep (or other simulation software) represent "goodness", predicting desirable performance?  High Q?  Big Pointng Vector? Or even some dynamic pattern?

I don't have the physics nor electrical engineering chops to have a clue what this all means, what's good, what's bad.

But I have some experience with some interesting technologies, including neural networks and genetic algorithms, that are really "artificial stupidity" emulators - Genetic algorithms, in particular, constitute wide scope search algorithms that are sometimes able to solve questions we don't know how to solve.  They can be used to explore large search spaces, like the field of parameters governing the size, shape, material, frequency, power and relative humidity, if you like.  Whatever you can crank into your evaluation function (which, for example, might be a Meep run).

If someone else can identify the range of interesting input parameters, and a way to compare outputs (this is better than that, for some reason you tell me, based on some output value) - well, then we could attempt to evolve solutions (even absent understanding of the empirical reason for changes in one way or another) using genetic mutation (random variation) and cross fertilization (sub-solution parameter exchange).  The result of the mutation and cross fertilization would be run through tournament-style competitions against previously known models, seeking those changes than improve the output results.

I'm not in a position to help program control files to accomplish something (like testing 2 or 3 antennae, or their shape, or position) - but I could help to figure out how to drive an automated genetic algorithm driving Meep.

If there's interest, PM me.

From what little I've been able to understand, the problem is experimental data.  The analysis that has been done on previous experiments has been sketchy due to a severe lack of data.  For instance, only one experiment has definitively verified mode shape via an infrared camera, and several experiments report one set of numbers for size and shape of the cavity but further analysis reveals problems with the numbers.  Several razor sharp minds have come up with various theories, but none have been experimentally verified.  There are theories that attenuation is good, and some where it is bad.  Theories that call for a high Q, some suggestions that lower Q may be good coupled with something else.

Bottom line, no one quite knows - and has proven - what "good" is.  Dr. Rodal's analysis reveals there are interesting asymmetries in stress tensors (I think that's what they were) - maximize asymmetry.  TheTraveller's spreadsheet is modeled after Shawyer's proprietary program and has thrust as an output, so that may be fruitful as well - maximize thrust.  There's another spreadsheet floating around as well that had McCulloch's and Notsosureofit's theories, I can't seem to find the author or link though.  Just be aware that any optimizations may be blind alleys, because we just don't know.  So, if you're itching and burning to optimize SOMETHING, then those avenues may be worthwhile.  Spreadsheets would be the handiest to experiment on, Meep is simple to run but a bit more difficult to program unless you are familiar with Lisp (Guile/Scheme implementation) and Mathematica is a commercial program (expensive unless you have access at university or work).

All the above is my own interpretation, and is probably riddled with inaccuracies, but may be a nice jumping off point for you.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/17/2015 11:44 PM
A clarification: rather than an asymmetry in the stress tensor, an asymmetry in the EM Drive: tapering from the big base to the small base.  The stress tensor is symmetric at each point.  The stresses and the forces on the big base are different from those on the small base.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/17/2015 11:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417013#msg1417013">Quote from: deltaMass on 08/17/2015 10:00 PM</a>
I am looking forward to the day when I can post

Engage!
Me too. I've got a promise to uphold.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 12:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417014#msg1417014">Quote from: Rodal on 08/17/2015 10:02 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416968#msg1416968">Quote from: SeeShells on 08/17/2015 08:20 PM</a>
...Pouring quikrete into my anti-vibration platforms. The thin plastic wasn't good enough for me so I took them apart and laying down a foundation layer of concrete to stiffen them and add some weight, but still allow the rest of the antivibration system to work. They will need to sit on a leveled platform for at least 72 hours. Oh and I also measured and weighted each one. And each one will be sitting on 5 hockey pucks of sorbothane when they are done.

Shell

I had to look that up :)

Sorbothane is the tradename for a polyether-based polyurethane material with a huge damping material property:

 tan delta = 0.5

Lots of engineering properties for Sorbothane here:  http://www.lrcltd.co.uk/products/sorbothane_c.php
Pretty neat stuff, used it before in the semi industry.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 12:16 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417022#msg1417022">Quote from: rfmwguy on 08/17/2015 10:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417016#msg1417016">Quote from: Rodal on 08/17/2015 10:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417015#msg1417015">Quote from: tchernik on 08/17/2015 10:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417013#msg1417013">Quote from: deltaMass on 08/17/2015 10:00 PM</a>
I am looking forward to the day when I can post

Engage!

I would just like to be able to follow what people are saying. The forum's content really has surpassed my ability to understand what's going on.

Are we closer to knowing if there's something real here after all or not?
I'm closer.   Waiting for rfmwguy and Shell...
Re-setup of test stand begins tomorrow with some mods, oil bath dampener, beam support wires, counterweight attachment, laser pointer remount, mirror on tripod and tripod mounted target paper. Galinstan not yet arrived. Lots of minor stuff before test a week from tomorrow...plus house guests...
I know I know so little isty bittsy tiny details. I miss the days when I'd say make it so and watch a well oiled team go to work, well kinda. ;)

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 12:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417025#msg1417025">Quote from: lmbfan on 08/17/2015 11:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416934#msg1416934">Quote from: Eer on 08/17/2015 06:35 PM</a>
Question for folks here:  do we know which result parameters from the Meep (or other simulation software) represent "goodness", predicting desirable performance?  High Q?  Big Pointng Vector? Or even some dynamic pattern?

I don't have the physics nor electrical engineering chops to have a clue what this all means, what's good, what's bad.

But I have some experience with some interesting technologies, including neural networks and genetic algorithms, that are really "artificial stupidity" emulators - Genetic algorithms, in particular, constitute wide scope search algorithms that are sometimes able to solve questions we don't know how to solve.  They can be used to explore large search spaces, like the field of parameters governing the size, shape, material, frequency, power and relative humidity, if you like.  Whatever you can crank into your evaluation function (which, for example, might be a Meep run).

If someone else can identify the range of interesting input parameters, and a way to compare outputs (this is better than that, for some reason you tell me, based on some output value) - well, then we could attempt to evolve solutions (even absent understanding of the empirical reason for changes in one way or another) using genetic mutation (random variation) and cross fertilization (sub-solution parameter exchange).  The result of the mutation and cross fertilization would be run through tournament-style competitions against previously known models, seeking those changes than improve the output results.

I'm not in a position to help program control files to accomplish something (like testing 2 or 3 antennae, or their shape, or position) - but I could help to figure out how to drive an automated genetic algorithm driving Meep.

If there's interest, PM me.

From what little I've been able to understand, the problem is experimental data.  The analysis that has been done on previous experiments has been sketchy due to a severe lack of data.  For instance, only one experiment has definitively verified mode shape via an infrared camera, and several experiments report one set of numbers for size and shape of the cavity but further analysis reveals problems with the numbers.  Several razor sharp minds have come up with various theories, but none have been experimentally verified.  There are theories that attenuation is good, and some where it is bad.  Theories that call for a high Q, some suggestions that lower Q may be good coupled with something else.

Bottom line, no one quite knows - and has proven - what "good" is.  Dr. Rodal's analysis reveals there are interesting asymmetries in stress tensors (I think that's what they were) - maximize asymmetry.  TheTraveller's spreadsheet is modeled after Shawyer's proprietary program and has thrust as an output, so that may be fruitful as well - maximize thrust.  There's another spreadsheet floating around as well that had McCulloch's and Notsosureofit's theories, I can't seem to find the author or link though.  Just be aware that any optimizations may be blind alleys, because we just don't know.  So, if you're itching and burning to optimize SOMETHING, then those avenues may be worthwhile.  Spreadsheets would be the handiest to experiment on, Meep is simple to run but a bit more difficult to program unless you are familiar with Lisp (Guile/Scheme implementation) and Mathematica is a commercial program (expensive unless you have access at university or work).

All the above is my own interpretation, and is probably riddled with inaccuracies, but may be a nice jumping off point for you.
I think you summed it up quite nicely imbfan and that's all we have. So many are wanting us to build a supersonic engine when we have barely got it to start and sometimes idle. We don't even know if it runs on swamp gas or foobiedust or a GE Microwave.

You must admit it is a great puzzle and so many highly qualified people working on it posting clues they see or great ideas. I feel it's close, very close to see solid data. A theory? Maybe a little time longer. Could it be that's why things are so quiet out there? Someone has a great theory and is backing it up with closed door EMDrive testing data? Who knows what is hidden behind closed corporate and governmental doors? All I can say this little old lady is pushing hard to make it so and I'll be as open as the doors to an all you can eat diner.

I'm looking forward to the day I can say eureka woo hoo or I've another fancy bug zapper.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/18/2015 12:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417032#msg1417032">Quote from: Rodal on 08/17/2015 11:44 PM</a>
A clarification: rather than an asymmetry in the stress tensor, an asymmetry in the EM Drive: tapering from the big base to the small base.  The stress tensor is symmetric at each point.  The stresses and the forces on the big base are different from those on the small base.
And so what of the side wall forces?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 01:04 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417023#msg1417023">Quote from: aero on 08/17/2015 11:13 PM</a>
@Dr. Rodal,

You had such a dramatic change between the 32 and 64 cycle runs that I went ahead and uploaded the csv files for the 128 cycle run. png views will be later. It is the same model as before, Yang-Shell SE 2d dipole antenna. Note that I changed the naming convention slightly. I replaced the SE and BE (big and small end indicators) with the actual row numbers, z15, z214 - and z30 is included.

https://drive.google.com/folderview?id=0B1XizxEfB23tfk81T1VtcDhjYzEyWjV6MEtBel9Fd3VQalhRWXFGU3k2VUVfZ0c4LTZxeGc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfk81T1VtcDhjYzEyWjV6MEtBel9Fd3VQalhRWXFGU3k2VUVfZ0c4LTZxeGc&usp=sharing)

aero

That made the force grow by a factor of 6,800 times the force differential between the bases for 64 cycles.  The net force difference between the bases is 0.2 microNewtons for 800 watts at this point.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 08/18/2015 01:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417052#msg1417052">Quote from: SeeShells on 08/18/2015 12:40 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417025#msg1417025">Quote from: lmbfan on 08/17/2015 11:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416934#msg1416934">Quote from: Eer on 08/17/2015 06:35 PM</a>
Question for folks here:  do we know which result parameters from the Meep (or other simulation software) represent "goodness", predicting desirable performance?  High Q?  Big Pointng Vector? Or even some dynamic pattern?

I don't have the physics nor electrical engineering chops to have a clue what this all means, what's good, what's bad.

But I have some experience with some interesting technologies, including neural networks and genetic algorithms, that are really "artificial stupidity" emulators - Genetic algorithms, in particular, constitute wide scope search algorithms that are sometimes able to solve questions we don't know how to solve.  They can be used to explore large search spaces, like the field of parameters governing the size, shape, material, frequency, power and relative humidity, if you like.  Whatever you can crank into your evaluation function (which, for example, might be a Meep run).

If someone else can identify the range of interesting input parameters, and a way to compare outputs (this is better than that, for some reason you tell me, based on some output value) - well, then we could attempt to evolve solutions (even absent understanding of the empirical reason for changes in one way or another) using genetic mutation (random variation) and cross fertilization (sub-solution parameter exchange).  The result of the mutation and cross fertilization would be run through tournament-style competitions against previously known models, seeking those changes than improve the output results.

I'm not in a position to help program control files to accomplish something (like testing 2 or 3 antennae, or their shape, or position) - but I could help to figure out how to drive an automated genetic algorithm driving Meep.

If there's interest, PM me.

From what little I've been able to understand, the problem is experimental data.  The analysis that has been done on previous experiments has been sketchy due to a severe lack of data.  For instance, only one experiment has definitively verified mode shape via an infrared camera, and several experiments report one set of numbers for size and shape of the cavity but further analysis reveals problems with the numbers.  Several razor sharp minds have come up with various theories, but none have been experimentally verified.  There are theories that attenuation is good, and some where it is bad.  Theories that call for a high Q, some suggestions that lower Q may be good coupled with something else.

Bottom line, no one quite knows - and has proven - what "good" is.  Dr. Rodal's analysis reveals there are interesting asymmetries in stress tensors (I think that's what they were) - maximize asymmetry.  TheTraveller's spreadsheet is modeled after Shawyer's proprietary program and has thrust as an output, so that may be fruitful as well - maximize thrust.  There's another spreadsheet floating around as well that had McCulloch's and Notsosureofit's theories, I can't seem to find the author or link though.  Just be aware that any optimizations may be blind alleys, because we just don't know.  So, if you're itching and burning to optimize SOMETHING, then those avenues may be worthwhile.  Spreadsheets would be the handiest to experiment on, Meep is simple to run but a bit more difficult to program unless you are familiar with Lisp (Guile/Scheme implementation) and Mathematica is a commercial program (expensive unless you have access at university or work).

All the above is my own interpretation, and is probably riddled with inaccuracies, but may be a nice jumping off point for you.
I think you summed it up quite nicely imbfan and that's all we have. So many are wanting us to build a supersonic engine when we have barely got it to start and sometimes idle. We don't even know if it runs on swamp gas or foobiedust or a GE Microwave.

You must admit it is a great puzzle and so many highly qualified people working on it posting clues they see or great ideas. I feel it's close, very close to see solid data. A theory? Maybe a little time longer. Could it be that's why things are so quiet out there? Someone has a great theory and is backing it up with closed door EMDrive testing data? Who knows what is hidden behind closed corporate and governmental doors? All I can say this little old lady is pushing hard to make it so and I'll be as open as the doors to an all you can eat diner.

I'm looking forward to the day I can say eureka woo hoo or I've another fancy bug zapper.

Shell

Thank you both - that's what I wondered - sounds like more experimental data is necessary to even know what changes in the analytical data are meaningful. 

Well, the offer stands if / when anyone thinks some exploration towards optimization would be worth while.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 01:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417058#msg1417058">Quote from: deltaMass on 08/18/2015 12:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417032#msg1417032">Quote from: Rodal on 08/17/2015 11:44 PM</a>
A clarification: rather than an asymmetry in the stress tensor, an asymmetry in the EM Drive: tapering from the big base to the small base.  The stress tensor is symmetric at each point.  The stresses and the forces on the big base are different from those on the small base.
And so what of the side wall forces?
Think about them.  That's why I think it is better to put the antenna RF feed near the big base.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/18/2015 01:31 AM

Quote
Think about them.  That's why it is better to put the antenna RF feed near the big base.

Because at least a portion of the pressure on the sidewalls amounts to 'thrust' in the forward direction?  Because they are angled and not straight?

I keep thinking about these rapidly forming and decaying...shapes or modes...in the various nifty pictures.  Seems almost like they provide a 'punch' in the right direction but decay so fast CoE doesn't have time to properly kick in.  Which is flat out ridiculous. 

I also keep thinking this forming/decaying real fast bit accounts for a hefty chunk of the out of whack experimental results: I suspect at some point the whole cycle will become so unstable it collapses and needs to be reset (but if so, how long a reset period?)  More, the overall collapse is not uniform, so same experimental model, same conditions, inputs, and whatnot could collapse at different times. 

(hm...maybe the best testers of this device would be twelve year old video game players?  honed reflexes and all?)

Getting a handle on the thermal end of things might stave off the collapse for a while, but doesn't address the inherit underlying instability.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 01:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417068#msg1417068">Quote from: ThinkerX on 08/18/2015 01:31 AM</a>
Quote
Think about them.  That's why it is better to put the antenna RF feed near the big base.

Because at least a portion of the pressure on the sidewalls amounts to 'thrust' in the forward direction?  Because they are angled and not straight?

I keep thinking about these rapidly forming and decaying...shapes or modes...in the various nifty pictures.  Seems almost like they provide a 'punch' in the right direction but decay so fast CoE doesn't have time to properly kick in.  Which is flat out ridiculous. 

I also keep thinking this forming/decaying real fast bit accounts for a hefty chunk of the out of whack experimental results: I suspect at some point the whole cycle will become so unstable it collapses and needs to be reset (but if so, how long a reset period?)  More, the overall collapse is not uniform, so same experimental model, same conditions, inputs, and whatnot could collapse at different times. 

(hm...maybe the best testers of this device would be twelve year old video game players?  honed reflexes and all?)

Getting a handle on the thermal end of things might stave off the collapse for a while, but doesn't address the inherit underlying instability.

Many instabilities in real systems resolve themselves into limit cycles.  Maybe an "Electromagnetic Dean Drive" ?

Have to wait for more experiments:  rfmwguy, Shell, TheTraveller...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 02:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417068#msg1417068">Quote from: ThinkerX on 08/18/2015 01:31 AM</a>
Quote
Think about them.  That's why it is better to put the antenna RF feed near the big base.

Because at least a portion of the pressure on the sidewalls amounts to 'thrust' in the forward direction?  Because they are angled and not straight?

I keep thinking about these rapidly forming and decaying...shapes or modes...in the various nifty pictures.  Seems almost like they provide a 'punch' in the right direction but decay so fast CoE doesn't have time to properly kick in.  Which is flat out ridiculous. 

I also keep thinking this forming/decaying real fast bit accounts for a hefty chunk of the out of whack experimental results: I suspect at some point the whole cycle will become so unstable it collapses and needs to be reset (but if so, how long a reset period?)  More, the overall collapse is not uniform, so same experimental model, same conditions, inputs, and whatnot could collapse at different times. 

(hm...maybe the best testers of this device would be twelve year old video game players?  honed reflexes and all?)

Getting a handle on the thermal end of things might stave off the collapse for a while, but doesn't address the inherit underlying instability.
If it's mode stability that truly makes this thing work then it can be achieved in the wht waveguide using standard technologies and in the frustum.
http://journals.aps.org/prstab/pdf/10.1103/PhysRevSTAB.13.022004

Right now we simply don't know if it's the ordered instability of the mode switching creating hammering stress tensors into the ends or walls or what but it's going to be an interesting ride to find out.

Also you might want to think about how the decay of evanescent waves could impart the cycling stresses into the ends and walls while decaying. I wonder about this decaying wave function still.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/18/2015 03:35 AM

Quote
Also you might want to think about how the decay of evanescent waves could impart the cycling stresses into the ends and walls while decaying. I wonder about this decaying wave function still.

Been thinking a bit about this as well: Without an extra 'kick' of some sort, putting the EM source in the base isn't going to result in net thrust - I think.  So, somewhere between formation and impact, that 'kick' is added.  I see three possibilities at the moment:

1 - evanescent waves as you have pointed out, known (?) to be present, and also known (?) to be capable of transferring momentum.

2 - a 'bouncing photon' scheme similar to that of David Bae (which is why I kept pestering Delta Mass about this.  I suspect a clue or key to this riddle is to be found in Bae's work, and have thought so for months).

3 - Mulletron's 'enlarged photons' - photons that gain a lot more mass because they are inside a tapered waveguide, and hence impact with more 'punch.'  This makes photons downright weird.

Or maybe it's some combination of the above. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/18/2015 03:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417068#msg1417068">Quote from: ThinkerX on 08/18/2015 01:31 AM</a>
Quote
Think about them.  That's why it is better to put the antenna RF feed near the big base.

Because at least a portion of the pressure on the sidewalls amounts to 'thrust' in the forward direction?  Because they are angled and not straight?

I keep thinking about these rapidly forming and decaying...shapes or modes...in the various nifty pictures.  Seems almost like they provide a 'punch' in the right direction but decay so fast CoE doesn't have time to properly kick in.  Which is flat out ridiculous. 

I also keep thinking this forming/decaying real fast bit accounts for a hefty chunk of the out of whack experimental results: I suspect at some point the whole cycle will become so unstable it collapses and needs to be reset (but if so, how long a reset period?)  More, the overall collapse is not uniform, so same experimental model, same conditions, inputs, and whatnot could collapse at different times. 

(hm...maybe the best testers of this device would be twelve year old video game players?  honed reflexes and all?)

Getting a handle on the thermal end of things might stave off the collapse for a while, but doesn't address the inherit underlying instability.

If the collapse takes place at multiples of 187.5 and can maintain energy by shifting to a higher frequency I'm going to go hide in a cave for a bit.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 04:53 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417059#msg1417059">Quote from: Rodal on 08/18/2015 01:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417023#msg1417023">Quote from: aero on 08/17/2015 11:13 PM</a>
@Dr. Rodal,

You had such a dramatic change between the 32 and 64 cycle runs that I went ahead and uploaded the csv files for the 128 cycle run. png views will be later. It is the same model as before, Yang-Shell SE 2d dipole antenna. Note that I changed the naming convention slightly. I replaced the SE and BE (big and small end indicators) with the actual row numbers, z15, z214 - and z30 is included.

https://drive.google.com/folderview?id=0B1XizxEfB23tfk81T1VtcDhjYzEyWjV6MEtBel9Fd3VQalhRWXFGU3k2VUVfZ0c4LTZxeGc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfk81T1VtcDhjYzEyWjV6MEtBel9Fd3VQalhRWXFGU3k2VUVfZ0c4LTZxeGc&usp=sharing)

aero

That made the force grow by a factor of 6,800 times the force differential between the bases for 64 cycles.  The net force difference between the bases is 0.2 microNewtons for 800 watts at this point.
Wow, even with mode collapsing we're kicking up the force factor?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 04:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417110#msg1417110">Quote from: SteveD on 08/18/2015 03:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417068#msg1417068">Quote from: ThinkerX on 08/18/2015 01:31 AM</a>
Quote
Think about them.  That's why it is better to put the antenna RF feed near the big base.



If the collapse takes place at multiples of 187.5 and can maintain energy by shifting to a higher frequency I'm going to go hide in a cave for a bit.

I had to burst out laughing, I read and remember way too much. lol
http://www.forbes.com/sites/paulrodgers/2015/04/02/message-from-the-aliens-187-5/

Been a long day... thanks for the smile.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/18/2015 07:00 AM
DeltaMass at reply 669 reminds me of something that's been bugging me for a few days now.

If I recall correctly, Dr. Rodal is calculating net forces on the end plates, due to the complexity of the sidewall calculations. If that's a mistaken impression, let me know and I can stop worrying.

If that's right though, net force on the ends tells us very little. If we had a frustum shaped balloon, there would be net air pressure towards the big end on that calculation. Further, one of the criticisms of Shawyers explanation was that he had mis-handled the contribution from the side walls which should have made the net calculated force zero.

Bottom line is that we need sidewall forces to draw any conclusions at all on total force.

Please don't anyone jump to the conclusion that I'm in any way belittling what's been done with MEEP and post-processing - I think it's a fantastic effort, and looks to be close to being able to answer the central question of force generation. But it does need that last step to be taken.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/18/2015 08:53 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417097#msg1417097">Quote from: SeeShells on 08/18/2015 02:44 AM</a>

If it's mode stability that truly makes this thing work then it can be achieved in the wht waveguide using standard technologies and in the frustum.
http://journals.aps.org/prstab/pdf/10.1103/PhysRevSTAB.13.022004

Right now we simply don't know if it's the ordered instability of the mode switching creating hammering stress tensors into the ends or walls or what but it's going to be an interesting ride to find out.

Also you might want to think about how the decay of evanescent waves could impart the cycling stresses into the ends and walls while decaying. I wonder about this decaying wave function still.

Shell,
is there any experimental setup you can think of that would help to understand if the forces originate from hammering the end plates or whether they come to life through evanescent waves along the sidewalls?

How the experiment(s) could be modified to support/disapprove the several theories is most likely the next phase, once the initial tests do provide a significant force signal.


On a side note:
Because the waveguide openings in the sidewalls seriously disrupt the wave patterns, I'm wondering if there exist a microwave equivalent of what the spy mirror glass is for visual light.

Are there materials that are more microwave reflective on one side then the other, effectively allowing them to pass from one side, but not from the other?
Such a material would solve the large cuts in the sidewalls (and their disruptive influence on the resonance patterns), and allow the wave guide to be fed through the large bottom plate...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 11:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417151#msg1417151">Quote from: RERT on 08/18/2015 07:00 AM</a>
DeltaMass at reply 669 reminds me of something that's been bugging me for a few days now.

If I recall correctly, Dr. Rodal is calculating net forces on the end plates, due to the complexity of the sidewall calculations. If that's a mistaken impression, let me know and I can stop worrying.

If that's right though, net force on the ends tells us very little. If we had a frustum shaped balloon, there would be net air pressure towards the big end on that calculation. Further, one of the criticisms of Shawyers explanation was that he had mis-handled the contribution from the side walls which should have made the net calculated force zero.

Bottom line is that we need sidewall forces to draw any conclusions at all on total force.

Please don't anyone jump to the conclusion that I'm in any way belittling what's been done with MEEP and post-processing - I think it's a fantastic effort, and looks to be close to being able to answer the central question of force generation. But it does need that last step to be taken.

This has been discussed in several messages prior to DeltaMass question.  Since it has been addressed in prior messages, I'll use the Socratic method as an answer here, since best understanding comes from individual thinking.

<<Bottom line is that we need sidewall forces to draw any conclusions at all on total force>>  No, that's not necessarily true when one knows more conditions.  Some conclusions can be drawn for cases where there is more information.  For example, someone could say that in general, for a quadrilateral one has to know the length of all four sides to know the area of the quadrilateral.  That's not true for a rectangle: just knowing two sides is enough in that case. (Since you have extra information: you know the internal angles of a rectangle).

Think about the following:  draw the truncated cone.  Perform a vector force diagram.  What is the nature of the stress tensor on the conical side walls for TM modes? how about for TE modes? Is there a difference between these two?
Is the electromagnetic stress tensor always compressive?  What governs the sign of the electromagnetic stress tensor components?  Is the comparison to a truncated-cone-shaped-balloon under internal pressure appropriate?
What assumptions about this problem are correct? Which ones are incorrect?

Have you used all the information available?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/18/2015 12:52 PM
Seems to me that from a force generation point of view, on condition Yang's calculations are correct ofc, the side walls are as important as getting the right TE mode, both yielding about the same amount of force ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 03:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417163#msg1417163">Quote from: Flyby on 08/18/2015 08:53 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417097#msg1417097">Quote from: SeeShells on 08/18/2015 02:44 AM</a>

If it's mode stability that truly makes this thing work then it can be achieved in the wht waveguide using standard technologies and in the frustum.
http://journals.aps.org/prstab/pdf/10.1103/PhysRevSTAB.13.022004

Right now we simply don't know if it's the ordered instability of the mode switching creating hammering stress tensors into the ends or walls or what but it's going to be an interesting ride to find out.

Also you might want to think about how the decay of evanescent waves could impart the cycling stresses into the ends and walls while decaying. I wonder about this decaying wave function still.
***************************************
Shell,
Q: is there any experimental setup you can think of that would help to understand if the forces originate from hammering the end plates or whether they come to life through evanescent waves along the sidewalls?
*****
A: I'm thinking if it is evanescent waves I should see a ratio as you increase the distance of the small plate within the cavity and have been researching. (interesting read) http://spie.org/x16896.xml
One reason I wanted the gold electroplating to be around 5um on the small plate to allow evanescent wave tunneling using schrodinger's equations.   
*****
Q: How the experiment(s) could be modified to support/disapprove the several theories is most likely the next phase, once the initial tests do provide a significant force signal.
*****
A: And I'll welcome all inputs.
*****
On a side note:
Q: Because the waveguide openings in the sidewalls seriously disrupt the wave patterns, I'm wondering if there exist a microwave equivalent of what the spy mirror glass is for visual light.
Are there materials that are more microwave reflective on one side then the other, effectively allowing them to pass from one side, but not from the other?
Such a material would solve the large cuts in the sidewalls (and their disruptive influence on the resonance patterns), and allow the wave guide to be fed through the large bottom plate...
******
A: I've not researched that yet to any extreme. On my bucket list. ;) I think inserting the wave forms symmetrically opposed into the cavity is so much better than Tajmar & Fiedler's single magnetron angled approach.  ... Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: venir on 08/18/2015 03:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417180#msg1417180">Quote from: TheTraveller on 08/18/2015 11:40 AM</a>
**Op-Ed: EMDrive ‘does work’, but Spectator Science disagrees**

http://www.digitaljournal.com/science/op-ed-emdrive-does-work-but-spectator-science-disagrees/article/441374

Must send him a link to the "E Files":

https://drive.google.com/folderview?id=0B7kgKijo-p0ifnFrZ2V1UmZEY25FXzNrX0hjNXJmQXR5YzRnaVBqcTdMZUhxcjVkMUUtaXc&usp=sharing

I know that this is an Op-Ed piece but man does it strike me as being very poorly written. He barely touches on the subject of the article and it is really hard to follow his train of thought. His point seems to be, some people have claimed to have found some results from experiments so we should blindly embrace it without questioning the process.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/18/2015 04:04 PM
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 04:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.
Why are we here? Perchance to dream.
I'm reminded of a poem I had on my bedroom wall as a young girl.

High Flight

John Gillespie Magee, Jr
Oh! I have slipped the surly bonds of earth,
And danced the skies on laughter-silvered wings;
Sunward I've climbed, and joined the tumbling mirth
Of sun-split clouds, --and done a hundred things
You have not dreamed of --Wheeled and soared and swung
High in the sunlit silence. Hov'ring there
I've chased the shouting wind along, and flung
My eager craft through footless halls of air...
Up, up the long, delirious, burning blue
I've topped the wind-swept heights with easy grace
Where never lark or even eagle flew --
And, while with silent lifting mind I've trod
The high untrespassed sanctity of space,
Put out my hand, and touched the face of God.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/18/2015 04:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417196#msg1417196">Quote from: Rodal on 08/18/2015 01:53 PM</a>
Hydrogen sulfide — the compound responsible for the smell of rotten eggs — conducts electricity with zero resistance at a record high temperature of 203 kelvin (–70 °C), reports a paper published today in Nature.



some lab or uni is reporting the production of actual stanene (think graphene but made of tin) samples. these are topological insulators whose very edge passes electrons along with no resistance.

EDIT: meant to mention it does this at room temperature. allegedly.

EDIT 2:  http://phys.org/news/2015-08-team-sample-stanene.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 05:11 PM
http://epublications.marquette.edu/cgi/viewcontent.cgi?article=1028&context=theses_open

I'm about a quarter of the way through and my head is heavy, good read, good ideas to think about. I think I'll do something primitive for a bit, like pound some nails in wood...after a hot tub.

BBL 

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 05:54 PM
Continuing from http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443

we present the forces at the small and the big base for Yang/Shell 6 degree truncated cone excited in mode TE012 at 2.45 GHz with a parallel 2 dipole antenna located near the small end, for 3 times after turning the RF feed on: 0.013 microseconds, 0.026 microseconds, and 0.052 microseconds.  These are results from Meep runs by aero, that have been post-processed using a code I wrote using Wolfram Mathematica.

Notice that the rate of growth per unit time is diminishing with time:

Time           Normalized Force/Time Linear Slope                     Exponential         Force
(μsec)                                                                                   magnification   (10^(-12) Newton/43 watt)
  0.013       (-0.000094878)/(-0.00365708) t = 0.02594 t      0.0220981 t               -0.00365708
  0.026       (-0.040004)/( -1.99742) t = 0.02003 t                 0.0177789 t                -1.99742
  0.052       (-102.715)/(-10496.2) t = 0.00979 t                    0.00992341 t      -10496.2

At this rate, the force differential will be in the milliNewton range for 800 watts after approximately 0.1 to 0.5 μsec after the RF feed is turned on.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/18/2015 06:05 PM
Dr. Rodal -

Gosh, this might be quite fun!

Since you've shown meep runs with compressive force at one end and tensile force at the other, I think it is far from obvious what the answer is. Yes, if the fields are axially symmetric, one could deduce that the force on the sidewalls is purely axial, but that doesn't help much, and in any case other meep runs on the end faces have shown a lack of such symmetry likely to be extended to the side walls by continuity.

Dearie me I feel such a silly! Perhaps you could enlighten me (and perhaps DeltaMass, who didn't know the answer five minutes ago, though I'm sure he's clever enough to figure it out for himself!) - I'm sure that actually it might be a little quicker to simply articulate the argument, rather than ask so many question which I confess I find rather dazzlingly brilliant!

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 06:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417281#msg1417281">Quote from: RERT on 08/18/2015 06:05 PM</a>
Dr. Rodal -

Gosh, this might be quite fun!

Since you've shown meep runs with compressive force at one end and tensile force at the other, I think it is far from obvious what the answer is. Yes, if the fields are axially symmetric, one could deduce that the force on the sidewalls is purely axial, but that doesn't help much, and in any case other meep runs on the end faces have shown a lack of such symmetry likely to be extended to the side walls by continuity.

Dearie me I feel such a silly! Perhaps you could enlighten me (and perhaps DeltaMass, who didn't know the answer five minutes ago, though I'm sure he's clever enough to figure it out for himself!) - I'm sure that actually it might be a little quicker to simply articulate the argument, rather than ask so many question which I confess I find rather dazzlingly brilliant!

R.
Concerning DeltaMass, he has asked questions such as: what system can self-accelerate in space and be consistent with General Relativity and conservation of momentum and conservation of energy?  So, deltaMass is not adverse to using the Socratic method.

As the Mathematician Polya wrote in his classic book "How to solve it", ask yourself again: 

Have you used all the information available?

What is the nature of the stress tensor on the conical side walls for TM modes? how about for TE modes? Is there a difference between these two?  (We are not talking about the force being purely axial, but rather what is the difference between the stress tensor in TE and TM modes) What governs the sign of the electromagnetic stress tensor components?   What assumptions about this problem are correct? Which ones are incorrect?

These last results for Yang/Shell are for TE mode with the antenna near the small base.
Take another look at the results for the antenna at near the big base for TM modes.  How can that be reacted by the conical walls (at a known angle)?  What difference does antenna location make for TM modes?  What difference will it make for TE modes?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/18/2015 07:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417275#msg1417275">Quote from: Rodal on 08/18/2015 05:54 PM</a>
Continuing from http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443

we present the forces at the small and the big base for Yang/Shell 6 degree truncated cone excited in mode TE012 at 2.45 GHz with a parallel 2 dipole antenna located near the small end, for 3 times after turning the RF feed on: 0.013 microseconds, 0.026 microseconds, and 0.052 microseconds.  These are results from Meep runs by aero, that have been post-processed using a code I wrote using Wolfram Mathematica.

Notice that the rate of growth per unit time is diminishing with time:

Time           Normalized Force/Time Linear Slope                     Exponential         Force
(μsec)                                                                                   magnification   (10^(-12) Newton/43 watt)
  0.013       (-0.000094878)/(-0.00365708) t = 0.02594 t      0.0220981 t               -0.00365708
  0.026       (-0.040004)/( -1.99742) t = 0.02003 t                 0.0177789 t                -1.99742
  0.052       (-102.715)/(-10496.2) t = 0.00979 t                    0.00992341 t      -10496.2

At this rate, the force differential will be in the milliNewton range for 800 watts after approximately 0.1 to 0.5 μsec after the RF feed is turned on.

So it's creating thrust in pulses that are longer than the meep run?  I wonder if the turn on effect might indicate that it takes a certain number of pulses for the system to stabilize at max thrust.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/18/2015 07:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417125#msg1417125">Quote from: SeeShells on 08/18/2015 04:59 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417110#msg1417110">Quote from: SteveD on 08/18/2015 03:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417068#msg1417068">Quote from: ThinkerX on 08/18/2015 01:31 AM</a>
Quote
Think about them.  That's why it is better to put the antenna RF feed near the big base.



If the collapse takes place at multiples of 187.5 and can maintain energy by shifting to a higher frequency I'm going to go hide in a cave for a bit.

I had to burst out laughing, I read and remember way too much. lol
http://www.forbes.com/sites/paulrodgers/2015/04/02/message-from-the-aliens-187-5/

Been a long day... thanks for the smile.

Shell

Oh, man.  Thanks for the link, Shell.  That one went right over my head.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 07:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417303#msg1417303">Quote from: SteveD on 08/18/2015 07:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417275#msg1417275">Quote from: Rodal on 08/18/2015 05:54 PM</a>
Continuing from http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416443#msg1416443

we present the forces at the small and the big base for Yang/Shell 6 degree truncated cone excited in mode TE012 at 2.45 GHz with a parallel 2 dipole antenna located near the small end, for 3 times after turning the RF feed on: 0.013 microseconds, 0.026 microseconds, and 0.052 microseconds.  These are results from Meep runs by aero, that have been post-processed using a code I wrote using Wolfram Mathematica.

Notice that the rate of growth per unit time is diminishing with time:

Time           Normalized Force/Time Linear Slope                     Exponential         Force
(μsec)                                                                                   magnification   (10^(-12) Newton/43 watt)
  0.013       (-0.000094878)/(-0.00365708) t = 0.02594 t      0.0220981 t               -0.00365708
  0.026       (-0.040004)/( -1.99742) t = 0.02003 t                 0.0177789 t                -1.99742
  0.052       (-102.715)/(-10496.2) t = 0.00979 t                    0.00992341 t      -10496.2

At this rate, the force differential will be in the milliNewton range for 800 watts after approximately 0.1 to 0.5 μsec after the RF feed is turned on.

So it's creating thrust in pulses that are longer than the meep run?  I wonder if the turn on effect might indicate that it takes a certain number of pulses for the system to stabilize at max thrust.

No, aero run Meep in 3 separate runs, from the time that the RF feed was turned on, for run times ( in real time ) of

Aero              Total Real Time         
Run #            (μsec)                                                                                   
1                     0.013     
2                     0.026     
3                     0.052 

Total run times are as indicated in microseconds.  RF feed is on continuously, as an electromagnetic wave with nominal frequency 2.45 GHz for the amount of time indicated. No pulses. 

All that can be processed is based on what aero decided to run and what aero decided to output based on each run. 

The unit of time in the graphs shown is only 40 picoseconds.

One cycle of force (or stress) at 4.8 GHz is 208.33 picoseconds, or 5.1 time units.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/18/2015 07:53 PM
Have to go out for a bit but what I find interesting in the wave forms showing the phase shifting of the blue large base. When they phase match the canceling stress between the two should at max.

This makes sense. The total force stress decreases as the phases of the stresses become equal in phase. What is interesting is when the large base stress phase passes TDC on the small which it is looking like it's doing.

Does it seems likely that the small base force will start to increase again as the stresses phase shift progresses?

http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1057452
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1057456


Edit... Red is Blue and Blue is Red.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/18/2015 08:23 PM
The new version of the baby-EmDrive, 3D-printed and silver-plated has been received by the folks at hackaday.io (https://hackaday.io/project/5596-em-drive/log/23696-silver-cavity-arrived)!

Db = 29.64 mm
Ds = 16.12 mm
L = 21.87mm
+ cylindrical neck for tuning = 5mm

Antenna placement near the small base = 5.5 mm below cylindrical neck

Excitation frequency between 24 an 25 GHz.

Several modes predicted and very close from each others (TE013, TE114 and TM113) according to TT's spreadsheet.

Flat ends plates to begin with, but spherical ends are doable too.

(880731439909923274.jpg) (https://hackaday.io/project/5596-em-drive/log/23696-silver-cavity-arrived)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/18/2015 08:48 PM
Good to see (and to know) that the silver plating solved some of the layering/pitting issues that usually come with 3Dprinting...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/18/2015 09:20 PM
I have modelled the Yang-Shell frustum with the antenna located near the big end. I have made 3 meep runs, one each for 32, 64 and 128 complete cycles with the final 14 time slices saved, a slice each one-tenth cycle. I have generated and uploaded the csv file data sets for Dr. Rodal's attention.

First, the 32 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing)

Second, the 64 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing)

And lastly, the 128 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing)

My apologises to SeeShells, as the png-view files are not yet available. We are working on it. I note that the Quality factor calculated by Harminv for this antenna configuration puts it well into the superconducting cavity arena. I am anxious to see the png views myself because if my thought that evanescent waves actually accomplish their superluminal behaviour via a form of tunnelling, then with this high Q model, there should be enough energy stored within the cavity to trigger tunnelling through the bases. And preferentially through the base where the EM waves are more energetic. But meep likely wouldn't calculate anything like tunneling and there doesn't seem to be any indication in the csv files.

Note to Dr. Rodal - The Google drive upload process was a little wonky on the 32 and 64 cycle data. I think the data is ok, but if there are missing files don't be surprised but do let me know.

aero

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 10:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417335#msg1417335">Quote from: aero on 08/18/2015 09:20 PM</a>
I have modelled the Yang-Shell frustum with the antenna located near the big end. I have made 3 meep runs, one each for 32, 64 and 128 complete cycles with the final 14 time slices saved, a slice each one-tenth cycle. I have generated and uploaded the csv file data sets for Dr. Rodal's attention.

First, the 32 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing)

Second, the 64 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing)

And lastly, the 128 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing)

My apologises to SeeShells, as the png-view files are not yet available. We are working on it. I note that the Quality factor calculated by Harminv for this antenna configuration puts it well into the superconducting cavity arena. I am anxious to see the png views myself because if my thought that evanescent waves actually accomplish their superluminal behaviour via a form of tunnelling, then with this high Q model, there should be enough energy stored within the cavity to trigger tunnelling through the bases. And preferentially through the base where the EM waves are more energetic. But meep likely wouldn't calculate anything like tunneling and there doesn't seem to be any indication in the csv files.

Note to Dr. Rodal - The Google drive upload process was a little wonky on the 32 and 64 cycle data. I think the data is ok, but if there are missing files don't be surprised but do let me know.

aero

Importing from this directory, for the 128 cycle folder:

\\Shell-128-BE-2d-loop-ant \\ csv-directory \\

gives exactly the same results as for the previous run with the antenna near the small base.

The plot below verifies that this is the case: this folder contains the same files with the antenna at the small end

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 10:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417335#msg1417335">Quote from: aero on 08/18/2015 09:20 PM</a>
I have modelled the Yang-Shell frustum with the antenna located near the big end. I have made 3 meep runs, one each for 32, 64 and 128 complete cycles with the final 14 time slices saved, a slice each one-tenth cycle. I have generated and uploaded the csv file data sets for Dr. Rodal's attention.

First, the 32 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing)
...

Note to Dr. Rodal - The Google drive upload process was a little wonky on the 32 and 64 cycle data. I think the data is ok, but if there are missing files don't be surprised but do let me know.

aero



Ditto for Importing from this directory, for the 64 cycle folder:

\\Shell-64-BE-2d-loop-ant \\ csv-directory \\

gives exactly the same results as for the previous run with the antenna near the small base.

The plot below verifies that this is the case: this folder contains the same files with the antenna at the small end

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/18/2015 10:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417335#msg1417335">Quote from: aero on 08/18/2015 09:20 PM</a>
I have modelled the Yang-Shell frustum with the antenna located near the big end. I have made 3 meep runs, one each for 32, 64 and 128 complete cycles with the final 14 time slices saved, a slice each one-tenth cycle. I have generated and uploaded the csv file data sets for Dr. Rodal's attention.

First, the 32 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing)
...

Note to Dr. Rodal - The Google drive upload process was a little wonky on the 32 and 64 cycle data. I think the data is ok, but if there are missing files don't be surprised but do let me know.

aero



Ditto for Importing from this directory, for the 32 cycle folder:

\\Shell-32-BE-2d-loop-ant \\ csv-directory \\

gives exactly the same results as for the previous run with the antenna near the small base.

The plot below verifies that this is the case: this folder contains the same files with the antenna at the small end

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/18/2015 10:44 PM
Well that sucks.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/18/2015 11:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417328#msg1417328">Quote from: Flyby on 08/18/2015 08:48 PM</a>
Good to see (and to know) that the silver plating solved some of the layering/pitting issues that usually come with 3Dprinting...
I presume that small cavity was cast using 3D printed model in wax, next the plaster mold was created, then molten Sterling silver was poured into the mold and finally - polished.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/19/2015 12:10 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417362#msg1417362">Quote from: Rodal on 08/18/2015 10:51 PM</a>
Everything is the same.  I also checked the Poynting vector plots, the stress plots, and the force plots.  All identical to the antenna near the small base.  I also have plots of the fields in other directions showing the antenna is at the small base.

 :-[  Yea - the log files confirm the antenna was the same. Re-checking resonance now.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/19/2015 12:46 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417360#msg1417360">Quote from: aero on 08/18/2015 10:44 PM</a>
Well that sucks.
As we say out West... Yeeiup.

From what I understand meep stops at the surface boundary of the walls with Maxwell. A Senior Physics student majoring in high energy physics mentioned it to me about the limits of meep, never verified it though, although it makes sense. 

Calling //ElizabethGreen. What did you find out when you said you thought you were seeing evanescent waves out the top of the frustum and were waiting for some equipment to arrive and check. Any news yet?

Ok, poo on the Yang-Shell 6 degree sides. It means I'm modifying and running with the Crazy-Eddie-Drive  build with the ceramic plates. So I need to push a little harder.

Shell

PS: The new anti-vibration platforms seem to be working, still need to let it set another day.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/19/2015 01:03 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.

I know I'm a broken record, but IMHO there are many more uncontrollable factors in low earth orbit than in the lab, considering the minscule power available for the thruster on a cubesat.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/19/2015 01:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417322#msg1417322">Quote from: flux_capacitor on 08/18/2015 08:23 PM</a>
The new version of the baby-EmDrive, 3D-printed and silver-plated has been received by the folks at hackaday.io (https://hackaday.io/project/5596-em-drive/log/23696-silver-cavity-arrived)!

Db = 29.64 mm
Ds = 16.12 mm
L = 21.87mm
+ cylindrical neck for tuning = 5mm

Antenna placement near the small base = 5.5 mm below cylindrical neck

Excitation frequency between 24 an 25 GHz.

Several modes predicted and very close from each others (TE013, TE114 and TM113) according to TT's spreadsheet.

Flat ends plates to begin with, but spherical ends are doable too.

(880731439909923274.jpg) (https://hackaday.io/project/5596-em-drive/log/23696-silver-cavity-arrived)

Shot glass to the stars!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/19/2015 01:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417393#msg1417393">Quote from: SeeShells on 08/19/2015 12:46 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417360#msg1417360">Quote from: aero on 08/18/2015 10:44 PM</a>
Well that sucks.
...From what I understand meep stops at the surface boundary of the walls with Maxwell. A Senior Physics student majoring in high energy physics mentioned it to me about the limits of meep, never verified it though, although it makes sense.  ...
The reason why Meep is an open source code is for users to write their own code to introduce whatever equations they want to use for the walls, etc.  Many papers I have seen where Meep is used, it is not used as a black box but the researchers write the new parts of the code necessary for their research.  Similarly, Wolfram Mathematica out of the box cannot post-process Meep data to calculate the Poynting vector, stress tensor, etc.  I had to write code in Wolfram Mathematica to be able to ouput the stress, I had to write code to make the vector plots, etc..

Therefore open codes that enable the user to write their own code do not have limitations, as anything that can be analyzed certainly can be coded (as proved by von Neumann).  If there is an equation that expresses quantum tunneling as a function of the wall thickness, material, and the surrounding electromagnetic fields, that equation can in principle be coded into Meep (or into Wolfram Mathematica, or into C).  At that point, the question is rather what code is more expedient to program.  Rather the statement has to be qualified to read instead "out of the box, Meep..."

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/19/2015 02:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417405#msg1417405">Quote from: Rodal on 08/19/2015 01:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417393#msg1417393">Quote from: SeeShells on 08/19/2015 12:46 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417360#msg1417360">Quote from: aero on 08/18/2015 10:44 PM</a>
Well that sucks.
...From what I understand meep stops at the surface boundary of the walls with Maxwell. A Senior Physics student majoring in high energy physics mentioned it to me about the limits of meep, never verified it though, although it makes sense.  ...
The reason why Meep is an open source code is for users to write their own code to introduce whatever equations they want to use for the walls, etc.  Many papers I have seen where Meep is used, it is not used as a black box but the researchers write the new parts of the code necessary for their research.  Similarly, Wolfram Mathematica out of the box cannot post-process Meep data to calculate the Poynting vector, stress tensor, etc.  I had to write code in Wolfram Mathematica to be able to ouput the stress, I had to write code to make the vector plots, etc..

Therefore open codes that enable the user to write their own code do not have limitations, as anything that can be analyzed certainly can be coded (as proved by von Neumann).  If there is an equation that expresses quantum tunneling as a function of the wall thickness, material, and the surrounding electromagnetic fields, that equation can in principle be coded into Meep (or into Wolfram Mathematica, or into C).  At that point, the question is rather what code is more expedient to program.  Rather the statement has to be qualified to read instead "out of the box, Meep..."
Stand corrected so I'll make it so... "out of the box, Meep..."

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/19/2015 02:23 AM
That is exactly right, just about. (because I don't know any better, but maybe ...)

Here is a nice paper on electron tunnelling. I have found those same equations (same form) describing evanescent waves propagating through a wave guide below cutoff frequency. I like this paper because ISU is my school.

http://tuttle.merc.iastate.edu/ee439/topics/tunneling.pdf (http://tuttle.merc.iastate.edu/ee439/topics/tunneling.pdf)

I have made the effort to code the final equation up in Maxima and got an answer that I didn't like. Maybe an understanding of the physics, barriers and the cavity energies would help to get an answer with assurance, an understanding that is beyond me. It would be nice to know if Q needs to be greater than 1050, because such an answer would rule out tunnelling based on current knowledge.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/19/2015 02:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417377#msg1417377">Quote from: Rodal on 08/18/2015 11:48 PM</a>
Here is an EM Drive test that we can all do in a bathtub (no, a hot tub is not required) without having to worry about dangerous magnetrons, or getting electrocuted.

EM Drive 2D simulation by Grzegorz Maj  using water as a medium (not the first time that a physics problems with waves has been analyzed using water as an analog) "the Water Drive"

Droplets falling on the Water Drive are used to create waves inside the Water Drive.

Notice that it moves towards the big base.
 

https://www.youtube.com/watch?t=77&v=VEacNk2uFaM

Suggestion: try other shapes (squares, circles, trombone, etc.).
That's most unscientific. The intrinsic x-y momentum of the driving source is not examined and not controlled for. The least one could do to be honest here is to flip the shape around so that now the small end faces right.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/19/2015 02:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417397#msg1417397">Quote from: Prunesquallor on 08/19/2015 01:03 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.

I know I'm a broken record, but IMHO there are many more uncontrollable favors in low earth orbit than in the lab, considering the minscule power available for the thruster on a cubesat.
I'm surprised that you think the protocol I described is that flawed. Obviously, as well, you'd want to repeat the experiment with the other one powered and the original (powered) one now unpowered.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 08/19/2015 04:29 AM
Something that I've been thinking about a bit recently: where are Shawyer's previous emdrive builds, and is there any sort of avenue there for an independent replication?

Correct me if I'm wrong, but Shawyer constructed at least three different emdrives and their attendant testing platforms over the last 15 years (the feasibility rig, the demonstrator and the flight thruster) as well as a possible yet unconfirmed superconducting design.  Surely these rigs still exist, as I can see no reason why he would have dismantled them.  Given that this is the case, perhaps one of the simplest avenues for an independent replication (i.e. an independent body works with the exact same device and determines whether or not they can get the exact same (within error margin) force measurement) would simply be for him to supply his prebuilt emdrives to one of the many replicators clamoring for a drive?

So I suppose I am aiming this question more or less to TheTraveller:  Has Shawyer ever expressed any interest in having his previously built and tested rigs be subjected to external examination by an independent authority?  While that may have been impossible before, surely the recent and growing media exposure will have interested a few reputable academics in doing such independent testing.  If not, maybe you, as the liaison of this forum to Shawyer, could ask him if he is interested in such a thing?         
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/19/2015 04:53 AM
You theorise as if this were about science. Shawyer runs a company. If he were to do as you suggest, he would have no control over the situation. Thus if a null result were found - or yet, a null result fabricated - he is powerless to act.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/19/2015 07:17 AM
Ok...latest thing I have been wondering (as per earlier conversation with Doctor Rodal)

Would an 'electromagnetic Dean Drive' actually move itself (and attached spacecraft) in space?  Aka high earth orbit or interplanetary space.  (Because 'electromagnetic Dean Drive' is what Rodal has mentioned more than once.)

The reduced thrust in a vacuum bothers me here.  As Shell says, giant red flag.  Also wonder how much of a vacuum for these tests as compared with very high orbit or interplanetary space. 

Another red flag is Shawyer electing to focus on EM Drive uses for within an atmosphere.  From a straightforward engineering perspective, he knows the capabilities of these devices better than anybody - maybe.  He must have a great deal of unreleased test data.

Starting to suspect that a fully depressurized EM Drive in high orbit/interplanetary space would either

1) not move the spacecraft; OR

2) have a performance comparable to a photon rocket.  Best case might be thrust a few dozen times that of a photon rocket for unclear reasons.

Still wondering if a pressurized EM Drive in high orbit / interplanetary space would produce thrust comparable to tests in atmosphere.  Question becomes - pressurized with what?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 08/19/2015 08:18 AM
I really liked this recent article on the EmDrive. Not always spoke about the Emdrive itself, but about something Mr. rfmwguy described as "chruch science" and keeping to old ways.

One can also describe it as a critic of the critique.

http://www.digitaljournal.com/science/op-ed-emdrive-does-work-but-spectator-science-disagrees/article/441374
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/19/2015 08:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417449#msg1417449">Quote from: ThinkerX on 08/19/2015 07:17 AM</a>
Ok...latest thing I have been wondering (as per earlier conversation with Doctor Rodal)

Would an 'electromagnetic Dean Drive' actually move itself (and attached spacecraft) in space?  Aka high earth orbit or interplanetary space.  (Because 'electromagnetic Dean Drive' is what Rodal has mentioned more than once.)

The reduced thrust in a vacuum bothers me here.  As Shell says, giant red flag.  Also wonder how much of a vacuum for these tests as compared with very high orbit or interplanetary space. 

Another red flag is Shawyer electing to focus on EM Drive uses for within an atmosphere.  From a straightforward engineering perspective, he knows the capabilities of these devices better than anybody - maybe.  He must have a great deal of unreleased test data.

Starting to suspect that a fully depressurized EM Drive in high orbit/interplanetary space would either

1) not move the spacecraft; OR

2) have a performance comparable to a photon rocket.  Best case might be thrust a few dozen times that of a photon rocket for unclear reasons.

Still wondering if a pressurized EM Drive in high orbit / interplanetary space would produce thrust comparable to tests in atmosphere.  Question becomes - pressurized with what?

Ya know ThinkerX we all are wondering if it would work in the vacuum of space, away from  gravitational influence. Catch here, if we have a hard time making this work here on the ground in a controlled environment, it's not ready for space. Yet.

Find out why the reduced thrust in vacuum, correct for it if you can, use it to an advantage if you can. Get stable thrusts time and time again, picking it apart bit by bit, little by little, little steps at a time, logging all the data. Building your theories, your data.

I'm reminded of the time of the Wright brothers and all those who thought they had human flight down with their contraptions and weird gizmos, they crashed, failed or died trying. Then the Wright bros did it right, built scale models, built (I think one of the very first) wind tunnels to test the models in and little by little bit by bit, logging it all ... flew and changed our world. Over a hundred years latter that basic science still rings true.

Patience Grasshopper, this isn't MacGyver (the old TV show) where with a piece of chewing gum, a bobby pin, a used battery from a personal vibrator and foobiedustballs builds a interstellar rocket. This dang thing needs to be nitpicked apart bit by bit.

Ok, back to bed, perchance to dream.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/19/2015 08:55 AM
An interesting article about measurement of resonant modes [EDIT] and position of antenna.

Dielectric square resonator investigated with microwave experiments

http://www.researchgate.net/profile/Barbara_Dietz/publication/263736539
_Investigation_of_a_Dielectric_Square_Resonator_with_Microwave_Experiments
/links/547485350cf2778985abe4a0.pdf

"gives an overview of the number of modes with a given symmetry that were unambiguously identi�fied for the diff�erent positions of the excitation antenna"
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/19/2015 09:55 AM
Dr.Rodal -

I've thought about the problem of the side wall forces, and nothing occurs to me to to explain why they might reliably net to zero, even in the light of your comments. That they net to zero may be the case, but it is not obvious: unless I'm mistaken you yourself were asking for meep data at the walls to calculate forces some number of thousand posts ago. The answer wasn't obvious to you then and it isn't obvious to me now.

Please can you give a straightforward answer as to what your argument is? Please don't bother to repeat or approximate another sequence of astoundingly condescending and arrogant questions. Throughout this discussion, right or wrong, I've tried to remain civil, constructive and adult. I'd be very grateful if you could do the same, and just respond quickly and to the point.

Thanks in advance,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 08/19/2015 11:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416890#msg1416890">Quote from: SeeShells on 08/17/2015 04:09 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416877#msg1416877">Quote from: graybeardsyseng on 08/17/2015 03:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416798#msg1416798">Quote from: zen-in on 08/17/2015 05:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416763#msg1416763">Quote from: TheTraveller on 08/17/2015 12:20 AM</a>
...

On the top of my rotary table but under all the equipment will be a thin copper layer that will serve as my reference ground plane. Everything will be grounded to this high frequency ground reference plane.
...

Anybody who has ever designed and debugged a high frequency pcb knows the value of a solid copper ground plane.

So yes ground loops can be a problem but not if using a large area solid copper ground plane with additional high frequency decoupling capacitors and ferrite donuts.

At 2.4 GHz ferrite donuts are not needed.  Instead an air core inductor inline with each power lead that is not at ground potential is all that is needed.   Filter caps on either side of the inductor are used to prevent voltage sag from current transients.  They are a high impedance path to RF.  But since the inductor only needs to be a few nH.  caps are not needed.

The fustrum is your ground plane.   No thin copper sheet is needed.   Any conductors going to this ersatz ground plane will be many wavelengths long.  So it is impossible to make this copper sheet a ground at RF.

The biggest problem with driving a fustrum from a coax feed is matching the loop inside the cavity.   It is virtually impossible to make the loop exactly the right length so it will almost never be a 50 Ohms resistive load at the frequency used.   It will always be capacitive because of the adjacent cavity walls.   So a large part of the RF sent into the cavity will just get reflected back on the shield.   Ferrites are only useful up to VHF frequencies so putting ferrite donuts on the coax will have no effect.   Maybe coiling the coax will help but a lot of RF will still get radiated because of the mismatch.   Matching networks can be used but in that case the return wave is just dissipated in the matching network.

Quite right - there is a very significant difference between power grounding and RF grounding.   At the appoximately 12cm wavelengths most folks are working with (2.45 Ghz or thereabout) any ground lead longer than about 6cm is also a pretty decent radiator.   Google RF grounding - there is wealth of info about it.   Power and safety ground are also very important.

Just a comment from those using loop antennas.   Loop antennas are magnetic antenna and work differently from antennas like dipoles and monopoles.   The common circumference for loop antennas is on the order of 1 lambda not lambda/2.   A half wavelength circmumference will have a VERY high input impedance and will be hard to couple.   A full wavelength loop will be significantly closer to 50 ohms, although wavelength variations due to excited mode and geometry of the cavity will also  have significant effects.     I will try to model up some example loops and patterns later today/tonight when I have access to the software.

Herman

I thought a 1/10 wave loop or even a simulating square loop would work well and aero and imbfan have tried to model it in meep, although it's a very tough nut to crack in the meep software.

I would love to see your models.

Shell

Sorry this has taken so long to get results on modeling.   Family responsibilities keep interrupting important EMDRIVE work  ;).  Anyway I modeled several loops - all using #18gauge (very close to 1mm) copper wire, located 1/2 wavelength above "perfect" ground.  All driven at 2450 Mhz.   Models are all based on 24 element, 7segments per element, fed at point closest to ground plane.

Shell - I haven't gotten the tenth wavelength model working yet - keep getting geometry errors from NEC.  Still working and will report as soon as possible.   lambda/10 and smaller loops are 'different' - very sharp tuning and critical.  Often losses in the loop material swamp the radiation resistance. 

Anyway - here are the input impedances for the various cases. 

one lambda loop : Z = 96.9 - j91.5 ohms
half lambda loop : Z = 553 - j87.6 ohms
two lambda loop : Z = 200 - j38 ohms

I will post far field patterns this evening.   Have to go to that darn work stuff.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/19/2015 02:01 PM
NSF-1701 update...all is now complete and the unit is mounted on the balance beam including oil dampener  plus electrodes/cups waiting for galinstan! I't try and do a video walkound of the completed test stand tonight. Once the galinstan arrives, I'll do the test. Still have to attach laser and set up mirrors and target, but for all intents and purposes...its ready to go! Wish me luck. 8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 08/19/2015 03:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417636#msg1417636">Quote from: TheTraveller on 08/19/2015 12:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417533#msg1417533">Quote from: graybeardsyseng on 08/19/2015 11:22 AM</a>
Sorry this has taken so long to get results on modeling.   Family responsibilities keep interrupting important EMDRIVE work  ;).  Anyway I modeled several loops - all using #18gauge (very close to 1mm) copper wire, located 1/2 wavelength above "perfect" ground.  All driven at 2450 Mhz.   Models are all based on 24 element, 7segments per element, fed at point closest to ground plane.

Shell - I haven't gotten the tenth wavelength model working yet - keep getting geometry errors from NEC.  Still working and will report as soon as possible.   lambda/10 and smaller loops are 'different' - very sharp tuning and critical.  Often losses in the loop material swamp the radiation resistance. 

Anyway - here are the input impedances for the various cases. 

one lambda loop : Z = 96.9 - j91.5 ohms
half lambda loop : Z = 553 - j87.6 ohms
two lambda loop : Z = 200 - j38 ohms

I will post far field patterns this evening.   Have to go to that darn work stuff.

Herman

May I ask:

1) why you used 1/2 wavelength above the ground plane and not 1/4 wave?

2) are these loop models parallel to the ground plane (same 1/2 wave spacing to the ground plane at all points of loop circumference) or orthogonal to it?

3) lambda at 2.45GHz is 122.33mm, so a 2 lambda loop is 244.67mm in circumference and 77.9mm in diameter?

Thanks so much for the information. Most appreciated.
Good Questions.

WRT

1) Old ham radio influence.  We (hams) often try to mount antennas as high as possible, up to about 1/2 wavelength, in order to maximize the low angle radiation (which is generally speaking "good" for long distance communications on lower bands).   I will run at 1/4 lambda high also and post results for both.   (changing height above ground is very easy).

2) The plane of the loop here is normal to the surface,  so orthogonal.   Most diagrams (not all by any means)  I have seen for driving waveguides/cavities used this orientation so I did this first.   I  will also run some parallel to the ground plane as well - a little harder than changing height but not too bad.

3) Yes, that is what I used.

Hope this helps,

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/19/2015 03:22 PM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417662#msg1417662">Quote from: rfmwguy on 08/19/2015 02:01 PM</a>
NSF-1701 update...all is now complete and the unit is mounted on the balance beam including oil dampener  plus electrodes/cups waiting for galinstan! I't try and do a video walkound of the completed test stand tonight. Once the galinstan arrives, I'll do the test. Still have to attach laser and set up mirrors and target, but for all intents and purposes...its ready to go! Wish me luck. 8)

I will wish you good luck.;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sghill on 08/19/2015 03:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417662#msg1417662">Quote from: rfmwguy on 08/19/2015 02:01 PM</a>
NSF-1701 update...all is now complete and the unit is mounted on the balance beam including oil dampener  plus electrodes/cups waiting for galinstan! I't try and do a video walkound of the completed test stand tonight. Once the galinstan arrives, I'll do the test. Still have to attach laser and set up mirrors and target, but for all intents and purposes...its ready to go! Wish me luck. 8)

May the force be with you.  Or at least measurable.... :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/19/2015 03:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417421#msg1417421">Quote from: deltaMass on 08/19/2015 02:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417397#msg1417397">Quote from: Prunesquallor on 08/19/2015 01:03 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.

I know I'm a broken record, but IMHO there are many more uncontrollable favors in low earth orbit than in the lab, considering the minscule power available for the thruster on a cubesat.
I'm surprised that you think the protocol I described is that flawed. Obviously, as well, you'd want to repeat the experiment with the other one powered and the original (powered) one now unpowered.

In theory, the protocol is Ok, I just don't think it's practical with inexpensive satellites like cubesats. To do what you are suggesting, you would have to:

1) Ensure identical deployment conditions. Any difference in initial velocity between the two sats would manifest itself as ever-increasing separation with time - just the effect you are looking for as a thrust indicator. Take a look at the video here:

http://nanoracks.com/products/smallsat-deployment/

At about 0:19 five cubesats are deployed and begin to develop differential velocities almost immediately.  In theory you could deployed the two sats joined and then separate with springs, but then you introduce the uncertainty of the separation dynamics.

2) Ensure identical orientation of the two sats (and appendages such as solar wings) with respect to the velocity vector, or the difference in aspect will result in differential drag and will again mimic the thrust signature.

3) Very accurately track the two sats.  Space Command radars will obtain tracking information, but this is usually only updated every few days. Intermediate orbit prediction is done by computer propagation of the Space Command solutions. These typically do not provide the kind of accuracy I suspect you would want.

With enough complexity, all of these issues could be overcome. I just don't think it would be an inexpensive undertaking. I would certainly rather put that money into more sophisticated ground testing first.

I'm still trying to put together a paper on the subject. I've got the drag modeling done, but need to formulate the conclusions.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/19/2015 04:37 PM
Thanks for the reference(s) TT.

I could see no suggestion in the Yang paper sections you pointed to indicating that the forces on the side walls net to zero. The Shawyer ppt you just referenced just says that the side wall forces are less than those on the big end. There is no support for the implicit suggestion elsewhere here that side wall forces don't need to be calculated, or perhaps can be derived simply from the end wall forces.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: MyronQG on 08/19/2015 05:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417454#msg1417454">Quote from: Chrochne on 08/19/2015 08:18 AM</a>
I really liked this recent article on the EmDrive. Not always spoke about the Emdrive itself, but about something Mr. rfmwguy described as "chruch science" and keeping to old ways.

One can also describe it as a critic of the critique.

http://www.digitaljournal.com/science/op-ed-emdrive-does-work-but-spectator-science-disagrees/article/441374

Yes, indeed is "church science" old and stagnated knowledge like saying that two plus two will always equal four (in base 10 numeration system, of course).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfcavity on 08/19/2015 05:15 PM
Instead of decrying science for being elitist, or set in the ways, why not put forth your own testable predictions? Or is that too much work?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/19/2015 05:19 PM
The Traveller; question regarding the dynamics of the EM-Drive operation.

Per Shawyer "Second generation EMDrive propulsion applied to SSTO launcher and intersteller probe" (2015) Figure 6 he shows that after application of Power it takes something like 40 milliseconds to reach max thrust. If we are talking conservation of momentum should this not be happening in microseconds (the speed of light)? Is this the cycle build up that Dr Rodal was discussing? Or is this a function of how long he expects the magnetron phase lock relay / system to power up after application of power?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/19/2015 06:38 PM
loop antennas

https://translate.google.de/translate?hl=de&sl=de&tl=en&u=http%3A%2F%2Fwww.antennenkoppler.de%2Fachim%2Fantenna%2FImpedanz_im_Smith_1.html

https://translate.google.de/translate?hl=de&sl=de&tl=en&u=http%3A%2F%2Fwww.dg1sfj.de%2Ffunk%2Fantennen%2F87-magnetic-loop-koppelschleifen%3Fshowall%3D%26start%3D2
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/19/2015 07:23 PM
Guys, check this out.
http://hackaday.com/2015/08/19/the-em-drive-might-not-work-but-we-get-helicarriers-if-it-does/

Lots of comments ...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/19/2015 07:31 PM
Stupid mistake. I had edited in the dipole antenna after the other one, then changed location of the first one, not the one being used. Here it is now, though, see attached-

I have removed and replaced the csv data for the 32 cycle run, here. Will get the longer runs up soon.

https://drive.google.com/folderview?id=0B1XizxEfB23tflFaMkhjWnBXZ3M3LUg0dFBEZEkyOGpmNnlrOGFDYTBVV25fQnZQQWU3T00&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tflFaMkhjWnBXZ3M3LUg0dFBEZEkyOGpmNnlrOGFDYTBVV25fQnZQQWU3T00&usp=sharing)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/19/2015 07:51 PM
Not sure if it makes any sense, but...

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1058080,3Bimage.pagespeed.ic.o09FJoiiLo.jpg)

Isn't this a bit misleading, knowing that the wave guide feed come from the sidewalls and a large part of the waves will simply keep bouncing around without being able to perfectly bounce between small and large (curved) plate?

We've seen (some pages ago, in one of Shell's gif's iirc) that when you bring dynamic wave motion in the cavity it does everything except bouncing nicely back an forth....

You would only achieve full efficiency on such nice bouncing patterns when your feed is at the small or big end. Else, a large part of the waves just ricochets around in all directions till the waves gets attenuated.
Sure you'll get some standing waves but what (small?) fraction will that be of the totality? Isn't that one of the main issues with poor performance?

Looking from my ignorant perspective, if you really want the maximum of waves to bounce back and forth you need to be at one of the end plates with your RF feed/wave guide...

Hence my question on unidirectional materials (like spy mirror glass for visual light).
I think one might achieve considerable larger efficiencies when you feed waves along the length axis, either to small gaps or through special materials...

But then again, I'm no scientist nor have i the required tools to calculate it, so it is a pure intuition thing... :-\


ps
would something like this free software tool be of any help in understanding wave interactions in a cavity?
http://www.problemsinelectrodynamics.com/tools/interactive-fdtd-toolbox

https://youtu.be/kyPBRSx7dDo
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/19/2015 07:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417773#msg1417773">Quote from: Mr. Peter on 08/19/2015 07:23 PM</a>
Guys, check this out.
http://hackaday.com/2015/08/19/the-em-drive-might-not-work-but-we-get-helicarriers-if-it-does/

Lots of comments ...
As a physics-educated engineer, it is difficult to experience empathy and humility when confronted with this cacophony of ignorance displayed in both the article and the comments. It is akin to watching apes jumping and screaming at one another at the zoo. So sad.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 08/19/2015 08:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417785#msg1417785">Quote from: deltaMass on 08/19/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417773#msg1417773">Quote from: Mr. Peter on 08/19/2015 07:23 PM</a>
Guys, check this out.
http://hackaday.com/2015/08/19/the-em-drive-might-not-work-but-we-get-helicarriers-if-it-does/

Lots of comments ...
As a physics-educated engineer, it is difficult to experience empathy and humility when confronted with this cacophony of ignorance displayed in both the article and the comments. It is akin to watching apes jumping and screaming at one another at the zoo. So sad.

To be honest, it remembers me this forum several months ago, when the topic started to attract attention. Well, not quite, because the moderators here are way more diligent.

My point is that people starting anew in the topic tend to say the same things, and show the same reactions.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfcavity on 08/19/2015 08:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417748#msg1417748">Quote from: TheTraveller on 08/19/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417721#msg1417721">Quote from: RERT on 08/19/2015 04:37 PM</a>
Thanks for the reference(s) TT.

I could see no suggestion in the Yang paper sections you pointed to indicating that the forces on the side walls net to zero. The Shawyer ppt you just referenced just says that the side wall forces are less than those on the big end. There is no support for the implicit suggestion elsewhere here that side wall forces don't need to be calculated, or perhaps can be derived simply from the end wall forces.

R.

Cavities with spherical end plates are different to cavities with flat end plates. With spherical end plates, set to be the radius they are from the frustum vertex, the propagated EM waves are spherical and as such the waves at the side walls are orthogonal and generate no momentum transfer on the side walls as the cosine loss angle is at max. See attached.

With flat end plates, the propagating EM waves are a dog's breakfast, as the flat end plate reflections / bounces introduce very significant phase distortion into the reflected wave and reflection not back to the vertex (as with spherical end plates) but to the side walls.

So with flat end plates, there is need to factor in side wall Forces but not required if using spherical end plates set to their radius from the frustum vertex.

Shawyer's Force equation

F = (2 P Df Q) / c

does not take the difference between spherical end plates and flat end plates into consideration as I believe it was formulated before spherical end plates were considered.

Even with this simplified assumption of EM wave action and no force on the side walls, the force on each endplate would be the same. The size of the endplates are the same in steradians, and same EM power over the same area in steradians would cancel out perfectly.

With that drawing he has disproved his own proposal.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/19/2015 09:33 PM

Agreed on it easing the cooling problem.
So you would expect that 5MW for 10micro seconds at 930MHz would generate thrust?
Frustrum Big Diameter 0.7m, Small Diameter 0.4m, Frustrum Centre Length 0.57m ; target TE012
Don't have a Q factor yet.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417749#msg1417749">Quote from: TheTraveller on 08/19/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417736#msg1417736">Quote from: CraigPichach on 08/19/2015 05:19 PM</a>
The Traveller; question regarding the dynamics of the EM-Drive operation.

Per Shawyer "Second generation EMDrive propulsion applied to SSTO launcher and intersteller probe" (2015) Figure 6 he shows that after application of Power it takes something like 40 milliseconds to reach max thrust. If we are talking conservation of momentum should this not be happening in microseconds (the speed of light)? Is this the cycle build up that Dr Rodal was discussing? Or is this a function of how long he expects the magnetron phase lock relay / system to power up after application of power?

That drawing is in reference to using 8 cavities and cycling the Rf power pulses between them, with each pulse lasting 20% of 1 cavity time constant. I believe the reason may be to reduce cavity heating.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/19/2015 09:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417785#msg1417785">Quote from: deltaMass on 08/19/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417773#msg1417773">Quote from: Mr. Peter on 08/19/2015 07:23 PM</a>
Guys, check this out.
http://hackaday.com/2015/08/19/the-em-drive-might-not-work-but-we-get-helicarriers-if-it-does/

Lots of comments ...
As a physics-educated engineer, it is difficult to experience empathy and humility when confronted with this cacophony of ignorance displayed in both the article and the comments. It is akin to watching apes jumping and screaming at one another at the zoo. So sad.
https://www.youtube.com/watch?v=wstIBq2H0z8

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/19/2015 09:50 PM
Well - It will be awhile yet for the longer runs. My stupid computer ran out of disk space so of course meep bombed on the file write. Luckily it was only the 64 cycle run, not the 128 cycles, so it only wasted half the time that it could have.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: b0nafide on 08/19/2015 10:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417785#msg1417785">Quote from: deltaMass on 08/19/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417773#msg1417773">Quote from: Mr. Peter on 08/19/2015 07:23 PM</a>
Guys, check this out.
http://hackaday.com/2015/08/19/the-em-drive-might-not-work-but-we-get-helicarriers-if-it-does/

Lots of comments ...
As a physics-educated engineer, it is difficult to experience empathy and humility when confronted with this cacophony of ignorance displayed in both the article and the comments. It is akin to watching apes jumping and screaming at one another at the zoo. So sad.
Every now and again I look at https://www.google.com/trends/explore#q=emdrive and I suspect there will be many more such articles and comment threads this year...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: b0nafide on 08/19/2015 11:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417831#msg1417831">Quote from: Rodal on 08/19/2015 10:33 PM</a>
... Poland ...?
https://www.youtube.com/watch?v=cSsTWRt0VBA
posted by Maciej Ma?
I'm not entirely certain that google trends has got that right about Poland. I didn't notice any extrodinary evidence in his video.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/19/2015 11:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417814#msg1417814">Quote from: aero on 08/19/2015 09:50 PM</a>
Well - It will be awhile yet for the longer runs. My stupid computer ran out of disk space so of course meep bombed on the file write. Luckily it was only the 64 cycle run, not the 128 cycles, so it only wasted half the time that it could have.

assuming you have a mobo with eufi bios get one of these and migrate the c drive onto it:

http://www.amazon.com/Seagate-Desktop-3-5-Inch-Internal-STBD6000100/dp/B00JBJ34WC

it is a 6 terabyte hard drive with  a SS buffer to preload the os working information and services and applications so that they do not require as many disk reads and can work faster. with an eufi enabled bios it can be partitioned so that the whole 6tbs can be one drive instead of the 2 TB max partition size limit for older versions of bios. but if you have a pre UEFI bios motherboard this will only work as 2 tb partitions and thus you cannot use it to it's full potential though the ss buffer will still potentially speed operations quite a bit.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/19/2015 11:31 PM
The Polish man has misunderstood special relativity, and has misunderstood that the products of reflections have to go somewhere and be re-reflected (assuming nonzero reflectivity). But I admire his efforts to understand nonetheless.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/20/2015 12:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417841#msg1417841">Quote from: b0nafide on 08/19/2015 11:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417831#msg1417831">Quote from: Rodal on 08/19/2015 10:33 PM</a>
... Poland ...?
....
posted by Maciej Ma?
I'm not entirely certain that google trends has got that right about Poland. I didn't notice any extrodinary evidence in his video.

His full name is Maciej Marosz. He's Pole. He's 38 yo engineer and kinda tinkerer. You can  find his blogs here:
http://maroszphysics.blogspot.com/
and here:
http://tesla4.blogspot.com/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/20/2015 01:23 AM
</lurk>
Today I was thinking about the Yang design that used the 3 port circulator to feed the cavity and a dummy load to absorb the reflected radiation.

That dummy load could be replaced with a rectenna to lower the heat load/cooling requirements.

I also read "Microwave Radiation Force on a Parallel-Plate Resonator" by Sergey N. Makarov et al.  That was interesting.

http://digitalcommons.wpi.edu/cgi/viewcontent.cgi?article=1013&context=electricalcomputerengineering-pubs


<lurk>
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/20/2015 01:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417814#msg1417814">Quote from: aero on 08/19/2015 09:50 PM</a>
Well - It will be awhile yet for the longer runs. My stupid computer ran out of disk space so of course meep bombed on the file write. Luckily it was only the 64 cycle run, not the 128 cycles, so it only wasted half the time that it could have.

Check to make sure everyone is on the correct page.  Shell was saying something on reddit about going to a new design, while you noted running the 9 degree Yang/Shell.  On the other hand the meep runs on the 9 degree have had some interesting results.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DnA915 on 08/20/2015 02:29 AM
Long time Engineering lurker here with a simple question:

What exactly are you looking for in the MEEP simulations? What defines a good EMDrive field if we don't know what is causing thrust? My thought is that if the "ideal" situation is known, why not write a genetic algorithm to optimize the chamber shape and antenna placement (or at least find some local maxima). Sure it would likely cost some EC2 compute time and money, but isn't that cheaper than iterating with actual hardware?

Thanks everyone. Really enjoying your work.
All the best!
David
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 02:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417679#msg1417679">Quote from: TheTraveller on 08/19/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417662#msg1417662">Quote from: rfmwguy on 08/19/2015 02:01 PM</a>
NSF-1701 update...all is now complete and the unit is mounted on the balance beam including oil dampener  plus electrodes/cups waiting for galinstan! I't try and do a video walkound of the completed test stand tonight. Once the galinstan arrives, I'll do the test. Still have to attach laser and set up mirrors and target, but for all intents and purposes...its ready to go! Wish me luck. 8)

If you have the time would you please measure your as built frustum dimensions and post so I can do a bit of work with my higher resolution spreadsheet.

Have you used a spectrum analyser to measure the freq spread and energy distribution of your magnetron under the load of the frustum? If not, if possible, please do so as that data may help to get a good idea of how much of the magnetron's output power spectrum will be able to form resonance and then to generate Force.

The idea is to try to avoid as much as possible what Prof Yang ran into where her frustum input bandwidth (tiny rectangle lower left in all the images) was very much out of alignment with the power output spectrum of the magnetron.
Ds = 6,25
Db = 11.01
L = 10.2 not including Db convex of abt 0,2 inches

No spectrum analysis yet. Will borrow handheld after first test. Basically, this is a stretched nasa/shawyer frustum using higher power and copper mesh on sides and Db. Insertion point from Ds in same spot as nasa loop. Test will be Ds facing down, working against convection, like lulian did. Pwr 900 watts. Test cycle times 1 minute at 100% and 5 minutes at 30% magnetron cycle time. 95 degrees in shop and high humidity...no video shots tonight, will try for Friday.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/20/2015 04:37 AM
csv's from the Yang-Shell model final 14 time slices, tenth of a cycle apart have been re-generated and uploaded. Here:

https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing)


Add - By the way, this data is for the 64 cycle run.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/20/2015 04:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417883#msg1417883">Quote from: DnA915 on 08/20/2015 02:29 AM</a>
Long time Engineering lurker here with a simple question:

What exactly are you looking for in the MEEP simulations? What defines a good EMDrive field if we don't know what is causing thrust? My thought is that if the "ideal" situation is known, why not write a genetic algorithm to optimize the chamber shape and antenna placement (or at least find some local maxima). Sure it would likely cost some EC2 compute time and money, but isn't that cheaper than iterating with actual hardware?

Thanks everyone. Really enjoying your work.
All the best!
David
There seems to be at the moment an implicit working assumption that EM field resonance is necessary for thrust. The primary use of MEEP here seems to be determining whether resonance is possible (and in what modes) for a given build configuration.. with a secondary use of investigating a number of other possible anomalous effects that might result from the application of our current theories of electromagnetism, etc (effects such as exponentially increasing Poynting vectors, evanescent waves, and many other things that I don't personally understand).

We (they) are not trying to optimize anything yet because no one knows what to optimize, if anything. Resonance might be the only generally agreed upon feature for now, and even that might turn out to be unnecessary or misleading in some way.

[Edit] And I'd like to add, as another long time lurker: I think you're doing yourself a disservice by not going back and actually reading all of the previous posts, from all 4 threads. I think you wouldn't have had to ask this question if you had gone back and REALLY caught up on this discussion from the beginning.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DnA915 on 08/20/2015 05:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417908#msg1417908">Quote from: kwertyops on 08/20/2015 04:49 AM</a>
[Edit] And I'd like to add, as another long time lurker: I think you're doing yourself a disservice by not going back and actually reading all of the previous posts, from all 4 threads. I think you wouldn't have had to ask this question if you had gone back and REALLY caught up on this discussion from the beginning.

Likely true, but my spare time isn't what it used to be. Thanks for the summary! It will be interesting to see with all the designs coming out if we start to see other patters correlating to thrust.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: arc on 08/20/2015 07:22 AM
Considering the comments here about wave dynamics and the reality of microwaves injected into the side of the frustum, has anyone actually seen a Shawyer high fidelity device? or the superconductor model?.

To have em waves created, reach resonant peak and then attenuate within the 27.5ms cycle requires an input design that does not utilize oblique side injection.

(1-1.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/20/2015 10:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417953#msg1417953">Quote from: TheTraveller on 08/20/2015 08:49 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416846#msg1416846">Quote from: X_RaY on 08/17/2015 01:15 PM</a>
And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

The attached paper is pure GOLD. Going split screen with a Google translate, the German document is Ok to read and understand. If you are building a EMDrive, you really need to understand this paper like the back of your hand. Thanks so much X-Ray for sharing and making in public.

I now understand how the antenna coupling factor can make or break the actual operational Q and how if the coupling factor is bad may phase distort the excited mode into another false quasi mode and false quasi resonance.

Because of this paper my antenna design has completely changed. I now understand why Roger Shawyer suggested I explore using TE013. Nice breadcrumb there Roger. Thanks.

From one bread crumb to another, attached is my antenna coupling factor = 1 design and where it may be placed to fully ensure TE013 excitement and fully couple to the resonant EM waves. Will be supported on 3 threaded quartz rods with will allow the loop's orientation to be adjustment to get it just right. BTW thanks SeaShells for the quartz rod idea.

Next issue is to design a loop of the correct diameter and impedance. GrayBeardSysEng can you assist?

Once the loop antenna design is established, then need to come up with a new frustum design that will put the loop diameter in the centre of the centre TE013 H field lobe.

Easy peasy right?
Yes nice paper.  :)
Your antenna location looks good.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/20/2015 12:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417953#msg1417953">Quote from: TheTraveller on 08/20/2015 08:49 AM</a>
Once the loop antenna design is established, then need to come up with a new frustum design that will put the loop diameter in the centre of the centre TE013 H field lobe.

Do you have a book or paper that talks about that kind of antenna?  It looks really long, like it might approach lambda.  I thought that caused impedance/reflection problems?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfcavity on 08/20/2015 12:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417940#msg1417940">Quote from: TheTraveller on 08/20/2015 07:54 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417797#msg1417797">Quote from: rfcavity on 08/19/2015 08:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417748#msg1417748">Quote from: TheTraveller on 08/19/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417721#msg1417721">Quote from: RERT on 08/19/2015 04:37 PM</a>
Thanks for the reference(s) TT.

I could see no suggestion in the Yang paper sections you pointed to indicating that the forces on the side walls net to zero. The Shawyer ppt you just referenced just says that the side wall forces are less than those on the big end. There is no support for the implicit suggestion elsewhere here that side wall forces don't need to be calculated, or perhaps can be derived simply from the end wall forces.

R.

Cavities with spherical end plates are different to cavities with flat end plates. With spherical end plates, set to be the radius they are from the frustum vertex, the propagated EM waves are spherical and as such the waves at the side walls are orthogonal and generate no momentum transfer on the side walls as the cosine loss angle is at max. See attached.

With flat end plates, the propagating EM waves are a dog's breakfast, as the flat end plate reflections / bounces introduce very significant phase distortion into the reflected wave and reflection not back to the vertex (as with spherical end plates) but to the side walls.

So with flat end plates, there is need to factor in side wall Forces but not required if using spherical end plates set to their radius from the frustum vertex.

Shawyer's Force equation

F = (2 P Df Q) / c

does not take the difference between spherical end plates and flat end plates into consideration as I believe it was formulated before spherical end plates were considered.

Even with this simplified assumption of EM wave action and no force on the side walls, the force on each endplate would be the same. The size of the endplates are the same in steradians, and same EM power over the same area in steradians would cancel out perfectly.

With that drawing he has disproved his own proposal.

Shawyer clearly says the Force generated is not due to the static end plate momentum as in that situation the EMDrive is in IDLE mode:

Then why should it matter if the 'wave edges' are orthogonal to the side wall? And can you give a mathematical description of 'wave edges' or at least an analogue to typical EM lingo because I'm a little confused at that point what part that is.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 01:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417869#msg1417869">Quote from: ElizabethGreene on 08/20/2015 01:23 AM</a>
</lurk>
Today I was thinking about the Yang design that used the 3 port circulator to feed the cavity and a dummy load to absorb the reflected radiation.

That dummy load could be replaced with a rectenna to lower the heat load/cooling requirements.

I also read "Microwave Radiation Force on a Parallel-Plate Resonator" by Sergey N. Makarov et al.  That was interesting.

http://digitalcommons.wpi.edu/cgi/viewcontent.cgi?article=1013&context=electricalcomputerengineering-pubs


<lurk>
Did you ever find out what was causing the microwave detector to be set off on the small end?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 01:32 PM
ABC News Australia: http://www.abc.net.au/news/2015-08-17/warp-speed-a-possibility-astrophysicist-says/6702034

"Long considered a staple of science fiction, high speed space travel between galaxies — or warp speed — may actually be possible, according to astrophysicist Professor Geraint Lewis.

Professor Lewis, from the University of Sydney, is set to deliver a talk today at the National Science Week in Sydney, and said the futuristic concept was actually part of Albert Einstein's theory of relativity."
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/20/2015 01:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418014#msg1418014">Quote from: rfmwguy on 08/20/2015 01:32 PM</a>
ABC News Australia: http://www.abc.net.au/news/2015-08-17/warp-speed-a-possibility-astrophysicist-says/6702034

"Long considered a staple of science fiction, high speed space travel between galaxies — or warp speed — may actually be possible, according to astrophysicist Professor Geraint Lewis.

Professor Lewis, from the University of Sydney, is set to deliver a talk today at the National Science Week in Sydney, and said the futuristic concept was actually part of Albert Einstein's theory of relativity."

Same Australian that wrote about the interaction of matter during acceleration and deceleration of an Alcubierre Drive:

http://arxiv.org/abs/1202.5708

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 02:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418017#msg1418017">Quote from: Rodal on 08/20/2015 01:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418014#msg1418014">Quote from: rfmwguy on 08/20/2015 01:32 PM</a>
ABC News Australia: http://www.abc.net.au/news/2015-08-17/warp-speed-a-possibility-astrophysicist-says/6702034

"Long considered a staple of science fiction, high speed space travel between galaxies — or warp speed — may actually be possible, according to astrophysicist Professor Geraint Lewis.

Professor Lewis, from the University of Sydney, is set to deliver a talk today at the National Science Week in Sydney, and said the futuristic concept was actually part of Albert Einstein's theory of relativity."

Same Australian that wrote about the interaction of matter during acceleration and deceleration of an Alcubierre Drive:

http://arxiv.org/abs/1202.5708
Thanks Doc. Looks like 3 year old info just now making some (very) public rounds. ABC and Drudge just picked up on it. Funny how things linger; then years later come to life. Guess I am so used to instant info, like our NSF pal blogged from the AIAA conference. Guerrilla science reporting... ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/20/2015 02:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418011#msg1418011">Quote from: SeeShells on 08/20/2015 01:23 PM</a>
Did you ever find out what was causing the microwave detector to be set off on the small end?

Shoddy construction and a grossly oversensitive detector.  Rodal posted a link to a paper that described my detector as garbage (in slightly nicer words).  The calibration is off significantly.  I moved it outside of the cage and have a couple of the Diode/LED Popsicle stick detectors from http://www.repairfaq.org/sam/micfaq.htm#micsimkleak inside where I can visually check them before opening.

Thanks for checking up on me.  I'm supposed to get a new soldering iron today and can get back to work.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 02:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417965#msg1417965">Quote from: X_RaY on 08/20/2015 10:28 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417953#msg1417953">Quote from: TheTraveller on 08/20/2015 08:49 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416846#msg1416846">Quote from: X_RaY on 08/17/2015 01:15 PM</a>
And no, they measured Q not Q_0, its not possible to measure Q_0 directly, one have to derive/calculate that from the complex measurement data.

The attached paper is pure GOLD. Going split screen with a Google translate, the German document is Ok to read and understand. If you are building a EMDrive, you really need to understand this paper like the back of your hand. Thanks so much X-Ray for sharing and making in public.

I now understand how the antenna coupling factor can make or break the actual operational Q and how if the coupling factor is bad may phase distort the excited mode into another false quasi mode and false quasi resonance.

Because of this paper my antenna design has completely changed. I now understand why Roger Shawyer suggested I explore using TE013. Nice breadcrumb there Roger. Thanks.

From one bread crumb to another, attached is my antenna coupling factor = 1 design and where it may be placed to fully ensure TE013 excitement and fully couple to the resonant EM waves. Will be supported on 3 threaded quartz rods with will allow the loop's orientation to be adjustment to get it just right. BTW thanks SeaShells for the quartz rod idea.

Next issue is to design a loop of the correct diameter and impedance. GrayBeardSysEng can you assist?

Once the loop antenna design is established, then need to come up with a new frustum design that will put the loop diameter in the centre of the centre TE013 H field lobe.

Easy peasy right?
Yes nice paper.  :)
Your antenna location looks good.

For the last couple days I've been going over this paper, my German is 40 years old but with google translate and it open side by side I think I'm narrowing down this second design. Thank you Xray for this paper, it's perfect and had exactly what I needed.

Got a bit of a summer intestinal bug, although not feeling well has its good points, it means I can at least sit down and get the calculator and paper out to fine tune what I want to do, what I need to do.

I should have the final design drawn up later today by tomorrow morning (depending how long I can sit at my desk :) ).  Aero can run it in meep if he pleases and Dr. Rodal can work his wonderful magic on the CSV files. So far I like this new design a lot and it isn't just mine, it's everyone's here too. Thank you all for your great inputs, you rock.

back to lurking with pen and paper....

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 02:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418029#msg1418029">Quote from: ElizabethGreene on 08/20/2015 02:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418011#msg1418011">Quote from: SeeShells on 08/20/2015 01:23 PM</a>
Did you ever find out what was causing the microwave detector to be set off on the small end?

Shoddy construction and a grossly oversensitive detector.  Rodal posted a link to a paper that described my detector as garbage (in slightly nicer words).  The calibration is off significantly.  I moved it outside of the cage and have a couple of the Diode/LED Popsicle stick detectors from http://www.repairfaq.org/sam/micfaq.htm#micsimkleak inside where I can visually check them before opening.

Thanks for checking up on me.  I'm supposed to get a new soldering iron today and can get back to work.
The devil is in the tiny details, I'm glad you got that leak figured out, leaking is bad. :) I know you're a geekster, excited to get back to work with a "new" soldering iron.

Thank you for letting us know and make it sprout wings!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/20/2015 03:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417887#msg1417887">Quote from: rfmwguy on 08/20/2015 02:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417679#msg1417679">Quote from: TheTraveller on 08/19/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417662#msg1417662">Quote from: rfmwguy on 08/19/2015 02:01 PM</a>
NSF-1701 update...all is now complete and the unit is mounted on the balance beam including oil dampener  plus electrodes/cups waiting for galinstan! I't try and do a video walkound of the completed test stand tonight. Once the galinstan arrives, I'll do the test. Still have to attach laser and set up mirrors and target, but for all intents and purposes...its ready to go! Wish me luck. 8)

If you have the time would you please measure your as built frustum dimensions and post so I can do a bit of work with my higher resolution spreadsheet.

Have you used a spectrum analyser to measure the freq spread and energy distribution of your magnetron under the load of the frustum? If not, if possible, please do so as that data may help to get a good idea of how much of the magnetron's output power spectrum will be able to form resonance and then to generate Force.

The idea is to try to avoid as much as possible what Prof Yang ran into where her frustum input bandwidth (tiny rectangle lower left in all the images) was very much out of alignment with the power output spectrum of the magnetron.
Ds = 6,25
Db = 11.01
L = 10.2 not including Db convex of abt 0,2 inches

No spectrum analysis yet. Will borrow handheld after first test. Basically, this is a stretched nasa/shawyer frustum using higher power and copper mesh on sides and Db. Insertion point from Ds in same spot as nasa loop. Test will be Ds facing down, working against convection, like lulian did. Pwr 900 watts. Test cycle times 1 minute at 100% and 5 minutes at 30% magnetron cycle time. 95 degrees in shop and high humidity...no video shots tonight, will try for Friday.
Terrific!
Can't wait to see the final results! Sir, do you intend to experiment with silver-plated cavity or liquid N2 cooled one? That'll be great.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/20/2015 03:09 PM
http://arxiv.org/abs/gr-qc/0110086

Some time ago I was thinking about how to build a more dynamic self consistent warpdrive metric.
The original Alcubierre paper shows a very arbitrary metric to produce the effect of geodesic transport of the warp bubble, and there is until now the misconception of space contraction ahead/ expansion behind to explain the warpdrive mechanism.
The Natario's paper above shows a warpdrive metric with zero contraction/expansion.
The key of warpdrive is the gtt contravariant component of metric. When that component is constant, the four vector (gtt,gtx,gty,gtz) made of the contravariant temporal metric components describes a geodesic flow in spacetime. This condition arises from ADM 3+1 metric decomposition.
The Alcubierre metric fullfils the above condition not only for the warp bubble internal region, but for entire spacetime, and it is not necessary.
The minimal conditions are:
-The gtt contravariant component must be constant inside the warp bubble, and usually set to one (no time dilation), but may have arbitrary spatio-temporal dependence outside, and decay to unity again at infinity.
-The gtx,gty,gtz contravariant components are spacial constants ( but evolving in time) and describe the velocity of the all points inside the warp bubble with relation a outside in rest observer. Outside the warp bubble region this components must decay to zero to restore the minkowski metric at infinity, and may have a arbitrary spatio-temporal dependence.
-Inside the warp bubble the other components of the metric are euclidean, and arbitrary outside near warp bubble surface, but must decay to euclidean metric at infinity too.
My idea for a dynamic warp metric temporal evolution is to mix the conditions above, in a 5D kaluza-klein scenarium evolving in a modified "Z4" formulation.
In this scenarium, the warp drive metric will be "generated" by the electromagnetic fields (gt5,g5x,g5y,g5z) + dilaton field ( g55 component) wich arise from "Z4" 5D kaluza klein metric evolution, with warp drive metric condition satisfied inside the warp bubble, and free to evolve into "Z4" formalism outside the warp bubble with non-additional conditions.
If stable, them the sources of the electromagnectic fields can be mapped into surface currents at boundary of the warp bubble, and the dilaton field will use the electromagnectic fields as source, and one can expect, of course, a turbulent gravitational/electromagnetic/dilatonic wave flow propagating from the warp bubble.

:)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 03:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418043#msg1418043">Quote from: Mr. Peter on 08/20/2015 03:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417887#msg1417887">Quote from: rfmwguy on 08/20/2015 02:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417679#msg1417679">Quote from: TheTraveller on 08/19/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417662#msg1417662">Quote from: rfmwguy on 08/19/2015 02:01 PM</a>
NSF-1701 update...all is now complete and the unit is mounted on the balance beam including oil dampener  plus electrodes/cups waiting for galinstan! I't try and do a video walkound of the completed test stand tonight. Once the galinstan arrives, I'll do the test. Still have to attach laser and set up mirrors and target, but for all intents and purposes...its ready to go! Wish me luck. 8)

If you have the time would you please measure your as built frustum dimensions and post so I can do a bit of work with my higher resolution spreadsheet.

Have you used a spectrum analyser to measure the freq spread and energy distribution of your magnetron under the load of the frustum? If not, if possible, please do so as that data may help to get a good idea of how much of the magnetron's output power spectrum will be able to form resonance and then to generate Force.

The idea is to try to avoid as much as possible what Prof Yang ran into where her frustum input bandwidth (tiny rectangle lower left in all the images) was very much out of alignment with the power output spectrum of the magnetron.
Ds = 6,25
Db = 11.01
L = 10.2 not including Db convex of abt 0,2 inches

No spectrum analysis yet. Will borrow handheld after first test. Basically, this is a stretched nasa/shawyer frustum using higher power and copper mesh on sides and Db. Insertion point from Ds in same spot as nasa loop. Test will be Ds facing down, working against convection, like lulian did. Pwr 900 watts. Test cycle times 1 minute at 100% and 5 minutes at 30% magnetron cycle time. 95 degrees in shop and high humidity...no video shots tonight, will try for Friday.
Terrific!
Can't wait to see the final results! Sir, do you intend to experiment with silver-plated cavity or liquid N2 cooled one? That'll be great.
No, since I am an individual only, building this at home with no lab, I do not expect any further development on NSF-1701. The only way this could change is if I were to be sponsored to do so, but that is a very costly proposition. Full-time emdrive development is best left for industry or government/university research labs. Unfortunately, these are not forthcoming in their process...very secretive.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/20/2015 03:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417335#msg1417335">Quote from: aero on 08/18/2015 09:20 PM</a>
I have modelled the Yang-Shell frustum with the antenna located near the big end. I have made 3 meep runs, one each for 32, 64 and 128 complete cycles with the final 14 time slices saved, a slice each one-tenth cycle. I have generated and uploaded the csv file data sets for Dr. Rodal's attention.

First, the 32 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmFENmwzYzZ5aTNVaW5sWC1YYVl5Qm4yQ3J5SmhtTkVnYUxXYUJMZzZVa1E&usp=sharing)

Second, the 64 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmlwOWVvbVB1aHA0NkMtQ0dtUjFuZks2NzZ2MGxXdWhkUTEyWWNxd2hPalE&usp=sharing)

And lastly, the 128 cycle run here:
https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing)

My apologises to SeeShells, as the png-view files are not yet available. We are working on it. I note that the Quality factor calculated by Harminv for this antenna configuration puts it well into the superconducting cavity arena. I am anxious to see the png views myself because if my thought that evanescent waves actually accomplish their superluminal behaviour via a form of tunnelling, then with this high Q model, there should be enough energy stored within the cavity to trigger tunnelling through the bases. ...
Since the csv files quoted in your message above turned out to be for the Yang/Shell cone with the antenna near the small base, a clarification is needed;

what are the quality factors of resonance (Q) for the cases with the antenna near the small base and near the big base?

Apparently when you wrote that <<the Quality factor calculated by Harminv for this antenna configuration puts it well into the superconducting cavity arena>> you were referring to the case with the antenna near the small base having such a large Q according to Meep with the constants you are using in the Drude model?

Then what is the value for the antenna near the big base?

Is it a smaller Q?  a larger Q?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/20/2015 03:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418057#msg1418057">Quote from: TheTraveller on 08/20/2015 03:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418049#msg1418049">Quote from: rfmwguy on 08/20/2015 03:10 PM</a>
No, since I am an individual only, building this at home with no lab, I do not expect any further development on NSF-1701. The only way this could change is if I were to be sponsored to do so, but that is a very costly proposition. Full-time emdrive development is best left for industry or government/university research labs. Unfortunately, these are not forthcoming in their process...very secretive.

What I find very interesting is Prof Yang's experimental data showing 4N/kW using a frustum with a Q of 1,500 and her 2013 equations suggesting exciting in a TE mode may increase end plate Force generation by a factor of 100 over excitation in a TM mode excitation.

Additionally the paper X-Ray shared, which shows if your antenna coupling factor is in the toilet, then your operational Q is likewise in the toilet.

All this excites me that there may be a doorway, using several synergistic effects to 300N/kW or higher non superconducting EMDrives.

But 1st back to my new coupling factor = 1 excitation antenna design and the EMDrive dimensional mods necessary to make it work.
Are you still looking at this September (barely a month from now) to broadcast your EM Drive rotating rig test results?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/20/2015 05:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418070#msg1418070">Quote from: TheTraveller on 08/20/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418062#msg1418062">Quote from: Rodal on 08/20/2015 03:52 PM</a>
Are you still looking at this September (barely a month from now) to broadcast your EM Drive rotating rig test results?

Expect to have some data published my end Sept. My radiation treatment starts mid Sept to end Oct but docs say should have minimal effect on my workshop time.

This new antenna design is not for 1st test unit. Have 5 variations in mind to dev higher specific Force.

Great! Are you going to cool the cavity down with liquid N2 or He for few minutes to test the higher Q if your emdrive works? I believe it's worth to give it a shot.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/20/2015 05:23 PM
Dr. Rodal -

I have your question written down.

"Then what is the value for the antenna near the big base? Is it a smaller Q?  a larger Q?"

You are right, I suspect my prior Q calculations, in particular the Q  with the 2d loop antenna toward the small end is suspect. I am quite confident of my Q value calculation with the antenna toward the big end as part of this latest effort involved assuring resonance at that location. I will provide both values at once as only one value will not help much. Note that I am confident of the calculation, not to imply that the calculation produces a real world value.

I am currently completing the 128 cycle run with the antenna really located toward the big end, really - trust me. ;D

Once that is complete, I will move the antenna back toward the small end and re-run Harminv. I will also need to generate this starting image with the antenna toward the small end - can't have it sticking through the side now can we?

aero.

P.S. The first image is from the end of the 64 cycle run, and offset from the z axis (offset 40 columns in the y direction at 1.1mm/column =4.4 cm). Same view as this starting image. This is the starting image I will need to make in order to show proper location of the antenna toward the small base.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/20/2015 05:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417709#msg1417709">Quote from: Prunesquallor on 08/19/2015 03:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417421#msg1417421">Quote from: deltaMass on 08/19/2015 02:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417397#msg1417397">Quote from: Prunesquallor on 08/19/2015 01:03 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.

I know I'm a broken record, but IMHO there are many more uncontrollable favors in low earth orbit than in the lab, considering the minscule power available for the thruster on a cubesat.
I'm surprised that you think the protocol I described is that flawed. Obviously, as well, you'd want to repeat the experiment with the other one powered and the original (powered) one now unpowered.

In theory, the protocol is Ok, I just don't think it's practical with inexpensive satellites like cubesats. To do what you are suggesting, you would have to:

1) Ensure identical deployment conditions. Any difference in initial velocity between the two sats would manifest itself as ever-increasing separation with time - just the effect you are looking for as a thrust indicator. Take a look at the video here:

http://nanoracks.com/products/smallsat-deployment/

At about 0:19 five cubesats are deployed and begin to develop differential velocities almost immediately.  In theory you could deployed the two sats joined and then separate with springs, but then you introduce the uncertainty of the separation dynamics.

2) Ensure identical orientation of the two sats (and appendages such as solar wings) with respect to the velocity vector, or the difference in aspect will result in differential drag and will again mimic the thrust signature.

3) Very accurately track the two sats.  Space Command radars will obtain tracking information, but this is usually only updated every few days. Intermediate orbit prediction is done by computer propagation of the Space Command solutions. These typically do not provide the kind of accuracy I suspect you would want.

With enough complexity, all of these issues could be overcome. I just don't think it would be an inexpensive undertaking. I would certainly rather put that money into more sophisticated ground testing first.

I'm still trying to put together a paper on the subject. I've got the drag modeling done, but need to formulate the conclusions.

To put some numbers to item 1) above, these plots show the motion of one satellite relative to another over a period of one day if an initial differential velocity of 1 cm/s is present.  In this coordinate system, "Downtrack Distance" is positive in the direction of the orbital velocity vector, "Vertical Distance" is positive in the nadir direction, "XTrack Distance" is positive in a direction opposite of the orbital angular momentum.

To visualize, one satellite would be at the origin, the other (with the initial velocity error) would follow the trajectory shown.  There are no drag or thrust forces here.  This is simply the result of orbital mechanics.  The initial relative velocity was set arbitrarily in at 0.58i + 0.58j + 0.58k cm/s.

Oscillations in vertical and crosstrack distances are immediately induced with amplitudes of around 20 m and 10 m respectively and periods of 90 minutes (orbital period).  A secular downtrack drift results in nearly 1.5 km separation after one day.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/20/2015 06:00 PM
Great job. What you're doing here is essentially a calibration. I envisage the drive-to-drive distance measured by onboard LIDAR. Now with calibration, one can power on one of the modules. Or use a 3rd as the observation platform. I think maintaining orientation wrt the thrust vector is one of the biggest challenges.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/20/2015 06:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418101#msg1418101">Quote from: deltaMass on 08/20/2015 06:00 PM</a>
Great job. What you're doing here is essentially a calibration. I envisage the drive-to-drive distance measured by onboard LIDAR. Now with calibration, one can power on one of the modules. Or use a 3rd as the observation platform. I think maintaining orientation wrt the thrust vector is one of the biggest challenges.

That's similar to what the GRACE mission did for earth and what GRAIL did for the moon.  Both used two satellites with relative ranging to translate relative velocity differences into gravity field maps.

However, these used very challenging active orbital maneuvering to get the orbits matched up just right.  As I said in the original post, what you're proposing isn't impossible, but I suspect it will outstrip the capabilities of relatively cheap spacecraft/missions.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 06:15 PM
FYI only:

There is a new emdrive builders wiki started last Friday:

http://emdrive.io/community/

Think it is by invite only for posting, but might be open for reading.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 06:32 PM
So, been thinking about a suitable lab in case further experimentation on NSF-1701 is desired. Here's a stream of consciousness list of the test gear I'd like to get my hands on (all calibrated with computer interface, RF stuff 3 GHz minimum):

Faraday cage (small room size)
Spectrum analyzer
VNA
Vacuum chamber
Weight scales 0.001g resolution
MW leakage meter
EMF meter
Ion counter
Geiger counter
Thermal imager
Air flow meter
Thermometer
Humidity sensor
Laser interferometer
Signal generator
Return loss bridge
Power meter
Dual channel oscilloscope
16 channel data logger
Computer
Custom software (aka LabView, etc)

OK, what are we missing...hmmm

<edit> I stopped counting at $100,000
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 06:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418119#msg1418119">Quote from: rfmwguy on 08/20/2015 06:32 PM</a>
So, been thinking about a suitable lab in case further experimentation on NSF-1701 is desired. Here's a stream of consciousness list of the test gear I'd like to get my hands on (all calibrated with computer interface, RF stuff 3 GHz minimum):

Faraday cage (small room size)
Spectrum analyzer
VNA
Vacuum chamber
Weight scales 0.001g resolution
MW leakage meter
EMF meter
Ion counter
Geiger counter
Thermal imager
Air flow meter
Thermometer
Humidity sensor
Laser interferometer
Signal generator
Return loss bridge
Power meter
Dual channel oscilloscope
16 channel data logger
Computer
Custom software (aka LabView, etc)

OK, what are we missing...hmmm

<edit> I stopped counting at $100,000
Tools to make advanced frustums wrt machine shop tools.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 07:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418125#msg1418125">Quote from: SeeShells on 08/20/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418119#msg1418119">Quote from: rfmwguy on 08/20/2015 06:32 PM</a>
So, been thinking about a suitable lab in case further experimentation on NSF-1701 is desired. Here's a stream of consciousness list of the test gear I'd like to get my hands on (all calibrated with computer interface, RF stuff 3 GHz minimum):

(...)OK, what are we missing...hmmm

<edit> I stopped counting at $100,000
Tools to make advanced frustums wrt machine shop tools.
Good catch shell, of course...looks like my estimate doubled to about $400K total not including building.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/20/2015 07:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417999#msg1417999">Quote from: TheTraveller on 08/20/2015 12:34 PM</a>
The "antenna" is really just 1 coil of a solenoid, designed to create a magnetic field axial in the frustum and centred in the middle lobe of a TE013 resonate mode.

That's exactly what I thought and wanted to show in my own sketch (a one-loop solenoid put exactly in the lobe of the excited mode) but X_RaY then stated:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASAloop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.

So maybe my sketch wasn't so greatly executed, showing a one-loop solenoid. The loop antenna in Eagleworks' picture is not a solenoid, it is like a little horseshoe, one extremity being grounded:

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057032,3Bimage.pagespeed.ic.AwGtB_pjPB.jpg)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/20/2015 08:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418141#msg1418141">Quote from: flux_capacitor on 08/20/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417999#msg1417999">Quote from: TheTraveller on 08/20/2015 12:34 PM</a>
The "antenna" is really just 1 coil of a solenoid, designed to create a magnetic field axial in the frustum and centred in the middle lobe of a TE013 resonate mode.

That's exactly what I thought and wanted to show in my own sketch (a one-loop solenoid put exactly in the lobe of the excited mode) but X_RaY then stated:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416711#msg1416711">Quote from: X_RaY on 08/16/2015 07:25 PM</a>
The antennas in the sketch don't work as a loop! The loop has to be in contact to the other potential, in this case the frustum, and better the length of the loop is max a half wavelength ;)
In the sketch the wave would travel along the feed and split into two parts, this parts cancel each other at half the way along the ring.. itś like two dipoles in opposite phi directions...
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416723#msg1416723">Quote from: X_RaY on 08/16/2015 07:47 PM</a>
No. please look at the NASAloop picture. One end of the wire is in contact to the GND and that is the way it will work as a loop.

So maybe my sketch wasn't so greatly executed, showing a one-loop solenoid. The loop antenna in Eagleworks' picture is not a solenoid, it is like a little horseshoe, one extremity being grounded:

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057032,3Bimage.pagespeed.ic.AwGtB_pjPB.jpg)
The ground at the end of the loop is correct, the other must be connected to the HF source. (Galvanic coupling or Capacitor to the ground will work. http://forum.nasaspaceflight.com/index.php?topic=37642.msg1410718#msg1410718 )
Without that it doesn't work as a magnetic loop antenna. Good impedance match is also good choice.
TT i told the location of his antenna is a good choice. Nothing else.
Your sketch was to much simplified (TT also but i dont like to post the same thing again and again.. And i
 assume that this was already clarified point)

Nevertheless i am not sure but i think the antenna loop could be too long for perfect coupling TE01.
Again all half wavelength the field changes the direction at/around the loop wire...

ElizabethGreene pointed this out here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417996#msg1417996

May be 0.75...1.1 Lambda is a good choice...(proposed by Herman aka graybeardsyseng)
For my max. 0.5 lambda statement i missed the capacitive part to get impedance match, but this can also be done with a external capacitor in the line! http://www.nonstopsystems.com/radio/frank_radio_antenna_magloop.htm
or a HF tuner

(Numbers in the diagram for the length of a magnetic loop are in Lambda, only loop without external capacitor)
Source: https://translate.google.de/translate?sl=de&tl=en&js=y&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.antennenkoppler.de%2Fachim%2Fantenna%2FImpedanz_im_Smith_1.html&edit-text=Ja%2C+wenn+Sie+diese+Mode+mit+hoher+Q.+erregen+wollen&act=url

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/20/2015 08:14 PM
Anyone remember how long it took our Roumanian friend Iulian to build and test his rig? As I recall it was quite speedy.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/20/2015 09:13 PM
TT - Thanks for your posting of the stuff from Shawyer. Seems to very directly address some of the concerns which have circulated about bouyancy, off-gassing, and geomagnetic effects, and overall quite positive. On the geomagnetic test, 0 degrees and 90 degrees (not sure from what base, but maybe N and E/W)  wasn't what I would have chosen. The most extreme directions for any effect are likely to include North-and-down-dip and South-and-up-dip (in NH). One could add normal to that line and horizontal to cover more possible patterns of effect.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 09:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418179#msg1418179">Quote from: deltaMass on 08/20/2015 08:14 PM</a>
Anyone remember how long it took our Roumanian friend Iulian to build and test his rig? As I recall it was quite speedy.
Not exactly, but think it was less than 1 month. OK, you're about to hammer me, aren't you DM  ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 09:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418234#msg1418234">Quote from: rfmwguy on 08/20/2015 09:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418179#msg1418179">Quote from: deltaMass on 08/20/2015 08:14 PM</a>
Anyone remember how long it took our Roumanian friend Iulian to build and test his rig? As I recall it was quite speedy.
Not exactly, but think it was less than 1 month. OK, you're about to hammer me, aren't you DM  ;)
Poke poke poke. We need to find a shower curtain to hang them off from. ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/20/2015 09:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418179#msg1418179">Quote from: deltaMass on 08/20/2015 08:14 PM</a>
Anyone remember how long it took our Roumanian friend Iulian to build and test his rig? As I recall it was quite speedy.
Yea, that was quite speedy, but his setup was not very complex. Same for measurement, so not many sensors hence not much of a data. But yes, the most important quantity - thrust has been measured.
Btw, have you seen this?
https://www.youtube.com/watch?v=z98q-DXoJCo
or this:
https://www.youtube.com/watch?v=7qWMIKVmd6w

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/20/2015 09:45 PM
This shows....?? ... that in Kyrghistan they hang bicycles from shower curtains?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/20/2015 09:58 PM
csv files for the 128 cycle run with the 2d dipole antenna located toward the big end have been upoladed to Google drive. Here.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmRvWXRHM0xWMGRpWU84RlNwQktDR3dqZWpfVDBhbEhDR2RwMEJYMERDVEE&usp=sharing)

I also uploaded the final time slice at 128 cycles offset 4.4 cm in the y direction. copy attached. As for looks, it looks almost exactly the same as the same slice at 64 cycles which is a result of the automatic scaling used. Maybe I could figure out how to scale these individual png's to the largest values but that is low priority. Dr. Rodal will calculate much more meaningful information.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 09:59 PM
Shell's Crazy Eddie

Large diameter 0.2950m
Small diameter 0.1600m
Center length   0.2620m
TE012 excitation
Frustum cone shaped, (I gave in)
Floating small ceramic plate in a tune chamber secured to the large plate with a quartz rod running through the center of the frustum.
O2 Copper bonded onto the ceramic plate with silver electroplating. (no gold)

External magnetron coupled to 4 loops internally at H plane 180 phase shifted 
2.47 GHz, stabilized, extra fin cooling, Estimated 1200 watt 100% duty cycle.

I'll use a TE10 waveguide launcher > h-plane splitter> waveguide into a coax adapter> Use a coax 90 deg hybrid 3 dB splitter on each h-arm. Coax will be 2 equal length for 2 phase matched lines. And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.

Sound good?

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/20/2015 10:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418130#msg1418130">Quote from: rfmwguy on 08/20/2015 07:01 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418125#msg1418125">Quote from: SeeShells on 08/20/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418119#msg1418119">Quote from: rfmwguy on 08/20/2015 06:32 PM</a>
So, been thinking about a suitable lab in case further experimentation on NSF-1701 is desired. Here's a stream of consciousness list of the test gear I'd like to get my hands on (all calibrated with computer interface, RF stuff 3 GHz minimum):

(...)OK, what are we missing...hmmm

<edit> I stopped counting at $100,000
Tools to make advanced frustums wrt machine shop tools.
Good catch shell, of course...looks like my estimate doubled to about $400K total not including building.

So about the same capital cost as a gas station, plus say $250K a year in salaries and another $100K in materials/misc.  So around $1m and two years for a useful prototype (if such a thing is even possible).  That's a large grant or an average sized early stage venture capital project.  Doable, but difficult.  At around 200N/Kwh you're approaching the output of a turbojet, that's certainly interesting if it can be achieved.  Also, um if the drive doesn't pan out is there any chance the research could lead to a better way to cook a potato?

For venture capital my gut is telling me that you'd need thrust outside of the noise range, say 1N and some indication that better can be reached.  A working theory that does not violate CoE or CoM would also be helpful, as would some press releases before seeking funding. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/20/2015 10:28 PM
NSF-1701 Update, pass it along, I will only post it here on NSF:

First "Flight" Test Tuesday, August 25, 2015 2:00 PM Eastern Standard Time USA, 18:00 Hours UTC

It will be a recorded video, not live as EM interference trashes WiFi camera, too long of a run for USB cam and wired security cam not able to interface with Ustream (don't ask - long story). Also, it was suggested not to go live if a problem occurs; causing grief to both myself and audience. Be assured there will be no video editing involved.

Will post here when the video is uploaded to my youtube channel on Tuesday. Probably will take about 30 minutes to upload and process on the youtube site.

<edit>
Was just informed that my next scheduled appearance on Dark Matters Digital Network's Other Side of Midnight will be next thursday/friday 12:00 Midnight to 2:00 AM Pacific Daylight Time. I will be discussing NSF-1701 results and unlike the last appearance, have time to take questions.

I was informed by the producer that several emailers mentioned my last appearance was their favorite show (which is new on the network). I credit Mr. Hoagland for being well-informed on the topic and very interested in getting the real story out there from a grass-roots design perspective. Should be fun.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/20/2015 10:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/20/2015 10:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Flat ends. Try as I might, I cannot get a uniform curve on an english wheel, miss my old tool room lathe.

Never used Shawyers' & TT's spreadsheet, maybe I should try it. A good thing we agree.

Working on my drawing I'll post as soon as I get it done. Maybe later tonight.

Shell

Added... I'll be danged if it doesn't agree.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/21/2015 12:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1058554

My length is a little less as I have the top Small Plate being adjustable with a quartz rod in a top round tuning chamber. The side walls will slide past the small plate during the thermal expansion of the copper sidewalls still keeping the tune length correct.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/21/2015 12:16 AM
This article has some interesting insight into how a force could hide from detection in a lab. It is about a lab test to find dark matter particles responsible for cosmic expansion. These "chameleon" particles act differently in or near matter than they do in open space.

http://www.sciencedaily.com/releases/2015/08/150820144719.htm
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/21/2015 01:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418272#msg1418272">Quote from: rfmwguy on 08/20/2015 10:28 PM</a>
NSF-1701 Update, pass it along, I will only post it here on NSF:

First "Flight" Test Tuesday, August 25, 2015 2:00 PM Eastern Standard Time USA, 18:00 Hours UTC

It will be a recorded video, not live as EM interference trashes WiFi camera, too long of a run for USB cam and wired security cam not able to interface with Ustream (don't ask - long story). Also, it was suggested not to go live if a problem occurs; causing grief to both myself and audience. Be assured there will be no video editing involved.

Will post here when the video is uploaded to my youtube channel on Tuesday. Probably will take about 30 minutes to upload and process on the youtube site.

<edit>
Was just informed that my next scheduled appearance on Dark Matters Digital Network's Other Side of Midnight will be next Tuesday/Wednesday 12:00 Midnight to 2:00 AM Pacific Daylight Time. I will be discussing NSF-1701 results and unlike the last appearance, have time to take questions.

I was informed by the producer that several emailers mentioned my last appearance was their favorite show (which is new on the network). I credit Mr. Hoagland for being well-informed on the topic and very interested in getting the real story out there from a grass-roots design perspective. Should be fun.

Might I humbly suggest you make available your coordinates and stream a reasonably accurate time hack?  This will allow those interested to compute magnetic field vectors, heliocentric velocities, etc.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/21/2015 01:47 AM
Have finished the Harminv run and the result was not what I had thought. In this case the only change I made was to change the sign on the antenna z coordinate. Since zero is at the center of the longitudinal (z) axis, the change just put the antenna closer to the other end as you can see from the attached images. And as I was concerned about, the length of the dipoles and separation makes the antenna almost to large for the cavity. Almost but not quite as there doesn't seem to be any field pattern outside the boundary. And note that meep (out of the box) does not seem to connect the antenna current source to the metal cavity.

Further note that the value of Q calculated bears only generally on the quality factor of the real device. In this case, with the Q value for the cavity with the antennas toward the big end being only one order of magnitude larger than the Q value with the antenna toward the small end, it may be indicating that the big end location is superior for resonance. But the difference may alternatively be an artefact of Harminv and the calculations. I will say with some confidence that both configurations resonate well.


BE 2.2 check   frequency    imag. freq.    Q               |amp|    amplitude    error
   harminv0:   2.4657824188   -2.79E-009   441,448,007    0.023802664    0.020238611520349573-0.012528583932182084i    2.8938090806567264e-9+0.0i
                     
SE 2.2 check   frequency    imag. freq.    Q               |amp|    amplitude    error
   harminv0:   2.4657823283   -2.66E-008   46,281,090    0.1128723313    0.09597158509016332+0.059410588518131996i    1.3712434783827848e-10+0.0i
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/21/2015 02:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418326#msg1418326">Quote from: Prunesquallor on 08/21/2015 01:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418272#msg1418272">Quote from: rfmwguy on 08/20/2015 10:28 PM</a>
NSF-1701 Update, pass it along, I will only post it here on NSF:

First "Flight" Test Tuesday, August 25, 2015 2:00 PM Eastern Standard Time USA, 18:00 Hours UTC

It will be a recorded video, not live as EM interference trashes WiFi camera, too long of a run for USB cam and wired security cam not able to interface with Ustream (don't ask - long story). Also, it was suggested not to go live if a problem occurs; causing grief to both myself and audience. Be assured there will be no video editing involved.

Will post here when the video is uploaded to my youtube channel on Tuesday. Probably will take about 30 minutes to upload and process on the youtube site.

<edit>
Was just informed that my next scheduled appearance on Dark Matters Digital Network's Other Side of Midnight will be next Tuesday/Wednesday 12:00 Midnight to 2:00 AM Pacific Daylight Time. I will be discussing NSF-1701 results and unlike the last appearance, have time to take questions.

I was informed by the producer that several emailers mentioned my last appearance was their favorite show (which is new on the network). I credit Mr. Hoagland for being well-informed on the topic and very interested in getting the real story out there from a grass-roots design perspective. Should be fun.

Might I humbly suggest you make available your coordinates and stream a reasonably accurate time hack?  This will allow those interested to compute magnetic field vectors, heliocentric velocities, etc.
2 things, appearance moved to next Thursday/Friday.
What is a time hack? Sorry don't follow...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/21/2015 03:06 AM
a time hack refers to synchronizing clocks so that all participant in an endeavor are on the same time to the best accuracy possible.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: snoozdoc on 08/21/2015 03:10 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418335#msg1418335">Quote from: rfmwguy on 08/21/2015 02:12 AM</a>

 ... What is a time hack? Sorry don't follow...

If you include your geographic GPS coordinates and a video of say your cell phone showing your Greenwich Mean Time to the nearest second (or better) (a time hack), as well as the direction of north relative to your experiment, it would allow for calculation of the velocity of your workshop within the solar system including the orbital velocity of earth around the sun and the rotational velocity of the earth.  This is just in case these motions are in anyway are connected to the forces that you measure.

If you cut the video at any point then when you restart it you should ideally include another "time hack" (video shot of your GMT time on say your cell phone) to re-synchronize your experiment to your local velocity calculations.

If you know your local magnetic deviation from true north that might also be helpful.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/21/2015 03:22 AM
What's all this "Likes Given" malarkey?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/21/2015 03:24 AM
i believe it is a count of how many times you have liked other people's posts.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/21/2015 03:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418341#msg1418341">Quote from: snoozdoc on 08/21/2015 03:10 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418335#msg1418335">Quote from: rfmwguy on 08/21/2015 02:12 AM</a>

 ... What is a time hack? Sorry don't follow...

If you include your geographic GPS coordinates and a video of say your cell phone showing your Greenwich Mean Time to the nearest second (or better) (a time hack), as well as the direction of north relative to your experiment, it would allow for calculation of the velocity of your workshop within the solar system including the orbital velocity of earth around the sun and the rotational velocity of the earth.  This is just in case these motions are in anyway are connected to the forces that you measure.

If you cut the video at any point then when you restart it you should ideally include another "time hack" (video shot of your GMT time on say your cell phone) to re-synchronize your experiment to your local velocity calculations.

If you know your local magnetic deviation from true north that might also be helpful.

Exactly. And if you don't want to disclose your precise coordinates (I wouldn't), three significant figures should be adequate.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 05:27 AM
Mr. TheTraveller, would you be so kind as to answer my question please? Of course, if that was not too nosy.

Peter.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 06:45 AM
Certainly, the antenna coupling is extremely important factor, as always with rf, but I'm afraid (if Mr. Rodal and I are right)  with liquid N2 you could gain the Q by a factor of 2.8 or somewhere in that region.
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416069#msg1416069

Still, definitely  worth trying.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 07:13 AM
Because, according to Mr. Rodal's math, the Q is directly proportional to the square root of the cavity conductivity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 08:48 AM
The skin depth for copper at 2.4Ghz at 20C is about 1.3µm, while at 75K is only about 0.47µm.
Don't hold me to that though, cos I'm not sure what's the relative permeability of copper at 75K, but if it's about 1, the above numbers are correct. So yep, your cavity gets 8 times better conductance and consequently becomes 3 times more skinny.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/21/2015 09:31 AM
another article: you could call it a magnetic field wormhole emulator, yet another example of synthetic monopole or a neat magnetic waveguide:

http://www.livescience.com/51925-magnetic-wormhole-created.html

Of course; it's really not what the article hype makes of it but it is interesting and looks like it might have serious applications for shielding, control of magnetic fields, sensors and other things. I figured it might have some applicability to future EM Drive test articles so what the heck i thought i would share it here...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 09:49 AM
Mr. TheTraveller.
That's definitely not my theory, to be honest I'v asked Mr. Rodal a similar question as your sir, which was this:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1415946#msg1415946
and he was kind enough to share his thoughts with us about this subject here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416014#msg1416014

Peter.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 11:41 AM
Mr. TheTraveller
Sorry sir, but I'm not smart enough to judge whether your or Dr. Rodal's point is 100% valid or not,
but I wish you all the best on your research path anyway.
I don't know if ybco thin film small cavity or even copper one if cooled  to helium temp can gain the Q 840 times and maybe lift your puppy off the ground. Or at least, with a cup of  liquid nitrogen, speed it up on your rotating table quite significantly.
I hope so, I think the best way to find out, is to buy some N2 and few polystyrene sheets.
Can't wait for the final countdown!

Peter.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/21/2015 11:55 AM
Q is inversely proportional to the square root of the resistivity of the conductor, or since conductivity is the inverse of resistivity, one can equally state that Q is proportional to the square root of the conductivity of the conductor.

Electrical resistivity is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current. A low resistivity indicates a material that readily allows the movement of electric charge.

This is the reason why CERN is using superconducting cavity resonators, and the reason why Shawyer has been exploring superconducting cavity resonators:  the higher the (square root of the) conductivity, the higher the Q.  In theory, a superconducting cavity translates to very high Q's.

Where does this come from?  It comes from the definition of Q:

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1058604,3Bimage.pagespeed.ic._w1BVK08lw.webp)

In those expressions for Q, the energy dissipated per cycle, (proportional to the power loss), in a cavity made of a conductor like copper, is proportional to the skin depth (times the surface integral of the square of the electromagnetic field, over the internal surface of the conducting cavity).  The AC current density J in a conductor decreases exponentially from its value at the surface according to the depth d from the surface, as follows

(1205a2cff61e72e90ad4ed2ccb77bffb.png)

where δ is called the skin depth. The skin depth is thus defined as the depth below the surface of the conductor at which the current density has fallen to 1/e (about 0.37) of JS. In normal cases it is well approximated as:

(93c6c445aefed3e6d8f6c8f6c4e779e1.png)

where

 \rho  = resistivity of the conductor
 \omega  = angular frequency of current = 2π × frequency
 \mu_r  = relative magnetic permeability of the conductor
 \mu_0  = the permeability of free space

thus Q is inversely proportional to skin depth, therefore inversely proportional to the square root of the resistivity of the cavity internal surface, or equivalently, Q is proportional to the square root of its conductivity.

Nothing new here.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 12:30 PM
Well, I'm glad we all agree on that one.
So, as I said before, one can probably boost the Q by a factor of 2.8.
Now the question is what is the amount of thrust we can get from this boost?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/21/2015 12:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418437#msg1418437">Quote from: Mr. Peter on 08/21/2015 12:30 PM</a>
Well, I'm glad we all agree on that one.
So, as I said before, one can probably boost the Q by a factor of 2.8.
Now the question is what is the amount of thrust we can get from this boost?
Well, the answer is simple, everything else being the same, just substitute your value of Q in the appropriate formula.

If you follow Shawyer's, McCulloch's and Notsosureofit's formulas, they are all proportional to Q so if you increase the Q by a factor of 2.8, everything else being the same, the force should be 2.8 times greater to the extent you trust those formulas.

On the other hand if you prefer some of Todd "WarpTech" formulations the force is not strictly proportional to Q.

Finally, if you think that the EM Drive is an experimental artifact the true thrust force is zero regardless of what you do to the Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 12:40 PM
Yea, that was sneaky  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/21/2015 01:08 PM
Rodal is correct and is quoting canon. It is not his invention. It is common knowledge for students of the subject - that is, undergraduates in either physics or electrical engineering.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/21/2015 01:37 PM
Have a favor to ask my NSF pals here...on my 2 hour guest appearance next Thursday/Friday on the digital radio show, the last hour is being left open for callers questions/comments. Rather than the general audience, I'd like NSF folks to call in. It will be fun to hear your voices and get your perspective on the concept/project whether for or against the theories out there. Also a chance to update on your own project (see-shell) ;)

Date is 8/28, call in time about 1:00 AM Pacific Daylight Time 08:00 UTC

Phone No.: (505) 796-8802
Skype: enterprisemission

Should be fun...first names or NSF nicknames only are cool.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: b ramsey on 08/21/2015 02:28 PM
What's the name of the website you can listen to the digital radio show on.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kencolangelo on 08/21/2015 05:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418282#msg1418282">Quote from: SeeShells on 08/20/2015 10:59 PM</a>
Flat ends. Try as I might, I cannot get a uniform curve on an english wheel, miss my old tool room lathe.
Shell
Maybe try hydroforming? Works for fuel tanks. Looks fun anyway.
http://unreasonablerocket.blogspot.com/2007/01/normal-metal-tanks.html
(http://)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/21/2015 05:24 PM
These runs with Meep (thanks, @aero), post-processed with a program I wrote in Wolfram Mathematica make it clear how useful it  is to model the EM Drive, solving Maxwell's partial differential equations in time with the RF feed on. 

1) The RF feed is most important: with the RF feed off there is no force reported.  It is critical for all experimenters to run experiments separately with the RF feed located near the big base and for the RF feed located near the small base to learn what is really going on with the EM Drive

2) The location of the RF feed is critical: completely different results are predicted if the RF feed is located near the big base than if located near the small base.

3) The results in the spreadsheet show that:

a) If a displacement (and hence, starting from rest, an acceleration) towards the small base is measured in experiments with the antenna located near the small base (for this case, a electromagnetic force is predicted to act towards the big base ), this would be consistent with Shawyer's theory (net electromagnetic force towards big base results in acceleration towards small base due to conservation of momentum) and with White's QV theory: pushing virtual particles towards big base results in acceleration towards small base.

However, notice that a net force difference (between the forces at the bases) such that the net force points towards the big base can easily be canceled out by the force on the lateral conical surfaces. 

The reason for this is obvious: the truncated cone is tapered such that the force vector acting on the lateral conical walls can be decomposed along two vector components: one vector component oriented perpendicular to the longitudinal axis of axi-symmetry of the cone, which is self-cancelling (by symmetry) and a vector component along the axis of axi-symmetry of the cone, which must be oriented towards the small base (due to the fact that the TE mode applies an electromagnetic pressure on the conical wall surfaces).

Also, the exact solution for spherical waves in a truncated cone with spherical ends shows that the force from the lateral conical surfaces points towards the small base and it exactly cancels out the net force differential between the bases pointing towards the big base. So, placing the antenna near the small base will actually result in no net motion of the EM Drive according to classical physics.  For the antenna located near the small base, if there is motion (that is not an experimental artifact) it has to be explained by a theory outside classical physics.

_________________________

b) On the other hand, with the antenna located near the big base, the net force differential between the bases is predicted to point in the direction towards the small base.  As previously explained, this force cannot be balanced by the lateral conical surfaces (since for TE modes, the stress on the lateral conical surface is a pressure, and hence the force resultant must always point towards the small base).  Therefore, with the antenna located near the big base there appears to be a net force towards the small base that is unbalanced.  According to classical theory,  a reaction must take place through the RF feed coaxial or waveguide to balance this force.  Thus, the case of the EM Drive with the RF feed located near the big base is most interesting.  Notice that in several of the EM Drive experiments, the EM Drive has not been integrated together: they are separate in the experiments.  Thus I fully agree with deltaMass, frobnicat and TheTraveller that the best test to prove the reality (for space propulsion) or nullify the EM Drive is the one where all the components of the EM Drive, including the RF feed, and power must be integrated together, preferentially with a battery, as in the peer-reviewed tests of Brito, Milani and Galian, and of Marini and Galian that nullified a "Woodward effect" MLT type of thruster.

==>Notice that to explain motion of the EM Drive (detached from the RF source and detached from power) for case b (antenna located near the big base), it may NOT be necessary to use "New Physics" to explain motion of the EM Drive as many people are assuming.  Motion of the EM Drive for case (b) can be explained by classical physics (and hence by Meep "out of the box") as a result of artificially separating power and RF source from the EM Drive itself.  (Of course in a spaceship they cannot be separated as they are all integrated into the spaceship).   The reactions for the motion are occurring through the RF feed (coax or waveguide and power lines) to the stationary RF source and stationary power.

___________________

Attachments:

1) Spreadsheet for Yang/Shell cone angle 6 degree geometry cases for antenna located near the small base and near the big base

2) Forces at each base and net force differential between bases vs. time for the cases of the antenna located near the small base and near the big base

Acronyms:

SB=Small Base
BB=Big Base

fSB = force at small base
fBB = force at big base

t = time
Abs = Absolute Value function
Q = quality factor of resonance
μsec = microseconds
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/21/2015 05:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418464#msg1418464">Quote from: b ramsey on 08/21/2015 02:28 PM</a>
What's the name of the website you can listen to the digital radio show on.
http://othersideofmidnight.com

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: BL on 08/21/2015 06:28 PM
Per Dr. Rodal’s post #844 recommending that the DIY thrusters be tested as a self contained package, this may be a good time to revisit Mulletron’s original idea of moving ALL active electronics off the thrust measuring platform and coupling the microwave power onto the platform via a microwave link with an air gap.  Over the short distances required, losses can be well under a dB.

The advantages:

Lighter, more compact package on the thrust measuring platform;  only the receive antenna, the thruster, and a short cable to connect the two.
No active electronics on the platform.
No requirement for low torque power coupling schemes.
No high currents anywhere near the thrust measuring platform.
Even the power sensors required to monitor forward and reverse power can be external to the platform.
Only one power sensor required, as the sensor can be switched between forward and reverse via a computer-controlled relay while the test is running.
Laboratory grade sig gens and rack mounted broad band power amplifiers can be used.
Option for clean, precision CW signal or a custom tailored spectrum if VSG used for signal source.
Signal can be tailored to the response of the thruster in real time.
Signal parameters can be changed to investigate the sensitivity of the thrust (if any) to frequency and amplitude.
No batteries required; test duration is unlimited.
Thrust measurement platform can be enclosed easily to avoid air currents.
The only power dissipated on the thrust measurement platform comes from heating of the frustum.

Disadvantages:

Cannot be used on rotating platforms such as planned by TheTraveller.  When the platform rotates, the microwave link would be misaligned and thrust would cease.  The air gap coupling should work fine for any thrust measurement technique that does not require appreciable movement to detect thrust.  Examples would be balance beams and precision scales.  Even torsion balances would work fine as long as they only rotate a few degrees. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 08/21/2015 06:34 PM
An update on the finances of SPR.  The information presented in the following is current as of March 31st 2015.

Here is the most recent balance sheet (https://s3-eu-west-1.amazonaws.com/document-api-images-prod/docs/bzrCMmEtGgloc74n9a4tvKWRCgx50t96nhrU4CUZZZY/application-pdf?AWSAccessKeyId=ASIAIT35MGBV6PXVZWUA&Expires=1440180826&Signature=jDDJtNAaibcXN3PqaAMbPk6Gnyc%3D&x-amz-security-token=AQoDYXdzEKn%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEa4AP6wl8hym2jxstO%2BQzP8zKh4WjgZaxQQi%2BEX1Ta2i0gcYIEcZizfW5q6k2UvY%2Bamu1P22%2FqnF6fESRXsu1RhOIGxZ%2FkI5jej8h8u0xly0%2B3JvGCRbFI0p9KGvtnZX81DSe71y5kDg0QWAS4dTzi6WzlHccLP5v%2Br1P1mpUqBLqbk08Xeec4ghnSPwCwEhwPEPaXT3YsZpHCFwxpS1wmWJ23GG41HfVcr9%2B966DbT%2FDI6TZCo3EhmSgjdrJlLNM%2F9obiRhQA5Bwg%2BMd49gB8ktZGHeB44aDfitnZvMIUyawl1cmBSr581tTDO7HkJhwLSUGujObd32xLRDTSGa4c%2Bnhx4XahUI%2FxPS75NcKLhre55vkt29Bi02bgwmkrkwdtonU%2FFglu1Rbg7daiN74XUMVtlXHlzrEXXicFdu8w1mK9S0%2BgsrzRkacHWpySNhuHwtOgZgLw52sDpriY5TMU9KCOgk81nfscdgOLJPrGqs6XWMx8IPODKl0WyHusXfpe4qmTR2tmOyqlFgMS2%2BKc4SpoweqWAQ43YtU3T6hVLjXLz7LOjOm6yvu4EB3HV1eN6YJESK3XM00RNtu41QuRibiI%2BlQIDInqKFWhInFWrr3zA3uqAH2B9EhNG9LmdheQFmAg6ozdrgU%3D), which is available from the public records at the companies house database: https://beta.companieshouse.gov.uk/company/04097991/filing-history

Summary: 
No change in tangible assets from 2014-2015, meaning no new equipment has been purchased.
SPR is holding more cash than it has previously (about 15,000 pounds compared to 5,000 pounds).
Most importantly, it has paid off a portion of its long term debt, going from 240,000 to 195,000 pounds.

It currently has negative net assets of 185,000 pounds, less than the 235,000 as of the same date in 2014.  With only the balance sheet and no income statement, it is impossible to deduce where the cash to pay off the long term debt came from or if the debt was perhaps forgiven instead.  Investment can be ruled out however, as the number of outstanding shares has not changed since 2014.   

Previous posts on this subject are linked below:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1394575#msg1394575
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396231#msg1396231
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396346#msg1396346
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396365#msg1396365
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/21/2015 06:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418541#msg1418541">Quote from: wallofwolfstreet on 08/21/2015 06:34 PM</a>
An update on the finances of SPR.  The information presented in the following is current as of March 31st 2015.

Here is the most recent balance sheet (https://s3-eu-west-1.amazonaws.com/document-api-images-prod/docs/bzrCMmEtGgloc74n9a4tvKWRCgx50t96nhrU4CUZZZY/application-pdf?AWSAccessKeyId=ASIAIT35MGBV6PXVZWUA&Expires=1440180826&Signature=jDDJtNAaibcXN3PqaAMbPk6Gnyc%3D&x-amz-security-token=AQoDYXdzEKn%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEa4AP6wl8hym2jxstO%2BQzP8zKh4WjgZaxQQi%2BEX1Ta2i0gcYIEcZizfW5q6k2UvY%2Bamu1P22%2FqnF6fESRXsu1RhOIGxZ%2FkI5jej8h8u0xly0%2B3JvGCRbFI0p9KGvtnZX81DSe71y5kDg0QWAS4dTzi6WzlHccLP5v%2Br1P1mpUqBLqbk08Xeec4ghnSPwCwEhwPEPaXT3YsZpHCFwxpS1wmWJ23GG41HfVcr9%2B966DbT%2FDI6TZCo3EhmSgjdrJlLNM%2F9obiRhQA5Bwg%2BMd49gB8ktZGHeB44aDfitnZvMIUyawl1cmBSr581tTDO7HkJhwLSUGujObd32xLRDTSGa4c%2Bnhx4XahUI%2FxPS75NcKLhre55vkt29Bi02bgwmkrkwdtonU%2FFglu1Rbg7daiN74XUMVtlXHlzrEXXicFdu8w1mK9S0%2BgsrzRkacHWpySNhuHwtOgZgLw52sDpriY5TMU9KCOgk81nfscdgOLJPrGqs6XWMx8IPODKl0WyHusXfpe4qmTR2tmOyqlFgMS2%2BKc4SpoweqWAQ43YtU3T6hVLjXLz7LOjOm6yvu4EB3HV1eN6YJESK3XM00RNtu41QuRibiI%2BlQIDInqKFWhInFWrr3zA3uqAH2B9EhNG9LmdheQFmAg6ozdrgU%3D), which is available from the public records at the companies house database: https://beta.companieshouse.gov.uk/company/04097991/filing-history

Summary: 
No change in tangible assets from 2014-2015, meaning no new equipment has been purchased.
SPR is holding more cash than it has previously (about 15,000 pounds compared to 5,000 pounds).
Most importantly, it has paid off a portion of its long term debt, going from 240,000 to 195,000 pounds.

It currently has negative net assets of 185,000 pounds, less than the 235,000 as of the same date in 2014.  With only the balance sheet and no income statement, it is impossible to deduce where the cash to pay off the long term debt came from or if the debt was perhaps forgiven instead.  Investment can be ruled out however, as the number of outstanding shares has not changed since 2014.   

Previous posts on this subject are linked below:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1394575#msg1394575
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396231#msg1396231
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396346#msg1396346
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396365#msg1396365

Interesting.  The fact that SPR is paying off, and reducing debt is positive, as well as raising the amount of cash  is positive.   It shows that he intends to keep SPR as a viable company.

Out of curiosity (from your report), do you see any evidence of:

1) SPR having any employees other than Roger Shawyer?

2) SPR being associated with any companies in any projects?

3) SPR receiving any recent royalties from licensees?

4) SPR receiving any recent loans?

Any expenditures needed to make the superconducting flying vehicles a reality? (my understanding is NO, since you write " no new equipment has been purchased. SPR is holding more cash than it has previously (about 15,000 pounds compared to 5,000 pounds").

Besides part of the loan being forgone, perhaps it is being paid off by one of the owners in lieu of a salary?. Concerning paying off debt, under UK corporate tax law, could an owner of a small company inject cash into a privately held company to shelter income taxes at the individual level and shift them to the company level, by paying off corporate debt? 

Is the CEO/Manager of SPR receiving a salary? Or is the salary being forgone?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/21/2015 07:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418542#msg1418542">Quote from: Rodal on 08/21/2015 06:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418541#msg1418541">Quote from: wallofwolfstreet on 08/21/2015 06:34 PM</a>
An update on the finances of SPR.  The information presented in the following is current as of March 31st 2015.

Here is the most recent balance sheet (https://s3-eu-west-1.amazonaws.com/document-api-images-prod/docs/bzrCMmEtGgloc74n9a4tvKWRCgx50t96nhrU4CUZZZY/application-pdf?AWSAccessKeyId=ASIAIT35MGBV6PXVZWUA&Expires=1440180826&Signature=jDDJtNAaibcXN3PqaAMbPk6Gnyc%3D&x-amz-security-token=AQoDYXdzEKn%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEa4AP6wl8hym2jxstO%2BQzP8zKh4WjgZaxQQi%2BEX1Ta2i0gcYIEcZizfW5q6k2UvY%2Bamu1P22%2FqnF6fESRXsu1RhOIGxZ%2FkI5jej8h8u0xly0%2B3JvGCRbFI0p9KGvtnZX81DSe71y5kDg0QWAS4dTzi6WzlHccLP5v%2Br1P1mpUqBLqbk08Xeec4ghnSPwCwEhwPEPaXT3YsZpHCFwxpS1wmWJ23GG41HfVcr9%2B966DbT%2FDI6TZCo3EhmSgjdrJlLNM%2F9obiRhQA5Bwg%2BMd49gB8ktZGHeB44aDfitnZvMIUyawl1cmBSr581tTDO7HkJhwLSUGujObd32xLRDTSGa4c%2Bnhx4XahUI%2FxPS75NcKLhre55vkt29Bi02bgwmkrkwdtonU%2FFglu1Rbg7daiN74XUMVtlXHlzrEXXicFdu8w1mK9S0%2BgsrzRkacHWpySNhuHwtOgZgLw52sDpriY5TMU9KCOgk81nfscdgOLJPrGqs6XWMx8IPODKl0WyHusXfpe4qmTR2tmOyqlFgMS2%2BKc4SpoweqWAQ43YtU3T6hVLjXLz7LOjOm6yvu4EB3HV1eN6YJESK3XM00RNtu41QuRibiI%2BlQIDInqKFWhInFWrr3zA3uqAH2B9EhNG9LmdheQFmAg6ozdrgU%3D), which is available from the public records at the companies house database: https://beta.companieshouse.gov.uk/company/04097991/filing-history

Summary: 
No change in tangible assets from 2014-2015, meaning no new equipment has been purchased.
SPR is holding more cash than it has previously (about 15,000 pounds compared to 5,000 pounds).
Most importantly, it has paid off a portion of its long term debt, going from 240,000 to 195,000 pounds.

It currently has negative net assets of 185,000 pounds, less than the 235,000 as of the same date in 2014.  With only the balance sheet and no income statement, it is impossible to deduce where the cash to pay off the long term debt came from or if the debt was perhaps forgiven instead.  Investment can be ruled out however, as the number of outstanding shares has not changed since 2014.   

Previous posts on this subject are linked below:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1394575#msg1394575
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396231#msg1396231
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396346#msg1396346
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396365#msg1396365

Interesting.  The fact that SPR is paying off, and reducing debt is positive, as well as raising the amount of cash  is positive.   It shows that he intends to keep SPR as a viable company.

Do you see any evidence of:

1) SPR having any employees other than Roger Shawyer?

2) SPR being associated with any companies in any projects?

3) SPR receiving any recent royalties from licensees?

4) SPR receiving any recent loans?

Any expenditures needed to make the superconducting flying vehicles a reality? (my understanding is NO, since you write " no new equipment has been purchased. SPR is holding more cash than it has previously (about 15,000 pounds compared to 5,000 pounds").

Under UK corporate tax law, could an owner of a small company inject cash into a privately held company to shelter income taxes at the individual level and shift them to the company level, by paying off corporate debt?
You have to root for small businesses everywhere. One fell swoop from a wealthy competitor can destroy hard-earned businesses, some family operated. This is nothing new as the Robber Barons around the turn of the 20th century, crushed many. Like them or not, small companies are the lifeblood of innovation.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/21/2015 07:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418547#msg1418547">Quote from: rfmwguy on 08/21/2015 07:01 PM</a>
...You have to root for small businesses everywhere. One fell swoop from a wealthy competitor can destroy hard-earned businesses, some family operated. This is nothing new as the Robber Barons around the turn of the 20th century, crushed many. Like them or not, small companies are the lifeblood of innovation.
Yes, I certainly root for small businesses everywhere.  Viva entrepreneurship :)

(abb88470a54d40f7697f1581ec02d51e.jpg)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 08/21/2015 07:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418542#msg1418542">Quote from: Rodal on 08/21/2015 06:38 PM</a>
Do you see any evidence of:

1) SPR having any employee other than Roger Shawyer?

2) SPR being associated with any companies in any projects?

3) SPR receiving any recent royalties from licensees?

4) SPR receiving any recent investments?

5) SPR receiving any recent loans?

Do you see anything on these reports concerning SPR efforts nowadays beyond Shawyer himself?
Any expenditures needed to make the superconducting flying vehicles a reality? Or any income showing license royalties?

With balance sheets alone, it is impossible to give definitive answers because it is impossible to determine exactly how different values moved between different accounts.  That said, with a company like SPR that presents an exceptionally simple balance sheet, and with multiple years of filing history, it is possible to answer your questions.  I highlight that this analysis relies on my opinion  as someone who has done this sort of work before and therefore relies on my own biases.  I welcome other opinions, especially someone like @mittlehauser who probably has more experience in the area of forensic accounting than I.

To answer your questions:

1)  SPR most definitely has no employees at the moment, and I highly doubt it has ever had any employees.  This is because:
    a)  All of the recent filing history has seen negligible change in any of the accounts, leading me to believe it has been inactive as of recent. 
    b)  When SPR had money, the perceived cash flows were to small and unsteady to indicate any person was employed there.

2)  Impossible to tell from the balance sheets; only thing that can be concluded is that if SPR has any such projects, it is not paid for it's involvement.

3)  No licensing royalties (in general this can not be determined from a balance sheet, but it is possible to deduce this in a simple balance sheet by examining changes in accounts over time).

4)  It has definitely received no recent investments.

5)  It has most likey received no recent loans (technically possible that it paid off all 240,000 of its long term credit then took out 195,000 in new long term debt, giving the appearance of only paying off a portion).

Quote
Do you see anything on these reports concerning SPR efforts nowadays beyond Shawyer himself?
Any expenditures needed to make the superconducting flying vehicles a reality? Or any income showing license royalties?

In my opinion and from my experience, I would say it is exceptionally unlikely SPR has involvement with any external business or is brining on any of the type of employees necessary to accomplish what it has claimed it is working on.  There is no such thing as the "SPR team", it really only is Shawyer.   

The fact that their is zero change in the tangible asset account tells you everything you need to know about the company's activity: companies that haven't bought anything in the last few years probably aren't very close to the successful completion of a superconducting drone. 

Quote
Concerning paying off debt, under UK corporate tax law, could an owner of a small company inject cash into a privately held company to shelter income taxes at the individual level and shift them to the company level, by paying off corporate debt?
 

I can't say for certain, but it's a good question.  I imagined thats where the recent cash inflow had come from.           

Quote
Is the CEO/Manager of SPR receiving a salary? Or is the salary being forgone?

Shawyer (in his capacity as CEO/Manager) has forgone his salary for the last three years as evidenced by the stability of the accounts and as explicitly remarked to me the by TheTraveller, so I presume Shawyer told him as much.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/21/2015 07:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418551#msg1418551">Quote from: Rodal on 08/21/2015 07:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418547#msg1418547">Quote from: rfmwguy on 08/21/2015 07:01 PM</a>
...You have to root for small businesses everywhere. One fell swoop from a wealthy competitor can destroy hard-earned businesses, some family operated. This is nothing new as the Robber Barons around the turn of the 20th century, crushed many. Like them or not, small companies are the lifeblood of innovation.
Yes, I certainly root for small businesses everywhere.  Viva entrepreneurship :)

(abb88470a54d40f7697f1581ec02d51e.jpg)
Where there is a will there is a way. I've done it three times with businesses, from nothing to something.

Back to number crunching and lurking once in awhile.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/21/2015 07:41 PM
@Dr. Rodal and others

In reference to Dr. Rodal's post here:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516

Is it possible that at this stage of actual EM Drive builds and their resulting test data ("In the public domain"). That computer based modeling might not yet include all required factors as input data to produce accurate estimates in their output data? Of all classical physics theories which could be involved, prove outside classical theories are involved or even if there are combinations of both currently taking place.

If somehow this becomes more apparent ("In the soon to be near future") that current computer modeling can't currently accurately account for the total results when those specifications are used for actual EM Drive builds. Then what's next?

Should things like internal photography and video inside cavities be used, magnetic fields and other recording and sensing devices be used in the future, during the testing of EM Drive builds?

I would like to hear what others suggested plan B's are out there to be considered if and when current computer models fail miserably to make accurate estimates. I would think others would as well.

Would you mostly all have similar plan B suggestions?

Especially with new EM Drive builds about to prove or disprove the accuracy of current computer models being used as being reasonably solid or in need of some major "Code changes" that might not even have the required mathematical formulas yet to be able to implement those "Code changes".

Don
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/21/2015 07:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418541#msg1418541">Quote from: wallofwolfstreet on 08/21/2015 06:34 PM</a>
An update on the finances of SPR.  The information presented in the following is current as of March 31st 2015.

Here is the most recent balance sheet (https://s3-eu-west-1.amazonaws.com/document-api-images-prod/docs/bzrCMmEtGgloc74n9a4tvKWRCgx50t96nhrU4CUZZZY/application-pdf?AWSAccessKeyId=ASIAIT35MGBV6PXVZWUA&Expires=1440180826&Signature=jDDJtNAaibcXN3PqaAMbPk6Gnyc%3D&x-amz-security-token=AQoDYXdzEKn%2F%2F%2F%2F%2F%2F%2F%2F%2F%2FwEa4AP6wl8hym2jxstO%2BQzP8zKh4WjgZaxQQi%2BEX1Ta2i0gcYIEcZizfW5q6k2UvY%2Bamu1P22%2FqnF6fESRXsu1RhOIGxZ%2FkI5jej8h8u0xly0%2B3JvGCRbFI0p9KGvtnZX81DSe71y5kDg0QWAS4dTzi6WzlHccLP5v%2Br1P1mpUqBLqbk08Xeec4ghnSPwCwEhwPEPaXT3YsZpHCFwxpS1wmWJ23GG41HfVcr9%2B966DbT%2FDI6TZCo3EhmSgjdrJlLNM%2F9obiRhQA5Bwg%2BMd49gB8ktZGHeB44aDfitnZvMIUyawl1cmBSr581tTDO7HkJhwLSUGujObd32xLRDTSGa4c%2Bnhx4XahUI%2FxPS75NcKLhre55vkt29Bi02bgwmkrkwdtonU%2FFglu1Rbg7daiN74XUMVtlXHlzrEXXicFdu8w1mK9S0%2BgsrzRkacHWpySNhuHwtOgZgLw52sDpriY5TMU9KCOgk81nfscdgOLJPrGqs6XWMx8IPODKl0WyHusXfpe4qmTR2tmOyqlFgMS2%2BKc4SpoweqWAQ43YtU3T6hVLjXLz7LOjOm6yvu4EB3HV1eN6YJESK3XM00RNtu41QuRibiI%2BlQIDInqKFWhInFWrr3zA3uqAH2B9EhNG9LmdheQFmAg6ozdrgU%3D), which is available from the public records at the companies house database: https://beta.companieshouse.gov.uk/company/04097991/filing-history

Summary: 
No change in tangible assets from 2014-2015, meaning no new equipment has been purchased.
SPR is holding more cash than it has previously (about 15,000 pounds compared to 5,000 pounds).
Most importantly, it has paid off a portion of its long term debt, going from 240,000 to 195,000 pounds.

It currently has negative net assets of 185,000 pounds, less than the 235,000 as of the same date in 2014.  With only the balance sheet and no income statement, it is impossible to deduce where the cash to pay off the long term debt came from or if the debt was perhaps forgiven instead.  Investment can be ruled out however, as the number of outstanding shares has not changed since 2014.   

Previous posts on this subject are linked below:
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1394575#msg1394575
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396231#msg1396231
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396346#msg1396346
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1396365#msg1396365

If they are now being financed by an arm of somebody's DOD for this alleged drone of their's and if that's coming from a black budget then nothing will appear through the books here. In fact when dealing with such contracts I would argue such conventional analysis is not all that useful. Especially if this is more than likely being put through a specially created & separate shell corporation, which unless you know the name of you will not get anywhere with & even then I'd doubt you'd find much. Black budget accounting is specifically designed to be invisible as it possible can be to defeat such enquiries.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 08/21/2015 08:04 PM
Dr. Rodal,

I have been watching your and aero's work very closely, and daring risking to say something stupid due to my lack of knowledge, it seems you are on the brink of something momentous.

Because, if I understand what you are saying, you seem to be implying that by using purely classical physics in the form of Maxwell's equations and what the Meep program can process and calculate, there is an actual asymmetry of forces emerging inside the truncated cone-shaped resonating microwave cavity (aka frustum), with the calculated geometries, frequencies and antenna position (near the big base).

It seems that the model also shows that forces do cancel out when the antenna is placed close to the small base, something that we didn't know before, and that seems to contradict experimental data showing thrust in either case (probably because we are mixing up spurious error sources with the real force signature).

But the biggest news, at least for me, is that the classical calculations you and aero made falsify Greg Egan's model (the best critical model so far) saying that every force inside the Emdrive cancels out to zero, as the classical interpretation would expect, because we do expect that no device can propel itself in space without the application of the generally accepted forms of action/reaction principle, either by expelling propellant or reacting against an external field.

That such a thing may be possible at all and calculated using only classical physics is an astounding result indeed. And I understand why you would certainly like to have experimental confirmation of its validity, because such a result, if confirmed,  would certainly rock our understanding of physics, where such a thing arising from purely classical formulas and their application is a completely unexpected result.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/21/2015 09:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418569#msg1418569">Quote from: tchernik on 08/21/2015 08:04 PM</a>
Dr. Rodal,

I have been watching your and aero's work very closely, and daring risking to say something stupid due to my lack of knowledge, it seems you are on the brink of something momentous.

Because, if I understand what you are saying, you seem to be implying that by using purely classical physics in the form of Maxwell's equations and what the Meep program can process and calculate, there is an actual asymmetry of forces emerging inside the truncated cone-shaped resonating microwave cavity (aka frustum), with the calculated geometries, frequencies and antenna position (near the big base).

It seems that the model also shows that forces do cancel out when the antenna is placed close to the small base, something that we didn't know before, and that seems to contradict experimental data showing thrust in either case (probably because we are mixing up spurious error sources with the real force signature).

But the biggest news, at least for me, is that the classical calculations you and aero made falsify Greg Egan's model (the best critical model so far) saying that every force inside the Emdrive cancels out to zero, as the classical interpretation would expect, because we do expect that no device can propel itself in space without the application of the generally accepted forms of action/reaction principle, either by expelling propellant or reacting against an external field.

That such a thing may be possible at all and calculated using only classical physics is an astounding result indeed. And I understand why you would certainly like to have experimental confirmation of its validity, because such a result, if confirmed,  would certainly rock our understanding of physics, where such a thing arising from purely classical formulas and their application is a completely unexpected result.

I read your understanding as correct for case (b), (antenna near the big base), but my classical physics interpretation is that it must cancel out through the RF and power feed if the RF feed and power come from a stationary location that cannot move.  Therefore deltaMass and frobnicat must be given credit for emphasizing that a true test of the EM Drive must contain all components together in one mobile package.  TheTraveller and the Aachen team must be given credit for designing such experiments where everything will be together in one mobile package.   Case (a) antenna at small end is also interesting as classical physics would predict no forces for that case.  Thus, I hope that rfmwguy and Shell will conduct experiments with the RF feed in separate tests being near the small end and near the big end to see how it compares with the Meep results :)

It would be most interesting for TheTraveller to conduct separate experiments with A) the antenna near the big base and separately B) with the antenna near the small base to see what difference it makes on his experiment

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Blaine on 08/21/2015 09:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418576#msg1418576">Quote from: Rodal on 08/21/2015 09:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418569#msg1418569">Quote from: tchernik on 08/21/2015 08:04 PM</a>
Dr. Rodal,

I have been watching your and aero's work very closely, and daring risking to say something stupid due to my lack of knowledge, it seems you are on the brink of something momentous.

Because, if I understand what you are saying, you seem to be implying that by using purely classical physics in the form of Maxwell's equations and what the Meep program can process and calculate, there is an actual asymmetry of forces emerging inside the truncated cone-shaped resonating microwave cavity (aka frustum), with the calculated geometries, frequencies and antenna position (near the big base).

It seems that the model also shows that forces do cancel out when the antenna is placed close to the small base, something that we didn't know before, and that seems to contradict experimental data showing thrust in either case (probably because we are mixing up spurious error sources with the real force signature).

But the biggest news, at least for me, is that the classical calculations you and aero made falsify Greg Egan's model (the best critical model so far) saying that every force inside the Emdrive cancels out to zero, as the classical interpretation would expect, because we do expect that no device can propel itself in space without the application of the generally accepted forms of action/reaction principle, either by expelling propellant or reacting against an external field.

That such a thing may be possible at all and calculated using only classical physics is an astounding result indeed. And I understand why you would certainly like to have experimental confirmation of its validity, because such a result, if confirmed,  would certainly rock our understanding of physics, where such a thing arising from purely classical formulas and their application is a completely unexpected result.

I read your understanding as correct for case (b), (antenna near the big base), but my classical physics interpretation is that it must cancel out through the RF and power feed if the RF feed and power come from a stationary location that cannot move.  Therefore deltaMass and frobnicat must be given credit for emphasizing that a true test of the EM Drive must contain all components together in one mobile package.  TheTraveller and the Aachen team must be given credit for designing such experiments where everything will be together in one mobile package.   Case (a) antenna at small end is also interesting as classical physics would predict no forces for that case.  Thus, I hope that rfmwguy and Shell will conduct experiments with the RF feed in separate tests being near the small end and near the big end to see how it compares with the Meep results :)

It would be most interesting for TheTraveller to conduct experiments with the antenna near the big base and with the antenna near the small base to see what difference it makes on his experiment

So, like a rail gun, the "extra" force might be going to the RF or power source of the RF?  Interesting. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 08/21/2015 09:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418564#msg1418564">Quote from: Star One on 08/21/2015 07:43 PM</a>
If they are now being financed by an arm of somebody's DOD for this alleged drone of their's and if that's coming from a black budget then nothing will appear through the books here. In fact when dealing with such contracts I would argue such conventional analysis is not all that useful. Especially if this is more than likely being put through a specially created & separate shell corporation, which unless you know the name of you will not get anywhere with & even then I'd doubt you'd find much. Black budget accounting is specifically designed to be invisible as it possible can be to defeat such enquiries.

Fair point.  I appreciate the perspective.

Personally, I very much doubt that they are being financed by any branch of any defense organization however.
I mean; Shawyer is actively disclosing his plans and designs, as well as previous experimental work to a man (TheTraveller) who just emailed him out of the blue.  What's more, he's given permission for TheTraveller to share all that information on multiple public forums (NSF, reddit). 

Is it really likely that a mysterious organization is going to great lengths (or any lengths for that matter) to obscure the financials of SPR, knowing that SPRs one and only employee has openly disclosed the development of their black project to the public at large?   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/21/2015 09:52 PM
Anyone see a trend where experiments with the frustum oriented vertically seem to have more thrust than horizontal ones? There isn't much to go on yet. I remember that from the Romanian guy's test (he also moved the magnetron at the same time though.) Were the Chinese tests all vertical? Something to keep an eye on.

Shawyer's theory says the frustum needs an acceleration first in order to get it going. Why not acceleration due to gravity?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Blaine on 08/21/2015 09:55 PM
Okay, so, lets say for a moment that the force experienced needs a rf and rf power supply securely in place.  Now, lets say that we place it on a Hendo.  Technically would the force experienced be transferred into the Lorentz forces, playing a role in how the hover board hovers? Or perhaps this would do something even crazier and the EmDrive would get a boost.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/21/2015 10:02 PM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418587#msg1418587">Quote from: wallofwolfstreet on 08/21/2015 09:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418564#msg1418564">Quote from: Star One on 08/21/2015 07:43 PM</a>
If they are now being financed by an arm of somebody's DOD for this alleged drone of their's and if that's coming from a black budget then nothing will appear through the books here. In fact when dealing with such contracts I would argue such conventional analysis is not all that useful. Especially if this is more than likely being put through a specially created & separate shell corporation, which unless you know the name of you will not get anywhere with & even then I'd doubt you'd find much. Black budget accounting is specifically designed to be invisible as it possible can be to defeat such enquiries.

Fair point.  I appreciate the perspective.

Personally, I very much doubt that they are being financed by any branch of any defense organization however.
I mean; Shawyer is actively disclosing his plans and designs, as well as previous experimental work to a man (TheTraveller) who just emailed him out of the blue.  What's more, he's given permission for TheTraveller to share all that information on multiple public forums (NSF, reddit). 

Is it really likely that a mysterious organization is going to great lengths (or any lengths for that matter) to obscure the financials of SPR, knowing that SPRs one and only employee has openly disclosed the development of their black project to the public at large?

Only The Traveller can really answer that as it's a very good question.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/21/2015 10:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418588#msg1418588">Quote from: Mulletron on 08/21/2015 09:52 PM</a>
Anyone see a trend where experiments with the frustum oriented vertically seem to have more thrust than horizontal ones? There isn't much to go on yet. I remember that from the Romanian guy's test (he also moved the magnetron at the same time though.) Were the Chinese tests all vertical? Something to keep an eye on.
...
Well, that might be correlated to the magnetic field of the Earth or some interference with the AC, still  EW (and Tajmar) vacuum chamber seems to be a pretty good magnetic shield as a whole.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 08/21/2015 10:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418556#msg1418556">Quote from: wallofwolfstreet on 08/21/2015 07:16 PM</a>
{snip}
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418542#msg1418542">Quote from: Rodal on 08/21/2015 06:38 PM</a>

Is the CEO/Manager of SPR receiving a salary? Or is the salary being forgone?

Shawyer (in his capacity as CEO/Manager) has forgone his salary for the last three years as evidenced by the stability of the accounts and as explicitly remarked to me the by TheTraveller, so I presume Shawyer told him as much.

In 2014/5 SPR received demands for £2,525 in Taxation and Social Security plus £1,086 to other creditors.
In 2013/4 SPR made no such payments.

So either the British Government or Berkshire County Council did something. This may be a side effect of the reduction in the long term loans.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/21/2015 10:58 PM
Fascinating reading about the history of the aether, its abandonment and reintroduction as "new aether" by Einstein.
https://en.wikipedia.org/wiki/Luminiferous_aether#Einstein.27s_views_on_the_aether


While reading up on resonator experiments concerning the aether, I found this which is thought-provoking:

http://vixra.org/pdf/1009.0057v3.pdf
Why over 30 years absolute motion was not detected in Michelson-type experiments
with resonators
V.V. Demjanov

He's basically saying all the negative results were wrong.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/21/2015 11:55 PM
@SeeShells,

I've a little problem modelling your Crazy-Eddie thruster. (I'm abbreviating it to a C-E model to keep names short.)

1) Where do I start with the location of the small base reflecting surface - I know it moves?
2) I see small diameters of 0.16 meters and on the graphic, 0.1603 - what is up with that?
3) Where really is the large base reflecting surface?

Here is an image showing my progress so far. But the C-E cavity is another big one so I'm forced to reduce resolution to keep the run times down. Once I add width to accommodate waveguide feeds, we'll need some volunteers to make runs of any decent duration.

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 01:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418618#msg1418618">Quote from: aero on 08/21/2015 11:55 PM</a>
@SeeShells,

I've a little problem modelling your Crazy-Eddie thruster. (I'm abbreviating it to a C-E model to keep names short.)

1) Where do I start with the location of the small base reflecting surface - I know it moves?
2) I see small diameters of 0.16 meters and on the graphic, 0.1603 - what is up with that?
3) Where really is the large base reflecting surface?

Here is an image showing my progress so far. But the C-E cavity is another big one so I'm forced to reduce resolution to keep the run times down. Once I add width to accommodate waveguide feeds, we'll need some volunteers to make runs of any decent duration.

aero
Ok I understand. I'm still laying out the frustum and don't have a full layout.

The large plate top starts right at the sidewall boundary up from the bottom .0205m .

The fulcrum cavity length from the large center endplate to the small endplate ends within the tuning cavity tube and is up from the large center plate .2620m and stops in the tuning chamber 0.0376m.

You need to take off the straight section at the bottom just like all the others. The top is fine as long as the cavity in the tuning tube is 0.0376m before it ends for a total of 0.2620m cavity length.

Still modeling and rechecking.

Thanks

Shell


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/22/2015 02:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418627#msg1418627">Quote from: SeeShells on 08/22/2015 01:14 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418618#msg1418618">Quote from: aero on 08/21/2015 11:55 PM</a>
@SeeShells,

I've a little problem modelling your Crazy-Eddie thruster. (I'm abbreviating it to a C-E model to keep names short.)

1) Where do I start with the location of the small base reflecting surface - I know it moves?
2) I see small diameters of 0.16 meters and on the graphic, 0.1603 - what is up with that?
3) Where really is the large base reflecting surface?

Here is an image showing my progress so far. But the C-E cavity is another big one so I'm forced to reduce resolution to keep the run times down. Once I add width to accommodate waveguide feeds, we'll need some volunteers to make runs of any decent duration.

aero
Ok I understand. I'm still laying out the frustum and don't have a full layout.

The large plate top starts right at the sidewall boundary up from the bottom .0205m .

The fulcrum cavity length from the large center endplate to the small endplate ends within the tuning cavity tube and is up from the large center plate .2620m and stops in the tuning chamber 0.0376m.

You need to take off the straight section at the bottom just like all the others. The top is fine as long as the cavity in the tuning tube is 0.0376m before it ends for a total of 0.2620m cavity length.

Still modeling and rechecking.

Thanks

Shell

So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 03:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418627#msg1418627">Quote from: SeeShells on 08/22/2015 01:14 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418618#msg1418618">Quote from: aero on 08/21/2015 11:55 PM</a>
@SeeShells,

I've a little problem modelling your Crazy-Eddie thruster. (I'm abbreviating it to a C-E model to keep names short.)

1) Where do I start with the location of the small base reflecting surface - I know it moves?
2) I see small diameters of 0.16 meters and on the graphic, 0.1603 - what is up with that?
3) Where really is the large base reflecting surface?

Here is an image showing my progress so far. But the C-E cavity is another big one so I'm forced to reduce resolution to keep the run times down. Once I add width to accommodate waveguide feeds, we'll need some volunteers to make runs of any decent duration.

aero
Ok I understand. I'm still laying out the frustum and don't have a full layout.

The large plate top starts right at the sidewall boundary up from the bottom .0205m .

The fulcrum cavity length from the large center endplate to the small endplate ends within the tuning cavity tube and is up from the large center plate .2620m and stops in the tuning chamber 0.0376m.

You need to take off the straight section at the bottom just like all the others. The top is fine as long as the cavity in the tuning tube is 0.0376m before it ends for a total of 0.2620m cavity length.

Still modeling and rechecking.

Thanks

Shell

So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/22/2015 03:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418514#msg1418514">Quote from: kencolangelo on 08/21/2015 05:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418282#msg1418282">Quote from: SeeShells on 08/20/2015 10:59 PM</a>
Flat ends. Try as I might, I cannot get a uniform curve on an english wheel, miss my old tool room lathe.
Shell
Maybe try hydroforming? Works for fuel tanks. Looks fun anyway.
With Copper it is very easy to raise a simple uniform bowl shape.   All you need is a stump with a rounded depression, and a hammer with a face that is smooth and hemispherical.   A few heat cycles are needed to soften the work-hardened Copper.   It takes a lot of hammering but the natural inclination of the Copper is to move into a bowl shape.   I used to do a lot of that before I got into the software racket.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/22/2015 04:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

But I thought you were going to use silver plated ceramic for the end plates? I liked that idea much better than copper end plates because of my hypothesis that thrust may be generated by tunnelling evanescent waves. A thin silver plate on ceramic would have a lot lower barrier height than copper end plates, although 30 um might be more than I'd like to see.

One thing that bugs me about my idea is that the math seems to be readily available to check for momentum from tunnelling evanescent waves, but I don't have the knowledge to apply it.

But back to the C-E drive, the small end plate cannot be the same diameter as the inner diameter of the tuning tube. You may try for the same size but it won't move if it is wedged in tightly and you want it to move. What is your expected tolerance on the two diameters? Millimetres? Hundreds of micrometers? Tens of micrometers? Evanescent waves will escape through this gap and we want to see them.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 04:28 AM
Fortunately, sneaky attempts to sneak in a sneaky photon rocket will not affect the outcome  ;D
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 04:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

But I thought you were going to use silver plated ceramic for the end plates? I liked that idea much better than copper end plates because of my hypothesis that thrust may be generated by tunnelling evanescent waves. A thin silver plate on ceramic would have a lot lower barrier height than copper end plates, although 30 um might be more than I'd like to see.

One thing that bugs me about my idea is that the math seems to be readily available to check for momentum from tunnelling evanescent waves, but I don't have the knowledge to apply it.

But back to the C-E drive, the small end plate cannot be the same diameter as the inner diameter of the tuning tube. You may try for the same size but it won't move if it is wedged in tightly and you want it to move. What is your expected tolerance on the two diameters? Millimetres? Hundreds of micrometers? Tens of micrometers? Evanescent waves will escape through this gap and we want to see them.

I'm looking at about a .0125mm gap. I've ordered 2 plates. The second one I'll modify for evanescent wave actions with a set pattern in the silver for just them and set a conductive seal between the plate and sidewalls. I just would like to see what meep does in the modes with the antennas you selected and not too worried about them this run.

Is that ok ?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/22/2015 04:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418606#msg1418606">Quote from: Mulletron on 08/21/2015 10:58 PM</a>
Fascinating reading about the history of the aether, its abandonment and reintroduction as "new aether" by Einstein.
https://en.wikipedia.org/wiki/Luminiferous_aether#Einstein.27s_views_on_the_aether


While reading up on resonator experiments concerning the aether, I found this which is thought-provoking:

http://vixra.org/pdf/1009.0057v3.pdf
Why over 30 years absolute motion was not detected in Michelson-type experiments
with resonators
V.V. Demjanov

He's basically saying all the negative results were wrong.

A strong advocate of the anisotropy of the speed of light  (in material medium) revealed by the analysis of the Michelson-Morley experience test results,  is the Australian phycisist  Reginald Cahill. A simple research on this name in arxiv.org will report the articles where he adress the subject. Reginald Cahill  has the same conclusion than Demjanov of an apparent aether speed of 500 km/s with respect to the earth reference where anisotropy is detected.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 05:23 AM
Please save us time on this. WikiP reports delta-c/c <= 10-17 from the most recent measurements. Is this the value taken by your two guys?
viXra is just about the last place to go for "information", btw.

OK, I peeked. This from arXiv critiques your sources
http://arxiv.org/abs/1404.6095

Diurnal and seasonal variations in CO2 is the likely culprit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/22/2015 05:32 AM
@SeeShell -

Yea, that's Ok. Meep on my computer can't resolve a 0.0125 mm gap. I'll go about looking for a resonance in the C-E frustum I have modelled. The inside faces of the ends are the correct distance apart, ckhigh = 0.26199999999999996 meters. I assume that's close enough  :)  So I guess the model is correct. I can't think of another way to fit your numbers together and still get the right length. Well, I could move both ends, but that would violate your rule on the big end plate location.

So, I'm ready to chase resonance.  Tomorrow.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/22/2015 07:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418658#msg1418658">Quote from: deltaMass on 08/22/2015 05:23 AM</a>
Please save us time on this. WikiP reports delta-c/c <= 10-17 from the most recent measurements. Is this the value taken by your two guys?
viXra is just about the last place to go for "information", btw.

OK, I peeked. This from arXiv critiques your sources
http://arxiv.org/abs/1404.6095

Diurnal and seasonal variations in CO2 is the likely culprit.

The following article from Reginald Cahill (http://vixra.org/abs/1504.0125 (http://vixra.org/abs/1504.0125)) lists several physical experiences  concluding to the existence of a kind of absolute reference frame : "Review of Experiments that Contradict Special Relativity and Support Neo-Lorentz Relativity: Latest Technique to Detect Dynamical Space Using Quantum Detectors"

In his article that you refer to, ("A criticism of ”gas mode ”reinterpretations of the Michelson-Morley and similar experiments."), Daniel Shanahan far from disputing the thesis of Reginald Cahill on the existence of an absolute frame, writes in support to it : "However, it is also suggested here that whether or not the absolute frame urged by these investigators is detectable, there exist compelling reasons for considering the alternative Lorentzian approach to relativity that did suppose such a frame".

Now on the analysis of the speed of light in material medium, it is really strange that Daniel Shanahan call it "Reduced phase velocity V of light". For me this speed is a real speed (with energy transport) and not a phase speed which can be as great as we want. Moreover the Maxwell equations (which are fully Lorentz transformation compatible) give a clear and invariant status to the light speed in a material medium as soon as this medium is characterized by well defined permittivity and permeability.  Do you suggest that permittivity and permeability depend on the speed of the observer who measure them ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 09:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

But I thought you were going to use silver plated ceramic for the end plates? I liked that idea much better than copper end plates because of my hypothesis that thrust may be generated by tunnelling evanescent waves. A thin silver plate on ceramic would have a lot lower barrier height than copper end plates, although 30 um might be more than I'd like to see.

One thing that bugs me about my idea is that the math seems to be readily available to check for momentum from tunnelling evanescent waves, but I don't have the knowledge to apply it.

But back to the C-E drive, the small end plate cannot be the same diameter as the inner diameter of the tuning tube. You may try for the same size but it won't move if it is wedged in tightly and you want it to move. What is your expected tolerance on the two diameters? Millimetres? Hundreds of micrometers? Tens of micrometers? Evanescent waves will escape through this gap and we want to see them.

I'm looking at about a .0125mm gap. I've ordered 2 plates. The second one I'll modify for evanescent wave actions with a set pattern in the silver for just them and set a conductive seal between the plate and sidewalls. I just would like to see what meep does in the modes with the antennas you selected and not too worried about them this run.

Is that ok ?

Shell

Thoughts to the gap...

Shell, is your favorite target mode still TE012? If yes the field strength(E) for this mode tend to zero near the "edge" of frustum and endplate. It is zero in the corner. There will be also no current flow between the frustum and the plate.
So if the gap is small its not "visible" from the viewpoint of this mode.

For some other mode shapes the gap can work as a slot antenna, it can radiate, not in the sense of evanescent waves.. The most interesting point is the length of the slot and thats the circumference in your case(not only the width of the gap is important).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/22/2015 10:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418664#msg1418664">Quote from: Mezzenile on 08/22/2015 07:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418658#msg1418658">Quote from: deltaMass on 08/22/2015 05:23 AM</a>
Please save us time on this. WikiP reports delta-c/c <= 10-17 from the most recent measurements. Is this the value taken by your two guys?
viXra is just about the last place to go for "information", btw.

OK, I peeked. This from arXiv critiques your sources
http://arxiv.org/abs/1404.6095

Diurnal and seasonal variations in CO2 is the likely culprit.

The following article from Reginald Cahill (http://vixra.org/abs/1504.0125 (http://vixra.org/abs/1504.0125)) lists several physical experiences  concluding to the existence of a kind of absolute reference frame : "Review of Experiments that Contradict Special Relativity and Support Neo-Lorentz Relativity: Latest Technique to Detect Dynamical Space Using Quantum Detectors"

In his article that you refer to, ("A criticism of ”gas mode ”reinterpretations of the Michelson-Morley and similar experiments."), Daniel Shanahan far from disputing the thesis of Reginald Cahill on the existence of an absolute frame, writes in support to it : "However, it is also suggested here that whether or not the absolute frame urged by these investigators is detectable, there exist compelling reasons for considering the alternative Lorentzian approach to relativity that did suppose such a frame".

Now on the analysis of the speed of light in material medium, it is really strange that Daniel Shanahan call it "Reduced phase velocity V of light". For me this speed is a real speed (with energy transport) and not a phase speed which can be as great as we want. Moreover the Maxwell equations (which are fully Lorentz transformation compatible) give a clear and invariant status to the light speed in a material medium as soon as this medium is characterized by well defined permittivity and permeability.  Do you suggest that permittivity and permeability depend on the speed of the observer who measure them ?

Moreover the relativistic drag effect invoked by  Daniel Shanahan in a medium moving with respect to the observer cannot be opposed to the experience proposed by Reginald Cahill (Michelson-Morley in material medium) as in this case the observer is at rest with the interferometer and its material medium (the drag effect is zero). So I don't see why if the experience proposed by Reginald Cahill shows a variation of speed it should not be linked to an anisotropy of the speed of light.

Conclusion : Let Reginald Cahill perform his proposed experience (as our friends are making their "silly" force measurement on EM cavity  !!) and the Oracle will tell where is the Truth !!!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 12:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675">Quote from: X_RaY on 08/22/2015 09:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

But I thought you were going to use silver plated ceramic for the end plates? I liked that idea much better than copper end plates because of my hypothesis that thrust may be generated by tunnelling evanescent waves. A thin silver plate on ceramic would have a lot lower barrier height than copper end plates, although 30 um might be more than I'd like to see.

One thing that bugs me about my idea is that the math seems to be readily available to check for momentum from tunnelling evanescent waves, but I don't have the knowledge to apply it.

But back to the C-E drive, the small end plate cannot be the same diameter as the inner diameter of the tuning tube. You may try for the same size but it won't move if it is wedged in tightly and you want it to move. What is your expected tolerance on the two diameters? Millimetres? Hundreds of micrometers? Tens of micrometers? Evanescent waves will escape through this gap and we want to see them.

I'm looking at about a .0125mm gap. I've ordered 2 plates. The second one I'll modify for evanescent wave actions with a set pattern in the silver for just them and set a conductive seal between the plate and sidewalls. I just would like to see what meep does in the modes with the antennas you selected and not too worried about them this run.

Is that ok ?

Shell

Thoughts to the gap...

Shell, is your favorite target mode still TE012? If yes the field strength(E) for this mode tend to zero near the "edge" of frustum and endplate. It is zero in the corner. There will be also no current flow between the frustum and the plate.
So if the gap is small its not "visible" from the viewpoint of this mode.

For some other mode shapes the gap can work as a slot antenna, it can radiate, not in the sense of evanescent waves.. The most interesting point is the length of the slot and thats the circumference in your case(not only the width of the gap is important).

It's easier to model in meep if it's treated as connected or a small gap which aero likes, in real life I'm going around the circumference of the plate with a beryllium copper gasket that will electrically connect to the frustum and seal the endcap but allow it to slide freely.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 12:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675">Quote from: X_RaY on 08/22/2015 09:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


Check back later, have friends over.

Shell

Thoughts to the gap...

Shell, is your favorite target mode still TE012? If yes the field strength(E) for this mode tend to zero near the "edge" of frustum and endplate. It is zero in the corner. There will be also no current flow between the frustum and the plate.
So if the gap is small its not "visible" from the viewpoint of this mode.

For some other mode shapes the gap can work as a slot antenna, it can radiate, not in the sense of evanescent waves.. The most interesting point is the length of the slot and thats the circumference in your case(not only the width of the gap is important).
This is an idea also thought of by Paul March too. Honesty I like the simplicity of the slot antenna Even though he was going for a TM010 mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 01:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675">Quote from: X_RaY on 08/22/2015 09:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


Shell

Thoughts to the gap...

Shell, is your favorite target mode still TE012? If yes the field strength(E) for this mode tend to zero near the "edge" of frustum and endplate. It is zero in the corner. There will be also no current flow between the frustum and the plate.
So if the gap is small its not "visible" from the viewpoint of this mode.

For some other mode shapes the gap can work as a slot antenna, it can radiate, not in the sense of evanescent waves.. The most interesting point is the length of the slot and thats the circumference in your case(not only the width of the gap is important).

I'm still going to pursue the TE012 mode even though it seems to be tough the gains outweigh the toughness. And it is because of the gains seen in thrust a potential red flag to persue.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 01:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418691#msg1418691">Quote from: SeeShells on 08/22/2015 12:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675">Quote from: X_RaY on 08/22/2015 09:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

But I thought you were going to use silver plated ceramic for the end plates? I liked that idea much better than copper end plates because of my hypothesis that thrust may be generated by tunnelling evanescent waves. A thin silver plate on ceramic would have a lot lower barrier height than copper end plates, although 30 um might be more than I'd like to see.

One thing that bugs me about my idea is that the math seems to be readily available to check for momentum from tunnelling evanescent waves, but I don't have the knowledge to apply it.

But back to the C-E drive, the small end plate cannot be the same diameter as the inner diameter of the tuning tube. You may try for the same size but it won't move if it is wedged in tightly and you want it to move. What is your expected tolerance on the two diameters? Millimetres? Hundreds of micrometers? Tens of micrometers? Evanescent waves will escape through this gap and we want to see them.

I'm looking at about a .0125mm gap. I've ordered 2 plates. The second one I'll modify for evanescent wave actions with a set pattern in the silver for just them and set a conductive seal between the plate and sidewalls. I just would like to see what meep does in the modes with the antennas you selected and not too worried about them this run.

Is that ok ?

Shell

Thoughts to the gap...

Shell, is your favorite target mode still TE012? If yes the field strength(E) for this mode tend to zero near the "edge" of frustum and endplate. It is zero in the corner. There will be also no current flow between the frustum and the plate.
So if the gap is small its not "visible" from the viewpoint of this mode.

For some other mode shapes the gap can work as a slot antenna, it can radiate, not in the sense of evanescent waves.. The most interesting point is the length of the slot and thats the circumference in your case(not only the width of the gap is important).

It's easier to model in meep if it's treated as connected or a small gap which aero likes, in real life I'm going around the circumference of the plate with a beryllium copper gasket that will electrically connect to the frustum and seal the endcap but allow it to slide freely.

Shell
Good plan. For all the modes which produce currents thru the gap, a good galvanic contact is necessary. While moving the plate the S-Parameter signal will look a little noisy that depends on the contact between the frustum and the plate(will be stable again after movement). The resonant frequency could be a little bit lower than calculated for a given length (MHz range, caused by longer current paths) if the metal seal is at the outer side.
For TE01p that is not the case, no noise while moving the plate.
Again its a good plan. No better idea at the moment :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/22/2015 01:18 PM
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/22/2015 01:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418269#msg1418269">Quote from: SteveD on 08/20/2015 10:24 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418130#msg1418130">Quote from: rfmwguy on 08/20/2015 07:01 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418125#msg1418125">Quote from: SeeShells on 08/20/2015 06:45 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418119#msg1418119">Quote from: rfmwguy on 08/20/2015 06:32 PM</a>
So, been thinking about a suitable lab in case further experimentation on NSF-1701 is desired. Here's a stream of consciousness list of the test gear I'd like to get my hands on (all calibrated with computer interface, RF stuff 3 GHz minimum):

(...)OK, what are we missing...hmmm

<edit> I stopped counting at $100,000
Tools to make advanced frustums wrt machine shop tools.
Good catch shell, of course...looks like my estimate doubled to about $400K total not including building.

So about the same capital cost as a gas station, plus say $250K a year in salaries and another $100K in materials/misc.  So around $1m and two years for a useful prototype (if such a thing is even possible).  That's a large grant or an average sized early stage venture capital project.  Doable, but difficult.  At around 200N/Kwh you're approaching the output of a turbojet, that's certainly interesting if it can be achieved.  Also, um if the drive doesn't pan out is there any chance the research could lead to a better way to cook a potato?

For venture capital my gut is telling me that you'd need thrust outside of the noise range, say 1N and some indication that better can be reached.  A working theory that does not violate CoE or CoM would also be helpful, as would some press releases before seeking funding.

If 1N/kW could be proven, every aerospace company on the planet would be building these.  Yes, it's that big a game-changer.   Mind you, if I understand the physics correctly, a 100% efficient unit would be 1KN/KW right?  That means currently we're only talking about a 0.1% efficiency (1N) and that would be enough to change the face of spaceflight.   Figure this thing out and the money will come at you like a firehose (my conjecture).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/22/2015 01:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417397#msg1417397">Quote from: Prunesquallor on 08/19/2015 01:03 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.

I know I'm a broken record, but IMHO there are many more uncontrollable factors in low earth orbit than in the lab, considering the minscule power available for the thruster on a cubesat.

In a 6u cubesat, we can get up to about 400W from the solar arrays and store enough to do a few KW of output for short periods (several minutes).  That avionics bus design is on my computer now (I do avionics for a living).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/22/2015 01:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

If I gave you a 3D printed form for the spherical base would that help to form it?  Unforunately I only have 11" diameter - 295 is about 11.6" - just a little too big for my new big printer, but I could do 4 identical quarters and super-glue them together... Actually I know a firm here in Baltimore that can copperplate the plastic for reasonable money - but it's probably $1K at a guess...  It would be several microns thick...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 01:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)

I'm not clear as to whether you are referring to the fact that right now you have succeeded to eliminate all drafts, air convection from your garage so that the beam is stable and the beam does not oscillate on its own or whether you are referring to damping an impulse response.  How fast does it damp out an impulse?  If there is enough friction so that it damps out the initial impulse response resulting for example from applying an extra weight, you are OK.  On the other hand if it does not damp out an initial impulse, you may still need the oil damper.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/22/2015 01:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418458#msg1418458">Quote from: rfmwguy on 08/21/2015 01:37 PM</a>
Have a favor to ask my NSF pals here...on my 2 hour guest appearance next Thursday/Friday on the digital radio show, the last hour is being left open for callers questions/comments. Rather than the general audience, I'd like NSF folks to call in. It will be fun to hear your voices and get your perspective on the concept/project whether for or against the theories out there. Also a chance to update on your own project (see-shell) ;)

Date is 8/28, call in time about 1:00 AM Pacific Daylight Time 08:00 UTC

Phone No.: (505) 796-8802
Skype: enterprisemission

Should be fun...first names or NSF nicknames only are cool.

(gulp) that's 4AM eastern - might try to do it anyway :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/22/2015 01:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418709#msg1418709">Quote from: Rodal on 08/22/2015 01:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)

I'm not clear as to whether you are referring to the fact that right now you have succeeded to eliminate all drafts, air convection from your garage so that the beam is stable and the beam does not oscillate on its own or whether you are referring to damping an impulse response.  How fast does it damp out an impulse?  If there is enough friction so that it damps out the initial impulse response resulting for example from applying an extra weight, you are OK.  On the other hand if it does not damp out an initial impulse, you may still need the oil damper.
I was surprised as well. My guess is the rigid steel wire is doing most the work, plus there is about twice the mass on the knife edges. Verticle dampening is quick, horizontal dampening takes more than twice the time, but has improved. Random airflow does not affect it as much due to the increased mass i believe. This was a real problem before. Verticle dampening of 1 g weight insertion is less than 30 seconds and almost no jitter.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 02:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)
You have me excited rfmwguy! It will be interesting to compare the two tests as we eneded up with similar setups.

Did I mention to you that you could make a tiny pinhole in a plastic business card with a hot pin (cheap and dirty pinhole lens) and put it in front of the laser to clean up the beam to get you a very small dot? I was surprised at how well this old school pinhole lens worked.

Shell

Full steam ahead rfmwguy!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 02:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418711#msg1418711">Quote from: VAXHeadroom on 08/22/2015 01:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418458#msg1418458">Quote from: rfmwguy on 08/21/2015 01:37 PM</a>
Have a favor to ask my NSF pals here...on my 2 hour guest appearance next Thursday/Friday on the digital radio show, the last hour is being left open for callers questions/comments. Rather than the general audience, I'd like NSF folks to call in. It will be fun to hear your voices and get your perspective on the concept/project whether for or against the theories out there. Also a chance to update on your own project (see-shell) ;)

Date is 8/28, call in time about 1:00 AM Pacific Daylight Time 08:00 UTC

Phone No.: (505) 796-8802
Skype: enterprisemission

Should be fun...first names or NSF nicknames only are cool.

(gulp) that's 4AM eastern - might try to do it anyway :)
Woosie. ;) Get some coffee and make it so. I'm going to be calling in.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 02:22 PM
Asked by a dear friend lurker to look this up. I had no idea this happened.
https://en.wikipedia.org/wiki/SNAP-10A
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/22/2015 02:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418714#msg1418714">Quote from: SeeShells on 08/22/2015 02:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)
You have me excited rfmwguy! It will be interesting to compare the two tests as we eneded up with similar setups.

Did I mention to you that you could make a tiny pinhole in a plastic business card with a hot pin (cheap and dirty pinhole lens) and put it in front of the laser to clean up the beam to get you a very small dot? I was surprised at how well this old school pinhole lens worked.

Shell

Full steam ahead rfmwguy!
Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 02:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418721#msg1418721">Quote from: rfmwguy on 08/22/2015 02:46 PM</a>
...Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test?  Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/22/2015 03:40 PM
http://ir.hfcas.ac.cn/bitstream/334002/12022/1/
Mode%20converters%20for%20generating%20the
%20HE%2011%20%28gaussian%20like%29%20mode
%20from%20TE%2001%20in%20a%20circular%20waveguide.pdf

In the above article, the mode coupling theory shows how  a bended circular waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half lenght and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/22/2015 05:01 PM
For those of you who want to measure in the microgram/nanonewton range . A small microbalance, might come in handy.
https://www.youtube.com/watch?v=ta7nlkI5K5g
https://www.youtube.com/watch?v=n90whRO-ypE
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/22/2015 05:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)

Can you post pictures of your device and rig?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 05:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418735#msg1418735">Quote from: Ricvil on 08/22/2015 03:40 PM</a>

In the above article, the mode coupling theory shows how  a bended circular
waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half lenght and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode?
I like this article a lot! Has some info that I suspected could happen and have been looking for.

Big Thanks!
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 06:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 07:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418767#msg1418767">Quote from: Rodal on 08/22/2015 06:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes

I just looked again and you're quite right, I mucked it up, a hard week spent running between the computer and the bathroom I guess. I'll recheck and see where I messed up as I want to know and will even use TT's and Shawyer's spread sheet to double check in the end.

Be back after a bit.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/22/2015 07:04 PM
Meep does concur.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/22/2015 07:04 PM
@TheTraveller, what happened? Are you done now? Tell us about your discoveries!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/22/2015 07:04 PM
Dr. Rodal -

Thanks very much for you post #812, which explained much pertaining to out previous discussion.

Of your logic, the only remaining thing I don't understand is why the side wall force must always be a pressure in TE modes. If I'm understanding the pictures Aero has shared, for what I think was TE012, the magnetic field is unidirectional, and the electric field circulates in the frustrum in opposite directions in the small and big end (halves) respectively. The wall force direction looks to me opposite in each half, and why it should always integrate to a net pressure escapes me.

I don't seriously doubt that you are correct but I for one, and I would guess others, would really appreciate your insight into why this is so.

Regards and thanks in advance,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 07:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418772#msg1418772">Quote from: RERT on 08/22/2015 07:04 PM</a>
Dr. Rodal -

Thanks very much for you post #812, which explained much pertaining to out previous discussion.

Of your logic, the only remaining thing I don't understand is why the side wall force must always be a pressure in TE modes. If I'm understanding the pictures Aero has shared, for what I think was TE012, the magnetic field is unidirectional, and the electric field circulates in the frustrum in opposite directions in the small and big end (halves) respectively. The wall force direction looks to me opposite in each half, and why it should always integrate to a net pressure escapes me.

I don't seriously doubt that you are correct but I for one, and I would guess others, would really appreciate your insight into why this is so.

Regards and thanks in advance,

R.

Dear RERT,

Please see the discussion by Greg Egan http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html, section  "Energy, pressure and forces" who (although using a very different method than mine, as Egan does NOT compute the stress tensor components, which I do carefully), explains that:

Quote
The force distributions are plotted below, for the lowest n value and lowest three k values for the TE mode(s). This time there is no Coulomb tension, so the pressure is the only contribution to the force.
(bold added for emphasis, parenthesis (s) added for clarity)

(TES.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/22/2015 07:20 PM
ref: Wolf of Wall Street and discussion of accounts.

You say there was no investment, I gather because no new shares were issued. Can you rule out sale of shares from treasury?

As regards 'Black' programs and DoD involvement: TT reported that SPR had refused his request to be a licensee because of concerns of the ?UK DoD (if I'm recall in correctly). There are a number of possibilities around who is lying to whom, so I wouldn't draw too much comfort from that. At best, were SPR a scam they would doubtless have found a way to take money from TT.

TT also reports (forgive my imperfect recall) "SPR have smart people working on the superconducting...". If that is not showing up as payroll costs (and isn't Shawyer!), it occurs that one way to fund SPR noiselessly would be to second staff to them who stay on someone else's payroll.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/22/2015 07:20 PM
Anyone know where one can find performance such as this:

http://www.maxamps.com/proddetail.php?prod=Lipo-22000-74-Pack

....or better, but without such a hefty price?

I have the voltage regulators so I can go full DC now (and ditch the galinstan slipring). I just have to get as much battery bang as I can for my buck. Any suggestions?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 07:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418767#msg1418767">Quote from: Rodal on 08/22/2015 06:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
Yes right! I get
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/22/2015 07:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 07:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418777#msg1418777">Quote from: X_RaY on 08/22/2015 07:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418767#msg1418767">Quote from: Rodal on 08/22/2015 06:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
Yes right! I get
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...
You get the same results that I do?

and way different from TheTraveller's spreadsheet?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/22/2015 07:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418725#msg1418725">Quote from: Rodal on 08/22/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418721#msg1418721">Quote from: rfmwguy on 08/22/2015 02:46 PM</a>
...Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test?  Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case)
Location is almost identical to EW on small end.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/22/2015 07:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418758#msg1418758">Quote from: SteveD on 08/22/2015 05:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)

Can you post pictures of your device and rig?
I'll do a walkaround video within 24 hrs.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 07:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418781#msg1418781">Quote from: rfmwguy on 08/22/2015 07:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418725#msg1418725">Quote from: Rodal on 08/22/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418721#msg1418721">Quote from: rfmwguy on 08/22/2015 02:46 PM</a>
...Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test?  Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case)
Location is almost identical to EW on small end.

NASA Eagleworks has the RF feed at the Big End for their reported experiment. They cannot have the RF feed at the small end because the dielectric insert (HDPE) is located at the small end. 

Please clarify whether you made a typo and you meant to write that you have it at the big end or whether you do have it at the small end, perhaps based on the proposal (not yet tested) by Paul March to have an EM Drive without a dielectric insert, with a magnetron at the small end tested in a teeter-totter instead of a the torque balance, as in this drawing:

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1058904,3Bimage.pagespeed.ic.vM_8dbeSSw.webp)

Thanks

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 07:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418780#msg1418780">Quote from: Rodal on 08/22/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418777#msg1418777">Quote from: X_RaY on 08/22/2015 07:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418767#msg1418767">Quote from: Rodal on 08/22/2015 06:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
Yes right! I get
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...
You get the same results that I do?

and way different from TheTraveller's spreadsheet?
For this dimensions Yes
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
theta=14,6942464607

EDIT: Note that i use c in vac, therefore a dielectric value inside the resonator of eps_air=1.001

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/22/2015 07:56 PM
Dr. Rodal - Thanks. The Egan page was a cold shower for emdrive optimists, but leaving that aside explains what you have been saying.

His analysis depends on E-Parallel being zero, which is not strictly correct, but it isn't much to cling to!

Regards,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 07:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418780#msg1418780">Quote from: Rodal on 08/22/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418777#msg1418777">Quote from: X_RaY on 08/22/2015 07:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418767#msg1418767">Quote from: Rodal on 08/22/2015 06:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
Yes right! I get
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...
You get the same results that I do?

and way different from TheTraveller's spreadsheet?

I trying the Travelers Spread sheet I just downloaded, it's a little confusing on his settings as to what's happening and what to select. It seems to want to bomb when I select mode TE12 from his chart. Anyone care to try it, just don't have enough time playing around with it I guess.

Shell

Added
On another note my magnetron center frequency is stable at 2.47GHz

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 08:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418789#msg1418789">Quote from: RERT on 08/22/2015 07:56 PM</a>
Dr. Rodal - Thanks. The Egan page was a cold shower for emdrive optimists, but leaving that aside explains what you have been saying.

His analysis depends on E-Parallel being zero, which is not strictly correct, but it isn't much to cling to!

Regards,

R.

Using spherical coordinates, as per Egan's drawing spherical radius r, and angles theta and phi,

(CavityShape.gif)
 which direction do you call "E-parallel" and why do you think Egan's assumption incorrect?

I don't recall Egan making any major error...

The only issue with Egan is that he considers the case for the RF feed being OFF.  Egan's conclusions are correct for the RF feed being OFF and just having standing waves

With the RF feed off all the experiments show zero force

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 08:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418790#msg1418790">Quote from: SeeShells on 08/22/2015 07:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418780#msg1418780">Quote from: Rodal on 08/22/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418777#msg1418777">Quote from: X_RaY on 08/22/2015 07:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418767#msg1418767">Quote from: Rodal on 08/22/2015 06:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418280#msg1418280">Quote from: flux_capacitor on 08/20/2015 10:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
TE012 excitation

For the new dimensions you provided I get a very good TE013 excitation at 2.47 GHz, according to TT's spreadsheet.

This is for flat ends. Do you plan flat or spherical ends?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418256#msg1418256">Quote from: SeeShells on 08/20/2015 09:59 PM</a>
External magnetron coupled to 4 loops internally at H plane 180 phase shifted […] And two additional and equal length but added lambda/4 for a 90 phase shift for a total of 180 deg on each. Quad loops ~1/5 WL 10 gauge copper loops excited in the H plane supported by the vertical tuning quartz rod.
Could you post a drawing showing the antennas shape and placement?

Shell,  my understanding from numerous posts is that you are looking at getting TE012 resonance with this design.  Please notice that you are NOT going to get TE012 resonance with your proposed dimensions.  Flux Capacitor gets TE013 resonance instead.  I don't get TE012 resonance at 2.45 GHz either, far away from it

Using:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends

I get this cone half-angle:

theta=14.69 degrees

and these resonances:

TE012 =2.033 GHz
TE013 =2.418 GHz  with a Q = 83,300

Note:

a) there is no way it can resonate at 2.45 GHz in TE012, the resonance for TE012 is 2.03 GHz which is very far away. 

b) even TE013 resonates a frequency below 2.45GHz, it resonates at 2.42 GHz. 

c) using the extension, extending the length, will make it even more difficult to resonate in TE013.  Remember than longer length lower the natural frequencies of given mode shapes

d) you have to make the EM Drive shorter

////////////////////////////////////////////

Decreasing the length to 0.163 meters results in:

bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.163(*meter*);
assuming flat ends

I get this cone half-angle:

theta = 22.50 degrees

and these resonances:

TE012 = 2.450 GHz  Q = 73,800
TE013 = 3.152 GHz  Q=  70,000

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes
Yes right! I get
TE012: 2,0338837667GHz
TE013:2,4183010112GHz
for the upper dimensions and flat end plates.
As you sad: Double check all numbers! Again and again and so on...
You get the same results that I do?

and way different from TheTraveller's spreadsheet?

I trying the Travelers Spread sheet I just downloaded, it's a little confusing on his settings as to what's happening and what to select. It seems to want to bomb when I select mode TE12 from his chart. Anyone care to try it, just don't have enough time playing around with it I guess.
Can you share the download link please. I want to get a look and play with

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 08:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418786#msg1418786">Quote from: X_RaY on 08/22/2015 07:42 PM</a>
For this dimensions Yes
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
theta=14,6942464607

My Length was different as I didn't know See-Shells would use a cylindrical neck extension.
I assumed L = 0.262 m (and a half-cone angle of 14.45°) and c in ambient air, while you use 0.2574 m and c in vac.

I indeed found for L = 0.262 m a TE013 resonance at 2.47 GHz using c in ambient air, with TT's spreadsheet.

It is my understanding that SeeShells will use the length of 0.2574 m to build the frustum: it is the vertical length between the big base and the small end while the small end is at minimal extension into the cylindrical neck. But the final length between plates once tuned will be actually longer, as the small base will be recessed into the cylindrical extension (the distance plate to plate was set to be 0.262 m)

The spreadsheet cannot handle shapes with a cylinder extension added to a conical portion. In this case the distance between plates is longer but the cone angle is kept the same.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 08:17 PM
X_Ray
Wiki page
http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 08:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418794#msg1418794">Quote from: flux_capacitor on 08/22/2015 08:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418786#msg1418786">Quote from: X_RaY on 08/22/2015 07:42 PM</a>
For this dimensions Yes
bigDiameter = 0.295(*meter*); smallDiameter = 0.160(*meter*); axialLength = 0.2574(*meter*);
assuming flat ends
theta=14,6942464607

My Length was different as I didn't know See-Shells would use a cylindrical neck extension.
I assumed L = 0.262 m (and a half-cone angle of 14.45°) and c in ambient air, while you use 0.2574 m and c in vac.

I indeed found for L = 0.262 m a TE013 resonance at 2.47 GHz using c in ambient air, with TT's spreadsheet.

It is my understanding that SeeShells will use the length of 0.2574 m to build the frustum: it is the vertical length between the big base and the small end while the small end is at minimal extension into the cylindrical neck. But the final length between plates once tuned will be actually longer, as the small base will be recessed into the cylindrical extension (the distance plate to plate was set to be 0.262 m)

The spreadsheet cannot handle shapes with a cylinder extension added to a conical portion. In this case the distance between plates is longer but the cone angle is kept the same.
For TE013 and a lenght of 262mm i get 2,3960911146GHz theta=14,4471°
That's very close.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/22/2015 08:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418784#msg1418784">Quote from: Rodal on 08/22/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418781#msg1418781">Quote from: rfmwguy on 08/22/2015 07:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418725#msg1418725">Quote from: Rodal on 08/22/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418721#msg1418721">Quote from: rfmwguy on 08/22/2015 02:46 PM</a>
...Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test?  Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case)
Location is almost identical to EW on small end.

NASA Eagleworks has the RF feed at the Big End for their reported experiment. They cannot have the RF feed at the small end because the dielectric insert (HDPE) is located at the small end. 

Please clarify whether you made a typo and you meant to write that you have it at the big end or whether you do have it at the small end, perhaps based on the proposal (not yet tested) by Paul March to have an EM Drive without a dielectric insert, with a magnetron at the small end tested in a teeter-totter instead of a the torque balance, as in this drawing:

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1058904,3Bimage.pagespeed.ic.vM_8dbeSSw.webp)

Thanks
There was a coupling loop on an EW pic behind the HDPE. It was abt 3.5 cm from edge, which is where mine is.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/22/2015 08:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 08:29 PM
Do you get the spreadsheet on the wiki? I modified the link so you can download it again, because it seems TheTraveller denied access to his Gdrive and deleted all his messages posted on NSF in the last 6 days (as well as his Reddit account) :-\

The new URL:
https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1 (https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/22/2015 08:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418697#msg1418697">Quote from: rfmwguy on 08/22/2015 01:18 PM</a>
NSF-1701 update - Last night, I finished the test stand and discovered that the beam support wire stabilized the vertical oscillation so well that I have no need for the oil bath dampener. This lowers the overall weight of the assembly and simplifies it. The laser is end-mounted, throwing about 20 feet to the target. There is significant dispersion, but small interference patterns from the panoramic mirrow reflector generates small dot patterns that I can use to calibrate. 1 gram throws it off the target. 500 mg is full target vertical travel. While this will not show resolution of 1 mg, anything over that should be readable. Approximately 20 mg will equate to 200 millinewtons of force. Anything smaller than that is not practical for any home-builder IMHO. So...the galinstan arrived and it is ready to go. But I have a weekend to enjoy first  ;)

Please check the units. If for simplification the usual 9.81 m/s² (1g) is set to 10 then 1kg force is 10N, 1g force is 10mN,  20 mg force will equate to 200 micronewtons of force.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 08:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418790#msg1418790">Quote from: SeeShells on 08/22/2015 07:56 PM</a>
I trying the Travelers Spread sheet I just downloaded, it's a little confusing on his settings as to what's happening and what to select. It seems to want to bomb when I select mode TE12 from his chart. Anyone care to try it, just don't have enough time playing around with it I guess.

Shell

Added
On another note my magnetron center frequency is stable at 2.47GHz

Shell, I will soon post some explanation as how to basically use the spreadsheet on the wiki.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 08:39 PM
That's the one with lots of duplication of the same value, isn't it? If I had the energy I'd rip it up and redesign it
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 08:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418806#msg1418806">Quote from: deltaMass on 08/22/2015 08:39 PM</a>
That's the one with lots of duplication of the same value, isn't it? If I had the energy I'd rip it up and redesign it

Do you imply you'd need a perpetual motion over-unity device to reach the energy you need for that?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/22/2015 09:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418698#msg1418698">Quote from: VAXHeadroom on 08/22/2015 01:25 PM</a>
If 1N/kW could be proven, every aerospace company on the planet would be building these.  Yes, it's that big a game-changer.   Mind you, if I understand the physics correctly, a 100% efficient unit would be 1KN/KW right?  That means currently we're only talking about a 0.1% efficiency (1N) and that would be enough to change the face of spaceflight.   Figure this thing out and the money will come at you like a firehose (my conjecture).

I fail to see what is the relation between 1kN and 1kW that would make 1kN/kW "100% efficient". In SI units N is kg*m/s² and W is kg*m²/s3, the ratio of N/W is the inverse of a velocity in m/s. Saying that 1kN/kW is anything special is saying that 1m/s is a special speed, while the meter and the second (and hence the speed 1 m/s) are not natural units in any respect.

On the other hand 3.33*10-9N/W is a special value since it is the inverse of the very special natural speed c, and it is the natural limit of propulsion efficiency for anything that is "self fed" and self powered in deep space (i.e. not relying on incoming mass or energy flow or nearby objects field) if one includes the energy equivalent of spent mass in the case of classical action-reaction (chemical rocket, ion thruster...).

100% efficiency is 3.33*10-9N/W, above that is above 100% and leads to apparent overunity (energy wise). And this is not sounding like a broken record, more like time invariance of reality.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 09:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418795#msg1418795">Quote from: SeeShells on 08/22/2015 08:17 PM</a>
X_Ray
Wiki page
http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools
I think that's not for FLAT end plates...
If i change the value for "spherical" it make no difference.
(red text)

@TT: What is a "SPR adj Factor"?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 09:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418810#msg1418810">Quote from: frobnicat on 08/22/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418698#msg1418698">Quote from: VAXHeadroom on 08/22/2015 01:25 PM</a>
If 1N/kW could be proven, every aerospace company on the planet would be building these.  Yes, it's that big a game-changer.   Mind you, if I understand the physics correctly, a 100% efficient unit would be 1KN/KW right?  That means currently we're only talking about a 0.1% efficiency (1N) and that would be enough to change the face of spaceflight.   Figure this thing out and the money will come at you like a firehose (my conjecture).

I fail to see what is the relation between 1kN and 1kW that would make 1kN/kW "100% efficient". In SI units N is kg*m/s² and W is kg*m²/s3, the ratio of N/W is the inverse of a velocity in m/s. Saying that 1kN/kW is anything special is saying that 1m/s is a special speed, while the meter and the second (and hence the speed 1 m/s) are not natural units in any respect.

On the other hand 3.33*10-9N/W is a special value since it is the inverse of the very special natural speed c, and it is the natural limit of propulsion efficiency for anything that is "self fed" and self powered in deep space (i.e. not relying on incoming mass or energy flow or nearby objects field) if one includes the energy equivalent of spent mass in the case of classical action-reaction (chemical rocket, ion thruster...).

100% efficiency is 3.33*10-9N/W, above that is above 100% and leads to apparent overunity (energy wise). And this is not sounding like a broken record, more like time invariance of reality.
Look, go easy on the guy. He doesn't have the first clue about the physics of it. He just wants to be involved. You know, emotionally.  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 09:30 PM
I updated the screenshot at http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools
and added captions to show how to use the spreadsheet.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 09:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418801#msg1418801">Quote from: flux_capacitor on 08/22/2015 08:29 PM</a>
Do you get the spreadsheet on the wiki? I modified the link so you can download it again, because it seems TheTraveller denied access to his Gdrive and deleted all his messages posted on NSF in the last 6 days (as well as his Reddit account) :-\

The new URL:
https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1 (https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1)
Bruised sensitivities? If it happened here, I surely missed it.

OH, hang on. Might this have been a tantrum occasioned by the dissection of the SPR financials?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/22/2015 09:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418721#msg1418721">Quote from: rfmwguy on 08/22/2015 02:46 PM</a>
Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...

Maybe using a scavenged mirror from an old reflex camera ? That can be quite good (and lightweight) mirror, but small, what is the size of mirror needed by your set up ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 09:36 PM
The pinhole size can make a difference too. Best to play around with it, yes.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/22/2015 09:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418814#msg1418814">Quote from: flux_capacitor on 08/22/2015 09:30 PM</a>
I updated the screenshot at http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools
and added captions to show how to use the spreadsheet.
OK, thank's

PS: yes i have to press the enter button after changing a value in libre office  :-[
it's midnight in germany, enough for today..

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 09:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418811#msg1418811">Quote from: X_RaY on 08/22/2015 09:13 PM</a>
I think that's not for FLAT end plates...
If i change the value for "spherical" it make no difference.
(red text)

@TT: What is a "SPR adj Factor"?

There's something going wrong in the calcs of your software. With what you inputted you shouldn't obtain # in various cells for "BesselJ cutoff". Can you open the spreadsheet in Microsoft Excel or online in OneDrive (https://onedrive.live.com) if you don't have MS Office? (free account) - EDIT:
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418820#msg1418820">Quote from: X_RaY on 08/22/2015 09:39 PM</a>
PS: yes i have to press the enter button after changing a value in libre office  :-[
Ok then, I was afraid of some worse incompatibility :)

"SPR adj Factor" aligns SPR resonance (as calculated by their in-house developed program) with TT's spreadsheet resonance. No need for new designs.

According to TT you can also use the Excel "goal seek" function to find the optimal frequency for any chosen frustum length.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 10:06 PM
I cut TheTraveller slack because of that heinous medical condition he is battling right now. I don't think it's fair to hold him to a deadline when that sort of crap is going on inside of him.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 10:08 PM
I agree
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/22/2015 10:08 PM
Dr. Rodal -

When  I refer to "E-Parallel=0" I  mean the generally accepted boundary condition that the electric field parallel to the surface of a conductor is zero. He uses this everywhere.

In fact, it is only an approximation, akin to electrons having zero mass. In fact, Electrons (must surely) take a small amount of time to accelerate and react to imposed fields.

However, the time is very short, and it really isn't much to cling to.

While I'm here, a pure maths nit on his paper would be that he has not shown that TE and TM are the only solutions, only that they are solutions.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 10:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418798#msg1418798">Quote from: rfmwguy on 08/22/2015 08:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418784#msg1418784">Quote from: Rodal on 08/22/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418781#msg1418781">Quote from: rfmwguy on 08/22/2015 07:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418725#msg1418725">Quote from: Rodal on 08/22/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418721#msg1418721">Quote from: rfmwguy on 08/22/2015 02:46 PM</a>
...Yes, I tried that but it attenuated more than focused...I'm still going to play around with it tho. Biggest detriment I see so far is reflective mirror injects junk into beam since its not perfect surface. Not going to invest in lab quality optics, however...
Where will be the RF feed located in your first test?  Will the magnetron be located near the big base or the small base of the truncated cone cavity? (sorry for my poor recollection if you already answered this, and thanks in advance for taking the time to answer it again in that case)
Location is almost identical to EW on small end.

NASA Eagleworks has the RF feed at the Big End for their reported experiment. They cannot have the RF feed at the small end because the dielectric insert (HDPE) is located at the small end. 

Please clarify whether you made a typo and you meant to write that you have it at the big end or whether you do have it at the small end, perhaps based on the proposal (not yet tested) by Paul March to have an EM Drive without a dielectric insert, with a magnetron at the small end tested in a teeter-totter instead of a the torque balance, as in this drawing:

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1058904,3Bimage.pagespeed.ic.vM_8dbeSSw.webp)

Thanks
There was a coupling loop on an EW pic behind the HDPE. It was abt 3.5 cm from edge, which is where mine is.
Fig 7 and 15 in NASA's report

Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum
David A. Brady*, Harold G. White†, Paul March‡, James T. Lawrence§, and Frank J. Davies**

show the RF feed to take place at the Big End.  Sorry, but I don't see how can they have an RF feed at the small end when the HDPE dielectric insert is there.  But it is possible that I am wrong and I have missed something.   I post this just to clarify things and find a common basis of agreement, and because I found out from Meep that the location of the RF feed makes a huge difference in the results, not because I want to argue.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/22/2015 10:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418828#msg1418828">Quote from: RERT on 08/22/2015 10:08 PM</a>
Dr. Rodal -

When  I refer to "E-Parallel=0" I  mean the generally accepted boundary condition that the electric field parallel to the surface of a conductor is zero. He uses this everywhere.

In fact, it is only an approximation, akin to electrons having zero mass. In fact, Electrons (must surely) take a small amount of time to accelerate and react to imposed fields.

However, the time is very short, and it really isn't much to cling to.

While I'm here, a pure maths nit on his paper would be that he has not shown that TE and TM are the only solutions, only that they are solutions.

R.

My opinion is that "E-Parallel=0" is an excellent approximation that one can show makes no practical difference for this problem.

Also, this is not Greg Egan's solution, it is a well-known solution that has been known since at least the 1930's (from Schelkunoff who at that time was at Bell Labs).  I have no problem with it within the stated assumptions (only valid for RF feed OFF, for the eigenvalue problem of standing waves).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/22/2015 10:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418658#msg1418658">Quote from: deltaMass on 08/22/2015 05:23 AM</a>
Please save us time on this. WikiP reports delta-c/c <= 10-17 from the most recent measurements. Is this the value taken by your two guys?
viXra is just about the last place to go for "information", btw.

OK, I peeked. This from arXiv critiques your sources
http://arxiv.org/abs/1404.6095

Diurnal and seasonal variations in CO2 is the likely culprit.

Well I'm certainly not interested in citing vixra trying to overthrow consensus. But I am also obliged to think differently nowadays because of this silly copper can. It is interesting reading nonetheless.

I fully ascribe to the fact that there are no preferred reference frames. At the same time, I'm seeing tantalizing clues that it may be possible to artificially create a preferred reference frame. Think back to the "laser through the resonant cavity" experiment * reported by Star-Drive and the magnetoelectric anisotropy in air experiment I linked to so many times.

The common theme there anisotropy in the speed of light in a medium while under external electromagnetic fields.

So if you have an experiment that shows the speed of light is different going forward as opposed to coming back, where is the preferred frame? Does that by definition set a preferred frame? I'm not sure. This is where all this Aether stuff comes in, as some believe the Aether is either partially or completely entrained by matter. If indeed it is found to be possible to create a preferred reference frame, is that going to ruin everyone's day?

I want to make sure people understand that when I say Aether, I'm not referring to the Luminiferous Aether. I mean the one where there is no concept of motion.

Curious to note, that within the EmDrive's tapered cavity, we have a varying group velocity from fore to aft. Same for phase velocity.** But if you flip the whole thing over, there is symmetry.

With the EmDrive in mind here, and just for S&G's here, assuming that if such a Relativistic Aether exists and that the electromagnetic component (what we call the electromagnetic vacuum) of that Aether must obey the same laws as the real electromagnetic component, did an artificial preferred frame get created in there?

Is breaking the symmetry of a simple cylindrical resonator enough to do this? I don't think so. I've been looking for a parity violation of in an empty copper can for months now and I can't find it. The closest thing that even resembles handedness would be the counter rotating E fields as seen in the TE012 Comsol plot from Eagleworks.

* All I can do is take their word that they ruled out the obvious like refractive index, heating...etc
** http://www.microwaves101.com/encyclopedias/light-phase-and-group-velocities (bottom two equations)

For me, what is important here, and pretty much my entire focus is (trusting all the experiments completed to date aren't all flawed) figuring out how momentum is conserved. We spend a lot of time here creating valuable data and analysis, but I choose to sit out most of that because I view those as optimizations.

I don't think we'll make much progress unless the physics is found first. I would honestly walk away from this whole thing if I knew that the pros from academia were on it. This EmDrive is such a hot potato apparently, that only a dirty dozen or so even really cares.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 10:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418798#msg1418798">Quote from: rfmwguy on 08/22/2015 08:21 PM</a>
There was a coupling loop on an EW pic behind the HDPE. It was abt 3.5 cm from edge, which is where mine is.

If you mean this internal picture, the loop was near the 280 mm big base:

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057032,3Bimage.pagespeed.ic.AwGtB_pjPB.jpg)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/22/2015 10:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418801#msg1418801">Quote from: flux_capacitor on 08/22/2015 08:29 PM</a>
Do you get the spreadsheet on the wiki? I modified the link so you can download it again, because it seems TheTraveller denied access to his Gdrive and deleted all his messages posted on NSF in the last 6 days (as well as his Reddit account) :-\

The new URL:
https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1 (https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1)

Yeah indications are that TT walked away. I don't know what all happened over on our sister thread, but the end result is we lost a valuable ally in the fight.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/22/2015 10:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418833#msg1418833">Quote from: Mulletron on 08/22/2015 10:27 PM</a>
Yeah indications are that TT walked away. I don't know what all happened over on our sister thread, but the end result is we lost a valuable ally in the fight.

I saw part of what seemed a hard quarrel on Reddit but not all of it and when I went back all posts were gone (when an account on Reddit is deleted, all posts of that person are deleted but also all the answers and the answers to those answers by other people). There I wrote:

Quote
[TheTraveller] apparently didn't deleted his profile on NSF, but he apparently deleted all his posts on NSF from the last 6 days :(

I know he is continuously downvoted for his public behavior, but we need to keep in mind several things with TheTraveller:

1. He is the only one who has a direct connection to Roger Shawyer.

2. He made an Excel spreadsheet publicly available to calculate frustum dimensions and resonant modes, excellent for DIYers.

3. He is the only one planning an experiment where all the electronics and batteries, besides the EmDrive, are self-contained within a rotary test rig. Everyone else is planning scale or fulcrum tests with 1) external power supplies and 2) with limited acceleration due to very short distance, which makes TT's experiment unique and extremely valuable.

4. He has some knowledge and connections for building precise solid copper frustums from high speed metal lathe spinning, including spherical end plates, while everyone else is making their flat ends copper frustum from metallic meshes or copper sheets joined with tin and welded torches.

5. As an engineer he worked before on software and hardware feedback control loop systems. Now he is currently developing such a system for his EmDrive that will maintain a center resonant frequency while his cavity detunes.

6. He is planning to make a small series production of his test rig that can be shipped to any lab for IV&V

7. He is spending $20K out of his pocket to do so. I don't argue about his own money or crowd-funding money which is perfectly fine for me (please support See-Shell (http://www.gofundme.com/yy7yz3k) also!) but the sum of money is impressive and should lead to a very qualitative build on par with Boeing's Flight Thruster designed by SPR.

8. And I'm sorry to say that, he may not have the time he needs due to his serious disease. That's why he may be overly impatient and irascible. I'm not excusing his behavior (I don't like how he talks to other people) but I keep thinking about all other points above.

So yes, his leaving is unfortunate. I hope he will return at last on NSF to present the results of his test rig.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Slyver on 08/22/2015 10:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418833#msg1418833">Quote from: Mulletron on 08/22/2015 10:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418801#msg1418801">Quote from: flux_capacitor on 08/22/2015 08:29 PM</a>
Do you get the spreadsheet on the wiki? I modified the link so you can download it again, because it seems TheTraveller denied access to his Gdrive and deleted all his messages posted on NSF in the last 6 days (as well as his Reddit account) :-\

The new URL:
https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1 (https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1)

Yeah indications are that TT walked away. I don't know what all happened over on our sister thread, but the end result is we lost a valuable ally in the fight.
That is really a shame.  It wasn't always enjoyable wading through the fanaticism, which kept strumming the chord in me "this stance is antithesis of the scientific process", but his input was often insightful, and his contributions many.

Despite whatever the truth of his beliefs may or may not be, I also recognize that there have been some great contributions to science and technology from people with unwavering beliefs, even if they turned out to be at least partially (or sometimes completely) wrong (Ptolemy e.g.). I was very much looking forward to his experiments. In the end, data is king, and more data is more...  king.  :)

Hopefully he will return. If not, I wish him well with his personal tribulations.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 11:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418820#msg1418820">Quote from: X_RaY on 08/22/2015 09:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418814#msg1418814">Quote from: flux_capacitor on 08/22/2015 09:30 PM</a>
I updated the screenshot at http://emdrive.wiki/Useful_EMDrive_Design_and_Test_Tools
and added captions to show how to use the spreadsheet.
OK, thank's

PS: yes i have to press the enter button after changing a value in libre office  :-[
it's midnight in germany, enough for today..
Got it Thanks! That makes more sense. I just went back and indeed he locked out the sheet. How childish.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/22/2015 11:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418815#msg1418815">Quote from: deltaMass on 08/22/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418801#msg1418801">Quote from: flux_capacitor on 08/22/2015 08:29 PM</a>
Do you get the spreadsheet on the wiki? I modified the link so you can download it again, because it seems TheTraveller denied access to his Gdrive and deleted all his messages posted on NSF in the last 6 days (as well as his Reddit account) :-\

The new URL:
https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1 (https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1)
Bruised sensitivities? If it happened here, I surely missed it.

OH, hang on. Might this have been a tantrum occasioned by the dissection of the SPR financials?

I hope he's ok.  Also hope it isn't indicative of a failed test.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/22/2015 11:09 PM
Too early for a failed test, I believe. It might also be that Shawyer has put the squeeze on him and taken him private.

It's a great shame if he's walked, because (with no disrespect intended to other heroic DIYers) he had the best damn experimental design I've yet seen. I hope he reconsiders. I also hope he can beat that disease.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 11:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418799#msg1418799">Quote from: aero on 08/22/2015 08:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.
Let's shrink it up areo! My mistake let's do the TE012 right this time using Dr. Rodals and X_Ray's lengths @ 163mm, keep the top circular tube @ 100mm and the same insertion depth as before. Let Harmiv calculate the resonate frequency and Q.

I'll be interested how this mode looks with this short of length.

This ok? Thanks Areo!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/22/2015 11:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418833#msg1418833">Quote from: Mulletron on 08/22/2015 10:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418801#msg1418801">Quote from: flux_capacitor on 08/22/2015 08:29 PM</a>
Do you get the spreadsheet on the wiki? I modified the link so you can download it again, because it seems TheTraveller denied access to his Gdrive and deleted all his messages posted on NSF in the last 6 days (as well as his Reddit account) :-\

The new URL:
https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1 (https://www.dropbox.com/s/u6v90c5yb050u52/EMDriveCalc20150809a.xlsx?dl=1)

Yeah indications are that TT walked away. I don't know what all happened over on our sister thread, but the end result is we lost a valuable ally in the fight.
As head strong as he was, I'll still say yes. There is no bad data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/22/2015 11:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418735#msg1418735">Quote from: Ricvil on 08/22/2015 03:40 PM</a>
http://ir.hfcas.ac.cn/bitstream/334002/12022/1/
Mode%20converters%20for%20generating%20the
%20HE%2011%20%28gaussian%20like%29%20mode
%20from%20TE%2001%20in%20a%20circular%20waveguide.pdf

In the above article, the mode coupling theory shows how  a bended circular waveguide transforms a TE01 mode into a TM11 mode.
Of course, always will be spurious modes in the process.
My questions are about :
1- By temporal reverse symmetry , the same bended pipe can transform both TE into TM and TM into TE modes?
2-By Parity/mirror symmetry, if one cuts the same converter at it's half lenght and close one of the ends with the same metal of the waveguide, then if one inject a TE mode at the other open end, one gets a TM reflected mode?

Another question.
The TE01 and TM11 modes has different atenuation at same frequency right?
Let's suppose one has two simultaneous  incident power flux of same intensity, one TE01  from left to right, and other TM11 from right to left, on a straight cilindrical waveguide, then if TM11 has more attenuation compared with TE01, then there are more photons absorved by waveguide from right to left, and more linear momentum transfered of electromagnectic field to the waveguide walls from right to left, and because of that, the waveguide will be pushed from right to left ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/22/2015 11:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418831#msg1418831">Quote from: Mulletron on 08/22/2015 10:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418658#msg1418658">Quote from: deltaMass on 08/22/2015 05:23 AM</a>
Please save us time on this. WikiP reports delta-c/c <= 10-17 from the most recent measurements. Is this the value taken by your two guys?
viXra is just about the last place to go for "information", btw.

OK, I peeked. This from arXiv critiques your sources
http://arxiv.org/abs/1404.6095

Diurnal and seasonal variations in CO2 is the likely culprit.

Well I'm certainly not interested in citing vixra trying to overthrow consensus. But I am also obliged to think differently nowadays because of this silly copper can. It is interesting reading nonetheless.

I fully ascribe to the fact that there are no preferred reference frames. At the same time, I'm seeing tantalizing clues that it may be possible to artificially create a preferred reference frame. Think back to the "laser through the resonant cavity" experiment * reported by Star-Drive and the magnetoelectric anisotropy in air experiment I linked to so many times.

The common theme there anisotropy in the speed of light in a medium while under external electromagnetic fields.

So if you have an experiment that shows the speed of light is different going forward as opposed to coming back, where is the preferred frame? Does that by definition set a preferred frame? I'm not sure. This is where all this Aether stuff comes in, as some believe the Aether is either partially or completely entrained by matter. If indeed it is found to be possible to create a preferred reference frame, is that going to ruin everyone's day?

I want to make sure people understand that when I say Aether, I'm not referring to the Luminiferous Aether. I mean the one where there is no concept of motion.

Curious to note, that within the EmDrive's tapered cavity, we have a varying group velocity from fore to aft. Same for phase velocity.** But if you flip the whole thing over, there is symmetry.

With the EmDrive in mind here, and just for S&G's here, assuming that if such a Relativistic Aether exists and that the electromagnetic component (what we call the electromagnetic vacuum) of that Aether must obey the same laws as the real electromagnetic component, did an artificial preferred frame get created in there?

Is breaking the symmetry of a simple cylindrical resonator enough to do this? I don't think so. I've been looking for a parity violation of in an empty copper can for months now and I can't find it. The closest thing that even resembles handedness would be the counter rotating E fields as seen in the TE012 Comsol plot from Eagleworks.

* All I can do is take their word that they ruled out the obvious like refractive index, heating...etc
** http://www.microwaves101.com/encyclopedias/light-phase-and-group-velocities (bottom two equations)

For me, what is important here, and pretty much my entire focus is (trusting all the experiments completed to date aren't all flawed) figuring out how momentum is conserved. We spend a lot of time here creating valuable data and analysis, but I choose to sit out most of that because I view those as optimizations.

I don't think we'll make much progress unless the physics is found first. I would honestly walk away from this whole thing if I knew that the pros from academia were on it. This EmDrive is such a hot potato apparently, that only a dirty dozen or so even really cares.

Great post! What you are describing is not a preferred reference frame, but rather a gravitational field, as described in the Polarizable Vacuum Model of GR. The radial metric component of the Schwarzschild metric, and gravitational red-shift are evidence that "the (coordinate) speed of light is different going forward as opposed to coming back,..".

What I've boiled down in my crucible is the question, Is the phase velocity inside the tapered cavity actually  slower than light in vacuum? If so, then this will explain our momentum greater than a photon rocket. I don't have a definitive answer for this (yet).

Here is something a friend sent me. Seems pertinent, but it is in regards to a test particle riding an EM impulse.

https://www.youtube.com/watch?v=6TcIGUJuFE0

In it, he shows that the particle can absorb more momentum than it normally would, i.e., the momentum has increased due to gravity.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/23/2015 12:04 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418843#msg1418843">Quote from: SeeShells on 08/22/2015 11:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418799#msg1418799">Quote from: aero on 08/22/2015 08:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.
Let's shrink it up areo! My mistake let's do the TE012 right this time using Dr. Rodals and X_Ray's lengths @ 163mm, keep the top circular tube @ 100mm and the same insertion depth as before. Let Harmiv calculate the resonate frequency and Q.

I'll be interested how this mode looks with this short of length.

This ok? Thanks Areo!

Shell

Like this? It looks lop-sided to me but I can't guess why. Can you?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 08/23/2015 12:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418698#msg1418698">Quote from: VAXHeadroom on 08/22/2015 01:25 PM</a>

If 1N/kW could be proven, every aerospace company on the planet would be building these.  Yes, it's that big a game-changer.   Mind you, if I understand the physics correctly, a 100% efficient unit would be 1KN/KW right?  That means currently we're only talking about a 0.1% efficiency (1N) and that would be enough to change the face of spaceflight.   Figure this thing out and the money will come at you like a firehose (my conjecture).

Only when they see someone has bought one.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 12:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418852#msg1418852">Quote from: aero on 08/23/2015 12:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418843#msg1418843">Quote from: SeeShells on 08/22/2015 11:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418799#msg1418799">Quote from: aero on 08/22/2015 08:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.
Let's shrink it up areo! My mistake let's do the TE012 right this time using Dr. Rodals and X_Ray's lengths @ 163mm, keep the top circular tube @ 100mm and the same insertion depth as before. Let Harmiv calculate the resonate frequency and Q.

I'll be interested how this mode looks with this short of length.

This ok? Thanks Areo!

Shell

Like this? It looks lop-sided to me but I can't guess why. Can you?
Yes drop the bottom and top down to your sidewall line and that will truly come close to what I should end up with.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 12:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418852#msg1418852">Quote from: aero on 08/23/2015 12:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418843#msg1418843">Quote from: SeeShells on 08/22/2015 11:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418799#msg1418799">Quote from: aero on 08/22/2015 08:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.
Let's shrink it up areo! My mistake let's do the TE012 right this time using Dr. Rodals and X_Ray's lengths @ 163mm, keep the top circular tube @ 100mm and the same insertion depth as before. Let Harmiv calculate the resonate frequency and Q.

I'll be interested how this mode looks with this short of length.

This ok? Thanks Areo!

Shell

Like this? It looks lop-sided to me but I can't guess why. Can you?

The antenna should be closer to the big base.  How are you coming up with that distance?

I have not written a program to plot the contours for flat faces, but here is what the electric azimuthal field contour plot looks like for spherical ends, so that you have a rough idea of where to place the antenna

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 12:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418859#msg1418859">Quote from: Rodal on 08/23/2015 12:26 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418852#msg1418852">Quote from: aero on 08/23/2015 12:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418843#msg1418843">Quote from: SeeShells on 08/22/2015 11:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418799#msg1418799">Quote from: aero on 08/22/2015 08:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.
Let's shrink it up areo! My mistake let's do the TE012 right this time using Dr. Rodals and X_Ray's lengths @ 163mm, keep the top circular tube @ 100mm and the same insertion depth as before. Let Harmiv calculate the resonate frequency and Q.

I'll be interested how this mode looks with this short of length.

This ok? Thanks Areo!

Shell

Like this? It looks lop-sided to me but I can't guess why. Can you?

The antenna should be closer to the big base.  How are you coming up with that distance?
It looks like the same position as in the last run for Yang. This is really squeezed down with the the base plate size almost the same as the distance between the plates.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 12:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418860#msg1418860">Quote from: SeeShells on 08/23/2015 12:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418859#msg1418859">Quote from: Rodal on 08/23/2015 12:26 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418852#msg1418852">Quote from: aero on 08/23/2015 12:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418843#msg1418843">Quote from: SeeShells on 08/22/2015 11:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418799#msg1418799">Quote from: aero on 08/22/2015 08:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418779#msg1418779">Quote from: SteveD on 08/22/2015 07:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418770#msg1418770">Quote from: aero on 08/22/2015 07:04 PM</a>
Meep does concur.

How does that stack up with the known output of the magnetron?  Is there a good reason to test in TE012 and not TE013?

I didn't get the bandwidth reduced to realistic values so the noisy source I used had over 10 times the realistic bandwdith. Resonated at about 2.426 GHz, I can't verify the mode. So meep didn't really give us much information in this case.
Let's shrink it up areo! My mistake let's do the TE012 right this time using Dr. Rodals and X_Ray's lengths @ 163mm, keep the top circular tube @ 100mm and the same insertion depth as before. Let Harmiv calculate the resonate frequency and Q.

I'll be interested how this mode looks with this short of length.

This ok? Thanks Areo!

Shell

Like this? It looks lop-sided to me but I can't guess why. Can you?

The antenna should be closer to the big base.  How are you coming up with that distance?
It looks like the same position as in the last run for Yang. This is really squeezed down with the the base plate size almost the same as the distance between the plates.

I have not written a program to plot the contours for flat faces, but here is what the electric azimuthal field contour plot looks like for spherical ends, so that you have a rough idea of where to place the antenna

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/23/2015 12:46 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418841#msg1418841">Quote from: deltaMass on 08/22/2015 11:09 PM</a>
Too early for a failed test, I believe. It might also be that Shawyer has put the squeeze on him and taken him private.

It's a great shame if he's walked, because (with no disrespect intended to other heroic DIYers) he had the best damn experimental design I've yet seen. I hope he reconsiders. I also hope he can beat that disease.

Could have been Shawyer and gotten a STFU from his government.  The irony is, I'm not sure about the theory, but I think he is basically right about the implementation.  Trying to tune the device to the input frequency is just too hard with a noisy RF source and a cavity with dimensions that change as it heats.  What we really need is to throw some computing power at it and tune the frequency to maintain Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/23/2015 01:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418863#msg1418863">Quote from: SteveD on 08/23/2015 12:46 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418841#msg1418841">Quote from: deltaMass on 08/22/2015 11:09 PM</a>
Too early for a failed test, I believe. It might also be that Shawyer has put the squeeze on him and taken him private.

It's a great shame if he's walked, because (with no disrespect intended to other heroic DIYers) he had the best damn experimental design I've yet seen. I hope he reconsiders. I also hope he can beat that disease.

Could have been Shawyer and gotten a STFU from his government.  The irony is, I'm not sure about the theory, but I think he is basically right about the implementation.  Trying to tune the device to the input frequency is just too hard with a noisy RF source and a cavity with dimensions that change as it heats.  What we really need is to throw some computing power at it and tune the frequency to maintain Q.

There for a while, I was wondering if Finkle was Einhorn, mostly because of TT's unwavering certainty that EmDrive was a sure thing (without anything to prove it yet) and his close connections with Shawyer. I asked and he said no.

This will be an interesting week for "As the Frustum Turns".

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 01:18 AM
(goingdark.jpg)

Ha!
:)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/23/2015 01:21 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418866#msg1418866">Quote from: Mulletron on 08/23/2015 01:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418863#msg1418863">Quote from: SteveD on 08/23/2015 12:46 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418841#msg1418841">Quote from: deltaMass on 08/22/2015 11:09 PM</a>
Too early for a failed test, I believe. It might also be that Shawyer has put the squeeze on him and taken him private.

It's a great shame if he's walked, because (with no disrespect intended to other heroic DIYers) he had the best damn experimental design I've yet seen. I hope he reconsiders. I also hope he can beat that disease.

Could have been Shawyer and gotten a STFU from his government.  The irony is, I'm not sure about the theory, but I think he is basically right about the implementation.  Trying to tune the device to the input frequency is just too hard with a noisy RF source and a cavity with dimensions that change as it heats.  What we really need is to throw some computing power at it and tune the frequency to maintain Q.

There for a while, I was wondering if Finkle was Einhorn, mostly because of TT's unwavering certainty that EmDrive was a sure thing (without anything to prove it yet) and his close connections with Shawyer. I asked and he said no.

This will be an interesting week for "As the Frustum Turns".
because "as the frustrum twitches a little bit" doesn't have the same cache. :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/23/2015 01:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418701#msg1418701">Quote from: VAXHeadroom on 08/22/2015 01:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417397#msg1417397">Quote from: Prunesquallor on 08/19/2015 01:03 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1417237#msg1417237">Quote from: deltaMass on 08/18/2015 04:04 PM</a>
It is way, way too early to start jumping to conclusions. Anyone who does is not being fair. Until open and replicated experimental data is available, it's all noise as far as I'm concerned. As matters stand, there is nothing that is open and replicated.

The ironclad test is a space test. This cannot readily be fooled with artifacts. What's required  for that is twin units in reasonably close proximity, one powered and one not, and in all other respects identical.

I know I'm a broken record, but IMHO there are many more uncontrollable factors in low earth orbit than in the lab, considering the minscule power available for the thruster on a cubesat.

In a 6u cubesat, we can get up to about 400W from the solar arrays and store enough to do a few KW of output for short periods (several minutes).  That avionics bus design is on my computer now (I do avionics for a living).

If I was forced to do a cubesats flight test, I think I would do the 5u linear configuration, put the biggest battery I could in it, put the thruster on the end cube and see it I could get it rotating like a baton (as long as there is a way to detect the rotation - are there micro-RLGs?). This would be analogous to the rotating table tests some of the DiYers are contemplating. It would also avoid the issues of trying to isolate small velocity changes from drag and orbital mechanics effects.

There would still be challenges of stabilizing the spacecraft about the minor axis and what such a potential rotation would mean for power generation and communications.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/23/2015 01:51 AM
How do you get angular momentum out of a system which starts out with none? Surely the entire stick will just translate? (replacing EmDrive with a rocket so it's something we are sure works well). Unless the centre of rotation has an oar bolted to it that dips into the Aetheric Aether (that was sarcasm) it won't spin.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/23/2015 01:52 AM
@SeeShell
How's this?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: snoozdoc on 08/23/2015 02:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418875#msg1418875">Quote from: Prunesquallor on 08/23/2015 01:38 AM</a>
If I was forced to do a cubesats flight test, I think I would do the 5u linear configuration, put the biggest battery I could in it, put the thruster on the end cube and see it I could get it rotating like a baton (as long as there is a way to detect the rotation - are there micro-RLGs?). This would be analogous to the rotating table tests some of the DiYers are contemplating. It would also avoid the issues of trying to isolate small velocity changes from drag and orbital mechanics effects.

There would still be challenges of stabilizing the spacecraft about the minor axis and what such a potential rotation would mean for power generation and communications.

3-Axis Gyro/Accelerometer('s) are very available in a single chip package ... and cheap  :)
https://www.sparkfun.com/products/10937

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/23/2015 02:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418876#msg1418876">Quote from: deltaMass on 08/23/2015 01:51 AM</a>
How do you get angular momentum out of a system which starts out with none? Surely the entire stick will just translate? (replacing EmDrive with a rocket so it's something we are sure works well). Unless the centre of rotation has an oar bolted to it that dips into the Aetheric Aether (that was sarcasm) it won't spin.

Of course it will spin, after a fashion. No different than a stabilized satellite with one RCS stuck "ON." It will have a combined linear force that you are referring to, and a torque about the cg. I think it will spiral.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/23/2015 02:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418876#msg1418876">Quote from: deltaMass on 08/23/2015 01:51 AM</a>
How do you get angular momentum out of a system which starts out with none? Surely the entire stick will just translate? (replacing EmDrive with a rocket so it's something we are sure works well). Unless the centre of rotation has an oar bolted to it that dips into the Aetheric Aether (that was sarcasm) it won't spin.

For your rocket analogy, that is exactly how attitude control thrusters rotate spacecraft - creating a force times moment arm. This causes an angular acceleration as long as the force is applied, which causes a change in spacecraft angular momentum. "System" angular momentum is conserved when one includes the momentum vector if the ejected propellant stream.

How it is conserved with something like an EM Drive is, of course the 60 trillion dollar question.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/23/2015 02:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418876#msg1418876">Quote from: deltaMass on 08/23/2015 01:51 AM</a>
How do you get angular momentum out of a system which starts out with none? Surely the entire stick will just translate? (replacing EmDrive with a rocket so it's something we are sure works well). Unless the centre of rotation has an oar bolted to it that dips into the Aetheric Aether (that was sarcasm) it won't spin.

Put it in a closed universe. Then all linear momentum is really just angular momentum, as all motion is really movement about an arc.

Visual aide:
https://www.youtube.com/watch?v=IFdfrtzo4SY

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/23/2015 02:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418878#msg1418878">Quote from: snoozdoc on 08/23/2015 02:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418875#msg1418875">Quote from: Prunesquallor on 08/23/2015 01:38 AM</a>
If I was forced to do a cubesats flight test, I think I would do the 5u linear configuration, put the biggest battery I could in it, put the thruster on the end cube and see it I could get it rotating like a baton (as long as there is a way to detect the rotation - are there micro-RLGs?). This would be analogous to the rotating table tests some of the DiYers are contemplating. It would also avoid the issues of trying to isolate small velocity changes from drag and orbital mechanics effects.

There would still be challenges of stabilizing the spacecraft about the minor axis and what such a potential rotation would mean for power generation and communications.

3-Axis Gyro/Accelerometer('s) are very available in a single chip package ... and cheap  :)
https://www.sparkfun.com/products/10937

 :)I guess I should have known that since my PHONE has them :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 02:19 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418877#msg1418877">Quote from: aero on 08/23/2015 01:52 AM</a>
@SeeShell
How's this?
Where are you placing the dipoles, directly into the center of the modes?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/23/2015 02:40 AM
Oops. Yes, rockets can "pinwheel" even when the "pin" isn't stuck into anything.

So maybe orientation isn't a big deal for a space-based test after all. All that's needed is a record of the 3D accelerations.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 02:53 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418887#msg1418887">Quote from: deltaMass on 08/23/2015 02:40 AM</a>
Oops. Yes, rockets can "pinwheel" even when the "pin" isn't stuck into anything.

So maybe orientation isn't a big deal for a space-based test after all. All that's needed is a record of the 3D accelerations.
Couldn't you stabilize the little sat with gyroscopes and push against the stabilized sat with the mini drive??

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/23/2015 03:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418886#msg1418886">Quote from: SeeShells on 08/23/2015 02:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418877#msg1418877">Quote from: aero on 08/23/2015 01:52 AM</a>
@SeeShell
How's this?
Where are you placing the dipoles, directly into the center of the modes?

Antenna placement is a parameter, chasing Q. Just like small end plate placement is a parameter chasing 2.47 GHz.
Right now it resonates poorly and is not on frequency. But it is getting closer, I just need to be careful that I don't loose what I have by going to far to fast.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/23/2015 04:13 AM
Dr. Rodal,
What were the dimensions of your spherical end model (of SeeShell's cavity) that resonates at 2.47 GHz? In particular, what were the r1 and r2 values? I've attached the image you posted, this is the one I'm asking about.
aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/23/2015 04:37 AM
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/23/2015 05:39 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418813#msg1418813">Quote from: deltaMass on 08/22/2015 09:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418810#msg1418810">Quote from: frobnicat on 08/22/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418698#msg1418698">Quote from: VAXHeadroom on 08/22/2015 01:25 PM</a>
If 1N/kW could be proven, every aerospace company on the planet would be building these.  Yes, it's that big a game-changer.   Mind you, if I understand the physics correctly, a 100% efficient unit would be 1KN/KW right?  That means currently we're only talking about a 0.1% efficiency (1N) and that would be enough to change the face of spaceflight.   Figure this thing out and the money will come at you like a firehose (my conjecture).

I fail to see what is the relation between 1kN and 1kW that would make 1kN/kW "100% efficient". In SI units N is kg*m/s² and W is kg*m²/s3, the ratio of N/W is the inverse of a velocity in m/s. Saying that 1kN/kW is anything special is saying that 1m/s is a special speed, while the meter and the second (and hence the speed 1 m/s) are not natural units in any respect.

On the other hand 3.33*10-9N/W is a special value since it is the inverse of the very special natural speed c, and it is the natural limit of propulsion efficiency for anything that is "self fed" and self powered in deep space (i.e. not relying on incoming mass or energy flow or nearby objects field) if one includes the energy equivalent of spent mass in the case of classical action-reaction (chemical rocket, ion thruster...).

100% efficiency is 3.33*10-9N/W, above that is above 100% and leads to apparent overunity (energy wise). And this is not sounding like a broken record, more like time invariance of reality.
Look, go easy on the guy. He doesn't have the first clue about the physics of it. He just wants to be involved. You know, emotionally.  8)

Honestly, that's pretty insulting.
I probably have 2 or 3 clues, but certainly not the full deck, but I also know that which is why I stated it the way I did.  Give that, what would be expected to be 100% efficiency?  Certainly not 3.33*10-6N/KW?  We've already seen results reported that are about 6 orders of magnitude higher.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/23/2015 05:44 AM
Before preparing the test in space of an EMDrive device it could be usefull to test it during the Zero-Gravity Parabolic Flights of a specialized plane. Such parabolic flight last up to 30 seconds which seems enough to detect a posssible move of the test specimen due to EMThrust.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/23/2015 05:53 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418909#msg1418909">Quote from: Mezzenile on 08/23/2015 05:44 AM</a>
Before preparing the test in space of an EMDrive device it could be usefull to test it during the Zero-Gravity Parabolic Flights of a specialized plane. Such parabolic flight last up to 30 seconds which seems enough to detect a posssible move of the test specimen due to EMThrust.

No way is a parabolic airplane flight loop long enough to do this test and see anything with a thrust less than about 1N.
Credentials to say this: I've done 160 parabolas testing a free-flying device...(last summer).

Edit: I'll modify that - you'd need about 0.1m/s2 acceleration to detect the change in the short zero-g time, so it would depend on the mass of the test device, but I'd think it would be difficult to get under several kg.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zero123 on 08/23/2015 06:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418908#msg1418908">Quote from: VAXHeadroom on 08/23/2015 05:39 AM</a>
Honestly, that's pretty insulting.
I probably have 2 or 3 clues, but certainly not the full deck, but I also know that which is why I stated it the way I did.  Give that, what would be expected to be 100% efficiency?  Certainly not 3.33*10-6N/KW?  We've already seen results reported that are about 6 orders of magnitude higher.

Well, naturally, that depends on what exactly you mean by "efficiency". If you mean energy, then 3.336*10-9N/W is indeed the right one, as anything above that means that there is an speed less than c at which it starts gaining more kinetic energy than the EM energy being put in. Yes, the reported results are orders of magnitude higher, which is why so much has been written about conservation of energy (or lack thereof) of the EMdrives.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/23/2015 06:49 AM
Or, to put it another way, anything better than 1/c N/W is more than 100% efficient, in the sense of power out divided by power in.

Sorry I was harsh, but it didn't seem to be appreciated that N/W has units of seconds per metre, or inverse velocity. Apologies for that.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Slyver on 08/23/2015 06:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418912#msg1418912">Quote from: zero123 on 08/23/2015 06:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418908#msg1418908">Quote from: VAXHeadroom on 08/23/2015 05:39 AM</a>
Honestly, that's pretty insulting.
I probably have 2 or 3 clues, but certainly not the full deck, but I also know that which is why I stated it the way I did.  Give that, what would be expected to be 100% efficiency?  Certainly not 3.33*10-6N/KW?  We've already seen results reported that are about 6 orders of magnitude higher.

Well, naturally, that depends on what exactly you mean by "efficiency". If you mean energy, then 3.336*10-9N/W is indeed the right one, as anything above that means that there is an speed less than c at which it starts gaining more kinetic energy than the EM energy being put in. Yes, the reported results are orders of magnitude higher, which is why so much has been written about conservation of energy (or lack thereof) of the EMdrives.

There is no way to discuss efficiency without having at least a viable model (consistent with thermodynamics) of the mode of operation of the device.  For photon ejection, 100% efficiency is 3.336*10-9N/W. What this means is, if you put a photon rocket on a rotating device, and turn the resulting angular momentum into electrical energy with 100% efficiency, you can never get more energy out than you put in to create the photons. The best you can do is get the same energy out that you put in.

If this device can in fact produce more energy than is put in, as the testing so far suggests, then there will be some very interesting physics that comes from this.  We have many devices from which we can produce more energy than we put in.  In fact, perhaps ALL of our energy producing devices are of this nature. However, we understand that we are in fact just using stored energy, even if we didn't actively do the storing. In the end, with all of our devices, entropy is perfectly content.

One easy example of this concept is nuclear fission energy.  We get more energy out than we put in to run a nuclear fission plant, plus the energy to extract and refine the little magic rocks we use as fuel. We (and entropy) have no problem with this because we understand (or have a good idea) that the energy stored in our magic rocks was put there from exploding stars, which used even more energy to put that energy into the rocks in the first place.

If we had discovered a way to build a nuclear plant prior to our model of quantum mechanics it would seem very much like a perpetual motion device of the first kind, but in fact it would simply be that we didn't have a good model to explain our magical machine within the scope of thermodynamics.

If we can extract energy by shooting photons into a malformed copper can, I have no problem with that.  I predict that if that is the case, we will eventually find that we are coupling with some field we were previously unaware of (or more likely unaware we could couple with it in that way) and extracting energy from it. This energy extraction will almost certainly prove to contribute to the heat death of the universe and entropy will almost certainly be very happy with us in the end.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/23/2015 07:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418911#msg1418911">Quote from: VAXHeadroom on 08/23/2015 05:53 AM</a>
No way is a parabolic airplane flight loop long enough to do this test and see anything with a thrust less than about 1N.
Credentials to say this: I've done 160 parabolas testing a free-flying device...(last summer).

Edit: I'll modify that - you'd need about 0.1m/s2 acceleration to detect the change in the short zero-g time, so it would depend on the mass of the test device, but I'd think it would be difficult to get under several kg.

If I consider a test device weighting 100 Kg (including cavity, DC Li-Ion battery, RF harness, source and power amplifier (TWT + EPC), hold-on and release mechanism..) with a thrust of 0.1 N, this would lead to an acceleration gamma of 0.001 m/s² and so to a total displacement of 0.2 m for a test duration t of 20 seconds (1/2 gamma t²). Dont'you think that this displacement could be properly observed if we use a small vaccum test chamber with observation capability surrounding at 30 cm distance the test device ?

Of course we should have calibration parabolic flights without thrust to  evaluate the 0-thrust displacement.

There is also the possibility to use a vaccuum drop tower which offers weightless or microgravity environment for a duration of 5.18 seconds (NASA data : http://facilities.grc.nasa.gov/zerog/ (http://facilities.grc.nasa.gov/zerog/)). The accurate measure of the free fall trajectory versus time should provide the thrust characteristics versus time.

I hire you for the flight test operation as you seem well experimented in this matter  ;) !! (nausea-free prooved   :D ?)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/23/2015 08:31 AM
Has The Traveller gone AWOL?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/23/2015 09:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418886#msg1418886">Quote from: SeeShells on 08/23/2015 02:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418877#msg1418877">Quote from: aero on 08/23/2015 01:52 AM</a>
@SeeShell
How's this?
Where are you placing the dipoles, directly into the center of the modes?

@aero and SeeShells, what about these dimensions:

Db = 0.295 m
Ds = 0.160 m
L = 0.174 m

flat ends
TE012
2.47 GHz

free-space wavelength λ0 = 0.12134 m
big base wavelength λb = 0.24186 m (cutoff) 0.140 m
The dipole antenna should be placed at a distance from big end equal to 1/4 wavelength, but which λ:
λ0/4 = 30 mm
λb/4 = 35 mm

EDIT: If we choose to use a loop antenna instead of a dipole antenna, its diameter should be equal to the wavelength, but which wavelength: λ0 or λb? And should its length (diameter) be a bit below or above the chosen wavelength?

EDIT2: In the following proposal with θ = 23° and cylindrical extension = 120 mm, you could tune the small end to achieve TE012 resonance at L ≈ 174 mm, but also TE013 at L ≈ 262 mm, with interesting things to measure between the two Q factors and the plate most closely to the vertex of the cone.

BTW as already explained by TheTraveller, Shawyer may have gone from TE012 to TE013 to accommodate a bigger length and bigger volume and enhance the Q. TE012 frustums have a shallow height.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/23/2015 09:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418696#msg1418696">Quote from: X_RaY on 08/22/2015 01:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418691#msg1418691">Quote from: SeeShells on 08/22/2015 12:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675">Quote from: X_RaY on 08/22/2015 09:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>


So If I understand you right, the join of the conic section and the tuning tube is 0.2244 meters up from the large end plate  which is at the big end of the conic section. The small end plate is then 0.0376m up from that join. Or do I have it backwards? This is what I understand now.

But what is the size of diameter of the tuning tube and the tuning plate (small base plate)? They can't be the same size so their must be a gap.

Small plate 160 mm, .032", O2 Free copper walls, Silver ~.30 um on endplates.
 
This should work just fine.

Thanks.

Shell

Check back later, have friends over.

But I thought you were going to use silver plated ceramic for the end plates? I liked that idea much better than copper end plates because of my hypothesis that thrust may be generated by tunnelling evanescent waves. A thin silver plate on ceramic would have a lot lower barrier height than copper end plates, although 30 um might be more than I'd like to see.

One thing that bugs me about my idea is that the math seems to be readily available to check for momentum from tunnelling evanescent waves, but I don't have the knowledge to apply it.

But back to the C-E drive, the small end plate cannot be the same diameter as the inner diameter of the tuning tube. You may try for the same size but it won't move if it is wedged in tightly and you want it to move. What is your expected tolerance on the two diameters? Millimetres? Hundreds of micrometers? Tens of micrometers? Evanescent waves will escape through this gap and we want to see them.

I'm looking at about a .0125mm gap. I've ordered 2 plates. The second one I'll modify for evanescent wave actions with a set pattern in the silver for just them and set a conductive seal between the plate and sidewalls. I just would like to see what meep does in the modes with the antennas you selected and not too worried about them this run.

Is that ok ?

Shell

Thoughts to the gap...

Shell, is your favorite target mode still TE012? If yes the field strength(E) for this mode tend to zero near the "edge" of frustum and endplate. It is zero in the corner. There will be also no current flow between the frustum and the plate.
So if the gap is small its not "visible" from the viewpoint of this mode.

For some other mode shapes the gap can work as a slot antenna, it can radiate, not in the sense of evanescent waves.. The most interesting point is the length of the slot and thats the circumference in your case(not only the width of the gap is important).

It's easier to model in meep if it's treated as connected or a small gap which aero likes, in real life I'm going around the circumference of the plate with a beryllium copper gasket that will electrically connect to the frustum and seal the endcap but allow it to slide freely.

Shell
Good plan. For all the modes which produce currents thru the gap, a good galvanic contact is necessary. While moving the plate the S-Parameter signal will look a little noisy that depends on the contact between the frustum and the plate(will be stable again after movement). The resonant frequency could be a little bit lower than calculated for a given length (MHz range, caused by longer current paths) if the metal seal is at the outer side.
For TE01p that is not the case, no noise while moving the plate.
Again its a good plan. No better idea at the moment :)
I got a better(?) idea now: You can use as RF sealing a choke.

http://www.radartutorial.eu/03.linetheory/tl13.en.html
http://www.microwaves101.com/encyclopedias/quarter-wave-tricks

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CW on 08/23/2015 09:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 01:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418939#msg1418939">Quote from: X_RaY on 08/23/2015 09:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418696#msg1418696">Quote from: X_RaY on 08/22/2015 01:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418691#msg1418691">Quote from: SeeShells on 08/22/2015 12:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675">Quote from: X_RaY on 08/22/2015 09:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418653#msg1418653">Quote from: SeeShells on 08/22/2015 04:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418648#msg1418648">Quote from: aero on 08/22/2015 04:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418640#msg1418640">Quote from: SeeShells on 08/22/2015 03:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418636#msg1418636">Quote from: aero on 08/22/2015 02:24 AM</a>
Again its a good plan. No better idea at the moment :)
I got a better(?) idea now: You can use as RF sealing a choke.

http://www.radartutorial.eu/03.linetheory/tl13.en.html
http://www.microwaves101.com/encyclopedias/quarter-wave-tricks

I haven't even downed my first cup of coffee and I was wishing I could get a "Krell brain boost". (ref: Forbidden Planet) ;) Nice thought this morning! I like it.

I was reviewing this morning in how to "semi-control" the mode generation or at least limit in some fashion all the crosstalk between modes and was starting with this idea to do after I have some solid data. Instead of placing the antenna directly within the mode,in the frustum (makes it tough to adjust each externally). I can couple it like the attached picture and do it for the bottom mode and the top mode 90 degrees shifted (of course exciting a TE012)

I could tune each separately using a VNA at low power, turn on the top or the bottom or both for tests. 

More coffee and draw what I'm thinking.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 02:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418937#msg1418937">Quote from: flux_capacitor on 08/23/2015 09:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418886#msg1418886">Quote from: SeeShells on 08/23/2015 02:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418877#msg1418877">Quote from: aero on 08/23/2015 01:52 AM</a>
@SeeShell
How's this?
Where are you placing the dipoles, directly into the center of the modes?

@aero and SeeShells, what about these dimensions:

Db = 0.295 m
Ds = 0.160 m
L = 0.174 m

flat ends
TE012
2.47 GHz

free-space wavelength λ0 = 0.12134 m
big base wavelength λb = 0.24186 m (cutoff) 0.140 m
The dipole antenna should be placed at a distance from big end equal to 1/4 wavelength, but which λ:
λ0/4 = 30 mm
λb/4 = 35 mm

EDIT: If we choose to use a loop antenna instead of a dipole antenna, its diameter should be equal to the wavelength, but which wavelength: λ0 or λb? And should its length (diameter) be a bit below or above the chosen wavelength?

EDIT2: In the following proposal with θ = 23° and cylindrical extension = 120 mm, you could tune the small end to achieve TE012 resonance at L ≈ 174 mm, but also TE013 at L ≈ 262 mm, with interesting things to measure between the two Q factors and the plate most closely to the vertex of the cone.

BTW as already explained by TheTraveller, Shawyer may have gone from TE012 to TE013 to accommodate a bigger length and bigger volume and enhance the Q. TE012 frustums have a shallow height.
Very nice, you are dang good.. and fast! I was told that the loop should be just a little less than the chosen wavelength if we choose a loop. meep has a hard time modeling a loop and getting it to work right. aero needs to make sure he gets his phases correct for the two dipoles and not in phase.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 02:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418895#msg1418895">Quote from: aero on 08/23/2015 04:13 AM</a>
Dr. Rodal,
What were the dimensions of your spherical end model (of SeeShell's cavity) that resonates at 2.47 GHz? In particular, what were the r1 and r2 values? I've attached the image you posted, this is the one I'm asking about.
aero

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

TE011 = 1.84088 GHz
TE012 = 2.45008 GHz  Q = 73,800
TE013 = 3.15166 GHz  Q=  70,000

using n=1
assuming flat ends

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes

Recommendations to place the RF feed based on free-space wavelength, IMHO, do NOT make sense.  Inside the cavity, there is no such free-space wavelength, instead there are wave-patterns with lengths governed by spherical Bessel functions and associated Legendre functions.

Kludgy spreadsheets based on drastic approximations that are unable to predict or even show the mode shapes,  unable to calculate the Q, unable to calculate the electromagnetic fields, and much less the wave-pattern wavelenghts inside the cavity are not an excuse to use the free-space wavelength.

To locate the antenna inside a Meep model based on such kludgy spreadsheets and approximation does not make sense to me:  look at the wavelengths of the wavepatterns inside Meep: they correspond to the spherical Bessel functions.  They do NOT correspond to the free space wavelength.


There is also misinterpretations concerning Shawyer and TE013. 

Shawyer used TE013 for the Flight Thruster because it operates at a much higher frequency (3.85 GHz instead of 2.45 GHz), not because of something having to do with volume.

On the contrary, Shawyer, instead of using longer lengths, has been doing all the contrary: it has moved to higher cone angles in a progressive way: using 30 degrees for the superconducting design.

Also for the superconducting design Shawyer has been moving to lower modes.
 
SPR Ltd, R. Shawyer, Demonstration 2.45 GHz TE012  19.28 degrees

SPR Ltd, R. Shawyer, Demonstration    3.85 GHz TE013  20.87 degrees

Yang has used TE012 in her tests, according to her paper.

Look at the attached picture of Shawyer's superconducting design: 

NO TE013 mode here

NO move of Shawyer towards longer lengths.  On the contrary, Shawyer has been moving to shorter lengths and higher cone angles.

Ditto for McCullloch who has been writing about the problems associated with long lengths.

Since Shell is going to be testing a design with long length and small cone angle (the Yang/Shell cone) it makes more sense that her alternate design should be a shorter length, high cone angle design.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 02:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .
I like this thought somewhat. More than once I've seen the relationship between this cavity and a particle accelerator. (Warning Warning Will Robinson, Engineer thinking physics alert)
Let's see, if the mode . . .
"creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)"

And then during a mode switch (which happens withing the cavity) it promptly decays into an evanescent wave into the small end of the cavity, the question would be... do the evanescent waves carry that increased spin and momentum imparting it into the small end? Let's not forget that an evanescent wave is a weird duck that is now only beginning to be understood.

I think it's entirely possible to pump up a photon and accelerate it towards the end of the cavity right at the mode decay. Will it violate CoM if the now massive photon imparts motion and apparent thrust in the small end direction? No.  What if I take those pumped up photons before I hit the endplate and decay them into evanescent waves which can't backscatter back into the large end which is the action that Conservation of Momentum uses.  Added: When a photon is emitted or absorbed, it transfers h bar of angular momentum and the associated energy is also transferred.

This is one reason I wanted the tuning chamber in the small end. And I like X_ray's idea of the trap and I can insert a probe into it to monitor energy conditions.


Reading two papers right now and here is one of my favorite things cropping up with the Golden Ratio....
"The universality of this phenomenon is revealed by analyzing, in detail, the cases corresponding to a) total internal reflection (TIR) b) waveguides c)optical fibers d) surface electromagnetic waves. We also show the existence of a unique criterion in TIR (”golden
ratio condition”) "  http://arxiv.org/abs/1504.06361

And the other which is kind of interesting...
http://onlyspacetime.com/QM-Foundation.pdf

I'm going to finish these up and clean up the mess I have in the shop (it wasn't me!).

I still need a Krell brain boost! To heck with those pesky monsters from the Id.

Shell
just added a thought...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 03:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418961#msg1418961">Quote from: Rodal on 08/23/2015 02:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418895#msg1418895">Quote from: aero on 08/23/2015 04:13 AM</a>
Dr. Rodal,
What were the dimensions of your spherical end model (of SeeShell's cavity) that resonates at 2.47 GHz? In particular, what were the r1 and r2 values? I've attached the image you posted, this is the one I'm asking about.
aero

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

TE011 = 1.84088 GHz
TE012 = 2.45008 GHz  Q = 73,800
TE013 = 3.15166 GHz  Q=  70,000

using n=1
assuming flat ends

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes

Recommendations to place the RF feed based on free-space wavelength, IMHO, do NOT make sense.  Inside the cavity, there is no such free-space wavelength, instead there are wave-patterns with lengths governed by spherical Bessel functions and associated Legendre functions.

Kludgy spreadsheets based on drastic approximations that are unable to predict or even show the mode shapes,  unable to calculate the Q, unable to calculate the electromagnetic fields, and much less the wave-pattern wavelenghts inside the cavity are not an excuse to use the free-space wavelength.

To locate the antenna inside a Meep model based on such kludgy spreadsheets and approximation does not make sense to me:  look at the wavelengths of the wavepatterns inside Meep: they correspond to the spherical Bessel functions.  They do NOT correspond to the free space wavelength.


There is also misinterpretations concerning Shawyer and TE013. 

Shawyer used TE013 for the Flight Thruster because it operates at a much higher frequency (3.85 GHz instead of 2.45 GHz), not because of something having to do with volume.

On the contrary, Shawyer, instead of using longer lengths, has been doing all the contrary: it has moved to higher cone angles in a progressive way: using 30 degrees for the superconducting design.

Also for the superconducting design Shawyer has been moving to lower modes.
 
SPR Ltd, R. Shawyer, Demonstration 2.45 GHz TE012  19.28 degrees

SPR Ltd, R. Shawyer, Demonstration    3.85 GHz TE013  20.87 degrees

Yang has used TE012 in her tests, according to her paper.

Look at the attached picture of Shawyer's superconducting design: 

NO TE013 mode here

NO move of Shawyer towards longer lengths.  On the contrary, Shawyer has been moving to shorter lengths and higher cone angles.

Ditto for McCullloch who has been writing about the problems associated with long lengths.

Since Shell is going to be testing a design with long length and small cone angle (the Yang/Shell cone) it makes more sense that her alternate design should be a shorter length, high cone angle design.

DITTO!

"Since Shell is going to be testing a design with long length and small cone angle (the Yang/Shell cone) it makes more sense that her alternate design should be a shorter length, high cone angle design."

I took several meep images (many say they are poo for detective work, I vehemently disagree) and scaled them to dimension, measured the center mode positions and compared that with the calculations used in other methods and there is a discrepancy between the two and your quite correct it is the spherical Bessel functions. You can see that in my layout of a overlay image.   Threw me for a loop. ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 03:28 PM

Thanks Shell for this paper:  http://arxiv.org/abs/1504.06361

Quote
We show that the Stokes parameters for
an evanescent wave unambiguously reveals that every fast
decaying evanescent wave is inherently circularly polarized
irrespective of how it originates. Furthermore, this
inherent handedness (spin) is locked to the direction of
propagation (momentum). This information hidden in
the Stokes parameters has been overlooked till date and
is in stark contrast to the existing knowledge on propagating
waves.


If given the Stokes parameters

(1cf3fd6cb08ae3b1dd900ee419a0bfe5.png)

(I is the total intensity of the beam, and p is the degree of polarization, constrained by 0 ≤ p ≤ 1.  The phase information of the polarized light is not recorded in the stokes parameters.  The phase information is lost in this description)

(8a07207c8a1fe1f20fc7169119c2e5a2.png)

(6d06e4a0a7234143afd2748766d30193.png)


one can solve for the spherical coordinates with the following equations

(0684ab975b0154b0cd5d1028b4405c6d.png)



(220px-Poincar%C3%A9_sphere.svg.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/23/2015 03:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418962#msg1418962">Quote from: SeeShells on 08/23/2015 02:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .
I like this thought somewhat. More than once I've seen the relationship between this cavity and a particle accelerator. (Warning Warning Will Robinson, Engineer thinking physics alert)
Let's see, if the mode . . .
"creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)"

And then during a mode switch (which happens withing the cavity) it promptly decays into an evanescent wave into the small end of the cavity, the question would be... do the evanescent waves carry that increased spin and momentum imparting it into the small end? Let's not forget that an evanescent wave is a weird duck that is now only beginning to be understood.

I think it's entirely possible to pump up a photon and accelerate it towards the end of the cavity right at the mode decay. Will it violate CoM if the now massive photon imparts motion and apparent thrust in the small end direction? No.  What if I take those pumped up photons before I hit the endplate and decay them into evanescent waves which can't backscatter back into the large end which is the action that Conservation of Momentum uses.  Added: When a photon is emitted or absorbed, it transfers h bar of angular momentum and the associated energy is also transferred.

This is one reason I wanted the tuning chamber in the small end. And I like X_ray's idea of the trap and I can insert a probe into it to monitor energy conditions.


Reading two papers right now and here is one of my favorite things cropping up with the Golden Ratio....
"The universality of this phenomenon is revealed by analyzing, in detail, the cases corresponding to a) total internal reflection (TIR) b) waveguides c)optical fibers d) surface electromagnetic waves. We also show the existence of a unique criterion in TIR (”golden
ratio condition”) "  http://arxiv.org/abs/1504.06361

And the other which is kind of interesting...
http://onlyspacetime.com/QM-Foundation.pdf

I'm going to finish these up and clean up the mess I have in the shop (it wasn't me!).

I still need a Krell brain boost! To heck with those pesky monsters from the Id.

Shell
just added a thought...

Would the opposite reaction going to heat create a measurable amount of heating?  Could it show up as an unusual amount if warping of the frustum?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Josave on 08/23/2015 04:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

Interesting configuration sugested in this work. Thanks for the paper, Mulletron!!!

Abstract. A set of thought experiments with guided waves (as the simplest example of spatially localized fields) shows that photons occupying a waveguide mode possess all the characteristics of nonzero inertial and gavitational rest mass. The corresponding quantity originates from the standing-wave component of the field and is merely an equivalent of the real energy from the `raking up' of zero-point vacuum fluctuations from all unbounded space. It is impossible to distinguish this quantity from the standard concept of mass. This conclusion is valid for photons of any real spatially bounded fields. Two different classes of resonances with boson- and fermion-like features arise in waveguide ring structures depending on their field topology. The heuristic prospects for these observations are assessed.

I wonder if the fermion configuration (a Moebius waveguide!!!) could make a big increase in inertial mass, maybe this is the effect in the Emdrive, because Shawyer says some initial acceleration is needed to observe the thrust.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/23/2015 04:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418963#msg1418963">Quote from: SeeShells on 08/23/2015 03:15 PM</a>
I took several meep images (many say they are poo for detective work, I vehemently disagree) and scaled them to dimension, measured the center mode positions and compared that with the calculations used in other methods and there is a discrepancy between the two and your quite correct it is the spherical Bessel functions. You can see that in my layout of a overlay image.   Threw me for a loop. ;)

As Rodal just explained, pay attention to NOT use the free-space wavelength for anything inside the frustum!
Yes at 2.45 GHz in free space the microwaves have a wavelength λ0 ≈ 12 cm.
But inside the cavity, the wavelength is larger. In your frustum, the wavelength at big end is λb ≈ 14 cm, and it is way greater at small end where λs ≈ 34 cm.

But this is from a kludgy spreadsheet ;) I am aware that this spreadsheet should only be used to make inroads into a problem and that some more advanced technique and simulation software should precisely compute data before building the real thing. I like to think of the spreadsheet as SketchUp for 3D modeling. It allows to get any idea very fast.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/23/2015 04:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .

I've referred to "squeezed light" a few times here. When the position is squeezed by the small end, the momentum increases, per Heisenberg's equation delta_x*delta_p = h/2. That causes momentum transfer at the small end to be larger than at the big end. How to prove it?

Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 04:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418968#msg1418968">Quote from: SteveD on 08/23/2015 03:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418962#msg1418962">Quote from: SeeShells on 08/23/2015 02:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .
I like this thought somewhat. More than once I've seen the relationship between this cavity and a particle accelerator. (Warning Warning Will Robinson, Engineer thinking physics alert)
Let's see, if the mode . . .
"creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)"

And then during a mode switch (which happens withing the cavity) it promptly decays into an evanescent wave into the small end of the cavity, the question would be... do the evanescent waves carry that increased spin and momentum imparting it into the small end? Let's not forget that an evanescent wave is a weird duck that is now only beginning to be understood.

I think it's entirely possible to pump up a photon and accelerate it towards the end of the cavity right at the mode decay. Will it violate CoM if the now massive photon imparts motion and apparent thrust in the small end direction? No.  What if I take those pumped up photons before I hit the endplate and decay them into evanescent waves which can't backscatter back into the large end which is the action that Conservation of Momentum uses.  Added: When a photon is emitted or absorbed, it transfers h bar of angular momentum and the associated energy is also transferred.

This is one reason I wanted the tuning chamber in the small end. And I like X_ray's idea of the trap and I can insert a probe into it to monitor energy conditions.


Reading two papers right now and here is one of my favorite things cropping up with the Golden Ratio....
"The universality of this phenomenon is revealed by analyzing, in detail, the cases corresponding to a) total internal reflection (TIR) b) waveguides c)optical fibers d) surface electromagnetic waves. We also show the existence of a unique criterion in TIR (”golden
ratio condition”) "  http://arxiv.org/abs/1504.06361

And the other which is kind of interesting...
http://onlyspacetime.com/QM-Foundation.pdf

I'm going to finish these up and clean up the mess I have in the shop (it wasn't me!).

I still need a Krell brain boost! To heck with those pesky monsters from the Id.

Shell
just added a thought...

Would the opposite reaction going to heat create a measurable amount of heating?  Could it show up as an unusual amount if warping of the frustum?
Great question....

You are correct evanescent waves even exist in a microwave oven's radiation heating a potato via the "imaginary" part of the refractive index.  http://www.met.reading.ac.uk/clouds/maxwell/microwave_oven.html

The key I think is that the evanescent decaying, into what? In free space? Evanescent... it means "tending to vanish" and a evanescent wave is what's called a "near-field wave" with its intensity showing exponential decay "without absorption".

This has been a red flag and since the evanescent wave is a standing wave, a static stress-energy or "pressure" gradient of an extraordinary nature what effects can we derive from it?. Quantum field theory's views are far field effects are manifestations of real photons, while near field effects are due to a mixture of real and virtual photons.

So you're asking me about a imaginary wave making virtual photons with extraordinary mass and momentum and spin generated by the frustum's actions decaying into nothingness? What could happen in the frustum's squeezing, decaying modes and energy? I think more than heat is being generated. But that is IMHO.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 04:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418965#msg1418965">Quote from: Rodal on 08/23/2015 03:28 PM</a>
Thanks Shell for this paper:  http://arxiv.org/abs/1504.06361

Quote
We show that the Stokes parameters for
an evanescent wave unambiguously reveals that every fast
decaying evanescent wave is inherently circularly polarized
irrespective of how it originates. Furthermore, this
inherent handedness (spin) is locked to the direction of
propagation (momentum). This information hidden in
the Stokes parameters has been overlooked till date and
is in stark contrast to the existing knowledge on propagating
waves.


If given the Stokes parameters

(1cf3fd6cb08ae3b1dd900ee419a0bfe5.png)

(I is the total intensity of the beam, and p is the degree of polarization, constrained by 0 ≤ p ≤ 1.  The phase information of the polarized light is not recorded in the stokes parameters.  The phase information is lost in this description)

(8a07207c8a1fe1f20fc7169119c2e5a2.png)

(6d06e4a0a7234143afd2748766d30193.png)


one can solve for the spherical coordinates with the following equations

(0684ab975b0154b0cd5d1028b4405c6d.png)



(220px-Poincar%C3%A9_sphere.svg.png)
Weird huh? I always though this.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 05:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418982#msg1418982">Quote from: flux_capacitor on 08/23/2015 04:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418963#msg1418963">Quote from: SeeShells on 08/23/2015 03:15 PM</a>
I took several meep images (many say they are poo for detective work, I vehemently disagree) and scaled them to dimension, measured the center mode positions and compared that with the calculations used in other methods and there is a discrepancy between the two and your quite correct it is the spherical Bessel functions. You can see that in my layout of a overlay image.   Threw me for a loop. ;)

As Rodal just explained, pay attention to NOT use the free-space wavelength for anything inside the frustum!
Yes at 2.45 GHz in free space the microwaves have a wavelength λ0 ≈ 12 cm.
But inside the cavity, the wavelength is larger. In your frustum, the wavelength at big end is λb ≈ 14 cm, and it is way greater at small end where λs ≈ 34 cm.

But this is from a kludgy spreadsheet ;) I am aware that this spreadsheet should only be used to make inroads into a problem and that some more advanced technique and simulation software should precisely compute data before building the real thing. I like to think of the spreadsheet as SketchUp for 3D modeling. It allows to get any idea very fast.

I fully agree with you !

I did not mean to disparage the spreadsheet.

TheTraveller's spreadsheet is a great contribution to the analysis and it should be part of the Engineering Design continuum:

* idea sketch
* back of the envelope calculation
* CAD drawing
* preliminary engineering analysis

All engineering and scientific organizations, operate like that.  Running the full analysis (using the exact solution or Finite Element or Finite Difference solutions) should only be done AFTER preliminary analysis using something like this spreadsheet.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/23/2015 05:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418959#msg1418959">Quote from: SeeShells on 08/23/2015 02:00 PM</a>
Very nice, you are dang good.. and fast! I was told that the loop should be just a little less than the chosen wavelength if we choose a loop. meep has a hard time modeling a loop and getting it to work right. aero needs to make sure he gets his phases correct for the two dipoles and not in phase.

OK, but if the perimeter of a loop antenna should be just below the wavelength, its diameter d = λ/π would be really tiny near the big base: I roughly calculated the loop diameter between 38 and 44 mm according to the position and frequency. So maybe two dipole antennas located further from each others, within the mode nodes, would be preferable?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/23/2015 05:16 PM
http://www.squeezed-light.de/

How can squeezed light be generated?
      
Squeezed light can be generated in nonlinear optical crystals. Ultraviolett or visible light, either pulsed or continuous wave, is focussed into a highly transparent but birefringent crystal, for example of magnesium-oxide doped lithium niobate. The light polarizes the crystal material which leads to an effect called parametric down-conversion (PDC) in which one pump photon produces two daughter photons of about twice the wavelength.


Now: about this empty metal can ...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 05:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418983#msg1418983">Quote from: WarpTech on 08/23/2015 04:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .

I've referred to "squeezed light" a few times here. When the position is squeezed by the small end, the momentum increases, per Heisenberg's equation delta_x*delta_p = h/2. That causes momentum transfer at the small end to be larger than at the big end. How to prove it?

Todd
I know you have squeezed that light. And there must be a carrier of that momentum xfer, right? "evanescent electromagnetic waves can carry four distinct momenta and three distinct spin angular momenta"

That is the big question, how do we measure near field virtual photons from a imaginary decaying wave function, imparting spin and momentum?
 
A thought has been banging around for a bit when I saw how you could reconstruct reflected evanescent waves. https://www.youtube.com/watch?v=xO6T1JCdJOQ
I think I can gain insight into the reconstruction from the tunneling. Not quite sure how but I'm thinking on it.

Shell

http://dml.riken.go.jp/images/pdf/ncomms4300rr.pdf
"Thus, we have shown that evanescent electromagnetic waves can carry four distinct
momenta and three distinct spin angular momenta. This is in sharp contrast with the single
momentum and single spin for a propagating plane wave (photons). Each of these momenta and spins has a clear physical meaning and result in a corresponding directly-observable force or torque on a probe Mie particle, as shown in Supplementary Figure 4. The field characteristics are given in Eqs. (2.12)–(2.18) and (3.14), whereas the forces and torques are described by Eqs. (3.6), (3.7), (3.11), and (3.12) in the ka 1 approximation. These results are summarized in Supplementary Table 1, which shows excellent agreement with the exact numerical simulations in Supplementary Figure 4.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 05:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418989#msg1418989">Quote from: flux_capacitor on 08/23/2015 05:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418959#msg1418959">Quote from: SeeShells on 08/23/2015 02:00 PM</a>
Very nice, you are dang good.. and fast! I was told that the loop should be just a little less than the chosen wavelength if we choose a loop. meep has a hard time modeling a loop and getting it to work right. aero needs to make sure he gets his phases correct for the two dipoles and not in phase.

OK, but if the perimeter of a loop antenna should be just below the wavelength, its diameter d = λ/π would be really tiny near the big base: I roughly calculated the loop diameter between 38 and 44 mm according to the position and frequency. So maybe two dipole antennas located further from each others, within the mode nodes, would be preferable?

YES! Shove that dipole right up the modes center. :D Otherwise the phase differentials between the mode being generated and the dipole antenna will lead to distortions and decreased Q. Dr. Rodal is absolutely right on this.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 05:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418982#msg1418982">Quote from: flux_capacitor on 08/23/2015 04:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418963#msg1418963">Quote from: SeeShells on 08/23/2015 03:15 PM</a>
I took several meep images (many say they are poo for detective work, I vehemently disagree) and scaled them to dimension, measured the center mode positions and compared that with the calculations used in other methods and there is a discrepancy between the two and your quite correct it is the spherical Bessel functions. You can see that in my layout of a overlay image.   Threw me for a loop. ;)

As Rodal just explained, pay attention to NOT use the free-space wavelength for anything inside the frustum!
Yes at 2.45 GHz in free space the microwaves have a wavelength λ0 ≈ 12 cm.
But inside the cavity, the wavelength is larger. In your frustum, the wavelength at big end is λb ≈ 14 cm, and it is way greater at small end where λs ≈ 34 cm.

But this is from a kludgy spreadsheet ;) I am aware that this spreadsheet should only be used to make inroads into a problem and that some more advanced technique and simulation software should precisely compute data before building the real thing. I like to think of the spreadsheet as SketchUp for 3D modeling. It allows to get any idea very fast.

This had me scratching my head for the longest time. Throwing in the black magic of antenna design,  then the knuckle draggers ball peen hammers tuning a waveguide and shove it into a cone with it's head cut off and now you're gonna tell me it's all gonna fly!?!?!?

I have to chuckle at some who think it's so easy to do it right.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/23/2015 07:46 PM
Interesting web page: http://www.k0bg.com/myths.html

"Coil Q Myth

Designing mobile loading coils (they're really inductors) requires both science, and a goodly dose of practicality. It is also a discipline where bigger isn't always better! Here are a few salient points to keep in mind.

As coils get larger in diameter, there is more distributed capacitance, and more resistive wire losses, both of which reduces Q. Thus larger coils have a lower self-resonant point. Above the self-resonant point, a coil acts more like a lossy capacitor, than a coil. Further, anything placed within the coils electrical field will lower the Q. Large metal end caps are an example. And, the size of the wire, the plating on the wire if any, the number of turns per inch (tpi), and the coil support structure (coil form), all have an effect on the (assembled) Q.

Lower frequencies require more inductance in the coil, upper frequencies less inductance."

"The SWR vs. Resonance Myth
A very common belief is that the lowest VSWR point is always the exact resonant point. This is a myth! For example, an unmatched, HF mobile antenna, of decent quality, will have an average input impedance of ≈25 ohms at resonance. This represents an VSWR of 2:1. This fact can be easily demonstrated by measuring the input impedance with an antenna analyzer."

see diagram

-------------------------------------------------------------------------------------------------------------------------------------
Small antennas/loops: http://www.qsl.net/va3iul/Antenna/Small_Antennas_for_High_Frequencies/Small_Antennas_for_High_Frequencies.pdf
"The difference between Resonators and Antennas is that a good resonator has a High Q-factor, whereas a good antenna has a Low Q-factor. "

"For example a λ/10 diameter loop would have A = π(λ/20), and the radiation resistance
(Rr) is found to be 1.92 ohms.
The actual feedpoint impedance will include the resistive loss of the conductor (with skin
effect), plus the inductance of the loop, which will have a result in range of 3.0 +j800 ohms.

The radiation pattern and gain are similar to the λ/10 short dipole.
Current distribution is nearly uniform on a
Small Loop antenna.
Typically, a Small-Loop antenna may be able to radiate only a few percent of the power that
comes from the transmitter.
"
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/23/2015 08:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418961#msg1418961">Quote from: Rodal on 08/23/2015 02:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418895#msg1418895">Quote from: aero on 08/23/2015 04:13 AM</a>
Dr. Rodal,
What were the dimensions of your spherical end model (of SeeShell's cavity) that resonates at 2.47 GHz? In particular, what were the r1 and r2 values? I've attached the image you posted, this is the one I'm asking about.
aero

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

TE011 = 1.84088 GHz
TE012 = 2.45008 GHz  Q = 73,800
TE013 = 3.15166 GHz  Q=  70,000

using n=1
assuming flat ends

Actually, you would be well advised to make the length somewhat smaller than 0.163 meters, so that you can tune it with the longer length of the cylindrical extension. 

Remember that using the cylindrical extension to increase the length of the cavity, will lower the natural frequencies of given mode shapes

Recommendations to place the RF feed based on free-space wavelength, IMHO, do NOT make sense.  Inside the cavity, there is no such free-space wavelength, instead there are wave-patterns with lengths governed by spherical Bessel functions and associated Legendre functions.

Kludgy spreadsheets based on drastic approximations that are unable to predict or even show the mode shapes,  unable to calculate the Q, unable to calculate the electromagnetic fields, and much less the wave-pattern wavelenghts inside the cavity are not an excuse to use the free-space wavelength.

To locate the antenna inside a Meep model based on such kludgy spreadsheets and approximation does not make sense to me:  look at the wavelengths of the wavepatterns inside Meep: they correspond to the spherical Bessel functions.  They do NOT correspond to the free space wavelength.


There is also misinterpretations concerning Shawyer and TE013. 

Shawyer used TE013 for the Flight Thruster because it operates at a much higher frequency (3.85 GHz instead of 2.45 GHz), not because of something having to do with volume.

On the contrary, Shawyer, instead of using longer lengths, has been doing all the contrary: it has moved to higher cone angles in a progressive way: using 30 degrees for the superconducting design.

Also for the superconducting design Shawyer has been moving to lower modes.
 
SPR Ltd, R. Shawyer, Demonstration 2.45 GHz TE012  19.28 degrees

SPR Ltd, R. Shawyer, Demonstration    3.85 GHz TE013  20.87 degrees

Yang has used TE012 in her tests, according to her paper.

Look at the attached picture of Shawyer's superconducting design: 

NO TE013 mode here

NO move of Shawyer towards longer lengths.  On the contrary, Shawyer has been moving to shorter lengths and higher cone angles.

Ditto for McCullloch who has been writing about the problems associated with long lengths.

Since Shell is going to be testing a design with long length and small cone angle (the Yang/Shell cone) it makes more sense that her alternate design should be a shorter length, high cone angle design.

The wave-pattern wavelengths for TE012 = 2.45008 GHz for these dimensions:

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

has a first absolute value maximum, for the wave-pattern next to the small base that occurs at:

28.1465% of the distance between the bases, measuring from the small base

which for  axial length=0.163 m

0.0458789 m axial distance from the small base

this is where I think the antenna should be located when locating the antenna near the small base

____________________________________________________________________________________

the next absolute value maximum, for the wave-pattern next to the big base occurs at:

77.3927% of the distance between the bases, measuring from the small base

or equivalently

22.6073% of the distance between the bases, measuring from the big base

which for  axial length=0.163 m means

0.12615 m axial distance from the small base , or equivalently

0.0368499 m axial distance from the big base

this is where I think the antenna should be located when locating the antenna near the big base

____________________________________________________________________________________

Thus, optimal locations are NOT at 1/4 of the axial distance, rather the optimal location near the small base is further away, at 28.1465% of the distance from the small base, while the optimal location near the big base is closer to the big base, at 22.6073% of the distance from the small base

These optimal distances for TE012 are approximately +/- 10% different from the 1/4 distance

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/23/2015 08:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037">Quote from: Rodal on 08/23/2015 08:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418961#msg1418961">Quote from: Rodal on 08/23/2015 02:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418895#msg1418895">Quote from: aero on 08/23/2015 04:13 AM</a>

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

TE011 = 1.84088 GHz
TE012 = 2.45008 GHz  Q = 73,800
TE013 = 3.15166 GHz  Q=  70,000
The wave-pattern wavelengths for TE012 = 2.45008 GHz for these dimensions:

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

has a first absolute value maximum, for the wave-pattern next to the small base that occurs at:

28.1465% of the distance between the bases, measuring from the small base

which for  axial length=0.163 m

0.0458789 m axial distance from the small base

this is where I think the antenna should be located when locating the antenna near the small base

____________________________________________________________________________________

the next absolute value maximum, for the wave-pattern next to the big base occurs at:

77.3927% of the distance between the bases, measuring from the small base

or equivalently

22.6073% of the distance between the bases, measuring from the big base

which for  axial length=0.163 m means

0.12615 m axial distance from the small base , or equivalently

0.0368499 m axial distance from the big base

this is where I think the antenna should be located when locating the antenna near the big base

____________________________________________________________________________________

Thus, optimal locations are NOT at 1/4 of the axial distance, rather the optimal location near the small base is further away, at 28.1465% of the distance from the small base, while the optimal location near the big base is closer to the big base, at 22.6073% of the distance from the small base

These optimal distances for TE012 are approximately +/- 10% different from the 1/4 distance

A lot closer measurements than I got, very nice Dr. Rodel.... very nice.

This is very important as to why we cannot hold and maintain a good Q and why others have had a issue with even waveguide injection. I'll be very interested in seeing what aero gets when he places the dipoles in this region.

Shell

PS: aero how do you make sure your antennas are out of phase with your feeds?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/23/2015 10:33 PM
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/23/2015 10:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418929#msg1418929">Quote from: Mezzenile on 08/23/2015 07:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418911#msg1418911">Quote from: VAXHeadroom on 08/23/2015 05:53 AM</a>
No way is a parabolic airplane flight loop long enough to do this test and see anything with a thrust less than about 1N.
Credentials to say this: I've done 160 parabolas testing a free-flying device...(last summer).

Edit: I'll modify that - you'd need about 0.1m/s2 acceleration to detect the change in the short zero-g time, so it would depend on the mass of the test device, but I'd think it would be difficult to get under several kg.

If I consider a test device weighting 100 Kg (including cavity, DC Li-Ion battery, RF harness, source and power amplifier (TWT + EPC), hold-on and release mechanism..) with a thrust of 0.1 N, this would lead to an acceleration gamma of 0.001 m/s² and so to a total displacement of 0.2 m for a test duration t of 20 seconds (1/2 gamma t²). Dont'you think that this displacement could be properly observed if we use a small vaccum test chamber with observation capability surrounding at 30 cm distance the test device ?

Of course we should have calibration parabolic flights without thrust to  evaluate the 0-thrust displacement.

There is also the possibility to use a vaccuum drop tower which offers weightless or microgravity environment for a duration of 5.18 seconds (NASA data : http://facilities.grc.nasa.gov/zerog/ (http://facilities.grc.nasa.gov/zerog/)). The accurate measure of the free fall trajectory versus time should provide the thrust characteristics versus time.

I hire you for the flight test operation as you seem well experimented in this matter  ;) !! (nausea-free prooved   :D ?)

I had a blast doing the flights and would go again in a heartbeat.  We had 30+ people on the plane for 4 flight days and nobody got sick.

To test a free-flying object in the plane you have to release it near the center-line of the vehicle once the zero G is established.  No way you'd want to try that with 100kg!!  Needs to be more like 10...  And you don't get the full 20 seconds for a free-flyer.  Remember, you're really in a plane that's falling out of the sky, controlled by a pilot.  They have to actively try to fly the fuselage around the centerline of the mass, but they will tend to drift a bit, so your device will - no matter how carefully you release it - drift toward one of the walls and eventually impact it.  10-15 seconds is what you actually get before touching the wall/ceiling/floor.  And then you have to catch the device and lower it to the floor as the pilot pulls up (the gravity comes back 'on' somewhat gradually, 3-5 seconds).  So again the 100kg is too much for a free-flyer.

Maybe if you constrained it to fly down a tube...but then the tube has to have all kinds of safety constraints (they're really picky about safety obviously!).  It's a hard problem, one I'd LOVE to work on!! :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 08/23/2015 11:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y

Just wondering if you are going to attach grid paper to the laser target to more easily observe/measure any deflection?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/23/2015 11:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419058#msg1419058">Quote from: Bob Woods on 08/23/2015 11:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y

Just wondering if you are going to attach grid paper to the laser target to more easily observe/measure any deflection?
Good idea...I'll print one up before tuesday

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Josave on 08/23/2015 11:38 PM
From the same author of the paper found by Mulletron, this work “On the analogy between Hawking radiation and nonlinear optical process of subharmonic generation (waveguide model of a black hole)”

http://iopscience.iop.org/1063-7818/42/7/A17

seems to be the brick that McCulloch model needs to explain why Unruh radiation (=Hawking radiation) can be created inside a nonlinear waveguide process, say mode conversion:

“…let the primary photons, belonging to the TM02 mode with the critical frequency p w02 = 2pc/1.14R and the mass p M02 = 2pћ/1.14cR, decay into the secondary photon pairs, belonging to the TM01 mode with the critical frequency s w01 = 2pc/2.61R and the mass s M01 = 2pћ/2.61cR, in a waveguide of circular cross section with radius R….”

“…the waveguide model of a black hole, which operates the photons with the only frequency w, can be greatly increased due to abandonment of monochromaticity and due to consideration of the photon ensemble of a wide range of frequencies. In this case, all the photons of the ensemble must reach the horizon at the same height and gravitational potential increment DY, i.e., according to (7) all the photons of the ensemble must have a common ratio wmv /w =Mmvc2/ћw, which requires obvious individual choice of the mode for each photonic waveguide…”

This seems to model at least one minimum effect that we can expect and could be measured in the current experiments: the “center of mass” of the Emdrive should move to the big end, leading to a step movement to that side

Questions remains to engineer a system that, or repeat this process in a Woodward see-saw model, or, who knows how, lowers the mass of the photons due to their interaction with the rest of the bodies seen by their Rindler horizon outside the cavity, as MiHsC theory inspired in Mach principle proposes.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/24/2015 12:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418929#msg1418929">Quote from: Mezzenile on 08/23/2015 07:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418911#msg1418911">Quote from: VAXHeadroom on 08/23/2015 05:53 AM</a>
No way is a parabolic airplane flight loop long enough to do this test and see anything with a thrust less than about 1N.
Credentials to say this: I've done 160 parabolas testing a free-flying device...(last summer).

Edit: I'll modify that - you'd need about 0.1m/s2 acceleration to detect the change in the short zero-g time, so it would depend on the mass of the test device, but I'd think it would be difficult to get under several kg.

If I consider a test device weighting 100 Kg (including cavity, DC Li-Ion battery, RF harness, source and power amplifier (TWT + EPC), hold-on and release mechanism..) with a thrust of 0.1 N, this would lead to an acceleration gamma of 0.001 m/s² and so to a total displacement of 0.2 m for a test duration t of 20 seconds (1/2 gamma t²). Dont'you think that this displacement could be properly observed if we use a small vaccum test chamber with observation capability surrounding at 30 cm distance the test device ?

Of course we should have calibration parabolic flights without thrust to  evaluate the 0-thrust displacement.

There is also the possibility to use a vaccuum drop tower which offers weightless or microgravity environment for a duration of 5.18 seconds (NASA data : http://facilities.grc.nasa.gov/zerog/ (http://facilities.grc.nasa.gov/zerog/)). The accurate measure of the free fall trajectory versus time should provide the thrust characteristics versus time.

I hire you for the flight test operation as you seem well experimented in this matter  ;) !! (nausea-free prooved   :D ?)

If you could get the device to behave that way in parabolic flight, why could you not measure the thrust of the same device in the lab?  What effect are we eliminating by putting in in free fall?  Why not just put it on a air bearing floor?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/24/2015 12:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y

Can you set up a second camera watching the frustum and rig while the first looks at the paper?  Not perfect, but the first thing I'd think of with the camera only recording the laser moving is that you might be physically manipulating the rig.  Given that the lights are going to be off, I realize that this would be difficult.  Maybe some form of thermal camera?  Then again I can understand just wanting the verify that the thing is giving some kind of detectable result before fiddling with it more.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/24/2015 01:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419059#msg1419059">Quote from: rfmwguy on 08/23/2015 11:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419058#msg1419058">Quote from: Bob Woods on 08/23/2015 11:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y

Just wondering if you are going to attach grid paper to the laser target to more easily observe/measure any deflection?
Good idea...I'll print one up before tuesday

Can you deduce thrust from the laser spot displacement?  Without the mirror it seems straightforward, with it seems more problematic.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 01:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419071#msg1419071">Quote from: SteveD on 08/24/2015 12:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y

Can you set up a second camera watching the frustum and rig while the first looks at the paper?  Not perfect, but the first thing I'd think of with the camera only recording the laser moving is that you might be physically manipulating the rig.  Given that the lights are going to be off, I realize that this would be difficult.  Maybe some form of thermal camera?  Then again I can understand just wanting the verify that the thing is giving some kind of detectable result before fiddling with it more.

I have a suggestion that might Kill three birds with one stone rfmwguy.

Take your camera and shoot the backside of the graph paper. Easier for your camera to see the red dot without blossoming out from sensitivity to the red light.

You can see the device and the paper in one view if it's set up right.

On the front of the paper run two strips of electrical tape up and down separated by a small gap maybe 1/4 inch. It will help define the movement. Like a vertical bar graph display and make your lines heavy horizontally when you do the graph paper.

One other thing, twist the power leads together and the heater leads together, you'll reduce noise and cancel AC effects the leads may carry.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 08/24/2015 01:34 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419059#msg1419059">Quote from: rfmwguy on 08/23/2015 11:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419058#msg1419058">Quote from: Bob Woods on 08/23/2015 11:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y

Just wondering if you are going to attach grid paper to the laser target to more easily observe/measure any deflection?
Good idea...I'll print one up before tuesday
A second thought is that with the current setup, the large end is at the top. The discussion on the site has stated that the small end is where the force will occur. Since the small end of the frustum is at the bottom I see a potential bias.

Even though you are using a mesh containment, the larger diameter at the top presents a significantly greater surface area. If there are thermal effects. The rising of hot air against that diameter may reduce/offset any actual force generated, especially if it is very small.

I see from your setup that relocating the electrical connections is not trivial. You may want to consider flipping the frustum after your first set of tests.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 01:43 AM
Thanks for all the good ideas. I will take as many as I can into consideration on Tuesday morning before the 2 pm flight test. Keep the ideas coming, this is a collaboration...always has been.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 02:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419080#msg1419080">Quote from: rfmwguy on 08/24/2015 01:43 AM</a>
Thanks for all the good ideas. I will take as many as I can into consideration on Tuesday morning before the 2 pm flight test. Keep the ideas coming, this is a collaboration...always has been.
You're very welcome. Videoing the laser behind the paper with black electrical tape defining the graph works well. I even tried a little vegetable oil on the paper  to increase light transmission.

Nice work.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/24/2015 03:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419077#msg1419077">Quote from: SeeShells on 08/24/2015 01:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419071#msg1419071">Quote from: SteveD on 08/24/2015 12:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
(video snip)

Can you set up a second camera watching the frustum and rig while the first looks at the paper?  Not perfect, but the first thing I'd think of with the camera only recording the laser moving is that you might be physically manipulating the rig.  Given that the lights are going to be off, I realize that this would be difficult.  Maybe some form of thermal camera?  Then again I can understand just wanting the verify that the thing is giving some kind of detectable result before fiddling with it more.

I have a suggestion that might Kill three birds with one stone rfmwguy.

Take your camera and shoot the backside of the graph paper. Easier for your camera to see the red dot without blossoming out from sensitivity to the red light.

You can see the device and the paper in one view if it's set up right.

On the front of the paper run two strips of electrical tape up and down separated by a small gap maybe 1/4 inch. It will help define the movement. Like a vertical bar graph display and make your lines heavy horizontally when you do the graph paper.

One other thing, twist the power leads together and the heater leads together, you'll reduce noise and cancel AC effects the leads may carry.

I also suggested twisting the leads, but I'm not sure the insulation on the red wire is actually 4000V rated. If not, don't do it, it may breakdown through to the other wires. I'm not sure that terminal block is good for 4000V either. Humidity may cause it to arc to ground.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 03:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419085#msg1419085">Quote from: WarpTech on 08/24/2015 03:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419077#msg1419077">Quote from: SeeShells on 08/24/2015 01:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419071#msg1419071">Quote from: SteveD on 08/24/2015 12:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
(video snip)

Can you set up a second camera watching the frustum and rig while the first looks at the paper?  Not perfect, but the first thing I'd think of with the camera only recording the laser moving is that you might be physically manipulating the rig.  Given that the lights are going to be off, I realize that this would be difficult.  Maybe some form of thermal camera?  Then again I can understand just wanting the verify that the thing is giving some kind of detectable result before fiddling with it more.

I have a suggestion that might Kill three birds with one stone rfmwguy.

Take your camera and shoot the backside of the graph paper. Easier for your camera to see the red dot without blossoming out from sensitivity to the red light.

You can see the device and the paper in one view if it's set up right.

On the front of the paper run two strips of electrical tape up and down separated by a small gap maybe 1/4 inch. It will help define the movement. Like a vertical bar graph display and make your lines heavy horizontally when you do the graph paper.

One other thing, twist the power leads together and the heater leads together, you'll reduce noise and cancel AC effects the leads may carry.

I also suggested twisting the leads, but I'm not sure the insulation on the red wire is actually 4000V rated. If not, don't do it, it may breakdown through to the other wires. I'm not sure that terminal block is good for 4000V either. Humidity may cause it to arc to ground.
Todd
Have to confess, I did a test firing this AM. No arcs on terminal. Humidity was low. Will measure that on Tuesday. Yes, I'm avoiding anything next to hv insulation. Proper wire for this is silicone insulated...like on oscilloscope test lead, only heavier guage. Could not locate easily.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/24/2015 04:01 AM
I'm assuming your pre-prep includes squared paper and calibration marks denoting actual mg-wt.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/24/2015 07:30 AM
Rfmwguy - good luck, I'm definitely excited to see your results!

On another topic, a few pages back there was a discussion on using "WiFi" mains power as an alternative to batteries on a rotary test rig, which seemed to conclude that movement of the receiver during a test would make that idea impractical.

However, I couldn't see why the receiver should not be mounted on the axis of rotation, and thereby remain still. I know this is obvious, but I was surprised I didn't see it mentioned.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/24/2015 11:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418962#msg1418962">Quote from: SeeShells on 08/23/2015 02:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .
I like this thought somewhat. More than once I've seen the relationship between this cavity and a particle accelerator. (Warning Warning Will Robinson, Engineer thinking physics alert)
Let's see, if the mode . . .
"creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)"

And then during a mode switch (which happens withing the cavity) it promptly decays into an evanescent wave into the small end of the cavity, the question would be... do the evanescent waves carry that increased spin and momentum imparting it into the small end? Let's not forget that an evanescent wave is a weird duck that is now only beginning to be understood.

I think it's entirely possible to pump up a photon and accelerate it towards the end of the cavity right at the mode decay. Will it violate CoM if the now massive photon imparts motion and apparent thrust in the small end direction? No.  What if I take those pumped up photons before I hit the endplate and decay them into evanescent waves which can't backscatter back into the large end which is the action that Conservation of Momentum uses.  Added: When a photon is emitted or absorbed, it transfers h bar of angular momentum and the associated energy is also transferred.

This is one reason I wanted the tuning chamber in the small end. And I like X_ray's idea of the trap and I can insert a probe into it to monitor energy conditions.


Reading two papers right now and here is one of my favorite things cropping up with the Golden Ratio....
"The universality of this phenomenon is revealed by analyzing, in detail, the cases corresponding to a) total internal reflection (TIR) b) waveguides c)optical fibers d) surface electromagnetic waves. We also show the existence of a unique criterion in TIR (”golden
ratio condition”) "  http://arxiv.org/abs/1504.06361

And the other which is kind of interesting...
http://onlyspacetime.com/QM-Foundation.pdf

I'm going to finish these up and clean up the mess I have in the shop (it wasn't me!).

I still need a Krell brain boost! To heck with those pesky monsters from the Id.

Shell
just added a thought...

I'm trying to see a mode conversion in the flat ends cavity, and associated with that a electromagnetic center of mass oscillation.
A spatial oscillation of fields energy distribuition is a scenarium of the called bloch wave oscillation wich arises in some configurations of gain/loss Spatial symmetry ( PT symmetry) plus a "linear potential" ( a gradient of contitutives properties of medium).
A oscillation of center of mass can be viewd as a oscillation of rest reference frame too, and like a foucault pendulum where occurs a rotation of oscilattion plane because of a berry phase, I'm curious if there is a berry phase causing a lorentz boost ( a space-time hyperbolic rotation).
But both, PT symmetry breaking (hamiltonian exceptional points study), and berry phases ( topological momentum space curvature effects)  has a very hard math description.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 01:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419090#msg1419090">Quote from: deltaMass on 08/24/2015 04:01 AM</a>
I'm assuming your pre-prep includes squared paper and calibration marks denoting actual mg-wt.
Close, I'm going to play around with it a bit on tuesday morning to get the best results. Probably use another pinhole in front of the laser and a vertical alignment of pinholes, every mm, on a black target...then video from behind. I'll add calibrated weights to the beam and note deflection. I like shell's bar-graph analogy. My gut feel is resolution of only about 10 mg or so for this home-brew setup. Actually, force in this region is of lettle interest to me anyway.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/24/2015 01:57 PM
Good stuff. I reckon your chief artifactual source is going to be convective thermal in nature. It's tough to provide an estimate of its magnitude.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 02:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419198#msg1419198">Quote from: rfmwguy on 08/24/2015 01:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419090#msg1419090">Quote from: deltaMass on 08/24/2015 04:01 AM</a>
I'm assuming your pre-prep includes squared paper and calibration marks denoting actual mg-wt.
Close, I'm going to play around with it a bit on tuesday morning to get the best results. Probably use another pinhole in front of the laser and a vertical alignment of pinholes, every mm, on a black target...then video from behind. I'll add calibrated weights to the beam and note deflection. I like shell's bar-graph analogy. My gut feel is resolution of only about 10 mg or so for this home-brew setup. Actually, force in this region is of lettle interest to me anyway.
Try a normal mirror and a pinhole lens in front of the laser, you'll get a very nice laser dot with little or no fringing. I'm using the red laser I got off ebay (for like 20 bucks I got 3, red, green and blue (more like UV visible)). The red shows up in the video better BTW.

If you have these three lasers, take one and mount it on the mirror stand shining on a single spot on the graph paper. Then you have a base for seeing vibration changes in your garage floor. Pinhole lens that too.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 02:37 PM
JBtek® HDMI / VGA Digital LCD Driver Board with 9" TFT LCD for Raspberry Pi

DEWALT DW5576 3/8-Inch Diamond Drill Bit 2 Arriving today by 8pm

compass magnetometer IC, I2C, HMC5883L, PCB module, for Arduino microcontroller
( 141332300714 )
Estimated delivery Mon, Aug 24 - Mon, Aug 31

Got the XYZ accelerometer already.

Seems like it's taking forever! I'm getting so antsy to test!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 02:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419215#msg1419215">Quote from: deltaMass on 08/24/2015 01:57 PM</a>
Good stuff. I reckon your chief artifactual source is going to be convective thermal in nature. It's tough to provide an estimate of its magnitude.
Yes, there is a 12 in square copper board directly above the magnetron, where heat will rise around it. This is about the only variable to contend with as I've tried to use non magnetic materials on the fulcrum. Any downward force will be working agains this lift. So if I see anything, I'll invert the engine, measure upwards force then subtract the difference. This should approximate thermal lift.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: watermod on 08/24/2015 02:56 PM
SeeShells et al.   A short distance from Fermilab is a good source for strange bits of scientific surplus and junk.   Lots of odd front surface mirror bits, pin holes and the like.   http://www.sciplus.com/ (http://www.sciplus.com/)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 03:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419228#msg1419228">Quote from: watermod on 08/24/2015 02:56 PM</a>
SeeShells et al.   A short distance from Fermilab is a good source for strange bits of scientific surplus and junk.   Lots of odd front surface mirror bits, pin holes and the like.   http://www.sciplus.com/ (http://www.sciplus.com/)
ACK! Be back after I dig through it. Love it, I'm a kid in a candy store!

Thanks watermod!
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 03:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419223#msg1419223">Quote from: SeeShells on 08/24/2015 02:37 PM</a>
JBtek® HDMI / VGA Digital LCD Driver Board with 9" TFT LCD for Raspberry Pi

DEWALT DW5576 3/8-Inch Diamond Drill Bit 2 Arriving today by 8pm

compass magnetometer IC, I2C, HMC5883L, PCB module, for Arduino microcontroller
( 141332300714 )
Estimated delivery Mon, Aug 24 - Mon, Aug 31

Got the XYZ accelerometer already.

Seems like it's taking forever! I'm getting so antsy to test!

Shell
I'd love to see some pics or vids of your work in progress. C'mon, shell...jump in, the water's fine.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 04:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419234#msg1419234">Quote from: rfmwguy on 08/24/2015 03:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419223#msg1419223">Quote from: SeeShells on 08/24/2015 02:37 PM</a>
JBtek® HDMI / VGA Digital LCD Driver Board with 9" TFT LCD for Raspberry Pi

DEWALT DW5576 3/8-Inch Diamond Drill Bit 2 Arriving today by 8pm

compass magnetometer IC, I2C, HMC5883L, PCB module, for Arduino microcontroller
( 141332300714 )
Estimated delivery Mon, Aug 24 - Mon, Aug 31

Got the XYZ accelerometer already.

Seems like it's taking forever! I'm getting so antsy to test!

Shell
I'd love to see some pics or vids of your work in progress. C'mon, shell...jump in, the water's fine.
Ok will do. I'll get my camera back from a friend who borrowed it for wedding pics this weekend and take some for ya. News and pics at 9. ;)

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/24/2015 04:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y
Looks very nice :)
Do you have an idea how the current resonance frequency of your target mode is with the spherical copper mesh? (How much lower compared with the flat as calculated before?)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/24/2015 04:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419055#msg1419055">Quote from: VAXHeadroom on 08/23/2015 10:37 PM</a>
I had a blast doing the flights and would go again in a heartbeat.  We had 30+ people on the plane for 4 flight days and nobody got sick.

To test a free-flying object in the plane you have to release it near the center-line of the vehicle once the zero G is established.  No way you'd want to try that with 100kg!!  Needs to be more like 10...  And you don't get the full 20 seconds for a free-flyer.  Remember, you're really in a plane that's falling out of the sky, controlled by a pilot.  They have to actively try to fly the fuselage around the centerline of the mass, but they will tend to drift a bit, so your device will - no matter how carefully you release it - drift toward one of the walls and eventually impact it.  10-15 seconds is what you actually get before touching the wall/ceiling/floor.  And then you have to catch the device and lower it to the floor as the pilot pulls up (the gravity comes back 'on' somewhat gradually, 3-5 seconds).  So again the 100kg is too much for a free-flyer.

Maybe if you constrained it to fly down a tube...but then the tube has to have all kinds of safety constraints (they're really picky about safety obviously!).  It's a hard problem, one I'd LOVE to work on!! :)

Ok, I understand that it could be really difficult to get any accurate displacement measurement in vaccuum during a parabolic flight.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419069#msg1419069">Quote from: Prunesquallor on 08/24/2015 12:42 AM</a>
If you could get the device to behave that way in parabolic flight, why could you not measure the thrust of the same device in the lab?  What effect are we eliminating by putting in in free fall?  Why not just put it on a air bearing floor?

I agree that in principle the initial thrust can be measured on a static test bench. But I would like to measure precisely how this thrust varies when the speed of the cavity increases under its action. There is a strong rationale to think that the thrust should decrease (or the RF power consumption of the cavity increase ...)  when the speed increases.

For what concern the use of a air bearing floor, I suppose that it entails to operate at ambiant pressure and that the unevitable air resistance would too much perturbate the dynamic of the experience.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: BL on 08/24/2015 04:31 PM
Re rfmwguy Post #991

If you are still looking for HV wire, McMaster-Carr has plenty:

http://www.mcmaster.com/#high-voltage-wire/=ymwsh6

It starts at 10 KV rating, goes up to 42 KV, and is available in pieces as short as 5' @ under $2/ft for the lower voltage/smaller conductor stuff.  At 4 KV, I wouldn't expect you would need a very large conductor to handle the magnetron current.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 06:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419170#msg1419170">Quote from: Ricvil on 08/24/2015 11:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418962#msg1418962">Quote from: SeeShells on 08/23/2015 02:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418940#msg1418940">Quote from: CW on 08/23/2015 09:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418900#msg1418900">Quote from: Mulletron on 08/23/2015 04:37 AM</a>
More on photon "mass" within waveguides:

http://iopscience.iop.org/1063-7869/40/3/A05

These ain't your usual garden variety photons when they get confined it seems.

AFAIK, confined particles are represented by standing waves. Vice versa, any standing wave is then equivalent to a confined particle including properties such as mass etc. Depending on chosen mode(s), the standing wave distribution within the waveguide could then represent not just one single confined particle, but actually a sort of atomic lattice of dynamically created massive particle equivalents. Following this line of thought, there is maybe an optimal standing wave distribution within any waveguide that maximizes this effect, i.e. creating a maximally massive particle equivalent.

If I understood Dr. Rodal correctly, then there is only an observable stress/force imbalance if the RF feed is on? I'm getting the impression that what's actually happening in this device is this:

-   Incoming RF energy creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)
-   Since the location as well as the impulse of this particle structure are smeared according to Heisenberg, this dynamical particle structure statistically squeezes more against the smaller waveguide end volume than it squeezes against the larger waveguide end volume or (!) vice versa - depending on the topology of the dynamically created mode dependent massive particle structure
-   This squeeze stress shows up as a real net force against the small end or (!) the large end, depending on mode dependent particle structure topology
-   The imbalanced Heisenberg squeeze-stress-imparted impulse on the waveguide finds its balance by energy conversion into heat (= chaotic local impulse) within the waveguide's crystal lattice
-   The active RF feed is like a lifeline to the dynamic process of creating and upholding an energy delta that gives the confined particle structure its 'life'.
-   I'm sure that MEEP is not made to take Heisenberg's uncertainty principle into consideration when simulating Maxwell's equations. Wherever the dynamic particle structure is squeezed within a real cavity .. EM stress and forces are bound to come into existence. This might be key to understand what's happening here.

At least that's how my naive engineering mind imagines what's going on. Comments are welcome :) .
I like this thought somewhat. More than once I've seen the relationship between this cavity and a particle accelerator. (Warning Warning Will Robinson, Engineer thinking physics alert)
Let's see, if the mode . . .
"creates standing wave distributions, which are equivalent to confined massive particles within the waveguide
-   Depending on the standing wave distributions, they represent an actual massive particle structure with varying topology
-   If this massive particle structure can be regarded as an actual massive confined particle structure, then the Heisenberg uncertainty principle should apply, too (as does for any other real particle, no matter if (pseudo) static or dynamic)"

And then during a mode switch (which happens withing the cavity) it promptly decays into an evanescent wave into the small end of the cavity, the question would be... do the evanescent waves carry that increased spin and momentum imparting it into the small end? Let's not forget that an evanescent wave is a weird duck that is now only beginning to be understood.

I think it's entirely possible to pump up a photon and accelerate it towards the end of the cavity right at the mode decay. Will it violate CoM if the now massive photon imparts motion and apparent thrust in the small end direction? No.  What if I take those pumped up photons before I hit the endplate and decay them into evanescent waves which can't backscatter back into the large end which is the action that Conservation of Momentum uses.  Added: When a photon is emitted or absorbed, it transfers h bar of angular momentum and the associated energy is also transferred.

This is one reason I wanted the tuning chamber in the small end. And I like X_ray's idea of the trap and I can insert a probe into it to monitor energy conditions.


Reading two papers right now and here is one of my favorite things cropping up with the Golden Ratio....
"The universality of this phenomenon is revealed by analyzing, in detail, the cases corresponding to a) total internal reflection (TIR) b) waveguides c)optical fibers d) surface electromagnetic waves. We also show the existence of a unique criterion in TIR (”golden
ratio condition”) "  http://arxiv.org/abs/1504.06361

And the other which is kind of interesting...
http://onlyspacetime.com/QM-Foundation.pdf

I'm going to finish these up and clean up the mess I have in the shop (it wasn't me!).

I still need a Krell brain boost! To heck with those pesky monsters from the Id.

Shell
just added a thought...

I'm trying to see a mode conversion in the flat ends cavity, and associated with that a electromagnetic center of mass oscillation.
A spatial oscillation of fields energy distribuition is a scenarium of the called bloch wave oscillation wich arises in some configurations of gain/loss Spatial symmetry ( PT symmetry) plus a "linear potential" ( a gradient of contitutives properties of medium).
A oscillation of center of mass can be viewd as a oscillation of rest reference frame too, and like a foucault pendulum where occurs a rotation of oscilattion plane because of a berry phase, I'm curious if there is a berry phase causing a lorentz boost ( a space-time hyperbolic rotation).
But both, PT symmetry breaking (hamiltonian exceptional points study), and berry phases ( topological momentum space curvature effects)  has a very hard math description.
I'm not up to the task of the maths to calculate out the equations and I would leave that to others who are much better at it them me. I guess the thing would be how would I test for that effect so I could supply good data?

I've been wondering if the quartz rod I'm using through the center of the cavity to tune the plates could be used with a laser shot through the center profile of the quartz rod show any unusual stresses? Quartz is good at showing any stresses. I'd have to be sure that it was a good optical quartz and maybe silver mirror one end would help? Things to think about.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/24/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419252#msg1419252">Quote from: Mezzenile on 08/24/2015 04:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419055#msg1419055">Quote from: VAXHeadroom on 08/23/2015 10:37 PM</a>
I had a blast doing the flights and would go again in a heartbeat.  We had 30+ people on the plane for 4 flight days and nobody got sick.

...
Maybe if you constrained it to fly down a tube...but then the tube has to have all kinds of safety constraints (they're really picky about safety obviously!).  It's a hard problem, one I'd LOVE to work on!! :)

Ok, I understand that it could be really difficult to get any accurate displacement measurement in vaccuum during a parabolic flight.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419069#msg1419069">Quote from: Prunesquallor on 08/24/2015 12:42 AM</a>
If you could get the device to behave that way in parabolic flight, why could you not measure the thrust of the same device in the lab?  What effect are we eliminating by putting in in free fall?  Why not just put it on a air bearing floor?

I agree that in principle the initial thrust can be measured on a static test bench. But I would like to measure precisely how this thrust varies when the speed of the cavity increases under its action. There is a strong rationale to think that the thrust should decrease (or the RF power consumption of the cavity increase ...)  when the speed increases.

For what concern the use of a air bearing floor, I suppose that it entails to operate at ambiant pressure and that the unevitable air resistance would too much perturbate the dynamic of the experience.

In vacuum? On an airplane? No way.  That's essentially a pressure vessel, no way they'd let that on a plane - way too dangerous.  Free-flying in a vacuum requires a spaceflight.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 06:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419241#msg1419241">Quote from: SeeShells on 08/24/2015 04:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419234#msg1419234">Quote from: rfmwguy on 08/24/2015 03:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419223#msg1419223">Quote from: SeeShells on 08/24/2015 02:37 PM</a>
JBtek® HDMI / VGA Digital LCD Driver Board with 9" TFT LCD for Raspberry Pi

DEWALT DW5576 3/8-Inch Diamond Drill Bit 2 Arriving today by 8pm

compass magnetometer IC, I2C, HMC5883L, PCB module, for Arduino microcontroller
( 141332300714 )
Estimated delivery Mon, Aug 24 - Mon, Aug 31

Got the XYZ accelerometer already.

Seems like it's taking forever! I'm getting so antsy to test!

Shell
I'd love to see some pics or vids of your work in progress. C'mon, shell...jump in, the water's fine.
Ok will do. I'll get my camera back from a friend who borrowed it for wedding pics this weekend and take some for ya. News and pics at 9. ;)

Shell
Tried to call her but no answer, her husbands friend said they took off to Blackhawk Casino, Colorado on Sunday. Sigh... Want to bet they are still in bed sleeping... or not? ;)

And no my cell can't do pics.  My cell phone is so outdated, I still have a rotary dial on it.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/24/2015 07:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419286#msg1419286">Quote from: SeeShells on 08/24/2015 06:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419241#msg1419241">Quote from: SeeShells on 08/24/2015 04:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419234#msg1419234">Quote from: rfmwguy on 08/24/2015 03:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419223#msg1419223">Quote from: SeeShells on 08/24/2015 02:37 PM</a>
JBtek® HDMI / VGA Digital LCD Driver Board with 9" TFT LCD for Raspberry Pi

DEWALT DW5576 3/8-Inch Diamond Drill Bit 2 Arriving today by 8pm

compass magnetometer IC, I2C, HMC5883L, PCB module, for Arduino microcontroller
( 141332300714 )
Estimated delivery Mon, Aug 24 - Mon, Aug 31

Got the XYZ accelerometer already.

Seems like it's taking forever! I'm getting so antsy to test!

Shell
I'd love to see some pics or vids of your work in progress. C'mon, shell...jump in, the water's fine.
Ok will do. I'll get my camera back from a friend who borrowed it for wedding pics this weekend and take some for ya. News and pics at 9. ;)

Shell
Tried to call her but no answer, her husbands friend said they took off to Blackhawk Casino, Colorado on Sunday. Sigh... Want to bet they are still in bed sleeping... or not? ;)

And no my cell can't do pics.  My cell phone is so outdated, I still have a rotary dial on it.

Shell

Tracfone has some phones that can shoot video (not well) for around $20-60.  I've got a tablet, GPS unit, cheap smartphone and camera all about to fail at around the same time.  Thinking about maybe just picking up the new iPhone on a payment plan when it comes out and and using it with a cheap tracfone subscription  The phone functions are almost ancillary to the other uses I want to get out of the thing.

That said, most digital cameras can shoot video now.  Here's a link to a $50 one that is Amazon prime eligible http://www.amazon.com/A1035-RD-DIGITAL-OPTICAL-ADVANCED-FEATURES/dp/B001WYNZ3C/ref=sr_1_31?s=photo&ie=UTF8&qid=1440444535&sr=1-31&keywords=digital+camera&refinements=p_36%3A1253504011%2Cp_85%3A2470955011 (http://www.amazon.com/A1035-RD-DIGITAL-OPTICAL-ADVANCED-FEATURES/dp/B001WYNZ3C/ref=sr_1_31?s=photo&ie=UTF8&qid=1440444535&sr=1-31&keywords=digital+camera&refinements=p_36%3A1253504011%2Cp_85%3A2470955011)  and a refurbished camera that is also prime eligible http://www.amazon.com/Fujifilm-JX665-Digital-Camera-Refurbished/dp/B00R4WZ0OS/ref=sr_1_5?s=photo&ie=UTF8&qid=1440444883&sr=1-5&keywords=digital+camera&refinements=p_36%3A1253504011%2Cp_85%3A2470955011 (http://www.amazon.com/Fujifilm-JX665-Digital-Camera-Refurbished/dp/B00R4WZ0OS/ref=sr_1_5?s=photo&ie=UTF8&qid=1440444883&sr=1-5&keywords=digital+camera&refinements=p_36%3A1253504011%2Cp_85%3A2470955011).  If you have a situation where the camera might not survive, something cheap and disposable might come in handy.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/24/2015 07:55 PM

Paul Kocyla (@movax on Hackaday.io) just assembled the new Silver baby-EmDrive cavity today and has some questions:

New Cavity Assembled (https://hackaday.io/project/5596-em-drive/log/23996-new-cavity-assembled)
Quote from: Paul Kocyla
Got the endplate piston from Jo today. Here´s the assembled cavity.
I got a question for the microwave professionals: There is a small gap between the endplate piston and the cavity walls. What will this mean for the wave propagation?
The piston might touch the cavity on one side. Should I better isolate the cavity wall from the piston, or should it somehow contact the cavity on all sides?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/24/2015 07:57 PM
For @TheTraveller  8) *

https://www.reddit.com/r/EmDrive/comments/3i0pzm/thetravelleremd_rage_quit/cue8qvf

Such a great song.

* Also anyone who likes to groove.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/24/2015 07:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419304#msg1419304">Quote from: flux_capacitor on 08/24/2015 07:55 PM</a>
Paul Kocyla (@movax on Hackaday.io) just assembled the new Silver baby-EmDrive cavity today and has some questions:

New Cavity Assembled (https://hackaday.io/project/5596-em-drive/log/23996-new-cavity-assembled)
Quote from: Paul Kocyla
Got the endplate piston from Jo today. Here´s the assembled cavity.
I got a question for the microwave professionals: There is a small gap between the endplate piston and the cavity walls. What will this mean for the wave propagation?
The piston might touch the cavity on one side. Should I better isolate the cavity wall from the piston, or should it somehow contact the cavity on all sides?
The question is which mode he like to drive.
There are big differences between the fields and currents through the gap for different mode shapes!
Was already discussed here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418696#msg1418696
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418939#msg1418939

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 08:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419254#msg1419254">Quote from: BL on 08/24/2015 04:31 PM</a>
Re rfmwguy Post #991

If you are still looking for HV wire, McMaster-Carr has plenty:

http://www.mcmaster.com/#high-voltage-wire/=ymwsh6

It starts at 10 KV rating, goes up to 42 KV, and is available in pieces as short as 5' @ under $2/ft for the lower voltage/smaller conductor stuff.  At 4 KV, I wouldn't expect you would need a very large conductor to handle the magnetron current.
Very cool, thanks...might use this down the road if I continue the project.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 08:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419249#msg1419249">Quote from: X_RaY on 08/24/2015 04:24 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
NSF-1701 on fulcrum ready to flight test: https://youtu.be/XQ5HOYeJf4Y
Looks very nice :)
Do you have an idea how the current resonance frequency of your target mode is with the spherical copper mesh? (How much lower compared with the flat as calculated before?)
I can only guess about 5% lower resonance, or about 2.2 to 2.3 GHz

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 08:27 PM
With my compliments, have attached a pdf laser target pdf sheet I'll print up using shell's bar graph idea.

Builders are feel free to use it...open source is my motto  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 08:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419304#msg1419304">Quote from: flux_capacitor on 08/24/2015 07:55 PM</a>
Paul Kocyla (@movax on Hackaday.io) just assembled the new Silver baby-EmDrive cavity today and has some questions:

New Cavity Assembled (https://hackaday.io/project/5596-em-drive/log/23996-new-cavity-assembled)
Quote from: Paul Kocyla
Got the endplate piston from Jo today. Here´s the assembled cavity.
I got a question for the microwave professionals: There is a small gap between the endplate piston and the cavity walls. What will this mean for the wave propagation?
The piston might touch the cavity on one side. Should I better isolate the cavity wall from the piston, or should it somehow contact the cavity on all sides?
Contact, no gaps especially @ 25 GHz is my 2 cents.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/24/2015 08:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419306#msg1419306">Quote from: X_RaY on 08/24/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419304#msg1419304">Quote from: flux_capacitor on 08/24/2015 07:55 PM</a>
Paul Kocyla (@movax on Hackaday.io) just assembled the new Silver baby-EmDrive cavity today and has some questions:

New Cavity Assembled (https://hackaday.io/project/5596-em-drive/log/23996-new-cavity-assembled)
Quote from: Paul Kocyla
Got the endplate piston from Jo today. Here´s the assembled cavity.
I got a question for the microwave professionals: There is a small gap between the endplate piston and the cavity walls. What will this mean for the wave propagation?
The piston might touch the cavity on one side. Should I better isolate the cavity wall from the piston, or should it somehow contact the cavity on all sides?
The question is which mode he like to drive.
There are big differences between the fields and currents through the gap for different mode shapes!
Was already discussed here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418696#msg1418696
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418939#msg1418939

I know, that's why I asked him which mode he wants to excite, but he doesn't know. He specifically answered (https://hackaday.io/project/5596-em-drive/log/23696-silver-cavity-arrived/discussion-33428) last weeek:

Quote from: Paul Kocyla
We want to permutate all possible parameters of the EMdrive, which means many positions of the small endplate and a wide frequency spectrum 23-25 GHz. The tests will be run automatically. So there is no specific mode planned

But at such a small size, several modes could overlap near the same frequency, for example TE013, TE114 and TM113.

BTW his antenna is a 1/4 lambda stub of 24 GHz, located near the small end.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/24/2015 08:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418832#msg1418832">Quote from: flux_capacitor on 08/22/2015 10:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418798#msg1418798">Quote from: rfmwguy on 08/22/2015 08:21 PM</a>
There was a coupling loop on an EW pic behind the HDPE. It was abt 3.5 cm from edge, which is where mine is.

If you mean this internal picture, the loop was near the 280 mm big base:

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057032,3Bimage.pagespeed.ic.AwGtB_pjPB.jpg)

I have gone over and checked all the data posted at NSF by Paul March and I fully agree: the NASA Eagleworks copper truncated cone has an antenna mounted on the frustum sidewall approximately 15% of the frustum’s 9.00” length, (~1.35” or 3.43cm), up from the Big Base of the cavity as shown in the image in your post and as shown in their AIAA Brady et.al report.

This is very crucial because NASA's test (which in my opinion are the most trustworthy tests) have been run with the antenna near the Big End.

Thus NASA's tests are in agreement with the Meep computer runs, post-processed with Wolfram Mathematica ( http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516 ) to analyze the stress tensor and forces that show that it is only when the antenna is located near the Big End that the there is an imbalance of forces pointing towards the small end that cannot be overcome by the reactions from the forces on the side-walls.   When the antenna is placed near the small end, the forces from the side wall can overcome the force towards the big end and result in no net force on the truncated cone.

I look forward to RFMWGUY's test with the magnetron at the small end to see what he finds :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/24/2015 08:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419315#msg1419315">Quote from: flux_capacitor on 08/24/2015 08:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419306#msg1419306">Quote from: X_RaY on 08/24/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419304#msg1419304">Quote from: flux_capacitor on 08/24/2015 07:55 PM</a>
Paul Kocyla (@movax on Hackaday.io) just assembled the new Silver baby-EmDrive cavity today and has some questions:

New Cavity Assembled (https://hackaday.io/project/5596-em-drive/log/23996-new-cavity-assembled)
Quote from: Paul Kocyla
Got the endplate piston from Jo today. Here´s the assembled cavity.
I got a question for the microwave professionals: There is a small gap between the endplate piston and the cavity walls. What will this mean for the wave propagation?
The piston might touch the cavity on one side. Should I better isolate the cavity wall from the piston, or should it somehow contact the cavity on all sides?
The question is which mode he like to drive.
There are big differences between the fields and currents through the gap for different mode shapes!
Was already discussed here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418675#msg1418675
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418696#msg1418696
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418939#msg1418939

I know, that's why I asked him which mode he wants to excite, but he doesn't know. He specifically answered (https://hackaday.io/project/5596-em-drive/log/23696-silver-cavity-arrived/discussion-33428) last weeek:

Quote from: Paul Kocyla
We want to permutate all possible parameters of the EMdrive, which means many positions of the small endplate and a wide frequency spectrum 23-25 GHz. The tests will be run automatically. So there is no specific mode planned

But at such a small size, several modes could overlap near the same frequency, for example TE013, TE114 and TM113.

BTW his antenna is a 1/4 lambda stub of 24 GHz, located near the small end.
I work in the K-band (18–26,5 GHz) with conical cavities some years till now! With a silver plated cavity the resonance bandwidth is to small for overlapping more than 2..3 modes and even this is only random or a tuning problem!
(VNA backed!)
Tell him the can contact me in germany if he like to do so. (first time via PM here)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/24/2015 09:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419318#msg1419318">Quote from: X_RaY on 08/24/2015 08:41 PM</a>
Tell him the can contact me in germany if he like to do so. (first time via PM here)
Thanks for him! Paul will contact you soon :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 08/24/2015 09:43 PM
Anyone else keep having great ideas and insight (mostly while daydreaming and dreaming) only to forget what it was? I dream of photons and copper cans every night.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/24/2015 10:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419328#msg1419328">Quote from: Mulletron on 08/24/2015 09:43 PM</a>
Anyone else keep having great ideas and insight (mostly while daydreaming and dreaming) only to forget what it was? I dream of photons and copper cans every night.
This is very common: I have books by famous scientists like Poincare, Duhem and others, as well as articles written by mathematician's, physicists, and inventors that some of the best ideas (their aha!) moments often come during dreams.  Many of them kept a notebook by their bed to write down their ideas as soon as awake, in order not to forget them.  Our unconscious mind keeps thinking about problems while we are asleep.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/24/2015 10:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419284#msg1419284">Quote from: VAXHeadroom on 08/24/2015 06:10 PM</a>
In vacuum? On an airplane? No way.  That's essentially a pressure vessel, no way they'd let that on a plane - way too dangerous.  Free-flying in a vacuum requires a spaceflight.

The NASA drop tube that I have indicated operates in vacuum condition.

For the plane and its parabolic trajectory I have suggested the use of a small vacuum chamber around the test device (I agree... nothing afraid me :) ). But I understand that even if the plane can flight with this test set up, it is impossible to insure that the test device will not hurt the walls of the vacuum chamber. So we forget this idea ...

Remains the possibility of a test within the vacuum drop tube. Now, are 5.3 seconds of free fall time sufficient to measure a thrust variation ? This is an open question.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rq3 on 08/24/2015 10:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419087#msg1419087">Quote from: rfmwguy on 08/24/2015 03:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419085#msg1419085">Quote from: WarpTech on 08/24/2015 03:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419077#msg1419077">Quote from: SeeShells on 08/24/2015 01:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419071#msg1419071">Quote from: SteveD on 08/24/2015 12:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419054#msg1419054">Quote from: rfmwguy on 08/23/2015 10:33 PM</a>
(video snip)

Can you set up a second camera watching the frustum and rig while the first looks at the paper?  Not perfect, but the first thing I'd think of with the camera only recording the laser moving is that you might be physically manipulating the rig.  Given that the lights are going to be off, I realize that this would be difficult.  Maybe some form of thermal camera?  Then again I can understand just wanting the verify that the thing is giving some kind of detectable result before fiddling with it more.

I have a suggestion that might Kill three birds with one stone rfmwguy.

Take your camera and shoot the backside of the graph paper. Easier for your camera to see the red dot without blossoming out from sensitivity to the red light.

You can see the device and the paper in one view if it's set up right.

On the front of the paper run two strips of electrical tape up and down separated by a small gap maybe 1/4 inch. It will help define the movement. Like a vertical bar graph display and make your lines heavy horizontally when you do the graph paper.

One other thing, twist the power leads together and the heater leads together, you'll reduce noise and cancel AC effects the leads may carry.

I also suggested twisting the leads, but I'm not sure the insulation on the red wire is actually 4000V rated. If not, don't do it, it may breakdown through to the other wires. I'm not sure that terminal block is good for 4000V either. Humidity may cause it to arc to ground.
Todd
Have to confess, I did a test firing this AM. No arcs on terminal. Humidity was low. Will measure that on Tuesday. Yes, I'm avoiding anything next to hv insulation. Proper wire for this is silicone insulated...like on oscilloscope test lead, only heavier guage. Could not locate easily.

Spark plug wire from your local auto parts store. You can even get it shielded.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/24/2015 11:02 PM
Brain is locked into loop...
I keep thinking about building the best way to have "clean" resonance patterns by using a one way material, that is "transparent" to microwaves from one side and not from the other.

It would allow the wave guides to be placed at the big or small end (needs to be tested?) and result in very clean internal patterns, even odd shaped ones like trumpet/horn shaped ones.

Technical/scientific English is often  an obstacle for me, but i did manage to find a few potential interesting articles. Comprehending what's written, that's another turf...

anyway...the magical words seem to be : nonreciprocal meta-materials. I just cant picture any real material, or find where you - potentially - could buy it....

http://journals.aps.org/prb/abstract/10.1103/PhysRevB.85.205101

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6565764&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel7%2F6558537%2F6565651%2F06565764.pdf%3Farnumber%3D6565764

http://people.ee.duke.edu/~cummer/ElectromagneticMetamaterials.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/24/2015 11:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419338#msg1419338">Quote from: Mezzenile on 08/24/2015 10:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419284#msg1419284">Quote from: VAXHeadroom on 08/24/2015 06:10 PM</a>
In vacuum? On an airplane? No way.  That's essentially a pressure vessel, no way they'd let that on a plane - way too dangerous.  Free-flying in a vacuum requires a spaceflight.

The NASA drop tube that I have indicated operates in vacuum condition.

For the plane and its parabolic trajectory I have suggested the use of a small vacuum chamber around the test device (I agree... nothing afraid me :) ). But I understand that even if the plane can flight with this test set up, it is impossible to insure that the test device will not hurt the walls of the vacuum chamber. So we forget this idea ...

Remains the possibility of a test within the vacuum drop tube. Now, are 5.3 seconds of free fall time sufficient to measure a thrust variation ? This is an open question.

Hadn't thought about a drop tube.  That's a really interesting idea.  If you could build a device with a few mm/s2 accel I'm sure you could detect that reliably! 

http://www.nasa.gov/audience/foreducators/k-4/features/F_Drop_Everything.html

Not vacuum though :(

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/24/2015 11:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419317#msg1419317">Quote from: Rodal on 08/24/2015 08:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418832#msg1418832">Quote from: flux_capacitor on 08/22/2015 10:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418798#msg1418798">Quote from: rfmwguy on 08/22/2015 08:21 PM</a>
There was a coupling loop on an EW pic behind the HDPE. It was abt 3.5 cm from edge, which is where mine is.

If you mean this internal picture, the loop was near the 280 mm big base:

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1057032,3Bimage.pagespeed.ic.AwGtB_pjPB.jpg)

I have gone over and checked all the data posted at NSF by Paul March and I fully agree: the NASA Eagleworks copper truncated cone has an antenna mounted on the frustum sidewall approximately 15% of the frustum’s 9.00” length, (~1.35” or 3.43cm), up from the Big Base of the cavity as shown in the image in your post and as shown in their AIAA Brady et.al report.

This is very crucial because NASA's test (which in my opinion are the most trustworthy tests) have been run with the antenna near the Big End.

Thus NASA's tests are in agreement with the Meep computer runs, post-processed with Wolfram Mathematica ( http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516 ) to analyze the stress tensor and forces that show that it is only when the antenna is located near the Big End that the there is an imbalance of forces pointing towards the small end that cannot be overcome by the reactions from the forces on the side-walls.   When the antenna is placed near the small end, the forces from the side wall can overcome the force towards the big end and result in no net force on the truncated cone.

I look forward to RFMWGUY's test with the magnetron at the small end to see what he finds :)
Doc, can yuo give me the url of  paul march's folder again? Thanks...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/24/2015 11:32 PM
aero and Dr. Rodel. These are the dims you need to use. Let me know if it's an issue.

Shell

Mod the image.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/25/2015 12:24 AM
Doc, nevermind. I found the original EW pic showing the drive antenna on the small end.

This is where I suspect Mr. March was going. Also he had a top-mounted 100 kW Magnetron on a concept drawing.

Its a year after your other pic.

Correction, the drive antenna was in front of the dielectric. Strange looking HDPE, almost looks infused with graphene  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 12:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419366#msg1419366">Quote from: rfmwguy on 08/25/2015 12:24 AM</a>
Doc, nevermind. I found the original EW pic showing the drive antenna on the small end.

This is where I suspect Mr. March was going. Also he had a top-mounted 100 kW Magnetron on a concept drawing.

Its a year after your other pic.

Correction, the drive antenna was in front of the dielectric. Strange looking HDPE, almost looks infused with graphene  ;)

I had forgotten about that design.  If my memory serves me correctly, he wrote that they got bad thrust results with that design.

At the time of the discussion we were not running Meep and hence the issue of the antenna location did not come up.

Perhaps the reason why they got bad results has everything to do with the fact that the antenna was at the small end :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/25/2015 01:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419338#msg1419338">Quote from: Mezzenile on 08/24/2015 10:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419284#msg1419284">Quote from: VAXHeadroom on 08/24/2015 06:10 PM</a>
In vacuum? On an airplane? No way.  That's essentially a pressure vessel, no way they'd let that on a plane - way too dangerous.  Free-flying in a vacuum requires a spaceflight.

The NASA drop tube that I have indicated operates in vacuum condition.

For the plane and its parabolic trajectory I have suggested the use of a small vacuum chamber around the test device (I agree... nothing afraid me :) ). But I understand that even if the plane can flight with this test set up, it is impossible to insure that the test device will not hurt the walls of the vacuum chamber. So we forget this idea ...

Remains the possibility of a test within the vacuum drop tube. Now, are 5.3 seconds of free fall time sufficient to measure a thrust variation ? This is an open question.

It's not so much the drop that worries me as the effect on the device of the stop at the end. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/25/2015 01:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419370#msg1419370">Quote from: Rodal on 08/25/2015 12:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419366#msg1419366">Quote from: rfmwguy on 08/25/2015 12:24 AM</a>
Doc, nevermind. I found the original EW pic showing the drive antenna on the small end.

This is where I suspect Mr. March was going. Also he had a top-mounted 100 kW Magnetron on a concept drawing.

Its a year after your other pic.

Correction, the drive antenna was in front of the dielectric. Strange looking HDPE, almost looks infused with graphene  ;)

I had forgotten about that design.  If my memory serves me correctly, he wrote that they got bad thrust results with that design.

At the time of the discussion we were not running Meep and hence the issue of the antenna location did not come up.

Perhaps the reason why they got bad results has everything to do with the fact that the antenna was at the small end :)
Could not locate docs on performance related to this specific version. It just seemed it was later than shawyers loop design and only one I could confirm had a dielectric.

(Edit) also note the correct way to measure Q ...2 port.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/25/2015 02:26 AM
A couple of models using SeeShell's (and Rodal's) dimensions posted earlier.

Dimensions in both cases are:

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

These dimensions on the model with spherical ends are exactly the same. The dimensions of the spherical ends are:

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

These spherical segments match exactly to the conic section. Note that the axial length is the axial length of the conic section and is not the difference in the radial distance between the two spherical sections. That distance is r2 - r1 = 0.370852 m - 0.20114 m. In the meep model shown, r2 is the inside radius of the big end spherical section while r1 is the outside radius of the small end spherical section.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/25/2015 02:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419284#msg1419284">Quote from: VAXHeadroom on 08/24/2015 06:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419252#msg1419252">Quote from: Mezzenile on 08/24/2015 04:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419055#msg1419055">Quote from: VAXHeadroom on 08/23/2015 10:37 PM</a>
I had a blast doing the flights and would go again in a heartbeat.  We had 30+ people on the plane for 4 flight days and nobody got sick.

...
Maybe if you constrained it to fly down a tube...but then the tube has to have all kinds of safety constraints (they're really picky about safety obviously!).  It's a hard problem, one I'd LOVE to work on!! :)

Ok, I understand that it could be really difficult to get any accurate displacement measurement in vaccuum during a parabolic flight.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419069#msg1419069">Quote from: Prunesquallor on 08/24/2015 12:42 AM</a>
If you could get the device to behave that way in parabolic flight, why could you not measure the thrust of the same device in the lab?  What effect are we eliminating by putting in in free fall?  Why not just put it on a air bearing floor?

I agree that in principle the initial thrust can be measured on a static test bench. But I would like to measure precisely how this thrust varies when the speed of the cavity increases under its action. There is a strong rationale to think that the thrust should decrease (or the RF power consumption of the cavity increase ...)  when the speed increases.

For what concern the use of a air bearing floor, I suppose that it entails to operate at ambiant pressure and that the unevitable air resistance would too much perturbate the dynamic of the experience.

In vacuum? On an airplane? No way.  That's essentially a pressure vessel, no way they'd let that on a plane - way too dangerous.  Free-flying in a vacuum requires a spaceflight.

I used to do some Vomit Comet runs. They would allow G-bottles of pressurized air onboard. Don't know if that's substantially different safety-wise as a small vac chamber. The bigger problem may be the roughing pumps etc. 

Just to make your day, one of the most bizarre experiments that was onboard one of my flights was a live, but anesthasized pig. The ISS crews were learning how to cauterize and suture injuries in zero-g including bleeding etc.  if there's anything that tops off the feeling of nausea after 30-40 parabolas, it's the smell of burning pork.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/25/2015 03:01 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419348#msg1419348">Quote from: Flyby on 08/24/2015 11:02 PM</a>
Brain is locked into loop...
I keep thinking about building the best way to have "clean" resonance patterns by using a one way material, that is "transparent" to microwaves from one side and not from the other.

It would allow the wave guides to be placed at the big or small end (needs to be tested?) and result in very clean internal patterns, even odd shaped ones like trumpet/horn shaped ones.

Technical/scientific English is often  an obstacle for me, but i did manage to find a few potential interesting articles. Comprehending what's written, that's another turf...

anyway...the magical words seem to be : nonreciprocal meta-materials. I just cant picture any real material, or find where you - potentially - could buy it....

http://journals.aps.org/prb/abstract/10.1103/PhysRevB.85.205101

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6565764&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel7%2F6558537%2F6565651%2F06565764.pdf%3Farnumber%3D6565764

http://people.ee.duke.edu/~cummer/ElectromagneticMetamaterials.html

Metamaterials aren't really a "material" like copper or aluminum.  They are, instead, special arrangements of antennas, small resonators, conductors, and dielectrics.  Combining these in clever ways can create optical properties that exist nowhere in nature.  In the Phys. Rev. B abstract you linked the yellow PCB (picture C) is the metamaterial.  Picture D is an array of them ready to be slid into a waveguide.  These are an active exciting area of research, and time spent learning about them certainly won't be wasted. *

*Example: There are "off-the-shelf" split ring resonator and post designs for materials that exhibit negative radiation pressure.  These seem _very relevant_ to emdrive research!

There are other ways to isolate a resonator.  The latest Yang design used a ferrite Iris and tuning screws to minimize reflected energy back to the magnetron.  His prior design used a Microwave Circulator, like a one-way traffic roundabout, to isolate the resonator.  Any energy that reflected out of the resonator was passed into a microwave absorber and the energy radiated as heat.


On a related note, BN.com has a couple of <$15 copies of Guru's Electromagnetic Field Theory Fundamentals.  I'm working through it now, and am making progress with (despite?) self-taught calculus.

One more plug: Walter Lewin, formerly of MIT, has posted his Physics courses and coursework on youtube.  His channel is here:

https://www.youtube.com/channel/UCiEHVhv0SBMpP75JbzJShqw (https://www.youtube.com/channel/UCiEHVhv0SBMpP75JbzJShqw)

Does that help?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 03:34 AM
Apologises for the blackout.

Seems I picked up a super bug during my 2 stays in hospital. So back again where I got the infection. NOT happy about that! Was told it is a low level infection and is curable. I getting a bit concerned that this whole prostate cancer exercise is going from one op and you are done to not looking good. Until my op, last time I was in a hospital was when I was 14 and broke my elbow joint. I'm late 60's, use no meds, pressure, heart rate, cholesterol, etc in middle to low side range for a 40 year old. Don't eat junk food. All fresh and naturally grown fruit and veggies. Lots of Salmon. Do enjoy a glass or 2 of a nice Aussie Shiraz. So this whole hospital experience has really opened up my eyes. These guys just guess at what to do next........................

Had a bad reaction to the 1st round of anti superbug drugs. Had me tripping out. Not good to have a mobile phone when tripping out. Have restored my Google Drive public access. Did delete a few posts here and on Reddit until the nurse took my phone away for a few days.

Have no idea when I will get back home.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/25/2015 03:53 AM
Well, the good news is you're back. The bad news is that all those conspiracy theories we hatched up are bunkum  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Econocritic on 08/25/2015 04:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419380#msg1419380">Quote from: rfmwguy on 08/25/2015 01:58 AM</a>

Could not locate docs on performance related to this specific version. It just seemed it was later than shawyers loop design and only one I could confirm had a dielectric.

(Edit) also note the correct way to measure Q ...2 port.

This seems like a good place for Paul March's full post  where the referenced image was attached. 

I probably speak for many silent readers when I say: This has been the best ongoing discussion I have ever followed on the internet.  I am incredibly excited for rfmwguy's upcoming experiments and seeing pictures of Sea Shells' setup and future tests.  Thank you everyone for trying to figure this thing out.

http://forum.nasaspaceflight.com/index.php?topic=36313.1100
Quote
Dr. Rodal & Crew:

The Eagleworks team has already build a 6061 aluminum frustum cavity with 1/4" thick walls and O-ring end caps meant to hold a 1 Bar pressure differential with internal nickel/copper/silver/gold plating system on all interior surfaces with plating thickness of 10-to-15 microns for the first three layers and 0.5 microns for exposed to the RF gold layer.  Sadly the gold layer was just as thick as the rest of the plated layers and textured as well, so as far as the applied ~2.0 GHz RF was concerned it was only interacting with the rough gold layer.  This had the effect of cutting the resonant Q-factor for this aluminum frustum by almost a factor of three over our copper frustum for the resonances of interest. 

At the same time we also tried using a smaller volume, higher-K (e-r=~40) ceramic dielectric resonator discs in the Al cavity mounted at its small OD end, while driving it at its TE011 mode if memory serves.  Bottom line was that this configuration was a total bust in regards to thrust production in our torque pendulum system running at this resonant mode.  This aluminum frustum design also turned out to be ~4X times the mass of the thin walled copper cavity even while using lower density aluminum for its construction.  This exercise was a tribute to the fact that one should never ASSUME that you know what you are doing until proven otherwise!  And oh yes, and only try one variation in the design at a time or one will get lost, fast!

Best, Paul M.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/25/2015 04:09 AM
Great you're back TT. I hope you get well soon.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 05:57 AM

This is why I think the meep looks a little off. we need to place within the modes not 1/4 wave.

Long day today and longer tomorrow... nite all

Glad the aliens didn't abduct you TT and use probes on you... no wait, you were in the hospital... they did.

Shell

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037

<quote from Dr. Rodal>
The wave-pattern wavelengths for TE012 = 2.45008 GHz for these dimensions:

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

has a first absolute value maximum, for the wave-pattern next to the small base that occurs at:

28.1465% of the distance between the bases, measuring from the small base

which for  axial length=0.163 m

0.0458789 m axial distance from the small base

this is where I think the antenna should be located when locating the antenna near the small base

____________________________________________________________________________________

the next absolute value maximum, for the wave-pattern next to the big base occurs at:

77.3927% of the distance between the bases, measuring from the small base

or equivalently

22.6073% of the distance between the bases, measuring from the big base

which for  axial length=0.163 m means

0.12615 m axial distance from the small base , or equivalently

0.0368499 m axial distance from the big base

this is where I think the antenna should be located when locating the antenna near the big base

____________________________________________________________________________________

Thus, optimal locations are NOT at 1/4 of the axial distance, rather the optimal location near the small base is further away, at 28.1465% of the distance from the small base, while the optimal location near the big base is closer to the big base, at 22.6073% of the distance from the small base


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419385#msg1419385">Quote from: aero on 08/25/2015 02:26 AM</a>
A couple of models using SeeShell's (and Rodal's) dimensions posted earlier.

Dimensions in both cases are:

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

These dimensions on the model with spherical ends are exactly the same. The dimensions of the spherical ends are:

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

These spherical segments match exactly to the conic section. Note that the axial length is the axial length of the conic section and is not the difference in the radial distance between the two spherical sections. That distance is r2 - r1 = 0.370852 m - 0.20114 m. In the meep model shown, r2 is the inside radius of the big end spherical section while r1 is the outside radius of the small end spherical section.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 06:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419412#msg1419412">Quote from: SeeShells on 08/25/2015 05:57 AM</a>
...

Suspect the reason Shawyer suggested to me to use TE013 is because excitation should happen to the middle lobe and because it is then equal guide wavelength from each end.

If you check his latest patent and publications, excitation, Rf feed occurs approx in the middle or where the centre of the middle lobe of TE013 occurs.

I also note Prof Yangs latest 117.5k Q cavity was excited by a narrow band Rf signal, while using a 2 section wave guide arrangement to feed the resultant Rf into the middle of the cavity.

Seems both Shawyer and Prof Yang are going for high Q cavities, middle fed via tuned and impedance matched waveguide systems and narrow band Rf. This may suggest using an antenna to excited and continue to fill the cavity with Rf energy may have a bad antenna coupling factor that destroys operational Q and thus Force generation.

Match that with Roger telling me to use TE013, his latest middle lobe feed is good & the breadcrumb trail now makes sense.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/25/2015 07:01 AM

@TheTraveller. I asked this while I think you were away. Meaning if computer modeling is not currently forecasting accurate thrust predictions. Should there be other things to start looking at/recording/monitoring, for EM Drive builders? So that better computer models can be used to also use that input data with factors contributing to thrust besides using only the current factors they are using now. If it comes to that?  Do you have any suggestions?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418562#msg1418562">Quote from: TheUberOverLord on 08/21/2015 07:41 PM</a>
@Dr. Rodal and others

In reference to Dr. Rodal's post here:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516

Is it possible that at this stage of actual EM Drive builds and their resulting test data ("In the public domain"). That computer based modeling might not yet include all required factors as input data to produce accurate estimates in their output data? Of all classical physics theories which could be involved, prove outside classical theories are involved or even if there are combinations of both currently taking place.

If somehow this becomes more apparent ("In the soon to be near future") that current computer modeling can't currently accurately account for the total results when those specifications are used for actual EM Drive builds. Then what's next?

Should things like internal photography and video inside cavities be used, magnetic fields and other recording and sensing devices be used in the future, during the testing of EM Drive builds?

I would like to hear what others suggested plan B's are out there to be considered if and when current computer models fail miserably to make accurate estimates. I would think others would as well.

Would you mostly all have similar plan B suggestions?

Especially with new EM Drive builds about to prove or disprove the accuracy of current computer models being used as being reasonably solid or in need of some major "Code changes" that might not even have the required mathematical formulas yet to be able to implement those "Code changes".

Don

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/25/2015 07:08 AM
Can't wait for rmfguys run tomorrow!!  Having waited this long I can't wait for the test runs to start!!  :D

While there seems to be a consensus forming on having the feed near the big end, it is not unreasonable to expect measurable results from rmfguys experiment simply because we have a reasonably well coupled 700W magnetron hooked up.

As the old saying goes "Quantity has a quality all of its own".

It will be interesting to see if brute force will work.  This experiment is a kind of sensitivity analysis.  If 700W pumping in does not do something then we are looking at very tight tolerances indeed - something that TT (welcome back!) and Shell are gearing up for.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 07:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419429#msg1419429">Quote from: TheUberOverLord on 08/25/2015 07:01 AM</a>
@TheTraveller. I asked this while I think you were away. Do you have any suggestions?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418562#msg1418562">Quote from: TheUberOverLord on 08/21/2015 07:41 PM</a>
@Dr. Rodal and others

In reference to Dr. Rodal's post here:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516

Is it possible that at this stage of actual EM Drive builds and their resulting test data ("In the public domain"). That computer based modeling might not yet include all required factors as input data to produce accurate estimates in their output data? Of all classical physics theories which could be involved, prove outside classical theories are involved or even if there are combinations of both currently taking place.

If somehow this becomes more apparent ("In the soon to be near future") that current computer modeling can't currently accurately account for the total results when those specifications are used for actual EM Drive builds. Then what's next?

Should things like internal photography and video inside cavities be used, magnetic fields and other recording and sensing devices be used in the future, during the testing of EM Drive builds?

I would like to hear what others suggested plan B's are out there to be considered if and when current computer models fail miserably to make accurate estimates. I would think others would as well.

Would you mostly all have similar plan B suggestions?

Especially with new EM Drive builds about to prove or disprove the accuracy of current computer models being used as being reasonably solid or in need of some major "Code changes" that might not even have the required mathematical formulas yet to be able to implement those "Code changes".

Don

Don

My computer model is based on advise from Shawyer.

It can search for resonance in 16 different modes and predicts Force generation from inputted cavity Q and power, assuming an Rf feed coupling factor of 1. It will shortly predict cavity Q, from inputted wall material choice and operational temperature.

It will also shortly suggests where the internal nodes & lobes for the chosen resonant modes are located along the frustum side wall.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 07:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419431#msg1419431">Quote from: demofsky on 08/25/2015 07:08 AM</a>
  If 700W pumping in does not do something then we are looking at very tight tolerances indeed - something that TT (welcome back!) and Shell are gearing up for.

If there is no significant resonance in a useful mode or if the antenna coupling factor is bad, then all that will happen is stuff will get warm.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/25/2015 07:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419225#msg1419225">Quote from: rfmwguy on 08/24/2015 02:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419215#msg1419215">Quote from: deltaMass on 08/24/2015 01:57 PM</a>
Good stuff. I reckon your chief artifactual source is going to be convective thermal in nature. It's tough to provide an estimate of its magnitude.
Yes, there is a 12 in square copper board directly above the magnetron, where heat will rise around it. This is about the only variable to contend with as I've tried to use non magnetic materials on the fulcrum. Any downward force will be working agains this lift. So if I see anything, I'll invert the engine, measure upwards force then subtract the difference. This should approximate thermal lift.

If you choose to later mount the magnetron on the side of the fustrum like Ilian then this might mitigate some of the convection.  (I am assuming a side mount would require supports since the mesh won't be able to directly support the magnetron.)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/25/2015 07:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419432#msg1419432">Quote from: TheTraveller on 08/25/2015 07:13 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419429#msg1419429">Quote from: TheUberOverLord on 08/25/2015 07:01 AM</a>
@TheTraveller. I asked this while I think you were away. Do you have any suggestions?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418562#msg1418562">Quote from: TheUberOverLord on 08/21/2015 07:41 PM</a>
@Dr. Rodal and others

In reference to Dr. Rodal's post here:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516

Is it possible that at this stage of actual EM Drive builds and their resulting test data ("In the public domain"). That computer based modeling might not yet include all required factors as input data to produce accurate estimates in their output data? Of all classical physics theories which could be involved, prove outside classical theories are involved or even if there are combinations of both currently taking place.

If somehow this becomes more apparent ("In the soon to be near future") that current computer modeling can't currently accurately account for the total results when those specifications are used for actual EM Drive builds. Then what's next?

Should things like internal photography and video inside cavities be used, magnetic fields and other recording and sensing devices be used in the future, during the testing of EM Drive builds?

I would like to hear what others suggested plan B's are out there to be considered if and when current computer models fail miserably to make accurate estimates. I would think others would as well.

Would you mostly all have similar plan B suggestions?

Especially with new EM Drive builds about to prove or disprove the accuracy of current computer models being used as being reasonably solid or in need of some major "Code changes" that might not even have the required mathematical formulas yet to be able to implement those "Code changes".

Don

Don

My computer model is based on advise from Shawyer.

It can search for resonance in 16 different modes and predicts Force generation from inputted cavity Q and power, assuming an Rf feed coupling factor of 1. It will shortly predict cavity Q, from inputted wall material choice and operational temperature.

It will also shortly suggests where the internal nodes & lobes for the chosen resonant modes are located along the frustum side wall.

Yes. I understand that. Also, this is not about any specific computer model currently not accurately predicting thrust, including yours.

It's now getting to the point that many EM Drive builders who use any computer models to help them build their EM Drives that had projected thrust levels will be verifying if those projected thrust levels are correct.

If they turn out to not even be close. I don't mean failures, I mean plain wrong about what the thrust turns out to be. What if any suggestions do you have for measuring/monitoring/recording additional things during EM Drive testing.

Nobody is hoping this will happen, including me. But it's a possibility that seems to have little attention given to this subject matter.

Don 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/25/2015 07:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419434#msg1419434">Quote from: TheTraveller on 08/25/2015 07:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419431#msg1419431">Quote from: demofsky on 08/25/2015 07:08 AM</a>
  If 700W pumping in does not do something then we are looking at very tight tolerances indeed - something that TT (welcome back!) and Shell are gearing up for.

If there is no significant resonance in a useful mode or if the antenna coupling factor is bad, then all that will happen is stuff will get warm.

Agreed.  That said, I can't remember rmfguys planning on this but I seem to recall he was aiming for a specific mode.  I am making (the brave?) assumption that the thermal testing and tweaking that rmfguy did earlier means that there is reasonable coupling. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: arc on 08/25/2015 07:45 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419429#msg1419429">Quote from: TheUberOverLord on 08/25/2015 07:01 AM</a>
@TheTraveller. I asked this while I think you were away. Meaning if computer modeling is not currently forecasting accurate thrust predictions. Should there be other things to start looking at/recording/monitoring, for EM Drive builders? So that better computer models can be used to also use that input data with factors contributing to thrust besides using only the current factors they are using now. If it comes to that?  Do you have any suggestions?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418562#msg1418562">Quote from: TheUberOverLord on 08/21/2015 07:41 PM</a>
@Dr. Rodal and others

In reference to Dr. Rodal's post here:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516

Is it possible that at this stage of actual EM Drive builds and their resulting test data ("In the public domain"). That computer based modeling might not yet include all required factors as input data to produce accurate estimates in their output data? Of all classical physics theories which could be involved, prove outside classical theories are involved or even if there are combinations of both currently taking place.

If somehow this becomes more apparent ("In the soon to be near future") that current computer modeling can't currently accurately account for the total results when those specifications are used for actual EM Drive builds. Then what's next?

Should things like internal photography and video inside cavities be used, magnetic fields and other recording and sensing devices be used in the future, during the testing of EM Drive builds?

I would like to hear what others suggested plan B's are out there to be considered if and when current computer models fail miserably to make accurate estimates. I would think others would as well.

Would you mostly all have similar plan B suggestions?

Especially with new EM Drive builds about to prove or disprove the accuracy of current computer models being used as being reasonably solid or in need of some major "Code changes" that might not even have the required mathematical formulas yet to be able to implement those "Code changes".

Don

Don

The current batch of physical tests will provide some very valuable information. The possibilities for cavity length, antenna placement and shape, input energy modes, computer automation and auto-tuning...  there is a lot to explore.
I personally am in no doubt the current spreadsheets and/or privately held mathematical models do not contain anywhere near the full spectrum of events and actions happening in relation to the tests. Warptech is following the issue of the Gravitational-mimic field (keep going there mate, you have something important waiting at the end of this), there is also potential for interaction with other presently "mysterious fields" such as dark energy and/or dark matter which may somehow play a part as these are known to react to gravitational energy. The evanescent issues are interesting and may yet become an exploration in their own right.  The whole spectrum of electron acceleration... will also come into play at some point.  Then throw superconduction in there just to multiply complexity by 100x.

You are right to be concerned about the "What if" scenarios for expanding the test regime.. but for now... one step at a time.  When this device is finished, then we can move on to the other
 
TT,  welcome back,  take care

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 11:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419385#msg1419385">Quote from: aero on 08/25/2015 02:26 AM</a>
A couple of models using SeeShell's (and Rodal's) dimensions posted earlier.

Dimensions in both cases are:

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

These dimensions on the model with spherical ends are exactly the same. The dimensions of the spherical ends are:

r1= 0.20114 m  (*small spherical radius*)
r2= 0.370852 m  (*big spherical radius*)
theta = 22.495 degrees  (*half cone angle*)

These spherical segments match exactly to the conic section. Note that the axial length is the axial length of the conic section and is not the difference in the radial distance between the two spherical sections. That distance is r2 - r1 = 0.370852 m - 0.20114 m. In the meep model shown, r2 is the inside radius of the big end spherical section while r1 is the outside radius of the small end spherical section.

Both X-Ray and I calculate the TE012 natural frequency to be 2.45 GHz with the dimensions

bigDiameter = 0.295(*meter*);
smallDiameter = 0.160(*meter*);
axialLength = 0.163(*meter*);

therefore, if you don't get a good resonance with your Meep model, it is not because of the geometry.  It must be because of something being different in Meep than in the solutions of X-Ray and me.  In the solutions of X-Ray and me, we don't have an antenna RF feed.  Therefore the difference is the antenna in your model.  The reason why Meep does not resonate is because of the antenna model you are using: two long straight parallel antennas.

Instead, to excite TE modes you should use a loop antenna.

For a cylinder, you can get away with using two parallel straight dipoles (with current going in different directions) because of the straight walls of a cylinder, and the fact that in a cylinder the solution has PLANE waves instead of spherical waves.

For Yang/Shell geometry with 6 degrees this kludgy antenna model worked because the Yang/Shell model at 6 degrees is very close to the geometry of a cylinder.

However, for larger cone angles, the waves inside the truncated cone are more spherical waves, they differ more and more from a plane wave.

The present model has a cone half-angle of 22 degrees.  The geometry is very different from a cylinder, much more conical.

Again, the best thing to do is to use a loop antenna.

If you cannot model a loop antenna you may try to use a much shorter (1 or 2 inches long) parallel dipole antenna.

Using a long straight antenna that practically spans the diameter of the truncated cone is bound to produce problems for a truncated cone geometry.  A long straight antenna really disrupts the spherical wave patterns

We knew this since even for the Yang/Shell geometry at 6 degrees cone angle, there was a severe difference between the plane of the dipole and the perpendicular plane.  Extraneous modes resulted from this distortion of the geometry produced by the straight long antenna in only one plane.

The best thing is to use a loop antenna for TE modes

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 12:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419366#msg1419366">Quote from: rfmwguy on 08/25/2015 12:24 AM</a>
Doc, nevermind. I found the original EW pic showing the drive antenna on the small end.

This is where I suspect Mr. March was going. Also he had a top-mounted 100 kW Magnetron on a concept drawing.

Its a year after your other pic.

Correction, the drive antenna was in front of the dielectric. Strange looking HDPE, almost looks infused with graphene  ;)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059514,3Bimage.pagespeed.ic.evKgm4cx-R.webp)

The dielectric insert was NOT High Density PolyEthylene (HDPE), instead it was a ceramic dielectric resonator disc with e-r=43 (relative permittivity) (the type that was early used by Shawyer in his early patents)

Based on the information on previous EM Drive threads, that aluminum frustum cavity never produced any thrust with that loop antenna located at the small end.

 That’s why NASA went back to the copper frustum with the two HDPE discs and the 13.5mm OD loop antenna located near the large OD end of the copper frustum. 

This confirms the analysis based on the Meep results post-processed with Wolfram Mathematica: NO thrust when the antenna is located at the small end because when the antenna is located at the small end, the force on the big base is compressive and it is cancelled out by the force on the lateral conical surfaces 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 12:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/25/2015 12:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419441#msg1419441">Quote from: arc on 08/25/2015 07:45 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419429#msg1419429">Quote from: TheUberOverLord on 08/25/2015 07:01 AM</a>
@TheTraveller. I asked this while I think you were away. Meaning if computer modeling is not currently forecasting accurate thrust predictions. Should there be other things to start looking at/recording/monitoring, for EM Drive builders? So that better computer models can be used to also use that input data with factors contributing to thrust besides using only the current factors they are using now. If it comes to that?  Do you have any suggestions?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418562#msg1418562">Quote from: TheUberOverLord on 08/21/2015 07:41 PM</a>
@Dr. Rodal and others

In reference to Dr. Rodal's post here:

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418516#msg1418516

Is it possible that at this stage of actual EM Drive builds and their resulting test data ("In the public domain"). That computer based modeling might not yet include all required factors as input data to produce accurate estimates in their output data? Of all classical physics theories which could be involved, prove outside classical theories are involved or even if there are combinations of both currently taking place.

If somehow this becomes more apparent ("In the soon to be near future") that current computer modeling can't currently accurately account for the total results when those specifications are used for actual EM Drive builds. Then what's next?

Should things like internal photography and video inside cavities be used, magnetic fields and other recording and sensing devices be used in the future, during the testing of EM Drive builds?

I would like to hear what others suggested plan B's are out there to be considered if and when current computer models fail miserably to make accurate estimates. I would think others would as well.

Would you mostly all have similar plan B suggestions?

Especially with new EM Drive builds about to prove or disprove the accuracy of current computer models being used as being reasonably solid or in need of some major "Code changes" that might not even have the required mathematical formulas yet to be able to implement those "Code changes".

Don

Don

The current batch of physical tests will provide some very valuable information. The possibilities for cavity length, antenna placement and shape, input energy modes, computer automation and auto-tuning...  there is a lot to explore.
I personally am in no doubt the current spreadsheets and/or privately held mathematical models do not contain anywhere near the full spectrum of events and actions happening in relation to the tests. Warptech is following the issue of the Gravitational-mimic field (keep going there mate, you have something important waiting at the end of this), there is also potential for interaction with other presently "mysterious fields" such as dark energy and/or dark matter which may somehow play a part as these are known to react to gravitational energy. The evanescent issues are interesting and may yet become an exploration in their own right.  The whole spectrum of electron acceleration... will also come into play at some point.  Then throw superconduction in there just to multiply complexity by 100x.

You are right to be concerned about the "What if" scenarios for expanding the test regime.. but for now... one step at a time.  When this device is finished, then we can move on to the other
 
TT,  welcome back,  take care

Please don't be offended but one of those EM Drives designed with help from computer models is scheduled to be tested "Today".

Personally, I see no need to delay "What if". If everything turns out to be very accurate then any discussion about "What If" could be stopped and no more time wasted on it would be required.

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 12:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419473#msg1419473">Quote from: flux_capacitor on 08/25/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Don't put an antenna at a node.  A node is location of zero amplitude.  Instead locate the antenna at an anti-node: a location of maximum amplitude.

(wav_26.gif)

The orientation of the loop antenna for a TE mode should be such that the magnetic field goes through the center of the loop.  The magnetic field in TE01 modes is oriented along the longitudinal axis of axi-symmetry.   Thus the perimeter of the antenna is perpendicular to the longitudinal axis and hence perpendicular to the longitudinal propagation direction of the wave.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 12:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419475#msg1419475">Quote from: TheUberOverLord on 08/25/2015 12:25 PM</a>
...
Please don't be offended but one of those EM Drives designed with help from computer models is scheduled to be tested "Today".

...
As previously posted, the EM Drive to be tested today has the antenna located at the small end of the cavity, while the latest computer analysis indicates that the antenna should be located at the completely opposite location: near the opposite end, near the big base. 

Thus today's test will be instructive to see what happens when the antenna is located in the opposite direction than the one recommended by the latest computer analysis and the opposite direction than the one used by NASA Eagleworks in their positive tests.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 08/25/2015 12:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419478#msg1419478">Quote from: Rodal on 08/25/2015 12:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419475#msg1419475">Quote from: TheUberOverLord on 08/25/2015 12:25 PM</a>
...
Please don't be offended but one of those EM Drives designed with help from computer models is scheduled to be tested "Today".

...
As I posted several times, the EM Drive to be tested today has the antenna located at the small end of the cavity, while the analysis indicates it should be located at the completely opposite location: near the opposite end, near the big base.

Dr. Rodal,

I do understand that and always have. I assume that there are projected thrust estimates for the EM Drive in question from computer models as it is now?

If there are and those estimates are extremely inaccurate. Then is it a foolish task to be thinking about any additional monitoring/recording for additional things during future testing which most likely will be sooner than later?

There appears to be a great void in so much as mentioning and even discussing what could or should take place for suggested additional monitoring/recording in a situation like that.

IMHO but with great respect for you and others here. Wishful thinking slows down dealing with unexpected results because the proper time was not spent in how to deal with those unexpected results. Which in the end might cause delay. Because there was no "Game Plan" on how to better test and determine, why those unexpected results are occurring.

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 01:15 PM
https://www.youtube.com/watch?v=Id-Yf2HdQ-U
ARISO Contactless Connectivity
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 01:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419476#msg1419476">Quote from: Rodal on 08/25/2015 12:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419473#msg1419473">Quote from: flux_capacitor on 08/25/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Don't put an antenna at a node.  A node is location of zero amplitude.  Instead locate the antenna at an anti-node: a location of maximum amplitude.

(wav_26.gif)

The orientation of the loop antenna for a TE mode should be such that the magnetic field goes through the center of the loop.  The magnetic field in TE01 modes is oriented along the longitudinal axis of axi-symmetry.   Thus the perimeter of the antenna is perpendicular to the longitudinal axis and hence perpendicular to the longitudinal propagation direction of the wave.

Fair enough, wrong terminology from my side. But my question is still valid for antinodes.

I wanted to talk about the centers of the blue or red "blobs" in Meep simulations.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 01:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419478#msg1419478">Quote from: Rodal on 08/25/2015 12:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419475#msg1419475">Quote from: TheUberOverLord on 08/25/2015 12:25 PM</a>
...
Please don't be offended but one of those EM Drives designed with help from computer models is scheduled to be tested "Today".

...
As previously posted, the EM Drive to be tested today has the antenna located at the small end of the cavity, while the latest computer analysis indicates that the antenna should be located at the completely opposite location: near the opposite end, near the big base. 

Thus today's test will be instructive to see what happens when the antenna is located in the opposite direction than the one recommended by the latest computer analysis and the opposite direction than the one used by NASA Eagleworks in their positive tests.
We have to consider there are many ways to excite modes within the cavity and the general meep would need to be modified (which it can be) to work with them all. Dr. Rodel in taking the CSV files and post processing with mathematica is proving a very good workaround and has given us some very insightful data.
Cavity size rules them all.
Snub (s)
Loop antenna (s) TE and TM
waveguide coupling (s) TE and TM
direct magnetron (s) TE and TM
dipole (s) TM
helical  TM?
modified helicals TM?
1/4 wave shifted dipoles TM

For me it has narrowed down to "build it and they will come", in other words select the best option at build and test, move, file, cut to fine tune it all. At  least I have the VNA and SA to do it with.

Shell
cleaned up

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 02:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419493#msg1419493">Quote from: flux_capacitor on 08/25/2015 01:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419476#msg1419476">Quote from: Rodal on 08/25/2015 12:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419473#msg1419473">Quote from: flux_capacitor on 08/25/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Don't put an antenna at a node.  A node is location of zero amplitude.  Instead locate the antenna at an anti-node: a location of maximum amplitude.

(wav_26.gif)

The orientation of the loop antenna for a TE mode should be such that the magnetic field goes through the center of the loop.  The magnetic field in TE01 modes is oriented along the longitudinal axis of axi-symmetry.   Thus the perimeter of the antenna is perpendicular to the longitudinal axis and hence perpendicular to the longitudinal propagation direction of the wave.

Fair enough, wrong terminology from my side. But my question is still valid for antinodes.

I wanted to talk about the centers of the blue or red "blobs" in Meep simulations.

I think this is right because of the asymmetry of the cavity the anti-nodes are not at 1/4 wavelengths from the side walls. Putting the antenna 1/4 wave will cause phase distortions and cancellations.


 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/25/2015 03:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419493#msg1419493">Quote from: flux_capacitor on 08/25/2015 01:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419476#msg1419476">Quote from: Rodal on 08/25/2015 12:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419473#msg1419473">Quote from: flux_capacitor on 08/25/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Don't put an antenna at a node.  A node is location of zero amplitude.  Instead locate the antenna at an anti-node: a location of maximum amplitude.

(wav_26.gif)

The orientation of the loop antenna for a TE mode should be such that the magnetic field goes through the center of the loop.  The magnetic field in TE01 modes is oriented along the longitudinal axis of axi-symmetry.   Thus the perimeter of the antenna is perpendicular to the longitudinal axis and hence perpendicular to the longitudinal propagation direction of the wave.

Fair enough, wrong terminology from my side. But my question is still valid for antinodes.

I wanted to talk about the centers of the blue or red "blobs" in Meep simulations.

Don't read to much into those blue or red "blobs" on the  latest meep images. They are only there to show the antenna location. I cut the simulation off after only 6/10th of a cycle so we can see the antenna but nothing has yet reached the side or end walls. So the blobs are only the antenna. They are located where Harminv calculates the best resonance from the antenna/cavity combination, but that is a different run, different image.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: BL on 08/25/2015 03:50 PM
Re post #1025 by rq3

Be wary of spark plug wire.  The insulation rating will be more than adequate, but they are not designed to carry appreciable current. Most spark plug wire has a resistance of several thousand ohms/ft, by design, to suppress RFI.  (One web post said that Ford specs around 7 k ohms/ft.), but plug wire from auto parts stores could vary from 5-10 k ohms/ft.  Some plug wires however have low resistance cores, but they may be hard to find.  If  you decide to go with plug wire, just be sure that you use the ones with a low resistance wire core rather than the normal resistance cores.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 04:40 PM
Seems Andrea Rossi finally got his US patent. Attached and here:

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&f=G&l=50&d=PTXT&S1=9115913&OS=9115913&RS=9115913

Appears the ECat replicators are missing using straight lithium in the fuel mix. Claimed COP 6:1.

Maybe we will be able to use LENR to replace fission reactors at home & in space powering EMDrives.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/25/2015 05:25 PM
1:15...everything ready to go. Never could convert ip cam stream to rtmp used for live streaming, so I will record with fixed camera starting in 45 minutes.

I've read a lot about modes and antenna placements without a direct link to the theory as to why this may move. So... I picked a design to get the data points.

If they are null with my current design, others have guidance. If it produces motion...well back to the drawing board for modeling em fields.

It has been a fun project, regardless. Next post will be a link to unedited video of NSF-1701's flight test.



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/25/2015 05:45 PM
A Time Zone would be helpful  8)

Fingers crossed.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 08/25/2015 05:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419569#msg1419569">Quote from: deltaMass on 08/25/2015 05:45 PM</a>
A Time Zone would be helpful  8)

Fingers crossed.

Uhhhh ... 45 min from 1:15, or about now, whatever timezone you are in ... he seems to be in EDT

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 06:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419532#msg1419532">Quote from: aero on 08/25/2015 03:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419493#msg1419493">Quote from: flux_capacitor on 08/25/2015 01:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419476#msg1419476">Quote from: Rodal on 08/25/2015 12:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419473#msg1419473">Quote from: flux_capacitor on 08/25/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Don't put an antenna at a node.  A node is location of zero amplitude.  Instead locate the antenna at an anti-node: a location of maximum amplitude.

(wav_26.gif)

The orientation of the loop antenna for a TE mode should be such that the magnetic field goes through the center of the loop.  The magnetic field in TE01 modes is oriented along the longitudinal axis of axi-symmetry.   Thus the perimeter of the antenna is perpendicular to the longitudinal axis and hence perpendicular to the longitudinal propagation direction of the wave.

Fair enough, wrong terminology from my side. But my question is still valid for antinodes.

I wanted to talk about the centers of the blue or red "blobs" in Meep simulations.

Don't read to much into those blue or red "blobs" on the  latest meep images. They are only there to show the antenna location. I cut the simulation off after only 6/10th of a cycle so we can see the antenna but nothing has yet reached the side or end walls. So the blobs are only the antenna. They are located where Harminv calculates the best resonance from the antenna/cavity combination, but that is a different run, different image.

@aero, Shell and Rodal: To clarify my mind, here is attached what I mean by putting a loop antenna near the big end "in the middle of the node lobe". My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

@X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chris Bergin on 08/25/2015 06:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419567#msg1419567">Quote from: rfmwguy on 08/25/2015 05:25 PM</a>
Next post will be a link to unedited video of NSF-1701's flight test.


God speed NSF-1701! ;D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 08/25/2015 06:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419572#msg1419572">Quote from: Eer on 08/25/2015 05:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419569#msg1419569">Quote from: deltaMass on 08/25/2015 05:45 PM</a>
A Time Zone would be helpful  8)

Fingers crossed.

Uhhhh ... 45 min from 1:15, or about now, whatever timezone you are in ... he seems to be in EDT
I believe in an earlier post he had indicated that T0 was 1400 EDT.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 06:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419574#msg1419574">Quote from: flux_capacitor on 08/25/2015 06:12 PM</a>
My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.

Excite in TE013 mode and put the loop in the middle lobe as I indicated earlier.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 06:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419580#msg1419580">Quote from: TheTraveller on 08/25/2015 06:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419574#msg1419574">Quote from: flux_capacitor on 08/25/2015 06:12 PM</a>
My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.

Excite in TE013 mode and put the loop in the middle lobe as I indicated earlier.

Climbing to the second floor won't really change the problem.

(the "middle lobe" you want to use in TE013 is barely smaller than the lower lobe, hence a loop perimeter barely smaller than what I draw, and still longer than λ/4)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/25/2015 06:48 PM
If we don't hear from rmfguy by 3:00 EDT, is there someone here who can call him and make sure he's ok?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 08/25/2015 06:49 PM
Could someone please recap what resonance mode is expected for NSF-1701, looks like he is launching a TM mode to me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/25/2015 06:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419587#msg1419587">Quote from: flux_capacitor on 08/25/2015 06:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419580#msg1419580">Quote from: TheTraveller on 08/25/2015 06:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419574#msg1419574">Quote from: flux_capacitor on 08/25/2015 06:12 PM</a>
My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.

Excite in TE013 mode and put the loop in the middle lobe as I indicated earlier.

Climbing to the second floor won't really change the problem.

(the "middle lobe" you want to use in TE013 is barely smaller than the lower lobe, hence a loop perimeter barely smaller than what I draw, and still longer than λ/4)

So don't use an antenna inside the frustum.

Follow Shawyer & Prof Yang and inject the Rf into the middle lobe of the TE013 excited frustum via a tuned and impedance matched waveguide section as in her latest paper.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 06:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419587#msg1419587">Quote from: flux_capacitor on 08/25/2015 06:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419580#msg1419580">Quote from: TheTraveller on 08/25/2015 06:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419574#msg1419574">Quote from: flux_capacitor on 08/25/2015 06:12 PM</a>
My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.

Excite in TE013 mode and put the loop in the middle lobe as I indicated earlier.

Climbing to the second floor won't really change the problem.

(the "middle lobe" you want to use in TE013 is barely smaller than the lower lobe, hence a loop perimeter barely smaller than what I draw, and still longer than λ/4)
To excite TE01 you need to excite a magnetic field in the longitudinal direction of the axis of axi-symmetry.  If you want to keep the loop perimeter  λ/4, what prevents one from making a loop  λ/4 perimeter and placing it so that its center goes through the axis of axi-symmetry?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ryan900 on 08/25/2015 07:03 PM
Is there a list of materials that the existing builds have been made of?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 07:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419587#msg1419587">Quote from: flux_capacitor on 08/25/2015 06:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419580#msg1419580">Quote from: TheTraveller on 08/25/2015 06:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419574#msg1419574">Quote from: flux_capacitor on 08/25/2015 06:12 PM</a>
My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.

Excite in TE013 mode and put the loop in the middle lobe as I indicated earlier.

Climbing to the second floor won't really change the problem.

(the "middle lobe" you want to use in TE013 is barely smaller than the lower lobe, hence a loop perimeter barely smaller than what I draw, and still longer than λ/4)

Only in for a bit for a bite.

Remember wrt the larger the loop exciting a TE mode the more it will seriously start to effect the Q. aero I believe is seeing the same situation using the 1/4 dipoles trying to maintain the higher Qs.

Also remember a loop doesn't need to be a real loop or circle either I've got to get out again but I would like for you to consider this design. Not a loop but a loop nonetheless. Spaced around the cavity in the top or the bottom. Not to scale, just for ref.

Shell
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/25/2015 07:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419574#msg1419574">Quote from: flux_capacitor on 08/25/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419532#msg1419532">Quote from: aero on 08/25/2015 03:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419493#msg1419493">Quote from: flux_capacitor on 08/25/2015 01:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419476#msg1419476">Quote from: Rodal on 08/25/2015 12:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419473#msg1419473">Quote from: flux_capacitor on 08/25/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419464#msg1419464">Quote from: Rodal on 08/25/2015 11:32 AM</a>
The best thing is to use a loop antenna for TE modes

Ok then but how do you reconcile the need to put the loop antenna into the nodes of the mode (which are several centimeters apart) and the need for the loop antenna to have a perimeter equal to 1/4 wavelength (which gives a loop diameter of 3.5 to 4.5 cm)?

Don't put an antenna at a node.  A node is location of zero amplitude.  Instead locate the antenna at an anti-node: a location of maximum amplitude.

(wav_26.gif)

The orientation of the loop antenna for a TE mode should be such that the magnetic field goes through the center of the loop.  The magnetic field in TE01 modes is oriented along the longitudinal axis of axi-symmetry.   Thus the perimeter of the antenna is perpendicular to the longitudinal axis and hence perpendicular to the longitudinal propagation direction of the wave.

Fair enough, wrong terminology from my side. But my question is still valid for antinodes.

I wanted to talk about the centers of the blue or red "blobs" in Meep simulations.

Don't read to much into those blue or red "blobs" on the  latest meep images. They are only there to show the antenna location. I cut the simulation off after only 6/10th of a cycle so we can see the antenna but nothing has yet reached the side or end walls. So the blobs are only the antenna. They are located where Harminv calculates the best resonance from the antenna/cavity combination, but that is a different run, different image.

@aero, Shell and Rodal: To clarify my mind, here is attached what I mean by putting a loop antenna near the big end "in the middle of the node lobe". My concern is how could we reconcile such a large loop with the fact its perimeter should be equal to λ/4 to trigger resonance in the cavity (with lambda being between 12 and 15 cm)?

@X_Ray, this is a simplified sketch of a loop antenna, for didactic popularization purpose ;) The important thing to consider is the location of the loop WRT the cavity walls, end plates and mode shape. For example the two horizontal rods could be build in such a way they would not electromagnetically interfere with the waves, unlike in the sketch.
You are right with the length of the wire, this could trigger other modes(field vectors along the wire). But:
1) If the dimensions of the cavity is designed for a given mode shape, that will be the dominant. The whole thing is a resonant system (RCL) with a well defined resonant frequency.
2) With the cavity length and the angle it is possible to manipulate the frequency position in the way to be sure that the other modes are as far away as possible.
3)Each conventional MW source generate the drive frequency and a noise bandwidth around, but most a small one. The used HF components are able to modify that bandwidth(cavity, antenna, antenna feed, filter, ...)
For a "clean" resonance curve other modes have to be as far as possible.

You are also right with the straight stubs to connect the loop (loop feed) they could trigger other mode shapes, if there are possible for the cavity dimensions (see 1) 2). And the stubs will lower the effectivity of the coupling.

I don't know if i would do it this way(big loop). That's why we need the simulations.

On the other hand it may be the right way to design the cone for overlapping mode shapes to generate thrust. Don't know

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/25/2015 07:33 PM
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 08/25/2015 07:37 PM
Flux capacitor,
One can visualize the cavity as a parallel resonant RLC circuit. One also seeks to not perturb it so as to cause modeing and other undesirable effects. That means you minimize the necessary coupling to that what is needed  to efficiently transfer energy but not load the circuit down which will lower the Q, lower the resonance freq. Think as the coupling loop as an inductance paralleling the RLC of the cavity, so you want to minimize it. As Shell has pointed out, there is a multitude of ways to excite this cavity, I would pick the easiest one, the loop which can be rotated to vary the coupling, the probe length can be lowered to minimize coupling.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/25/2015 07:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.
Congrats on an heroic experimental attempt!
Do you plan to vary any parameters and retest?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 08/25/2015 07:46 PM
Congrats on the test. More useful data, the screen apparently does minimize thermal ballooning effect.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/25/2015 07:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

Congratulations!  At least there is no measurable (to 20mg) convection effects. 

Were there any meep runs with your current configuration?  Thanks!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/25/2015 07:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419610#msg1419610">Quote from: deltaMass on 08/25/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.
Congrats on an heroic experimental attempt!
Do you plan to vary any parameters and retest?
Yes, I'd like to. Seems to be a lot of hand-wringing about the antenna placement. Perhaps I'll let that settle before I remount the magnetron. Its not all that difficult except side mounting does tear into the mesh. Once thing for sure, top insertion on the small base in probably off the radar for future builds.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 08/25/2015 07:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419614#msg1419614">Quote from: cee on 08/25/2015 07:46 PM</a>
Congrats on the test. More useful data, the screen apparently does minimize thermal ballooning effect.

And the wire mesh prevents the accumulation of hot gas inside the frustum. Buoyancy is an enemy to defeat in this kind of tests.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 08:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419618#msg1419618">Quote from: rfmwguy on 08/25/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419610#msg1419610">Quote from: deltaMass on 08/25/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.
Congrats on an heroic experimental attempt!
Do you plan to vary any parameters and retest?
Yes, I'd like to. Seems to be a lot of hand-wringing about the antenna placement. Perhaps I'll let that settle before I remount the magnetron. Its not all that difficult except side mounting does tear into the mesh. Once thing for sure, top insertion on the small base in probably off the radar for future builds.

CONGRATULATIONS ON AN EXCELLENT RESULT

I have NO doubt about a recommendation:

place the magnetron at the big base

1) This is consistent with my prior recommendation based on Meep/Wolfram-Mathematica runs

2) You will not need to tear into the side mesh

3) It would be inconsistent to feed from the side at this point in time.  First you need to place the magnetron at the opposite side: at the big base to compare with running the magnetron at the small base in this run.

4) If you can place the magnetron at the center of the big base, that would be best.

Anybody that wants you to tear up the sides and mount on the side should wait until the next logical test takes place: magnetron at the big base.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/25/2015 08:01 PM
Here's the video of the flight test:

Definitely not Hollywood...take it easy on me ;)

https://www.youtube.com/watch?v=FPBs6zDmhwU

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/25/2015 08:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419609#msg1419609">Quote from: cee on 08/25/2015 07:37 PM</a>
Flux capacitor,
One can visualize the cavity as a parallel resonant RLC circuit. One also seeks to not perturb it so as to cause modeing and other undesirable effects. That means you minimize the necessary coupling to that what is needed  to efficiently transfer energy but not load the circuit down which will lower the Q, lower the resonance freq. Think as the coupling loop as an inductance paralleling the RLC of the cavity, so you want to minimize it. As Shell has pointed out, there is a multitude of ways to excite this cavity, I would pick the easiest one, the loop which can be rotated to vary the coupling, the probe length can be lowered to minimize coupling.

I agree to the RLC point.

The problem is EW used such a little loop (at the sidewall) and was not able to excite the target mode this way...
Also Rodal is right, for TE01 a asymmetric excitation isnt a good plan

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/25/2015 08:04 PM
A mesh does squash two different potential thermal effects - ballooning and jetting - but leaves in place other thermal effects: mass changes due to air escape, buoyancy changes due to ambient air density changes, convective disturbances, and centre of mass changes of the frustum itself. That's six different thermal effects.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 08:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419594#msg1419594">Quote from: Rodal on 08/25/2015 06:59 PM</a>
To excite TE01 you need to excite a magnetic field in the longitudinal direction of the axis of axi-symmetry.  If you want to keep the loop perimeter  λ/4, what prevents one from making a loop  λ/4 perimeter and placing it so that its center goes through the axis of axi-symmetry?

This?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 08:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630">Quote from: flux_capacitor on 08/25/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419594#msg1419594">Quote from: Rodal on 08/25/2015 06:59 PM</a>
To excite TE01 you need to excite a magnetic field in the longitudinal direction of the axis of axi-symmetry.  If you want to keep the loop perimeter  λ/4, what prevents one from making a loop  λ/4 perimeter and placing it so that its center goes through the axis of axi-symmetry?

This?
Yes, that's what CERN recommends in prior papers I posted. 

The purpose of the loop is to excite a magnetic field.

The magnetic field is in the longitudinal direction.  The transverse field in the azimuthal direction is electric, not magnetic

Hence you want the loop to have the magnetic field going through its center, not the electric field.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/25/2015 08:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419620#msg1419620">Quote from: tchernik on 08/25/2015 07:53 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419614#msg1419614">Quote from: cee on 08/25/2015 07:46 PM</a>
Congrats on the test. More useful data, the screen apparently does minimize thermal ballooning effect.

And the wire mesh prevents the accumulation of hot gas inside the frustum. Buoyancy is an enemy to defeat in this kind of tests.

Yes, but mesh large endplate and mesh sides may contribute to the lack of thrust.  Perhaps the heating of the frustum is an important part of the effect or the mesh is allowing some form of particle to escape (or perhaps we are seeing evidence that the observed effect is the result of some form of interaction with a metallic measuring device not used here).  Given the relative ease of moving the rf source on this build, I would hope we could determine a spot near the large base to test.  If that comes back null then we are getting a null for some reason other than rf placement on this device.

Unless Shell. rmfguy (modified) or TheTraveller (health permitting) get a strong positive result I would suggest any future DIYers go back to the South African Science Fair experiment https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/ (https://www.reddit.com/r/EmDrive/comments/3gkwcz/build_complete_initial_testing_done_emdrive_build/) as the last known good build.  Build the thing, replicate the results, then start working from a known baseline (the first thing that would occur to me is testing for thrust on a metal light rig like rmfguy used).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 08:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419632#msg1419632">Quote from: Rodal on 08/25/2015 08:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630">Quote from: flux_capacitor on 08/25/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419594#msg1419594">Quote from: Rodal on 08/25/2015 06:59 PM</a>
To excite TE01 you need to excite a magnetic field in the longitudinal direction of the axis of axi-symmetry.  If you want to keep the loop perimeter  λ/4, what prevents one from making a loop  λ/4 perimeter and placing it so that its center goes through the axis of axi-symmetry?

This?
Yes, that's what CERN recommends in prior papers I posted. 

The purpose of the loop is to excite a magnetic field.

The magnetic field is in the longitudinal direction.  The transverse field in the azimuthal direction is electric, not magnetic

Hence you want the loop to have the magnetic field going through its center, not the electric field.

Ok then. I may be mistaken because I'm representing in my head the loop antenna as a flat solenoid. A solenoid there would trigger an axial magnetic field as you say, but would tighten the magnetic lobes towards the axis of axi-symmetry because of the return path of the magnetic field lines around the very small coil. An antenna may behave differently.

(t047412a.jpg)

And as X_Ray and cee said, a cavity resonates in certain mode shapes due to its dimensions, which should help stabilize the desired mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/25/2015 08:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419623#msg1419623">Quote from: Rodal on 08/25/2015 08:00 PM</a>
CONGRATULATIONS ON AN EXCELLENT RESULT

I have NO doubt about a recommendation:

place the magnetron at the big base

1) This is consistent with my prior recommendation based on Meep/Wolfram-Mathematica runs

2) You will not need to tear into the side mesh

3) It would be inconsistent to feed from the side at this point in time.  First you need to place the magnetron at the opposite side: at the big base to compare with running the magnetron at the small base in this run.

4) If you can place the magnetron at the center of the big base, that would be best.

Anybody that wants you to tear up the sides and mount on the side should wait until the next logical test takes place: magnetron at the big base.

I have to say that for experimental completeness having the magnetron at the base would be a a very good idea.  As far as I can recall, no one has done a magnetron through the base at all. 

Given the lack of convection issues at the current measurement resolution (20mg) a solid plate would work just like the top of the fusrtrum. Alternatively, some heavy wires could be used to hang the fustrum from the bottom and use the existing mesh base.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 08:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419637#msg1419637">Quote from: flux_capacitor on 08/25/2015 08:26 PM</a>
....
Ok then. I may be mistaken because I'm representing in my head the loop antenna as a flat solenoid. A solenoid there would trigger an axial magnetic field as you say, but would tighten the magnetic lobes towards the axis of axi-symmetry because of the return path of the magnetic field lines around the coil. An antenna may behave differently.
...

And as X_Ray and cee said, a cavity resonates in certain mode shapes due to its dimensions, which should help stabilize the desired mode.

Your picture shows magnetic lobes that vary in the azimuthal direction.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059902,3Bimage.pagespeed.ic.J2ifwDb_wS.webp)

What magnetic toroidal lobes in TE012 ????:

The magnetic vector component in the azimuthal direction is zero for TE012.

The magnetic vector component in the polar angle theta direction is constant in the azimuthal direction for TE012, it varies in the theta and longitudinal direction.  It does NOT vary in the azimuthal direction.  No magnetic toroidal variation in the azimuthal direction.

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=881323;image)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 08:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

There is no bad data and NO bad test! Congratulations rfmwguy!

These are the missions of the NSF-1701, to go where no frustum has gone before and the man that does what few have had the daring to do.

I'm proud to be acquainted with you and I'm sure everyone feels the same.


I think Dr. Rodel is correct for your TM mode to put that magnetron right in the center of the bottom next time you juice it up. It makes so much sense.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 08:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.


I think this is really great experimental data one of the best tests performed.  Much higher quality that Roger Shawyer's  and Yang "tests".  Unlike Roger Shawyer and Prof. Yang, rfmwguy has made available all dimensions and all data and has methodically documented what he was going to do and how he did it.

(lbP4iQj.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/25/2015 08:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419643#msg1419643">Quote from: Rodal on 08/25/2015 08:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419637#msg1419637">Quote from: flux_capacitor on 08/25/2015 08:26 PM</a>
....
Ok then. I may be mistaken because I'm representing in my head the loop antenna as a flat solenoid. A solenoid there would trigger an axial magnetic field as you say, but would tighten the magnetic lobes towards the axis of axi-symmetry because of the return path of the magnetic field lines around the coil. An antenna may behave differently.
...

And as X_Ray and cee said, a cavity resonates in certain mode shapes due to its dimensions, which should help stabilize the desired mode.

Your picture shows magnetic lobes that vary in the azimuthal direction.

What magnetic toroidal lobes in TE012 ????:

The magnetic vector component in the azimuthal direction is zero for TE012.

The magnetic vector component in the polar angle theta direction is constant in the azimuthal direction for TE012, it varies in the theta and longitudinal direction.  It does NOT vary in the azimuthal direction.  No magnetic toroidal variation in the azimuthal direction.

It is my understanding that the blue lines in Eagleworks pictures I've posted are magnetic field lines. Eagleworks even draw vectors on the right of the drawing, showing the magnetic field is swirling from one direction along the axis of axi-symmetry (where the magnetic field is the strongest) with looping return paths near the walls of the cavity in the other direction (where the magnetic field is weaker). Directions are inverted for the lobes near the other end. Are we talking about the same thing?

The picture below is from Eagleworks. I added the captions about magnetic fields.

EDIT: Good Lord, when I wrote "toroidal" I really wanted to write poloidal field lines (around a torus shape) and not toroidal field lines (in the azimuthal direction, there is no magnetic field in that direction of course) :-X
I edited the drawing in my prior post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: teitur on 08/25/2015 09:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419625#msg1419625">Quote from: rfmwguy on 08/25/2015 08:01 PM</a>
Here's the video of the flight test:

Definitely not Hollywood...take it easy on me ;)


Congratulations on an excellent test !
The setup seems very stable and if you by varying some parameters later should get a tiny thust I think the quality of your build will make it both easy to see it and also to reproduce it reliably.
Wonderful !

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/25/2015 09:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419625#msg1419625">Quote from: rfmwguy on 08/25/2015 08:01 PM</a>
Here's the video of the flight test:

Definitely not Hollywood...take it easy on me ;)

https://www.youtube.com/watch?v=FPBs6zDmhwU

I'm not convinced you have a totally null result.

If you compare the frames at timestamp 2:50  (no weight), 3:35 (calibration weight) and 10:49 (100% power)  and just flip between the frames, there is displacement, or at least my feeble eyes delude me so.

Whether that's the device or some kind of systematic drift is a different issue, but the measurement points are not static.  The laser shows drift while the rest of the image elements are unchanged in position.  Try flipping between those times while paused.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/25/2015 10:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

Congratulations on your efforts.
Did you get my PM?
As I said, the thing is that the galinstan is a heavy alloy, 6 times heavier than water,  so you need a bit more thrust to overcome the buoyancy force. Those 3 wires are quite thick so to avoid oscillating or the frustum standing still, you need a several dozen milinewtons more. In addition the emdrive is ballooning.
So my recommendation is to  place the magnetron close to the big end or at the center of it in order to get more unbalanced force and/or turn the cavity upside down.
Best of luck.
Peter.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/25/2015 10:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419647#msg1419647">Quote from: flux_capacitor on 08/25/2015 08:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419643#msg1419643">Quote from: Rodal on 08/25/2015 08:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419637#msg1419637">Quote from: flux_capacitor on 08/25/2015 08:26 PM</a>
....
Ok then. I may be mistaken because I'm representing in my head the loop antenna as a flat solenoid. A solenoid there would trigger an axial magnetic field as you say, but would tighten the magnetic lobes towards the axis of axi-symmetry because of the return path of the magnetic field lines around the coil. An antenna may behave differently.
...

And as X_Ray and cee said, a cavity resonates in certain mode shapes due to its dimensions, which should help stabilize the desired mode.

Your picture shows magnetic lobes that vary in the azimuthal direction.

What magnetic toroidal lobes in TE012 ????:

The magnetic vector component in the azimuthal direction is zero for TE012.

The magnetic vector component in the polar angle theta direction is constant in the azimuthal direction for TE012, it varies in the theta and longitudinal direction.  It does NOT vary in the azimuthal direction.  No magnetic toroidal variation in the azimuthal direction.

It is my understanding that the blue lines in Eagleworks pictures I've posted are magnetic field lines. Eagleworks even draw vectors on the right of the drawing, showing the magnetic field is swirling from one direction along the axis of axi-symmetry (where the magnetic field is the strongest) with looping return paths near the walls of the cavity in the other direction (where the magnetic field is weaker). Directions are inverted for the lobes near the other end. Are we talking about the same thing?

The picture below is from Eagleworks. I added the captions about magnetic fields.

EDIT: Good Lord, when I wrote "toroidal" I really wanted to write poloidal field lines (around a torus shape) and not toroidal field lines (in the azimuthal direction, there is no magnetic field in that direction of course) :-X
I edited the drawing in my prior post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630).

Thank you for your patience.  Yes, now I see what you drew, I was thinking of the word "toroidal" so I saw them in the azimuthal direction.  Now I understand that what you are drawing are the contours shown in the plots below:

Please take a close look at the contours and vector fields.  What we want to excite is the magnetic longitudinal field.  They have different nodes and antinodes than the magnetic field in the theta polar direction !
The anti-node (the maximum) of what we want to excite: the magnetic field in the longitudinal direction, corresponds to the node (the zero) of the magnetic field in the polar theta direction.



Please take a look at the red section of the longitudinal vector field: the antenna loop can have a very small perimeter indeed as long as it is located at the center of the axis of axi-symmetry, at the correct location

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 08/25/2015 10:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630">Quote from: flux_capacitor on 08/25/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419594#msg1419594">Quote from: Rodal on 08/25/2015 06:59 PM</a>
To excite TE01 you need to excite a magnetic field in the longitudinal direction of the axis of axi-symmetry.  If you want to keep the loop perimeter  λ/4, what prevents one from making a loop  λ/4 perimeter and placing it so that its center goes through the axis of axi-symmetry?

This?

What about placing a polarizing metal grid inside the cavity? Would that, depending on the orientation, not enhance a TE mode? You'd probably got some losses in average Q, but a much cleaner resonance mode?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/25/2015 10:51 PM
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TTexas83 on 08/25/2015 10:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419625#msg1419625">Quote from: rfmwguy on 08/25/2015 08:01 PM</a>
Here's the video of the flight test:

Definitely not Hollywood...take it easy on me ;)

https://www.youtube.com/watch?v=FPBs6zDmhwU
First, congrats on the experimentation. But I'm a bit confused:
Everyone, including yourself, have been saying this was a null result. When I heard this, I was a bit disappointed and watched the video anyways. It is clear, when you skip through the test[from start to near-end] that the beam has moved. Whether or not that means there was thrust- who knows. But it is, indeed, moving, so something has to be causing that.
I think the apparatus moved up since the beam went down?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Econocritic on 08/25/2015 10:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

With the small end down wouldn't any thrust be acting against thermal buoyancy?  Would have more confidence in the apparent null result after the same test with small end up.  If still null then the effectiveness of the wire mesh against a balloon type effect would be further demonstrated.  Greater displacement shown with small end up would be very valuable data. Tajmar registered upward movement in both up and down orientations and had to take the difference, if my memory is correct. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/25/2015 10:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 08/25/2015 11:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?
For comparison, could someone do the same with the before, during and after positions of the laser light when he added the 200mg (I think) calibration weight to the frustrum before he ran his test?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/25/2015 11:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419684#msg1419684">Quote from: Eer on 08/25/2015 11:02 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?
For comparison, could someone do the same with the before, during and after positions of the laser light when he added the 200mg (I think) calibration weight to the frustrum before he ran his test?

Can you give me the time stamps on that?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 08/25/2015 11:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Those frames are at 2:50, 3:35, and 10:49. Positional changes like that are expected with rfmwguy moving around the lab.

Frame grabs need to be done as the power cycles during a test run. The first run with the 30% power cycle over five minutes would be best, since the rig needs time to settle when rfmwguy starts it and leaves the room. Wait until the first minute into the run and then grab frames. You can hear the power cycle on and off.

Staring at the screen I didn't notice any movement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 08/25/2015 11:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419687#msg1419687">Quote from: RonM on 08/25/2015 11:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Those frames are at 2:50, 3:35, and 10:49. Positional changes like that are expected with rfmwguy moving around the lab.

Frame grabs need to be done as the power cycles during a test run. The first run with the 30% power cycle over five minutes would be best, since the rig needs time to settle when rfmwguy starts it and leaves the room. Wait until the first minute into the run and then grab frames. You can hear the power cycle on and off.

Staring at the screen I didn't notice any movement.

I found before to be anytime before 3:00.  During the test I see around 3:24 (or you 3:35 is fine) but I would take the "after" as being around 4:00 - NOT the 10:49, which is after all the tests.  Okay, maybe include that, too.

My goal is to see the deflection due strictly to the calibration test - before adding the weight, while the weight is added, and after removing the weight.  The final position should be the same as the beginning position of the powered runs.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/26/2015 12:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419688#msg1419688">Quote from: Eer on 08/25/2015 11:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419687#msg1419687">Quote from: RonM on 08/25/2015 11:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Those frames are at 2:50, 3:35, and 10:49. Positional changes like that are expected with rfmwguy moving around the lab.

Frame grabs need to be done as the power cycles during a test run. The first run with the 30% power cycle over five minutes would be best, since the rig needs time to settle when rfmwguy starts it and leaves the room. Wait until the first minute into the run and then grab frames. You can hear the power cycle on and off.

Staring at the screen I didn't notice any movement.

I found before to be anytime before 3:00.  During the test I see around 3:24 (or you 3:35 is fine) but I would take the "after" as being around 4:00 - NOT the 10:49, which is after all the tests.  Okay, maybe include that, too.

My goal is to see the deflection due strictly to the calibration test - before adding the weight, while the weight is added, and after removing the weight.  The final position should be the same as the beginning position of the powered runs.

Added a bar using gimps rectangle tool.  It looks like the rig returned to roughly its initial state after the calibration test.  Can anyone work out the downward deflection?  My gut it telling me that it's more than 200mg of force.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 12:12 AM
When I designed NSF-1701, I built it to be reconfigurable.

So I did just that...Doc, here's the new setup with the magnetron centered on the big base as you recommended. Its all ready for a second flight test!

But, its been a big day and I need a break form the shop. I'll test it again in a couple of days.

A heartfelt thanks for all the support!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/26/2015 12:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419647#msg1419647">Quote from: flux_capacitor on 08/25/2015 08:52 PM</a>
...

EDIT: Good Lord, when I wrote "toroidal" I really wanted to write poloidal field lines (around a torus shape) and not toroidal field lines (in the azimuthal direction, there is no magnetic field in that direction of course) :-X
I edited the drawing in my prior post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630).

I knew what you meant. What @Rodal calls azimuthal, I refer to as "circular", when the flux lines are circling the minor diameter, I call it "toroidal" like you did. The word "poloidal" was not in my vocabulary. :(
Thanks!
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 12:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419666#msg1419666">Quote from: Mr. Peter on 08/25/2015 10:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

Congratulations on your efforts.
Did you get my PM?
As I said, the thing is that the galinstan is a heavy alloy, 6 times heavier than water,  so you need a bit more thrust to overcome the buoyancy force. Those 3 wires are quite thick so to avoid oscillating or the frustum standing still, you need a several dozen milinewtons more. In addition the emdrive is ballooning.
So my recommendation is to  place the magnetron close to the big end or at the center of it in order to get more unbalanced force and/or turn the cavity upside down.
Best of luck.
Peter.
Thanks peter, yes I got the pm but was too busy setting up the flight test. Good comments. Yes galinstan is heavier than I would like an believe it dampens small movements and surface tension is an undesireable effect. Wish I had some other liquid to conduct the supply voltages.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 08/26/2015 12:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419687#msg1419687">Quote from: RonM on 08/25/2015 11:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Those frames are at 2:50, 3:35, and 10:49. Positional changes like that are expected with rfmwguy moving around the lab.

Frame grabs need to be done as the power cycles during a test run. The first run with the 30% power cycle over five minutes would be best, since the rig needs time to settle when rfmwguy starts it and leaves the room. Wait until the first minute into the run and then grab frames. You can hear the power cycle on and off.

Staring at the screen I didn't notice any movement.

I grabbed three frames during the five minute run when the power was off (5:25, 6:00, and 6:25) and three frames when the power was on (5:45, 6:10, and 6:35). Then I selected a point in the pattern to measure the pixel location. I looked at each frame at 500% so I could easily see the pixels. Each one is at the same location within +/- 1 pixel. There isn't any appreciable movement at the level of resolution of this experiment.

It is a null result.

The stability of rfmwguy's setup is impressive. This is good clean data that sets an upper limit to any thrust made by NSF-1701. Of course, the antenna location may not be optimal, but Dr. Rodal's suggested follow on test will see if the meep analysis helps.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/26/2015 12:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419695#msg1419695">Quote from: rfmwguy on 08/26/2015 12:12 AM</a>
When I designed NSF-1701, I built it to be reconfigurable.

So I did just that...Doc, here's the new setup with the magnetron centered on the big base as you recommended. Its all ready for a second flight test!

But, its been a big day and I need a break form the shop. I'll test it again in a couple of days.

A heartfelt thanks for all the support!

Now that's what I like! An engineer who's doesn't waste any time! Excellent! :)
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 12:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419699#msg1419699">Quote from: rfmwguy on 08/26/2015 12:24 AM</a>
Thanks peter, yes I got the pm but was too busy setting up the flight test. Good comments. Yes galinstan is heavier than I would like an believe it dampens small movements and surface tension is an undesireable effect. Wish I had some other liquid to conduct the supply voltages.
Of course, it's current-carrying capability that's at stake here. I don't think these are too severe - maybe 10 Amps for the heater?
You might want to experiment with common low-density electrolytes - like salt water.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/26/2015 12:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419699#msg1419699">Quote from: rfmwguy on 08/26/2015 12:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419666#msg1419666">Quote from: Mr. Peter on 08/25/2015 10:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

Congratulations on your efforts.
Did you get my PM?
As I said, the thing is that the galinstan is a heavy alloy, 6 times heavier than water,  so you need a bit more thrust to overcome the buoyancy force. Those 3 wires are quite thick so to avoid oscillating or the frustum standing still, you need a several dozen milinewtons more. In addition the emdrive is ballooning.
So my recommendation is to  place the magnetron close to the big end or at the center of it in order to get more unbalanced force and/or turn the cavity upside down.
Best of luck.
Peter.
Thanks peter, yes I got the pm but was too busy setting up the flight test. Good comments. Yes galinstan is heavier than I would like an believe it dampens small movements and surface tension is an undesireable effect. Wish I had some other liquid to conduct the supply voltages.

You had mentioned the HV test lead wire. That stuff is super flexible, and you don't need a large gauge. Perhaps, rather than using galinstan, just connect it directly using the twisted wires, but leave enough slack for movement. The weight of the wire may be less resistance than the galinstan.

I would also do something to sharpen up that laser dot with a white background, so the lines can be seen. Someone suggested graph paper, but the camera would have to be carefully focused on the graph, not the background.
Todd
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/26/2015 12:45 AM
Might I suggest rmfguy contact his local camera shot about renting some equipment.  Put a DSLR on a heavy duty pod and use a manual (wire) remote release to trigger it before the start, halfway through and near the end of each run.  Also a thermal camera on the frustum would be helpful.  I have to think that heat is involved in any kind of effect that is slow to develop and then lingers 

I would also suggest setting up the experiment so that light levels remain constant and setting the DSLRs auto-metering system to adjust the exposure time.  A change in exposure time might indicate a dimming of the laser, though since this rig uses handmade pinhole I'm not sure that's indicative of much of anything.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TTexas83 on 08/26/2015 12:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419700#msg1419700">Quote from: RonM on 08/26/2015 12:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419687#msg1419687">Quote from: RonM on 08/25/2015 11:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Those frames are at 2:50, 3:35, and 10:49. Positional changes like that are expected with rfmwguy moving around the lab.

Frame grabs need to be done as the power cycles during a test run. The first run with the 30% power cycle over five minutes would be best, since the rig needs time to settle when rfmwguy starts it and leaves the room. Wait until the first minute into the run and then grab frames. You can hear the power cycle on and off.

Staring at the screen I didn't notice any movement.

I grabbed three frames during the five minute run when the power was off (5:25, 6:00, and 6:25) and three frames when the power was on (5:45, 6:10, and 6:35). Then I selected a point in the pattern to measure the pixel location. I looked at each frame at 500% so I could easily see the pixels. Each one is at the same location within +/- 1 pixel. There isn't any appreciable movement at the level of resolution of this experiment.

It is a null result.

The stability of rfmwguy's setup is impressive. This is good clean data that sets an upper limit to any thrust made by NSF-1701. Of course, the antenna location may not be optimal, but Dr. Rodal's suggested follow on test will see if the meep analysis helps.
How do you know whether or not the power was on or off at those times and how are you ignoring the screen grabs with time stamps of what other people have posted?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tleach on 08/26/2015 12:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419700#msg1419700">Quote from: RonM on 08/26/2015 12:30 AM</a>
It is a null result.

The stability of rfmwguy's setup is impressive. This is good clean data that sets an upper limit to any thrust made by NSF-1701. Of course, the antenna location may not be optimal, but Dr. Rodal's suggested follow on test will see if the meep analysis helps.

Well, I think we can definitively state that any theory that doesn't take into account factors like antenna/waveguide placement (and hence TE and/or TM modes) into account is incomplete at best.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/26/2015 01:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419695#msg1419695">Quote from: rfmwguy on 08/26/2015 12:12 AM</a>
When I designed NSF-1701, I built it to be reconfigurable.

So I did just that...Doc, here's the new setup with the magnetron centered on the big base as you recommended. Its all ready for a second flight test!

But, its been a big day and I need a break form the shop. I'll test it again in a couple of days.

A heartfelt thanks for all the support!

That's a very nicely built apparatus.   I'm not surprised at the results given you have virtually eliminated any bouyancy effects.   One suggestion for everyone:   Since this em-drive business is so far from the mainstream of accepted scientific theory and getting even further every day why not use a more off-beat measurement system?   Instead of mgram-F  = 9.8 uN why not use dynes, the CGS unit of force?    1 mGram-F = 1 dyne.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/26/2015 01:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419709#msg1419709">Quote from: zen-in on 08/26/2015 01:07 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419695#msg1419695">Quote from: rfmwguy on 08/26/2015 12:12 AM</a>
When I designed NSF-1701, I built it to be reconfigurable.

So I did just that...Doc, here's the new setup with the magnetron centered on the big base as you recommended. Its all ready for a second flight test!

But, its been a big day and I need a break form the shop. I'll test it again in a couple of days.

A heartfelt thanks for all the support!

That's a very nicely built apparatus.   I'm not surprised at the results given you have virtually eliminated any bouyancy effects.   One suggestion for everyone:   Since this em-drive business is so far from the mainstream of accepted scientific theory and getting even further every day why not use a more off-beat measurement system?   Instead of mgram-F  = 9.8 uN why not use dynes, the CGS unit of force?    1 mGram-F = 1 dyne.

Because if this actually works we might have the live with that forever.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/26/2015 01:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419666#msg1419666">Quote from: Mr. Peter on 08/25/2015 10:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419605#msg1419605">Quote from: rfmwguy on 08/25/2015 07:33 PM</a>
NSF-1701 update - Test complete! Myself and the whole assembly came through without a scratch. I started this project with the commitment to report on exactly what I measured. What I measured was no apparent movement of the fulcrum in response to the magnetron being powered on. However, my ability to measure below about 20 mg of gram-force is just not there.

Therefore, in the configuration of the frustum with power insertion from the small base, 3.5 cm from the side wall; the result is Null to the best of my knowledge.

The video is still uploading and will be for some time. I'll post a link when it becomes available. Those of you who may want to download it and zoom in tightly on the laser target for further analysis are welcomed to do so. Power on is easily noted by transformer hum.

Congratulations on your efforts.
Did you get my PM?
As I said, the thing is that the galinstan is a heavy alloy, 6 times heavier than water,  so you need a bit more thrust to overcome the buoyancy force. Those 3 wires are quite thick so to avoid oscillating or the frustum standing still, you need a several dozen milinewtons more. In addition the emdrive is ballooning.
So my recommendation is to  place the magnetron close to the big end or at the center of it in order to get more unbalanced force and/or turn the cavity upside down.
Best of luck.
Peter.

Why not just use salt water instead of the galinstan?   The difference in resistance is negligible given the high voltage.   One caveat to this suggestion:   There may be some boil-off and possible arcing if a longer duration test is done.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/26/2015 01:26 AM
Ok, stupid question time:

Do we have a calculation/guesstimate as to the amount of thrust the NSF 1701 should produce with the magnetron at the big base?

And given the limitations of the measuring apparatus, would he be able to detect thrust in that range? 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 08/26/2015 01:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419706#msg1419706">Quote from: TTexas83 on 08/26/2015 12:49 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419700#msg1419700">Quote from: RonM on 08/26/2015 12:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419687#msg1419687">Quote from: RonM on 08/25/2015 11:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419682#msg1419682">Quote from: SeeShells on 08/25/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419677#msg1419677">Quote from: SteveD on 08/25/2015 10:51 PM</a>
Um, looks like the force (if any) was toward the large base (i.e up).  Somebody with some batter software than snipit and GIMP want to do a better screen capture and put some lines on this thing?

Enhance.... enhance more, zoom, increase contrast. It is definitely positional change.

Out to the shop again....

Those frames are at 2:50, 3:35, and 10:49. Positional changes like that are expected with rfmwguy moving around the lab.

Frame grabs need to be done as the power cycles during a test run. The first run with the 30% power cycle over five minutes would be best, since the rig needs time to settle when rfmwguy starts it and leaves the room. Wait until the first minute into the run and then grab frames. You can hear the power cycle on and off.

Staring at the screen I didn't notice any movement.

I grabbed three frames during the five minute run when the power was off (5:25, 6:00, and 6:25) and three frames when the power was on (5:45, 6:10, and 6:35). Then I selected a point in the pattern to measure the pixel location. I looked at each frame at 500% so I could easily see the pixels. Each one is at the same location within +/- 1 pixel. There isn't any appreciable movement at the level of resolution of this experiment.

It is a null result.

The stability of rfmwguy's setup is impressive. This is good clean data that sets an upper limit to any thrust made by NSF-1701. Of course, the antenna location may not be optimal, but Dr. Rodal's suggested follow on test will see if the meep analysis helps.
How do you know whether or not the power was on or off at those times and how are you ignoring the screen grabs with time stamps of what other people have posted?

You can tell when the power is on or off by the sound, as rfmwguy suggested. I'm using screen grabs only during the five minute run. The whole point is to see what happens during a test run. The movement at random moments during the video can be the result of rfmwguy moving around the room.

However, I have noticed a problem with my analysis. The point I picked is an artifact of the pattern caused by the curved mirror. If I click through the screen captures and concentrate on the brightest part of the laser, it drifts downward during the run. Now if NSF-1701 is producing thrust, the beam should move in one direction when on and back to the starting point when off. If the balance doesn't go back to its "zero" after a small force is applied, then there might actually be some thrust.

This drifting downward does match with the screen grabs the others have posted.

I'll have to retract my null result statement.

I think for the next experiment, rfmwguy should use a flat mirror instead of the curved mirror. A single spot would be easier to measure.

I also suggest that others grab frames during the test runs and look for movement. And was there any movement between the test runs indicating the balance was drifting downwards even with the device turned off.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/26/2015 02:49 AM
Great work rfmwguy!

Here is a montage of how the region of interest looks throughout the whole movie (stretched in Y to make things clearer).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sherman on 08/26/2015 02:55 AM
Hi Guys,

First ever post here, but I've been watching these threads with interest for several months.

Like a couple of others, I thought I would post my own screenshot comparison of the first test of NSF-1701

Methodology:

1. Download video file from Youtube
2. Playback video in MPC-HC, and capture screenshots using the inbuilt tool (F5 key). This ensures all captures are identical in image size, and there is no need to use any features in the video to line up, as the camera position does not change.
3. Load screenshots into 2D CAD (draftsight in this case). I manually entered the insertion point for each image so that the only change was the X co-ordinate. Image scale was set to 1 and rotation angle to 0
4. A simple line was drawn through the approximate centre of the first laser dot, and extended out to all images


I took 5 screenshots. They are at the following positions:

01:41 - Before calibration Weight
03:40 - While calibration weight is in place
04:13 - After calibration weight has been removed
09:00 - During a cycle of the magnetron at the end of the 30% test
10:59 - During the 100% test

Attached are a screenshot from Draftsight, as well as the drawing and referenced images in DWG format (in a zip file)

I'll leave it to those smarter than me to come to any conclusions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sherman on 08/26/2015 03:16 AM
I decided to add one more screenshot. The new order is as follows (left to right)

01:41 - Before calibration Weight
03:40 - While calibration weight is in place
04:13 - After calibration weight has been removed
08:27 - During 5 minute 30% test, while the magnetron is OFF
09:00 - During a cycle of the magnetron at the end of the 30% test
10:59 - During the 100% test
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 03:22 AM
Holy Canolli! Crowdsourced data analysis! Fantastic  :D
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 08/26/2015 03:23 AM
Great work Croppa and sherman!

Looks like there is movement only during the test runs. Unlike with the test mass, it looks like the thrust is light enough that the balance does not return to its original position. Still, it could be some sort of thermal effects, but we are getting closer to the truth.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/26/2015 03:48 AM
I am totally with deltaMass!  This is excellent work guys!!  My God this forum is amazing!!! :D

One thing that makes me wonder is why the fustrum never returns to its original position.  Croppa's excellent montage shows this best in post 1130.  It looks like something shifted or there is some type of ballooning effect (from what is not clear to me).  Alternatively, we really are creating little warp drives!   ;D

rmfguy- I am not sure how to put this but we may need the magnetron back at the top after all!!!  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/26/2015 04:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419742#msg1419742">Quote from: demofsky on 08/26/2015 03:48 AM</a>
I am totally with deltaMass!  This is excellent work guys!!  My God this forum is amazing!!! :D

One thing that makes me wonder is why the fustrum never returns to its original position.  Croppa's excellent montage shows this best in post 1130.  It looks like something shifted or there is some type of ballooning effect (from what is not clear to me).  Alternatively, we really are creating little warp drives!   ;D

rmfguy- I am not sure how to put this but we may need the magnetron back at the top after all!!!  :)

Probably because this is the way a knife edge fulcrum behaves. It sticks. It would be better to use ball bearings I think.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 04:56 AM
Yes, and another source of stiction, which rfmwguy has already mentioned, is the surface tension of the Galinstan.

The data shows the frustum apparently thrusting big-end-forward, or upwards. It's in the opposite direction to the calibration weight. The magnitude appears greater than the 2 mN (0.2 gm-wt) calibration. Maybe around 10 mN?

Note that we're not seeing anything resembling constant acceleration here. I believe that the way this is supposed to work is that the observed displacement is proportional to the apparent thrust.

I think we could do with better characterisation of the balance. Is it linear? Is the rate of change of displacement linearly proportional to the change in calibration weight?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: mdspacefan on 08/26/2015 05:12 AM
I noticed in Croppas montage that the rate of change in the deflection between the 30% test and the 100% test increases.  Assuming a constant amount of time per slice in his montage, drawing a line along the laser deflection point between the beginning and the end of each test segment seems to show a fairly constant rate of change. Comparing the slope of the two lines indicates a differing rate of change in the deflection between the two test segments. Not sure what to make of this, but maybe it will mean something to someone with better image editing and analysis skills
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/26/2015 05:39 AM
Here is a better version of the montage. It's made from 1 pixel wide slices fixed on the laser spot. Each slice represents 0.25 seconds of the movie. They're stretched 8 times vertically and autocontrasted individually so the blue lines are where the image was dark (i.e rfmwguy in front of the laser).

I'll leave it to you guys to decide what's causing those "steps" during the 5 minute run... ;) :-\
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/26/2015 06:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419746#msg1419746">Quote from: WarpTech on 08/26/2015 04:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419742#msg1419742">Quote from: demofsky on 08/26/2015 03:48 AM</a>
I am totally with deltaMass!  This is excellent work guys!!  My God this forum is amazing!!! :D

One thing that makes me wonder is why the fustrum never returns to its original position.  Croppa's excellent montage shows this best in post 1130.  It looks like something shifted or there is some type of ballooning effect (from what is not clear to me).  Alternatively, we really are creating little warp drives!   ;D

rmfguy- I am not sure how to put this but we may need the magnetron back at the top after all!!!  :)

Probably because this is the way a knife edge fulcrum behaves. It sticks. It would be better to use ball bearings I think.
Todd
And additionally, the magnetron was still hot. Another thing is that the inertia of such a long balance scale is high, so no quick reaction.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/26/2015 06:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419752#msg1419752">Quote from: Mr. Peter on 08/26/2015 06:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419746#msg1419746">Quote from: WarpTech on 08/26/2015 04:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419742#msg1419742">Quote from: demofsky on 08/26/2015 03:48 AM</a>
I am totally with deltaMass!  This is excellent work guys!!  My God this forum is amazing!!! :D

One thing that makes me wonder is why the fustrum never returns to its original position.  Croppa's excellent montage shows this best in post 1130.  It looks like something shifted or there is some type of ballooning effect (from what is not clear to me).  Alternatively, we really are creating little warp drives!   ;D

rmfguy- I am not sure how to put this but we may need the magnetron back at the top after all!!!  :)

Probably because this is the way a knife edge fulcrum behaves. It sticks. It would be better to use ball bearings I think.
Todd
And additionally, the magnetron was still hot. Another thing is that the inertia of such a long balance scale is high, so no quick reaction.

Yes.  Also, the actual thrust was very low and so the beam only moved fractionally. This means that the force available to move the beam back is also small, particularly compared to the mass of the beam. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: teitur on 08/26/2015 07:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419695#msg1419695">Quote from: rfmwguy on 08/26/2015 12:12 AM</a>
When I designed NSF-1701, I built it to be reconfigurable.

So I did just that...Doc, here's the new setup with the magnetron centered on the big base as you recommended. Its all ready for a second flight test!

But, its been a big day and I need a break form the shop. I'll test it again in a couple of days.

A heartfelt thanks for all the support!

I simple optical trick that may improve the sharpness of the laser dot in the movie is to move the camera back as far as possible and then to use the zoom (I hope your camera has one). This will make the paper with the laser dot sharper when you focus on the rig.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/26/2015 07:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419756#msg1419756">Quote from: demofsky on 08/26/2015 06:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419752#msg1419752">Quote from: Mr. Peter on 08/26/2015 06:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419746#msg1419746">Quote from: WarpTech on 08/26/2015 04:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419742#msg1419742">Quote from: demofsky on 08/26/2015 03:48 AM</a>
I am totally with deltaMass!  This is excellent work guys!!  My God this forum is amazing!!! :D

One thing that makes me wonder is why the fustrum never returns to its original position.  Croppa's excellent montage shows this best in post 1130.  It looks like something shifted or there is some type of ballooning effect (from what is not clear to me).  Alternatively, we really are creating little warp drives!   ;D

rmfguy- I am not sure how to put this but we may need the magnetron back at the top after all!!!  :)

Probably because this is the way a knife edge fulcrum behaves. It sticks. It would be better to use ball bearings I think.
Todd
And additionally, the magnetron was still hot. Another thing is that the inertia of such a long balance scale is high, so no quick reaction.

Yes.  Also, the actual thrust was very low and so the beam only moved fractionally. This means that the force available to move the beam back is also small, particularly compared to the mass of the beam.

Particularly compared to the mass of the beam so loaded.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: andygood on 08/26/2015 09:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419750#msg1419750">Quote from: Croppa on 08/26/2015 05:39 AM</a>
Here is a better version of the montage. It's made from 1 pixel wide slices fixed on the laser spot. Each slice represents 0.25 seconds of the movie. They're stretched 8 times vertically and autocontrasted individually so the blue lines are where the image was dark (i.e rfmwguy in front of the laser).

I'll leave it to you guys to decide what's causing those "steps" during the 5 minute run... ;) :-\

Nice work! Is there any (relatively easy) way that you could add a time-index label along the X axis, and also mark the points where power is turned on and off?

I'm at work right now  :'(, so I can't have a go at that myself...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/26/2015 10:52 AM
Huge congratulations rfmwguy! My practical skills are beyond weak, I can only stand in awe!

Two points though: if you had announced very positive results, sceptics would be demanding that you turned the apparatus upside down to eliminate buoyancy effects. However, a (nearly) null result could just as easily come from thrust down and buoyancy up. I would join the other commenter suggesting that you repeat the test upside-down, same with any future tests, and indeed for any future replicators.

Second, am I right this is the first test with a mesh frustrum? In determining that it is safe to move from a copper can to a mesh 'can', we are making assumptions about how the thing works which may not be valid (because we don't know how it works). Mesh might not be the way to go...

Your calibration was 200mg, 2x10^-4 kg, so circa 2mN. If the crowd-sourced analysis is right, the deflection seen is a modest multiple of that in the opposite direction. That is still several orders of magnitude more force/watt than a photon rocket, if it is a true reflection of the thrust produced.

Once again, fantastic work, keep going!

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 11:10 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419730#msg1419730">Quote from: Croppa on 08/26/2015 02:49 AM</a>
Great work rfmwguy!

Here is a montage of how the region of interest looks throughout the whole movie (stretched in Y to make things clearer).
This is about as cool as it gets! Well done...the downward trend is puzzling, which means the device is lifting, but not in a way id expect with thermals. Have to think about that for a while...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 11:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419735#msg1419735">Quote from: sherman on 08/26/2015 03:16 AM</a>
I decided to add one more screenshot. The new order is as follows (left to right)

01:41 - Before calibration Weight
03:40 - While calibration weight is in place
04:13 - After calibration weight has been removed
08:27 - During 5 minute 30% test, while the magnetron is OFF
09:00 - During a cycle of the magnetron at the end of the 30% test
10:59 - During the 100% test
Boom! Id say ur first post was a winner! Thanks!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 11:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419794#msg1419794">Quote from: RERT on 08/26/2015 10:52 AM</a>
Huge congratulations rfmwguy! My practical skills are beyond weak, I can only stand in awe!

Two points though: if you had announced very positive results, sceptics would be demanding that you turned the apparatus upside down to eliminate buoyancy effects. However, a (nearly) null result could just as easily come from thrust down and buoyancy up. I would join the other commenter suggesting that you repeat the test upside-down, same with any future tests, and indeed for any future replicators.

Second, am I right this is the first test with a mesh frustrum? In determining that it is safe to move from a copper can to a mesh 'can', we are making assumptions about how the thing works which may not be valid (because we don't know how it works). Mesh might not be the way to go...

Your calibration was 200mg, 2x10^-4 kg, so circa 2mN. If the crowd-sourced analysis is right, the deflection seen is a modest multiple of that in the opposite direction. That is still several orders of magnitude more force/watt than a photon rocket, if it is a true reflection of the thrust produced.

Once again, fantastic work, keep going!

R.
Good thoughts here, I was quick to say null and learned that it takes time to properly analyze data. NSF folks are schooling me on this fact...I'm really impressed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 11:26 AM
@rfmwguy:
How do you reseal the hole left behind when you relocate the magnetron?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/26/2015 12:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419799#msg1419799">Quote from: deltaMass on 08/26/2015 11:26 AM</a>
@rfmwguy:
How do you reseal the hole left behind when you relocate the magnetron?

With a magnetron hole resealer?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 12:56 PM
They still sell those?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 01:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419799#msg1419799">Quote from: deltaMass on 08/26/2015 11:26 AM</a>
@rfmwguy:
How do you reseal the hole left behind when you relocate the magnetron?
Good question. I replaced the entire top plate with a new board. No holes. I also replace the screen with a solid board, so only thing mesh now is frustum sides.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 01:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419808#msg1419808">Quote from: TheTraveller on 08/26/2015 12:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419799#msg1419799">Quote from: deltaMass on 08/26/2015 11:26 AM</a>
@rfmwguy:
How do you reseal the hole left behind when you relocate the magnetron?

With a magnetron hole resealer?
Yes, I watched that corny TV commercial for Flex Seal and thought it was the perfect solution  ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Giovanni DS on 08/26/2015 01:19 PM
The magnetron should generate quite a bit of heat and the scale could dilate asymmetrically, this could be mistaken for thrust. Has this possible issue been considered?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 01:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419814#msg1419814">Quote from: Giovanni DS on 08/26/2015 01:19 PM</a>
The magnetron should generate quite a bit of heat and the scale could dilate asymmetrically, this could be mistaken for thrust. Has this possible issue been considered?
Yes, it was in my list of 6 different thermal effects.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/26/2015 01:42 PM
All these interesting questions could be answered with a control experiment consisting of a cavity having similar dimensions but being cylindrical, producing null thrust. This should characterize thermal effects.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/26/2015 02:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419698#msg1419698">Quote from: WarpTech on 08/26/2015 12:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419647#msg1419647">Quote from: flux_capacitor on 08/25/2015 08:52 PM</a>
...

EDIT: Good Lord, when I wrote "toroidal" I really wanted to write poloidal field lines (around a torus shape) and not toroidal field lines (in the azimuthal direction, there is no magnetic field in that direction of course) :-X
I edited the drawing in my prior post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630).

I knew what you meant. What @Rodal calls azimuthal, I refer to as "circular", when the flux lines are circling the minor diameter, I call it "toroidal" like you did. The word "poloidal" was not in my vocabulary. :(
Thanks!
Todd

Sorry to get wonky, but let's discuss this further to agree on a common language to describe the complicated field distributons inside the truncated cone's EM Drive.

OK, to clarify this, I do agree that FluxCapacitor was correct that the word toroidal is a good description of the magnetic field as a solid, but with the magnetic field vectors oriented in the theta polar θ angle directionThe problem is that the word "torus" does not uniquely describe the direction of the magnetic vector field:  the magnetic vector field is not in the azimuthal φ direction of the surface of the torus, but instead it is directed in the polar θ direction, of the cross section of the torus, in the plane {θ,r}, with normal  φ


(StandardTori_701.gif)

There are no magnetic field vectors on the surface of the torus.  The magnetic field vectors are in cross-sectional cuts of the torus.

The problem with using @WarpTech's proposed word "circular" is that in spherical polar coordinates (which are the intrinsic coordinates to describe the spherical waves inside the truncated cone) there are two circular directions in spherical coordinates, hence "circular" does not uniquely describe what circular direction one is talking about:

the azimuthal angle  φ (phi)
the spherical polar angle, or "zenith angle" θ (theta)


(558px-3D_Spherical.svg.png)

(azimuth.gif)


https://en.wikipedia.org/wiki/Spherical_coordinate_system

"Circular" uniquely describes a direction for a cylinder, but not for a spherical cone, because "circular" does not uniquely identify what circular direction one is describing, since both φ and θ describe circles in different directions. Hence the word "circular" can lead to confusion as to what one is talking about.

(CavityShape.gif)

(SphericalCone_1000.gif)

CONCLUSION: It appears that the only unique way to describe these vector components is to identify the vector component directions: whether they are in:

the azimuthal angle  φ (phi) direction
the spherical polar angle, or "zenith angle" θ (theta) direction
the spherical radial "r" direction

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: chucknorris101 on 08/26/2015 02:04 PM
Just a newbie but been following these threads closely - my thought on the  movement 'up' towards the large end which wasnt expected - potentially still thermal effects? The magnetron heats the air in the frustum, it vents through the mesh and is trapped like a hot air balloon under the solid top plate and flange. 

No idea if that volume of air could create that much force, but as long as there is area outside (or even inside?) the frustum on the top plate, it could be solved with a few holes to vent?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 02:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419825#msg1419825">Quote from: chucknorris101 on 08/26/2015 02:04 PM</a>
Just a newbie but been following these threads closely - my thought on the  movement 'up' towards the large end which wasnt expected - potentially still thermal effects? The magnetron heats the air in the frustum, it vents through the mesh and is trapped like a hot air balloon under the solid top plate and flange. 

No idea if that volume of air could create that much force, but as long as there is area outside (or even inside?) the frustum on the top plate, it could be solved with a few holes to vent?
Have put magnetron on top side and will look for similar effects in Flight Test #2 soon.

Found it interesting that if it were thermal, it didn't start sooner...only the last 1/3 or so of test. Mag should have been up to temperature within the first min or so of tests.

It my guess for its thermal, but more data is coming...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/26/2015 02:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419832#msg1419832">Quote from: rfmwguy on 08/26/2015 02:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419825#msg1419825">Quote from: chucknorris101 on 08/26/2015 02:04 PM</a>
Just a newbie but been following these threads closely - my thought on the  movement 'up' towards the large end which wasnt expected - potentially still thermal effects? The magnetron heats the air in the frustum, it vents through the mesh and is trapped like a hot air balloon under the solid top plate and flange. 

No idea if that volume of air could create that much force, but as long as there is area outside (or even inside?) the frustum on the top plate, it could be solved with a few holes to vent?
Have put magnetron on top side and will look for similar effects in Flight Test #2 soon.

Found it interesting that if it were thermal, it didn't start sooner...only the last 1/3 or so of test. Mag should have been up to temperature within the first min or so of tests.

It my guess for its thermal, but more data is coming...

It is interesting to note that the Meep/Wolfram-Mathematica predictions were of a force differential between the bases in the direction that was measured: pointing towards the big base (same direction as measured).  These predictions have been carefully documented in these threads.  Since the predicted force towards the big base is compensated by the force towards the small end from the lateral conical walls, the net overall force (vectorially adding the forces from the bases and the force from the lateral conical walls) should be very small. 

We are looking forward with most anticipation to the results with the magnetron located at the big base, since in that case  the Meep/Wolfram-Mathematica calculations predict a net force differential between the bases in the opposite direction: towards the small base, that canNOT be compensated by the force on the lateral conical walls, because the force on the lateral conical walls actually adds up since it is also directed towards the small base. Hence the prediction is that with the magnetron located at the big base there is a greater force pointing towards the small base

These calculated predictions have been carefully documented in these threads and time-stamped. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/26/2015 02:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419832#msg1419832">Quote from: rfmwguy on 08/26/2015 02:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419825#msg1419825">Quote from: chucknorris101 on 08/26/2015 02:04 PM</a>
Just a newbie but been following these threads closely - my thought on the  movement 'up' towards the large end which wasnt expected - potentially still thermal effects? The magnetron heats the air in the frustum, it vents through the mesh and is trapped like a hot air balloon under the solid top plate and flange. 

No idea if that volume of air could create that much force, but as long as there is area outside (or even inside?) the frustum on the top plate, it could be solved with a few holes to vent?
Have put magnetron on top side and will look for similar effects in Flight Test #2 soon.

Found it interesting that if it were thermal, it didn't start sooner...only the last 1/3 or so of test. Mag should have been up to temperature within the first min or so of tests.

It my guess for its thermal, but more data is coming...

Is there any way for you to guesstimate whether your cavity was resonating during the experiment with the magnetron on ?
Whether the Q was ~ 0 , ~1,000 or ~10,000 ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 03:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419835#msg1419835">Quote from: Rodal on 08/26/2015 02:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419832#msg1419832">Quote from: rfmwguy on 08/26/2015 02:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419825#msg1419825">Quote from: chucknorris101 on 08/26/2015 02:04 PM</a>
Just a newbie but been following these threads closely - my thought on the  movement 'up' towards the large end which wasnt expected - potentially still thermal effects? The magnetron heats the air in the frustum, it vents through the mesh and is trapped like a hot air balloon under the solid top plate and flange. 

No idea if that volume of air could create that much force, but as long as there is area outside (or even inside?) the frustum on the top plate, it could be solved with a few holes to vent?
Have put magnetron on top side and will look for similar effects in Flight Test #2 soon.

Found it interesting that if it were thermal, it didn't start sooner...only the last 1/3 or so of test. Mag should have been up to temperature within the first min or so of tests.

It my guess for its thermal, but more data is coming...

Is there any way for you to guesstimate whether your cavity was resonating during the experiment with the magnetron on ?
Whether the Q was ~ 0 , ~1,000 or ~10,000 ?
Wish I could. Without connectors, can't take it to my VNA pals just yet. If positive results from test #2, might slap an N connector with monopole on it. While its only going to give me return loss peaks, guess we could do the -3dB BW points like others have done (shudder).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/26/2015 03:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419838#msg1419838">Quote from: rfmwguy on 08/26/2015 03:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419835#msg1419835">Quote from: Rodal on 08/26/2015 02:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419832#msg1419832">Quote from: rfmwguy on 08/26/2015 02:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419825#msg1419825">Quote from: chucknorris101 on 08/26/2015 02:04 PM</a>
Just a newbie but been following these threads closely - my thought on the  movement 'up' towards the large end which wasnt expected - potentially still thermal effects? The magnetron heats the air in the frustum, it vents through the mesh and is trapped like a hot air balloon under the solid top plate and flange. 

No idea if that volume of air could create that much force, but as long as there is area outside (or even inside?) the frustum on the top plate, it could be solved with a few holes to vent?
Have put magnetron on top side and will look for similar effects in Flight Test #2 soon.

Found it interesting that if it were thermal, it didn't start sooner...only the last 1/3 or so of test. Mag should have been up to temperature within the first min or so of tests.

It my guess for its thermal, but more data is coming...

Is there any way for you to guesstimate whether your cavity was resonating during the experiment with the magnetron on ?
Whether the Q was ~ 0 , ~1,000 or ~10,000 ?
Wish I could. Without connectors, can't take it to my VNA pals just yet. If positive results from test #2, might slap an N connector with monopole on it. While its only going to give me return loss peaks, guess we could do the -3dB BW points like others have done (shudder).

It is fascinating how all the stars have aligned perfectly for your next radio show, as hopefully you will have the two tests accomplished by the time of your next show :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 03:14 PM
One thing I noticed during testing is the transformer certainly kicks in with a loud hum, reminding me of a stuck electric motor. I read somewhere that this can induce a torsional movement, or at least vibration.

Think other builders need to be wary of this, especially if no liquid metal (isolation) is being used. The forces we are trying to measure are so small, air currents can disrupt tests, not to mention vibrations or movement transmitted along hard-wired setups.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/26/2015 03:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419770#msg1419770">Quote from: teitur on 08/26/2015 07:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419695#msg1419695">Quote from: rfmwguy on 08/26/2015 12:12 AM</a>
When I designed NSF-1701, I built it to be reconfigurable.

So I did just that...Doc, here's the new setup with the magnetron centered on the big base as you recommended. Its all ready for a second flight test!

But, its been a big day and I need a break form the shop. I'll test it again in a couple of days.

A heartfelt thanks for all the support!

I simple optical trick that may improve the sharpness of the laser dot in the movie is to move the camera back as far as possible and then to use the zoom (I hope your camera has one). This will make the paper with the laser dot sharper when you focus on the rig.

When you use a zoom lens things not on the plane of focus become blurrier.  A shallow depth of the field looks like, say, a picture in sport illustrated where the guy is in focus and the background is a bunch of circles and blobs.  I'd think the best way to improve sharpness on the laser would be multiple cameras, with one solely on the target and some way to create a visible mark (for example if both cameras showed the laser, you could pass your hand in front of the beam to mark the time).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/26/2015 03:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419838#msg1419838">Quote from: rfmwguy on 08/26/2015 03:08 PM</a>
Wish I could. Without connectors, can't take it to my VNA pals just yet. If positive results from test #2, might slap an N connector with monopole on it. While its only going to give me return loss peaks, guess we could do the -3dB BW points like others have done (shudder).

Well that will at least give you a picture of the return loss resonant dip frequencies and the approx bandwidth / Q. At least then you are not flying blind and pumping Rf energy into a frustum you have no hard S11 data on.

Go on, be devil. Do it. Please record the S11 data scans and share. I suspect you may get a surprise.

For an antenna use a 1/4 wave stub and a loop like the one EW uses. As you sides are mesh can insulate the bottom of the antenna and stick it through the mesh at various places (simple to do with the 1/4 wave stub, bit more difficult with the EW loop but still doable) to test out how side wall insertion location and orientation change the max rtn loss dBs and resonant frequency. Doing this could really feed the MEEP team a lot of real world data.

If you built another antenna, like that on your magnetron, you could get a good idea of what sort of load your magnetron is working into.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 03:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419844#msg1419844">Quote from: TheTraveller on 08/26/2015 03:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419838#msg1419838">Quote from: rfmwguy on 08/26/2015 03:08 PM</a>
Wish I could. Without connectors, can't take it to my VNA pals just yet. If positive results from test #2, might slap an N connector with monopole on it. While its only going to give me return loss peaks, guess we could do the -3dB BW points like others have done (shudder).

Well that will at least give you a picture of the return loss resonant dip frequencies and the approx bandwidth / Q. At least then you are not flying blind and pumping Rf energy into a frustum you have no hard S11 data on.

Go on, be devil. Do it. Please record the S11 data scans and share. I suspect you may get a surprise.
No theory supports any particular resonance on return loss for a broad spectral signal source. The shape was based on your spreadsheet and nasa data, so I hardly say its flying blind.

I am just not convinced Q is part of the equation for force generation; at least I've not seen that. It is an arbitrary measure of frequency and amplitude performance. Useful only in my mind for source matching.

Let me know if you discover a force formula listing Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/26/2015 03:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419848#msg1419848">Quote from: rfmwguy on 08/26/2015 03:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419844#msg1419844">Quote from: TheTraveller on 08/26/2015 03:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419838#msg1419838">Quote from: rfmwguy on 08/26/2015 03:08 PM</a>
Wish I could. Without connectors, can't take it to my VNA pals just yet. If positive results from test #2, might slap an N connector with monopole on it. While its only going to give me return loss peaks, guess we could do the -3dB BW points like others have done (shudder).

Well that will at least give you a picture of the return loss resonant dip frequencies and the approx bandwidth / Q. At least then you are not flying blind and pumping Rf energy into a frustum you have no hard S11 data on.

Go on, be devil. Do it. Please record the S11 data scans and share. I suspect you may get a surprise.
No theory supports any particular resonance on return loss for a broad spectral signal source. The shape was based on your spreadsheet and nasa data, so I hardly say its flying blind.

I am just not convinced Q is part of the equation for force generation; at least I've not seen that. It is an arbitrary measure of frequency and amplitude performance. Useful only in my mind for source matching.

Let me know if you discover a force formula listing Q.

I updated my post. Please review.

Both Shawyer and Prof Yangs Force equations involve Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/26/2015 04:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419824#msg1419824">Quote from: Rodal on 08/26/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419698#msg1419698">Quote from: WarpTech on 08/26/2015 12:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419647#msg1419647">Quote from: flux_capacitor on 08/25/2015 08:52 PM</a>
...

EDIT: Good Lord, when I wrote "toroidal" I really wanted to write poloidal field lines (around a torus shape) and not toroidal field lines (in the azimuthal direction, there is no magnetic field in that direction of course) :-X
I edited the drawing in my prior post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630).

I knew what you meant. What @Rodal calls azimuthal, I refer to as "circular", when the flux lines are circling the minor diameter, I call it "toroidal" like you did. The word "poloidal" was not in my vocabulary. :(
Thanks!
Todd

Sorry to get wonky, but let's discuss this further to agree on a common language to describe the complicated field distributons inside the truncated cone's EM Drive.

OK, to clarify this, I do agree that FluxCapacitor was correct that the word toroidal is a good description of the magnetic field as a solid, but with the magnetic field vectors oriented in the theta polar θ angle directionThe problem is that the word "torus" does not uniquely describe the direction of the magnetic vector field:  the magnetic vector field is not in the azimuthal φ direction of the surface of the torus, but instead it is directed in the polar θ direction, of the cross section of the torus, in the plane {θ,r}, with normal  φ


(StandardTori_701.gif)

There are no magnetic field vectors on the surface of the torus.  The magnetic field vectors are in cross-sectional cuts of the torus.

The problem with using @WarpTech's proposed word "circular" is that in spherical polar coordinates (which are the intrinsic coordinates to describe the spherical waves inside the truncated cone) there are two circular directions in spherical coordinates, hence "circular" does not uniquely describe what circular direction one is talking about:

the azimuthal angle  φ (phi)
the spherical polar angle, or "zenith angle" θ (theta)


(558px-3D_Spherical.svg.png)

(azimuth.gif)


https://en.wikipedia.org/wiki/Spherical_coordinate_system

"Circular" uniquely describes a direction for a cylinder, but not for a spherical cone, because "circular" does not uniquely identify what circular direction one is describing, since both φ and θ describe circles in different directions. Hence the word "circular" can lead to confusion as to what one is talking about.

(CavityShape.gif)

(SphericalCone_1000.gif)

CONCLUSION: It appears that the only unique way to describe these vector components is to identify the vector component directions: whether they are in:

the azimuthal angle  φ (phi) direction
the spherical polar angle, or "zenith angle" θ (theta) direction
the spherical radial "r" direction



The problem is not one of definition, it is vocabulary. It is obvious to me what you are saying, but in my vocabulary, the phi direction is around the major diameter and the theta direction is around the minor diameter. I have always referred to the theta direction as "toroidal". The phi direction is cylindrical or circular. It's just how I learned it.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/26/2015 04:52 PM
Just some random thought after a nights reflection:

Because of the ease or configuration and seemingly positive test result, I think rmfguy's mesh setup just became one of the preferred research setups for future test.

I think the idea that nothing will happen with the feed near the small base is not looking good.  Fortunately rmfguy's setup seems perfect for a series of tests comparing feeds at the small and large base as well as mesh and solid endplates. 

I'm seeing multiple indications that force builds up relatively slowly over time.  I'm afraid to say it, but I think we might need some meep runs showing what is going at least until projected force stops increasing with time (which might be several minutes in realtime).  Can we get an estimate about how much computing power we're talking about here?  Is this supercomputer range stuff?  I've got a Linux box with ok specs (but in need of a bigger hard drive) that I could donate to the cause for a month.  I suspect the computing requirements are somewhere far north of a desktop system.   

If it weren't for inertia on the beam, I'd say these results indicate that the point of maximum efficiency differs from the point of maximum power.   

I wonder if one of the laser rangerfinders used in golf (about $20) or hunting (about $150) would provide a better beam than the current laser pointer.

Speaking of mirrors, somebody mentions cannibalizing an old film SLR for a better mirror.  I should add that a larger mirror might be available from one of the Pentax medium format SLRs.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 05:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419850#msg1419850">Quote from: TheTraveller on 08/26/2015 03:53 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419848#msg1419848">Quote from: rfmwguy on 08/26/2015 03:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419844#msg1419844">Quote from: TheTraveller on 08/26/2015 03:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419838#msg1419838">Quote from: rfmwguy on 08/26/2015 03:08 PM</a>
Wish I could. Without connectors, can't take it to my VNA pals just yet. If positive results from test #2, might slap an N connector with monopole on it. While its only going to give me return loss peaks, guess we could do the -3dB BW points like others have done (shudder).

Well that will at least give you a picture of the return loss resonant dip frequencies and the approx bandwidth / Q. At least then you are not flying blind and pumping Rf energy into a frustum you have no hard S11 data on.

Go on, be devil. Do it. Please record the S11 data scans and share. I suspect you may get a surprise.
No theory supports any particular resonance on return loss for a broad spectral signal source. The shape was based on your spreadsheet and nasa data, so I hardly say its flying blind.

I am just not convinced Q is part of the equation for force generation; at least I've not seen that. It is an arbitrary measure of frequency and amplitude performance. Useful only in my mind for source matching.

Let me know if you discover a force formula listing Q.

I updated my post. Please review.

Both Shawyer and Prof Yangs Force equations involve Q.
Yet, each measure Q differently...see my point?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 08/26/2015 05:58 PM
@rfmwguy, it seems like many people are saying that the movement of the laser dot should be interpreted as a thrust signal and therefore the test should in fact be considered positive as opposed to null [1]

In your opinion, is the test result null or positive (or indeterminate)?  Are you standing by your previous statement that the test result was null?

[1] - Ignoring the fact that the laser moves in the wrong direction and the beam displays an unusual dynamic, where deflection seems to grow at a constant rate over the course of power on.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/26/2015 06:34 PM
RFMWGUY - great work, even better reporting :)
Two simple suggestions on the laser pointer that hopefully won't break the bank:
1) use a first-surface mirror, not one that's silvered on the back of the glass.  Check with a local glass/mirror supply house, jewelry shops use them in displays sometimes so a small piece like you need may be cheap.
2) try the pin-hole card trick (I don't think you did this already?) which should clean up the spot itself.

Seems like what you really want for the liquid current transfer mechanism is mercury...

Edit: O $hit. I just remembered I have a 5mw HeNe laser - WAY better spot definition than what you have.  But it would need 120v power...  I will gladly loan this to the cause if there's any way it would be helpful.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 06:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419877#msg1419877">Quote from: wallofwolfstreet on 08/26/2015 05:58 PM</a>
@rfmwguy, it seems like many people are saying that the movement of the laser dot should be interpreted as a thrust signal and therefore the test should in fact be considered positive as opposed to null [1]

In your opinion, is the test result null or positive (or indeterminate)?  Are you standing by your previous statement that the test result was null?

[1] - Ignoring the fact that the laser moves in the wrong direction and the beam displays an unusual dynamic, where deflection seems to grow at a constant rate over the course of power on.
Wolfy, one thing I learned is not to judge too quickly on results for such a small measurement. I had not gone to the great effort of clipping the laser out and putting it into a time line.

That being said, I personally think thermal is a likely cause, what confuses me a bit about this hypothesis is thermal effects should have shown up alot sooner than the last 1/3 of the video as the mag comes up to temp rather quickly. There are no other variable that make sense to me other than an Electromagnetic Engine effect that somehow grows over a 5 minute timeline.

If that is the case, we'll have to look at this as more than an instantaneous burst of motion.

As a side note, when I came back near the experiment at the end of the test run, I felt no warmer air than when I started, but did notice an unusual "ambience'" to the air. Best way I can describe it as metallic, ionized air. This is not scientific obviously, just a minor observation I did not notice during static testing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 06:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419882#msg1419882">Quote from: VAXHeadroom on 08/26/2015 06:34 PM</a>
RFMWGUY - great work, even better reporting :)
Two simple suggestions on the laser pointer that hopefully won't break the bank:
1) use a first-surface mirror, not one that's silvered on the back of the glass.  Check with a local glass/mirror supply house, jewelry shops use them in displays sometimes so a small piece like you need may be cheap.
2) try the pin-hole card trick (I don't think you did this already?) which should clean up the spot itself.

Seems like what you really want for the liquid current transfer mechanism is mercury...

Edit: O $hit. I just remembered I have a 5mw HeNe laser - WAY better spot definition than what you have.  But it would need 120v power...  I will gladly loan this to the cause if there's any way it would be helpful.
Appreciate it, guess I could use the static laser firing on a moving mirror. Let me get back with you on that...after flight test #2. Did the pinhole trick, simply attenuated the output. Its a cheapo laser pointer with no focusing capability, but its super lightweight. Thanks for the mirror heads-up. I'd love to get one locally.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/26/2015 07:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419888#msg1419888">Quote from: rfmwguy on 08/26/2015 06:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419882#msg1419882">Quote from: VAXHeadroom on 08/26/2015 06:34 PM</a>
RFMWGUY - great work, even better reporting :)
Two simple suggestions on the laser pointer that hopefully won't break the bank:
1) use a first-surface mirror, not one that's silvered on the back of the glass.  Check with a local glass/mirror supply house, jewelry shops use them in displays sometimes so a small piece like you need may be cheap.
2) try the pin-hole card trick (I don't think you did this already?) which should clean up the spot itself.

Seems like what you really want for the liquid current transfer mechanism is mercury...

Edit: O $hit. I just remembered I have a 5mw HeNe laser - WAY better spot definition than what you have.  But it would need 120v power...  I will gladly loan this to the cause if there's any way it would be helpful.
Appreciate it, guess I could use the static laser firing on a moving mirror. Let me get back with you on that...after flight test #2. Did the pinhole trick, simply attenuated the output. Its a cheapo laser pointer with no focusing capability, but its super lightweight. Thanks for the mirror heads-up. I'd love to get one locally.
I just ordered 2 under 8 bucks with shipping.
American Science & Surplus
MIRROR, FIRST SURFACE/39MM X 97MM X 3MM THK
Item Number: 31016P1
Quantity: 2

Back to the shop...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/26/2015 07:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419895#msg1419895">Quote from: SeeShells on 08/26/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419888#msg1419888">Quote from: rfmwguy on 08/26/2015 06:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419882#msg1419882">Quote from: VAXHeadroom on 08/26/2015 06:34 PM</a>
RFMWGUY - great work, even better reporting :)
Two simple suggestions on the laser pointer that hopefully won't break the bank:
1) use a first-surface mirror, not one that's silvered on the back of the glass.  Check with a local glass/mirror supply house, jewelry shops use them in displays sometimes so a small piece like you need may be cheap.
2) try the pin-hole card trick (I don't think you did this already?) which should clean up the spot itself.

Seems like what you really want for the liquid current transfer mechanism is mercury...

Edit: O $hit. I just remembered I have a 5mw HeNe laser - WAY better spot definition than what you have.  But it would need 120v power...  I will gladly loan this to the cause if there's any way it would be helpful.
Appreciate it, guess I could use the static laser firing on a moving mirror. Let me get back with you on that...after flight test #2. Did the pinhole trick, simply attenuated the output. Its a cheapo laser pointer with no focusing capability, but its super lightweight. Thanks for the mirror heads-up. I'd love to get one locally.
I just ordered 2 under 8 bucks with shipping.
American Science & Surplus
MIRROR, FIRST SURFACE/39MM X 97MM X 3MM THK
Item Number: 31016P1
Quantity: 2

Back to the shop...

Love that store.  They always had the FUNNEST catalogs with the craziest stuff!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/26/2015 07:26 PM

from wikipedia -
Quote
Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact.[1] The term is a portmanteau of the term "static friction",[2] perhaps also influenced by the verb "stick".

Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force.

In situations where two surfaces with areas below the micrometer range come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.

@rfmwguy - You mentioned transformer vibration. I wonder if a vibrator attached near the knife edges would help reduce stiction without causing worse problems elsewhere? Or would it cause the weight to cut into the edges. And is there any indication of knife edge wear at the point of contact?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/26/2015 07:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419902#msg1419902">Quote from: aero on 08/26/2015 07:26 PM</a>
from wikipedia -
Quote
Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact.[1] The term is a portmanteau of the term "static friction",[2] perhaps also influenced by the verb "stick".

Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force.

In situations where two surfaces with areas below the micrometer range come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.

@rfmwguy - You mentioned transformer vibration. I wonder if a vibrator attached near the knife edges would help reduce stiction without causing worse problems elsewhere? Or would it cause the weight to cut into the edges. And is there any indication of knife edge wear at the point of contact?

You would be better off if you used the backside of a old stainless steel butter knife with a rounded edge for the bottom. Rolling on a curved surface is better than the knife edges. My first tests with weights I chipped the edges of the blades when they were together like yours.

sorry back to the shop... again.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 07:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419902#msg1419902">Quote from: aero on 08/26/2015 07:26 PM</a>
from wikipedia -
Quote
Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact.[1] The term is a portmanteau of the term "static friction",[2] perhaps also influenced by the verb "stick".

Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force.

In situations where two surfaces with areas below the micrometer range come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.

@rfmwguy - You mentioned transformer vibration. I wonder if a vibrator attached near the knife edges would help reduce stiction without causing worse problems elsewhere? Or would it cause the weight to cut into the edges. And is there any indication of knife edge wear at the point of contact?
Good news is before the test, I lifted and slightly moved the fulcrum to an unused part of the blades. Realize I can only do this so often, but really haven't seen any gouging. I did get the more expensive blades. Have 2 more unused!
I have doubts about static/stiction since the contact surface is so small and the wood beam itself is not likely to store or transfer a static charge as a plastic or composite might. With more surface area in contact, a ball-bearing assembly might be more prone to this than a knife-edge, not sure.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/26/2015 08:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419907#msg1419907">Quote from: rfmwguy on 08/26/2015 07:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419902#msg1419902">Quote from: aero on 08/26/2015 07:26 PM</a>
from wikipedia -
Quote
Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact.[1] The term is a portmanteau of the term "static friction",[2] perhaps also influenced by the verb "stick".

Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force.

In situations where two surfaces with areas below the micrometer range come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.

@rfmwguy - You mentioned transformer vibration. I wonder if a vibrator attached near the knife edges would help reduce stiction without causing worse problems elsewhere? Or would it cause the weight to cut into the edges. And is there any indication of knife edge wear at the point of contact?
Good news is before the test, I lifted and slightly moved the fulcrum to an unused part of the blades. Realize I can only do this so often, but really haven't seen any gouging. I did get the more expensive blades. Have 2 more unused!
I have doubts about static/stiction since the contact surface is so small and the wood beam itself is not likely to store or transfer a static charge as a plastic or composite might. With more surface area in contact, a ball-bearing assembly might be more prone to this than a knife-edge, not sure.

Rmfguy, what is your opinion as to why the beam did not return back?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/26/2015 08:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419907#msg1419907">Quote from: rfmwguy on 08/26/2015 07:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419902#msg1419902">Quote from: aero on 08/26/2015 07:26 PM</a>
from wikipedia -
Quote
Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact.[1] The term is a portmanteau of the term "static friction",[2] perhaps also influenced by the verb "stick".

Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force.

In situations where two surfaces with areas below the micrometer range come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.

@rfmwguy - You mentioned transformer vibration. I wonder if a vibrator attached near the knife edges would help reduce stiction without causing worse problems elsewhere? Or would it cause the weight to cut into the edges. And is there any indication of knife edge wear at the point of contact?
Good news is before the test, I lifted and slightly moved the fulcrum to an unused part of the blades. Realize I can only do this so often, but really haven't seen any gouging. I did get the more expensive blades. Have 2 more unused!
I have doubts about static/stiction since the contact surface is so small and the wood beam itself is not likely to store or transfer a static charge as a plastic or composite might. With more surface area in contact, a ball-bearing assembly might be more prone to this than a knife-edge, not sure.
Figure it out :) i mean try it.
(The blades you are using is also a good choice i think)

BTW professional measurements what you are doing! Not sure about the result since the hot air from the magnetron could be able to lift the frustum (lower plate...).
Good luck and look forward to the next test!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/26/2015 08:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419870#msg1419870">Quote from: SteveD on 08/26/2015 04:52 PM</a>
Just some random thought after a nights reflection:

Because of the ease or configuration and seemingly positive test result, I think rmfguy's mesh setup just became one of the preferred research setups for future test.

I think the idea that nothing will happen with the feed near the small base is not looking good.  Fortunately rmfguy's setup seems perfect for a series of tests comparing feeds at the small and large base as well as mesh and solid endplates. 

I'm seeing multiple indications that force builds up relatively slowly over time.  I'm afraid to say it, but I think we might need some meep runs showing what is going at least until projected force stops increasing with time (which might be several minutes in realtime).  Can we get an estimate about how much computing power we're talking about here?  Is this supercomputer range stuff?  I've got a Linux box with ok specs (but in need of a bigger hard drive) that I could donate to the cause for a month.  I suspect the computing requirements are somewhere far north of a desktop system.   

If it weren't for inertia on the beam, I'd say these results indicate that the point of maximum efficiency differs from the point of maximum power.   

I wonder if one of the laser rangerfinders used in golf (about $20) or hunting (about $150) would provide a better beam than the current laser pointer.

Speaking of mirrors, somebody mentions cannibalizing an old film SLR for a better mirror.  I should add that a larger mirror might be available from one of the Pentax medium format SLRs.

Quarter-wave front surface 50mm flat for $85.   That's telescope quality.

http://www.edmundoptics.com/optics/optical-mirrors/flat-mirrors/quarter-wave-first-surface-mirrors/45607/

Edit: I see Shell's (by the seashore) found you a cheaper one.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/26/2015 08:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419859#msg1419859">Quote from: WarpTech on 08/26/2015 04:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419824#msg1419824">Quote from: Rodal on 08/26/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419698#msg1419698">Quote from: WarpTech on 08/26/2015 12:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419647#msg1419647">Quote from: flux_capacitor on 08/25/2015 08:52 PM</a>
...

EDIT: Good Lord, when I wrote "toroidal" I really wanted to write poloidal field lines (around a torus shape) and not toroidal field lines (in the azimuthal direction, there is no magnetic field in that direction of course) :-X
I edited the drawing in my prior post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419630#msg1419630).

I knew what you meant. What @Rodal calls azimuthal, I refer to as "circular", when the flux lines are circling the minor diameter, I call it "toroidal" like you did. The word "poloidal" was not in my vocabulary. :(
Thanks!
Todd

Sorry to get wonky, but let's discuss this further to agree on a common language to describe the complicated field distributons inside the truncated cone's EM Drive.

OK, to clarify this, I do agree that FluxCapacitor was correct that the word toroidal is a good description of the magnetic field as a solid, but with the magnetic field vectors oriented in the theta polar θ angle directionThe problem is that the word "torus" does not uniquely describe the direction of the magnetic vector field:  the magnetic vector field is not in the azimuthal φ direction of the surface of the torus, but instead it is directed in the polar θ direction, of the cross section of the torus, in the plane {θ,r}, with normal  φ


(StandardTori_701.gif)

There are no magnetic field vectors on the surface of the torus.  The magnetic field vectors are in cross-sectional cuts of the torus.

The problem with using @WarpTech's proposed word "circular" is that in spherical polar coordinates (which are the intrinsic coordinates to describe the spherical waves inside the truncated cone) there are two circular directions in spherical coordinates, hence "circular" does not uniquely describe what circular direction one is talking about:

the azimuthal angle  φ (phi)
the spherical polar angle, or "zenith angle" θ (theta)


(558px-3D_Spherical.svg.png)

(azimuth.gif)


https://en.wikipedia.org/wiki/Spherical_coordinate_system

"Circular" uniquely describes a direction for a cylinder, but not for a spherical cone, because "circular" does not uniquely identify what circular direction one is describing, since both φ and θ describe circles in different directions. Hence the word "circular" can lead to confusion as to what one is talking about.

(CavityShape.gif)

(SphericalCone_1000.gif)

CONCLUSION: It appears that the only unique way to describe these vector components is to identify the vector component directions: whether they are in:

the azimuthal angle  φ (phi) direction
the spherical polar angle, or "zenith angle" θ (theta) direction
the spherical radial "r" direction



The problem is not one of definition, it is vocabulary. It is obvious to me what you are saying, but in my vocabulary, the phi direction is around the major diameter and the theta direction is around the minor diameter. I have always referred to the theta direction as "toroidal". The phi direction is cylindrical or circular. It's just how I learned it.
Todd
Yes the choice of different coordinate systems can lead to miscommunication ::)

The problem is that all people thinking the way what they learned.
I also do thinking "circular" most time. ;D
But Rodal and you are right we have to define a precise vocabulary for the different coordinate systems, otherwise there will be misunderstandings again and again.

EDIT:The other way is to use sketches/pictures to get consistency...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cej on 08/26/2015 08:28 PM
Since this was brought up again, I've created an entry on the emdrive wiki to explain the different Q value techniques here (http://emdrive.wiki/Q_Factor). Disclaimer: I know nothing about Q factors and am only working from what has been said in this thread. Please make corrections directly to the wiki (or else PM me) so we can minimize the noise here. We should also update the experimental results wiki to specify the method used to measure Q.

The new entry also has a "discussion" page where future arguments about the merits of each technique could take place...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/26/2015 08:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419913#msg1419913">Quote from: demofsky on 08/26/2015 08:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419907#msg1419907">Quote from: rfmwguy on 08/26/2015 07:42 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419902#msg1419902">Quote from: aero on 08/26/2015 07:26 PM</a>
from wikipedia -
Quote
Stiction is the static friction that needs to be overcome to enable relative motion of stationary objects in contact.[1] The term is a portmanteau of the term "static friction",[2] perhaps also influenced by the verb "stick".

Any solid objects pressing against each other (but not sliding) will require some threshold of force parallel to the surface of contact in order to overcome static cohesion. Stiction is a threshold, not a continuous force.

In situations where two surfaces with areas below the micrometer range come into close proximity (as in an accelerometer), they may adhere together. At this scale, electrostatic and/or Van der Waals and hydrogen bonding forces become significant. The phenomenon of two such surfaces being adhered together in this manner is also called stiction. Stiction may be related to hydrogen bonding or residual contamination.

@rfmwguy - You mentioned transformer vibration. I wonder if a vibrator attached near the knife edges would help reduce stiction without causing worse problems elsewhere? Or would it cause the weight to cut into the edges. And is there any indication of knife edge wear at the point of contact?
Good news is before the test, I lifted and slightly moved the fulcrum to an unused part of the blades. Realize I can only do this so often, but really haven't seen any gouging. I did get the more expensive blades. Have 2 more unused!
I have doubts about static/stiction since the contact surface is so small and the wood beam itself is not likely to store or transfer a static charge as a plastic or composite might. With more surface area in contact, a ball-bearing assembly might be more prone to this than a knife-edge, not sure.

Rmfguy, what is your opinion as to why the beam did not return back?
Likely because I moved the camera immediately after end of last 1 minute full power test. I won't do that next time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/26/2015 08:59 PM
http://www.jpier.org/PIERM/pierm05/02.08100704.pdf
Q factor
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/26/2015 09:02 PM
http://arxiv.org/abs/quant-ph/0603073

About berry phases and forces.

Following the article, the slow classical part will be the cavity, the fast quantum part  will be the electromagnetic fields modes in cavity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/26/2015 10:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419934#msg1419934">Quote from: Ricvil on 08/26/2015 09:02 PM</a>
http://arxiv.org/abs/quant-ph/0603073

About berry phases and forces.

Following the article, the slow classical part will be the cavity, the fast quantum part  will be the electromagnetic fields modes in cavity.

The Aharonov-Bohm effect (that Todd "WarpTech" discussed in his posts) can be interpreted as a geometrical phase factor of the kind postulated by Berry. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/26/2015 11:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419946#msg1419946">Quote from: Rodal on 08/26/2015 10:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419934#msg1419934">Quote from: Ricvil on 08/26/2015 09:02 PM</a>
http://arxiv.org/abs/quant-ph/0603073

About berry phases and forces.

Following the article, the slow classical part will be the cavity, the fast quantum part  will be the electromagnetic fields modes in cavity.

The Aharonov-Bohm effect (that Todd "WarpTech" discussed in his posts) can be interpreted as a geometrical phase factor of the kind postulated by Berry.
The only Plank I see around here is rfmwguy's floobie-stick  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 12:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419951#msg1419951">Quote from: deltaMass on 08/26/2015 11:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419946#msg1419946">Quote from: Rodal on 08/26/2015 10:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419934#msg1419934">Quote from: Ricvil on 08/26/2015 09:02 PM</a>
http://arxiv.org/abs/quant-ph/0603073

About berry phases and forces.

Following the article, the slow classical part will be the cavity, the fast quantum part  will be the electromagnetic fields modes in cavity.

The Aharonov-Bohm effect (that Todd "WarpTech" discussed in his posts) can be interpreted as a geometrical phase factor of the kind postulated by Berry.
The only Plank I see around here is rfmwguy's floobie-stick  8)
LOL...I knew I forgot something...I was going to write that on the beam  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/27/2015 12:55 AM

http://arxiv.org/pdf/physics/0611024

Better?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419951#msg1419951">Quote from: deltaMass on 08/26/2015 11:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419946#msg1419946">Quote from: Rodal on 08/26/2015 10:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419934#msg1419934">Quote from: Ricvil on 08/26/2015 09:02 PM</a>
http://arxiv.org/abs/quant-ph/0603073

About berry phases and forces.

Following the article, the slow classical part will be the cavity, the fast quantum part  will be the electromagnetic fields modes in cavity.

The Aharonov-Bohm effect (that Todd "WarpTech" discussed in his posts) can be interpreted as a geometrical phase factor of the kind postulated by Berry.
The only Plank I see around here is rfmwguy's floobie-stick  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 01:59 AM
SURPRISE! Here is the just completed and unedited video of NSF-1701 Flight Test #2. I'll be watching it with you...

https://youtu.be/P3_XtcjinRs

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cosmo on 08/27/2015 02:10 AM
@rfmwguy - Newbie poster here.  Followed all the threads and have a suggestion.  From an experimental standpoint, it would be useful to collect multiple data sets (in your case, the 10 min video of the laser dot position), with the same configuration. Put simply, run the test 3 separate times, with a delay (an hour or two) between runs.  Then post the 3 videos. This would allow those evaluating the data to see if there are repeatable patterns.  If the results are not consistent, it raises questions about the experimental setup and conditions.  Once a particular configuration has been torn down and reconfigured, it's non-trivial to recreate it exactly for verification purposes.
Please keep up the excellent work!
Kurt
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 08/27/2015 02:16 AM
On the topic of testing methodology, being able to turn the magnetron on and off from the other room seems like it could help get tighter control over air currents. Keep up the good work, rfmwguy!  :D
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 02:19 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419980#msg1419980">Quote from: cosmo on 08/27/2015 02:10 AM</a>
@rfmwguy - Newbie poster here.  Followed all the threads and have a suggestion.  From an experimental standpoint, it would be useful to collect multiple data sets (in your case, the 10 min video of the laser dot position). Put simply, run the test 3 separate times, with a delay (an hour or two) between runs.  Then post the 3 videos. This would allow those evaluating the data to see if there are repeatable patterns.  Once a particular configuration has been torn down and reconfigured, it's non-trivial to recreate it exactly for verification purposes.
Please keep up the excellent work!
Kurt
Thanks, my first view of the vid appears to show something happening that wasn't there yesterday. If so, you bet I will start tweaking the setup, such as a new mirror, camera, target and who knows what else besides a longer static recording time. If movement confirmed, I'll not modify NSF-1701 from its current configuration.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sherman on 08/27/2015 02:22 AM
It seems to me the laser is a lot less settled in this test. I don't know enough about when/where to take the screenshots, so I will not do so here.

Let's hope [EDIT: Croppa] can provide us with a similar analysis as before. I believe that is far more useful compared to what I could provide.

Good Work!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 08/27/2015 02:26 AM
After the oscillations from starting the tests settle down, the laser is pointing lower on the target. I guess that would be the new 'zero' for each test. From there, I don't see any movement.

Of course, my technique of placing sticky notes on my monitor might not be the most accurate method.  :)

It's time for the data analysis group to zoom in and examine it frame by frame.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sherman on 08/27/2015 02:30 AM
Of course, if someone wants to give me a list of timestamps they would like to see side by side, I can do that.

Just not too many please!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/27/2015 02:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419982#msg1419982">Quote from: rfmwguy on 08/27/2015 02:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419980#msg1419980">Quote from: cosmo on 08/27/2015 02:10 AM</a>
@rfmwguy - Newbie poster here.  Followed all the threads and have a suggestion.  From an experimental standpoint, it would be useful to collect multiple data sets (in your case, the 10 min video of the laser dot position). Put simply, run the test 3 separate times, with a delay (an hour or two) between runs.  Then post the 3 videos. This would allow those evaluating the data to see if there are repeatable patterns.  Once a particular configuration has been torn down and reconfigured, it's non-trivial to recreate it exactly for verification purposes.
Please keep up the excellent work!
Kurt
Thanks, my first view of the vid appears to show something happening that wasn't there yesterday. If so, you bet I will start tweaking the setup, such as a new mirror, camera, target and who knows what else besides a longer static recording time. If movement confirmed, I'll not modify NSF-1701 from its current configuration.

Well done sir!
Could you please later  run another test, but with the cavity turned upside down?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 08/27/2015 02:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419730#msg1419730">Quote from: Croppa on 08/26/2015 02:49 AM</a>
Great work rfmwguy!

Here is a montage of how the region of interest looks throughout the whole movie (stretched in Y to make things clearer).

The microwave oven has a timer on it so it will be drawing mains power through a transformer even when the magnetron is not transmitting. Transformers give off a magnetic field. Was the oven powered up when the weight was used to calibrate the laser?

Alternative possibility. Static electricity can build up slowly.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cosmo on 08/27/2015 02:54 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419982#msg1419982">Quote from: rfmwguy on 08/27/2015 02:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419980#msg1419980">Quote from: cosmo on 08/27/2015 02:10 AM</a>
@rfmwguy - Newbie poster here.  Followed all the threads and have a suggestion.  From an experimental standpoint, it would be useful to collect multiple data sets (in your case, the 10 min video of the laser dot position). Put simply, run the test 3 separate times, with a delay (an hour or two) between runs.  Then post the 3 videos. This would allow those evaluating the data to see if there are repeatable patterns.  Once a particular configuration has been torn down and reconfigured, it's non-trivial to recreate it exactly for verification purposes.
Please keep up the excellent work!
Kurt
Thanks, my first view of the vid appears to show something happening that wasn't there yesterday. If so, you bet I will start tweaking the setup, such as a new mirror, camera, target and who knows what else besides a longer static recording time. If movement confirmed, I'll not modify NSF-1701 from its current configuration.

My thinking is that it would be very useful to compare 3 sets of the video data reduced as @Croppa did here:
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419750#msg1419750

If they don't correlate well for the same experimental configuration, then something is suspect.
Kurt

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/27/2015 03:04 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419984#msg1419984">Quote from: RonM on 08/27/2015 02:26 AM</a>
After the oscillations from starting the tests settle down, the laser is pointing lower on the target. I guess that would be the new 'zero' for each test. From there, I don't see any movement.

Of course, my technique of placing sticky notes on my monitor might not be the most accurate method.  :)

It's time for the data analysis group to zoom in and examine it frame by frame.
Indeed, also my observation. It's as if the floobiestick is permanently bent after a given trial. The obvious response to this is to call for more detailed calibration. There seems to be excess "stickiness" in the system.

Deflection direction  is the same as in test #1 (downward laser, upward frustum, therefore big-end-forward). There also seems to be a greater deflection with this new magnetron mount.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 08/27/2015 03:27 AM
Please include temps on big and little end walls as well as side walls, see if you can can a noticeable temp differential along the side and end walls.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 03:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419993#msg1419993">Quote from: deltaMass on 08/27/2015 03:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419984#msg1419984">Quote from: RonM on 08/27/2015 02:26 AM</a>
After the oscillations from starting the tests settle down, the laser is pointing lower on the target. I guess that would be the new 'zero' for each test. From there, I don't see any movement.

Of course, my technique of placing sticky notes on my monitor might not be the most accurate method.  :)

It's time for the data analysis group to zoom in and examine it frame by frame.
Indeed, also my observation. It's as if the floobiestick is permanently bent after a given trial. The obvious response to this is to call for more detailed calibration. There seems to be excess "stickiness" in the system.

Deflection direction  is the same as in test #1 (downward laser, upward frustum, therefore big-end-forward). There also seems to be a greater deflection with this new magnetron mount.
Once I see the video from croppa and others, I'll feel more confident in this configuration showing more movement. Only a guess, but the slow tracking downward is thermal lift even with mesh. If it tracks the same as yesterday, we have an answer. However, I did notice more movement overall this time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 03:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419988#msg1419988">Quote from: A_M_Swallow on 08/27/2015 02:48 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419730#msg1419730">Quote from: Croppa on 08/26/2015 02:49 AM</a>
Great work rfmwguy!

Here is a montage of how the region of interest looks throughout the whole movie (stretched in Y to make things clearer).

The microwave oven has a timer on it so it will be drawing mains power through a transformer even when the magnetron is not transmitting. Transformers give off a magnetic field. Was the oven powered up when the weight was used to calibrate the laser?

Alternative possibility. Static electricity can build up slowly.
Fields are small within the closed oven for the display, etc. Would be surprised it it impacted the small amount of magnetic material on the test stand. Static is possible, but we are over 50% RH so not likely to have an impact...all imo only.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 03:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419996#msg1419996">Quote from: cee on 08/27/2015 03:27 AM</a>
Please include temps on big and little end walls as well as side walls, see if you can can a noticeable temp differential along the side and end walls.
Only temp over ambient was on board where mag was mounted. Sides and bottom were near ambient in static thermal tests.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/27/2015 04:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419993#msg1419993">Quote from: deltaMass on 08/27/2015 03:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419984#msg1419984">Quote from: RonM on 08/27/2015 02:26 AM</a>
After the oscillations from starting the tests settle down, the laser is pointing lower on the target. I guess that would be the new 'zero' for each test. From there, I don't see any movement.

Of course, my technique of placing sticky notes on my monitor might not be the most accurate method.  :)

It's time for the data analysis group to zoom in and examine it frame by frame.
Indeed, also my observation. It's as if the floobiestick is permanently bent after a given trial. The obvious response to this is to call for more detailed calibration. There seems to be excess "stickiness" in the system.

Deflection direction  is the same as in test #1 (downward laser, upward frustum, therefore big-end-forward). There also seems to be a greater deflection with this new magnetron mount.

I just had a thought. In the past, I have weighed a HV capacitor charged and discharged, on a balance beam much smaller than this one. Regardless of polarity, when the capacitor is charged, it is heavier and the balance beam would tip.

Here, when the microwave is turned on, the frustum is charging with energy, like a capacitor. It's weight will increase due to the energy input to the system, M = E/c^2. When the frustum is charged, it's heavier. This is only a concern when using a balance beam. When using a rotary test setup, this is not an issue. However, like buoyancy, it can be subtracted off by turning it upside down but a mesh isn't going to prevent it.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 04:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419874#msg1419874">Quote from: rfmwguy on 08/26/2015 05:38 PM</a>
Yet, each measure Q differently...see my point?

As far as I know all EMDrive experimental data Q quotes are based on measured S11 rtn loss max dB then 3dB down bandwidth. While Prof Yang did theory work with a Q equation, she measured the frustum Q as above.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/27/2015 05:12 AM
Great job again rfmwguy  :)  I was actually still messing around with the file from yesterday. I took the audio from that movie and made a crude waveform with some free online software. I've highlighted the runs in green and you can see the periodical on/off of the magnetron within those runs.

Also here is the new run, treated exactly the same as before (0.25s/px). It's not likely I'll have chance to put landmarks in that one anytime soon but you can get a fair idea of time points from the laser gaps.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/27/2015 05:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420010#msg1420010">Quote from: WarpTech on 08/27/2015 04:02 AM</a>
I just had a thought. In the past, I have weighed a HV capacitor charged and discharged, on a balance beam much smaller than this one. Regardless of polarity, when the capacitor is charged, it is heavier and the balance beam would tip.

Here, when the microwave is turned on, the frustum is charging with energy, like a capacitor. It's weight will increase due to the energy input to the system, M = E/c^2. When the frustum is charged, it's heavier. This is only a concern when using a balance beam. When using a rotary test setup, this is not an issue. However, like buoyancy, it can be subtracted off by turning it upside down but a mesh isn't going to prevent it.
Todd
Sorry, but I'm calling nonsense on that lot, as a cursory calculation shows. Take a 2 mF capacitor charged to 10 kV. That's 100 kJ or a mass equivalent of 1 nanogram.. The fact that you did not have that precision but think you did illustrates how difficult is experimental physics, and how easily fooled even smart people can be.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 08/27/2015 05:46 AM
I wonder...

...didn't the Romanian report a similar effect in one of his tests?  A very slight 'bump' in an otherwise null result?

So...is this a bug?  Or a clue?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/27/2015 05:57 AM
Attached is my take on flight #2, audio aligned.

This is a 1 slice / second.

Some interesting oscillations are visible. The bump downwards was not during a run of the magnetron.

Not much going on during the low-power runs.

The most interesting thing I see is at the very beginning of the 100% test, there appears to be a slight initial bump upwards (the frustum moving downwards) that then slowly returns to baseline.

[Edit] Stretched the y-axis by 400%
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/27/2015 06:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420022#msg1420022">Quote from: deltaMass on 08/27/2015 05:28 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420010#msg1420010">Quote from: WarpTech on 08/27/2015 04:02 AM</a>
I just had a thought. In the past, I have weighed a HV capacitor charged and discharged, on a balance beam much smaller than this one. Regardless of polarity, when the capacitor is charged, it is heavier and the balance beam would tip.

Here, when the microwave is turned on, the frustum is charging with energy, like a capacitor. It's weight will increase due to the energy input to the system, M = E/c^2. When the frustum is charged, it's heavier. This is only a concern when using a balance beam. When using a rotary test setup, this is not an issue. However, like buoyancy, it can be subtracted off by turning it upside down but a mesh isn't going to prevent it.
Todd
Sorry, but I'm calling nonsense on that lot, as a cursory calculation shows. Take a 2 mF capacitor charged to 10 kV. That's 100 kJ or a mass equivalent of 1 nanogram.. The fact that you did not have that precision but think you did illustrates how difficult is experimental physics, and how easily fooled even smart people can be.

This was a ~2.5 mil piece of plexiglass, covered in aluminum foil, both sides, about 24" on a side. I had it balanced on a stick of balsa wood, connected to a rectified 12kV neon sign transformer. The result was repeatable. When on, the balance tipped toward the capacitor. I didn't actually measure a weight, just a deflection. It was tiny, but visible to the naked eye, and I wasn't using a laser and mirror to magnify the deflection. I just looked at the height above the table, with a ruler at the other end of the stick. The balsa wasn't more than 4' long.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/27/2015 06:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420034#msg1420034">Quote from: WarpTech on 08/27/2015 06:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420022#msg1420022">Quote from: deltaMass on 08/27/2015 05:28 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420010#msg1420010">Quote from: WarpTech on 08/27/2015 04:02 AM</a>
I just had a thought. In the past, I have weighed a HV capacitor charged and discharged, on a balance beam much smaller than this one. Regardless of polarity, when the capacitor is charged, it is heavier and the balance beam would tip.

Here, when the microwave is turned on, the frustum is charging with energy, like a capacitor. It's weight will increase due to the energy input to the system, M = E/c^2. When the frustum is charged, it's heavier. This is only a concern when using a balance beam. When using a rotary test setup, this is not an issue. However, like buoyancy, it can be subtracted off by turning it upside down but a mesh isn't going to prevent it.
Todd
Sorry, but I'm calling nonsense on that lot, as a cursory calculation shows. Take a 2 mF capacitor charged to 10 kV. That's 100 kJ or a mass equivalent of 1 nanogram.. The fact that you did not have that precision but think you did illustrates how difficult is experimental physics, and how easily fooled even smart people can be.

This was a ~2.5 mil piece of plexiglass, covered in aluminum foil, both sides, about 24" on a side. I had it balanced on a stick of balsa wood, connected to a rectified 12kV neon sign transformer. The result was repeatable. When on, the balance tipped toward the capacitor. I didn't actually measure a weight, just a deflection. It was tiny, but visible to the naked eye, and I wasn't using a laser and mirror to magnify the deflection. I just looked at the height above the table, with a ruler at the other end of the stick. The balsa wasn't more than 4' long.
Todd
What is wrong with you? You just made it about a hundred thousand times worse!
a) You have all these dimensions but can't be bothered to calculate the capacitance or the energy or the mass equivalent (don't worry, I did it for you and you are 105 down on my energy example)
b) You make no reference to the calculation I provided you before, nor to the back-of-the-envelope estimate that produced as a reference (as if I wrote nothing)
c) You don't use metric (yes, I know you're a USAn but that's a poor excuse).
d) You continue to insist that you measured a weight change even though it would have been one hundred thousandth of a nanogram!!!
e) It does not occur to you that you are measuring an artifact due most likely to static electricity (despite my warnings).

Really  :(

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/27/2015 07:10 AM
Looks like I'm a bit late to the party.  Please leave on the light so that we can see the rig next time.  For some reason you're camera picked up less ambient light this time (changing its exposure settings).  I object to drawing any conclusions to a light moving in a dark room where I can't see what is going on.

I see others have done the analysis better than I.  The final image is way too speculative.  Enough has changed in the setup that I lack confidence that the target and camera are in the same location.  That said, it looks like you ended almost exactly at the same point you did last time.  It might be a thermal effect but I don't think its lift from heated air.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/27/2015 08:27 AM
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/27/2015 09:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.
I definitely second that!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SlightPace on 08/27/2015 09:58 AM
Not to be too critical, but this thread is really strange sometimes. People put in so much time, effort, and money to build test rigs, but don't bother with any kind of proper scientific conduct when testing them.

@rfmwguy: you have a nice rig, but where is your control experiment? Your hypothesis is that a resonating truncated conical cavity produces thrust, but that is not what you are testing with your experiments so far. Controls should be:
A) Non-resonating cavity, e.g. put something in the cavity which interferes with the resonance, or put the magnetron outside of the cavity (with relevant safety measures of course)
B) Non-conical cavity

To start changing other variables before having a control experiment makes no sense at all. Since you don't even know if your cavity is resonating, right now you are just testing what happens to a balance beam when you fire off a magnetron nearby.
The control experiments is the absolute first things you should do.

Again, sorry if it comes across as too critical, but it is frustrating to see a such a nice experimental setup go to waste (like Iulian).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: bunjatec on 08/27/2015 11:58 AM
Hi, Another noob here lurking..  :)

Just saw this
http://phys.org/news/2015-08-theory-radiationless-revolution.html (http://phys.org/news/2015-08-theory-radiationless-revolution.html)

With the talk of poloidal fields this new theory seems relevant, hope it's useful..
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 08/27/2015 12:07 PM
Rmmfguy
Thanks for making those video available for public viewing
And on behalf of many here, we appreciate the time and sacrifice of effort that when into building the test rig and the ongoing testing.
Something that I noted  as an observation between the two tests during power ’on’ was a change in the 'audible humming tone"
NSF-1701 Flight Test #1 try listening between 4:50 to 5:00
NSF-1701 Flight Test #2 try listening between 4:41 to 4:51
On test 1 I can hear something sounding like a higher and harder metallic note.
On test 2 I can hear a slightly more lower quieter and softer and more even note.
Rough Analogy: It makes me think of arc welding steel as much as it’s a visual skill you learn It’s also a skill you learn naturally by using your ears.
 i.e. A high arc gap sounds bit like first test .[beginner's or start of weld] Second one sounds bit more like when arc gap and current  is getting dial in and laying down weld.
 It could mean that the big end plate was vibrating as a drum in first test run, and on the second run with magnetron’s end change it's now served a dual purpose  of stiffing up  the big end plate up. And stopping or damped down some low frequency audible resonance. Or some else of interest.
Suggestion:  why not  go the garage when all is quiet  and people have gone to bed and use you ears  [no need to video]  as see if you can track down the placement main source of the "hum"  It might just prove to be a helpful  observation….
You know there is some resemblance to a  “big speaker”   after all…
https://www.youtube.com/watch?v=aP_Z3s8Zas0


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: chucknorris101 on 08/27/2015 02:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.

I think rfmwguy's setup is actually perfect for the flip test as well - the flanges that may have caused trapping of hot air in this direction are symmetrical on the other side - so any buoyant effects should be the same (I imagine it might be different for just a solid frustum shape, one end up or the other, but im not a physicist)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 02:15 PM
Once again, thanks for all for analysis and commentary. I find it inspirational. I went to bed early last night after a couple of days of intense shop work and testing. Here are some thoughts this AM:

1) There is some unexpected movement that is worth pursuing at a higher measurement resolution; well below 200 mg.
2) FT1 and FT2 produces what I believe to be thermal lift as the magnetron goes through its 6 minute total  testing cycle, equivalent to approximately 500 mg.
3) The thermal lift is more linear in FT2. One possibility is the (heat source) magnetron is on the bottom of the assembly in FT1 and heated air builds, then surges upwards around the bottom plate. On top in FT2, it simply rises vertically, in a more controlled, semi-linear fashion.
4) Galinstan has an unexpectedly high amount of surface tension and high viscosity. Hat tip to Mr. Peter for pointing this out. On the positive side, this helps dampen oscillations. On the negative side, it attenuates small movements.
5) The panoramic mirror adds unecessary distortion in an attempt to create greater range of deflection.
6) The laser pointer mounted on the beam is not of a quality high enough for accurate readings in the milligram force range.
7) My mechanical test stand is suitable for further measurements with the following improvements:

a) High quality laser, tripod mounted off the beam, directed at a single surface, flat mirror mounted where the laser pointer is now on the balance beam.
b) Another single surface, flat mirror mounted on tripod where panoramic mirror is now located.
c) design a new laser target (have to think about this some more)
d) Replace galinstan with salt water per Mr. Peter's suggestion to lessen galistan drag.
e) HD video camera

Final notes: While I do not have the budget and time to spend creating a set of lab-quality experiments, I do believe DIY projects have something to offer to the body of knowledge, if not help stimulate interest in science. Private and public institutions exude secrecy, which can lead to wild speculation and unsubstantiated rumors. DIY projects can help reverse that trend and lead to more open-sourced projects we desperately need in many disciplines; the internet is a gift we should put to good use.

Pic Caption: FT2 setup this AM. Looking down with magnetron mounted on big base, small base is down. Electrodes dipping down into copper cups will Galinstan. Note location of black laser pointer.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/27/2015 02:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.
I agree that the next step should be to flip the truncated cone so that the opposite end is pointing up.

Concerning the power settings: it was a good idea for RFMWGUY to plan to test the power at different settings before we knew what the test results were going to be.  Why? Because the claimed results from Yang and Shawyer are by several orders of magnitude higher than those reported by Tajmar and by NASA. But now that we know that the results are at the very threshold of the measuring ability of this set-up, wouldn't it make sense to only test at 100% (maximum) power setting?

What is the point of testing at lower power setting when even the 100% maximum power setting gives results that are at the threshold of the measurement capability?

I would only test at 100% maximum power setting from now on.  I would conduct the same or more number of power on/ power off time settings. 
This would allow us to look at some statistical distribution, by only testing at 100% maximum power and having several tests power on/ power off/power on/power off.  Testing at only 100% power setting, and conducting a number of such tests would allow to further differentiate between the slow drift that appears unrelated to power, and any other movements.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/27/2015 02:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...1) There is some unexpected movement that is worth pursuing at a higher measurement resolution; well below 200 mg....
I agree.  Since the movement is at the threshold or below the threshold of what can be measured at the moment, I would only test at 100% power from now on.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...2) FT1 and FT2 produces what I believe to be thermal lift as the magnetron goes through its 6 minute total  testing cycle, equivalent to approximately 500 mg....

I completely agree.  The slow drift looks like a slow thermal artifact and not related to the electromagnetic power on/power off.  We need to distinguish between the slow drift that appears unrelated to the electromagnetic power and other movements that may not be so explained away.

////////////////////////////////////

I hope that you will continue with your experiments  :)

Congratulations again for a very impressive experiment ! 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/27/2015 02:31 PM
Are those carpenter's laser leveling systems from Home Depot or Lowes sharp enough for this sort of thing? I would assume they would be and they aren't that expensive and later you can use it for what it was made for. for example:  http://www.lowes.com/ProductDisplay?partNumber=587559-353-8203-CL&langId=-1&storeId=10151&productId=50285087&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1

and you can get models that project cross hairs/ cross lines instead of a dot with the ability to switch between dots and crossed perpendicular lines.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/27/2015 03:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420219#msg1420219">Quote from: Rodal on 08/27/2015 02:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.
I agree that the next step should be to flip the truncated cone so that the opposite end is pointing up.

Concerning the power settings: it was a good idea for RFMWGUY to plan to test the power at different settings before we knew what the test results were going to be.  Why? Because the claimed results from Yang and Shawyer are by several orders of magnitude higher than those reported by Tajmar and by NASA. But now that we know that the results are at the very threshold of the measuring ability of this set-up, wouldn't it make sense to only test at 100% (maximum) power setting?

What is the point of testing at lower power setting when even the 100% maximum power setting gives results that are at the threshold of the measurement capability?

I would only test at 100% maximum power setting from now on.  I would conduct the same or more number of power on/ power off time settings. 
This would allow us to look at some statistical distribution, by only testing at 100% maximum power and having several tests power on/ power off/power on/power off.  Testing at only 100% power setting, and conducting a number of such tests would allow to further differentiate between the slow drift that appears unrelated to power, and any other movements.

@rfmwguy - correct me if I am wrong, but I thought the magnetron had only 2 power settings, "off" and 100%. It is the microwave oven control that runs the magnetron at 100% power, but only 30% of the time achieving what is called 30% power level. And it is 30% for cooking, but for the thruster, it is 100% for 30% of the time.

And on a side note, why 30%, why not 50%? Have you been able to calculate the resonate frequency of your foobie stick set-up? It might be interesting if it is possible to drive your balance beam at resonance.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/27/2015 03:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420220#msg1420220">Quote from: Rodal on 08/27/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...1) There is some unexpected movement that is worth pursuing at a higher measurement resolution; well below 200 mg....
I agree.  Since the movement is at the threshold or below the threshold of what can be measured at the moment, I would only test at 100% power from now on.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...2) FT1 and FT2 produces what I believe to be thermal lift as the magnetron goes through its 6 minute total  testing cycle, equivalent to approximately 500 mg....

I completely agree.  The slow drift looks like a slow thermal artifact and not related to the electromagnetic power on/power off.  We need to distinguish between the slow drift that appears unrelated to the electromagnetic power and other movements that may not be so explained away.

////////////////////////////////////

I hope that you will continue with your experiments  :)

Congratulations again for a very impressive experiment !

It seems to me that the advantage of running at lower power is that it cycles on/off without rfmwguy being close to the setup. As I understand it the on cycles are full power anyway and only the overall proportion of on time is reduced. There are definite oscillations associated with the start of these runs (you can see these more easily in the unstretched montage shown here, as well as the raw video). I suspect these are air currents associated with rfmwguy moving past the apparatus after triggering the run but can't say for sure.

As other have noted, a great improvement to the current setup would be the ability to trigger it from a distance, although I imagine that's not trivial.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 03:46 PM
Dave,

Instead of guessing in the dark at what load your magnetron is driving and whether your frustum has resonance or not at the magnetron's freq output bandwidth, you need to make a magnetron antenna probe that matches your magnetron's antenna, as attached, put it where your magnetron's antenna is installed and do a VNA S11 return loss dB sweep. From that you will get the resonant frequencies and the VSWR / impedance match.

It bothers me that your frustum is not getting warm as the magnetron's output energy has to be heating something. Worst case is it is all getting rejected as there is no resonance, lousy VSWR and the high level of reflected Rf is heating your magnetron.

Doesn't matter that you think this is not the correct why to do this. You need to do a survey of your frustum's resonant frequencies. Eagleworks did it. You need to characterise your frustum so you know what you are dealing with and what sort of load your magnetron is driving.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/27/2015 03:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420228#msg1420228">Quote from: Croppa on 08/27/2015 03:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420220#msg1420220">Quote from: Rodal on 08/27/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...1) There is some unexpected movement that is worth pursuing at a higher measurement resolution; well below 200 mg....
I agree.  Since the movement is at the threshold or below the threshold of what can be measured at the moment, I would only test at 100% power from now on.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...2) FT1 and FT2 produces what I believe to be thermal lift as the magnetron goes through its 6 minute total  testing cycle, equivalent to approximately 500 mg....

I completely agree.  The slow drift looks like a slow thermal artifact and not related to the electromagnetic power on/power off.  We need to distinguish between the slow drift that appears unrelated to the electromagnetic power and other movements that may not be so explained away.

////////////////////////////////////

I hope that you will continue with your experiments  :)

Congratulations again for a very impressive experiment !

It seems to me that the advantage of running at lower power is that it cycles on/off without rfmwguy being close to the setup. As I understand it the on cycles are full power anyway and only the overall proportion of on time is reduced. There are definite oscillations associated with the start of these runs (you can see these more easily in the unstretched montage shown here, as well as the raw video). I suspect these are air currents associated with rfmwguy moving past the apparatus after triggering the run but can't say for sure.

As other have noted, a great improvement to the current setup would be the ability to trigger it from a distance, although I imagine that's not trivial.

Cycling on/off at less than 100% full power constantly on all the cycle time has this undeniable drawback:

 the response at the moment is so small that it is at the threshold or below the threshold of what can be measured.  Therefore one should only test with 100% power constantly on all the cycle time in order to try to maximize the response.  Anything less than 100% power on during the ON cycle will just result in amplifying the relative level of "noise" (thermal and other artifacts) and minimizing the relative level of any possible signal that is not an artifact.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kencolangelo on 08/27/2015 04:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420228#msg1420228">Quote from: Croppa on 08/27/2015 03:07 PM</a>
As other have noted, a great improvement to the current setup would be the ability to trigger it from a distance, although I imagine that's not trivial.
It should be really easy to trigger remotely. Ultimately the microwave control panel has a Start button, a membrane switch, you can just solder onto the circuit board and run two long wires wherever you like attached to a remote start momentary contact button. Preferably something dramatic. http://www.amazon.com/Lock-Switch-Mushroom-Button-Station/dp/B008ZY9CXE (http://www.amazon.com/Lock-Switch-Mushroom-Button-Station/dp/B008ZY9CXE).
This person found a microwave and replaced the pad entirely with a hack of their own.
http://hackaday.com/2011/06/09/repairing-a-broken-microwave-keypad/ (http://hackaday.com/2011/06/09/repairing-a-broken-microwave-keypad/)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Abyss on 08/27/2015 04:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420233#msg1420233">Quote from: TheTraveller on 08/27/2015 03:46 PM</a>
You need to do a survey of your frustum's resonant frequencies. Eagleworks did it. You need to characterise your frustum so you know what you are dealing with and what sort of load your magnetron is driving.

Agreed.  As more experiments are run it is clear that the 'magic' parameters for large measurable forces must be in a very small range.  (as an aside, to me that makes it questionable that Shawyer found them in the first place). 

As the search begins, it will be more and more important to characterize each step of the way to ensure you are working with what you think you are working with.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 05:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420245#msg1420245">Quote from: Abyss on 08/27/2015 04:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420233#msg1420233">Quote from: TheTraveller on 08/27/2015 03:46 PM</a>
You need to do a survey of your frustum's resonant frequencies. Eagleworks did it. You need to characterise your frustum so you know what you are dealing with and what sort of load your magnetron is driving.

Agreed.  As more experiments are run it is clear that the 'magic' parameters for large measurable forces must be in a very small range.  (as an aside, to me that makes it questionable that Shawyer found them in the first place). 

As the search begins, it will be more and more important to characterize each step of the way to ensure you are working with what you think you are working with.

Agreed.

Shawyer's 1st EMDrive, that he reported on, was highly tunable as attached.

So he clearly KNEW of the variables and designed in methods to deal with them, which says to me this was not his 1st experimental build but his 1st successful experimental build.

Shawyer did have at least a decade or 2 of microwave experience before he built his 1st device, so he had a decent real world microwave background knowledge to work from.

His Experimental unit could tune the top plate, the feed waveguide impedance, and the amount of the bottom dielectric insertion into the frustum for maximum Force generation. Says to me he knew well the devil he was working with. And this was in 2000 - 2002.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: seggybop on 08/27/2015 05:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
Pic Caption: FT2 setup this AM. Looking down with magnetron mounted on big base, small base is down. Electrodes dipping down into copper cups will Galinstan. Note location of black laser pointer.
Is that blue masking tape holding the laser pointer in place? If so, that will be really prone to slowly drooping.
I think it may be a good idea to affix it with something more rigid, like hose clamps.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 08/27/2015 05:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420252#msg1420252">Quote from: TheTraveller on 08/27/2015 05:09 PM</a>

Agreed.

Shawyer's 1st EMDrive, that he reported on, was highly tunable as attached.

So he clearly KNEW of the variables and designed in methods to deal with them, which says to me this was not his 1st experimental build but his 1st successful experimental build.

Shawyer did have at least a decade or 2 of microwave experience before he built his 1st device, so he had a decent real world microwave background knowledge to work from.

His Experimental unit could tune the top plate, the feed waveguide impedance, and the amount of the bottom dielectric insertion into the frustum for maximum Force generation. Says to me he knew well the devil he was working with. And this was in 2000 - 2002.

I agree. Shawyer's experience surely showed him that he needed to be able to tune the most parameters he could.

And he came with a solution that could tune the geometry (vital for achieving resonance or the "right stuff") and possibly the magnetron's frequency. In this way he just needed to build one test device for covering a big swath of combinations, instead of building one fixed model, seeing it didn't work well or at all, and then build another and another.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/27/2015 05:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419886#msg1419886">Quote from: rfmwguy on 08/26/2015 06:48 PM</a>

...

If that is the case, we'll have to look at this as more than an instantaneous burst of motion.

As a side note, when I came back near the experiment at the end of the test run, I felt no warmer air than when I started, but did notice an unusual "ambience'" to the air. Best way I can describe it as metallic, ionized air. This is not scientific obviously, just a minor observation I did not notice during static testing.

That metallic ionized air may be ozone.   If it collects under the flat metal pieces, due to static effects, it may have a bouyant force.    Because of the static attraction to the metal the ionized molecules will accumulate under the plate and that population will have a lower pressure because of similar charge repulsion.   The ionized air does not have to be physically contained to cause an upward force.   Maybe by interposing a grounded screen just under the metal plate this bouyant force will be removed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/27/2015 05:56 PM
rfmwguy -

I just spent some time trying to reconcile the results you have with some kind of expectation of how the setup should respond to a thrust.

The apparent slow movement of the balance beam seems simplest to fit to thermal (probably air current related) forces building as the temperature rises. That's also consistent with the apparent direction of the force being upwards in both cases. There could still be thrust, but thermal effects will clutter the results. What's more, I think that's intrinsic to the balance-beam approach, where the measured thrust is necessarily vertical. It's also hard to net them out in your setup, because the position of the magnetron means that thermal forces will be asymmetrical as you invert the frustrum.

If the effect is real, there is no reason to expect it to build over minutes. When you placed the weights on the beam, the response was comparatively immediate. Therefore, a 'kick' on switch-on followed by a slow build due to thermal might be something to look for. I'll go back and peer at that for a while!

My son the engineer commented that he would prefer to be looking for a horizontal force, otherwise thermals will be a confounding factor. Maybe the rotating table of Shawyer's wasn't such a bad idea....

R.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 05:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420264#msg1420264">Quote from: tchernik on 08/27/2015 05:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420252#msg1420252">Quote from: TheTraveller on 08/27/2015 05:09 PM</a>

Agreed.

Shawyer's 1st EMDrive, that he reported on, was highly tunable as attached.

So he clearly KNEW of the variables and designed in methods to deal with them, which says to me this was not his 1st experimental build but his 1st successful experimental build.

Shawyer did have at least a decade or 2 of microwave experience before he built his 1st device, so he had a decent real world microwave background knowledge to work from.

His Experimental unit could tune the top plate, the feed waveguide impedance, and the amount of the bottom dielectric insertion into the frustum for maximum Force generation. Says to me he knew well the devil he was working with. And this was in 2000 - 2002.

I agree. Shawyer's experience surely showed him that he needed to be able to tune the most parameters he could.

And he came with a solution that could tune the geometry (vital for achieving resonance or the "right stuff") and possibly the magnetron's frequency. In this way he just needed to build one test device for covering a big swath of combinations, instead of building one fixed model, seeing it didn't work well or at all, and then build another and another.

During the process Shawyer burnt out 3 magnetrons of 5 he used (probably due to reflected Rf) and partly melted a section of his waveguide assembly. So he learned at the school of "Microwave Hard Knocks 101".

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/27/2015 05:58 PM
Thinking more about driving the balance beam at resonance. It should be possible if the natural frequency of the balance beam is reasonable. What is the natural frequency? When you lift one end a few inches and release it, how much time does it take to complete one cycle returning to near the starting point? And what is the quality factor of the balance beam? How many cycles does it take before the maximum amplitude decays by 3 db?

Knowing the natural frequency, what is the power setting that gives a pulse at the same point in the frustum cycle? Run that power setting to see if it will induce resonance and a detectable sweeping of the laser pointer?

If it is possible to attribute resonance of the measurement system to force from the thruster, then it is just a mater of mathematics and classical mechanics to determine the force. Heating shouldn't be a significant issue, or maybe it will be. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 06:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420269#msg1420269">Quote from: RERT on 08/27/2015 05:56 PM</a>
rfmwguy -

I just spent some time trying to reconcile the results you have with some kind of expectation of how the setup should respond to a thrust.

The apparent slow movement of the balance beam seems simplest to fit to thermal (probably air current related) forces building as the temperature rises. That's also consistent with the apparent direction of the force being upwards in both cases. There could still be thrust, but thermal effects will clutter the results. What's more, I think that's intrinsic to the balance-beam approach, where the measured thrust is necessarily vertical. It's also hard to net them out in your setup, because the position of the magnetron means that thermal forces will be asymmetrical as you invert the frustrum.

If the effect is real, there is no reason to expect it to build over minutes. When you placed the weights on the beam, the response was comparatively immediate. Therefore, a 'kick' on switch-on followed by a slow build due to thermal might be something to look for. I'll go back and peer at that for a while!

My son the engineer commented that he would prefer to be looking for a horizontal force, otherwise thermals will be a confounding factor. Maybe the rotating table of Shawyer's wasn't such a bad idea....

R.

Battery powered, totally self contained, no wires, rotary table is the only way to go.

BUT NOT SO EASY TO BUILD AND GET FULL, REAL TIME, DATA COLLECTION OF ALL OPERATIONAL PARAMETERS.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/27/2015 06:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.

I say, he needs to sharpen up that laser before he does anymore tests. The BIG BLOB of red light with lines crossing in front of it, not along side of it, is not accurate enough to tell what is going on. A sharp pencil at the end of the balance beam would be more accurate.

I also suggest running the full power test first, to heat up the air, before doing the 30% test where it cycles on and off. Hopefully, that will eliminate the buoyancy effects we're seeing.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 06:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420225#msg1420225">Quote from: aero on 08/27/2015 03:01 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420219#msg1420219">Quote from: Rodal on 08/27/2015 02:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.
I agree that the next step should be to flip the truncated cone so that the opposite end is pointing up.

Concerning the power settings: it was a good idea for RFMWGUY to plan to test the power at different settings before we knew what the test results were going to be.  Why? Because the claimed results from Yang and Shawyer are by several orders of magnitude higher than those reported by Tajmar and by NASA. But now that we know that the results are at the very threshold of the measuring ability of this set-up, wouldn't it make sense to only test at 100% (maximum) power setting?

What is the point of testing at lower power setting when even the 100% maximum power setting gives results that are at the threshold of the measurement capability?

I would only test at 100% maximum power setting from now on.  I would conduct the same or more number of power on/ power off time settings. 
This would allow us to look at some statistical distribution, by only testing at 100% maximum power and having several tests power on/ power off/power on/power off.  Testing at only 100% power setting, and conducting a number of such tests would allow to further differentiate between the slow drift that appears unrelated to power, and any other movements.

@rfmwguy - correct me if I am wrong, but I thought the magnetron had only 2 power settings, "off" and 100%. It is the microwave oven control that runs the magnetron at 100% power, but only 30% of the time achieving what is called 30% power level. And it is 30% for cooking, but for the thruster, it is 100% for 30% of the time.

And on a side note, why 30%, why not 50%? Have you been able to calculate the resonate frequency of your foobie stick set-up? It might be interesting if it is possible to drive your balance beam at resonance.
You are correct, ON or OFF. The 30% relates only to the duration of ON during the test period.

I have noted, that the magnetron needs to warm up. I you heard the alarms in the 5 min test, they only began after several ON cycles of a few seconds.

I arbitrarily chose 30% ON time simply to characterize the warm-up time and avaid the risk of damaging the magnetron. I can report that the 1 minute test at 100% ON get the tube up to about 185 deg C at its core. The cheap heatsink it came with had a 160 deg C thermal switch. While the core exceeded 185, I'm sure it would take a lot of time to get the heatsink to 160 C.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/27/2015 06:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420264#msg1420264">Quote from: tchernik on 08/27/2015 05:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420252#msg1420252">Quote from: TheTraveller on 08/27/2015 05:09 PM</a>

Agreed.

Shawyer's 1st EMDrive, that he reported on, was highly tunable as attached.

So he clearly KNEW of the variables and designed in methods to deal with them, which says to me this was not his 1st experimental build but his 1st successful experimental build.

Shawyer did have at least a decade or 2 of microwave experience before he built his 1st device, so he had a decent real world microwave background knowledge to work from.

His Experimental unit could tune the top plate, the feed waveguide impedance, and the amount of the bottom dielectric insertion into the frustum for maximum Force generation. Says to me he knew well the devil he was working with. And this was in 2000 - 2002.

I agree. Shawyer's experience surely showed him that he needed to be able to tune the most parameters he could.

And he came with a solution that could tune the geometry (vital for achieving resonance or the "right stuff") and possibly the magnetron's frequency. In this way he just needed to build one test device for covering a big swath of combinations, instead of building one fixed model, seeing it didn't work well or at all, and then build another and another.
Good point, I thought about that, but the tape had been in place for about 72 hours, less likely to droop over a 6 min test. I'll put a mirror in place of it and securely bolt it on next time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prober on 08/27/2015 07:03 PM
Using Shapeways to 3D Print a Tiny, Fuel Free Microwave EMDrive Thruster?

http://forum.nasaspaceflight.com/index.php?topic=33141.msg1420297#msg1420297
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Abyss on 08/27/2015 07:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420298#msg1420298">Quote from: Prober on 08/27/2015 07:03 PM</a>
Using Shapeways to 3D Print a Tiny, Fuel Free Microwave EMDrive Thruster?

http://forum.nasaspaceflight.com/index.php?topic=33141.msg1420297#msg1420297

The challenge is in getting high power at 24GHz.  Otherwise 3d printing is a great fabrication method for small devices because the tolerances are generally pretty low.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/27/2015 07:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420313#msg1420313">Quote from: Abyss on 08/27/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420298#msg1420298">Quote from: Prober on 08/27/2015 07:03 PM</a>
Using Shapeways to 3D Print a Tiny, Fuel Free Microwave EMDrive Thruster?

http://forum.nasaspaceflight.com/index.php?topic=33141.msg1420297#msg1420297

The challenge is in getting high power at 24GHz.  Otherwise 3d printing is a great fabrication method for small devices because the tolerances are generally pretty low.
Tolerances are handable but good high power amps are expensive   :-\
Turning machine is fine for this dimensions ;) don't need a 3D printer.

EDIT: Nobody knows what produce higher thrust, higher or lower frequencies(If these are no measurement artefacts). I remember there was a discussion about, here some times ago.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 07:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420318#msg1420318">Quote from: X_RaY on 08/27/2015 07:46 PM</a>
... but good high power amps are expensive   :-\

For sure. Which is why I went for a $450 100W 0.5 - 2.5GHz Rf amp with forward & reverse power monitoring and 32 stage (5 bit) adjustable output level control.

The sweetness is in the data and what it will reveal about the operational characteristics of an accelerating EMDrive.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/27/2015 08:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420320#msg1420320">Quote from: TheTraveller on 08/27/2015 07:53 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420318#msg1420318">Quote from: X_RaY on 08/27/2015 07:46 PM</a>
... but good high power amps are expensive   :-\

For sure. Which is why I went for a $450 100W 0.5 - 2.5GHz Rf amp with forward & reverse power monitoring and 32 stage (5 bit) adjustable output level control.

The sweetness is in the data and what it will reveal about the operational characteristics of an accelerating EMDrive.
Yes there are cheap PLL sources for direct synthesis and amps available for 2.4GHz  :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 08/27/2015 08:05 PM
Hi everyone,

I apologize for not keeping you all updated on our progress.

We have been testing for a couple weeks now without any success. As we move on to designing our second prototype we would like to consider changes to our first prototype that might yield results.

We are confident in our methodology to determine resonance; by soldering an SMA panel mount to an identical magnetron’s tap wire we have simulated the signal that will travel through its antenna. We then measure the S11 using a VNA and have found several resonances that agree well with EM Pro simulations.

Our thrust measurement apparatus consists of a laser reflecting off of a mirror mounted on a pendulum onto a position-sensing detector. This device outputs an x and y voltage which is amplified and read by a digital oscilloscope. Our x-axis (perpendicular the cylinders axis) noise is ~20 mV peak to peak while our y-axis noise is ~40 mV peak to peak. [Note 1 V = 1 mm]
 
We still have not been able to run without arcing. However, only a preliminary arc is heard when the magnetron reaches full power within the first second. Another issue we have had is melting Nylon screws. Our HDPE disc is fixed to the movable plate with Nylon screws, which had previously protruded from the HDPE surface. Recently we chose to counter-bore these screws and cover them with small HDPE pucks. Unfortunately this change completely destroyed all resonances we had, although it did seem to protect the screws.

Another major issue in our design is the movable plate. This plate is not in contact with the inside of the cylinder, and efforts to create a closer tolerance fit resulted in arcing. The only method we have devised to maintain mobility and create conductivity is to attach a wire from the back of the movable plate to the outside of the cylinder (blue wires). When only one wire was used we found a displacement in the x direction (~0.75 mm) which oddly only appeared when we were on resonance. However after attaching another wire symmetrically the displacement also disappeared. Our conclusion is that significant currents must travel through this conducting wire only while we are on resonance.

There are probably many decisions that seem odd in our design, there are definitely many things we will do differently next time. I am happy to address any questions, concerns or suggestion.

edit: The mode we think we are exciting is the TM012. We have the ability to get TM111 by increasing HDPE thickness by .6 inches, but haven't figured out how to get a TE mode yet.

Kurt
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: D_Dom on 08/27/2015 08:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420298#msg1420298">Quote from: Prober on 08/27/2015 07:03 PM</a>
Using Shapeways to 3D Print a Tiny, Fuel Free Microwave EMDrive Thruster?

http://forum.nasaspaceflight.com/index.php?topic=33141.msg1420297#msg1420297

I like the size, working with bench top test equipment may provide enough knowledge regarding frequency and power levels to justify miniaturized RF components for "flightweight" experiment.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 08/27/2015 08:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420320#msg1420320">Quote from: TheTraveller on 08/27/2015 07:53 PM</a>

For sure. Which is why I went for a $450 100W 0.5 - 2.5GHz Rf amp with forward & reverse power monitoring and 32 stage (5 bit) adjustable output level control.

The sweetness is in the data and what it will reveal about the operational characteristics of an accelerating EMDrive.

Is this one of the amplifiers you bought in bulk? If so, are you willing to sell one of them?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 08/27/2015 08:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420228#msg1420228">Quote from: Croppa on 08/27/2015 03:07 PM</a>
As other have noted, a great improvement to the current setup would be the ability to trigger it from a distance, although I imagine that's not trivial.

It's not difficult at all, assuming it's not an inverter microwave.

0. Unplug it.
1. Open the microwave oven chassis.
2. Follow the power cord into the chassis, through the fuse, and disconnect it from the next component, probably the control board.
3. Follow the leads back from the transformer to the next component.  Unplug the one that has the control board in the path.
4. Connect the output lead from the fuse to the primary side input of the transformer.

When you plug it in, now the magnetron should turn on.

If you want wireless control you can plug it into one of these $15 IR remote control plugs from Amazon.  http://amzn.to/1VeNmJ0 (http://amzn.to/1VeNmJ0)  My Ace Hardware has one locally for twice the price. :/

Inside the microwave chassis should be a paper wiring diagram.  If you photograph it and send it over I can be more specific on how to bypass the control board and safety interlocks.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 09:18 PM
Not a bad video:

Our adventure is just beginning. Neil deGrasse Tyson examines the upcoming Ares 3 mission and their Journey To Mars in this special episode of StarTalk.

https://www.youtube.com/watch?v=-fdKyszL1Zo

Really gotta make sure some way I watch this movie. Major goosebumps.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 08/27/2015 09:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420331#msg1420331">Quote from: zellerium on 08/27/2015 08:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420320#msg1420320">Quote from: TheTraveller on 08/27/2015 07:53 PM</a>

For sure. Which is why I went for a $450 100W 0.5 - 2.5GHz Rf amp with forward & reverse power monitoring and 32 stage (5 bit) adjustable output level control.

The sweetness is in the data and what it will reveal about the operational characteristics of an accelerating EMDrive.

Is this one of the amplifiers you bought in bulk? If so, are you willing to sell one of them?

So far I'm getting a single sample. They still have not shipped it. Probably make them in batches when the orders get big enough.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 08/27/2015 09:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420234#msg1420234">Quote from: Rodal on 08/27/2015 03:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420228#msg1420228">Quote from: Croppa on 08/27/2015 03:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420220#msg1420220">Quote from: Rodal on 08/27/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...1) There is some unexpected movement that is worth pursuing at a higher measurement resolution; well below 200 mg....
I agree.  Since the movement is at the threshold or below the threshold of what can be measured at the moment, I would only test at 100% power from now on.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...2) FT1 and FT2 produces what I believe to be thermal lift as the magnetron goes through its 6 minute total  testing cycle, equivalent to approximately 500 mg....

I completely agree.  The slow drift looks like a slow thermal artifact and not related to the electromagnetic power on/power off.  We need to distinguish between the slow drift that appears unrelated to the electromagnetic power and other movements that may not be so explained away.

////////////////////////////////////

I hope that you will continue with your experiments  :)

Congratulations again for a very impressive experiment !

It seems to me that the advantage of running at lower power is that it cycles on/off without rfmwguy being close to the setup. As I understand it the on cycles are full power anyway and only the overall proportion of on time is reduced. There are definite oscillations associated with the start of these runs (you can see these more easily in the unstretched montage shown here, as well as the raw video). I suspect these are air currents associated with rfmwguy moving past the apparatus after triggering the run but can't say for sure.

As other have noted, a great improvement to the current setup would be the ability to trigger it from a distance, although I imagine that's not trivial.

Cycling on/off at less than 100% full power constantly on all the cycle time has this undeniable drawback:

 the response at the moment is so small that it is at the threshold or below the threshold of what can be measured.  Therefore one should only test with 100% power constantly on all the cycle time in order to try to maximize the response.  Anything less than 100% power on during the ON cycle will just result in amplifying the relative level of "noise" (thermal and other artifacts) and minimizing the relative level of any possible signal that is not an artifact.

The point seems to be getting missed is that the microwave operates at 100% power at all times. The "power setting" is merely a cycle time within the overall time of the run. A 30% power setting on a 5 minute run means that the machine cycles on and off so that it is operating only 30% of the time. 70% setting means it operates over 70% of the timer interval.

The strength of the microwave, 650 watt, 1000 watt, 1200 watt refers to the power output  while running.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sherman on 08/27/2015 09:52 PM
This is probably a long-shot, but does your microwave have any sort of delay start functionality rfmwguy?

If it did, that could be a simple alternative to remote control.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/27/2015 10:00 PM
Jesus, I'm about to do photo analysis on the internet.  The track record of this kind of analysis is so poor that I suggest you remain highly skeptical about what I'm about to say.

Ok, first I realized that, using the time montage, I might be able to approximate the starting location in the pointer for each run by looking at some of the banding on the display and lining up similar looking bands before the test began.  The audio signals on the first montage meant that starting and ending points were very clear.  Looking at the video and the lines for the second montage I was able to estimate the start if the first run. 

I again looked for similar looking bands at the end state.  I used gimps rectangle tool to highlight this area.  I then compared the location of the two highlighted bands and found a similar end state to within some margin of error.  (I also then inverted the colors on the second run and set it as 50% opaque so that others could check me alignments).

From this I see a couple potential conclusions.
1.  My margin of error has swamped my data analysis.

2.  Despite the changes rmfguy made, the end state was relatively stable.  The magnetron is a very stable part of the device that has been operated in the same manner in both tests.  That would suggest that thermal noise from the magnetron is swamping the test.

3.  End states are stable because approximately the same energy has been loaded into the balance beam each time.  Some defect in the rig is causing it to have an unexpected amount of stickiness.  If I knew more physics I would readily grasp why the beam is returning to its stickied state when perturbed by rmfguys presence.  Perhaps taping the beam at the end of the run and seeing where it stabilizes would give some useful information. 

4.  Lets say I'm right about the maximum possible thrust being described by a mathematical limit.  If this were true we would get thrust x when we load energy y into the system.  By loading energy into the system we do not create thrust but access an undefined thing that creates thrust and shows inertia (continues to move in the thrust direction once you get started, even when power is cut).  Put more energy into the system faster and you move toward the limit faster.  Both runs put a similar amount of energy in, though at different times, and got a similar result out.  That might also suggest that resonance modes just allow you to load energy into whatever it is faster/more efficiently.  I suspect that the limit might be the result of some combination of frequency, volume of the frustum and local speed of light (explaining why thrust falls off in a vacuum).  (Alternatively, some effect involving air that I would readily grasp if I knew what the hell I was doing).

Anyway here is my attempt at reconciling the data, hopefully it'll be more useful than me babbling. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/27/2015 10:30 PM
We still don't know what the vertical scale really means. For example, when a constant force (a weight) is added, does the beam deflect to a fixed position and stay there? Does it return to its previous position without hysteresis when the weight is removed? Is the scale linear over different forces? How does it behave with impulsive forces? etc etc
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/27/2015 10:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420350#msg1420350">Quote from: Bob Woods on 08/27/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420234#msg1420234">Quote from: Rodal on 08/27/2015 03:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420228#msg1420228">Quote from: Croppa on 08/27/2015 03:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420220#msg1420220">Quote from: Rodal on 08/27/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...1) There is some unexpected movement that is worth pursuing at a higher measurement resolution; well below 200 mg....
I agree.  Since the movement is at the threshold or below the threshold of what can be measured at the moment, I would only test at 100% power from now on.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420217#msg1420217">Quote from: rfmwguy on 08/27/2015 02:15 PM</a>
...2) FT1 and FT2 produces what I believe to be thermal lift as the magnetron goes through its 6 minute total  testing cycle, equivalent to approximately 500 mg....

I completely agree.  The slow drift looks like a slow thermal artifact and not related to the electromagnetic power on/power off.  We need to distinguish between the slow drift that appears unrelated to the electromagnetic power and other movements that may not be so explained away.

////////////////////////////////////

I hope that you will continue with your experiments  :)

Congratulations again for a very impressive experiment !

It seems to me that the advantage of running at lower power is that it cycles on/off without rfmwguy being close to the setup. As I understand it the on cycles are full power anyway and only the overall proportion of on time is reduced. There are definite oscillations associated with the start of these runs (you can see these more easily in the unstretched montage shown here, as well as the raw video). I suspect these are air currents associated with rfmwguy moving past the apparatus after triggering the run but can't say for sure.

As other have noted, a great improvement to the current setup would be the ability to trigger it from a distance, although I imagine that's not trivial.

Cycling on/off at less than 100% full power constantly on all the cycle time has this undeniable drawback:

 the response at the moment is so small that it is at the threshold or below the threshold of what can be measured.  Therefore one should only test with 100% power constantly on all the cycle time in order to try to maximize the response.  Anything less than 100% power on during the ON cycle will just result in amplifying the relative level of "noise" (thermal and other artifacts) and minimizing the relative level of any possible signal that is not an artifact.

The point seems to be getting missed is that the microwave operates at 100% power at all times. The "power setting" is merely a cycle time within the overall time of the run. A 30% power setting on a 5 minute run means that the machine cycles on and off so that it is operating only 30% of the time. 70% setting means it operates over 70% of the timer interval.

The strength of the microwave, 650 watt, 1000 watt, 1200 watt refers to the power output  while running.

This point was not being missed at all.  We have microwaves in our kitchens and realize that a 30% power setting means that the magnetron is on only 30% of the time. 

The point is that:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420234#msg1420234">Quote from: Rodal on 08/27/2015 03:47 PM</a>
Cycling on/off at less than 100% full power constantly on all the cycle time has this undeniable drawback:

 the response at the moment is so small that it is at the threshold or below the threshold of what can be measured. 


Since this point is not getting across, let's use stronger language, and make this point more obviously clear.

When the RF power is off, all you have is the trivial situation of a resonant cavity with standing waves.  It is well known that with standing waves, with the RF feed off, the stress is self-cancelling (see http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html ).  The only interesting situation is with the RF feed being on, in which case the magnetron replaces the boundary condition at the big base  and instead of simple standing waves one has travelling waves and mode switching, as shown by the Meep analysis.

The Meep analysis was not conducted with the RF switching from ON to OFF, and being OFF 70% of the time.

We know from the Meep analysis that something interesting and not trivial happens when the RF feed is ON. 

NASA conducted their experiments with the RF feed being ON ALL THE TIME (*), not with the RF feed being off 70% of the time during a cycle.

So why run the power cycling on and off, being off 70% of the time ???? Those are not the conditions run by NASA

Having the RF feed switching from on to off, and spending more time being off than on involves destruction of resonance and changing of conditions, which are different during the on state (travelling waves with different conditions at the big end) than with the RF feed being off (which is one of trivial standing waves, a situation for which it is well known that experiments show NO thrust).

What experimenters have reported thrust with the magnetron being cycled on and off and being off 70% of the cycle time ????

Is there any experimental data showing that having the RF feed OFF 70% of the time produces thrust?

This point would not be so important if the experimental results would be positive, but with experimental results that are practically null, it is of crucial importance, to either have the magnetron ON constantly during the cycle or, to emulate a reported experiment with a reported magnetron's actual cycle time.

___________

(*) Additionally NASA did not use a magnetron, they used an antenna as the RF feed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/27/2015 11:09 PM
Reposted from earlier.

Is this approx 500mg of thermal lift or 100mg of thermal lift and 400mg of something else?  From what I've seen from the published reports everyone who tries to build one of these things goes "got it, thermal effect" then flipped the thing and had a "WTH" moment.  It might be a thermal effect, it probably is a thermal effect, prove that it is a thermal effect.

Despite multiple test reports indicating both a "power on" effect where thrust is delayed for some amount of time and a "power off" effect where thrust lingers, folks seem to be expecting instant on/off.

You have a downward deflection that seems to linger for over a minute without appreciable change, and the rig oscillates before returning to that "stuck" position when rmfguy moves around it.  No appreciable thermal cooling in over a minute seems odd (especially when the frustum is made out of conductive material), not impossible, but certainly odd.

Nobody has thought to check to see at what rate the "stuck" force decays.  Is the rig still in the same position as the 5 minute test after an hour, after a day?  Seems like a smart person could use this information to help identify what is causing the stickiness.

Is the detected force slowly increasing through the experiment as if it were approaching a mathematical limit?

God only knows if rf feed placement has anything to do with this.  We need a clear working test from which we can then move around the feed to see what works best.  Personally, having the feed on either the big or little base worries me a bit.  It seems to be courting Mr. Murphy saying "yes it has to be this way, but when you do this then situation is reversed and it must be on the other end."

Unfortunately, the data seems too noisy to determine if the second run differed from the first.  I'm just saying that my, very bad, data analysis seems to indicate that you got very nearly exactly the same result despite making some fairly gross changes to the test setup.  I'd expect thermal noise to be a bit more random than that.

You are assuming that the entire phenomena is rf in nature.  If I put a paddle wheel in a stream I'm going to get more energy out of the thing than if I break it down and burn the wood.  Given the stickiness of the effect, I have to wonder if the 30% and 100% power tests are showing that you can set something in motion, kill the power for a bit, then feed in more power and get a result (other than thermal noise).  To me this seems critical.  A constant 10kw power supply is going to be hard to get.  If you can instead build up the energy in, for example, a normal resonance cavity and then feed it into the frustum, that is very interesting indeed.

My suggestions:

a.  Flip it.
b.  Make a 5 minute run.
c.  Leave the camera running for 30 minutes
d. Make a 1 minute run
e.  Leave the camera running for 30 minutes

If you get positive results (movement in the opposite direction from thermal lift), start a kickstarter campaign to go buy a very good scale and dump the balance beam setup (we get that lift is not being caused by an easy to detect interaction with a metallic surface, now we need more accurate data).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prober on 08/27/2015 11:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420318#msg1420318">Quote from: X_RaY on 08/27/2015 07:46 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420313#msg1420313">Quote from: Abyss on 08/27/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420298#msg1420298">Quote from: Prober on 08/27/2015 07:03 PM</a>
Using Shapeways to 3D Print a Tiny, Fuel Free Microwave EMDrive Thruster?

http://forum.nasaspaceflight.com/index.php?topic=33141.msg1420297#msg1420297

The challenge is in getting high power at 24GHz.  Otherwise 3d printing is a great fabrication method for small devices because the tolerances are generally pretty low.
Tolerances are handable but good high power amps are expensive   :-\
Turning machine is fine for this dimensions ;) don't need a 3D printer.

EDIT: Nobody knows what produce higher thrust, higher or lower frequencies(If these are no measurement artefacts). I remember there was a discussion about, here some times ago.

may not need a 3D printer but if you wish to experiment with different materials or dual materials its the only way to test cheap and fast.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 08/27/2015 11:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420370#msg1420370">Quote from: Rodal on 08/27/2015 10:45 PM</a>
So why run the power cycling on and off, being off 70% of the time ????

That made sense when checking to see how hot the magnetron would get before actual testing.

You're right, tests should be conducted at 100%. Cycling the power introduces multiple thrust impulses (real, if any, and thermal). Cooling between cycles confuses the situation.

Still, rfmwguy should be careful not to overheat the magnetron on long test runs. Maybe some engineering runs should be done to see how long the magnetron can be safely operated.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rq3 on 08/28/2015 12:00 AM
Let's not forget that the HV supply from a microwave oven is rectified with a single diode. The magnetron is actually only emitting RF at a 50% duty cycle, 50 or 60 times per second (depending on your country).

On another subject, knife edge bearings have been the bane of horologists for centuries. Commonly available and  truly frictionless substitutes are flexural pivots like:
http://flexpivots.com/

Yes, they have a spring constant, but it is indeed constant. Unlike a knife edge.

If you insist on a cheap "knife edge", two tungsten carbide balls adhered to the pivot arm, and "rolling" on a flat tungsten carbide (or even glass) plate will provide a very repeatable pivot.

----------------O-------------------
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 12:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420380#msg1420380">Quote from: RonM on 08/27/2015 11:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420370#msg1420370">Quote from: Rodal on 08/27/2015 10:45 PM</a>
So why run the power cycling on and off, being off 70% of the time ????

That made sense when checking to see how hot the magnetron would get before actual testing.

You're right, tests should be conducted at 100%. Cycling the power introduces multiple thrust impulses (real, if any, and thermal). Cooling between cycles confuses the situation.

Still, rfmwguy should be careful not to overheat the magnetron on long test runs. Maybe some engineering runs should be done to see how long the magnetron can be safely operated.
Have been trying to find very specific operating specs on magnetrons without much success. IOW, I know manufacturers put cheap conventional oven thermal switches on the heatsink that trip at 160 deg C, but nowhere can I find magnetron tube temp specs. Putting a thermal sensor on a heatsink simply retards the temp rise from the tube itself. If anyone can pull up the core (tube) operating temperature, it would be appreciated.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rq3 on 08/28/2015 01:04 AM
Your experiment is fantastic! And I'm glad to see that someone is finally looking into the details of the "drive source". Something that has never been mentioned is that every oven magnetron has a ferrite sleeve magnet around the tube. The axial field from the magnet causes the electrons from the cathode filament to "whistle" around the slots in the anode. Similar to blowing across the neck of a bottle.

The magnetic field varies with temperature, and the entire assembly, as a vacuum tube with a hot cathode, is designed to operate at quite a high temperature.

The variation of the magnetic field with temperature has never been addressed in any experiment I've seen. If the magnetron is anywhere near a ferromagnetic material, it will exhibit a varying (decreasing) magnetic "pull" as it warms up. The frequency and power output of the device will also shift, appreciably, during this process.

In short, you have a variable frequency microwave source. It's frequency is very noisy in any domain you care to examine. It is very temperature sensitive. It increases in temperature during operation. It also has a magnetic field, required for its operation, which strength varies with temperature.

I've said it before. I'll say it again. Design any frustum you like. Any shape (Cannae or Shawyer). THEN tune your SOURCE to what you've built for maximum Q in the cavity you have at hand. Trying to design a high Q cavity (a narrow bandpass filter), for a magnetron is like trying to filter the air in the water from a fire hose using a window screen.

On another note. The angle of reflection equals the angle of incidence. Reflecting the detection laser from a mirror mounted on the suspension beam doubles your resolution.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/28/2015 01:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420380#msg1420380">Quote from: RonM on 08/27/2015 11:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420370#msg1420370">Quote from: Rodal on 08/27/2015 10:45 PM</a>
So why run the power cycling on and off, being off 70% of the time ????

That made sense when checking to see how hot the magnetron would get before actual testing.

You're right, tests should be conducted at 100%. Cycling the power introduces multiple thrust impulses (real, if any, and thermal). Cooling between cycles confuses the situation.

Still, rfmwguy should be careful not to overheat the magnetron on long test runs. Maybe some engineering runs should be done to see how long the magnetron can be safely operated.

I'd really like to see the deflection from a clean 30% run with the balance left undisturbed for 15-30 minutes afterwards so that it returns to the initial condition, the same for a 100% run and then a 30% + 100% run (like rfmguy has been doing) with balance left to return to initial condition.  I'd like to make sure the stickiness is part of the rig and not the effect.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/28/2015 01:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420399#msg1420399">Quote from: SteveD on 08/28/2015 01:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420380#msg1420380">Quote from: RonM on 08/27/2015 11:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420370#msg1420370">Quote from: Rodal on 08/27/2015 10:45 PM</a>
So why run the power cycling on and off, being off 70% of the time ????

That made sense when checking to see how hot the magnetron would get before actual testing.

You're right, tests should be conducted at 100%. Cycling the power introduces multiple thrust impulses (real, if any, and thermal). Cooling between cycles confuses the situation.

Still, rfmwguy should be careful not to overheat the magnetron on long test runs. Maybe some engineering runs should be done to see how long the magnetron can be safely operated.

I'd really like to see the deflection from a clean 30% run with the balance left undisturbed for 15-30 minutes afterwards so that it returns to the initial condition, the same for a 100% run and then a 30% + 100% run (like rfmguy has been doing) with balance left to return to initial condition.  I'd like to make sure the stickiness is part of the rig and not the effect.

Now that is thinking outside of the box!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/28/2015 01:53 AM
How far would you push running the magnetron off for a cycle time until deciding that it doesn't emulate the conditions of those who reported thrust for EM Drive experiments?

30% on means 70% of the time off (who run EM Drive experiments and reported thrust with the magnetron off for 70% of the time ?, did Shawyer do that? did Yang do that?)  How did Iulian Berca cycle the ON time fo the magnetron in his experiment ?

how about OFF for 99.999% of the cycle time?  Would people agree that is too long of a time off ? So can we agree that there is a point at which the time off is so long that it is disruptive to the traveling waves in the cavity?

Particularly when the experiment is showing practically no measurable response, is the best way to re-run the experiment so that the magnetron  is OFF most of the cycle time ?

Shouldn't the aim be to run the magnetron constantly ON (*) for increasing periods of time such that its temperature does not exceed a given temperature (considered to be the upper safe limit) and then turn it off and wait until it cools down ?

_________
(*) yes, subject to 60 Hz under those conditions


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 02:16 AM
Lots of good discussions on cycle times. Previous experiments seemed to all be short duration only. The keypad gives me lots of time options including 10% steps to 100% power cycle.

Before I record further, I'll begin a long phase of upgrades to get better resolution.

I must say that the suspected thermal lift is far more than I expected using mesh. I cannot imagine any other vertical force. Well, antigravity, but that's about as likely as bigfoot knocking on my door...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/28/2015 02:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420407#msg1420407">Quote from: rfmwguy on 08/28/2015 02:16 AM</a>
....I must say that the suspected thermal lift is far more than I expected using mesh. I cannot imagine any other vertical force. Well, antigravity, but that's about as likely as bigfoot knocking on my door...
The mesh on the lateral conical walls reduced the effect of air density decreasing inside the truncated cone.

However, as you measured, the highest temperature, by far occurs at the magnetron instead of inside the cone.  Therefore the air density is reduced next to the magnetron.  This produces natural convection thermal currents, due to the difference in density of the hot air next to the magnetron, with the ambient air.  This natural convection thermal current produced by the magnetron is the one responsible for the lifting force.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/28/2015 04:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420410#msg1420410">Quote from: Rodal on 08/28/2015 02:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420407#msg1420407">Quote from: rfmwguy on 08/28/2015 02:16 AM</a>
....I must say that the suspected thermal lift is far more than I expected using mesh. I cannot imagine any other vertical force. Well, antigravity, but that's about as likely as bigfoot knocking on my door...
The mesh on the lateral conical walls reduced the effect of air density decreasing inside the truncated cone.

However, as you measured, the highest temperature, by far occurs at the magnetron instead of inside the cone.  Therefore the air density is reduced next to the magnetron.  This produces natural convection thermal currents, due to the difference in density of the hot air next to the magnetron, with the ambient air.  This natural convection thermal current produced by the magnetron is the one responsible for the lifting force.

That is an interesting thought not to be discarded out of hand, but has anyone put numbers on the force detected? Has anyone put numbers on the drag force limits of the "natural convection thermal currents?" Has anyone put numbers on the lift force response (time constant) of a hot air balloon heated by 1 kw?

I expect we are all hoping for a more definitive laser spot trace from future runs. Still, I think some bounds could be established for some of these error sources. It is one thing to say, "I think it is that." It is quite a different thing to say, "The numbers show that it is that within these limits, and here are my calculations," as Warptech does.

And of course I'm as guilty as anyone.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 08/28/2015 04:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420427#msg1420427">Quote from: aero on 08/28/2015 04:00 AM</a>
(...) I expect we are all hoping for a more definitive laser spot trace from future runs. (...)
Yes, perhaps  we could use something like this:
http://www.instructables.com/id/Desktop-Michelson-Morely-Interferometer/
or even this:
https://www.youtube.com/watch?v=n90whRO-ypE&hd=1 (https://www.youtube.com/watch?v=n90whRO-ypE&hd=1)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/28/2015 05:18 AM
I still meet up with my old buddies from National.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/28/2015 09:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420392#msg1420392">Quote from: rfmwguy on 08/28/2015 12:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420380#msg1420380">Quote from: RonM on 08/27/2015 11:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420370#msg1420370">Quote from: Rodal on 08/27/2015 10:45 PM</a>
So why run the power cycling on and off, being off 70% of the time ????

That made sense when checking to see how hot the magnetron would get before actual testing.

You're right, tests should be conducted at 100%. Cycling the power introduces multiple thrust impulses (real, if any, and thermal). Cooling between cycles confuses the situation.

Still, rfmwguy should be careful not to overheat the magnetron on long test runs. Maybe some engineering runs should be done to see how long the magnetron can be safely operated.
Have been trying to find very specific operating specs on magnetrons without much success. IOW, I know manufacturers put cheap conventional oven thermal switches on the heatsink that trip at 160 deg C, but nowhere can I find magnetron tube temp specs. Putting a thermal sensor on a heatsink simply retards the temp rise from the tube itself. If anyone can pull up the core (tube) operating temperature, it would be appreciated.
panasonic  http://www.rell.com/filebase/en/tsrc/Datasheets/2M244-M10G.pdf
matsushita  http://mail.blockyourid.com/~gbpprorg/mil/herf/2M167B-M15.pdf
hokuto   http://www.hokuto.co.jp/eng/products/magnetron/pdf/brochure.pdf

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/28/2015 10:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420278#msg1420278">Quote from: WarpTech on 08/27/2015 06:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420054#msg1420054">Quote from: deltaMass on 08/27/2015 08:27 AM</a>
Early days for drawing any conclusions. Of course, you try the big and obvious things first. Repositioning the magnetron was one such trial. I'd suggest another big and obvious one would be to flip the frustum over so now it's small side up. Does the thrust reverse? That is what Iulian found.

I say, he needs to sharpen up that laser before he does anymore tests. The BIG BLOB of red light with lines crossing in front of it, not along side of it, is not accurate enough to tell what is going on. A sharp pencil at the end of the balance beam would be more accurate.

I also suggest running the full power test first, to heat up the air, before doing the 30% test where it cycles on and off. Hopefully, that will eliminate the buoyancy effects we're seeing.
Todd
Flip the mirror 90 degrees.  It's a camera tripod.  There should be a 90 degree flip adjustment.  Turn the vertical line into a horizontal line that way.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: andygood on 08/28/2015 10:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420410#msg1420410">Quote from: Rodal on 08/28/2015 02:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420407#msg1420407">Quote from: rfmwguy on 08/28/2015 02:16 AM</a>
....I must say that the suspected thermal lift is far more than I expected using mesh. I cannot imagine any other vertical force. Well, antigravity, but that's about as likely as bigfoot knocking on my door...
The mesh on the lateral conical walls reduced the effect of air density decreasing inside the truncated cone.

However, as you measured, the highest temperature, by far occurs at the magnetron instead of inside the cone.  Therefore the air density is reduced next to the magnetron.  This produces natural convection thermal currents, due to the difference in density of the hot air next to the magnetron, with the ambient air.  This natural convection thermal current produced by the magnetron is the one responsible for the lifting force.

How about replacing the magnetron with a heating element, ideally one which can match the temperature curve of the magnetron's heat sink, and re-run the test. Better yet, lose the magnetron but keep the heat sink, to retain it's geometry, and somehow heat it to the same temperature it reached during the previous tests...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Cedalion on 08/28/2015 10:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420183#msg1420183">Quote from: bunjatec on 08/27/2015 11:58 AM</a>
Hi, Another noob here lurking..  :)

Just saw this
http://phys.org/news/2015-08-theory-radiationless-revolution.html (http://phys.org/news/2015-08-theory-radiationless-revolution.html)

With the talk of poloidal fields this new theory seems relevant, hope it's useful..

Came on here to post this as well, though I am certainly not across the physics on this.
Here is the Nature paper:
http://www.nature.com/ncomms/2015/150827/ncomms9069/full/ncomms9069.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/28/2015 11:19 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419886#msg1419886">Quote from: rfmwguy on 08/26/2015 06:48 PM</a>

As a side note, when I came back near the experiment at the end of the test run, I felt no warmer air than when I started, but did notice an unusual "ambiance'" to the air. Best way I can describe it as metallic, ionized air. This is not scientific obviously, just a minor observation I did not notice during static testing.

A hint for a kind of Biefeld-Brown effect?

If air is ionized then it can be accelerated, it is a good explanation why in previous tests the thrust seems to decrease in imperfect vacuum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/28/2015 11:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420549#msg1420549">Quote from: OttO on 08/28/2015 11:19 AM</a>
If air is ionized then it can be accelerated, it is a good explanation why in previous tests the thrust seem to decrease in imperfect vacuum.

Perhaps the electrostatic charge needs some time to build up (several seconds) and then stay on when the magnetron is off...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 08/28/2015 11:25 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420518#msg1420518">Quote from: Cedalion on 08/28/2015 10:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420183#msg1420183">Quote from: bunjatec on 08/27/2015 11:58 AM</a>
Hi, Another noob here lurking..  :)

Just saw this
http://phys.org/news/2015-08-theory-radiationless-revolution.html (http://phys.org/news/2015-08-theory-radiationless-revolution.html)

With the talk of poloidal fields this new theory seems relevant, hope it's useful..

Came on here to post this as well, though I am certainly not across the physics on this.
Here is the Nature paper:
http://www.nature.com/ncomms/2015/150827/ncomms9069/full/ncomms9069.html

Reminds me very much of the Cannae drive configuration...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 11:58 AM
Morning coffee musings - I have to comment that both here and on reddit (maybe elsewhere?) there is a lot of interesting back and forth on NSF-1701 2 flight tests. Most commentary has been pretty useful IMO and that which is not is quickly pointed out by other posters. Perhaps this type of collaborative discussion is going on about other things on the interwebs, but I've not seen it.

Look at the length of these 4 threads and the new daily threads on reddit. Pretty indicative that the project has tons of grass-roots, scientific interest out there. All done without national advertising or institutional promotion.

Look forward to more from other experiments and hope they keep the open disclosure movement going. Any real data, successful or otherwise is more than we have right now.

p.s. My advice to other builders? Check your ego at the door. Open disclosure with experiments is not for those with insecurity issues. Just providing data is rewarding enough and people out there appreciate it. So get those cameras rolling and jump into the hot tub...the water's fine  ;)

"Frustum" courtesy of: http://www.sears.com/swimline-pooltunes-floating-speaker-light/p-SPM7786027802?hlSellerId=13467&sid=IDx20110310x00001i&kpid=SPM7786027802&kispla=SPM7786027802&mktRedirect=y
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/28/2015 02:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420427#msg1420427">Quote from: aero on 08/28/2015 04:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420410#msg1420410">Quote from: Rodal on 08/28/2015 02:29 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420407#msg1420407">Quote from: rfmwguy on 08/28/2015 02:16 AM</a>
....I must say that the suspected thermal lift is far more than I expected using mesh. I cannot imagine any other vertical force. Well, antigravity, but that's about as likely as bigfoot knocking on my door...
The mesh on the lateral conical walls reduced the effect of air density decreasing inside the truncated cone.

However, as you measured, the highest temperature, by far occurs at the magnetron instead of inside the cone.  Therefore the air density is reduced next to the magnetron.  This produces natural convection thermal currents, due to the difference in density of the hot air next to the magnetron, with the ambient air.  This natural convection thermal current produced by the magnetron is the one responsible for the lifting force.

That is an interesting thought not to be discarded out of hand, but has anyone put numbers on the force detected? Has anyone put numbers on the drag force limits of the "natural convection thermal currents?" Has anyone put numbers on the lift force response (time constant) of a hot air balloon heated by 1 kw?

I expect we are all hoping for a more definitive laser spot trace from future runs. Still, I think some bounds could be established for some of these error sources. It is one thing to say, "I think it is that." It is quite a different thing to say, "The numbers show that it is that within these limits, and here are my calculations," as Warptech does.

And of course I'm as guilty as anyone.
Yes, we could put numbers on the thermal convection forces (*) and compare with the electromagnetic force to arrive at the conclusion that the long-term drift that doesn't recover by the end of the test cannot be an electromagnetic effect. 

One doesn't have to obtain an exact closed form solution to arrive at this conclusion, a simple back of the envelope estimate can show this.  This has already been done a number of times in previous threads: it was well covered by frobnicat in thread 1 and 2, as well as DeltaMass and others for Iulian Berca's test in later threads.  Zen-In had a number of posts as well.  Even Greg Egan and others posted such an estimate on Prof. John Baez's webpage about "the incredible shrinking force of the EM Drive".

When I first came into these threads (thread 1) I had a long post analyzing thermal effects.

This is something that NASA researchers have also recognized: they don't deny the thermal effects, on the contrary, far from denying them, they have done their best to analyze them and redo their tests to separate the thermal effects.

I think that the fact that the long-term drift in these latest tests cannot be an electromagnetic effect is so clear that it is not necessary to repeat all those calculations.  This is kind of self-evident after those previous discussions.  Anyway, it seems that people thinking that the long-term not-recovered-by-the-end-of-the-test effect can be an electromagnetic effect are not going to be convinced by resuscitating those thermal calculations. So, I am not going to repeat them, repeating them seems like a futile exercise.

Rather than argue again about whether these long-term drift that doesn't promptly recover are or are not thermal effects, it seems that the most expedient thing (at least for me :)  ) is to wait for RFMWGUY to run experiments with the EM Drive turned upside down, and compare the experimental results.

_______
(*) For example, by using non-dimensional parameters to estimate the rise times and decay times of the forces involved

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/28/2015 02:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420613#msg1420613">Quote from: rfmwguy on 08/28/2015 11:58 AM</a>
Morning coffee musings - I have to comment that both here and on reddit (maybe elsewhere?) there is a lot of interesting back and forth on NSF-1701 2 flight tests. Most commentary has been pretty useful IMO and that which is not is quickly pointed out by other posters. Perhaps this type of collaborative discussion is going on about other things on the interwebs, but I've not seen it.

Look at the length of these 4 threads and the new daily threads on reddit. Pretty indicative that the project has tons of grass-roots, scientific interest out there. All done without national advertising or institutional promotion.

Look forward to more from other experiments and hope they keep the open disclosure movement going. Any real data, successful or otherwise is more than we have right now.

p.s. My advice to other builders? Check your ego at the door. Open disclosure with experiments is not for those with insecurity issues. Just providing data is rewarding enough and people out there appreciate it. So get those cameras rolling and jump into the hot tub...the water's fine  ;)

"Frustum" courtesy of: http://www.sears.com/swimline-pooltunes-floating-speaker-light/p-SPM7786027802?hlSellerId=13467&sid=IDx20110310x00001i&kpid=SPM7786027802&kispla=SPM7786027802&mktRedirect=y
I have no problem with sharing or being open. But right now I'm faced with putting this thing together right. Spending time on the blogs is a great research mindmeld for the basics but now it's come down to a one on one.

Here are just a few things I'm addressing or doing or on the list to do.

I've had to trash the idea of the cement in the tub to stabilize the anti-vibration platforms when when I picked up the 75 pound support columns and sat it in the tub the cement cracked. Poo. So I'm not using them. Layout and build new support stands.

The power supply I was using for the magnetron toasted, did a techie ppphhhhtttt... fried a HV diode from a bad cap or vice versa. Rebuilding and modifying another.

The PETG I used for the sheeting on the walls looked as if it was going to work well at isolating air proved to be way too much a static generator, when my SO decided to do some grinding of bondo on a car in the back of the shop it sucked up it all so bad I couldn't even see through it... All of it was just taken down yesterday.

The knife edges had to be redone to a smoother rolling surface.

I'm having real issues in getting my current design to work in TE012 through meep simulation and may end up like you directing the magnetron directly into the frustum but that has issues with extra heat on the magnetron with it's current sink and that heat that needs to be addressed. Was up till 1am last night working on it. The waveguides prove proved way to costly new at this time and it seems WR 340 and 430 hardware is scarce on ebay and other sites.

The laptop I bought from Ebay for she shop has charging issues and will not charge. Ordered 2 different chargers and neither one work so it's the laptop. Want to get a replacement and have contacted the seller but nothing back yet.

Looking into a iphone 5 with a Flir one attachment unlocked to get thermal images of the frustum but still need to figure a way to migrate the data to the PC. My camera is someplace in Nebraska visiting a grandmother. I've asked another Ham friend to drop over this weekend with his camera (I repaired his very nasty virus infected laptop, some 8 year old decided to visit porn sites. lmao)

Working on getting the Rassberry pi up and going with the motion XYZ acceleration modules. Need more time spent on the blog sites to figure out.

Still waiting for some stuff from a slow boat from China, connectors and little dodadds.

It boils down to this, focus on building the best DYI I can. It's that simple and I don't want to let anyone down so I'm sorry to not be as verbal as I have been. Time is the fire in which we all burn. Love that corny saying.

Shell

Added. I haven't see my hot tub is a week... maybe this morning, after shopping and dishes.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/28/2015 02:58 PM
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. Cal Poly students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 08/28/2015 03:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420648#msg1420648">Quote from: Rodal on 08/28/2015 02:22 PM</a>
I think that the fact that the long-term drift in these latest tests cannot be an electromagnetic effect is so clear that it is not necessary to repeat all those calculations.  This is kind of self-evident after those previous discussions.  Anyway, it seems that people thinking that the long-term not-recovered-by-the-end-of-the-test effect can be an electromagnetic effect are not going to be convinced by resuscitating those thermal calculations. So, I am not going to repeat them, repeating them seems like a futile exercise.

I shall confess that the ozone smell rfmguy talked about is worrying me, if in the magnetron we have a kind of corona effect the apparatus could take an electrostatic charge even after the magnetron is shut down

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/28/2015 03:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results, for example:  Mulletron's experiment who deserves to be recognized as the true leader in these Do-It-Yourself experiments, had null results documented in early threads, also the experiments with the experimenter that had constant cross-section waveguide and was using dielectric inserts, gave null results.

I understand that null results in these experiments don't close the book, as any experiment is limited on what can be tested (type of force measurement, set-up, etc.), but as Shell, says, "there is no bad data" and we should not forget those null results as well, as they are part of the big picture.

The big picture that is emerging is that if there is any EM Drive force (yes, it may be zero), its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

The force/InputPower reported by Iulian Berca was similar to the one reported by NASA.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/28/2015 03:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results, for example:  Mulletron's experiment who was the leader in such experiments, had null results documented in early threads, also the experiments with the experimenter that had constant cross-section waveguide and was using dielectric inserts, gave null results.

I understand that null results in these experiments don't close the book, as any experiment is limited on what can be tested (type of force measurement, set-up, etc.), but as SeeShell, says, "there is no bad data" and we should not forget those null results as well, as they are part of the big picture.

The big picture that is emerging is that if there is any EM Drive force, it is either zero or its force/InputPower magnitude is of the magnitude reported by NASA and by Dresden University (Tajmar) but not at all the magnitudes reported by Shawyer and Yang - who nobody has been able to reproduce-

The force/InputPower reported by Iulian Berca was similar to the one reported by NASA.
I agree with the big picture you quoted and I'm almost obsessed with squeezing the best I can from a DYI point and putting a thumbtack on it.

I NEED to get some shopping done lol... be back later... well ... after a hot tub. Then I have so much to get done.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: hhexo on 08/28/2015 03:35 PM

Sorry, a couple of stupid questions here...

Is the loud beeping the microwave leak detector going off? It beeps a lot during the full power run, and it's quite loud. It's true that sound waves are not really that powerful (milliwatts? microwatts?), but they might be hitting the frustum and pushing it by being reflected asymmetrically... the pitch is quite high, and even an A5 pitch has a wavelength small enough to be reflected by an apparatus of that size. If you want to keep the detector, having a light-based indicator rather than sound-based could reduce another possible source of... noise! (yes you probably saw that pun coming :) )

Also, as others have suggested, an ozone detector could be a good way of checking whether there was any ionization.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420666#msg1420666">Quote from: OttO on 08/28/2015 03:07 PM</a>
I shall confess that the ozone smell rfmguy talked about is worrying me, if in the magnetron we have a kind of corona effect the apparatus could take an electrostatic charge even after the magnetron is shut down

And in addition to the electric effect... If I'm not mistaken ozone is still an ideal gas at room temperature, so pV=nRT for it as well. However, turning a chunk of oxygen into ozone reduces the number of its molecules to 2/3 of the original number (O2 becoming O3). Density will stay pretty much the same (same number of atoms, almost the same mass), but pressure will locally be lower, and in order to equalize it (through the mesh) there could be further gas currents of non-thermal origin.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 08/28/2015 04:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420685#msg1420685">Quote from: deltaMass on 08/28/2015 03:50 PM</a>
Has anyone contacted Yang with a view to touring her lab?
Yes, Chinese military connections, I know. It's a Hail Mary type question.

Which raises the question - if you're behind the Great Firewall of China, can you access NSF?
Or even (given the fact that Chinese are banned by NASA from visiting ISS) does NASA block China access to NSF?

NASA has no regulation attributions over Internet sites that aren't theirs AFAIK, and this forum was just created to discuss NASA's activities and spaceflight in general, but it is privately owned and thus, a fully independent entity from NASA.

About this site being accessible in China, no idea, but I can't think of any reason for it not to be. The topics are narrow and focused on space activities, well moderated and far away from anything controversial for the PRC.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Abyss on 08/28/2015 04:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results

The big picture that is emerging is that if there is any EM Drive force, it is either zero or its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

Yeah this is an important point.  We need to determine what Yang/Shawyer did that the current DIY's are missing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 04:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420695#msg1420695">Quote from: Abyss on 08/28/2015 04:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results

The big picture that is emerging is that if there is any EM Drive force, it is either zero or its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

Yeah this is an important point.  We need to determine what Yang/Shawyer did that the current DIY's are missing.
I'll hate myself for saying this later, but: Unreasonable Q factors is my guess.

If Q is part of their thrust equations, higher Q will yield higher predictive thrust.

(I am so ashamed of myself)  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/28/2015 04:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420693#msg1420693">Quote from: tchernik on 08/28/2015 04:04 PM</a>


About this site being accessible in China, no idea, but I can't think for any reason for it not to be. The topics are narrow and focused on space activities, well moderated and far away from anything controversial for the PRC.

open source intelligence gathering is a huge part of all national intelligence programs. Thus they all have people reading every newspaper, trade journal, newspapers, magazines, video media, science journals, published patent documents and even websites. Also they have students who are not just there for degrees learning everything they can and working at cutting edge corporations. Open source stuff as insignificant as an organizational chart, project patch or decal or telephone roster are of interest to intelligence collectors.

this is nearly as big a deal as more covert spying tactics.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/28/2015 05:14 PM
My guess is that Yang reads this but cannot post.

I think I'm correct in saying that a Yang replication is not possible because she did not give sufficient data for independent construction to occur.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/28/2015 05:17 PM

We are considering doing two experiments with an industrial magnetron transmitter  (c/w waveguide launcher, isolator and waterload) and the University of Saskatoon; either a 100kW continuous into a copper frustrum 932Hz at TE012 (designing cooling system now..) or 5MW 10microsecond pulses. Looks like we would also try having the magnetron fire into the small base or the big base, maybe some with ports on the side. Have some ANSYS modelling going down now. We would also fire the unit towards the ground that buoyant effects are not in play (I don't know why anyone would aim to produce thrust in the up position right now since hot air rising / buoyant is probably the #1 explanation for positive tests). Objective would be to produce a non-null result an order of magnitude above background.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. Cal Poly students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/28/2015 05:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420716#msg1420716">Quote from: CraigPichach on 08/28/2015 05:17 PM</a>
We are considering doing two experiments with an industrial magnetron transmitter  (c/w waveguide launcher, isolator and waterload) and the University of Saskatoon; either a 100kW continuous into a copper frustrum 932Hz at TE012 (designing cooling system now..) or 5MW 10microsecond pulses. Looks like we would also try having the magnetron fire into the small base or the big base, maybe some with ports on the side. Have some ANSYS modelling going down now. We would also fire the unit towards the ground that buoyant effects are not in play (I don't know why anyone would aim to produce thrust in the up position right now since hot air rising / buoyant is probably the #1 explanation for positive tests). Objective would be to produce a non-null result an order of magnitude above background.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. Cal Poly students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.
That's very ambitious. I assume you mean 932 MHz. With high power and a bespoke cooling system, I assume you cannot make this standalone?

Producing thrust signatures in any direction is fruitful. The idea is to flip 180o and retest, thus subtracting out common mode effects.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/28/2015 05:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420704#msg1420704">Quote from: rfmwguy on 08/28/2015 04:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420695#msg1420695">Quote from: Abyss on 08/28/2015 04:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results

The big picture that is emerging is that if there is any EM Drive force, it is either zero or its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

Yeah this is an important point.  We need to determine what Yang/Shawyer did that the current DIY's are missing.
I'll hate myself for saying this later, but: Unreasonable Q factors is my guess.

If Q is part of their thrust equations, higher Q will yield higher predictive thrust.

(I am so ashamed of myself)  8)
I know I'm only an armchair experimenter at this point, but if I may make a suggestion, it's that you first flip the frustum, and after that work on a good impedance match.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Abyss on 08/28/2015 05:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420716#msg1420716">Quote from: CraigPichach on 08/28/2015 05:17 PM</a>
We are considering doing two experiments with an industrial magnetron transmitter  (c/w waveguide launcher, isolator and waterload) and the University of Saskatoon; either a 100kW continuous into a copper frustrum 932Hz at TE012 (designing cooling system now..) or 5MW 10microsecond pulses. Looks like we would also try having the magnetron fire into the small base or the big base, maybe some with ports on the side. Have some ANSYS modelling going down now. We would also fire the unit towards the ground that buoyant effects are not in play (I don't know why anyone would aim to produce thrust in the up position right now since hot air rising / buoyant is probably the #1 explanation for positive tests). Objective would be to produce a non-null result an order of magnitude above background.

Well one problem is that the orientation for downward thrust depends on the theory you are following.  So as stated previously you'll want to repeat the experiment in both configurations anyways.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/28/2015 05:54 PM
Interesting news:
http://arxiv.org/pdf/1506.08614v1.pdf
LHC confirms measurements of branching fraction ratio of tau-leptons at BaBar and Belle.

" This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the Standard Model."

Leptons are charged particles almost equal to electrons but much heavier, and it could(seems to) be there are a coupling of charged particles to a unknown scalar field.
2.1 sigma means there is over 95% evidence rate!
Maybe there is really a "new, unknown kind of physics"  in addition to the standard model ::)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/28/2015 06:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results, for example:  Mulletron's experiment who deserves to be recognized as the true leader in these Do-It-Yourself experiments, had null results documented in early threads, also the experiments with the experimenter that had constant cross-section waveguide and was using dielectric inserts, gave null results.

I understand that null results in these experiments don't close the book, as any experiment is limited on what can be tested (type of force measurement, set-up, etc.), but as Shell, says, "there is no bad data" and we should not forget those null results as well, as they are part of the big picture.

The big picture that is emerging is that if there is any EM Drive force (yes, it may be zero), its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

The force/InputPower reported by Iulian Berca was similar to the one reported by NASA.

I guess I'm looking at a bigger picture.  Regardless of force/power, the BIG question is whether the force is real, in which case there is something going on that accepted physics cannot explain.

The efficiency can be worked out later.  We have no idea what the parameters affecting efficiency even ARE.  The whole effect could have massive non-linearities in it allowing orders of magnitude changes with small changes in these unknown parameters.  EVERYONE could be right.

Big picture: eliminate artifacts, then repeatability, repeatability, repeatability.  Then theory?   Then parameter variation to increase efficiency (faster WITH theory, but possible without).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420727#msg1420727">Quote from: deltaMass on 08/28/2015 05:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420704#msg1420704">Quote from: rfmwguy on 08/28/2015 04:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420695#msg1420695">Quote from: Abyss on 08/28/2015 04:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420665#msg1420665">Quote from: deltaMass on 08/28/2015 02:58 PM</a>
SeeShells and The Traveller are close to running their DIY experiments. Aachen seem to have gone quiet for a while. SLOtown students are chugging along too. Together with EW and rfmwguy, that makes six currently-active experiments. Did I miss any?

Is the wiki current?
http://emdrive.wiki/Building
There's a lot more than 6 there.

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results

The big picture that is emerging is that if there is any EM Drive force, it is either zero or its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

Yeah this is an important point.  We need to determine what Yang/Shawyer did that the current DIY's are missing.
I'll hate myself for saying this later, but: Unreasonable Q factors is my guess.

If Q is part of their thrust equations, higher Q will yield higher predictive thrust.

(I am so ashamed of myself)  8)
I know I'm only an armchair experimenter at this point, but if I may make a suggestion, it's that you first flip the frustum, and after that work on a good impedance match.
Think I'll wait for a flip until I solve some measurement resolution issues first. Doing research today and think I'm onto something big. Will post details later.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/28/2015 06:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420716#msg1420716">Quote from: CraigPichach on 08/28/2015 05:17 PM</a>
We are considering doing two experiments with an industrial magnetron transmitter  (c/w waveguide launcher, isolator and waterload) and the University of Saskatoon; either a 100kW continuous into a copper frustrum 932Hz at TE012 (designing cooling system now..) or 5MW 10microsecond pulses. Looks like we would also try having the magnetron fire into the small base or the big base, maybe some with ports on the side. Have some ANSYS modelling going down now. We would also fire the unit towards the ground that buoyant effects are not in play (I don't know why anyone would aim to produce thrust in the up position right now since hot air rising / buoyant is probably the #1 explanation for positive tests). Objective would be to produce a non-null result an order of magnitude above background.



That should produce a more noticeable result.   More power -> more heat and more ionization + 3rd order effects that haven't even been considered yet.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 08/28/2015 07:18 PM
I finally finished the loop antenna modeling exercise.  Not sure if this is still useful but I will post here.   Likely the patterns are the most useful part - as they should give some idea of what modes can be stimulated.   

These models and results are made using a version of the NEC codes (specifically EZNEC).  NEC antenna modeling is not perfect but if you stay within the constraints it can produce qualitatively useful results.   As with all such models, quantitative results are highly dependent on many factors including geometry, signal quality, and many more.   Hopefully these will be of use - particularly if the loops are in a spherical chicken in a vacuum.

I modeled three sizes of antenna 1/2, 1, and 2 wavelength circumference, at three different heights - 1/4, 1/2 and 1 wavelength.   Also modeled each of these configurations for loops both parallel to and normal to their ground plane.

Sorry for how long this took - as some of you know I have been in the process of retiring and unfortunately this exercise mostly had to take place late in evening after all other boring but necessary stuff had been done.  I am now free and hope to start detailed planning for my own DIY experiments soon.

Herman
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 07:56 PM
OK, ready to change test setup a bit after much thought and planning.

Three words: Laser Displacement Sensor

Basically mount the sensor under the opposite end to NSF-1701 and measure displacement of end of balance beam. This is a non-contact, triangulation-based micrometer measuring system typically used to measure surface mount component height in pick and place assemblies.

The data rates are overkill for what we're trying to measure, but it could be translated into a nice chart or data set.

Now, here's the bad news...too expensive for a unique-use home budget. Best I ask for a loaner or donation, but am convinced this is the way to go; avoiding long throw lasers, mirrors and targets.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/28/2015 08:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420761#msg1420761">Quote from: graybeardsyseng on 08/28/2015 07:18 PM</a>
I finally finished the loop antenna modeling exercise.  Not sure if this is still useful but I will post here.   Likely the patterns are the most useful part - as they should give some idea of what modes can be stimulated.   

These models and results are made using a version of the NEC codes (specifically EZNEC).  NEC antenna modeling is not perfect but if you stay within the constraints it can produce qualitatively useful results.   As with all such models, quantitative results are highly dependent on many factors including geometry, signal quality, and many more.   Hopefully these will be of use - particularly if the loops are in a spherical chicken in a vacuum.

I modeled three sizes of antenna 1/2, 1, and 2 wavelength circumference, at three different heights - 1/4, 1/2 and 1 wavelength.   Also modeled each of these configurations for loops both parallel to and normal to their ground plane.

Sorry for how long this took - as some of you know I have been in the process of retiring and unfortunately this exercise mostly had to take place late in evening after all other boring but necessary stuff had been done.  I am now free and hope to start detailed planning for my own DIY experiments soon.

Herman
Simply beautiful! This was on my bucket list! Love it.

I'm wanting to do a 1/10 loop to see what the patterns are.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 08/28/2015 08:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420734#msg1420734">Quote from: X_RaY on 08/28/2015 05:54 PM</a>
Interesting news:
http://arxiv.org/pdf/1506.08614v1.pdf
LHC confirms measurements of branching fraction ratio of tau-leptons at BaBar and Belle.

" This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the Standard Model."

Maybe there is really a "new, unknown kind of physics"  in addition to the standard model ::)

This plus the recent paper about the sneaky way electrons hide part of their fields both are new to the standard model.

Speculation:  if an electron hides part of it's fields that way it indicates there might be a way to bend the rules of physics with it in useful ways by hiding other stuff the way the electron and other leptons do.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/28/2015 08:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420775#msg1420775">Quote from: rfmwguy on 08/28/2015 07:56 PM</a>
OK, ready to change test setup a bit after much thought and planning.

Three words: Laser Displacement Sensor

Basically mount the sensor under the opposite end to NSF-1701 and measure displacement of end of balance beam. This is a non-contact, triangulation-based micrometer measuring system typically used to measure surface mount component height in pick and place assemblies.

The data rates are overkill for what we're trying to measure, but it could be translated into a nice chart or data set.

Now, here's the bad news...too expensive for a unique-use home budget. Best I ask for a loaner or donation, but am convinced this is the way to go; avoiding long throw lasers, mirrors and targets.

Others have made some of these suggestions-  Use a narror beam HeNe laser mounted against the back wall of your garage.   Mount a flat first surface mirror on the far end of the balance (where the laser pointer was mounted) and another flat first surface mirror above and behind the HeNe laser.   Now comes the hard part: adjust the mirror angles so there is a vertical line of laser dots on each mirror, bringing the dots as close together as possible.    Since the laser beam is bouncing back and forth multiple times any movement of the balance arm will be amplified and readily observable by the seperation of the laser dots.  A lot depends on the stability of the balance arm and how close it will return to the earlier rest position.   If you can isolate one dot and position an image sensor or camera with no lens under it that will allow you to make displacement measurements of some accuracy.   Maybe by measuring the PR of the camera to that dot and the others on either side you will be able to identify each dot in the series and so be able to return the balance beam to the same rest position before each test.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/28/2015 08:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420787#msg1420787">Quote from: cbuchner1 on 08/28/2015 08:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420685#msg1420685">Quote from: deltaMass on 08/28/2015 03:50 PM</a>
Which raises the question - if you're behind the Great Firewall of China, can you access NSF?
Or even (given the fact that Chinese are banned by NASA from visiting ISS) does NASA block China access to NSF?

I was able to access the Emdrive threads on NSF from Shanghai via cable modem connection during a 2 week stay with my in-laws. This was in June/July this year. Back to lurker mode for me.

Welcome to the forum cbuchner1 . :)
That's a useful information, so Yang is also able to follow us, if she like.
But there is no answer from her till now and that's the bad news hidden in your post,
although some people try to get contact  :-\

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/28/2015 09:14 PM
@rfmwguy: think like a bat, dude  8)
http://hackaday.com/2014/01/23/lidar-with-leds-for-under-100/
http://www.miniinthebox.com/ultrasonic-sensor-hc-sr04-distance-measuring-module_p903315.html
Just two quick examples of the search space that will now consume your weekend  ;D
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aceshigh on 08/28/2015 09:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420793#msg1420793">Quote from: X_RaY on 08/28/2015 08:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420787#msg1420787">Quote from: cbuchner1 on 08/28/2015 08:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420685#msg1420685">Quote from: deltaMass on 08/28/2015 03:50 PM</a>
Which raises the question - if you're behind the Great Firewall of China, can you access NSF?
Or even (given the fact that Chinese are banned by NASA from visiting ISS) does NASA block China access to NSF?

I was able to access the Emdrive threads on NSF from Shanghai via cable modem connection during a 2 week stay with my in-laws. This was in June/July this year. Back to lurker mode for me.

Welcome to the forum cbuchner1 . :)
That's a useful information, so Yang is also able to follow us, if she like.
But there is no answer from her till now and that's the bad news hidden in your post,
although some people try to get contact  :-\

being able to follow us obviously doesnt mean she is allowed to post. Hell, even Paul March won´t post here anymore, nor NASA is making it easy to contact him or Dr. White after the whole press (a lot of it too sensationalist and the more scientific press too negative) surround ME and Warp months ago...

well, this thread is getting lots of pages per week in the last months, so I may have missed some Paul March post, but I guess Eagleworks people have been silent since then, right?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: abuzuzu on 08/28/2015 09:54 PM
I'm a RF microwave engineer who has been lurking here for a while.

I note RFguy found a laser displacement sensor that he feels is ideal for measuring DUT movement all but for the cost.

Has anybody considered using a capacitive displacement sensor?  Analog Devices IIRC makes a capacity displacement ic sensor and Linear technology has published several capacitive displacement sensor circuits in there application notes, one IIRC authored by Jim Williams.

These will work in a vacuum if need be.  The basic sensing technology is low power so ic heat management should be- well- manageable.

If anyone is interested in capacitive displacement sensing and unable to find useful information with google, you are welcome to contact me and I'll find the references I have in mind.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 08/28/2015 09:58 PM
Two points:

Rfmwguy's first data set shows signs of patterns in the output of a similar frequency to the cycling of the magnetron (at least to my eye). Fourier analysis on the de-trended signal (postulating a thermal ramp) might show correlation with the magnetron power cycling. If I had some kind of time series of nominal spot centre positions as numbers, I could give this a go. (This is one reason why cycling the power isn't always necessarily a bad thing).

I have to disagree with Dr. Rodal's conclusion that the likely effect is small, at least from one respect.
Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/28/2015 10:27 PM
Ironically there is a unit set up to do 5MW pulses that can adjust frequency within 10MHz of 930MHz ( frustum dimensions would not have to be exact that we could find resonance). At 10 microseconds the cooling of the frustum is managable without online cooling. Issue is would you see something in 10microseconds? Such a test hopefully could produce results that are an order of magnitude above background (into the ground no buoyant effects) or allow other phenomena (photon thruster leakage?) to be measurable. This will probably be experiment one as it is relatively cheap. If it's CoM I expect to see something on a digital scale within those 10us.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/28/2015 11:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420716#msg1420716">Quote from: CraigPichach on 08/28/2015 05:17 PM</a>
We are considering doing two experiments with an industrial magnetron transmitter  (c/w waveguide launcher, isolator and waterload) and the University of Saskatoon; either a 100kW continuous into a copper frustrum 932Hz at TE012 (designing cooling system now..) or 5MW 10microsecond pulses. Looks like we would also try having the magnetron fire into the small base or the big base, maybe some with ports on the side. Have some ANSYS modelling going down now. We would also fire the unit towards the ground that buoyant effects are not in play (I don't know why anyone would aim to produce thrust in the up position right now since hot air rising / buoyant is probably the #1 explanation for positive tests). Objective would be to produce a non-null result an order of magnitude above background.

Good news! Will you use flat or spherical ends on this bigger frustum?
At such high power levels, I wonder if a hollow copper hull could be designed, the interstice being filled with liquid N2 for active cooling, with longer stady-state duration and Q increase.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/28/2015 11:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420796#msg1420796">Quote from: deltaMass on 08/28/2015 09:14 PM</a>
@rfmwguy: think like a bat, dude  8)
http://hackaday.com/2014/01/23/lidar-with-leds-for-under-100/
http://www.miniinthebox.com/ultrasonic-sensor-hc-sr04-distance-measuring-module_p903315.html
Just two quick examples of the search space that will now consume your weekend  ;D
Docs missing on lidar and ultrasonic not enough res...good thoughts tho. Triangulated laser modules are micrometer Res. Far more than I need, but am really itching to write some labview app. Can have it mark times, display motion and remotely turn on maggy. Get real ambitious and record temp, humidity, and video from cam. Labview is a workhorse on a laptop and most sensors are cheap.

Cheap enough except for the cheeky LDS.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 08/29/2015 12:11 AM
Thought for today during coffee...
NSF1701 vents
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/29/2015 12:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420834#msg1420834">Quote from: Silversheep2011 on 08/29/2015 12:11 AM</a>
Thought for today during coffee...
NSF1701 vents

Rfmwguy has measured the temperature repeatedly and posted the results.  What gets hottest by far is the magnetron itself, not the truncated cone. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RAID_RONIN on 08/29/2015 12:41 AM
OMG moment at Phys.org.
New article advising of a new Theory on radiationless states of atoms and why orbiting electrons don't radiate.

http://phys.org/news/2015-08-theory-radiationless-revolution.html
I think this might be a sleeper discovery with interesting applications.

Think Cherenkov radiation and either how to disperse it or hide it....
From the article;
Dr Miroshnichenko, in collaboration with colleagues from Germany and Singapore, successfully tested his new theory with a single silicon nanodiscs between 160 and 310 nanometres in diameter and 50 nanometres high, which he was able to make effectively invisible by cancelling the disc's scattering of visible light.

I could also be thinking way to much into this.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/29/2015 12:51 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>
Two points:

Rfmwguy's first data set shows signs of patterns in the output of a similar frequency to the cycling of the magnetron (at least to my eye). Fourier analysis on the de-trended signal (postulating a thermal ramp) might show correlation with the magnetron power cycling. If I had some kind of time series of nominal spot centre positions as numbers, I could give this a go. (This is one reason why cycling the power isn't always necessarily a bad thing).

I have to disagree with Dr. Rodal's conclusion that the likely effect is small, at least from one respect.
Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

1) Please don't state that you disagree with someone without providing an actual quotation of precisely what you disagree with.  I made a "big picture" assessment referring to several tests, not just Rfmwguy's.

What I wrote was:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
...

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results, for example:  Mulletron's experiment who deserves to be recognized as the true leader in these Do-It-Yourself experiments, had null results documented in early threads, also the experiments with the experimenter that had constant cross-section waveguide and was using dielectric inserts, gave null results.

I understand that null results in these experiments don't close the book, as any experiment is limited on what can be tested (type of force measurement, set-up, etc.), but as Shell, says, "there is no bad data" and we should not forget those null results as well, as they are part of the big picture.

The big picture that is emerging is that if there is any EM Drive force (yes, it may be zero), its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

The force/InputPower reported by Iulian Berca was similar to the one reported by NASA.

2) The statement I made was in reference to the big picture of several experiments.  You have out of context, without providing a quotation, subsumed my statement as if it would be solely based on rfmwguy's experiment.

3) The statement that nobody up to this date has been able to reproduce the thrust/InputPower reported by Shawyer and by Yang is an undeniably correct statement, that stands on its own.

4) Rfmwguy didn't just blindly conduct the test without having any idea of calculated thrust.  Actually discussions were made in the thread of the ability of the teeter totter measurement to measure given levels of thrust. Furthermore anyone can calculate the thrust based on existing formulas.  Thrust (per a given value of Q) can be calculated using Shawyer, McCulloch (he has several formulas) and Notsosureofit's formulas for example.  The geometry was provided by Rfmwguy.

5) It is incorrect that <<denominator of thrust/power in the test are largely unknown>> the denominator: the InputPower is known.   Most assuredly RFMWGUY did not conduct a test blindly without knowledge of the input power.  Rfmwguy even conducted careful tests at different power settings and measured the temperatures, much prior to this actual test.

6) I and others have (previous to your post) discussed that the experimental Q for this experiment is unknown. However, I have calculated the mode shape and the Q at 2.45 GHz for the designed geometry.  Furthermore Q's for other tests have been posted by EM Drive researchers: by NASA and by Shawyer.   If the Q were similar to those reported by NASA or Shawyer, or if the Q would be the one calculated for this mode shape and dimensions, and if the response were proportional to Q (as assumed by Shawyer, McCuloch and Notsosureofit) the response should be significantly larger than the measured response.   One can also calculate how small the Q needs to be in order for the response (for the known power input) to be outside the limits of this measurement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/29/2015 01:01 AM
Some new .csv files uploaded to Google drive. A few .png views also.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxWjlORHBtazE5bW5zR0NHbXJzVU5QTHpHM1U1aXVoYzZkazRwUlpNaW8&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxWjlORHBtazE5bW5zR0NHbXJzVU5QTHpHM1U1aXVoYzZkazRwUlpNaW8&usp=sharing)

This is SeeShell's Crazy Eddie model 2, revision 6. The revisions are the result of changing the antenna configuration. We were assured that this cavity geometry would resonate, and it does resonate very well. It was just surprisingly difficult to find an antenna configuration that excited a resonance mode. The mode that did finally excite is hard to identify, perhaps Dr. Rodal or other experts here will be able to nail it down. It was hoped that the cavity would resonate at 2.47 GHz, and the final calculated resonant frequency was 2.50 GHz, well within the 3% error bounds on Harminv.

Some of you may recall that back in April we did considerable work to nail down the errors in Harminv resonant frequency calculation. Dr. Dominic, who is an experienced meep user helped (did most of the work) to determine this. I, on the other hand, had forgotten about that effort until recently.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 08/29/2015 01:25 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420842#msg1420842">Quote from: Rodal on 08/29/2015 12:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>

...

Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

...

4) It is incorrect that <<denominator of thrust/power in the test are largely unknown>> the denominator: the InputPower is known.   Most assuredly RFMWGUY did not conduct a test blindly without knowledge of the input power.  Rfmwguy even conducted careful tests at different power settings and measured the temperatures, much prior to this actual test.
...

Hi Dr. Rodal,

My interpretation of Rert's comments was that knowledge of raw magnetron InputPower is insufficient to define a denominator in the thrust/power equation.  Unless I missed some critical information within this thread (quite possible), I don't think we know the impedance match between the magnetron and the frustum, and therefore don't know how much of the InputPower is actually getting coupled.

Do we currently have any way of determining reflected vs delivered power during rfmwguy's tests?

Admittedly I also don't know if reflected vs delivered power makes any difference in "thrust"....  but given the Meep analysis so far being based upon delivered power to the frustum, I don't think I'm going to far out on a limb here with Rert.   ;)

If I recall, TT has been nudging rfmwguy to insert a small antenna of some kind to at least allow for some crude S11 analysis and potential real-time monitoring with a cheap VNA during a power-on test.  If rfmwguy could follow SeeShell's lead with a GoFundMe URL, maybe the collective NSF lurkers (such as myself) could help send some pocket change his way to help fund things like a cheap USB VNA.   ;D

Thanks,
James

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/29/2015 01:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420849#msg1420849">Quote from: jmossman on 08/29/2015 01:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420842#msg1420842">Quote from: Rodal on 08/29/2015 12:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>

...

Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

...

4) It is incorrect that <<denominator of thrust/power in the test are largely unknown>> the denominator: the InputPower is known.   Most assuredly RFMWGUY did not conduct a test blindly without knowledge of the input power.  Rfmwguy even conducted careful tests at different power settings and measured the temperatures, much prior to this actual test.
...

Hi Dr. Rodal,

My interpretation of Rert's comments was that knowledge of raw magnetron InputPower is insufficient to define a denominator in the thrust/power equation.  Unless I missed some critical information within this thread (quite possible), I don't think we know the impedance match between the magnetron and the frustum, and therefore don't know how much of the InputPower is actually getting coupled.

Do we currently have any way of determining reflected vs delivered power during rfmwguy's tests?

Admittedly I also don't know if reflected vs delivered power makes any difference in &quoquot;thrust"....  but given the Meep analysis so far being based upon delivered power to the frustum, I don't think I'm going to far out on a limb here with Rert.   ;)

If I recall, TT has been nudging rfmwguy to insert a small antenna of some kind to at least allow for some crude S11 analysis and potential real-time monitoring with a cheap VNA during a power-on test.  If rfmwguy could follow SeeShell's lead with a GoFundMe URL, maybe the collective NSF lurkers (such as myself) could help send some pocket change his way to help fund things like a cheap USB VNA.   ;D

Thanks,
James

We don't have knowledge of "impedance match between the magnetron and the frustum" for most reported experiments, do we?.

Can you point out what numbers of force/InputPower reported in the EM Drive Wiki Experimental results have been calculated based on "impedance match between the magnetron and the frustum" and which ones have used the raw input power? ???

If the numerical force/InputPower reported in the EM Drive Wiki Experimental Results are calculated for the power consumed by the RF Feed, then what is good for the goose is also good for the gander :) .  The raw input power should also be used for rfmwguy's experiment, just as it has been done for most other experiments.

Why should this impedance matching correction become all of a sudden a roadblock for calculation of this parameter for rfmwguy's experiment, when it was not a roadblock for other experiments? ???

For example, just to cite one example, I'm sure there was no "impedance matching correction" made for Iulian Berca's quoted numbers in the EM Drive wiki.  The force/InputPower for Iulian Berca's experiment is based on the raw input power of 800 watts.

Why should "impedance matching correction" be all of a sudden necessary for rfmwguy's and not for Iulian Berca's experiment? ???

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 08/29/2015 01:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420810#msg1420810">Quote from: CraigPichach on 08/28/2015 10:27 PM</a>
Ironically there is a unit set up to do 5MW pulses that can adjust frequency within 10MHz of 930MHz ( frustum dimensions would not have to be exact that we could find resonance). At 10 microseconds the cooling of the frustum is managable without online cooling. Issue is would you see something in 10microseconds? Such a test hopefully could produce results that are an order of magnitude above background (into the ground no buoyant effects) or allow other phenomena (photon thruster leakage?) to be measurable. This will probably be experiment one as it is relatively cheap. If it's CoM I expect to see something on a digital scale within those 10us.

It's the duty cycle that matters in this case.   If the 10 uS pulse happens once a Sec. you have a duty cycle of  .001% and a time averaged power of 50 Watts, which is close to the power level the NASA team used.   Because the mass you are trying to move is so much larger you would see less EM-Drive thrust (if it really exists) but you would also get more thermal, magnetic, and electrostatic effects.   All of the EM-Drive "thrust" signatures disclosed so far have large time constants.   So the effect of each individual 5 MW pulse would not be observable.   This is just my opinion.  I haven't done any EM-Drive experiments.  I have been told I will soon be eating my words.   I am still waiting...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/29/2015 02:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420804#msg1420804">Quote from: abuzuzu on 08/28/2015 09:54 PM</a>
I'm a RF microwave engineer who has been lurking here for a while.

I note RFguy found a laser displacement sensor that he feels is ideal for measuring DUT movement all but for the cost.

Has anybody considered using a capacitive displacement sensor?  Analog Devices IIRC makes a capacity displacement ic sensor and Linear technology has published several capacitive displacement sensor circuits in there application notes, one IIRC authored by Jim Williams.

These will work in a vacuum if need be.  The basic sensing technology is low power so ic heat management should be- well- manageable.

If anyone is interested in capacitive displacement sensing and unable to find useful information with google, you are welcome to contact me and I'll find the references I have in mind.
Thanks, I saw these but was uncertain if I could achieve 0.01 mm resolution at a distance of about 30 mm

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/29/2015 02:12 AM
@Rfmwguy,

Kudos for your heroic efforts.

If I may add to the other comments to improve the set up and results, I think you should look closely into the problem of the pivot(s) of what is hanging on the rigid beam, mainly the frustum at one end, and also something (a kind of rod ?) the other end (with other clamped counter weights). While cheap balances offer only a poor ring "rolling" in hook to hang the balance pans, precision balance use the same kind of knife edge pivot to support the hanging weights both ends as for the central pivot, see in blue :
(balance.jpg)
( bigger (balance.png), source (http://glossary.periodni.com/dictionary.php?en=equal-arm+balance) )

Notice the 3 pivots, each one a knife-edge pivot. Not requiring that you go for agate, but consider that the same care should be taken for the end pivots as for the central one. Any friction/stiction at a pivot linking a hanging weight to the beam could likely affect your results almost as bad as if it were at the central one (that supports the beam).

Also, since you want a greater sensibility, this can be achieved by purely mechanical means by allowing greater angular deviation of beam for a given force : balance has "just" to be tuned nearer to metastable equilibrium by raising the overall centre of mass. Obviously for hanging weights (assuming good pivot) this is the height of the pivots that counts. The balance can in principle be made arbitrarily sensible, to the point the weight of a single eyelash could make it tip-over, by approaching this CoM height to the height of the main central pivot. This increased sensibility is at the cost of slower dynamics and increased risk of instability (making hard to tune for a stable initial rest equilibrium for instance).

From this old book (http://users.humboldt.edu/rpaselk/MuseumProject/Instruments/UseCareBal/UseCareBal.htm) for example (The use and care of a balance, Peter J. Krayer) there is a chapter about sensibility, discussing the relative height of center knife-edge relative to end ones :
(Fig1-3.jpg)

Height of end knife edges are precisely tunable :
(Fig6.jpg)
(Fig18.jpg)

Your set up is not an equal-arm balance but I think the same care should be taken for pivots supporting weights hanging from the beam, and vertical weight placement overall (for weights clamped to the beam). And I second SeeShell on the potential problems of mutual edge dents with the 3 knives pivot design(*). One knife on flat surface, larger area on the linear contact to spread the load means less extension orthogonal to the axis of rotation, assuming the contact can really be made along the edge. For the flat surface I'm thinking about hardened steel or ceramic gauge blocks, for instance (http://www.digital-caliper.co.uk/product_info.php?cPath=53_62_89&products_id=501)...

(*) Rough back of the envelope check indicates .01 mm² contact to support around 10kg weight on hardened steel (martensite, 1000 Vicker hardness, i.e. 1000 kgf/mm²), that is about .1mm span for "point contact". With 10kgf at .025mm (offset of support force application point when "rolling", spread on two contact points) needs to be overcome the equivalent torque of 250mgf (milligram force) at 1m. That is (very roughly) in the ballpark of the measured forces. Sorry this is not fully justified nor properly phrased, just musing around with numbers. Anyway, one blade on two blades sounds not good for heavy loads. Follow the ancients.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/29/2015 02:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420851#msg1420851">Quote from: Rodal on 08/29/2015 01:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420849#msg1420849">Quote from: jmossman on 08/29/2015 01:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420842#msg1420842">Quote from: Rodal on 08/29/2015 12:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>

...

Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

...

4) It is incorrect that <<denominator of thrust/power in the test are largely unknown>> the denominator: the InputPower is known.   Most assuredly RFMWGUY did not conduct a test blindly without knowledge of the input power.  Rfmwguy even conducted careful tests at different power settings and measured the temperatures, much prior to this actual test.
...

Hi Dr. Rodal,

My interpretation of Rert's comments was that knowledge of raw magnetron InputPower is insufficient to define a denominator in the thrust/power equation.  Unless I missed some critical information within this thread (quite possible), I don't think we know the impedance match between the magnetron and the frustum, and therefore don't know how much of the InputPower is actually getting coupled.

Do we currently have any way of determining reflected vs delivered power during rfmwguy's tests?

Admittedly I also don't know if reflected vs delivered power makes any difference in "thrust"....  but given the Meep analysis so far being based upon delivered power to the frustum, I don't think I'm going to far out on a limb here with Rert.   ;)

If I recall, TT has been nudging rfmwguy to insert a small antenna of some kind to at least allow for some crude S11 analysis and potential real-time monitoring with a cheap VNA during a power-on test.  If rfmwguy could follow SeeShell's lead with a GoFundMe URL, maybe the collective NSF lurkers (such as myself) could help send some pocket change his way to help fund things like a cheap USB VNA.   ;D

Thanks,
James

We don't have knowledge of "impedance match between the magnetron and the frustum" for most reported experiments, do we?.

Can you point out what numbers of force/InputPower reported in the EM Drive Wiki Experimental results have been calculated based on "impedance match between the magnetron and the frustum" and which ones have used the raw input power? ???

If the numerical force/InputPower reported in the EM Drive Wiki Experimental Results are calculated for the power consumed by the RF Feed, then what is good for the goose is also good for the gander :) .  The raw input power should also be used for rfmwguy's experiment, just as it has been done for most other experiments.

Why should this impedance matching correction become all of a sudden a roadblock for calculation of this parameter for rfmwguy's experiment, when it was not a roadblock for other experiments? ???

For example, just to cite one example, I'm sure there was no "impedance matching correction" made for Iulian Berca's quoted numbers in the EM Drive wiki.  The force/InputPower for Iulian Berca's experiment is based on the raw input power of 800 watts.

Why should "impedance matching correction" be all of a sudden necessary for rfmwguy's and not for Iulian Berca's experiment? ???
Every time you put food in a microwave, standing waves are made variable by either a rotating base or rotating deflector from the top. Mostly rotating base. The magnetron is fairly impervious to changes in standing waves, only when there are none does it overheat.

I have been using core temp of the tube as a guide for matching. In none of my tests has it exceeded 200 deg C, which Tajmar reported. The heatsink thermal fuse is 160 deg C.

Until we understand the possible effects, I am not overly concerned about match or Q. In fact, I am suspicious of Q ratings so high that thrust values reported by yang/shawyer may be only predictive, not actual.

Regardless, I am on the road to fine resolution of movement, as the laser and target just are not good enough for me. I want to see 0.01 mm resolution in chart graph form, tagged with magnetron on/off. Its an expensive proposition, but for now, I am leaving formulas involving Q out of consideration.

Should I measure real force, I will stop the experiment and take it to a shop with a VNA and measure Q as a single port measurement (much to my dislike).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/29/2015 03:48 AM
Something for those interested in virtual particles from.  Some interesting comments.

https://news.ycombinator.com/item?id=10133829
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/29/2015 04:07 AM
OK, I've concluded that something unusual occurred, not during the initial 5 minute, 30% cycle, but at the 1 minute, 100% cycle.

Once the magnetron has warmed and settled in its "lifted" state, the 1 minute test began. Unlike in the other tests, there is approximately 15 seconds of downward frustum movement, as indicated by a rise in the laser trace in the pic below. The pic is the 1 minute complete test. Thanks to Croppa I believe, I clipped it and enhanced it in Gimp.

There was never a frustum drop in any previous tests until the 1 min FT #2 once the mag came up to temperature and lift was stabilized.

This is where I will focus my efforts, trying to gain higher resolution of this apparent 15 second downward force after warmup. I will see if I can duplicate it with much higher resolution maintaining the current frustum configuration of big base up, small base down, mag on big base.

I consider this an anomaly from previous tests and I cannot easily explain the frustum drop immediately after power on. If there is something to this EM Engine, I believe I will find it in this region.

p.s. The unedited, original montague pic is below my enhanced pic.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/29/2015 05:31 AM
The stickiness in rmfguy’s results have been bothering me.  The thing remains stuck on the same spot from power off at 9:27 to the end of the video.  The frustum is a big copper heatsink with decent airflow.  It should cool quickly, except for the magnetron that has airflow issues.  After making a couple math mistakes because it was late at night, I went and did up a spreadsheet for finding thermal lift from hot air in a cavity with dimensions in inches or centimeters.   

Letting the computer do the thinking for me (and assuming that I didn’t make an error making it) and with an air temperature of around 160C  I get:

(chamber size)    (expected lift)

2 inch cube   60.62   mg
3 inch cube   204.59   mg
4 inch cube   484.96   mg

If rfmguy’s magnetron has a 4 inch cube for a heatsink, then the results are pretty much explained right there (throw in a little bit more thermal lift and you’re good to go). 

What are the dimensions of the magnetron housing on NSF-1701?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/29/2015 06:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>
Two points:

Rfmwguy's first data set shows signs of patterns in the output of a similar frequency to the cycling of the magnetron (at least to my eye). Fourier analysis on the de-trended signal (postulating a thermal ramp) might show correlation with the magnetron power cycling. If I had some kind of time series of nominal spot centre positions as numbers, I could give this a go. (This is one reason why cycling the power isn't always necessarily a bad thing).

I have to disagree with Dr. Rodal's conclusion that the likely effect is small, at least from one respect.
Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

Whilst it may be unwise to do too much analysis of a video such as this, I'm doing it anyway  ;D I was also intrigued by the pattern in the low power run of the first test. I used Fiji (imagej) TrackMate plugin to automatically track the centre of the spot. Here's a movie of how that looks (this is 60 fps so 15x realtime speed). The stepping during the 30% cycles seems quite clear. I'm attaching a file which contains the TrackMate data in case it's of use. Note that the Y position is increasing because the origin of the image is at the top left in ImageJ (also the Time value should be multiplied by 0.25).

Again, I realise there are multiple potential sources of error in this, but it's what we have right now. The improvements being planned by rfmwguy sound fantastic and tracking with high resolution should help to clear up what kind of effects we're really seeing and although the cycling on/off has some advantages, it muddies the waters somewhat since we have to guess what the magnetron's doing based on how it sounds. Having remotely triggered, full power runs with good spatial resolution would be perfect.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/29/2015 07:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420878#msg1420878">Quote from: rfmwguy on 08/29/2015 04:07 AM</a>
OK, I've concluded that something unusual occurred, not during the initial 5 minute, 30% cycle, but at the 1 minute, 100% cycle.

Once the magnetron has warmed and settled in its "lifted" state, the 1 minute test began. Unlike in the other tests, there is approximately 15 seconds of downward frustum movement, as indicated by a rise in the laser trace in the pic below. The pic is the 1 minute complete test. Thanks to Croppa I believe, I clipped it and enhanced it in Gimp.

...
That one was mine, and the same downward deflection that I had indicated. Attached is a higher framerate capture of that portion (~15fps).

What I'm not sure about is whether there may have already been a bit of a downward movement due to air currents (your exiting the room) when the magnetron started.

For the record, I don't believe that you necessarily need to improve your measurement methods yet. Look at the attached image. That's resolving force on the magnitude of air currents in a mostly still room. That's pretty damn good.

It might suffice just to minimize air currents - as someone else mentioned, easiest solution would be to rig up a way to trigger the microwave remotely after the balance has settled.

[Edit] Though you'd also probably want a higher res camera (or higher res copy of the video), with a closer shot on the laser point.

[Edit*] In fact, I'd like to point out that for the time being there's no need to get the frustum setup in the shot, and it's hurting the ability to collect the real, important, data from the laser movement. You could just take a close-up of the laser on the paper so that we have maximum visual resolution of the movement, and save videos of the frustum movement for the critics later. This is experimental observation, and we trust you not to go touch the balance beam. 8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/29/2015 09:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420893#msg1420893">Quote from: Croppa on 08/29/2015 06:43 AM</a>
Whilst it may be unwise to do too much analysis of a video such as this, I'm doing it anyway  ;D I was also intrigued by the pattern in the low power run of the first test. I used Fiji (imagej) TrackMate plugin to automatically track the centre of the spot. Here's a movie of how that looks (this is 60 fps so 15x realtime speed). The stepping during the 30% cycles seems quite clear. I'm attaching a file which contains the TrackMate data in case it's of use. Note that the Y position is increasing because the origin of the image is at the top left in ImageJ (also the Time value should be multiplied by 0.25).

Again, I realise there are multiple potential sources of error in this, but it's what we have right now. The improvements being planned by rfmwguy sound fantastic and tracking with high resolution should help to clear up what kind of effects we're really seeing and although the cycling on/off has some advantages, it muddies the waters somewhat since we have to guess what the magnetron's doing based on how it sounds. Having remotely triggered, full power runs with good spatial resolution would be perfect.
This is brilliant! I've done the same with the flight 2 data. Note the area of interest -- the more I look at it, the more it looks like a downward thrust signature...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 08/29/2015 09:49 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420780#msg1420780">Quote from: SeeShells on 08/28/2015 08:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420761#msg1420761">Quote from: graybeardsyseng on 08/28/2015 07:18 PM</a>
I finally finished the loop antenna modeling exercise.  Not sure if this is still useful but I will post here.   Likely the patterns are the most useful part - as they should give some idea of what modes can be stimulated.   

These models and results are made using a version of the NEC codes (specifically EZNEC).  NEC antenna modeling is not perfect but if you stay within the constraints it can produce qualitatively useful results.   As with all such models, quantitative results are highly dependent on many factors including geometry, signal quality, and many more.   Hopefully these will be of use - particularly if the loops are in a spherical chicken in a vacuum.

I modeled three sizes of antenna 1/2, 1, and 2 wavelength circumference, at three different heights - 1/4, 1/2 and 1 wavelength.   Also modeled each of these configurations for loops both parallel to and normal to their ground plane.

Sorry for how long this took - as some of you know I have been in the process of retiring and unfortunately this exercise mostly had to take place late in evening after all other boring but necessary stuff had been done.  I am now free and hope to start detailed planning for my own DIY experiments soon.

Herman
Simply beautiful! This was on my bucket list! Love it.

I'm wanting to do a 1/10 loop to see what the patterns are.

I am working on 1/10  loops.   They present some interesting challenges for modeling with NEC at these frequencies and I am still working out all the geometry rules etc for the simulation.   Since our lambda is only about 12 cm these are 1.2 cm loops - pretty small.

I will make a couple of comments on small magnetic loops (generally considered as 1/10 lambda or less). 

The bad news:   1) they generally have VERY tight tuning, i.e. they must be carefully tuned to match the frequency (of the source.   With wide i.e. dirty magnetrons that may be tough to do.   2) Ohmic losses in the radiator tend to swamp the radiation resistance and the overall efficiency is low.  This can be obviated with careful design and construction. I have never built one at microwave freqs so that should be interesting in and of itself.

The good news:  They have very strong directivity and patterns which should make it possible to design the antenna to excite specific modes. 

Personally,  I have had good luck with HF and VHF small transmitting loops as a ham operator - often operating inside hotel rooms while on business travel etc.  I think this is definitely an interesting idea to explore.

Note :  will be exercising the U-Haul motto for the next couple of days ("Adventure in Moving").  Even the laptop will be relegated to the occasional Starbucks or other wifi hotspot so this may take a bit.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/29/2015 01:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420886#msg1420886">Quote from: SteveD on 08/29/2015 05:31 AM</a>
The stickiness in rmfguy’s results have been bothering me.  The thing remains stuck on the same spot from power off at 9:27 to the end of the video.  The frustum is a big copper heatsink with decent airflow.  It should cool quickly, except for the magnetron that has airflow issues.  After making a couple math mistakes because it was late at night, I went and did up a spreadsheet for finding thermal lift from hot air in a cavity with dimensions in inches or centimeters.   

Letting the computer do the thinking for me (and assuming that I didn’t make an error making it) and with an air temperature of around 160C  I get:

(chamber size)    (expected lift)



2 inch cube   60.62   mg
3 inch cube   204.59   mg
4 inch cube   484.96   mg

If rfmguy’s magnetron has a 4 inch cube for a heatsink, then the results are pretty much explained right there (throw in a little bit more thermal lift and you’re good to go). 

What are the dimensions of the magnetron housing on NSF-1701?

my calculations don't quite agree with yours

My formula:  Lift = V* (P/2.87)*((1/Tamb)-(1/Tenv))

Lift = kg
V = volume (m^3)
P = pressure (hPA)
Tamb = ambient temperature (K)
Tenv = envelope temperature (K)

assume sea level then P = 1013.25
assume ambient at 60 F = 288 K
assume envelope at 160 C = 433K

2 inch cube = .000065 cubic meters
3 inch cube = .000147 cubic meters
4 inch cube = .000262 cubic meters

Then unless I screwed up

2 inch lift = .027 mg
3 inch lift = .061 mg
4 inch lift = .107 mg

I'm sure we used different constants for ambient temp & pressure, but it looks like one of us is of by a factor of 1,000.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/29/2015 02:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420845#msg1420845">Quote from: aero on 08/29/2015 01:01 AM</a>
Some new .csv files uploaded to Google drive. A few .png views also.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxWjlORHBtazE5bW5zR0NHbXJzVU5QTHpHM1U1aXVoYzZkazRwUlpNaW8&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxWjlORHBtazE5bW5zR0NHbXJzVU5QTHpHM1U1aXVoYzZkazRwUlpNaW8&usp=sharing)

This is SeeShell's Crazy Eddie model 2, revision 6. The revisions are the result of changing the antenna configuration. We were assured that this cavity geometry would resonate, and it does resonate very well. It was just surprisingly difficult to find an antenna configuration that excited a resonance mode. The mode that did finally excite is hard to identify, perhaps Dr. Rodal or other experts here will be able to nail it down. It was hoped that the cavity would resonate at 2.47 GHz, and the final calculated resonant frequency was 2.50 GHz, well within the 3% error bounds on Harminv.

Some of you may recall that back in April we did considerable work to nail down the errors in Harminv resonant frequency calculation. Dr. Dominic, who is an experienced meep user helped (did most of the work) to determine this. I, on the other hand, had forgotten about that effort until recently.
Strange mode pattern. I think the reason for the interesting modes aero is the antenna's are in phase and that's not what happens inside of the cavity with the modes. In real testing the antennas would be 180 degrees out of phase by varying the coax lengths to each antenna. Even with loops (square loops are about the same patterns).

Look at the attached png file and the profiles. They are in phase and being in phase they will not couple with the modes correctly.

This has been an issue with meep in how to reverse the phases on an antenna inside of the frustum. Open for ideas here on how to make meep flip phases.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/29/2015 02:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420893#msg1420893">Quote from: Croppa on 08/29/2015 06:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>
Two points:

Rfmwguy's first data set shows signs of patterns in the output of a similar frequency to the cycling of the magnetron (at least to my eye). Fourier analysis on the de-trended signal (postulating a thermal ramp) might show correlation with the magnetron power cycling. If I had some kind of time series of nominal spot centre positions as numbers, I could give this a go. (This is one reason why cycling the power isn't always necessarily a bad thing).

I have to disagree with Dr. Rodal's conclusion that the likely effect is small, at least from one respect.
Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

Whilst it may be unwise to do too much analysis of a video such as this, I'm doing it anyway  ;D I was also intrigued by the pattern in the low power run of the first test. I used Fiji (imagej) TrackMate plugin to automatically track the centre of the spot. Here's a movie of how that looks (this is 60 fps so 15x realtime speed). The stepping during the 30% cycles seems quite clear. I'm attaching a file which contains the TrackMate data in case it's of use. Note that the Y position is increasing because the origin of the image is at the top left in ImageJ (also the Time value should be multiplied by 0.25).

Again, I realise there are multiple potential sources of error in this, but it's what we have right now. The improvements being planned by rfmwguy sound fantastic and tracking with high resolution should help to clear up what kind of effects we're really seeing and although the cycling on/off has some advantages, it muddies the waters somewhat since we have to guess what the magnetron's doing based on how it sounds. Having remotely triggered, full power runs with good spatial resolution would be perfect.

Used the SNR and contrast to calculate the spot SD and replotted.  The SD capture by Spotify is for the whole frame, so that's useless, but the SNR and contrast is for the spot window (radius 25? in your run).

Your curves have low error margins (typically +- 2 pixels at 1 SD).  Error bars do not change the appearance.  Essentially, your data is as it is and accurately depicts the movement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/29/2015 03:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420893#msg1420893">Quote from: Croppa on 08/29/2015 06:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>
Two points:

Rfmwguy's first data set shows signs of patterns in the output of a similar frequency to the cycling of the magnetron (at least to my eye). Fourier analysis on the de-trended signal (postulating a thermal ramp) might show correlation with the magnetron power cycling. If I had some kind of time series of nominal spot centre positions as numbers, I could give this a go. (This is one reason why cycling the power isn't always necessarily a bad thing).

I have to disagree with Dr. Rodal's conclusion that the likely effect is small, at least from one respect.
Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

Whilst it may be unwise to do too much analysis of a video such as this, I'm doing it anyway  ;D I was also intrigued by the pattern in the low power run of the first test. I used Fiji (imagej) TrackMate plugin to automatically track the centre of the spot. Here's a movie of how that looks (this is 60 fps so 15x realtime speed). The stepping during the 30% cycles seems quite clear. I'm attaching a file which contains the TrackMate data in case it's of use. Note that the Y position is increasing because the origin of the image is at the top left in ImageJ (also the Time value should be multiplied by 0.25).

Again, I realise there are multiple potential sources of error in this, but it's what we have right now. The improvements being planned by rfmwguy sound fantastic and tracking with high resolution should help to clear up what kind of effects we're really seeing and although the cycling on/off has some advantages, it muddies the waters somewhat since we have to guess what the magnetron's doing based on how it sounds. Having remotely triggered, full power runs with good spatial resolution would be perfect.

re: your stepping.  I took a subsample of your data from your roughly 300 to 550 corresponding to your data points 1055 through 2291.

A linear fit gave me an R2 of .9885 which is pretty darn good.  The base formula was y = 0.0381x + 50.887

Using my corresponding data points 1 through 1147, the residuals pretty much confirm your observation.

Attached image file

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/29/2015 03:52 PM
All this fantastic data analysis makes me yearn for Flight Test #3  8)

I won't put you all through this again with low res video...I'm going to spring for a laser displacement sensor, amp and computer interface. Trying now to find the best price. It MAY require me to have a small crowdfund or gofund me page just for this equipment since I won't convince my wife that I could use the LDS for anything else around the house...c'mon, ya know how it is  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/29/2015 05:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420942#msg1420942">Quote from: SeeShells on 08/29/2015 02:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420845#msg1420845">Quote from: aero on 08/29/2015 01:01 AM</a>
Some new .csv files uploaded to Google drive. A few .png views also.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxWjlORHBtazE5bW5zR0NHbXJzVU5QTHpHM1U1aXVoYzZkazRwUlpNaW8&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxWjlORHBtazE5bW5zR0NHbXJzVU5QTHpHM1U1aXVoYzZkazRwUlpNaW8&usp=sharing)

This is SeeShell's Crazy Eddie model 2, revision 6. The revisions are the result of changing the antenna configuration. We were assured that this cavity geometry would resonate, and it does resonate very well. It was just surprisingly difficult to find an antenna configuration that excited a resonance mode. The mode that did finally excite is hard to identify, perhaps Dr. Rodal or other experts here will be able to nail it down. It was hoped that the cavity would resonate at 2.47 GHz, and the final calculated resonant frequency was 2.50 GHz, well within the 3% error bounds on Harminv.

Some of you may recall that back in April we did considerable work to nail down the errors in Harminv resonant frequency calculation. Dr. Dominic, who is an experienced meep user helped (did most of the work) to determine this. I, on the other hand, had forgotten about that effort until recently.
Strange mode pattern. I think the reason for the interesting modes aero is the antenna's are in phase and that's not what happens inside of the cavity with the modes. In real testing the antennas would be 180 degrees out of phase by varying the coax lengths to each antenna. Even with loops (square loops are about the same patterns).

Look at the attached png file and the profiles. They are in phase and being in phase they will not couple with the modes correctly.

This has been an issue with meep in how to reverse the phases on an antenna inside of the frustum. Open for ideas here on how to make meep flip phases.

The trouble with Internet collaboration is that all of your warts show. I found this:

Quote
Just use the amplitude property of the source, which is a complex number and can therefore set the phase:

(define gauss (make gaussian-src (frequency f) (fwidth df)))
(set! sources (list (make source (src gauss) (center 0))
                    (make source (src gauss) (center 0)
                                 (amplitude (exp (* 0+1i phi))))))

So I would guess that "phi" above is the phase angle - the input variable - and am speculating that you want it set to pi(), ie. 180 degrees?

Although from the example, I'm not quite sure that the example is doing anything with both sources being point sources at the same location. In any case, I'll give this a try. My sources are neither co-located or point sources.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/29/2015 05:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420904#msg1420904">Quote from: kwertyops on 08/29/2015 09:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420893#msg1420893">Quote from: Croppa on 08/29/2015 06:43 AM</a>
Whilst it may be unwise to do too much analysis of a video such as this, I'm doing it anyway  ;D I was also intrigued by the pattern in the low power run of the first test. I used Fiji (imagej) TrackMate plugin to automatically track the centre of the spot. Here's a movie of how that looks (this is 60 fps so 15x realtime speed). The stepping during the 30% cycles seems quite clear. I'm attaching a file which contains the TrackMate data in case it's of use. Note that the Y position is increasing because the origin of the image is at the top left in ImageJ (also the Time value should be multiplied by 0.25).

Again, I realise there are multiple potential sources of error in this, but it's what we have right now. The improvements being planned by rfmwguy sound fantastic and tracking with high resolution should help to clear up what kind of effects we're really seeing and although the cycling on/off has some advantages, it muddies the waters somewhat since we have to guess what the magnetron's doing based on how it sounds. Having remotely triggered, full power runs with good spatial resolution would be perfect.
This is brilliant! I've done the same with the flight 2 data. Note the area of interest -- the more I look at it, the more it looks like a downward thrust signature...

The on cycle is kicking a bit of hot air out the open side of the heat sink, causing the thermal lift to fall.  Retest from cold at 100% power with at least 15 minutes between runs.  Alternatively,  remove the magnetron. Have it, I don't know maybe feed into a symmetrical cavity that resonates at the frequency you want to hit with the EMDrive, then use an antenna to feed from the symmetrical cavity into the drive (and put the heat source well away from the data collection point, perhaps in a chest freezer).  Or you could just rig up a scale and some way to measure horizontal thrust with the thing on its side.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/29/2015 05:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420937#msg1420937">Quote from: glennfish on 08/29/2015 01:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420886#msg1420886">Quote from: SteveD on 08/29/2015 05:31 AM</a>
The stickiness in rmfguy’s results have been bothering me.  The thing remains stuck on the same spot from power off at 9:27 to the end of the video.  The frustum is a big copper heatsink with decent airflow.  It should cool quickly, except for the magnetron that has airflow issues.  After making a couple math mistakes because it was late at night, I went and did up a spreadsheet for finding thermal lift from hot air in a cavity with dimensions in inches or centimeters.   

Letting the computer do the thinking for me (and assuming that I didn’t make an error making it) and with an air temperature of around 160C  I get:

(chamber size)    (expected lift)



2 inch cube   60.62   mg
3 inch cube   204.59   mg
4 inch cube   484.96   mg

If rfmguy’s magnetron has a 4 inch cube for a heatsink, then the results are pretty much explained right there (throw in a little bit more thermal lift and you’re good to go). 

What are the dimensions of the magnetron housing on NSF-1701?

my calculations don't quite agree with yours

My formula:  Lift = V* (P/2.87)*((1/Tamb)-(1/Tenv))

Lift = kg
V = volume (m^3)
P = pressure (hPA)
Tamb = ambient temperature (K)
Tenv = envelope temperature (K)

assume sea level then P = 1013.25
assume ambient at 60 F = 288 K
assume envelope at 160 C = 433K

2 inch cube = .000065 cubic meters
3 inch cube = .000147 cubic meters
4 inch cube = .000262 cubic meters

Then unless I screwed up

2 inch lift = .027 mg
3 inch lift = .061 mg
4 inch lift = .107 mg

I'm sure we used different constants for ambient temp & pressure, but it looks like one of us is of by a factor of 1,000.

I pulled from here http://www.real-world-physics-problems.com/hot-air-balloon-physics.html (http://www.real-world-physics-problems.com/hot-air-balloon-physics.html).  Rechecking formula.  Sorry it was late.

and edit:
The standard atmosphere (symbol: atm) is a unit of pressure equal to 101325 Pa or 1013.25 hectopascals or millibars. Equivalent to 760 mmHg (torr), 29.92 inHg, 14.696 psi. (The pascal is a newton per square meter or in terms of SI base units, kilogram per meter per second-squared.) 

So should we be using millibars or pascals for that calculation?  The difference, as you point out, is a factor of 1000.  The source I quoted says pascals.  Is it wrong?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/29/2015 05:33 PM
How about this!

First one - new, pi out of phase.
Second one - As it has been.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/29/2015 05:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420955#msg1420955">Quote from: rfmwguy on 08/29/2015 03:52 PM</a>
All this fantastic data analysis makes me yearn for Flight Test #3  8)

I won't put you all through this again with low res video...I'm going to spring for a laser displacement sensor, amp and computer interface. Trying now to find the best price. It MAY require me to have a small crowdfund or gofund me page just for this equipment since I won't convince my wife that I could use the LDS for anything else around the house...c'mon, ya know how it is  ;)
I want reiterate that I don't think you need to do that. Definitely you should if you want, it's your experiment, but I think that just by moving the camera so the video is a close-up on the laser spot, we could get pretty high resolution, reliable data out of that.

A lot of the noise we're seeing looks like thermal air current stuff, and oscillations due to the natural vibration frequency of the balance beam - neither of which would be fixed by upgrading to a new measurement method.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/29/2015 05:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420954#msg1420954">Quote from: glennfish on 08/29/2015 03:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420893#msg1420893">Quote from: Croppa on 08/29/2015 06:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420806#msg1420806">Quote from: RERT on 08/28/2015 09:58 PM</a>
Two points:

Rfmwguy's first data set shows signs of patterns in the output of a similar frequency to the cycling of the magnetron (at least to my eye). Fourier analysis on the de-trended signal (postulating a thermal ramp) might show correlation with the magnetron power cycling. If I had some kind of time series of nominal spot centre positions as numbers, I could give this a go. (This is one reason why cycling the power isn't always necessarily a bad thing).

I have to disagree with Dr. Rodal's conclusion that the likely effect is small, at least from one respect.
Rfmwguy's experiment hasn't yet changed our state of knowledge: Q is completely unknown, as is the mode shape, nor do we yet have any estimate of the actual thrust which has been stated in this thread. Both the numerator and denominator of thrust/power in the test are largely unknown. The effect may indeed be small, but rfmwguy's tests haven't yet affected the assessment of the size of the effect.

R.

Whilst it may be unwise to do too much analysis of a video such as this, I'm doing it anyway  ;D I was also intrigued by the pattern in the low power run of the first test. I used Fiji (imagej) TrackMate plugin to automatically track the centre of the spot. Here's a movie of how that looks (this is 60 fps so 15x realtime speed). The stepping during the 30% cycles seems quite clear. I'm attaching a file which contains the TrackMate data in case it's of use. Note that the Y position is increasing because the origin of the image is at the top left in ImageJ (also the Time value should be multiplied by 0.25).

Again, I realise there are multiple potential sources of error in this, but it's what we have right now. The improvements being planned by rfmwguy sound fantastic and tracking with high resolution should help to clear up what kind of effects we're really seeing and although the cycling on/off has some advantages, it muddies the waters somewhat since we have to guess what the magnetron's doing based on how it sounds. Having remotely triggered, full power runs with good spatial resolution would be perfect.

re: your stepping.  I took a subsample of your data from your roughly 300 to 550 corresponding to your data points 1055 through 2291.

A linear fit gave me an R2 of .9885 which is pretty darn good.  The base formula was y = 0.0381x + 50.887

Using my corresponding data points 1 through 1147, the residuals pretty much confirm your observation.

Attached image file

This is great, especially given that the magnetron was on 12 times during the 300 second cycle. There seems little doubt that there's a correlation there.

As a final way to look at this, I put the audio back into a 2x realtime version of the tracking movie. It may be more hilarious than it is informative (the Barry White tones are now those of a chipmunk) but I couldn't resist posting it. Sorry rfmwguy  8) .

Since I'm taking up bandwidth with diminishing returns, I'll go back to lurking now. Best of luck with the updates to rfmwguy. I for one would be happy to put a few bucks into a crowdfund, especially if it lets me use Paypal  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/29/2015 06:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420988#msg1420988">Quote from: aero on 08/29/2015 05:33 PM</a>
How about this!

First one - new, pi out of phase.
Second one - As it has been.
Yes! Nice work aero! Run it when you can.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/29/2015 08:33 PM
Omron Z4M-W40RA Laser Displacement Sensor on its way...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Kenjee on 08/29/2015 08:52 PM
Works similiar to laser mouse. Maybe its cheaper to hack a mouse?  :-\


Btw congratz!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/29/2015 08:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421028#msg1421028">Quote from: Kenjee on 08/29/2015 08:52 PM</a>
Works similiar to laser mouse. Maybe its cheaper to hack a mouse?  :-\


Btw congratz!
These things are pretty cool, they measure like a micrometer by bouncing a laser off a target and it reflects back at the sensor. I has more accuracy than I need, but talk about being able to see oscillations! I should be able to calibrate exact displacement for a variet of calibrated weights...no more guessing or estimating.

Not sure if any other experiments used something like this or not, but for vertical position changes, its the best I think.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DaCunha on 08/29/2015 09:16 PM
Does anyone know if Eagleworks is continuing to work on EMDrive? If so did they say when news can be expected?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/29/2015 10:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421030#msg1421030">Quote from: rfmwguy on 08/29/2015 08:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421028#msg1421028">Quote from: Kenjee on 08/29/2015 08:52 PM</a>
Works similiar to laser mouse. Maybe its cheaper to hack a mouse?  :-\


Btw congratz!
These things are pretty cool, they measure like a micrometer by bouncing a laser off a target and it reflects back at the sensor. I has more accuracy than I need, but talk about being able to see oscillations! I should be able to calibrate exact displacement for a variet of calibrated weights...no more guessing or estimating.

Not sure if any other experiments used something like this or not, but for vertical position changes, its the best I think.

My I suggest that you run at 50% - 80% power on the MW, for about 10 - 20 minutes, continuously. Because,

1. This will give plenty of time for the air to heat up and the rig to stabilize at a relatively constant air temperature.

2. The cycling will then allow us to tell if there is thrust when it is on and none when it is off, that is not due to hot air.

Contrary to what others have said, I think that given this buoyancy effect we're seeing, having it run continuously at 100% won't show us thrust, because there is no stable baseline to compare it to. Allowing it to cycle on and off AFTER the temperatures have stabilized, will allow us to measure the difference and thereby, the thrust. The data thus far shows that the temperature drift will stabilize after a time.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/29/2015 10:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421057#msg1421057">Quote from: WarpTech on 08/29/2015 10:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421030#msg1421030">Quote from: rfmwguy on 08/29/2015 08:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421028#msg1421028">Quote from: Kenjee on 08/29/2015 08:52 PM</a>
Works similiar to laser mouse. Maybe its cheaper to hack a mouse?  :-\


Btw congratz!
These things are pretty cool, they measure like a micrometer by bouncing a laser off a target and it reflects back at the sensor. I has more accuracy than I need, but talk about being able to see oscillations! I should be able to calibrate exact displacement for a variet of calibrated weights...no more guessing or estimating.

Not sure if any other experiments used something like this or not, but for vertical position changes, its the best I think.

My I suggest that you run at 50% - 80% power on the MW, for about 10 - 20 minutes, continuously. Because,

1. This will give plenty of time for the air to heat up and the rig to stabilize at a relatively constant air temperature.

2. The cycling will then allow us to tell if there is thrust when it is on and none when it is off, that is not due to hot air.

Contrary to what others have said, I think that given this buoyancy effect we're seeing, having it run continuously at 100% won't show us thrust, because there is no stable baseline to compare it to. Allowing it to cycle on and off AFTER the temperatures have stabilized, will allow us to measure the difference and thereby, the thrust. The data thus far shows that the temperature drift will stabilize after a time.
Todd

Instead of running "continuously at 100% power for several minutes", the proposal was to run at 100% constantly for periods of time on (and then off) such that the on and off cycling is completely under control to be whatever one wishes and can  be so controlled at will, as well as identified.  There was discussion to enable such switching to be done remotely, and several people posted how to achieve such remote control.  It was emphasized that several on and off cycles were needed in order to have a statistical basis of comparison.  The main objection was to cyclic running such that the magnetron was only on for 30% of the time.    The proposal to run <<50% - 80% power on the MW>> is better than running at 30%, because the response at the moment is mainly governed by the slow long-term drift that appears to be of a thermal (rather than electromagnetic) nature and we need to increase the signal to noise ratio.  So, yes, if the choice is between 30% or 50%,  50% is preferable to 30% for the above reason.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/29/2015 11:39 PM
Re-uploaded the dual big end stub antenna run for the Crazy-Eddie, Rev. 2 model. During this run, the antennas were 180 degrees out of phase. All else is the same. However, the Harminv calculated resonant frequency was lower, by about 40 kHz, and the calculated quality factor was an order of magnitude less but still an unrealistic 200,000. That tells us that this configuration will resonate, but no more than that. Still, that's good to know.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing)

There are png view files of slice 13 (30 views) along with the Python plot program used to generate them. If there is an expert in plotting with this program, it would be nice if you could take the time needed to provide a different color map. In fact, I think all would prefer contour lines with magnitude labels. Colors are not so important except some colors burn out the eyeball and should be avoided. The plot program is available for download, and more information about it, as well as the original source is available on the emdrive wiki. Thanks.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/29/2015 11:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421072#msg1421072">Quote from: aero on 08/29/2015 11:39 PM</a>
Re-uploaded the dual big end stub antenna run for the Crazy-Eddie, Rev. 2 model. During this run, the antennas were 180 degrees out of phase. All else is the same. However, the Harminv calculated resonant frequency was lower, by about 40 kHz, and the calculated quality factor was an order of magnitude less but still an unrealistic 200,000. That tells us that this configuration will resonate, but no more than that. Still, that's good to know.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing)

There are png view files of slice 13 (30 views) along with the Python plot program used to generate them. If there is an expert in plotting with this program, it would be nice if you could take the time needed to provide a different color map. In fact, I think all would prefer contour lines with magnitude labels. Colors are not so important except some colors burn out the eyeball and should be avoided. The plot program is available for download, and more information about it, as well as the original source is available on the emdrive wiki. Thanks.

Given that previously you were getting Q's of 5 million and sometimes more than 10 million (for other cases, since I do not know what the Q calculated for the previous run was), a Q of 200,000 for this latest run sounds like NOT much resonance in relation to those previously calculated Q's.

Say that the Q of 5 million (with the wrong Drude constants) is equivalent to a Q of 50,000  (if you were to use the right Drude constants) , (a factor of 100 between)  then a Q of 200,000 would be equivalent to a Q of only 2,000 which is not much of a resonance for a theoretical Q.

I don't recognize this mode as a standard cylindrical mode.  It is certainly not TE012.

Given that the electric field in the longitudinal direction Ezx is stronger (in relation to the other electric field components) than the magnetic field in the longitudinal direction Hzx (in relation to the other magnetic field components), this looks like a TM (transverse magnetic) mode for both cases.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/30/2015 01:02 AM
There's something very, very wrong there, as should be obvious.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 01:19 AM
Get ready...am now running NSF-1701 Flight Test 2A

This will be long duration recording of about 30 minutes beginning with a 5 minute duration of 30% power cycle. Reason its 2A is no changes made to engine, only laser target. Vid is closeup of target only. Seems much higher resolution. Overall duration is to monitor lift to see how it settles back after end of power cycle. A 500 mg calibrated weight was added then removed prior to powerup.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Devilstower on 08/30/2015 01:24 AM
@rfmwguy Good deal. I'm glad you gave into the itch to generate more data. There's tantalizing hints in the previous runs — which is pretty emblematic of this whole "field." Anxiously awaiting the video.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 01:27 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 08/30/2015 01:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421091#msg1421091">Quote from: rfmwguy on 08/30/2015 01:19 AM</a>
Get ready...am now running NSF-1701 Flight Test 2A

This will be long duration recording of about 30 minutes beginning with a 5 minute duration of 30% power cycle. Reason its 2A is no changes made to engine, only laser target. Vid is closeup of target only. Seems much higher resolution. Overall duration is to monitor lift to see how it settles back after end of power cycle. A 500 mg calibrated weight was added then removed prior to powerup.

Might I humbly suggest the calibration weight addition/removal following the test also?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 01:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421091#msg1421091">Quote from: rfmwguy on 08/30/2015 01:19 AM</a>
Get ready...am now running NSF-1701 Flight Test 2A

This will be long duration recording of about 30 minutes beginning with a 5 minute duration of 30% power cycle. Reason its 2A is no changes made to engine, only laser target. Vid is closeup of target only. Seems much higher resolution. Overall duration is to monitor lift to see how it settles back after end of power cycle. A 500 mg calibrated weight was added then removed prior to powerup.

Excellent :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/30/2015 01:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421093#msg1421093">Quote from: aero on 08/30/2015 01:27 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.
I'm talking about the software that calculates ridiculously high Q values.
And either dial down the aggression, or get some fresh air and walk it off.
Too many gangster movies?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 02:03 AM
NSF-1701 FT 2A completed and uploading as I type. Sorry, only did weight calibration at beginning. After analysis I can do FT2B with weight calibration at end as well. Interesting I noted less leak detector alarming, but magnetron seemed to come up to temp as normal. After 30 minutes, heatsink was approximately 100 degrees C, ambient around 27 deg C. It may take an hour or so for heatsink to return to ambient.

The laser bars are greatly improved as camera is much closer to back of target. Think everyone's going to like it.

Also, I can set FT2B for 50% power cycle and 5 minutes as I feel comfortable enough that maggy match is pretty good and overtemp is not likely.

These sub-tests are no problem as my car has been banished from my side of the garage and the test stand has taken over for a while  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 02:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421098#msg1421098">Quote from: deltaMass on 08/30/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421093#msg1421093">Quote from: aero on 08/30/2015 01:27 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.
I'm talking about the software that calculates ridiculously high Q values.
And either dial down the aggression, or get some fresh air and walk it off.
Too many gangster movies?
Reading Tom Clancy's "Support and Defend." But I find pot shots in the dark annoying in the best of times.

As for the meat of your comment, the calculated Q values are not very useful as numeric values. I have found though that ridiculously high Q values result in calculated field evolution that clearly leads to resonance while very low to no Q values result in calculated fields that really never evolve to anything discernible. As far as I can tell that is the utility of the calculated Q from this program.

Perhaps you can tell me this - Can these cavity field patterns be considered as Bloch Periodic? I ask because I have MPB installed but have never used it. It is applicable to problems that satisfy Bloch's Theorem.

MPB, also developed at MIT, can be thought of as a sister program to meep, it calculates frequencies and modes using Fourier transforms. I speculate that many meep users avoid Harminv and use MPB instead but have no basis to say that.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/30/2015 03:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421104#msg1421104">Quote from: aero on 08/30/2015 02:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421098#msg1421098">Quote from: deltaMass on 08/30/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421093#msg1421093">Quote from: aero on 08/30/2015 01:27 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.
I'm talking about the software that calculates ridiculously high Q values.
And either dial down the aggression, or get some fresh air and walk it off.
Too many gangster movies?
Reading Tom Clancy's "Support and Defend." But I find pot shots in the dark annoying in the best of times.

As for the meat of your comment, the calculated Q values are not very useful as numeric values. I have found though that ridiculously high Q values result in calculated field evolution that clearly leads to resonance while very low to no Q values result in calculated fields that really never evolve to anything discernible. As far as I can tell that is the utility of the calculated Q from this program.

Perhaps you can tell me this - Can these cavity field patterns be considered as Bloch Periodic? I ask because I have MPB installed but have never used it. It is applicable to problems that satisfy Bloch's Theorem.

MPB, also developed at MIT, can be thought of as a sister program to meep, it calculates frequencies and modes using Fourier transforms. I speculate that many meep users avoid Harminv and use MPB instead but have no basis to say that.
I just finished watching Salt. I regret that you were annoyed. Obviously you identify pretty closely with the code. At least you've shown that the Q value spat out is of qualitative use, even though the absolute value is useless. That's worth knowing.

Many years ago I did a degree which included solid state physics and I recall Bloch. But since I haven't used it since, I've forgotten about it. I'm not your man for that.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 03:34 AM
NSF-1701 FT #2A Video

https://youtu.be/Oq44P8b87L8
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 04:13 AM
Misspoke in video, 500 mg weight simulates downward thrust but lifts laser spot. Thermal lift would be downward movement of laser spot with upwards movement of frustum on balance beam.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 08/30/2015 04:20 AM
rfmwguy
You are best person to ask,  look from about 15:00 -15:50

there is what appears to be a blue light in background moving up and down a bit
doesn't seem that noticeable elsewhere.
What is it do you think it is?
Where is it coming from?

and thankyou for posting -it's quite fun...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 04:34 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421114#msg1421114">Quote from: deltaMass on 08/30/2015 03:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421104#msg1421104">Quote from: aero on 08/30/2015 02:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421098#msg1421098">Quote from: deltaMass on 08/30/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421093#msg1421093">Quote from: aero on 08/30/2015 01:27 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.
I'm talking about the software that calculates ridiculously high Q values.
And either dial down the aggression, or get some fresh air and walk it off.
Too many gangster movies?
Reading Tom Clancy's "Support and Defend." But I find pot shots in the dark annoying in the best of times.

As for the meat of your comment, the calculated Q values are not very useful as numeric values. I have found though that ridiculously high Q values result in calculated field evolution that clearly leads to resonance while very low to no Q values result in calculated fields that really never evolve to anything discernible. As far as I can tell that is the utility of the calculated Q from this program.

Perhaps you can tell me this - Can these cavity field patterns be considered as Bloch Periodic? I ask because I have MPB installed but have never used it. It is applicable to problems that satisfy Bloch's Theorem.

MPB, also developed at MIT, can be thought of as a sister program to meep, it calculates frequencies and modes using Fourier transforms. I speculate that many meep users avoid Harminv and use MPB instead but have no basis to say that.
I just finished watching Salt. I regret that you were annoyed. Obviously you identify pretty closely with the code. At least you've shown that the Q value spat out is of qualitative use, even though the absolute value is useless. That's worth knowing.

Many years ago I did a degree which included solid state physics and I recall Bloch. But since I haven't used it since, I've forgotten about it. I'm not your man for that.

Here is the Harminv definition: Does it make sense to you?

Quote
(harminv-Q result)
    Return dimensionless lifetime, or "quality factor", Q, defined as -\mathrm{Re}\,\omega / 2 \mathrm{Im}\,\omega.
(that is, -Re(w) / 2 Im(w), the negative of the real part of the complex frequency divided by twice the imaginary part)

As I understand things, the frequency should be real so the imaginary part should be tiny and so Q should be huge?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/30/2015 04:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421116#msg1421116">Quote from: rfmwguy on 08/30/2015 03:34 AM</a>
NSF-1701 FT #2A Video

https://youtu.be/Oq44P8b87L8

This is how it looks with the same treatment as before (4 fps, 8x stretched vertically).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/30/2015 04:51 AM
Okay, here's the TrackMate analysis on NSF-1701 #2A.

My interpretation is that this confirms that your knife-edge balance is sticking (see the lack of recovery from when the weight was added, to after it was taken off.

I've included two images:

-One with the full data plot - this would be the one to look at for thrust signatures during the run. To my eye there appears to be either none, or else possibly a downward thrust at the very beginning of the run (it is hard to tell due to lengthy laser obstruction immediately prior to the run)

-Another where I've shrunk the x-axis from the time when the microwave is started until the end - this one makes it easier to see what we're identifying as the thermal lift, and the subsequent recovery. It does appear to go back down after the run is completed, even below its original height

My take on this run as a whole is that it seems to indicate that the knife-edge fulcrum might be a problem, especially in long-term height drift measurement.

However, that doesn't necessarily imply that it's not still useful for short-term thrust measurement.

[Edit] I'm now also attaching the raw data that goes with that plot (whitespace separated values).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/30/2015 06:26 AM
One more, with areas of interest for this flight.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/30/2015 07:02 AM
Does this confirm that the pivot is sticky? - it looks that way.

@aero: The harminv thing makes no sense to me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 09:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421072#msg1421072">Quote from: aero on 08/29/2015 11:39 PM</a>
Re-uploaded the dual big end stub antenna run for the Crazy-Eddie, Rev. 2 model. During this run, the antennas were 180 degrees out of phase. All else is the same. However, the Harminv calculated resonant frequency was lower, by about 40 kHz, and the calculated quality factor was an order of magnitude less but still an unrealistic 200,000. That tells us that this configuration will resonate, but no more than that. Still, that's good to know.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing)

There are png view files of slice 13 (30 views) along with the Python plot program used to generate them. If there is an expert in plotting with this program, it would be nice if you could take the time needed to provide a different color map. In fact, I think all would prefer contour lines with magnitude labels. Colors are not so important except some colors burn out the eyeball and should be avoided. The plot program is available for download, and more information about it, as well as the original source is available on the emdrive wiki. Thanks.

Your first image below showed two dipole antennas 180° out-of-phase and located near the big base and in the middle of the predicted "lower lobes" of TE012 mode. That's a good placement IMHO.

However what we see in the following pictures is the two antennas are stuck on the side walls, like for regular 1/4 λ stub antennas:

https://drive.google.com/file/d/0B1XizxEfB23tUHJOeFpTZkRUc1k/view
https://drive.google.com/file/d/0B1XizxEfB23tWDBTTXpWMkVLOTA/view
https://drive.google.com/file/d/0B1XizxEfB23tQThhUmkzck9xZGM/view
https://drive.google.com/file/d/0B1XizxEfB23tdXZHUTMyekx4eWs/view
https://drive.google.com/file/d/0B1XizxEfB23tWVJLNmI4NzNPQlE/view

So maybe it is the location of the antennas that is not correct. Shouldn't they be located more near the center of axi-symmetry of the cavity, like in the picture below?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 08/30/2015 11:19 AM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421039#msg1421039">Quote from: DaCunha on 08/29/2015 09:16 PM</a>
Does anyone know if Eagleworks is continuing to work on EMDrive? If so did they say when news can be expected?

As no one else answered this. To the best of our knowledge the answers to your questions are respectively yes & no,

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/30/2015 11:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421150#msg1421150">Quote from: flux_capacitor on 08/30/2015 09:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421072#msg1421072">Quote from: aero on 08/29/2015 11:39 PM</a>
Re-uploaded the dual big end stub antenna run for the Crazy-Eddie, Rev. 2 model. During this run, the antennas were 180 degrees out of phase. All else is the same. However, the Harminv calculated resonant frequency was lower, by about 40 kHz, and the calculated quality factor was an order of magnitude less but still an unrealistic 200,000. That tells us that this configuration will resonate, but no more than that. Still, that's good to know.

https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxRU96aGNHWkdPSHM5MmlxNi00NUtkZFdMVllkOU9oV3R6SG55Y2p5Zlk&usp=sharing)

There are png view files of slice 13 (30 views) along with the Python plot program used to generate them. If there is an expert in plotting with this program, it would be nice if you could take the time needed to provide a different color map. In fact, I think all would prefer contour lines with magnitude labels. Colors are not so important except some colors burn out the eyeball and should be avoided. The plot program is available for download, and more information about it, as well as the original source is available on the emdrive wiki. Thanks.

Your first image below showed two dipole antennas 180° out-of-phase and located near the big base and in the middle of the predicted "lower lobes" of TE012 mode. That's a good placement IMHO.

However what we see in the following pictures is the two antennas are stuck on the side walls, like for regular 1/4 λ stub antennas:

https://drive.google.com/file/d/0B1XizxEfB23tUHJOeFpTZkRUc1k/view
https://drive.google.com/file/d/0B1XizxEfB23tWDBTTXpWMkVLOTA/view
https://drive.google.com/file/d/0B1XizxEfB23tQThhUmkzck9xZGM/view
https://drive.google.com/file/d/0B1XizxEfB23tdXZHUTMyekx4eWs/view
https://drive.google.com/file/d/0B1XizxEfB23tWVJLNmI4NzNPQlE/view

So maybe it is the location of the antennas that is not correct. Shouldn't they be located more near the center of axi-symmetry of the cavity, like in the picture below?
Shells idea isnt bad but some parts of the magnetic vector fields around the dipoles are not equal to the field of the TE01 mode. Caused by that the excited field will be degenerated/ deformed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 12:42 PM
NSF-1701 Flight Test 2A laser position graph posted on Reddit (https://www.reddit.com/r/EmDrive/comments/3iy440/nsf1701_flight_test_2a_laser_position_graph/) by @EmDriven.

@kwertyops: did you flip your graphs upside-down in order to show a downwards thrust of the frustum going with the curve going also downwards? I'm talking of your graphs in this post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421125#msg1421125).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 12:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421121#msg1421121">Quote from: aero on 08/30/2015 04:34 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421114#msg1421114">Quote from: deltaMass on 08/30/2015 03:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421104#msg1421104">Quote from: aero on 08/30/2015 02:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421098#msg1421098">Quote from: deltaMass on 08/30/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421093#msg1421093">Quote from: aero on 08/30/2015 01:27 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.
I'm talking about the software that calculates ridiculously high Q values.
And either dial down the aggression, or get some fresh air and walk it off.
Too many gangster movies?
Reading Tom Clancy's "Support and Defend." But I find pot shots in the dark annoying in the best of times.

As for the meat of your comment, the calculated Q values are not very useful as numeric values. I have found though that ridiculously high Q values result in calculated field evolution that clearly leads to resonance while very low to no Q values result in calculated fields that really never evolve to anything discernible. As far as I can tell that is the utility of the calculated Q from this program.

Perhaps you can tell me this - Can these cavity field patterns be considered as Bloch Periodic? I ask because I have MPB installed but have never used it. It is applicable to problems that satisfy Bloch's Theorem.

MPB, also developed at MIT, can be thought of as a sister program to meep, it calculates frequencies and modes using Fourier transforms. I speculate that many meep users avoid Harminv and use MPB instead but have no basis to say that.
I just finished watching Salt. I regret that you were annoyed. Obviously you identify pretty closely with the code. At least you've shown that the Q value spat out is of qualitative use, even though the absolute value is useless. That's worth knowing.

Many years ago I did a degree which included solid state physics and I recall Bloch. But since I haven't used it since, I've forgotten about it. I'm not your man for that.

Here is the Harminv definition: Does it make sense to you?

Quote
(harminv-Q result)
    Return dimensionless lifetime, or "quality factor", Q, defined as -\mathrm{Re}\,\omega / 2 \mathrm{Im}\,\omega.
(that is, -Re(w) / 2 Im(w), the negative of the real part of the complex frequency divided by twice the imaginary part)

As I understand things, the frequency should be real so the imaginary part should be tiny and so Q should be huge?

1) The equation in Meep to calculate Q is correct.  However, any equation is subject to the principle of "GIGO" ( http://www.thefreedictionary.com/GIGO ).  No correct equation can give a correct solution when incorrect material constants are used.

2) The Q you calculate is too large because the Drude constant values used are equivalent to having too small power losses.  In other words, the Drude constant values you use are an incorrect model of physical reality.  Are you using the Drude constants suggested by deltaMass ??? We had discussed in the past changing the Drude constants and conducting Meep runs to see the change in Q with Drude constant values. 

3) Take a look at http://sourceforge.net/p/b-calm/discussion/1746892/thread/913537ab/, where a user tells another user that eps averaging in Meep was responsible for Meep giving Q values orders of magnitude larger than the Q calculated by Belgium California Light Machine (B-CALM, a 3D GPU-based Finite-Difference Time-Domain program for electromagnetic problems):

Quote
With MEEP this particular ring resonator has Q ~ 10^7 however with BCALM I am not able to reach 10^5.

That's a factor of more than 100 difference, equivalent to the factor difference between a Q of 5 million and a Q of 50,000. 

  The Meep user finally admitted that by turning eps averaging off the Q value calculated by Meep came down to only 3 times the Q value calculated by B-CALM.

However, this does not necessarily mean that the results with eps averaging turned off are better, all it means is that there are more losses with eps averaging turned off.  The correct way to simulate power losses is with the correct values of the Drude model, which should be changed until you get a reasonable Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 08/30/2015 12:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421125#msg1421125">Quote from: kwertyops on 08/30/2015 04:51 AM</a>
Okay, here's the TrackMate analysis on NSF-1701 #2A.

My interpretation is that this confirms that your knife-edge balance is sticking (see the lack of recovery from when the weight was added, to after it was taken off.

I've included two images:

-One with the full data plot - this would be the one to look at for thrust signatures during the run. To my eye there appears to be either none, or else possibly a downward thrust at the very beginning of the run (it is hard to tell due to lengthy laser obstruction immediately prior to the run)

-Another where I've shrunk the x-axis from the time when the microwave is started until the end - this one makes it easier to see what we're identifying as the thermal lift, and the subsequent recovery. It does appear to go back down after the run is completed, even below its original height

My take on this run as a whole is that it seems to indicate that the knife-edge fulcrum might be a problem, especially in long-term height drift measurement.

However, that doesn't necessarily imply that it's not still useful for short-term thrust measurement.

[Edit] I'm now also attaching the raw data that goes with that plot (whitespace separated values).

can you upload the full trackmate data file plese, this just has displacement.

Also

Can you upload the video that's generated?  I suspect that the change in the target made spotify splot.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 01:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421119#msg1421119">Quote from: Silversheep2011 on 08/30/2015 04:20 AM</a>
rfmwguy
You are best person to ask,  look from about 15:00 -15:50

there is what appears to be a blue light in background moving up and down a bit
doesn't seem that noticeable elsewhere.
What is it do you think it is?
Where is it coming from?

and thankyou for posting -it's quite fun...
The blue in the vid is a reflection of the android screen on the laser paper. There is probably something on the screen moving about as its recording. I'll try to fix that next time...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 01:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421138#msg1421138">Quote from: deltaMass on 08/30/2015 07:02 AM</a>
Does this confirm that the pivot is sticky? - it looks that way.

@aero: The harminv thing makes no sense to me.
I think there is abit, DM. Will take me a while to look at the data, but it does seem its not recentering. Still useful for testing for magnetron thrust, but not an ideal balance. Off to a company golf outing...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/30/2015 01:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421173#msg1421173">Quote from: Rodal on 08/30/2015 12:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421121#msg1421121">Quote from: aero on 08/30/2015 04:34 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421114#msg1421114">Quote from: deltaMass on 08/30/2015 03:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421104#msg1421104">Quote from: aero on 08/30/2015 02:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421098#msg1421098">Quote from: deltaMass on 08/30/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421093#msg1421093">Quote from: aero on 08/30/2015 01:27 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421087#msg1421087">Quote from: deltaMass on 08/30/2015 01:02 AM</a>
There's something very, very wrong there, as should be obvious.
You talking to me? If so, spill it, maybe we agree.
I'm talking about the software that calculates ridiculously high Q values.
And either dial down the aggression, or get some fresh air and walk it off.
Too many gangster movies?
Reading Tom Clancy's "Support and Defend." But I find pot shots in the dark annoying in the best of times.

As for the meat of your comment, the calculated Q values are not very useful as numeric values. I have found though that ridiculously high Q values result in calculated field evolution that clearly leads to resonance while very low to no Q values result in calculated fields that really never evolve to anything discernible. As far as I can tell that is the utility of the calculated Q from this program.

Perhaps you can tell me this - Can these cavity field patterns be considered as Bloch Periodic? I ask because I have MPB installed but have never used it. It is applicable to problems that satisfy Bloch's Theorem.

MPB, also developed at MIT, can be thought of as a sister program to meep, it calculates frequencies and modes using Fourier transforms. I speculate that many meep users avoid Harminv and use MPB instead but have no basis to say that.
I just finished watching Salt. I regret that you were annoyed. Obviously you identify pretty closely with the code. At least you've shown that the Q value spat out is of qualitative use, even though the absolute value is useless. That's worth knowing.

Many years ago I did a degree which included solid state physics and I recall Bloch. But since I haven't used it since, I've forgotten about it. I'm not your man for that.

Here is the Harminv definition: Does it make sense to you?

Quote
(harminv-Q result)
    Return dimensionless lifetime, or "quality factor", Q, defined as -\mathrm{Re}\,\omega / 2 \mathrm{Im}\,\omega.
(that is, -Re(w) / 2 Im(w), the negative of the real part of the complex frequency divided by twice the imaginary part)

As I understand things, the frequency should be real so the imaginary part should be tiny and so Q should be huge?

1) The equation in Meep to calculate Q is correct.  However, any equation is subject to the principle of "GIGO"= Garbage In = Garbage Out.  No correct equation can give a correct solution when incorrect material constants are used.

2) The Q you calculate is too large because the Drude constant values used are equivalent to having too small power losses.  In other words, the Drude constant values you use are an incorrect model of physical reality.  Are you using the Drude constants suggested by deltaMass ??? We had discussed in the past changing the Drude constants and conducting Meep runs to see the change in Q with Drude constant values. 

3) Take a look at http://sourceforge.net/p/b-calm/discussion/1746892/thread/913537ab/, where a user tells another user that eps averaging in Meep was responsible for Meep giving Q values orders of magnitude larger than the Q calculated by Belgium California Light Machine (B-CALM, a 3D GPU-based Finite-Difference Time-Domain program for electromagnetic problems):

Quote
With MEEP this particular ring resonator has Q ~ 10^7 however with BCALM I am not able to reach 10^5.


  The Meep user finally admitted that by turning eps averaging off the Q value calculated by Meep came down to only 3 times the Q value calculated by B-CALM.

Major changes have happened over the last week. I've pretty much rebuilt most of my test bed. Having to relayout the center sections holding the fulcrum and electronics plus the faraday cage is bigger, as it was very hard for me to get into the old one, just a little too small. Should have figured that out when I laid it out.

It all boiled down to me not being a cement gal. In my first antivibration beds (Tubs I had got from Home Depot the bottoms were too thin and allowed flexing when I mounted the test platforms on it. I thought I had a great solution in using some of the basic design with the foam inserts that I'd glued into the bottom but I'd cover it with cement to add stiffness and weight and still dampen vibration with the foam. I mixed the cement. weighed it and poured it in the tub over the foam. When it set it looked ok. But I set the 75 pound supports for the fulcrum on it, it cracked. I had no idea what I did wrong. Got an pm telling me that cement that was too dry would crack. Then the light came on. Foam sucking up water from the cement making it drier and then cracked.  It made me layout the dang thing again because everything was too short. Just stupid...

Also the issues with sticking on the knife edges like with mwrfguy's concerned me. Mine wasn't as pronounced but When I'd add simulated weights to the ends of the fulcrum arms without any dampening it would oscillate up to 5 minutes before I could even see it slowing down. I didn't like that up and down. I think I've figured out a way and I'll try it today by using a page from the old balance beam maintenance book. Thanks frobnicat for the great link. I found a great way to dampen the oscillations and still keep the accuracy. I did have the oil dampener on one end of the fulcrum but now I'm going to drop a rod from the center of it down to a small weight into the oil damper, that way I'll dampen both ends  equally and stabilize the fulcrum.

Also I'm going to be using a hardened piece of angle iron with two dulled and rounded knife edges. The angle iron is from a old bed frame. I couldn't cut it with a hack saw and had to use a 12" cutoff saw with a carbide blade to even cut it, tough stuff.

Today I'm going to work on the fulcrum arm and finish cleaning up the redesigned disaster I made in the shop.

On the other side with the meep analysis of the frustum I've come to the conclusion that without modeling the loop or square antenna any layouts will be lacking on exciting the TE mode. I don't worry about the huge Q's and figured that was an artifact of meep but the mode shapes are important.

Last and best. I'll be posting pictures tonight of where I am, because inquiring minds want to know. I have some friends dropping in today and they are going to help. One is an former employee of mine and one heck of a electronics tech and Ham, love working with him. It will be nice to have some help.

Shell
speelings

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 02:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421184#msg1421184">Quote from: SeeShells on 08/30/2015 01:53 PM</a>
...On the other side with the meep analysis of the frustum I've come to the conclusion that without modeling the loop or square antenna any layouts will be lacking on exciting the TE mode....
I agree,  I've come to the same conclusion that without modeling the loop antenna you will not be properly exciting an axi-symmetric TE mode. (See emphasis on "axi-symmetric")

Still, this shows that Meep has been very useful in showing how important is the antenna's shape and its location  Even when Meep excited a TE mode with a parallel dipole (for the Yang/Shell 6 degree cone angle geometry) , the mode shapes were not axi-symmetric.  The only way that appears possible to excite an axi-symmetric TE mode is with a loop antenna.  A square antenna will not do, I think, because the square shape is incompatible with circumferential axi-symmetry. 

Even when Meep excites a TM mode with a dipole, the mode shape is not axi-symmetric either.  The antenna really distorts the mode shape into two perpendicular axes: parallel to the dipole and perpendicular to the dipole.

The other thing we have learned from Meep (post processed with Wolfram Mathematica) is that the EM Drive cannot be modeled solely with standing waves (as done for example by Greg Egan, as an eigenvalue problem, ignoring the effect of the RF feed).  It is crucial to model the RF feed: it changes the conditions inside the cavity, particularly the stresses at the big base

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 02:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421130#msg1421130">Quote from: kwertyops on 08/30/2015 06:26 AM</a>
One more, with areas of interest for this flight.
Kwertyops, very impressed with your work...thank you. Stickiness is there making it an imperfect balance but useable for short term changes as you said. I can also reset balance points to unused portions of blades which I did not do in ft2a. I'm afraid the oscillations at start of run are my keypad inputs on microwave. It is electromechanicly connected to nsf-1701 through galinstan, but this is high viscosity and think it transmits small vibrations like a solid coupling. I've got to remote the power on signal and will try and do that over the next several days.  Small improvements bit by bit thanks to your analysis.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/30/2015 02:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421186#msg1421186">Quote from: Rodal on 08/30/2015 02:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421184#msg1421184">Quote from: SeeShells on 08/30/2015 01:53 PM</a>
...On the other side with the meep analysis of the frustum I've come to the conclusion that without modeling the loop or square antenna any layouts will be lacking on exciting the TE mode....
I agree,  I've come to the same conclusion that without modeling the loop antenna you will not be properly exciting an axi-symmetric TE mode. (See emphasis on "axi-symmetric")

Still, this shows that Meep has been very useful in showing how important is the antenna's shape and its location  Even when Meep excited a TE mode with a parallel dipole (for the Yang/Shell 6 degree cone angle geometry) , the mode shapes were not axi-symmetric.  The only way that appears possible to excite an axi-symmetric TE mode is with a loop antenna.  A square antenna will not do, I think, because the square shape is incompatible with circumferential axi-symmetry. 

Even when Meep excites a TM mode with a dipole, the mode shape is not axi-symmetric either.  The antenna really distorts the mode shape into two perpendicular axes: parallel to the dipole and perpendicular to the dipole.

The other thing we have learnt from Meep(post processed with Wolfram Mathematica) is that the EM Drive cannot be modeled solely with standing waves (as done for example by Greg Egan, as an eigenvalue problem, ignoring the effect of the RF feed).  It is crucial to model the RF feed: it changes the conditions inside the cavity, particularly the stresses at the big base

Absolutely!

I couldn't agree more. This is also the case with injecting the magnetron directly into the cavity whether it's with a Z-matched hole in the top or bottom or sidewall injection, axisymmetrically injections is the key for the correct mode generation. Only then the cones asymmetrical shape will lead to the highest stress generation on the plates and walls.
I believe some at EW understood this just from looking at some of the layouts and I wish they could comment but sadly they can not.

Loop or square. I was thinking if areo could model a very short cylinder why couldn't he model one inside the frustum with a small section cut away where the feeds are? I'm probably over simplifying it and it is a tough nut to crack.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/30/2015 03:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421191#msg1421191">Quote from: SeeShells on 08/30/2015 02:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421186#msg1421186">Quote from: Rodal on 08/30/2015 02:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421184#msg1421184">Quote from: SeeShells on 08/30/2015 01:53 PM</a>
...On the other side with the meep analysis of the frustum I've come to the conclusion that without modeling the loop or square antenna any layouts will be lacking on exciting the TE mode....
I agree,  I've come to the same conclusion that without modeling the loop antenna you will not be properly exciting an axi-symmetric TE mode. (See emphasis on "axi-symmetric")

Still, this shows that Meep has been very useful in showing how important is the antenna's shape and its location  Even when Meep excited a TE mode with a parallel dipole (for the Yang/Shell 6 degree cone angle geometry) , the mode shapes were not axi-symmetric.  The only way that appears possible to excite an axi-symmetric TE mode is with a loop antenna.  A square antenna will not do, I think, because the square shape is incompatible with circumferential axi-symmetry. 

Even when Meep excites a TM mode with a dipole, the mode shape is not axi-symmetric either.  The antenna really distorts the mode shape into two perpendicular axes: parallel to the dipole and perpendicular to the dipole.

The other thing we have learnt from Meep(post processed with Wolfram Mathematica) is that the EM Drive cannot be modeled solely with standing waves (as done for example by Greg Egan, as an eigenvalue problem, ignoring the effect of the RF feed).  It is crucial to model the RF feed: it changes the conditions inside the cavity, particularly the stresses at the big base

Absolutely!

I couldn't agree more. This is also the case with injecting the magnetron directly into the cavity whether it's with a Z-matched hole in the top or bottom or sidewall injection, axisymmetrically injections is the key for the correct mode generation. Only then the cones asymmetrical shape will lead to the highest stress generation on the plates and walls.
I believe some at EW understood this just from looking at some of the layouts and I wish they could comment but sadly they can not.

Loop or square. I was thinking if areo could model a very short cylinder why couldn't he model one inside the frustum with a small section cut away where the feeds are? I'm probably over simplifying it and it is a tough nut to crack.

Shell
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 04:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/30/2015 04:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no long dipole antennas: long antennas distort the symmetry of the modes !
From what I've heard and been PMed by an old friend (retired high energy physics). You can generate a stable mode in a frustum, not easy, but doable and this is what I'm looking for!

Got my coffee and back to the shop!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 04:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no long dipole antennas: long antennas distort the symmetry of the modes !

I can probably do something like that but I sure wish there were another meeper who would make and run some models of their own. Someone working the same problem to compare notes with.

As for artificially changing the Drude model so that the calculated Q value is realistic, I don't know. Could probably do it but I believe it would need to be done on a case by case basis. I don't think I would find a "One size fits all" solution. And I am reluctant to add the series of runs required for realistic Q to every change in the model. As all can see, calculated Q changes by changing the antenna and it also changes for the same cavity, same antenna but different EM field component excitation. The current model, CE2 - 8 gives a Q ranging from nothing to 47 million depending on which of the six field components is used to excite the antennas. I'm pretty sure that adding resistance to the copper without a sound theoretical basis would be a lost cause. The current model does have a sound theoretical basis at least. There may be something missing (no idea what) but what is there is soundly based.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 04:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421209#msg1421209">Quote from: aero on 08/30/2015 04:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no long dipole antennas: long antennas distort the symmetry of the modes !

I can probably do something like that but I sure wish there were another meeper who would make and run some models of their own. Someone working the same problem to compare notes with.

As for artificially changing the Drude model so that the calculated Q value is realistic, I don't know. Could probably do it but I believe it would need to be done on a case by case basis. I don't think I would find a "One size fits all" solution. And I am reluctant to add the series of runs required for realistic Q to every change in the model. As all can see, calculated Q changes by changing the antenna and it also changes for the same cavity, same antenna but different EM field component excitation. The current model, CE2 - 8 gives a Q ranging from nothing to 47 million depending on which of the six field components is used to excite the antennas. I'm pretty sure that adding resistance to the copper without a sound theoretical basis would be a lost cause. The current model does have a sound theoretical basis at least. There may be something missing (no idea what) but what is there is soundly based.

I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies

Q's of millions are completely unrealistic, and show that the Meep models are not realistically incorporating power losses.  I don't see that as being "soundly based".

Not addressing the Drude constants in the model just ensures that the Q will continue to be unrealistic in future runs.

We may all choose not to do certain things, for example because we have better things to do, for example I could write my own Finite Difference code to analyze this problem, but I chose not to do so, because I have better things to do.  But that doesn't mean that we cannot discuss and agree on what are the right things to do if anybody would chose to do so.  Using these Drude material constants are not a good model of reality.
________

PS: Did you address the fact that the user said that turning off eps averaging decreases the Q by a factor of 100 ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/30/2015 05:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421209#msg1421209">Quote from: aero on 08/30/2015 04:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no long dipole antennas: long antennas distort the symmetry of the modes !

I can probably do something like that but I sure wish there were another meeper who would make and run some models of their own. Someone working the same problem to compare notes with.

As for artificially changing the Drude model so that the calculated Q value is realistic, I don't know. Could probably do it but I believe it would need to be done on a case by case basis. I don't think I would find a "One size fits all" solution. And I am reluctant to add the series of runs required for realistic Q to every change in the model. As all can see, calculated Q changes by changing the antenna and it also changes for the same cavity, same antenna but different EM field component excitation. The current model, CE2 - 8 gives a Q ranging from nothing to 47 million depending on which of the six field components is used to excite the antennas. I'm pretty sure that adding resistance to the copper without a sound theoretical basis would be a lost cause. The current model does have a sound theoretical basis at least. There may be something missing (no idea what) but what is there is soundly based.

In for another cuppa coffee.

Question, how does the meep software calculate the Q? it it a one simulated pulse into the cavity or does it look at a set series. The reason is if we are collapsing a mode every full wavelength and regaining it in the next. How can you get any Q from the decaying modes so frequently? Can it be specified the number of pulses meep uses in calculating the Q?

Back out.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 05:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421212#msg1421212">Quote from: SeeShells on 08/30/2015 05:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421209#msg1421209">Quote from: aero on 08/30/2015 04:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no long dipole antennas: long antennas distort the symmetry of the modes !

I can probably do something like that but I sure wish there were another meeper who would make and run some models of their own. Someone working the same problem to compare notes with.

As for artificially changing the Drude model so that the calculated Q value is realistic, I don't know. Could probably do it but I believe it would need to be done on a case by case basis. I don't think I would find a "One size fits all" solution. And I am reluctant to add the series of runs required for realistic Q to every change in the model. As all can see, calculated Q changes by changing the antenna and it also changes for the same cavity, same antenna but different EM field component excitation. The current model, CE2 - 8 gives a Q ranging from nothing to 47 million depending on which of the six field components is used to excite the antennas. I'm pretty sure that adding resistance to the copper without a sound theoretical basis would be a lost cause. The current model does have a sound theoretical basis at least. There may be something missing (no idea what) but what is there is soundly based.

In for another cuppa coffee.

Question, how does the meep software calculate the Q? it it a one simulated pulse into the cavity or does it look at a set series. The reason is if we are collapsing a mode every full wavelength and regaining it in the next. How can you get any Q from the decaying modes so frequently? Can it be specified the number of pulses meep uses in calculating the Q?

Back out.

Shell

It is calculated by Harmonic Inversion (see http://ab-initio.mit.edu/wiki/index.php/Harminv ), as the 1/2 ratio of the real and imaginary parts of the frequencies calculated by Harmonic Inversion.

It is not analyzing a pulse or a set series of pulses but finitely-many sinusoids of varying magnitude and varying frequency.

Quote
given a discrete-time, finite-length signal that consists of a sum of finitely-many sinusoids (possibly exponentially decaying) in a given bandwidth, it determines the frequencies, decay constants, amplitudes, and phases of those sinusoids.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 05:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421212#msg1421212">Quote from: SeeShells on 08/30/2015 05:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421209#msg1421209">Quote from: aero on 08/30/2015 04:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no long dipole antennas: long antennas distort the symmetry of the modes !

I can probably do something like that but I sure wish there were another meeper who would make and run some models of their own. Someone working the same problem to compare notes with.

As for artificially changing the Drude model so that the calculated Q value is realistic, I don't know. Could probably do it but I believe it would need to be done on a case by case basis. I don't think I would find a "One size fits all" solution. And I am reluctant to add the series of runs required for realistic Q to every change in the model. As all can see, calculated Q changes by changing the antenna and it also changes for the same cavity, same antenna but different EM field component excitation. The current model, CE2 - 8 gives a Q ranging from nothing to 47 million depending on which of the six field components is used to excite the antennas. I'm pretty sure that adding resistance to the copper without a sound theoretical basis would be a lost cause. The current model does have a sound theoretical basis at least. There may be something missing (no idea what) but what is there is soundly based.

In for another cuppa coffee.

Question, how does the meep software calculate the Q? it it a one simulated pulse into the cavity or does it look at a set series. The reason is if we are collapsing a mode every full wavelength and regaining it in the next. How can you get any Q from the decaying modes so frequently? Can it be specified the number of pulses meep uses in calculating the Q?

Back out.

Shell

Meep runs the model for a period of time using a Gaussian noise source, the source is turned off and the fields are propagated for a user specified time. At the end of that time the un-decayed fields are fitted (by Harminv) to a number of exponentially decaying sin waves(?) and those fits that exceed Q=50 are output as the frequency and quality factor. Q is calculated as - Re(w) / 2 Im(w) - real over twice the imaginary part of the fitted frequency.

Default is to search for 5 frequencies but can search for up to 100 frequencies. For the EM drive cavities it is rare for Harminv to return more than 1, sometimes 2 frequencies unless the noise bandwidth is set very wide.

Note: Sorry Dr. Rodal, we cross posted the same answer

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 05:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421200#msg1421200">Quote from: Rodal on 08/30/2015 03:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421188#msg1421188">Quote from: rfmwguy on 08/30/2015 02:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421130#msg1421130">Quote from: kwertyops on 08/30/2015 06:26 AM</a>
One more, with areas of interest for this flight.
Kwertyops, very impressed with your work...thank you. Stickiness is there making it an imperfect balance but useable for short term changes as you said. I can also reset balance points to unused portions of blades which I did not do in ft2a. I'm afraid the oscillations at start of run are my keypad inputs on microwave. It is electromechanicly connected to nsf-1701 through galinstan, but this is high viscosity and think it transmits small vibrations like a solid coupling. I've got to remote the power on signal and will try and do that over the next several days.  Small improvements bit by bit thanks to your analysis.

Is the green portion of the test results showing the truncated cone moving in the direction of the small base (when the magnetron is on) much larger and significant than in previous test runs? 
(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1062044,3Bimage.pagespeed.ic.Eb_5Iaovfl.jpg)

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1062673,3Bimage.pagespeed.ic.NDiZfQivy0.jpg)

This is the first run for NSF-1701 where I see a very clear movement in the direction of the small base

If so, can you point out to what changes in this latest run may have been responsible (in your view) for the very noticeable movement toward the small base?


Rodal, as I said the two graphs are identical but one of them has been flipped upside-down, see the drawing below where I put them together on the same scale.

The small base in NSF-1701 Flight Test 2A points towards the floor, downwards. When the frustum goes upwards (a priori due to thermal effects) the laser dot goes downwards.

EmDriven (blue/brown curve) on Reddit claims he showed the weight, whereas kwertyops (red) shows laser position (?)

kwertyops's curve increases while EmDriven's brown portion of his blue curve decreases. There is something I don't understand in those curves: to me it a appears a weight reduction (EmDriven) should follow laser position (kwertyops) in the same trend, because both would track a frustum going upwards. But they are opposite. Why?

For now in my opinion there is no thrust signature in NSF-1701 Flight Test 2A graphs, only vibration and thermal artifacts.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 05:24 PM

Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/30/2015 05:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !
I have a suggestion for the model.

Cone dimensions (CrazyEddie).
Dipole orientation like in the picture(YangShell), but more and shorter antennas around the circumference near the big end.


Note that the YangShell design with only two dipoles in this configuration showed TE01 but deformed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 05:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421221#msg1421221">Quote from: aero on 08/30/2015 05:24 PM</a>
Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.
An important issue is that Harminv (the harmonic inversion software for Meep) is being used to examine the response so far when the response is growing exponentially during the transient with the RF Feed on.

The correct way to calculate Q (as we discussed before) should be:

1) Run Meep with an RF feed ON, for a geometry and RF feed where the Meep model excites the same mode that is excited at the natural frequency in an eigenvalue problem (with standing waves, no RF feed).

2) Turn the RF feed OFF in Meep after a reasonably amount of time has elapsed (from prior calculations, it looks like 128 cycles would be OK, as by that time the amplitude is close to being stable, as the exponential growth has decreased significantly)

3) Use Harminv to harmonically invert the frequency response with the RF feed OFF, and determine the Q for the RF feed off.

The present analysis for Q are being done with the RF feed on, and therefore do not represent a clean decay of the response, since with the RF feed ON one has an exponentially growing response instead of a decaying response.

In general, damping, and hence Q, is simpler to analyze with the source of oscillation being OFF. 

This is crucial for a problem, like this one, where there is no closed-form solution for the RF feed ON

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 05:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421226#msg1421226">Quote from: X_RaY on 08/30/2015 05:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !
I have a suggestion for the model.

Cone dimensions (CrazyEddie).
Dipole orientation like in the picture(YangShell), but more and shorter antennas around the circumference near the big end.


Note that the YangShell design with only two dipoles in this configuration showed TE01 but deformed.

That is a clear description of the general idea. Now could you give the engineering specification of what you'd like to see? Once SeeShells vets it, I can try to build it. No guarantees but I can guarantee nothing without real, clear specifications.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 08/30/2015 06:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421171#msg1421171">Quote from: flux_capacitor on 08/30/2015 12:42 PM</a>
NSF-1701 Flight Test 2A laser position graph posted on Reddit (https://www.reddit.com/r/EmDrive/comments/3iy440/nsf1701_flight_test_2a_laser_position_graph/) by @EmDriven.

@kwertyops: did you flip your graphs upside-down in order to show a downwards thrust of the frustum going with the curve going also downwards? I'm talking of your graphs in this post (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421125#msg1421125).

I actually didn't flip it myself, that's how the data came out of TrackMate. I expect that it's using the pixel coordinate system where the positive y-direction is downwards (laser goes down, y increases, graph goes upwards).

So in your image with the blue and red plot, the red one (mine) is actually reflective of the frustum position, while the blue one (EmDriven) is showing the laser position. But yes, they should be mostly mirror images of each other.

[Edit] So, just to be clear - we are both showing laser position, but mine (red) is flipped to the pixel coordinate system, and so it more directly reflects the frustum position. When the red line moves down, that is the frustum moving down. The blue graph reflects just the laser position, as you see it visually in the video, in a normal cartesian coordinate system. When the blue line goes down, the frustum is going up.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421174#msg1421174">Quote from: glennfish on 08/30/2015 12:55 PM</a>
can you upload the full trackmate data file plese, this just has displacement.

Also

Can you upload the video that's generated?  I suspect that the change in the target made spotify splot.

The video output seems like it's taking prohibitively long, so I'm not going to try to do that, but I will include the cropped input video, and the full raw TrackMate data (XML). Please note that for this run I applied a slight Gaussian Blur to the video beforehand, to minimize the effect of that blue reflection, as well as due to the grid markers potentially causing aberrations.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421219#msg1421219">Quote from: flux_capacitor on 08/30/2015 05:21 PM</a>
...Rodal, as I said the two graphs are identical but one of them has been flipped upside-down, see the drawing below where I put them together on the same scale.

The small base in NSF-1701 Flight Test 2A points towards the floor, downwards. When the frustum goes upwards (a priori due to thermal effects) the laser dot goes downwards.

EmDriven (blue/brown curve) on Reddit claims he showed the weight, whereas kwertyops (red) shows laser position (?)

kwertyops's curve increases while EmDriven's brown portion of his blue curve decreases. There is something I don't understand in those curves: to me it a appears a weight reduction (EmDriven) should follow laser position (kwertyops) in the same trend, because both would track a frustum going upwards. But they are opposite. Why?

For now in my opinion there is no thrust signature in NSF-1701 Flight Test 2A graphs, only vibration and thermal artifacts.
Thank you so much for kindly taking the time to explain this so clearly and thoroughly.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 08/30/2015 06:17 PM
Does somebody know if a tentative has been made to analyse the RF cavity thruster phenomena at the light of the analysis by James Woodward of the Mach principle in the frame of General Relativity of Einstein ?
The thesis of Woodward is that the  Mach Principle on the origin of Inertia forces is a logical consequence of both General Relativity and the fact that our space-time is flat (confirmed by WMAP and Planck Space experiments on the microwave radiation background). This thesis is presented in the book of Woodward "Making Starships and Stargates - The Science of Interstellar Transport and Absurdly Benign Wormholes" edited by Springer.

James Woodward explains that an object which is accelerated by a force while it accumulates energy will experience mass fluctuations which can be utilized to provide thrust on the object itself, without need of local momentum conservation (the momentum is conserved at the the whole universe level).

I have read this book this week (somewhat in diagonal as the mathematical part is not so benign to assimilate !). It is evident that our RF cavity  is submited to the acceleration of the Earth gravitation, that it stores internal energy via a high frequency electromagnetic process. So following Woodward/Mach this cavity should present mass fluctuations. Now it should be sufficient to search and identified a force applied in quadrature with this mass fluctuations to be sure (according Woodward) that a "magic" thrust will appear on the RF cavity.

Could a phenomena of electrostriction play the role of this quadrature force ??  ::)

In any case the book of Woodward is worth to be read  !!!  :D
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/30/2015 06:17 PM
Didn't TheTraveller estimate, with the projected Q of NSF-1701 that we would see a force of around 140 micronewton's (approx 14mg)?  The upward force of thermal effects is going to swamp any downward thrust source.  Run 2 had an interesting result where the system stabilizes on power off, then rmfwguy walks by it, causing it to move lower (drive up) as if inertia had been holding the beam laser at a higher position (device lower) than the direction the rising hot air wants to go. 

Given the stickiness of the beam, I'm not sure if this is not simply an artifact of the rig.  Without something to break the inertia of the rig, I would expect the slow decay of any downwward energy (device up) would be swamped by thermal cooling (device down). 

My advice, walk by the thing on power off and see what happens.  Also consider a build that feeds by coax in order to increase Q and separate a major heat source from the device.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/30/2015 06:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421221#msg1421221">Quote from: aero on 08/30/2015 05:24 PM</a>
Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.
Sad to say I threw away the papers containing that work.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/30/2015 06:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421229#msg1421229">Quote from: Rodal on 08/30/2015 05:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421221#msg1421221">Quote from: aero on 08/30/2015 05:24 PM</a>
Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.
An important issue is that Harminv (the harmonic inversion software for Meep) is being used to examine the response so far when the response is growing exponentially during the transient with the RF Feed on.

The correct way to calculate Q (as we discussed before) should be:

1) Run Meep with an RF feed ON, for a geometry and RF feed where the Meep model excites the same mode that is excited at the natural frequency in an eigenvalue problem (with standing waves, no RF feed).

2) Turn the RF feed OFF in Meep after a reasonably amount of time has elapsed (from prior calculations, it looks like 128 cycles would be OK, as by that time the amplitude is close to being stable, as the exponential growth has decreased significantly)
Meep turns the RF feed off based on its internal calculations, not user specified.
Quote
3) Use Harminv to harmonically invert the frequency response with the RF feed OFF, and determine the Q for the RF feed off.
That is exactly what is done -

    (run-sources+ (* gc T_meep)  ; This time, # peroids, is for non-resonant frequencies dissapation.
    ; Lower Q, shorter time, higher Q, longer time before measurement made. Take your best guess.
        (after-sources (harminv Ez (vector3 0.05 0.05 0.05) fmeep BW 5)) )
Quote
The present analysis for Q are being done with the RF feed on, and therefore do not represent a clean decay of the response, since with the RF feed ON one has an exponentially growing response instead of a decaying response.
No, that is not correct. Harminv does not start until a user specified time (* gc T_meep) after sources are turned off.

We are probably overlooking the elephant in the room. That is resolution. The resistance of the copper cavity only effects the model within the skin depth of the copper, a few micrometers. The grid spacing is on the order of millimetres (1.2 mm) so meep has no way to detect an effect from that resistance. 

At resolution of 250 the number of computational cells is 12,323,175 for the CE2 model At about 10 words of data storage per data cell gives - call it 125 MB of memory required. Double the resolution to 500 gives grid spacing of about 0.6 mm and requires about 1 GB of computer memory. Double it again and at 8 GB the problem is well beyond my machine but the grid spacing is only down to 300 micrometers.

Increasing resolution with a realistic copper model is not the solution so we need a copper model that simulates the real effect at much lower resolution. I model cone wall and end thickness as 1/4 inch,  6.35 mm or 5 + computational cells thick but the simulated RF reflects off the surface (IMO). I need a copper model that reflects 2.5  GHz RF with a skin depth of 6 mm and resistance equal to copper at that frequency. But I have no idea where to start.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 06:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421236#msg1421236">Quote from: Rodal on 08/30/2015 06:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421219#msg1421219">Quote from: flux_capacitor on 08/30/2015 05:21 PM</a>
...Rodal, as I said the two graphs are identical but one of them has been flipped upside-down, see the drawing below where I put them together on the same scale.

The small base in NSF-1701 Flight Test 2A points towards the floor, downwards. When the frustum goes upwards (a priori due to thermal effects) the laser dot goes downwards.

EmDriven (blue/brown curve) on Reddit claims he showed the weight, whereas kwertyops (red) shows laser position (?)

kwertyops's curve increases while EmDriven's brown portion of his blue curve decreases. There is something I don't understand in those curves: to me it a appears a weight reduction (EmDriven) should follow laser position (kwertyops) in the same trend, because both would track a frustum going upwards. But they are opposite. Why?

For now in my opinion there is no thrust signature in NSF-1701 Flight Test 2A graphs, only vibration and thermal artifacts.
Thank you so much for kindly taking the time to explain this so clearly and thoroughly.

First and foremost thanks to kwertyops for his explanation! Everything is clear now. But for a moment I through we were seing a thrust downwards, which alas didn't occur. Let's continue the investigation!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 06:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421244#msg1421244">Quote from: aero on 08/30/2015 06:29 PM</a>
..
No, that is not correct. Harminv does not start until a user specified time (* gc T_meep) after sources are turned off.

We are probably overlooking the elephant in the room. That is resolution. The resistance of the copper cavity only effects the model within the skin depth of the copper, a few micrometers. The grid spacing is on the order of millimetres (1.2 mm) so meep has no way to detect an effect from that resistance. 

At resolution of 250 the number of computational cells is 12,323,175 for the CE2 model At about 10 words of data storage per data cell gives - call it 125 MB of memory required. Double the resolution to 500 gives grid spacing of about 0.6 mm and requires about 1 GB of computer memory. Double it again and at 8 GB the problem is well beyond my machine but the grid spacing is only down to 300 micrometers.

Increasing resolution with a realistic copper model is not the solution so we need a copper model that simulates the real effect at much lower resolution. I model cone wall and end thickness as 1/4 inch,  6.35 mm or 5 + computational cells thick but the simulated RF reflects off the surface (IMO). I need a copper model that reflects 2.5  GHz RF with a skin depth of 6 mm and resistance equal to copper at that frequency. But I have no idea where to start.

Thanks for explaining that Harminv starts by turning the sources off.  That makes lots of sense to me.  It didn't make sense to calculate the Q with the sources on.

It doesn't make numerical sense to model the skin depth with a finite difference scheme on the same finite difference solution that you are solving for the frustum.  It is not a question of computer resources.  It would not make numerical sense to do that even if you would have the computer resources.  Your matrix would be ill-conditioned. The numerical solution (even if you had the computer resources) would be unreliable due to ill-conditioning of the matrix.

If that were necessary to do, I would use two computer models: one for the frustum and another one for the copper, that would be solved independently at each step, and the solution would be iterated at each step.  But I think that is unnecessary, since it is trivial to solve for the skin effect analytically, hence there is no need to do any numerical simulation of the skin depth, as it is well known and it can be solved analytically

Just think about it: how do you think that NASA calculated the Q, and obtained reasonable values using COMSOL Finite Element analysis?

Do you think that COMSOL modeled the skin depth (micrometer) with finite elements ?

Of course not. 

I didn't know that you were modeling the copper <<as 1/4 inch,  6.35 mm or 5 + computational cells thick >> Did I understand that right?  that you have 5 computational cells through the thickness of only 1/4 in of copper ?

Based on this, my conclusion is the following:

1) Ignore Q for these Meep analyses

2) Consider that power losses are not properly taken into account in these Meep analyses, hence steady-state is going to take much longer to be achieved in the Meep model than in reality (if ever)

3) The proper way to calculate power losses and hence Q would be to write code in Meep to introduce power losses proportional to the skin depth (which can be calculated with a simple expression) times the surface integral of the square of the magnetic field at the inner surface of the copper cavity.

_________

PS: I still think that running different values of the Drude model to come up with realistic power losses would make much more sense than the present Drude constants.  The purpose of the Drude model should be to have realistic power losses, and the present power losses are orders of magnitude smaller than what they should be.  It would be an "ad hoc" solution, purely for engineering purposes, but at least it would give realistic values of power losses.



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 07:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421226#msg1421226">Quote from: X_RaY on 08/30/2015 05:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !
I have a suggestion for the model.

Cone dimensions (CrazyEddie).
Dipole orientation like in the picture(YangShell), but more and shorter antennas around the circumference near the big end.


Note that the YangShell design with only two dipoles in this configuration showed TE01 but deformed.

In the following drawings we have 36 short dipole antennas, arranged circularly every 10° near the big base, at 22.6073% of the distance between the ends, as recommended by Rodal. How would you dispose them longitudinally (i.e. along their greatest length):
- radially,
- or circularly (tangent to the perimeter of the circle they draw)?

My guess is circularly (to simulate a loop). But in the drawing you brought with only a couple of them, it seems they are disposed radially so I think we should clarify.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/30/2015 07:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421247#msg1421247">Quote from: flux_capacitor on 08/30/2015 07:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421226#msg1421226">Quote from: X_RaY on 08/30/2015 05:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !
I have a suggestion for the model.

Cone dimensions (CrazyEddie).
Dipole orientation like in the picture(YangShell), but more and shorter antennas around the circumference near the big end.


Note that the YangShell design with only two dipoles in this configuration showed TE01 but deformed.

In the following drawings we have 36 short dipole antennas, arranged circularly every 10° near the big base, at 22.6073% of the distance between the ends, as recommended by Rodal. How would you dispose them longitudinally (i.e. along their greatest length):
- radially,
- or circularly (tangent to the perimeter of the circle they draw)?

My guess is circularly (to simulate a loop). But in the drawing you brought with only a couple of them, it seems they are disposed radially so I think we should clarify.
Circular i think. The field vectors are closer/more equal to the TE01 mode.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 07:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421258#msg1421258">Quote from: X_RaY on 08/30/2015 07:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421247#msg1421247">Quote from: flux_capacitor on 08/30/2015 07:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421226#msg1421226">Quote from: X_RaY on 08/30/2015 05:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !
I have a suggestion for the model.

Cone dimensions (CrazyEddie).
Dipole orientation like in the picture(YangShell), but more and shorter antennas around the circumference near the big end.


Note that the YangShell design with only two dipoles in this configuration showed TE01 but deformed.

In the following drawings we have 36 short dipole antennas, arranged circularly every 10° near the big base, at 22.6073% of the distance between the ends, as recommended by Rodal. How would you dispose them longitudinally (i.e. along their greatest length):
- radially,
- or circularly (tangent to the perimeter of the circle they draw)?

My guess is circularly (to simulate a loop). But in the drawing you brought with only a couple of them, it seems they are disposed radially so I think we should clarify.
Circular i think. The field vectors are closer/more equal to the TE01 mode.
The diameter of the of the 36 short antennas (the distance between the antennas in opposite locations) should be much smaller than the diameter of the truncated cone at the location of the antennas, as I showed with images previously, since the effective diameter of the axial magnetic field is much smaller than the diameter of the truncated cone.  The diameter should be based on the proportion of the images provided for the axial magnetic field.

Making the diameter too large will interfere with the transverse electric field in the azimuthal direction which would degrade the mode shape.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 07:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421242#msg1421242">Quote from: deltaMass on 08/30/2015 06:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421221#msg1421221">Quote from: aero on 08/30/2015 05:24 PM</a>
Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.
Sad to say I threw away the papers containing that work.
Then there is no basis to justify those Drude constant models presently used in the Meep analysis of the frustum: they result in power losses that are several orders of magnitude smaller than what they should be.  Q's of millions do not make any sense.   It doesn't make sense as an engineering model and it doesn't make sense as a theoretical model.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 07:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421258#msg1421258">Quote from: X_RaY on 08/30/2015 07:47 PM</a>
Circular i think. The field vectors are closer/more equal to the TE01 mode.

The Stonehenge arrangement then :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421259#msg1421259">Quote from: Rodal on 08/30/2015 07:51 PM</a>
The diameter of the of the 36 short antennas (the distance between the antennas in opposite locations) should be much smaller than the diameter of the truncated cone at the location of the antennas, as I showed with images previously, since the effective diameter of the axial magnetic field is much smaller than the diameter of the truncated cone.  The diameter should be based on the proportion of the images provided for the axial magnetic field.

Making the diameter too large will interfere with the transverse electric field in the azimuthal direction which would degrade the mode shape.

I remember. Will be difficult to put so many dipole antennas within such a small circle (about 3 to 4 cm wide if you want to make it the same size as a real loop antenna).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 08:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421261#msg1421261">Quote from: flux_capacitor on 08/30/2015 07:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421258#msg1421258">Quote from: X_RaY on 08/30/2015 07:47 PM</a>
Circular i think. The field vectors are closer/more equal to the TE01 mode.

The Stonehenge arrangement then :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421259#msg1421259">Quote from: Rodal on 08/30/2015 07:51 PM</a>
The diameter of the of the 36 short antennas (the distance between the antennas in opposite locations) should be much smaller than the diameter of the truncated cone at the location of the antennas, as I showed with images previously, since the effective diameter of the axial magnetic field is much smaller than the diameter of the truncated cone.  The diameter should be based on the proportion of the images provided for the axial magnetic field.

Making the diameter too large will interfere with the transverse electric field in the azimuthal direction which would degrade the mode shape.

I remember. Will be difficult to put so many dipole antennas within such a small circle (about 3 to 4 cm wide if you want to make it the same size as a real loop antenna).

1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/30/2015 08:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421259#msg1421259">Quote from: Rodal on 08/30/2015 07:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421258#msg1421258">Quote from: X_RaY on 08/30/2015 07:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421247#msg1421247">Quote from: flux_capacitor on 08/30/2015 07:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421226#msg1421226">Quote from: X_RaY on 08/30/2015 05:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421203#msg1421203">Quote from: Rodal on 08/30/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421202#msg1421202">Quote from: X_RaY on 08/30/2015 03:59 PM</a>
...
Good idea :)
Another way may be the useage a larger number of dipoles to form a loop like antenna structure?
I fully agree,  a large number (say every 10 degrees: 36 such antennas) of short antennas around the circumference, would ensure axi-symmetry .

Please, no straight long dipole antennas: straight long antennas distort the symmetry of the modes !
I have a suggestion for the model.

Cone dimensions (CrazyEddie).
Dipole orientation like in the picture(YangShell), but more and shorter antennas around the circumference near the big end.


Note that the YangShell design with only two dipoles in this configuration showed TE01 but deformed.

In the following drawings we have 36 short dipole antennas, arranged circularly every 10° near the big base, at 22.6073% of the distance between the ends, as recommended by Rodal. How would you dispose them longitudinally (i.e. along their greatest length):
- radially,
- or circularly (tangent to the perimeter of the circle they draw)?

My guess is circularly (to simulate a loop). But in the drawing you brought with only a couple of them, it seems they are disposed radially so I think we should clarify.
Circular i think. The field vectors are closer/more equal to the TE01 mode.
The diameter of the of the 36 short antennas (the distance between the antennas in opposite locations) should be much smaller than the diameter of the truncated cone at the location of the antennas, as I showed with images previously, since the effective diameter of the axial magnetic field is much smaller than the diameter of the truncated cone.  The diameter should be based on the proportion of the images provided for the axial magnetic field.

Making the diameter too large will interfere with the transverse electric field in the azimuthal direction which would degrade the mode shape.
There are some possibilities:
1) Place the dipoles closer to the endplate at the diameter like in the picture( big loop near the plate, half the distance to the sidewall).
2) Make the diameter smaller(like your favorite, little loop near the center at bigger distance[lambda/4]  to the end plate).
3) Near the side wall (also lambda/4 distance to the end plate)
4) At the center of the H field in that region (~half the diameter and ~lambda/4 away from the big end plate, may be the best)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/30/2015 08:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

I remember the discussion with the (too) large loop antenna and then the smaller loop antenna with its circumference being equal to λ/4, both near the big end and at the center of axi-symmetry. But I don't recall you specified a different diameter. Can you provide a link to this dimension?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

Of course. See new picture below. The 12 dipole antennas drew a circle having a diameter of 46.4 mm (I based that on λ/4 in this region) at a distance of 36.85 mm from the big base as you advised (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

We are currently trying to calculate antennas shapes and locations for Shell's 2nd generation frustum, using flat ends, powered by a 2.47 GHz magnetron at 100% duty cycle. It is true her 1st gen is a hexagonal truncated pyramid (see-shell-testbed.png),  but her 2nd gen is a truncated cone with a cylindrical neck fitting an axially adjustable small circular end, with the following dimensions:

Db = 295 mm
Ds = 160 mm
L = 163 mm (173 mm according to TT's spreadsheet, but this will be the opportunity to test the true resonant mode at various lengths, thanks to the axially adjustable small end)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 08:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269">Quote from: flux_capacitor on 08/30/2015 08:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

I remember the discussion with the (too) large loop antenna and then the smaller loop antenna with its circumference being equal to λ/4, both near the big end and at the center of axi-symmetry. But I don't recall you specified a different diameter. Can you provide a link to this dimension?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

Of course. See new picture below.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

We are currently trying to calculate antennas shapes and locations for Shell's 2nd generation frustum, using flat ends, powered by a 2.47 GHz magnetron at 100% duty cycle. It is true her 1st gen is a hexagonal truncated pyramid (see-shell-testbed.png),  but her 2nd gen is a truncated cone with a cylindrical neck fitting an axially adjustable small circular end, with the following dimensions:

Db = 295 mm
Ds = 160 mm
L = 163 mm (173 mm according to TT's spreadsheet, but this will be the opportunity to test the true resonant mode at various lengths, thanks to the axially adjustable small end)


Link:   http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419670#msg1419670

real diameter of antenna =(real diameter of cone at that location )*(diameter of red contour region in the plot below)/(diameter of cone at that location in the plot below)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059926,3Bimage.pagespeed.ic.LXpvXL1fCD.webp)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059928,3Bimage.pagespeed.ic.YHQaUjNJ5z.webp)

Concerning Shell's hexagon:  the point is that her hexagon was modeled in Meep as a perfectly round circumference, it was never modeled as a hexagon.  Conversely, it is perfectly fine to model in Meep a round  antenna as a hexagonal antenna.  What is good for the goose is good for the gander

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 08/30/2015 09:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420851#msg1420851">Quote from: Rodal on 08/29/2015 01:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420849#msg1420849">Quote from: jmossman on 08/29/2015 01:25 AM</a>
...
I don't think we know the impedance match between the magnetron and the frustum, and therefore don't know how much of the InputPower is actually getting coupled.
...
Admittedly I also don't know if reflected vs delivered power makes any difference in "thrust".... 
...

We don't have knowledge of "impedance match between the magnetron and the frustum" for most reported experiments, do we?.
...
The raw input power should also be used for rfmwguy's experiment, just as it has been done for most other experiments.
...

I concede that using raw input power would be consistent with other reported data in the twiki.

Happily Rfmwguy has agreed to push forward and try to obtain better SNR.  I agree that now is not the time to worry about detailed coupling and excitation frequency data when there are more important "bigger picture" items on the punch list.  Characterization of the balance beam, for instance.  ;D

Best wishes to the ongoing experiments!

Thanks,
James

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: frobnicat on 08/30/2015 10:57 PM
Speaking about characterization of the balance beam, "stickiness" could be due to the attachment of frustum assembly (hanging on beam) not behaving like a nice pivot. A sixth of a mm displacement (parallel to the beam) of the centre of mass of a 3kg weight hanging (not perfectly) below attachment is worth the same torque difference as an added 500mg force (at same distance from central axis).

@rfmwguy : I think this is worth investigating, could you take and post a few close-ups of the "stirrup" that holds the hanging test article on the beam ? What is the pivot looking like, is it just a dry pivot in a bored hole in the beam ? How lose is it (does it rotate easily ?). What material and geometry for the "frustum hanger" arms that extends laterally from the beam to hold the strings (?) to which the test article is suspended so that we have an idea of deformations under load (do they show some visible degree of compliance under the 3kg load) ?

Also would need an order of magnitude for the angle displacement of the beam under the test load (of 500mg is that it ?). Maybe the data is out there, sorry if I missed that already.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 11:02 PM
Doc, not sure if you want to report ft 1, ft 2 and ft 2a on wiki test results but I am ok with Null on all three, or at least possible thrust below measurement threshold. I cannot yet resolve orders of 10 mg, i'd estimate my mechanical setup to be 100 mg at best.

The laser displacement sensor coming next week will easily resolve this. Might be good idea to post letting other diy projects in on measurement resolution limits using a laser pointer system.

Your call doc...I'm good with it...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/30/2015 11:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421290#msg1421290">Quote from: rfmwguy on 08/30/2015 11:02 PM</a>
Doc, not sure if you want to report ft 1, ft 2 and ft 2a on wiki test results but I am ok with Null on all three, or at least possible thrust below measurement threshold. I cannot yet resolve orders of 10 mg, i'd estimate my mechanical setup to be 100 mg at best.

The laser displacement sensor coming next week will easily resolve this. Might be good idea to post letting other diy projects in on measurement resolution limits using a laser pointer system.

Your call doc...I'm good with it...
I very much appreciate your feedback and willingness to post the results as null.  This speaks greatly of your scientific objectivity, which I applaud.

I fully agree that the results look null so far, but since the laser displacement sensor is arriving next week, I propose we wait for its arrival, and further tests, before posting the results.  I also like frobnicat's point of examining all the pivot supports :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 08/30/2015 11:43 PM
Just a warning.
Beware adiabatic degenerated mode mixing inside tapered cavity with flat ends.
If, for a circular waveguide, there is a TE mode and a TM mode with the same beta for the same frequency omega ( degenerated modes), then under a tapered circular waveguide propagation they probaly will mixing each other.
The same occurs in bended circular waveguides.
Do not be surprised by trying inject a TE mode from one side and get a TM mode on the other side.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/30/2015 11:46 PM
Here are pics of the nsf-1701 attachments to the end of the balance beam. Stainless steel fishing leaders, 9 inches long.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/31/2015 12:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421274#msg1421274">Quote from: jmossman on 08/30/2015 09:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420851#msg1420851">Quote from: Rodal on 08/29/2015 01:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420849#msg1420849">Quote from: jmossman on 08/29/2015 01:25 AM</a>
...
I don't think we know the impedance match between the magnetron and the frustum, and therefore don't know how much of the InputPower is actually getting coupled.
...
Admittedly I also don't know if reflected vs delivered power makes any difference in "thrust".... 
...

We don't have knowledge of "impedance match between the magnetron and the frustum" for most reported experiments, do we?.
...
The raw input power should also be used for rfmwguy's experiment, just as it has been done for most other experiments.
...

I concede that using raw input power would be consistent with other reported data in the twiki.

Happily Rfmwguy has agreed to push forward and try to obtain better SNR.  I agree that now is not the time to worry about detailed coupling and excitation frequency data when there are more important "bigger picture" items on the punch list.  Characterization of the balance beam, for instance.  ;D

Best wishes to the ongoing experiments!

Thanks,
James

Personally, I would do the opposite. I would first tune that thing until I was absolutely sure I had obtained the maximum resonance and input energy, for the equipment I have. Then I would attempt to measure the thrust. Right now, how do we know there is resonance inside and a Q > 1?

The frustum is a machine. Each component must do it's thing.

1. The magnetron must output MW's. (Check)
2. The Frustum must resonate with the magnetron input to Q >> 1, verified on a bench with proper instrumentation. (TBD)
3. The balance beam must be stabilized and return position repeatable at the stabilized temperature. (TBD)
4. Laser & target must have sufficient resolution. (Check)

Once all 4 components are tested and working, then we start collecting real data. @rfmwguy has #1 and hopefully #4  resolved, with the addition of his new sensor arriving this week. Regarding #2, the frustum has not been tested sufficiently IMO. For #3, I've suggested running at about 80% duty cycle for 20 - 30 minutes, so the air temperature can stabilize. But I wouldn't do that until the frustum's resonance has been tested and characterized, so we know what state it is in when we are measuring the thrust. Without that, null results are meaningless iMO.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/31/2015 12:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421246#msg1421246">Quote from: Rodal on 08/30/2015 06:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421244#msg1421244">Quote from: aero on 08/30/2015 06:29 PM</a>
..


Thanks for explaining that Harminv starts by turning the sources off.  That makes lots of sense to me.  It didn't make sense to calculate the Q with the sources on.

It doesn't make numerical sense to model the skin depth with a finite difference scheme on the same finite difference solution that you are solving for the frustum.  It is not a question of computer resources.  It would not make numerical sense to do that even if you would have the computer resources.  Your matrix would be ill-conditioned. The numerical solution (even if you had the computer resources) would be unreliable due to ill-conditioning of the matrix.

If that were necessary to do, I would use two computer models: one for the frustum and another one for the copper, that would be solved independently at each step, and the solution would be iterated at each step.  But I think that is unnecessary, since it is trivial to solve for the skin effect analytically, hence there is no need to do any numerical simulation of the skin depth, as it is well known and it can be solved analytically

Just think about it: how do you think that NASA calculated the Q, and obtained reasonable values using COMSOL Finite Element analysis?

Do you think that COMSOL modeled the skin depth (micrometer) with finite elements ?

Of course not. 

I didn't know that you were modeling the copper <<as 1/4 inch,  6.35 mm or 5 + computational cells thick >> Did I understand that right?  that you have 5 computational cells through the thickness of only 1/4 in of copper ?

Based on this, my conclusion is the following:

1) Ignore Q for these Meep analyses

2) Consider that power losses are not properly taken into account in these Meep analyses, hence steady-state is going to take much longer to be achieved in the Meep model than in reality (if ever)

3) The proper way to calculate power losses and hence Q would be to write code in Meep to introduce power losses proportional to the skin depth (which can be calculated with a simple expression) times the surface integral of the square of the magnetic field at the inner surface of the copper cavity.

_________

PS: I still think that running different values of the Drude model to come up with realistic power losses would make much more sense than the present Drude constants.  The purpose of the Drude model should be to have realistic power losses, and the present power losses are orders of magnitude smaller than what they should be.  It would be an "ad hoc" solution, purely for engineering purposes, but at least it would give realistic values of power losses.

I agree, meep is not designed to require more than an order of magnitude variation is the cell density across the computational lattice. Trying to force it would not be fruitful.

Yes, In my model I use 1/4 inch thick copper. No good reason except to be able to see the cavity borders in the png views.

The meep user is allowed to write his/her own function for material. It is not required to use a Drude or Drude-Lorenz model so the model could do something simple like reduce the amplitude of the reflected energy at the boundary and let meep do the integration of the surface. But I am not prepared to do that. Don't know how for the first thing - That is, I don't know how to put the model into meep first, even if I could write the code you describe.

Different values of the Drude model, but we already know that Q = -Re/ i Im/2 = (power stored/power lost)/cycle = Q1 And Q1 ~= 73,000 so Q = K * Q1 where K = Q1/Q . So K ~500 and there you have it. Of course that does not help meep to reach steady state.

I think you are right, not so much ignore Q, rather use it as a yes/no answer to the question, "Does the cavity resonate in this configuration?" And then ignore it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 12:58 AM
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/31/2015 01:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421260#msg1421260">Quote from: Rodal on 08/30/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421242#msg1421242">Quote from: deltaMass on 08/30/2015 06:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421221#msg1421221">Quote from: aero on 08/30/2015 05:24 PM</a>
Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.
Sad to say I threw away the papers containing that work.
Then there is no basis to justify those Drude constant models presently used in the Meep analysis of the frustum: they result in power losses that are several orders of magnitude smaller than what they should be.  Q's of millions do not make any sense.   It doesn't make sense as an engineering model and it doesn't make sense as a theoretical model.

I think maybe I'll just go back to using perfect metal and not bother discussing Drude models and copper any further.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 01:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Yay! Good job shell. I think we've just seen our new international flight test facility for the first time  :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 01:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421307#msg1421307">Quote from: rfmwguy on 08/31/2015 01:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Yay! Good job shell. I think we've just seen our new international flight test facility for the first time  :D
My problem is I'm way way picky and I do not like to fail, it has to be the best I can do. You know the feeling. I'm just amazed at what you have done with so little...dam good work rfmwguy.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/31/2015 01:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421308#msg1421308">Quote from: SeeShells on 08/31/2015 01:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421307#msg1421307">Quote from: rfmwguy on 08/31/2015 01:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Yay! Good job shell. I think we've just seen our new international flight test facility for the first time  :D
My problem is I'm way way picky and I do not like to fail, it has to be the best I can do. You know the feeling. I'm just amazed at what you have do with so little...dam good work rfmwguy.
How much weight do you reckon will be on your balance? I ask because I see big boxy stuff!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 02:03 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421261#msg1421261">Quote from: flux_capacitor on 08/30/2015 07:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421258#msg1421258">Quote from: X_RaY on 08/30/2015 07:47 PM</a>
Circular i think. The field vectors are closer/more equal to the TE01 mode.

The Stonehenge arrangement then :)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421259#msg1421259">Quote from: Rodal on 08/30/2015 07:51 PM</a>
The diameter of the of the 36 short antennas (the distance between the antennas in opposite locations) should be much smaller than the diameter of the truncated cone at the location of the antennas, as I showed with images previously, since the effective diameter of the axial magnetic field is much smaller than the diameter of the truncated cone.  The diameter should be based on the proportion of the images provided for the axial magnetic field.

Making the diameter too large will interfere with the transverse electric field in the azimuthal direction which would degrade the mode shape.

I remember. Will be difficult to put so many dipole antennas within such a small circle (about 3 to 4 cm wide if you want to make it the same size as a real loop antenna).

1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea
Dr. Rodal. I am going to be using a round cone in this hunt for TE012, I've got the O2 free copper and I believe it will be my best shot at generating a TE012 mode. The unknown is the antenna.
EW used 1 antenna to try to stimulate a TE012 mode and we saw what of a mess it made in the modes running around like a blender on steroids. They were not symmetrical at all.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 02:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421309#msg1421309">Quote from: deltaMass on 08/31/2015 01:47 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421308#msg1421308">Quote from: SeeShells on 08/31/2015 01:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421307#msg1421307">Quote from: rfmwguy on 08/31/2015 01:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Yay! Good job shell. I think we've just seen our new international flight test facility for the first time  :D
My problem is I'm way way picky and I do not like to fail, it has to be the best I can do. You know the feeling. I'm just amazed at what you have do with so little...dam good work rfmwguy.
How much weight do you reckon will be on your balance? I ask because I see big boxy stuff!
2-3 kilos. Boxy is for stability. And please don't call my faraday cage like a friend did today. He said it looks like a chicken coop. sigh.....

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 02:17 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421306#msg1421306">Quote from: aero on 08/31/2015 01:06 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421260#msg1421260">Quote from: Rodal on 08/30/2015 07:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421242#msg1421242">Quote from: deltaMass on 08/30/2015 06:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421221#msg1421221">Quote from: aero on 08/30/2015 05:24 PM</a>
Quote
I have not seen any basis to justify the Drude constants to be realisitc for microwave frequencies.

@Deltamass - Do you want to respond to Dr. Rodal? As I recall you did devote significant effort to develop the Drude model and did use the correct range of microwave frequency in your derivation.
Sad to say I threw away the papers containing that work.
Then there is no basis to justify those Drude constant models presently used in the Meep analysis of the frustum: they result in power losses that are several orders of magnitude smaller than what they should be.  Q's of millions do not make any sense.   It doesn't make sense as an engineering model and it doesn't make sense as a theoretical model.

I think maybe I'll just go back to using perfect metal and not bother discussing Drude models and copper any further.
Is the "perfect metal" model tantamount to an infinite Q with zero resistivity ?
Is so, then I think I overdid my use of superlatives :) My intention was to get you to change the Drude model constants to get more reasonable Q's, but if the effect was that now you are going to go back to use perfect metal model, I overdid my use of superlatives.

I rather you continue using the Drude model.  I always have hopes that in the future you may run a comparison of Drude model constants and we may be able to "interpret" past results based on some rough scaling.  If you instead use a perfect metal model then that would not be possible.

The difference between 5 million and infinity is infinity.   So a calculating a finite Q, no matter how large is much preferable to calculating an infinite Q.  ;)   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 02:21 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
I'm impressed by how clean and neat everything looks !

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 02:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421315#msg1421315">Quote from: Rodal on 08/31/2015 02:21 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
I'm impressed by how clean and neat everything looks !
Thanks, just photoshopped out the dirt. :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 02:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421308#msg1421308">Quote from: SeeShells on 08/31/2015 01:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421307#msg1421307">Quote from: rfmwguy on 08/31/2015 01:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Yay! Good job shell. I think we've just seen our new international flight test facility for the first time  :D
My problem is I'm way way picky and I do not like to fail, it has to be the best I can do. You know the feeling. I'm just amazed at what you have done with so little...dam good work rfmwguy.
Its been a personal challenge to build low budget with common everyday items. Plus is that it excersises mind, minus is it needs higher resolution. No matter, I picked up a used lds sensor cheap and willl be able to see painfully small beam displacements.

I don't mind thermal lift if I can extract thrust signatures off of the curve. That remains to be seen.

You are a perfectionist, I can see that in your build. I am duly impressed as one builder to another  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 02:45 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421317#msg1421317">Quote from: rfmwguy on 08/31/2015 02:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421308#msg1421308">Quote from: SeeShells on 08/31/2015 01:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421307#msg1421307">Quote from: rfmwguy on 08/31/2015 01:17 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421305#msg1421305">Quote from: SeeShells on 08/31/2015 12:58 AM</a>
I didn't get as much time in the shop as I wanted but did get it a little more cleaned up and a couple of odds and ends done. Re-laying out the magnetron power supply. found one at Re-Store for 10 bucks and spun the % off wheel and ended up getting it for 4 bucks. ;)

I have new wire for the faraday cage arriving this tuesday and I've a few more adjustments on the leveling and vibration isolation using sorbothane pads. Got work to do on the balance beam but it is very sensitive but wants to oscillate way too much.

Here are a few pics for those who want to know.

Shell
Yay! Good job shell. I think we've just seen our new international flight test facility for the first time  :D
My problem is I'm way way picky and I do not like to fail, it has to be the best I can do. You know the feeling. I'm just amazed at what you have done with so little...dam good work rfmwguy.
Its been a personal challenge to build low budget with common everyday items. Plus is that it excersises mind, minus is it needs higher resolution. No matter, I picked up a used lds sensor cheap and willl be able to see painfully small beam displacements.

I don't mind thermal lift if I can extract thrust signatures off of the curve. That remains to be seen.

You are a perfectionist, I can see that in your build. I am duly impressed as one builder to another  8)
Thanks, that made me feel very good.

I'm hoping to be able to cross check the drive in two ways, one is with a acceleration profile and the other is force with the digital scales. Should be able to do corralations with both readings.

The thermal thrust issue is something that can  be worked out, It's a known quantity and can be calculated into the offsets needed to extract thrust figures. A little more work...meh.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 03:01 AM
Stickiness has been my thought experiment today. knife edges aside, pivoting of engine on end of beam is a very small angle but can add to roughness of curves. Already figured out a workaround but won't be able to resolve improvement until sensor gets here, so I'll hold off tinkering for now.

Biggest obstacle is the 2.83kgs of dead weight...was planning on about half that...oh well.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/31/2015 03:35 AM
You can offset some of the weight with a spring anchored vertically above.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 03:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421323#msg1421323">Quote from: deltaMass on 08/31/2015 03:35 AM</a>
You can offset some of the weight with a spring anchored vertically above.
Counter balance without adding the issues of a spring?

Shell

Tired... speeelings rong

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/31/2015 04:24 AM
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 08/31/2015 04:38 AM
Something is bugging me about the 30% power cycle from the NSF-1701 tests. The on/off cycle repeats faithfully every 25 seconds. It hums for 10 seconds and then there's 15 seconds of silence. I'm not much of a mathematician but that seems to me more like 40%. I realize hum does not equal microwave output but I imagined the two would be closely correlated. Perhaps there's an arbitrary 2.5 seconds of warm up time allowed in the calculation?

With the remote triggered, full power activation I'm sure this will become irrelevant but if anyone has a simple explanation I would be most grateful.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 11:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421330#msg1421330">Quote from: Croppa on 08/31/2015 04:38 AM</a>
Something is bugging me about the 30% power cycle from the NSF-1701 tests. The on/off cycle repeats faithfully every 25 seconds. It hums for 10 seconds and then there's 15 seconds of silence. I'm not much of a mathematician but that seems to me more like 40%. I realize hum does not equal microwave output but I imagined the two would be closely correlated. Perhaps there's an arbitrary 2.5 seconds of warm up time allowed in the calculation?

With the remote triggered, full power activation I'm sure this will become irrelevant but if anyone has a simple explanation I would be most grateful.
Tube warm up time...no doubt about it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 01:45 PM

RFMWGUY wrote (elsewhere) this great synopis:

Quote from: RFMWGUY
After 3 flight tests and several static tests, I have a few thoughts on the project. First, the forces we are trying to measure are exceedingly small; so much so, that thermal currents can easily swamp what is reportedly thrust. Second, digital scales can easily be fooled by EMI, providing false readings when the magnetron fires up. Third, this has to be approached with a neutral attitude. 
(Bold added for emphasis)

I fully agree.  Great summary.

There are previous NULL results that have not been documented in the EM Drive Wiki:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
...

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results, for example:  Mulletron's experiment who deserves to be recognized as the true leader in these Do-It-Yourself experiments, had null results documented in early threads, also the experiments with the experimenter that had constant cross-section waveguide and was using dielectric inserts, gave null results.

I understand that null results in these experiments don't close the book, as any experiment is limited on what can be tested (type of force measurement, set-up, etc.), but as Shell, says, "there is no bad data" and we should not forget those null results as well, as they are part of the big picture.

The big picture that is emerging is that if there is any EM Drive force (yes, it may be zero), its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

The force/InputPower reported by Iulian Berca was similar to the one reported by NASA.

Although RFMWGUY has not yet measured S11 or reported a Q, please notice that Mulletron (the first Do-It-Yourself) did measure and report the resonant response peaks for his truncated cone, that clearly showed resonant peak in the frequency band of the magnetron for his null experimental results (also conducted with a frustum having NASA's geometrical dimensions, excited with a magnetron centered at ~2.45 GHz).

Given these results, it would be nice to have an update from other "Do-It-Yourself" people: Elizabeth, Dr. BagelBytes, Zellerium, etc.

Zellerium's test is noteworthy, because it is conducted at a University. 

Am interpreting Zellerium correctly (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420325#msg1420325) that Zellerium's tests are also null so far ?

Quote from: Zellerium
We have been testing for a couple weeks now without any success.

(We do get frequent updates from Shell :)  )

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 02:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 02:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421398#msg1421398">Quote from: SeeShells on 08/31/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.
This is a good idea, although it may take more initial energy to get it moving because of more contact surface. I think both my galinstan and support wire assemble at end of beam might be sticky. First, I'll run a video, maybe tonight, with galinstan cups taken out of the way and simply do a 500 mg weight swing. Should be interesting.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 08/31/2015 02:30 PM
Unless you have something like diamond or ruby or sapphire at the bearing surface, the nick you get, which might be almost invisible to the naked eye, will cause stiction. I think that Shells did well not to cannibalise her jewelry for the cause  8)

ETA The Mettler H10 uses sapphire bearings.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 02:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421405#msg1421405">Quote from: rfmwguy on 08/31/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421398#msg1421398">Quote from: SeeShells on 08/31/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.
This is a good idea, although it may take more initial energy to get it moving because of more contact surface. I think both my galinstan and support wire assemble at end of beam might be sticky. First, I'll run a video, maybe tonight, with galinstan cups taken out of the way and simply do a 500 mg weight swing. Should be interesting.

I agree with deltaMass that the stiction is most probably coming from the metal to metal contact points (due to plastic deformation, beyond the yield limit of the material, and stick-friction).   

 It would be helpful to lubricate with motor oil the contacting surfaces prior to contact. Most metal to metal roller bearings, are lubricated and never run dry, even though the contact surfaces are made with hardened metals and the radii of curvature are carefully designed to avoid plastic yielding

Analyses as well as experiments of contact surfaces show how important is lubrication at contact points !!!

Remember to re-lubricate prior to each and every tests

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 02:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421393#msg1421393">Quote from: Rodal on 08/31/2015 01:45 PM</a>
RFMWGUY wrote (elsewhere) this great synopis:

Quote from: RFMWGUY
After 3 flight tests and several static tests, I have a few thoughts on the project. First, the forces we are trying to measure are exceedingly small; so much so, that thermal currents can easily swamp what is reportedly thrust. Second, digital scales can easily be fooled by EMI, providing false readings when the magnetron fires up. Third, this has to be approached with a neutral attitude. 
(Bold added for emphasis)

I fully agree.  Great summary.

There are previous NULL results that have not been documented in the EM Drive Wiki:

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420668#msg1420668">Quote from: Rodal on 08/28/2015 03:10 PM</a>
...

There are also experiments that have already been done, that had null results but have not yet been properly documented in the EM Drive wiki for experimental results, for example:  Mulletron's experiment who deserves to be recognized as the true leader in these Do-It-Yourself experiments, had null results documented in early threads, also the experiments with the experimenter that had constant cross-section waveguide and was using dielectric inserts, gave null results.

I understand that null results in these experiments don't close the book, as any experiment is limited on what can be tested (type of force measurement, set-up, etc.), but as Shell, says, "there is no bad data" and we should not forget those null results as well, as they are part of the big picture.

The big picture that is emerging is that if there is any EM Drive force (yes, it may be zero), its force/InputPower magnitude is of the very small magnitude reported by NASA (~0.001 Newton/KiloWatt) and by Dresden University (Tajmar) (0.00003 to 0.00013 Newton/KiloWatt) but not at all the thousands of times greater magnitudes reported by Shawyer (0.4 Newton/KiloWatt)  and Yang (1 Newton/KiloWatt) - who nobody has been able to reproduce-

The force/InputPower reported by Iulian Berca was similar to the one reported by NASA.

The Do-It-Yourself experiments are showing that if there is a thrust force, it is at most of the order of what has been reported by NASA and Tajmar (0.001 Newton/KiloWatt or less) rather than what has been reported by Shawyer and Yang (0.4 to 1 Newton/KiloWatt -- that nobody else has reproduced).  Although RFMWGUY has not yet measured S11 or reported a Q, please notice that Mulletron (the first Do-It-Yourself) did measure and report the resonant response peaks for his truncated cone, that clearly showed resonant peaks for his null experimental results.

This is reminding me more and more of the "cold fusion" experimental attempts at replication after the non-properly-peer-reviewed announcement from Fleischmann and Pons (which also has in common that currently, 25 years afterwards, still there is no accepted theoretical model by the mainstream scientific community which would allow cold fusion to occur)....

Quote
Many scientists tried to replicate the experiment with the few details available. Hopes faded due to the large number of negative replications, the withdrawal of many positive replications, the discovery of flaws and sources of experimental error in the original experiment,

Given these results, it would be nice to have an update from other "Do-It-Yourself" people: Elizabeth, Dr. BagelBytes, etc.

I'm hoping to take all these maybes, nopes, successes and the reasons why and learn from them. And your right as scientists, engineers, tech and lay people there is no bad data and this is why I hope everyone reports go or no go. Not to say they failed or succeeded but to gather data to refine a better test.

Heat in frustum
Planned to insert a heating element into the frustum to get a temperature profile with the buoyancy factors. Looking for a used iphone 5 or 5s to couple with a Flir 1 to verify the heat signatures of the mode generation.

Stiction
Rolling knife edge to eliminate stiction or what there is and be able to add it to the data. Currently verifying using scales that it is below .01 gram.

Stray magnetic and EM fields in the Frustum
No magnetron on the Frustum, it will be isolated in a faraday cage alone.

Rf  or Magnetics effecting the scales
0.1020 grams is .001/NW. My scales read .001 grams
they are going to be isolated when I'm done from any power, RF and magnetic sources with a faraday cage of their own made of magnetic steel mesh connected to the fulcrum arm with a small non-conducting shaft.

----_-------- fulcrum
___|____ pin actuator through the steel mesh
     |
*******  scales

Other Stray or generated EM fields
Wires are shielded or twisted pairs. Will use the spectrum analyser to log any RF 0-3.3 GHz

Vibrations
Will log the local area vibrations along with the profiles of the Drive using two lasers on the target. One laser (green) on the targeted graph paper set on top of the target box shooting to a first surface mirror on the center of the fulcrum back to the paper. The second laser (red) will be on the end of the beam opposite the frustum shooting to a first surface mirror back to the target. This gives me a baseline of incident vibrations. 

Voltage Fluctuations
Will monitor the AC voltages to the test area.

Plus all the other basic date, time, location, humidity, phase of the moon will be logged.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 03:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421406#msg1421406">Quote from: deltaMass on 08/31/2015 02:30 PM</a>
Unless you have something like diamond or ruby or sapphire at the bearing surface, the nick you get, which might be almost invisible to the naked eye, will cause stiction. I think that Shells did well not to cannibalise her jewelry for the cause  8)

ETA The Mettler H10 uses sapphire bearings.
Sure it can be a issue and I will not cannibalize any of my costume jewelery either. :D

First I'm profiling the rolling edge down to .01 gram and so far I haven't seen any above that.

Second you could see the edge of the beam encountering a "bump" if the edge was surfaced along the length or parallel to the ^ edge. It was surfaced always in the direction that the beam travels so any microscopic "groves" are in the direction of travel.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 03:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421410#msg1421410">Quote from: Rodal on 08/31/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421405#msg1421405">Quote from: rfmwguy on 08/31/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421398#msg1421398">Quote from: SeeShells on 08/31/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.
This is a good idea, although it may take more initial energy to get it moving because of more contact surface. I think both my galinstan and support wire assemble at end of beam might be sticky. First, I'll run a video, maybe tonight, with galinstan cups taken out of the way and simply do a 500 mg weight swing. Should be interesting.

I agree with deltaMass that the stiction is most probably coming from the metal to metal contact points (due to plastic deformation, beyond the yield limit of the material, and stick-friction).   

 It would be helpful to lubricate with motor oil the contacting surfaces prior to contact. Most metal to metal roller bearings, are lubricated and never run dry, even though the contact surfaces are made with hardened metals and the radii of curvature are carefully designed to avoid plastic yielding

Analyses as well as experiments of contact surfaces show how important is lubrication at contact points !!!

Remember to re-lubricate prior to each and every tests

No motor oil! It's sticky, collects dirt and dust. Dry graphite film.
http://www.instructables.com/id/How-to-Lubricate-a-Lock-Using-Graphite-From-a-Penc/

Shell
Added: Slick huh?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 03:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421422#msg1421422">Quote from: SeeShells on 08/31/2015 03:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421410#msg1421410">Quote from: Rodal on 08/31/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421405#msg1421405">Quote from: rfmwguy on 08/31/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421398#msg1421398">Quote from: SeeShells on 08/31/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.
This is a good idea, although it may take more initial energy to get it moving because of more contact surface. I think both my galinstan and support wire assemble at end of beam might be sticky. First, I'll run a video, maybe tonight, with galinstan cups taken out of the way and simply do a 500 mg weight swing. Should be interesting.

I agree with deltaMass that the stiction is most probably coming from the metal to metal contact points (due to plastic deformation, beyond the yield limit of the material, and stick-friction).   

 It would be helpful to lubricate with motor oil the contacting surfaces prior to contact. Most metal to metal roller bearings, are lubricated and never run dry, even though the contact surfaces are made with hardened metals and the radii of curvature are carefully designed to avoid plastic yielding

Analyses as well as experiments of contact surfaces show how important is lubrication at contact points !!!

Remember to re-lubricate prior to each and every tests

No motor oil! It's sticky, collects dirt and dust. Dry graphite film.
http://www.instructables.com/id/How-to-Lubricate-a-Lock-Using-Graphite-From-a-Penc/

Shell
Added: Slick huh?
EDIT: Assuming that RFMWguy has metal to metal contacting surfaces...

Those issues can be addressed by re-lubrication prior to each and every test.  Graphite is better than nothing (apparently the situation at the moment) but much inferior to oil lubrication not only as shown in my industrial experience but also in myriads of industrial applications.

The "dirt" collected by oil at the contact surface is not just from the environment but it is due to wear and micro-fracturing of the contacting surface asperities:  it is an essential benefit of a viscous liquid lubricant like oil to collect and hence remove those particles from the contact surface   Graphite (since it is not a liquid) does not provide liquid lubrication and hence it is not as effective.

Graphite is one solution when the application cannot afford to have oil injection and filtering, but in this case is there a problem with re-lubricating every time?

Try both methods (oil lubrication and graphite) and compare the results (both are going to be certainly better than dry contact :) )

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 03:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269">Quote from: flux_capacitor on 08/30/2015 08:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

I remember the discussion with the (too) large loop antenna and then the smaller loop antenna with its circumference being equal to λ/4, both near the big end and at the center of axi-symmetry. But I don't recall you specified a different diameter. Can you provide a link to this dimension?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

Of course. See new picture below. The 12 dipole antennas drew a circle having a diameter of 46.4 mm (I based that on λ/4 in this region) at a distance of 36.85 mm from the big base as you advised (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

We are currently trying to calculate antennas shapes and locations for Shell's 2nd generation frustum, using flat ends, powered by a 2.47 GHz magnetron at 100% duty cycle. It is true her 1st gen is a hexagonal truncated pyramid (see-shell-testbed.png),  but her 2nd gen is a truncated cone with a cylindrical neck fitting an axially adjustable small circular end, with the following dimensions:

Db = 295 mm
Ds = 160 mm
L = 163 mm (173 mm according to TT's spreadsheet, but this will be the opportunity to test the true resonant mode at various lengths, thanks to the axially adjustable small end)

Interesting idea worthy of sacrificing a few brain cells using the 12 vertically raised dipoles.

The first thing that I thought was how will the vertical sections deform the mode pattern? as it seems it will "wall off" the center section changing cavity tune.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 03:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421429#msg1421429">Quote from: Rodal on 08/31/2015 03:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421422#msg1421422">Quote from: SeeShells on 08/31/2015 03:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421410#msg1421410">Quote from: Rodal on 08/31/2015 02:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421405#msg1421405">Quote from: rfmwguy on 08/31/2015 02:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421398#msg1421398">Quote from: SeeShells on 08/31/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.
This is a good idea, although it may take more initial energy to get it moving because of more contact surface. I think both my galinstan and support wire assemble at end of beam might be sticky. First, I'll run a video, maybe tonight, with galinstan cups taken out of the way and simply do a 500 mg weight swing. Should be interesting.

I agree with deltaMass that the stiction is most probably coming from the metal to metal contact points (due to plastic deformation, beyond the yield limit of the material, and stick-friction).   

 It would be helpful to lubricate with motor oil the contacting surfaces prior to contact. Most metal to metal roller bearings, are lubricated and never run dry, even though the contact surfaces are made with hardened metals and the radii of curvature are carefully designed to avoid plastic yielding

Analyses as well as experiments of contact surfaces show how important is lubrication at contact points !!!

Remember to re-lubricate prior to each and every tests

No motor oil! It's sticky, collects dirt and dust. Dry graphite film.
http://www.instructables.com/id/How-to-Lubricate-a-Lock-Using-Graphite-From-a-Penc/

Shell
Added: Slick huh?
Those issues can be addressed by re-lubrication prior to each and every test.  Graphite is better than nothing (apparently the situation at the moment) but much inferior to oil lubrication not only as shown in my industrial experience but also in myriads of industrial applications.

The "dirt" collected by oil at the contact surface is not just from the environment but it is due to wear and micro-fracturing of the contacting surface asperities:  it is an essential benefit of a viscous liquid lubricant like oil to collect and hence remove those particles from the contact surface   Graphite (since it is not a liquid) does not provide liquid lubrication and hence it is not as effective.

Graphite is one solution when the application cannot afford to have oil injection and filtering, but in this case is there a problem with re-lubricating every time?

Try both methods (oil lubrication and graphite) and compare the results (both are going to be certainly better than dry contact :) )

Yes Dr. Rodel but I have a composite graphite rod sliding on graphite. Slick or not?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 04:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421433#msg1421433">Quote from: SeeShells on 08/31/2015 03:58 PM</a>
...

Yes Dr. Rodel but I have a composite graphite rod sliding on graphite. Slick or not?

Shell
Oh, OK :)

I was referring to oil lubrication of metal-to-metal contact (isn't that what RFMWguy has?), not to composite to metal contact.
What is the polymer matrix for the graphite fibers, is it epoxy?  Is it contacting metal?
Besides graphite powder you could also try Teflon (PTFE) on the contacting surface.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 04:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421439#msg1421439">Quote from: Rodal on 08/31/2015 04:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421433#msg1421433">Quote from: SeeShells on 08/31/2015 03:58 PM</a>
...

Yes Dr. Rodel but I have a composite graphite rod sliding on graphite. Slick or not?

Shell
Oh, OK :)

I was referring to oil lubrication of metal-to-metal contact (isn't that what RFMWguy has?), not to composite to metal contact.
What is the polymer matrix for the graphite fibers, is it epoxy?  Is it contacting metal?
Besides graphite powder you could also try Teflon (PTFE) on the contacting surface.
http://www.cstsales.com/carbon_rods.html

PTFE is a very neat material and quite slick, I used it in the semi areana.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 04:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421444#msg1421444">Quote from: SeeShells on 08/31/2015 04:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421439#msg1421439">Quote from: Rodal on 08/31/2015 04:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421433#msg1421433">Quote from: SeeShells on 08/31/2015 03:58 PM</a>
...

Yes Dr. Rodel but I have a composite graphite rod sliding on graphite. Slick or not?

Shell
Oh, OK :)

I was referring to oil lubrication of metal-to-metal contact (isn't that what RFMWguy has?), not to composite to metal contact.
What is the polymer matrix for the graphite fibers, is it epoxy?  Is it contacting metal?
Besides graphite powder you could also try Teflon (PTFE) on the contacting surface.
http://www.cstsales.com/carbon_rods.html

Yeah,  according to the data sheets, they are using Bisphenol F Epoxy resin with a Tg of at least 100 Deg C at a fiber to resin ratio of 67%

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 04:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421447#msg1421447">Quote from: Rodal on 08/31/2015 04:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421444#msg1421444">Quote from: SeeShells on 08/31/2015 04:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421439#msg1421439">Quote from: Rodal on 08/31/2015 04:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421433#msg1421433">Quote from: SeeShells on 08/31/2015 03:58 PM</a>
...

Yes Dr. Rodel but I have a composite graphite rod sliding on graphite. Slick or not?

Shell
Oh, OK :)

I was referring to oil lubrication of metal-to-metal contact (isn't that what RFMWguy has?), not to composite to metal contact.
What is the polymer matrix for the graphite fibers, is it epoxy?  Is it contacting metal?
Besides graphite powder you could also try Teflon (PTFE) on the contacting surface.
http://www.cstsales.com/carbon_rods.html

Yeah,  according to the data sheets, they are using Bisphenol F Epoxy resin with a Tg of at least 100 Deg C at a fiber to resin ratio of 67%
They order it from a company in Switzerland and so far I'm very impressed with it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/31/2015 05:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421432#msg1421432">Quote from: SeeShells on 08/31/2015 03:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269">Quote from: flux_capacitor on 08/30/2015 08:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

I remember the discussion with the (too) large loop antenna and then the smaller loop antenna with its circumference being equal to λ/4, both near the big end and at the center of axi-symmetry. But I don't recall you specified a different diameter. Can you provide a link to this dimension?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

Of course. See new picture below. The 12 dipole antennas drew a circle having a diameter of 46.4 mm (I based that on λ/4 in this region) at a distance of 36.85 mm from the big base as you advised (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

We are currently trying to calculate antennas shapes and locations for Shell's 2nd generation frustum, using flat ends, powered by a 2.47 GHz magnetron at 100% duty cycle. It is true her 1st gen is a hexagonal truncated pyramid (see-shell-testbed.png),  but her 2nd gen is a truncated cone with a cylindrical neck fitting an axially adjustable small circular end, with the following dimensions:

Db = 295 mm
Ds = 160 mm
L = 163 mm (173 mm according to TT's spreadsheet, but this will be the opportunity to test the true resonant mode at various lengths, thanks to the axially adjustable small end)

Interesting idea worthy of sacrificing a few brain cells using the 12 vertically raised dipoles.

The first thing that I thought was how will the vertical sections deform the mode pattern? as it seems it will "wall off" the center section changing cavity tune.
You are right with the vertical feed lines.
The original idea was to simulate a loop like antenna structure with a number of dipoles, not really the stonehenge style antenna forest.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 05:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421450#msg1421450">Quote from: SeeShells on 08/31/2015 04:46 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421447#msg1421447">Quote from: Rodal on 08/31/2015 04:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421444#msg1421444">Quote from: SeeShells on 08/31/2015 04:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421439#msg1421439">Quote from: Rodal on 08/31/2015 04:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421433#msg1421433">Quote from: SeeShells on 08/31/2015 03:58 PM</a>
...

Yes Dr. Rodel but I have a composite graphite rod sliding on graphite. Slick or not?

Shell
Oh, OK :)

I was referring to oil lubrication of metal-to-metal contact (isn't that what RFMWguy has?), not to composite to metal contact.
What is the polymer matrix for the graphite fibers, is it epoxy?  Is it contacting metal?
Besides graphite powder you could also try Teflon (PTFE) on the contacting surface.
http://www.cstsales.com/carbon_rods.html

Yeah,  according to the data sheets, they are using Bisphenol F Epoxy resin with a Tg of at least 100 Deg C at a fiber to resin ratio of 67%
They order it from a company in Switzerland and so far I'm very impressed with it.
You get kudos for selecting a product made with a pultrusion method, which is definitely the best manufacturing method to get high fiber to resin ratio for long rods, ensuring maximum bending stiffness/weight.  The carbon fiber was made in Japan (they use Toho or Torayca as the carbon fiber supplier).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/31/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421456#msg1421456">Quote from: X_RaY on 08/31/2015 05:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421432#msg1421432">Quote from: SeeShells on 08/31/2015 03:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269">Quote from: flux_capacitor on 08/30/2015 08:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

I remember the discussion with the (too) large loop antenna and then the smaller loop antenna with its circumference being equal to λ/4, both near the big end and at the center of axi-symmetry. But I don't recall you specified a different diameter. Can you provide a link to this dimension?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

Of course. See new picture below. The 12 dipole antennas drew a circle having a diameter of 46.4 mm (I based that on λ/4 in this region) at a distance of 36.85 mm from the big base as you advised (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

We are currently trying to calculate antennas shapes and locations for Shell's 2nd generation frustum, using flat ends, powered by a 2.47 GHz magnetron at 100% duty cycle. It is true her 1st gen is a hexagonal truncated pyramid (see-shell-testbed.png),  but her 2nd gen is a truncated cone with a cylindrical neck fitting an axially adjustable small circular end, with the following dimensions:

Db = 295 mm
Ds = 160 mm
L = 163 mm (173 mm according to TT's spreadsheet, but this will be the opportunity to test the true resonant mode at various lengths, thanks to the axially adjustable small end)

Interesting idea worthy of sacrificing a few brain cells using the 12 vertically raised dipoles.

The first thing that I thought was how will the vertical sections deform the mode pattern? as it seems it will "wall off" the center section changing cavity tune.
You are right with the vertical feed lines.
The original idea was to simulate a loop like antenna structure with a number of dipoles, not really the stonehenge style antenna forest.

This is a concern but how to connect those multiple dipole antennas to the frustum and the exterior? If you bring the vertical feed lines radially from the side walls they are no longer a "forest" but they become even longer and would look like bicycle spokes.

From this point of view a real loop antenna would be better indeed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 08/31/2015 06:20 PM
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 08/31/2015 06:23 PM

Thought is that the time constants are associated more with the PLR and time it takes for the magnetron/frustrum to reach resonance as opposed to the "EM-Drive/Q-Thruster" phenomena (if real). If we are seeing Conservation of Momentum than this should occur basically at the speed of light. At 5MW with an industrial magnetron transmitter we will achieve resonance for sure within the 10us, and will demonstrate that by first measuring Q prior to attempting any measurement of thrust. Concern however is if Conservation of Momentum depends on "fluidization of the quantum vacuum"; again, does this occur at the speed of light or do we require cycles and if so, how many? The follow up 100kW continuous trial will then follow, just working on the frustrum cooling system (nitrogen).


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420854#msg1420854">Quote from: zen-in on 08/29/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420810#msg1420810">Quote from: CraigPichach on 08/28/2015 10:27 PM</a>
Ironically there is a unit set up to do 5MW pulses that can adjust frequency within 10MHz of 930MHz ( frustum dimensions would not have to be exact that we could find resonance). At 10 microseconds the cooling of the frustum is managable without online cooling. Issue is would you see something in 10microseconds? Such a test hopefully could produce results that are an order of magnitude above background (into the ground no buoyant effects) or allow other phenomena (photon thruster leakage?) to be measurable. This will probably be experiment one as it is relatively cheap. If it's CoM I expect to see something on a digital scale within those 10us.

It's the duty cycle that matters in this case.   If the 10 uS pulse happens once a Sec. you have a duty cycle of  .001% and a time averaged power of 50 Watts, which is close to the power level the NASA team used.   Because the mass you are trying to move is so much larger you would see less EM-Drive thrust (if it really exists) but you would also get more thermal, magnetic, and electrostatic effects.   All of the EM-Drive "thrust" signatures disclosed so far have large time constants.   So the effect of each individual 5 MW pulse would not be observable.   This is just my opinion.  I haven't done any EM-Drive experiments.  I have been told I will soon be eating my words.   I am still waiting...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 06:25 PM
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/31/2015 06:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421480#msg1421480">Quote from: flux_capacitor on 08/31/2015 06:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421456#msg1421456">Quote from: X_RaY on 08/31/2015 05:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421432#msg1421432">Quote from: SeeShells on 08/31/2015 03:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269">Quote from: flux_capacitor on 08/30/2015 08:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
1) The diameter given by the images I provided is still significantly larger than the diameter of the loop used by NASA on the side of the cone (that was not successful at producing TE012 on a consistent basis, hence they had to switch to TM212 transverse magnetic mode).

I remember the discussion with the (too) large loop antenna and then the smaller loop antenna with its circumference being equal to λ/4, both near the big end and at the center of axi-symmetry. But I don't recall you specified a different diameter. Can you provide a link to this dimension?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
2) If 36 antennas results in too many antennas of too short length each, then let's use common sense, and just reduce the number of antennas based on a sensible short length.  Having 18 antennas is much better than having one straight antenna.  Even 6 antennas is better than one straight antenna :)

Of course. See new picture below. The 12 dipole antennas drew a circle having a diameter of 46.4 mm (I based that on λ/4 in this region) at a distance of 36.85 mm from the big base as you advised (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419037#msg1419037).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421262#msg1421262">Quote from: Rodal on 08/30/2015 08:00 PM</a>
3) As I understand it, Shell is not going to use a circular frustum anyway, but is going to use a polygon.   I forgot how many sides. Let's say that Shell is going to use a hexagon, then use 6 antennas.  If Shell uses a pentagon, use 5 antennas.  If Shell uses a heptagon, use 7 antenas.  You get the idea

We are currently trying to calculate antennas shapes and locations for Shell's 2nd generation frustum, using flat ends, powered by a 2.47 GHz magnetron at 100% duty cycle. It is true her 1st gen is a hexagonal truncated pyramid (see-shell-testbed.png),  but her 2nd gen is a truncated cone with a cylindrical neck fitting an axially adjustable small circular end, with the following dimensions:

Db = 295 mm
Ds = 160 mm
L = 163 mm (173 mm according to TT's spreadsheet, but this will be the opportunity to test the true resonant mode at various lengths, thanks to the axially adjustable small end)

Interesting idea worthy of sacrificing a few brain cells using the 12 vertically raised dipoles.

The first thing that I thought was how will the vertical sections deform the mode pattern? as it seems it will "wall off" the center section changing cavity tune.
You are right with the vertical feed lines.
The original idea was to simulate a loop like antenna structure with a number of dipoles, not really the stonehenge style antenna forest.

This is a concern but how to connect those multiple dipole antennas to the frustum and the exterior? If you bring the vertical feed lines radially from the side walls they are no longer a "forest" but they become even longer and would look like bicycle spokes.

From this point of view a real loop antenna would be better indeed.
For the simulation of a loop in a program like meep it may be possible to place a number of dipoles, one behind the other, to form a virtual wire. Around that path the magnetic field looks like the field around a real wire with a current flow.
In the real world use a real wire to form the real loop.

I don't say the dipoles wouldn't work in real, but could be hard to build and tune each single antenna.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 06:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/31/2015 06:50 PM
@rfmwguy

You could use a electrical heat source close to the magnetron position in your setup, and than look what the laserpoint does while a blind test... :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 06:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 07:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421490#msg1421490">Quote from: X_RaY on 08/31/2015 06:50 PM</a>
@rfmwguy

You could use a electrical heat source close to the magnetron position in your setup, and than look what the laserpoint does while a blind test... :)
Yes, I'm about to steal my wife's Cuisinart Grille and put underneath the frustum...Oh-oh...now I've done it...she reads my posts sometimes.  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kencolangelo on 08/31/2015 07:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

I wonder if some of the massive server/PC copper heatsinks would be a good idea? They're commodity items, I've even got some giant ones lying around, free to a good home.
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=copper+heatsink&N=4115&isNodeId=1 (http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=copper+heatsink&N=4115&isNodeId=1)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 08/31/2015 07:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421491#msg1421491">Quote from: Rodal on 08/31/2015 06:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

A 0.915 GHz magnetron would have some benefits: the frustum would be slightly bigger to built, but the tolerance to achieve and maintain resonance would be easier than on a smaller frustum.

But at such a cost (how much?) for very high power, say a hundred to thousands of kilowatts, I wonder why those labs (like CraigPichach's university (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420716#msg1420716)) do not plan to use a much cleaner source of microwaves instead, like a klystron, which offers both high power and narrow band.

Magnetrons are ok because they are compact and that the 2.45 GHz models from ovens are really cheap. But with enough $$$ and other frequencies investigated, I think TWTAs and klystrons would do a better job.

EDIT: Whatever I'd love to see an experiment with an N2-cooled frustum powered by a 100kW-class liquid-cooled magnetron! This would be waaaay beyond what we saw even from Shawyer. :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 08/31/2015 08:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421504#msg1421504">Quote from: flux_capacitor on 08/31/2015 07:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421491#msg1421491">Quote from: Rodal on 08/31/2015 06:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

A 0.915 GHz magnetron would have some benefits: the frustum would be slightly bigger to built, but the tolerance to achieve and maintain resonance would be easier than on a smaller frustum.

But at such a cost (how much?) I wonder why the labs do not plan to use a much cleaner source of microwaves instead, like a klystron, which offers both high power and narrow band.

Magnetrons are ok because they are compact and that the 2.45 GHz models from ovens are really cheap. But with enough $$$ and other frequencies investigated, I think TWTAs and klystrons would do a better job.
Even better would be a high power maser. Think about the 3dB BW (~1 Hz) and the Q  ::)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 08/31/2015 08:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421484#msg1421484">Quote from: CraigPichach on 08/31/2015 06:23 PM</a>
Thought is that the time constants are associated more with the PLR and time it takes for the magnetron/frustrum to reach resonance as opposed to the "EM-Drive/Q-Thruster" phenomena (if real). If we are seeing Conservation of Momentum than this should occur basically at the speed of light. At 5MW with an industrial magnetron transmitter we will achieve resonance for sure within the 10us, and will demonstrate that by first measuring Q prior to attempting any measurement of thrust. Concern however is if Conservation of Momentum depends on "fluidization of the quantum vacuum"; again, does this occur at the speed of light or do we require cycles and if so, how many? The follow up 100kW continuous trial will then follow, just working on the frustrum cooling system (nitrogen).


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420854#msg1420854">Quote from: zen-in on 08/29/2015 01:42 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420810#msg1420810">Quote from: CraigPichach on 08/28/2015 10:27 PM</a>
Ironically there is a unit set up to do 5MW pulses that can adjust frequency within 10MHz of 930MHz ( frustum dimensions would not have to be exact that we could find resonance). At 10 microseconds the cooling of the frustum is managable without online cooling. Issue is would you see something in 10microseconds? Such a test hopefully could produce results that are an order of magnitude above background (into the ground no buoyant effects) or allow other phenomena (photon thruster leakage?) to be measurable. This will probably be experiment one as it is relatively cheap. If it's CoM I expect to see something on a digital scale within those 10us.

It's the duty cycle that matters in this case.   If the 10 uS pulse happens once a Sec. you have a duty cycle of  .001% and a time averaged power of 50 Watts, which is close to the power level the NASA team used.   Because the mass you are trying to move is so much larger you would see less EM-Drive thrust (if it really exists) but you would also get more thermal, magnetic, and electrostatic effects.   All of the EM-Drive "thrust" signatures disclosed so far have large time constants.   So the effect of each individual 5 MW pulse would not be observable.   This is just my opinion.  I haven't done any EM-Drive experiments.  I have been told I will soon be eating my words.   I am still waiting...

Did I see an earlier description about a "digital scale" as the intended measurement method during these 10uS pulses?  If so, I would think a different method for measuring movement will be needed;  hard to imagine the time constants associated with a "digital scale" will be compatible with sub-100-millisecond, let alone something as fleeting as 10uS.

High resolution laser measurement would be nearly the only thing I could imagine capable of capturing effects of such a vanishingly small pulse in a 10uS timeframe;  the apparatus isn't likely to move very far (maybe just "vibrate" due to inability to overcome static friction of bearings, etc).  Plus, if the "thrust" effect is real, the stresses from a 5MW pulse on the materials of the frustum are an unknown...  would they flex and deform like a spring, thereby dampening or potentially eliminating any measurable effect?  My line of thought is that engineering a device to be able to operate at 5MW might involve more than just a microwave source, cavity shape/bandwidth, and good thermal management.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/31/2015 09:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 08/31/2015 09:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421491#msg1421491">Quote from: Rodal on 08/31/2015 06:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

I think it's not just the temperature of the Magentron that is heating the air, but also the microwaves heating the water vapor in the air. So simply removing the heat caused by the hot metals is only half the problem. I think it would be easier to remove the air. :)
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 09:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421495#msg1421495">Quote from: rfmwguy on 08/31/2015 07:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421490#msg1421490">Quote from: X_RaY on 08/31/2015 06:50 PM</a>
@rfmwguy

You could use a electrical heat source close to the magnetron position in your setup, and than look what the laserpoint does while a blind test... :)
Yes, I'm about to steal my wife's Cuisinart Grille and put underneath the frustum...Oh-oh...now I've done it...she reads my posts sometimes.  :o

hahahahaa whew, that's very funny! I found one from a heating plate at the Re-Store used home equip for $3 bucks.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 08/31/2015 09:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd

Yes, we all knew from the beginning that the best thing is to use a circular loop and that was the starting recommendation, but he doesn't know how to input a circular loop in Meep, only knows how to input straight dipole antennas.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
,,,I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction....

...

To understand that you have to start with the fact that so far, the only way that aero's Meep was able to excite a TE mode was by using two (2) long straight parallel dipole antennas.   The problem with 2 long straight ones is that the TE012 mode excited was anisotropic (it looks like TE012 in only one plane).  To excite an axi-symmetric TE012 mode, one needs to have a high n-multiple, instead of n=2.  Mathematically, a circle is a polygon with n sides where n approaches Infinity.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
...For TE012, there are only 2 poles around the circle...
That's incorrect.

The convention is TEmnp where m=circular, n= polar, p = longitudinal

Thus TE012 has m=0 which means constant field in the circular (azimuthal) direction.

p=2 means two wave-patterns in the longitudinal direction

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kencolangelo on 08/31/2015 09:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421523#msg1421523">Quote from: WarpTech on 08/31/2015 09:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421491#msg1421491">Quote from: Rodal on 08/31/2015 06:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

I think it's not just the temperature of the Magentron that is heating the air, but also the microwaves heating the water vapor in the air. So simply removing the heat caused by the hot metals is only half the problem. I think it would be easier to remove the air. :)
Todd
Maybe remove the water in the air?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 08/31/2015 09:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd
I'm going to give you a piece or rope attached at one end to a plate 6 foot long. Your job if you should decide to accept Mr. Todd is to make the rope oscillate harmonically in a sustained wave pattern. Easy? Right. Any school kid will tell you that it is that has ever watched someone jumping rope. Now I going to put that rope in a cone shaped cavity where the osculating peaks of the waves hit the side walls of the cone shape. Your job is to find not only a standing wave up and down the rope length that is the same peak to peak but a particular one, at a particular frequency and rotating just so.

No, it's not that simple.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 09:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421533#msg1421533">Quote from: kencolangelo on 08/31/2015 09:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421523#msg1421523">Quote from: WarpTech on 08/31/2015 09:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421491#msg1421491">Quote from: Rodal on 08/31/2015 06:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

I think it's not just the temperature of the Magentron that is heating the air, but also the microwaves heating the water vapor in the air. So simply removing the heat caused by the hot metals is only half the problem. I think it would be easier to remove the air. :)
Todd
Maybe remove the water in the air?
Yes, this fall and winter will be much better. All tests done had RH about 50-59%, which is common this time of the year. Funny though, I've never measure much of a heat rise on the frustum side or plate opposite magnetron just after a test. The mesh should dissipate heated air quickly.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 08/31/2015 10:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421536#msg1421536">Quote from: SeeShells on 08/31/2015 09:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd
I'm going to give you a piece or rope attached at one end to a plate 6 foot long. Your job if you should decide to accept Mr. Todd is to make the rope oscillate harmonically in a sustained wave pattern. Easy? Right. Any school kid will tell you that it is that has ever watched someone jumping rope. Now I going to put that rope in a cone shaped cavity where the osculating peaks of the waves hit the side walls of the cone shape. Your job is to find not only a standing wave up and down the rope length that is the same peak to peak but a particular one, at a particular frequency and rotating just so.

No, it's not that simple.

Also, MEEP is not the easiest software to model arbritarily shaped antennae.  This is the place where the MEEPers think that everyone should write their own function...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 08/31/2015 10:39 PM
DailyKos...last place I thought I'd get some emdrive press  :o

http://www.dailykos.com/story/2015/08/26/1415532/-EmDrive-Jesus-What-a-Day#
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: venir on 08/31/2015 11:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421548#msg1421548">Quote from: rfmwguy on 08/31/2015 10:39 PM</a>
DailyKos...last place I thought I'd get some emdrive press  :o

http://www.dailykos.com/story/2015/08/26/1415532/-EmDrive-Jesus-What-a-Day#

Even if they can't get your handle right  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 08/31/2015 11:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421530#msg1421530">Quote from: Rodal on 08/31/2015 09:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd

Yes, we all knew from the beginning that the best thing is to use a circular loop and that was the starting recommendation, but he doesn't know how to input a circular loop in Meep, only knows how to input straight dipole antennas.

So can any of the available antenna design software output an antenna into a format MEEP likes?  http://www.arrl.org/antenna-modeling (http://www.arrl.org/antenna-modeling)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/01/2015 12:39 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421557#msg1421557">Quote from: SteveD on 08/31/2015 11:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421530#msg1421530">Quote from: Rodal on 08/31/2015 09:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd

Yes, we all knew from the beginning that the best thing is to use a circular loop and that was the starting recommendation, but he doesn't know how to input a circular loop in Meep, only knows how to input straight dipole antennas.

So can any of the available antenna design software output an antenna into a format MEEP likes?  http://www.arrl.org/antenna-modeling (http://www.arrl.org/antenna-modeling)
It is not a problem of modellling the behavior of the antenna.

Once you input a straight dipole antenna into Meep, for example, Meep will do just as good or better a job at modelling the behavior of the antenna than any other software.

Instead it is a simple issue of inputting that current is flowing through a  circular wire antenna, just the issue of inputting the circular shape into Meep in 3D Cartesian coordinates.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/01/2015 01:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd

I'm not certain that it will work but I think its worth a try. I know this code:

(define stubsideleft (list
(make source (src (make gaussian-src (frequency fmeep) (fwidth BW) ))
             (component Ex)
             (center  (- 0 bxant) byant bzant)
             (size bantsizex bantsizey antsizez)
             (amplitude (exp (* 0+1i pi)))
             (axis axex axey axez) )
))


Specifically the line, (amplitude (exp (* 0+1i pi))), shifts the phase of the antenna RF by pi or 180 degrees. I also know I can write a software loop in Scheme. I also know where the center of each dipole or point source is so it seems that the phase of each source should depend on the phase of and distance from the previous source around the antenna loop. Thing I'm not certain about is if the time-stepping in meep will mess with the phasing. I'm working with the assumption that it will not as meep must surly maintain proper source phasing from one time-step to the next. Without doing so, meep couldn't propagate RF waves.

Now, if anyone wants to give me the math for transforming points on the antenna loop circumference to cartesian x, y, z, I would be pleased to check it against mine. Might well save me considerable time. Or maybe meep supplies such coordinate transformation functions that I just haven't needed to look into. (It just occurred to me to look.) And just exactly how much is the phase shift from one point to the next. The arc distance divided by the wavelength? Actually, I guess it would be negative of that as phase increases with time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/01/2015 02:05 AM
While I'm here posting, I did want to mention an idea stemming from Dr. Rodel's post about modelling copper losses as the surface integral of the square of the magnetic field at the surface. (Badly paraphrased, appopogies).

The idea is that if going to the length of actually modelling the boundary losses in this way, it would be rather simple to add a photon tunnelling model to the boundary losses. Meep could deal with that, too, assuming we could come up with an acceptable model for photon tunnelling compatible with Meep (MIT Electromagnetic Equation Propagation).

Oh, and the name kind of tells us why we can't easily simulate current in a wire. It is the Electromagnetic Equations that are propagated so to simulate a wire, it is "Write your own function" time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/01/2015 02:32 AM
Long shot here, but I was reading up on how squeezed light can be generated and I found that one way is via nonlinear frequency mixing. I think I saw evidence of frequency mixing a few months ago by accident. Guess I pretty much have to bust out the test equipment again now to confirm.

http://physics.stackexchange.com/questions/83/how-is-squeezed-light-produced
https://en.wikipedia.org/wiki/Nonlinear_optics#Nonlinear_optical_processes

Anyway, there's some literature out there about using squeezed vacuum for propulsion which is interesting.
http://www.researchgate.net/publication/258317790_Preliminary_Theorectical_Considerations_for_Getting_Thrust_via_Squeezed_Vacuum

http://www.researchgate.net/publication/234887561_Extraction_of_Thrust_from_Quantum_Vacuum_Using_Squeezed_Light
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/01/2015 02:52 AM
If firing a magnetron into a cavity generates squeezed vacuum, I'm going to start using an oven instead. I hear that squeezed food tastes terrible.
 :P
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/01/2015 02:54 AM
It is the copper oxides.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 09/01/2015 03:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421398#msg1421398">Quote from: SeeShells on 08/31/2015 02:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421328#msg1421328">Quote from: deltaMass on 08/31/2015 04:24 AM</a>
Indeed. But bear in mind that both the spring and the pivot counterbalance solution potentially introduce extra stiction.
I think rfmwguy is seeing stiction from someplace else other than the knife edge, maybe from  his liquid conductor? I would take it out of the loop (take out the copper wires) and see what amount of stiction he is then seeing.

Personal preference I went with a rolling knife edge and haven't even been able to measure any stiction and my scales are set to .01 gram.

The balance used in Ohaus scales consists of an agate plane on the bottom with a hardened steel knife edge resting on it.   Sometimes the agate will have a groove in it to hold the knife edge and keep it from wandering.   When there is a groove it is well polished since any scratches or pits will erode the steel.   Agate is a tough material and is harder than steel.    With a large balance arm the knife edge could be a replacement blade for a jointer and the agate plane could be a quartz flat.   No grease, oil or lubricant should be used on it since it will increase stiction.   Guards need to be installed to keep the beam from moving enough that the knife edge leaves the agate surface.  Quartz flats are usually round so as large a one as can be found would be needed.  They are also available in rectangular shapes.   It is an expensive way to go since I'm sure the quartz flat would not be useable as such afterwards.   Here is a link to a company that makes quartz flats,   http://www.customscientific.com/flats.htm

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 09/01/2015 07:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421599#msg1421599">Quote from: zen-in on 09/01/2015 03:26 AM</a>
   Agate is a tough material and is harder than steel.    With a large balance arm the knife edge could be a replacement blade for a jointer and the agate plane could be a quartz flat.

I am not sure but I heard that Iphone 6 use sapphire windows, in that case according to mohs scale it is a lot harder than quartz

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/01/2015 08:00 AM
Two ideas:

1- The use of composite waveguide at the output of the magnetron could help to reduce its thermal coupling to the frustrum.

2- If composite waveguide is not available, why not to introduce a 1  or 2 mm (or even more) insulating spacer or free air séparation between the waveguide flanges of both magnetron and frustrum still to limit their thermal coupling. There would be a small RF loss and VSWR degradation but  I think fully acceptable for the test.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/01/2015 12:48 PM

The word ``stiction'' was coined at IBM General Products Division labs in San Jose, CA around 1980 when they encountered that head slider getting stuck to the disk surface while resting at high humidities due to liquid mediated adhesion. High lateral force had to be applied to initiate sliding to overcome high static friction or sticking, hence leading to the term stiction.  This is not at all the contact issue of in the knife edge contact problem in RFMWGUY's experiment.  Rather, the problem is due to the well known issue of plastic deformation at the nano-scale roughness of contact, with the material nano-contact stresses exceeding the yield stress of the metals involved in contact.  It is not due to liquid mediated adhesion.  On the contrary, it is a dry contact problem.

Strictly speaking it is incorrect to use the term "stiction" to the contact of two knife edges as being used in RFMWGUY's experiment or to use the word stiction for the contact issues associated with a knife-edge balance.  The article on stiction in Wikipedia (like many articles in Wikipedia) lacks scholarship.

A couple of peer-reviewed articles (there are literally hundreds of articles, and dozens of books on Tribology showing this known fact) clarifying the benefits of lubrication in contact problems:

http://jbyoon0901.cafe24.com/wp-content/uploads/2013/05/APL_2011_An-insulating-liquid-environment-for-reducing-adhesion-in-a-microelectromechanicalsystem.pdf?ckattempt=1


http://masters.dgtu.donetsk.ua/2014/fimm/mitina/library/article11.pdf

----------
PS: Agate is not at all a tough material when compared to steel, and when using a scientific measure of toughness.  Agate is a crystalline variety of silica, found in nature, in volcanic rocks and certain metamorphic rocks, as such it is technically a ceramic material.  It lacks the toughness ductility like steel, agate has a lower Fracture Toughness (measured as G1c) than steel.  As to "hardness", hardness is not a scientific measure, there are different ways to measure "hardness" as they mix different scientific measures together like the yield strength, and stiffness together. In the Mohs Hardness Scale Agate can have a hardness of 6 to 7 Mohs, while steels can have a Mohs hardness from 5 to 8.5.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 09/01/2015 01:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421674#msg1421674">Quote from: Rodal on 09/01/2015 12:48 PM</a>
In the Mohs Hardness Scale Agate can have a hardness of 6 to 7 Mohs, while steels can have a Mohs hardness from 5 to 8.5.

An easy way to guess if there is a good contact is to use a hardness test with a penetrator shaped in the same way as the one of the scale.
If for example a pin is used on a flat plate a good approximation would be to use a pyramid penetrator.

For example quartz Vickers hardness give us 480 to 1100 and Corundum 2000 to 2700. (Steel will not be higher than 1000)
After this we could use Hertz pressure with a conical penetrator to guess the deformation.
https://en.wikipedia.org/wiki/Contact_mechanics

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/01/2015 02:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421674#msg1421674">Quote from: Rodal on 09/01/2015 12:48 PM</a>
The word ``stiction'' was coined at IBM General Products Division labs in San Jose, CA around 1980 when they encountered that head slider getting stuck to the disk surface while resting at high humidities due to liquid mediated adhesion. High lateral force had to be applied to initiate sliding to overcome high static friction or sticking, hence leading to the term stiction.  This is not at all the contact issue of in the knife edge contact problem in RFMWGUY's experiment.  Rather, the problem is due to the well known issue of plastic deformation at the nano-scale roughness of contact, with the material nano-contact stresses exceeding the yield stress of the metals involved in contact.  It is not due to liquid mediated adhesion.  On the contrary, it is a dry contact problem.

Strictly speaking it is incorrect to use the term "stiction" to the contact of two knife edges as being used in RFMWGUY's experiment or to use the word stiction for the contact issues associated with a knife-edge balance.  The article on stiction in Wikipedia (like many articles in Wikipedia) lacks scholarship.

A couple of peer-reviewed articles (there are literally hundreds of articles, and dozens of books on Tribology showing this known fact) clarifying the benefits of lubrication in contact problems:

http://jbyoon0901.cafe24.com/wp-content/uploads/2013/05/APL_2011_An-insulating-liquid-environment-for-reducing-adhesion-in-a-microelectromechanicalsystem.pdf?ckattempt=1


http://masters.dgtu.donetsk.ua/2014/fimm/mitina/library/article11.pdf

----------
PS: Agate is not at all a tough material when compared to steel, and when using a scientific measure of toughness.  Agate is a crystalline variety of silica, found in nature, in volcanic rocks and certain metamorphic rocks, as such it is technically a ceramic material.  It lacks the toughness ductility like steel, agate has a lower Fracture Toughness (measured as G1c) than steel.  As to "hardness", hardness is not a scientific measure, there are different ways to measure "hardness" as they mix different scientific measures together like the yield strength, and stiffness together. In the Mohs Hardness Scale Agate can have a hardness of 6 to 7 Mohs, while steels can have a Mohs hardness from 5 to 8.5.
Wow! was that a flash back!

Well done Dr. Rodel. Was with a company that won 5 Editor Choice Awards for PCs in the 80's. We were very aware of the issues of stiction in hard drives. Especially when parked during a platter spin down and the RR head would "park". Our suggestion to IBM was upon spinning up again that they "bump" the RR head right at spin up to overcome the two surfaces stickion. It seemed to work and only involved a change of the devices program in its eeprom.

I'm looking for the the best rolling surface. It may not be a point like in a watch's jeweled movement, but I needed to distributing the heavy contact weight of the frustum and counter balance. That's why I did the the ^ angle with a hardened steel angle iron. It provides a curved contact with a light graphite filling (simple pencil lead) on the microscopic imperfections on the radius. Rolling over surface are 2 side by side graphite composite tubes. Even at .01g I can detect no surface contact generated resistance to movement. I'm not sure what the coefficient of friction is but, it is below what I can detect.

The problem with 2 knife edges which are heat treated. Heat treating forms crystalline structures in the steel on the edge. While they are hard they are also brittle and will tend to fracture along the crystalline boundaries. That tendency to fracture at the contact points is the reason for this patent.
http://www.google.com/patents/US3413044
If I was going to be able to detect any friction in the setup I would have gone to this pivot system. I still may,  I don't want to see any lateral movement in the beam while oscillating.

Shell 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/01/2015 02:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421688#msg1421688">Quote from: SeeShells on 09/01/2015 02:07 PM</a>
...Wow! was that a flash back!...
It's fascinating how the lives of different people in this thread are intertwined in disparate fields, and we are all here discussing experiments and analysis of a seemingly impossible space propulsion  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 09/01/2015 02:37 PM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421629#msg1421629">Quote from: OttO on 09/01/2015 07:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421599#msg1421599">Quote from: zen-in on 09/01/2015 03:26 AM</a>
   Agate is a tough material and is harder than steel.    With a large balance arm the knife edge could be a replacement blade for a jointer and the agate plane could be a quartz flat.

I am not sure but I heard that Iphone 6 use sapphire windows, in that case according to mohs scale it is a lot harder than quartz

The iPhone 6 doesn't use such a screen.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/01/2015 03:16 PM
Folks - sorry to go AWOL after volunteering to do something, but my father has been visiting for some days. He's 81 - he doesn't need much looking after, but he does spend his days wandering through my house and garden pointing out chores which need doing, and organizing me to do them straight away...

I said I would do fourier analysis on the beam movements of rfmwguy's first experiment if someone would post the time-series, which was very soon done.

Of course, I omitted to mention that I would need the magnetron on/off audio signal to make much progress. With that I can match up the magnetron signal to the filtered beam signal and see what it tells us.

The rough analysis so far doesn't say much beyond what can be seen by eye in the plots posted,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 09/01/2015 03:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421697#msg1421697">Quote from: Star One on 09/01/2015 02:37 PM</a>

The iPhone 6 doesn't use such a screen.

Are you sure? I search a bit and found this:
Sapphire windows are used in Apple Touch ID of the iPhone 5s, iPhone 6, and iPad mini 3and the display of the Apple Watch. Also, sapphire covers are used for the rear camera in every iPhone 5 or newer.
https://en.wikipedia.org/wiki/Sapphire

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/01/2015 04:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421708#msg1421708">Quote from: OttO on 09/01/2015 03:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421697#msg1421697">Quote from: Star One on 09/01/2015 02:37 PM</a>

The iPhone 6 doesn't use such a screen.

Are you sure? I search a bit and found this:
Sapphire windows are used in Apple Touch ID of the iPhone 5s, iPhone 6, and iPad mini 3and the display of the Apple Watch. Also, sapphire covers are used for the rear camera in every iPhone 5 or newer.
https://en.wikipedia.org/wiki/Sapphire
http://www.dailymail.co.uk/sciencetech/article-2758097/How-Apple-s-iPhone-6-ion-strengthened-screen-Expert-reveals-chemical-process-used-create-display.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: birchoff on 09/01/2015 04:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421583#msg1421583">Quote from: Mulletron on 09/01/2015 02:32 AM</a>
Long shot here, but I was reading up on how squeezed light can be generated and I found that one way is via nonlinear frequency mixing. I think I saw evidence of frequency mixing a few months ago by accident. Guess I pretty much have to bust out the test equipment again now to confirm.

http://physics.stackexchange.com/questions/83/how-is-squeezed-light-produced
https://en.wikipedia.org/wiki/Nonlinear_optics#Nonlinear_optical_processes

Anyway, there's some literature out there about using squeezed vacuum for propulsion which is interesting.
http://www.researchgate.net/publication/258317790_Preliminary_Theorectical_Considerations_for_Getting_Thrust_via_Squeezed_Vacuum

http://www.researchgate.net/publication/234887561_Extraction_of_Thrust_from_Quantum_Vacuum_Using_Squeezed_Light

I find this rather interesting since I just found the following on my facebook feed claiming proof that squeezed light is real.

http://www.cam.ac.uk/research/news/scientists-squeeze-light-one-particle-at-a-time

That said if this is going to be an avenue used to prove thrust from the EmDrive then alot of work would need to go into to explaining how the frustum is squeezing light at what seems to be lower power levels and in a radically different environment.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/01/2015 04:10 PM
NSF-1701 New Video - Static test of assembly today without electrodes in galinstan, which adds dampening and drag. When the galinstan was removed, there were wild movements of laser spot, as I noted when I first designed the test stand. Therefore I re-attached Doc's oil dampener, which greatly reduced vertical meanderings. The oil dampener addition and galinstan removal provided a laser spot displacement on the target of approximately the same amount. IOW, galinstan and no oil dampener and 500 mg weight added approximately equal no galinstan and oil dampener and 200 mg weight added. So, the drag/viscosity of galinstan is equal to about 300 mg...far more than I imagined.

Here's the video for detailed analysis:

https://youtu.be/jvjrJK90iYM
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/01/2015 04:11 PM

Found this article in the opinion pages of the New York edition. (Times)  This may not be a good scientific source but the author nails it IMO.

Quote
But the failure to replicate is not a cause for alarm; in fact, it is a normal part of how science works.

Suppose you have two well-designed, carefully run studies, A and B, that investigate the same phenomenon. They perform what appear to be identical experiments, and yet they reach opposite conclusions. Study A produces the predicted phenomenon, whereas Study B does not. We have a failure to replicate.

Does this mean that the phenomenon in question is necessarily illusory? Absolutely not. If the studies were well designed and executed, it is more likely that the phenomenon from Study A is true only under certain conditions. The scientist’s job now is to figure out what those conditions are, in order to form new and better hypotheses to test.

http://www.nytimes.com/2015/09/01/opinion/psychology-is-not-in-crisis.html?partner=EXCITE&ei=5043&_r=0 (http://www.nytimes.com/2015/09/01/opinion/psychology-is-not-in-crisis.html?partner=EXCITE&ei=5043&_r=0)

Moderator: If this violates copyrights please remove the post.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/01/2015 04:21 PM
This Gordian knot is cut by running a truly stand-alone system on self-contained battery power. Especially considering the tiny forces purported to be involved. Even with stand-alone operation, there are six thermal effects to be dealt with and stiction too. But if you insist:

1. What is the maximum current flowing through the Galinstan wires? If the wires can be made thinner, that would go partway to reducing surface tension.

2. The best place for the Galinstan is right by the pivot. That minimises the lever arm of spurious torques.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/01/2015 04:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421717#msg1421717">Quote from: rfmwguy on 09/01/2015 04:10 PM</a>
NSF-1701 New Video - Static test of assembly today without electrodes in galinstan, which adds dampening and drag. When the galinstan was removed, there were wild movements of laser spot, as I noted when I first designed the test stand. Therefore I re-attached Doc's oil dampener, which greatly reduced vertical meanderings. The oil dampener addition and galinstan removal provided a laser spot displacement on the target of approximately the same amount. IOW, galinstan and no oil dampener and 500 mg weight added approximately equal no galinstan and oil dampener and 200 mg weight added. So, the drag/viscosity of galinstan is equal to about 300 mg...far more than I imagined.

Here's the video for detailed analysis:

https://youtu.be/jvjrJK90iYM

Excellent.  By the way, let's not forget that you also verified the importance of air currents in the motion of the beam, upon removal of the Galistan damping action.  There are still posters that question whether air currents are responsible for such motions.  As I understand it, you tested by adding 500 mg weight, hence there is no electromagnetic force involved in this test.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/01/2015 04:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421722#msg1421722">Quote from: Rodal on 09/01/2015 04:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421717#msg1421717">Quote from: rfmwguy on 09/01/2015 04:10 PM</a>
NSF-1701 New Video - Static test of assembly today without electrodes in galinstan, which adds dampening and drag. When the galinstan was removed, there were wild movements of laser spot, as I noted when I first designed the test stand. Therefore I re-attached Doc's oil dampener, which greatly reduced vertical meanderings. The oil dampener addition and galinstan removal provided a laser spot displacement on the target of approximately the same amount. IOW, galinstan and no oil dampener and 500 mg weight added approximately equal no galinstan and oil dampener and 200 mg weight added. So, the drag/viscosity of galinstan is equal to about 300 mg...far more than I imagined.

Here's the video for detailed analysis:

https://youtu.be/jvjrJK90iYM

Excellent.  By the way, let's not forget that you also verified the importance of air currents in the motion of the beam, upon removal of the Galistan damping action.  There are still posters that question whether air currents are responsible for such motions.  As I understand it, you tested by adding 500 mg weight, hence there is no electromagnetic force involved in this test.
Doc, this test was 0, 200, 0 and 100 mg. No power applied.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 09/01/2015 05:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421717#msg1421717">Quote from: rfmwguy on 09/01/2015 04:10 PM</a>
NSF-1701 New Video - Static test of assembly today without electrodes in galinstan, which adds dampening and drag. When the galinstan was removed, there were wild movements of laser spot, as I noted when I first designed the test stand. Therefore I re-attached Doc's oil dampener, which greatly reduced vertical meanderings. The oil dampener addition and galinstan removal provided a laser spot displacement on the target of approximately the same amount. IOW, galinstan and no oil dampener and 500 mg weight added approximately equal no galinstan and oil dampener and 200 mg weight added. So, the drag/viscosity of galinstan is equal to about 300 mg...far more than I imagined.

Here's the video for detailed analysis:

https://youtu.be/jvjrJK90iYM

I counted the grid lines based on what I though was the center of the laser spot, using the starting place as 0.

0        starting with no added weight
+20    with 200 mg added
+23    with 200 mg after it drifted up
-2       with 200 mg removed
+8.5   with 100 mg added (couldn't decide which grid line, so I'm going with +8.5)

The initial adding of 200 mg resulted in the spot moving up 20 grid lines (about 10 mg per line). When the weight was removed the balance didn't quite make it back to its initial center, but only was off by 2 grid lines. When the 100 mg was added the spot moved up 10.5 grid lines (still about 10 mg per line).

My conclusion is that any movement with the oil damper and no galistan is equal to approximately 10 mg per grid line. Waiting around could result in some drift, but the balance settles quickly, so measurements should be done as soon as the oscillation stops.

As deltaMass suggeseted, the best place for the galistan is at the pivot.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: birchoff on 09/01/2015 05:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421716#msg1421716">Quote from: birchoff on 09/01/2015 04:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421583#msg1421583">Quote from: Mulletron on 09/01/2015 02:32 AM</a>
Long shot here, but I was reading up on how squeezed light can be generated and I found that one way is via nonlinear frequency mixing. I think I saw evidence of frequency mixing a few months ago by accident. Guess I pretty much have to bust out the test equipment again now to confirm.

http://physics.stackexchange.com/questions/83/how-is-squeezed-light-produced
https://en.wikipedia.org/wiki/Nonlinear_optics#Nonlinear_optical_processes

Anyway, there's some literature out there about using squeezed vacuum for propulsion which is interesting.
http://www.researchgate.net/publication/258317790_Preliminary_Theorectical_Considerations_for_Getting_Thrust_via_Squeezed_Vacuum

http://www.researchgate.net/publication/234887561_Extraction_of_Thrust_from_Quantum_Vacuum_Using_Squeezed_Light

I find this rather interesting since I just found the following on my facebook feed claiming proof that squeezed light is real.

http://www.cam.ac.uk/research/news/scientists-squeeze-light-one-particle-at-a-time

That said if this is going to be an avenue used to prove thrust from the EmDrive then alot of work would need to go into to explaining how the frustum is squeezing light at what seems to be lower power levels and in a radically different environment.

Also if squeezed light is a proven thing wouldnt this be a smoking gun for those in the ZPF community that believe that the vaccum is not immutable in the strictest sense of the word. Which would seem to open the door for Dr. White's theory even more.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 09/01/2015 05:11 PM


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421708#msg1421708">Quote from: OttO on 09/01/2015 03:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421697#msg1421697">Quote from: Star One on 09/01/2015 02:37 PM</a>

The iPhone 6 doesn't use such a screen.

Are you sure? I search a bit and found this:
Sapphire windows are used in Apple Touch ID of the iPhone 5s, iPhone 6, and iPad mini 3and the display of the Apple Watch. Also, sapphire covers are used for the rear camera in every iPhone 5 or newer.
https://en.wikipedia.org/wiki/Sapphire

Yes I own one. The camera part is correct but not the front screen. There was rumours they were going to do this but it didn't come to pass. I can't speak for the watch screen.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/01/2015 05:27 PM

Honestly the 100kW magnetron is cheap, cheap cheap. What IS expensive is the waveguide launcher, water cooler, transformer, safety relay, etc. For instance attached is the datasheet on the Sairem 100kW 915MHz microwave generator, perfect for EM-Drive/Q-Thuster testing... but costs $133,000 Euros of which the magnetron is $10,000. Thankfully a company is working with us on a similar (better?) set up depending on their HFSS modelling. The good news about the wavefront generator is I don't see why for testing purposes you need to have the magnetron right there beside the frustrum and it seems easy to test different ports.

Now cooling is a problem also on the frustrum because you've only got like 1-2m2 surface area but have to do 100kW cooling with a 5K differential. I'm tempted to do 50kW and put the frustrum in a giant water bath with -40degC water coming in for a 5 minute test run (you have to go immersion cooling, forced cooling and your limited to like 10kW). The next step after that cost wise is all out liquid nitrogen.. I am looking at renting a system from a vendor that owes me a favor. Once you go that route I suppose you should aim for cyrogenic freezing as it should help Q factor (closer to superconductor the better right?).

There is also a catch-22, you want a custom mass produced RF generator at L-band frequency or above, but right now there is little to no market for that.... though if Q-thruster/EM-Drive work you have a massive market but don't really have any conclusive data to justify the expense.

That's why I think this is the way to go - an experiment above background.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421504#msg1421504">Quote from: flux_capacitor on 08/31/2015 07:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421491#msg1421491">Quote from: Rodal on 08/31/2015 06:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421489#msg1421489">Quote from: Rodal on 08/31/2015 06:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421485#msg1421485">Quote from: rfmwguy on 08/31/2015 06:25 PM</a>
Do have a dumb question regarding thermal lift. Even if the magnetron is removed from the frustum assembly, it will generate heat around it's  tube, thereby creating lift. If it is mechanically attached to the frustum, wouldn't the lift be simply recentered?

There will be less conductive heating of the frustum, depending on how far away and the interconnects used, but the maggy itself will remain hot, regardless...

Yes, that's essentially correct.  The magnetron is what gets hottest.  As long as the magnetron is mechanically attached to the fustrum, the lift created by the natural thermal convection currents from the magnetron will carry the frustum with it, so having the magnetron attached to a waveguide doesn't seem to improve things since it makes everything heavier (bad) and there is no improvement because the magnetron is still mechanically attached.

A possible improvement is to provide more and better heat sink to the magnetron. 

Pure aluminum has a conductivity of 230 W/m-K. Copper is better: 390 W/m-K which means a 70% increase in conduction over aluminum. That’s the good news. The down side of copper is that it weighs three times more than aluminum, costs the same on a per pound basis and is more difficult to machine. Due to limited high temperature formability, a copper extrusion will not yield the same detail as aluminum. Also, machining copper takes more time and wears cutters at a much higher rate. However, when an application is limited in conduction, copper is a commonly used alternative.

Forced convection from a fan is out of consideration as it would interfere with the measurement.  Liquid cooling is difficult to implement.

This magnetron for example, requires water cooling:

http://www.ok1rr.com/tubes/burle/s94608e.pdf

Liquid Cooling:
Tube anode requires liquid cooling Liquid flow must start
before application of filament voltage and, preferably,
continue for several minutes after removing voltage.
Interlock filament power supply with liquid flow to prevent
tube damage due to inadequate liquid flow. When liquid is
water, use of distilled or filtered deionized water is
essential.
Water Flow .... (15 kW anode dissipation) 20.4 I/min. (5.5 gpm)

It is a 0.95GHz magnetron though (instead of 2.45GHz)

A 0.915 GHz magnetron would have some benefits: the frustum would be slightly bigger to built, but the tolerance to achieve and maintain resonance would be easier than on a smaller frustum.

But at such a cost (how much?) for very high power, say a hundred to thousands of kilowatts, I wonder why those labs (like CraigPichach's university (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420716#msg1420716)) do not plan to use a much cleaner source of microwaves instead, like a klystron, which offers both high power and narrow band.

Magnetrons are ok because they are compact and that the 2.45 GHz models from ovens are really cheap. But with enough $$$ and other frequencies investigated, I think TWTAs and klystrons would do a better job.

EDIT: Whatever I'd love to see an experiment with an N2-cooled frustum powered by a 100kW-class liquid-cooled magnetron! This would be waaaay beyond what we saw even from Shawyer. :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/01/2015 05:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421575#msg1421575">Quote from: aero on 09/01/2015 01:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421521#msg1421521">Quote from: WarpTech on 08/31/2015 09:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421483#msg1421483">Quote from: aero on 08/31/2015 06:20 PM</a>
My intention is to simulate a real loop using phase matched dipoles or point sources, ignoring the mechanics of implementation. I think that is best because Shell can then approximate the real loop to the best of her ability. Hopefully the simulation and implementation will converge toward the same end result. But I need to go off and do that now.
aero

I don't see how multiple dipoles arranged in a circle simulates a loop, unless you're trying to implement a very high harmonic in the azimuthal direction. For TE012, there are only 2 poles around the circle.

Why is it difficult to simulate current through a piece of wire, fed by a current source?
Todd

I'm not certain that it will work but I think its worth a try. I know this code:

(define stubsideleft (list
(make source (src (make gaussian-src (frequency fmeep) (fwidth BW) ))
             (component Ex)
             (center  (- 0 bxant) byant bzant)
             (size bantsizex bantsizey antsizez)
             (amplitude (exp (* 0+1i pi)))
             (axis axex axey axez) )
))


Specifically the line, (amplitude (exp (* 0+1i pi))), shifts the phase of the antenna RF by pi or 180 degrees. I also know I can write a software loop in Scheme. I also know where the center of each dipole or point source is so it seems that the phase of each source should depend on the phase of and distance from the previous source around the antenna loop. Thing I'm not certain about is if the time-stepping in meep will mess with the phasing. I'm working with the assumption that it will not as meep must surly maintain proper source phasing from one time-step to the next. Without doing so, meep couldn't propagate RF waves.

Now, if anyone wants to give me the math for transforming points on the antenna loop circumference to cartesian x, y, z, I would be pleased to check it against mine. Might well save me considerable time. Or maybe meep supplies such coordinate transformation functions that I just haven't needed to look into. (It just occurred to me to look.) And just exactly how much is the phase shift from one point to the next. The arc distance divided by the wavelength? Actually, I guess it would be negative of that as phase increases with time.

I have found a nice calculator for that coordinate conversion :)
http://www.calc3d.com/gjavascriptcoordcalc.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 09/01/2015 05:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421708#msg1421708">Quote from: OttO on 09/01/2015 03:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421697#msg1421697">Quote from: Star One on 09/01/2015 02:37 PM</a>

The iPhone 6 doesn't use such a screen.

Are you sure? I search a bit and found this:
Sapphire windows are used in Apple Touch ID of the iPhone 5s, iPhone 6, and iPad mini 3and the display of the Apple Watch. Also, sapphire covers are used for the rear camera in every iPhone 5 or newer.
https://en.wikipedia.org/wiki/Sapphire

There are steel alloys that are harder than quartz but any knife edge would not be that hard.   Sapphire of course is much harder and so on that basis would be better.   However the sapphire flat would have to have enough mass to support the weight of the beam without bending and so would be rather pricey.   Watch crystals have been made from sapphire for a long time.   One way to identify sapphire is to touch it to the back of your hand.  If it feels cool it is sapphire.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 09/01/2015 06:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421575#msg1421575">Quote from: aero on 09/01/2015 01:35 AM</a>
I'm not certain that it will work but I think its worth a try. I know this code:

(define stubsideleft (list
(make source (src (make gaussian-src (frequency fmeep) (fwidth BW) ))
             (component Ex)
             (center  (- 0 bxant) byant bzant)
             (size bantsizex bantsizey antsizez)
             (amplitude (exp (* 0+1i pi)))
             (axis axex axey axez) )
))


Specifically the line, (amplitude (exp (* 0+1i pi))), shifts the phase of the antenna RF by pi or 180 degrees. I also know I can write a software loop in Scheme. I also know where the center of each dipole or point source is so it seems that the phase of each source should depend on the phase of and distance from the previous source around the antenna loop. Thing I'm not certain about is if the time-stepping in meep will mess with the phasing. I'm working with the assumption that it will not as meep must surly maintain proper source phasing from one time-step to the next. Without doing so, meep couldn't propagate RF waves.

Now, if anyone wants to give me the math for transforming points on the antenna loop circumference to cartesian x, y, z, I would be pleased to check it against mine. Might well save me considerable time. Or maybe meep supplies such coordinate transformation functions that I just haven't needed to look into. (It just occurred to me to look.) And just exactly how much is the phase shift from one point to the next. The arc distance divided by the wavelength? Actually, I guess it would be negative of that as phase increases with time.

in pseudo code:


divisions = 10
radius = 1
angle = 2*pi/divisions

for (n =0; n< divisions; n++)
    a = angle*n
    x = cos(a)*radius
    y = sin(a)*radius
    amplitude = exp((0+1i)*a)
    make_new_source(x, y, amplitude)


Angles in radians.  Amplitude is based on "(amplitude (exp (* 0+1i pi)))" - when the source is 180 degrees from the first source, the amplitude is exp((0+1i)*pi).

Is that what you were looking for?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/01/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421738#msg1421738">Quote from: CraigPichach on 09/01/2015 05:27 PM</a>
That's why I think this is the way to go - an experiment above background.
More power is not necessarily a panacea. It may be that thermal artifacts scale as fast, or faster than does any signal.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/01/2015 06:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421749#msg1421749">Quote from: lmbfan on 09/01/2015 06:09 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421575#msg1421575">Quote from: aero on 09/01/2015 01:35 AM</a>
I'm not certain that it will work but I think its worth a try. I know this code:

(define stubsideleft (list
(make source (src (make gaussian-src (frequency fmeep) (fwidth BW) ))
             (component Ex)
             (center  (- 0 bxant) byant bzant)
             (size bantsizex bantsizey antsizez)
             (amplitude (exp (* 0+1i pi)))
             (axis axex axey axez) )
))


Specifically the line, (amplitude (exp (* 0+1i pi))), shifts the phase of the antenna RF by pi or 180 degrees. I also know I can write a software loop in Scheme. I also know where the center of each dipole or point source is so it seems that the phase of each source should depend on the phase of and distance from the previous source around the antenna loop. Thing I'm not certain about is if the time-stepping in meep will mess with the phasing. I'm working with the assumption that it will not as meep must surly maintain proper source phasing from one time-step to the next. Without doing so, meep couldn't propagate RF waves.

Now, if anyone wants to give me the math for transforming points on the antenna loop circumference to cartesian x, y, z, I would be pleased to check it against mine. Might well save me considerable time. Or maybe meep supplies such coordinate transformation functions that I just haven't needed to look into. (It just occurred to me to look.) And just exactly how much is the phase shift from one point to the next. The arc distance divided by the wavelength? Actually, I guess it would be negative of that as phase increases with time.

in pseudo code:


divisions = 10
radius = 1
angle = 2*pi/divisions

for (n =0; n< divisions; n++)
    a = angle*n
    x = cos(a)*radius
    y = sin(a)*radius
    amplitude = exp((0+1i)*a)
    make_new_source(x, y, amplitude)


Angles in radians.  Amplitude is based on "(amplitude (exp (* 0+1i pi)))" - when the source is 180 degrees from the first source, the amplitude is exp((0+1i)*pi).

Is that what you were looking for?

Sort of, except for one additional detail that I learned about which is:
Quote
Specify the direction and type of the current component: e.g. Ex, Ey, etcetera for an electric-charge current, and Hx, Hy, etcetera for a magnetic-charge current. Note that currents pointing in an arbitrary direction are specified simply as multiple current sources with the appropriate amplitudes for each component. No default.
The boldfaced (added) sentence is the detail.
So in order to make the current flow around the loop and stay in phase, I need 3 source statements for each dipole, one each for dx, dy and dz, appropriately weighted so that the total amplitude is 1, and the phase relationship is retained. I have this -

(set! mag (sqrt (+ (* dx dx) (* dy dy) (* dz dz))))
    (set! emmagx (* mag dx))
    (set! emmagy (* mag dy))                  ; check this, really want emmag normalized to 1
    (set! emmagz (* mag dz))


and three of these -

(make source (src (make continuous-src (frequency mple_f))); (fwidth df)))
        (component Hz)
        (center rx ry rz)
        (size dx dy dz)
        (amplitude (exp (* 0+1i pfase)))
        (axis 0 0 1) ) 


So now I need to properly include the emmag into the amplitude without messing up the phasing. In other words, I think it is a real term multiplication of a complex number. Leaning toward
(amplitude (* emmag (exp (* 0+1i pfase))))
but of course that won't work because of the real 0 in the complex frequency. All it will do is mess with the phase.

So I'm a little bit stuck but have only been considering it today. Maybe I'll think of something but guidance is appreciated. And thanks lmbfan, for the above - input really helps.

::Hmm - maybe it will work since emmag is multiplying exp, and not the complex number.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/01/2015 07:16 PM

If we see >0.1N firing into the ground; it would be a lot easier to show no thermal artifact or measurement error would explain that and you've opened the door for some real cash on custom experiments.

At 0.0003N/kW trying to see 0.000003N with these 100W tests in a manner that thermal effects aren't in play... your going to spend the money on the magnetron/cooling system on the laser required to see that tiny micro-newton force and mitigate all other sources. Even at 0.01N/kW (Shawyer) your looking for 0.001N - thermal effects due to the microwave heat can be orders of magnitude greater than that. I'd argue that it's more valuable to have one good high powered experiment using existing equipment than what could potentially be hundreds of inconclusive experiments.

Believe Yang and Fetta and at 100kW you'll see 100N into the ground.... that I would love to see. I think we'd all agree that this phenomena was real then. Sure seems unlikely, but that is definitely worth a shot just to witness that.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421750#msg1421750">Quote from: deltaMass on 09/01/2015 06:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421738#msg1421738">Quote from: CraigPichach on 09/01/2015 05:27 PM</a>
That's why I think this is the way to go - an experiment above background.
More power is not necessarily a panacea. It may be that thermal artifacts scale as fast, or faster than does any signal.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/01/2015 07:52 PM
The assumption that thermal effects are unidirectional isn't necessarily so. Take, for example, shifts in the centre of gravity when using a balance. Or gas jets which have an upwards component.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 09/01/2015 07:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421765#msg1421765">Quote from: aero on 09/01/2015 06:45 PM</a>
(set! mag (sqrt (+ (* dx dx) (* dy dy) (* dz dz))))
    (set! emmagx (* mag dx))
    (set! emmagy (* mag dy))                  ; check this, really want emmag normalized to 1
    (set! emmagz (* mag dz))



I think you want to divide, not multiply, e.g. " (set! emmagx (/ dx mag)) ".  If you do that, sqrt(emmagx^2 + emmagy^2 + emmagz^2) = 1.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421765#msg1421765">Quote from: aero on 09/01/2015 06:45 PM</a>
(make source (src (make continuous-src (frequency mple_f))); (fwidth df)))
        (component Hz)
        (center rx ry rz)
        (size dx dy dz)
        (amplitude (exp (* 0+1i pfase)))
        (axis 0 0 1) ) 


So now I need to properly include the emmag into the amplitude without messing up the phasing. In other words, I think it is a real term multiplication of a complex number. Leaning toward
(amplitude (* emmag (exp (* 0+1i pfase))))
but of course that won't work because of the real 0 in the complex frequency. All it will do is mess with the phase.

I don't know what you're getting at here.  If "emmag" is the magnitude and it's normalized to 1, what's the point of multiplying it with anything?

I feel like I'm missing something.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/01/2015 08:05 PM

My preference for the continuous unit is a scale; no centre of gravity issues and if there are photons or jets or some other logical explanation for a force shooting out the top of the unit we will literally see it. Granted this will only work with high power.

A funny safety question asked is what happens if the force direction is wrong and it shoots up... that got some chuckles on the teleconference.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421785#msg1421785">Quote from: deltaMass on 09/01/2015 07:52 PM</a>
The assumption that thermal effects are unidirectional isn't necessarily so. Take, for example, shifts in the centre of gravity when using a balance. Or gas jets which have an upwards component.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/01/2015 08:22 PM
Yes, we do tend to fantasise about the mythical hole in the ceiling
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/01/2015 08:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421788#msg1421788">Quote from: lmbfan on 09/01/2015 07:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421765#msg1421765">Quote from: aero on 09/01/2015 06:45 PM</a>
(set! mag (sqrt (+ (* dx dx) (* dy dy) (* dz dz))))
    (set! emmagx (* mag dx))
    (set! emmagy (* mag dy))                  ; check this, really want emmag normalized to 1
    (set! emmagz (* mag dz))



I think you want to divide, not multiply, e.g. " (set! emmagx (/ dx mag)) ".  If you do that, sqrt(emmagx^2 + emmagy^2 + emmagz^2) = 1.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421765#msg1421765">Quote from: aero on 09/01/2015 06:45 PM</a>
(make source (src (make continuous-src (frequency mple_f))); (fwidth df)))
        (component Hz)
        (center rx ry rz)
        (size dx dy dz)
        (amplitude (exp (* 0+1i pfase)))
        (axis 0 0 1) ) 


So now I need to properly include the emmag into the amplitude without messing up the phasing. In other words, I think it is a real term multiplication of a complex number. Leaning toward
(amplitude (* emmag (exp (* 0+1i pfase))))
but of course that won't work because of the real 0 in the complex frequency. All it will do is mess with the phase.

I don't know what you're getting at here.  If "emmag" is the magnitude and it's normalized to 1, what's the point of multiplying it with anything?

I feel like I'm missing something.

I want to use the same total amplitude that would be used with only one source, ie. 1. But now I have 3 sources weighed by the direction of the current = direction of the dipole and I still want the total amplitude to equal 1. That's what I mean and I think you answered that part, I need to divide.

But the significant part is here
Quote
Specify the direction and type of the current component: e.g. Ex, Ey, etcetera for an electric-charge current, and Hx, Hy, etcetera for a magnetic-charge current. Note that currents pointing in an arbitrary direction are specified simply as multiple current sources with the appropriate amplitudes for each component.
Does that mean I actually need to use (for electric-charge current) Ex, Ey and Ez components for the dx, dy and dz component directions of the dipole? That doesn't seem right. Or do I need to use 9 weighted sources, 3 each for Ex, Ey, and Ez. Or are those two choices really the same thing?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 09/01/2015 09:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421791#msg1421791">Quote from: deltaMass on 09/01/2015 08:22 PM</a>
Yes, we do tend to fantasise about the mythical hole in the ceiling

Yep. Since H. G. Wells' "The First Men in the Moon" invented the trope and E. E. Smith refined it in the "Skylark of Space", this is a portentous event many have been expecting one day to see.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/01/2015 09:23 PM
We've been working on simulating a frustum with a waveguide delivery and aperture coupling similar to the system developed by NWPU. It looks like we are exciting a TE011 in this system. As soon as we get access to a cluster we will be able to optimize the system to find a better s11.

Is anyone else having any luck with EM Pro? We have not been able to introduce a monopole antenna and use FDTD yet, this video is using a plane wave excitation at WG port 1. 

https://www.youtube.com/watch?v=p20wX-JnBI4&feature=youtu.be


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/01/2015 09:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421750#msg1421750">Quote from: deltaMass on 09/01/2015 06:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421738#msg1421738">Quote from: CraigPichach on 09/01/2015 05:27 PM</a>
That's why I think this is the way to go - an experiment above background.
More power is not necessarily a panacea. It may be that thermal artifacts scale as fast, or faster than does any signal.
I am beginning to understand how we must plan for thermal errors. Elsewhere, it was posted that the south african experiment measured upwards thrust. I find this a questionable test method as I've seen the results of thermal lift personally. Will continue to focus on downward movement only. Think I will set up a test for establishing max thermal lift point and then look for downward movement from there. As I continue tweaking the setup, I am becoming more critical...guess that's the way its supposed to be.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/01/2015 11:33 PM
Nice slideshow to get the gears turning.

It is nice to see there is considerable attention given to field propulsion techniques, but I don't get why EmDrive catches so much flack. EmDrive is a proposed method of field propulsion.

http://npo-astro.org/papers/Minami/Field%20Propulsion%20Systems%20for%20Space%20Travel%20%28H.pdf
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/01/2015 11:43 PM
Ironically if you see thrust in the down direction or even a null result at low power your actual thrust is probably greater as you are overcoming thermal buoyancy. At high power this becomes less complicated.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/01/2015 11:54 PM
Iulian Berca reported downward thrust when he flipped the device.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 09/02/2015 12:03 AM
Suggestion for today:
Best practice for pivots and beams. 
If our objective is to develop a DIY technique which allows us to have high precision
The modern analytical beam may provide us some useful “design features” that we can copy over to simpler designs. With some associated loss of precision
These modern analytical beams are capable of measuring down with confidence amounts being transferred to a precision of one tenth of a milligram or one ten-thousandth of a gram, ±0.0001 g. but are limited to 160-200 gram capacity ranges.
This a schematic of a well-known brand

Some features I could see being of help for DIY’s are
1. Truss type design to keep weight low and rigidly high
2. Precision certified weights
3. Fixed Not pivoted counterweights
4. Using Zero weights around centre of pivot axis
8. Knife edge balance
12. Light source going through glass graduation plate [note the small distance required say 500mm max]
14. Readout panel in front easy to read.
15. Air damping cylinder

A note from personal use: They are sensitive enough to detect the transference of oil or other matter from one's fingers, and rubbing the side of your nose was the worst. They exhibit ‘bounce around’ on readings with any heated samples over room temperature of say 50°c. So heat is going to be a major concern or destroyer of accuracy for EMdrive builders.
We would also go so far as to put  a machined solid 1” steel plate underneath the Balance say 20kgs when it was sitting on a bench [you would see movement of someone walking on the floor a metre away]

refine... refine ...refine....
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Sledgecrushr on 09/02/2015 12:11 AM
I am very interested in seeing the results from your heat testing.  I think it would be very important to heat the frustrum exactly in the same way that your magnetron does.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/02/2015 12:30 AM
I had a 160mm ceramic promised from one of my old contacts in the semi industry but it fell through. So, the only place I could find one was in China. I ordered it and asked to please ship it faster (than a slow boat), they never replied. They processed my order and posted this in the shipping details.
Arriving Thu, Sep 24 - Fri, Oct 16
Shipped
Track package
 99.5% High purity Round Aluminum Plate *1 Aluminum Ceramic Plate Setter Plate Disk crucible lid dia.160mm*7mm

I was bummed and even started looking in other places. Today it arrived, way ahead of schedule! I'm jazzed, as I'll be finally be able to put exact numbers to the frustum sizes and begin to construct it!

Good news today and also got in my wire mesh for the faraday cage. Tomorrow is going to be a good day.

Shell


 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/02/2015 01:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421843#msg1421843">Quote from: Silversheep2011 on 09/02/2015 12:03 AM</a>
These modern analytical beams are capable of measuring down with confidence amounts being transferred to a precision of one tenth of a milligram or one ten-thousandth of a gram, ±0.0001 g. but are limited to 160-200 gram capacity ranges.
The Mettler H10 will get you 10 ug, and it's about 50 years old. When it was introduced, it revolutionised chemistry labs' technique.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/02/2015 02:27 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421843#msg1421843">Quote from: Silversheep2011 on 09/02/2015 12:03 AM</a>
Suggestion for today:

We would also go so far as to put  a machined solid 1” steel plate underneath the Balance say 20kgs when it was sitting on a bench [you would see movement of someone walking on the floor a metre away]

refine... refine ...refine....
Great info!

I had to chuckle as one of the last machines I built the height measurement was so precise 1/4 um that when someone would walk next to it we could measure the deviation of the concrete and thereby the structure of the machine. It was impressive to think the floor upon which you stood could warp so much.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/02/2015 02:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421858#msg1421858">Quote from: deltaMass on 09/02/2015 01:07 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421843#msg1421843">Quote from: Silversheep2011 on 09/02/2015 12:03 AM</a>
These modern analytical beams are capable of measuring down with confidence amounts being transferred to a precision of one tenth of a milligram or one ten-thousandth of a gram, ±0.0001 g. but are limited to 160-200 gram capacity ranges.
The Mettler H10 will get you 10 ug, and it's about 50 years old. When it was introduced, it revolutionised chemistry labs' technique.
Id love to use a mettler, but I think the laser displacement sensor will suffice. It fires off to 40 mm +/- 10 mm and should get into micrometer range resolution. Have to study specs but think sample rate is 10 msec. Longer term project will be to connect to latop running labview. Think I'll set up to show displacement as a chart or o-scope display. Other sensors can be added, mainly environmentals. Be nice to standardize on a common display that others can use to run tests. Temp and humidity could be inputs as well as seismic reference if we wanted to get fancy. Funny other higher profile labs haven't done this...if I could, so should others with much more time and money.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/02/2015 02:49 AM
An idea to get rid of the thermal imbalance:

Why not to use on the other side of the balance a thermally and geometrically repesentative mockup of the EMDrive thruster system (frustum + magnetron) with the objective to reproduce and so to cancel most of the thermal perturbations effects. We could try, using electrical heaters and control thermistors, to reproduce on the mockup by a preliminary calibration, the same profil of temperatures experienced by the active device.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/02/2015 03:04 AM
It's quite a lot of work to do that, and to get it right, but I have to applaud your thinking there.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/02/2015 03:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421881#msg1421881">Quote from: deltaMass on 09/02/2015 03:04 AM</a>
It's quite a lot of work to do that, and to get it right, but I have to applaud your thinking there.

An other idea could be instead of building and calibrate a mockup, to replace it by a second identical EMDrive and to play with the important constant of time of the thermal effects:

1- We turn on the two EMThrusters installed on the two side of the balance.
2- We wait the thermal steady state of the system and mass balance it to have an equilibrium.
3- We turn off one of the EMTruster and with a thermal balance condition which should stay stable for a while, we measure the displacement of the balance. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/02/2015 03:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421887#msg1421887">Quote from: Mezzenile on 09/02/2015 03:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421881#msg1421881">Quote from: deltaMass on 09/02/2015 03:04 AM</a>
It's quite a lot of work to do that, and to get it right, but I have to applaud your thinking there.

An other idea could be instead of building and calibrate a mockup, to replace it by a second identical EMDrive and to play with the important constant of time of the thermal effects:

1- We turn on the two EMThrusters installed on the two side of the balance.
2- We wait the thermal steady state of the system and mass balance it to have an equilibrium.
3- We turn off one of the EMTruster and with a thermal balance condition which should stay stable for a while, we measure the displacement of the balance.

That's a great idea.

@SeeShells are you reading this? @Mezzenile has came up with a way to common mode out the thermal artefacts. And really, get right down to it, the two thrusters don't have to be "Identical," just close enough to subtract out the thermal effects by a significant factor. And any significant reduction in thermal will allow any real signal to rise toward the top!

Add: Of course it would really be best if the frustums were identical. Could your power splitter work with the magnetron at the center balance point and drive a frustum at each end of your balance, or is that to long a run for your co-ax?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 09/02/2015 03:56 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421730#msg1421730">Quote from: rfmwguy on 09/01/2015 04:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421722#msg1421722">Quote from: Rodal on 09/01/2015 04:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421717#msg1421717">Quote from: rfmwguy on 09/01/2015 04:10 PM</a>
NSF-1701 New Video - Static test of assembly today without electrodes in galinstan, which adds dampening and drag. When the galinstan was removed, there were wild movements of laser spot, as I noted when I first designed the test stand. Therefore I re-attached Doc's oil dampener, which greatly reduced vertical meanderings. The oil dampener addition and galinstan removal provided a laser spot displacement on the target of approximately the same amount. IOW, galinstan and no oil dampener and 500 mg weight added approximately equal no galinstan and oil dampener and 200 mg weight added. So, the drag/viscosity of galinstan is equal to about 300 mg...far more than I imagined.

Here's the video for detailed analysis:

https://youtu.be/jvjrJK90iYM

Excellent.  By the way, let's not forget that you also verified the importance of air currents in the motion of the beam, upon removal of the Galistan damping action.  There are still posters that question whether air currents are responsible for such motions.  As I understand it, you tested by adding 500 mg weight, hence there is no electromagnetic force involved in this test.
Doc, this test was 0, 200, 0 and 100 mg. No power applied.

Hi all,

I chopped it up at 1 fps. Not sure what happens around the 800 second mark. I put a grid on the montage just to make it easier to compare sections.  The xls file with the tracking data is attached.

As I mentioned the first time I did this, imageJ has the origin of the image at the top left so that's why the upwards movement of the laser produces a drop in the graph. I quite like this since it means frustum down=plot down. Easy enough to flip if people find it confusing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/02/2015 04:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421894#msg1421894">Quote from: aero on 09/02/2015 03:40 AM</a>
That's a great idea.

A third configuration for a good thermal effect suppression with two EMThrusters used in reverse (double thrust sensitivity) and thermal behavior symmetrisation via addition of some mechanical and heater mockup parts. Cf Pdf attached.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Croppa on 09/02/2015 05:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421704#msg1421704">Quote from: RERT on 09/01/2015 03:16 PM</a>
Folks - sorry to go AWOL after volunteering to do something, but my father has been visiting for some days. He's 81 - he doesn't need much looking after, but he does spend his days wandering through my house and garden pointing out chores which need doing, and organizing me to do them straight away...

I said I would do fourier analysis on the beam movements of rfmwguy's first experiment if someone would post the time-series, which was very soon done.

Of course, I omitted to mention that I would need the magnetron on/off audio signal to make much progress. With that I can match up the magnetron signal to the filtered beam signal and see what it tells us.

The rough analysis so far doesn't say much beyond what can be seen by eye in the plots posted,

R.

If you're still interested and need some numbers here is a file that you use to get the timing. I extracted the audio and downsampled the signal to 400 Hz to produce a manageable file. The first column is time and the second is amplitude (and a 3rd column when the amplitude is rectified so that all numbers are positive). The 5 min lower power run goes from around 264 seconds to 564 seconds and has 12 on/off cycles of 25 seconds each (10 or 11 seconds on).

I checked the timing of the extracted audio with the tracking movie that you have data from (based on the clicks of the light switch). It was off by 500 ms, so I added 500 ms of silence to the start of the audio before I downsampled. The times should closely match now.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/02/2015 05:53 AM
A summary of the 3 configurations proposed to reduce the thrust measurement error due to thermal effects : Cf attached Pdf
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/02/2015 07:08 AM
3 Test configurations to mitigate thermal perturbations:

(mini_434229EMThrustTest3.png) (viewer.php?id=434229EMThrustTest3.png)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kwertyops on 09/02/2015 08:19 AM
My tracking analysis - redundant to Croppa's of course. I've still got artifacting when the laser was swaying horizontally, but not quite as much. I've made rough measurements of the changes in pixels.

Still displaying stickiness, inconsistency in weight-to-distance movements..

Plus there's the issue of that small drop in the middle there that was unprompted and doesn't recover. Fulcrum slippage of some kind, maybe due to air currents. That kind of thing that seems very dangerous - if an event like that happened as the magnetron was turned on, that would very much give the appearance of downward thrust.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/02/2015 10:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421915#msg1421915">Quote from: Croppa on 09/02/2015 03:56 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421730#msg1421730">Quote from: rfmwguy on 09/01/2015 04:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421722#msg1421722">Quote from: Rodal on 09/01/2015 04:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421717#msg1421717">Quote from: rfmwguy on 09/01/2015 04:10 PM</a>
NSF-1701 New Video - Static test of assembly today without electrodes in galinstan, which adds dampening and drag. When the galinstan was removed, there were wild movements of laser spot, as I noted when I first designed the test stand. Therefore I re-attached Doc's oil dampener, which greatly reduced vertical meanderings. The oil dampener addition and galinstan removal provided a laser spot displacement on the target of approximately the same amount. IOW, galinstan and no oil dampener and 500 mg weight added approximately equal no galinstan and oil dampener and 200 mg weight added. So, the drag/viscosity of galinstan is equal to about 300 mg...far more than I imagined.

Here's the video for detailed analysis:

https://youtu.be/jvjrJK90iYM

Excellent.  By the way, let's not forget that you also verified the importance of air currents in the motion of the beam, upon removal of the Galistan damping action.  There are still posters that question whether air currents are responsible for such motions.  As I understand it, you tested by adding 500 mg weight, hence there is no electromagnetic force involved in this test.
Doc, this test was 0, 200, 0 and 100 mg. No power applied.

Hi all,

I chopped it up at 1 fps. Not sure what happens around the 800 second mark. I put a grid on the montage just to make it easier to compare sections.  The xls file with the tracking data is attached.

As I mentioned the first time I did this, imageJ has the origin of the image at the top left so that's why the upwards movement of the laser produces a drop in the graph. I quite like this since it means frustum down=plot down. Easy enough to flip if people find it confusing.

Croppa, clean and simple as usual.  :)

It takes a while for the oscillations to drop off.  In the first weight drop (200mg), they never went to zero.  It looks overall for any "reasonable" time frame, the deflection would be +- 3% of 200mg or a net limit resolution in this set up of 6 mg dropping to 2 or 3 over time.

If the delta is slower, induced oscillation may be less, but the maximum resolution in this settup appears to be 1-2 mg

edit:  Which translates to about 10-20 micro newtons... I think....  if I can count zeros correctly.  With oscillation +- 60 micro newtons.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RareSaturn on 09/02/2015 10:51 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421878#msg1421878">Quote from: Mezzenile on 09/02/2015 02:49 AM</a>
An idea to get rid of the thermal imbalance:

Why not to use on the other side of the balance a thermally and geometrically repesentative mockup of the EMDrive thruster system (frustum + magnetron) with the objective to reproduce and so to cancel most of the thermal perturbations effects. We could try, using electrical heaters and control thermistors, to reproduce on the mockup by a preliminary calibration, the same profil of temperatures experienced by the active device.

Brilliant.  Two emdrives, one on either end of the balance.  One resonating, one not.  Same heat pumped into both.... I love it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/02/2015 12:21 PM
Thanks once again for the great ideas and analysis! Looks like I'll have to bite the bullet and reconfigure the power going to the maggy. I think Shell is doing this, but I'll run 3 twisted wires about 4 feet to the end of the balance beam. The power feed will be at the center of the fulcrum, where the liquid metal (or whatever aqueous solution I try) will not have such an effect on moment arm displacement. So, to summarize:

1) Power supply feed at near the pivot point of fulcrum.
2) Twisted supply wires to end of beam and maggy..
3) Try other conductive liquids.
4) Keep Doc's oil dampener in use but add vertical plate to retard horizontal oscillations.
5) LDS for micrometer level resolution down the road.

Your/my test setup is improving! All open-source collaboration...well done folks.

Got 10' of the high voltage wire per a poster's suggestion a few pages ago from mcmaster carr
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/02/2015 02:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422136#msg1422136">Quote from: rfmwguy on 09/02/2015 12:21 PM</a>
Thanks once again for the great ideas and analysis! Looks like I'll have to bite the bullet and reconfigure the power going to the maggy. I think Shell is doing this, but I'll run 3 twisted wires about 4 feet to the end of the balance beam. The power feed will be at the center of the fulcrum, where the liquid metal (or whatever aqueous solution I try) will not have such an effect on moment arm displacement. So, to summarize:

1) Power supply feed at near the pivot point of fulcrum.
2) Twisted supply wires to end of beam and maggy..
3) Try other conductive liquids.
4) Keep Doc's oil dampener in use but add vertical plate to retard horizontal oscillations.
5) LDS for micrometer level resolution down the road.

Your/my test setup is improving! All open-source collaboration...well done folks.
It is a great place to throw those ideas against the wall, isn't it?

I'm also considering profiling from the magnetron waveguide to coax. I'm going to feed the coax right in the center of the pivot beam point with a stress relief loop from the top of the center scale support beam. If it's done correctly the coax profile will not obstruct movement in a non-linear way but act as a semi-spring damper. The center of the movement is quite small so it should be easy to profile. If it proves to be a issue then I think more about something else.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/02/2015 02:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422023#msg1422023">Quote from: Croppa on 09/02/2015 05:40 AM</a>

If you're still interested and need some numbers here is a file that you use to get the timing.
.......

Thanks a bunch, I've downloaded it and will take a look. R.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/02/2015 02:55 PM
Here's my new fulcrum design, what does everyone think?  ::)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/02/2015 03:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422182#msg1422182">Quote from: rfmwguy on 09/02/2015 02:55 PM</a>
Here's my new fulcrum design, what does everyone think?  ::)

Not sure, got me stumped.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 09/02/2015 03:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422186#msg1422186">Quote from: SeeShells on 09/02/2015 03:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422182#msg1422182">Quote from: rfmwguy on 09/02/2015 02:55 PM</a>
Here's my new fulcrum design, what does everyone think?  ::)

Not sure, got me stumped.
Shell

Seems a well-rooted concept.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/02/2015 04:21 PM
So, I've given this a lot of thought. While I don't want to detract from other's fund raising activitles, I've been asked if I accept donations. Until now, I have not. The reasons I decided to do so is the mounting personal expenses of this experiment being done correctly.

Laser Displacement Sensors, new wiring, software, etc are not cheap...so if you would like to help, you can. Do not feel obligated, but know that your help will go 100% to the "Citizen Scientist" project known as NSF-1701.

This is the only post I will make in this regard and I appreciate your efforts to date.

The link is simple, no splashy page: https://www.paypal.me/NSF1701

Cheers - and thanks in advance,
Dave
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: toddrmcallister on 09/02/2015 04:47 PM
Guess I can skip a few beers in the name of science : )

Thank you for your efforts and for sharing!

Regards,

trm
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/02/2015 06:10 PM
I've heard reference of using a https://greatscottgadgets.com/hackrf/ (https://greatscottgadgets.com/hackrf/)

or http://hackrfblue.com/ (http://hackrfblue.com/)

as a highly tunable signal source that could then be amplified.  Does anyone have experience working with one of these things?  It seems that its "intended" use is more as a receiver that can feed a signal into a PC for decryption than a transmitter. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/02/2015 06:14 PM
Anyone here have experience using paraview (https://www.paraview.org) with meep data, perhaps using the xdmf tool (http://comments.gmane.org/gmane.comp.science.electromagnetism.meep.general/5041) to create xdmf wrapper file for the h5 meep files?

I've got it working, but am trying to figure out how to drive it ...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/02/2015 07:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422242#msg1422242">Quote from: Eer on 09/02/2015 06:14 PM</a>
Anyone here have experience using paraview (https://www.paraview.org) with meep data, perhaps using the xdmf tool (http://comments.gmane.org/gmane.comp.science.electromagnetism.meep.general/5041) to create xdmf wrapper file for the h5 meep files?

I've got it working, but am trying to figure out how to drive it ...

I've had bad experience with it. Got it working but it's to much program for my machine, or for me, or for both. Anyway, no good luck with it and I've forgotten anything I may have learned.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/02/2015 07:32 PM

You bet. I'll send some.

Shell
Added...
Forgo that Starbucks Latte' Mocha for a little and let's help rfmwguy.
Everyone stepped up and helped me and donated a little something when I needed help to build and test this.
It's not cheap to do it right and I have to applaud what rfmwuy has done out of his own pocket but he is right, he needs a little help.
Let's help him "Do it right" and make it so, spit out the Latte' and help, good guy rfmwguy.



<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422214#msg1422214">Quote from: rfmwguy on 09/02/2015 04:21 PM</a>
So, I've given this a lot of thought. While I don't want to detract from other's fund raising activitles, I've been asked if I accept donations. Until now, I have not. The reasons I decided to do so is the mounting personal expenses of this experiment being done correctly.

Laser Displacement Sensors, new wiring, software, etc are not cheap...so if you would like to help, you can. Do not feel obligated, but know that your help will go 100% to the "Citizen Scientist" project known as NSF-1701.

This is the only post I will make in this regard and I appreciate your efforts to date.

The link is simple, no splashy page: https://www.paypal.me/NSF1701

Cheers - and thanks in advance,
Dave

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/02/2015 10:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422324#msg1422324">Quote from: Eer on 09/02/2015 09:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422267#msg1422267">Quote from: aero on 09/02/2015 07:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422242#msg1422242">Quote from: Eer on 09/02/2015 06:14 PM</a>
Anyone here have experience using paraview (https://www.paraview.org) with meep data, perhaps using the xdmf tool (http://comments.gmane.org/gmane.comp.science.electromagnetism.meep.general/5041) to create xdmf wrapper file for the h5 meep files?

I've got it working, but am trying to figure out how to drive it ...

I've had bad experience with it. Got it working but it's to much program for my machine, or for me, or for both. Anyway, no good luck with it and I've forgotten anything I may have learned.

Okay - I've made some progress with it.  Shout if interest gets going again.

Back to the task you set me - how do I know if we have resonance with the dipole antennae placements as I've made them?

Ed

answered via PM.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/03/2015 12:56 AM
26 deg C in shop...heat wave continues...nope, not going there. On the bright side the LDS arrived today. New HV wire from mcmaster arrives tomorrow. New wiring to nsf-1701 from power box to follow. No rest for the weary  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/03/2015 04:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422359#msg1422359">Quote from: rfmwguy on 09/03/2015 12:56 AM</a>
26 deg C in shop...heat wave continues...nope, not going there. On the bright side the LDS arrived today. New HV wire from mcmaster arrives tomorrow. New wiring to nsf-1701 from power box to follow. No rest for the weary  ;)

26C hot? That is just a nice spring day in Oz.

Apologises if any of the below has been covered. I don't read the forum everyday and may have missed earlier comments.

While being in bed sucks big time, did manage to find a few equations that may be of use in understanding the transmission / reflection losses (what is not transmitted through the mesh is reflected) from your copper mesh frustum walls.

From the equations and knowing the 3 dimensions of your mesh it should be easy to calc the reflection loss at 2.45GHz. As this is per bounce loss, I suspect the final loss after even a 100 bounces will be very significant.

As NSF-1701's end plates are not radius spherical to the vertex, there will be significant side wall bounces from the end plates.



Pages 274 - 276.

Do you have any plans to do a frustum return loss scan across the magnetrons output frequency range to see if there is resonance or not and if so to know what is the return loss dBs / VSWR / reflection coefficient and now much real forward power is entering the frustum and how much power is being reflected back inside the maganetron?

While it is your show to run your way, EW did do return loss scans to be sure they had resonance before pumping Rf energy into their frustum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 09/03/2015 05:54 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420761#msg1420761">Quote from: graybeardsyseng on 08/28/2015 07:18 PM</a>
I finally finished the loop antenna modeling exercise.  Not sure if this is still useful but I will post here.   Likely the patterns are the most useful part - as they should give some idea of what modes can be stimulated.   

These models and results are made using a version of the NEC codes (specifically EZNEC).  NEC antenna modeling is not perfect but if you stay within the constraints it can produce qualitatively useful results.   As with all such models, quantitative results are highly dependent on many factors including geometry, signal quality, and many more.   Hopefully these will be of use - particularly if the loops are in a spherical chicken in a vacuum.

I modeled three sizes of antenna 1/2, 1, and 2 wavelength circumference, at three different heights - 1/4, 1/2 and 1 wavelength.   Also modeled each of these configurations for loops both parallel to and normal to their ground plane.

Sorry for how long this took - as some of you know I have been in the process of retiring and unfortunately this exercise mostly had to take place late in evening after all other boring but necessary stuff had been done.  I am now free and hope to start detailed planning for my own DIY experiments soon.

Herman
Herman,
Here's a 4NEC2 file of a small loop, I ran cases for .36 inch dia and am posting the NASA 0.55 inch loop. They serve as an approximate starting point in free space, in a cavity the impedance will be reduced by the mirroring of the walls. Impedance is 133-j60 and SWR 3.28. You will have to rename the NEC file, replace dot with a period and delete txt. The images are bmp files, replace dot with a period and remove txt.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: OttO on 09/03/2015 08:31 AM
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 09/03/2015 11:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/03/2015 12:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422436#msg1422436">Quote from: VAXHeadroom on 09/03/2015 11:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.

What about heating?
Most of those extrusion type filaments start to loose their structural rigidity around 80-90°C.

You're speaking about diameter and circular printbed... using a delta printer? By far the most Z accurate printer you can have... (have one myself and VERY satisfied with it)

What type of plastic did you use to copperplate? I did not try copper plating myself , but it sounds an interesting approach, compared to the copper filament printing, which uses a mix of copper particles and plastic instead....

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/03/2015 12:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422436#msg1422436">Quote from: VAXHeadroom on 09/03/2015 11:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.
I love this stuff as the dicing saws we designed were an X, Y, Z & T movement axis <1um accuracy as well. One issue I think they still would be having using servos or steppers and an encoder feedback system is accumulated step errors of an axis.  Even high count encoders in a quadrature mode will show this. But maybe they got it corrected where they don't. It was one of our IPs we never disclosed not to have indexing and accumulative errors.

This would be a great way to not only model the frustum but to do everything from the antenna(s) and or waveguide(s) insertion. Even screw in tunable endplates with curved surfaces could be done. A built in cooling line throughout the frustum for chilled water could even be implemented with line connectors! Several other things come to mind that would be impossible with regular machining.

Maybe next step, next design, I need to finalize this current layout.

Shell

PS: Picking the right plastics would be critical but not as much as being a good thermal conductor.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/03/2015 12:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422398#msg1422398">Quote from: cee on 09/03/2015 05:54 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420761#msg1420761">Quote from: graybeardsyseng on 08/28/2015 07:18 PM</a>
I finally finished the loop antenna modeling exercise.   I am now free and hope to start detailed planning for my own DIY experiments soon.

Herman
Herman,
Here's a 4NEC2 file of a small loop, I ran cases for .36 inch dia and am posting the NASA 0.55 inch loop. They serve as an approximate starting point in free space, in a cavity the impedance will be reduced by the mirroring of the walls. Impedance is 133-j60 and SWR 3.28. You will have to rename the NEC file, replace dot with a period and delete txt. The images are bmp files, replace dot with a period and remove txt.
Cee, I like the pattern! Very nice work. Herman, beautiful. I guess I need to take more time from building to doing and learning NEC modeling.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 09/03/2015 12:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422443#msg1422443">Quote from: Flyby on 09/03/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422436#msg1422436">Quote from: VAXHeadroom on 09/03/2015 11:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.

What about heating?
Most of those extrusion type filaments start to loose their structural rigidity around 80-90°C.

You're speaking about diameter and circular printbed... using a delta printer? By far the most Z accurate printer you can have... (have one myself and VERY satisfied with it)

What type of plastic did you use to copperplate? I did not try copper plating myself , but it sounds an interesting approach, compared to the copper filament printing, which uses a mix of copper particles and plastic instead....

We actually copperplated a billiard ball, but I have also seen results from this company on SLA printed plastics.
Yes, I have a delta arm machine - a SeeMeCNC RoStock MAX V2.  Love this machine! Fast, accurate, and reliable.  I haven't tried to push the resolution limits yet - been too busy printing things for customers!
I have never done delamination testing over temperature - and never needed to know so I've not looked it up.  But I'm SURE there's good info out there...
I am printing in carbon fiber impregnated PLA (from ProtoPasta), plain PLA, and ABS.  Haven't tried any of the metal impregnated plastics yet, but they're on my list - I wonder how they'd transfer heat?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/03/2015 02:18 PM
Hi folks -

Attached is what I made of the posted data from Croppa et al on NSF1702 FT1.

If I'm getting the sign conventions right, it appears the beam is being deflected down, i.e. frustrum up, when the magnetron is running, and relaxes back when it is off. I would really love to see what happens with this experiment repeated with the original configuration reversed, with the frustrum pointing the other way and the magnetron back at the original end of the frustrum. That said, things have moved on...

I've had to apply enough guesswork to various timings that the analysis would need to be checked before drawing conclusions, but the chart is at least 'Quite Interesting'.

The data is 1000 frames from frame 1080 in the video listing. I needed 4 fps to make the total run last the same time in audio and video.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/03/2015 02:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422470#msg1422470">Quote from: RERT on 09/03/2015 02:18 PM</a>
Hi folks -

Attached is what I made of the posted data from Croppa et al on NSF1702 FT1.

If I'm getting the sign conventions right, it appears the beam is being deflected down, i.e. frustrum up, when the magnetron is running, and relaxes back when it is off. I would really love to see what happens with this experiment repeated with the original configuration reversed, with the frustrum pointing the other way and the magnetron back at the original end of the frustrum. That said, things have moved on...

I've had to apply enough guesswork to various timings that the analysis would need to be checked before drawing conclusions, but the chart is at least 'Quite Interesting'.

The data is 1000 frames from frame 1080 in the video listing. I needed 4 fps to make the total run last the same time in audio and video.

R.

Let's analyze these experimental results taking into account the hundreds of pages of these EM Drive threads.

This behavior (the RFMWGUY frustum moving in the direction pointing towards the big base) is the complete opposite of:

1) The measurements reported by NASA (motion and force pointing towards the small base)
2) The measurements reported by Tajmar  (motion and force pointing towards the small base)
3) The measurements reported by Shawyer  (motion towards the small base)
4) The Meep analysis
5) The Shawyer equation
6) The McCulloch equation and analysis
7) Dr. "Notsosureofit"'s equation
8) Todd Desiato's "WarpTech" theory


and they are in agreement with:

1) Thermal convection moving fustrum up due to natural thermal convection current set up by magnetron on top of big base which is what gets hottest by far, as shown by measurements

This is the same conclusion that RFMWGUY came to, early on:  RFMWGUY measurements show thermal convection current.

There is absolutely nothing: no equation, no theory, no previous experimental result that would support movement of the frustum up, pointing towards the big base, due to electromagnetic stress, with this setup: no dielectric insert, and magnetron located at the big base.

The most that the "EM Drive" believers can hold on to here is that:

1) The RFMWGUY EM Drive test is not resonating (effectively meaning a Q below 1,000) in the RFMWGUY experiments
and/or
2) Whatever "EM Drive thrust force" taking place pointing towards the small base is so small, so tiny, that it is completely overwhelmed by the thermal lift of the magnetron.  This force would have to be as small as measured by Tajmar.

So, this experiment by RFMWGUY either:

a) it is not in resonance
or
b) it nullifies the reported claims of Shawyer and Yang if the RFMWGUY EM Drive is resonating with a high Q

*********************

Ever since Maxwell showed that electromagnetic fields can exert pressure, experimental verification of Maxwell's electromagnetic stress had to contend with what became known as "the gas effect,"

It was only when experiments were conducted in vacuum, at the turn of the 19th century into the 20th century, that electromagnetic stress was able to be properly measured.

Neither Shawyer or Yang ever reported a single test conducted in vacuum.
The only organizations that have conducted tests in vacuum (NASA and TU Dresden) have reported force/InputPower values that are several orders of magnitude smaller than the values reported by Shawyer or Yang.

The importance of the thermal natural convection in air shown by RFMWGUY in this experiment is consistent with the well known scientific history of electromagnetic pressure measurements.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/03/2015 03:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422450#msg1422450">Quote from: VAXHeadroom on 09/03/2015 12:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422443#msg1422443">Quote from: Flyby on 09/03/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422436#msg1422436">Quote from: VAXHeadroom on 09/03/2015 11:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.

What about heating?
Most of those extrusion type filaments start to loose their structural rigidity around 80-90°C.

You're speaking about diameter and circular printbed... using a delta printer? By far the most Z accurate printer you can have... (have one myself and VERY satisfied with it)

What type of plastic did you use to copperplate? I did not try copper plating myself , but it sounds an interesting approach, compared to the copper filament printing, which uses a mix of copper particles and plastic instead....

We actually copperplated a billiard ball, but I have also seen results from this company on SLA printed plastics.
Yes, I have a delta arm machine - a SeeMeCNC RoStock MAX V2.  Love this machine! Fast, accurate, and reliable.  I haven't tried to push the resolution limits yet - been too busy printing things for customers!
I have never done delamination testing over temperature - and never needed to know so I've not looked it up.  But I'm SURE there's good info out there...
I am printing in carbon fiber impregnated PLA (from ProtoPasta), plain PLA, and ABS.  Haven't tried any of the metal impregnated plastics yet, but they're on my list - I wonder how they'd transfer heat?

All depends on what temperatures one has to expect when using a 700W+ microwave generator.
When I read that R.Shawyer has burned through his frustum coppersheet walls on a few occasions, i fear all those type of 3Dprint materials will not last long before collapsing or even start to burn...
I'm not keen on even trying it....as i'm pretty sure it will fail.

The only solution would to drastically lower the power input. Question is then, will we then ever see any results from those low energy inputs? (keeping the baby-frustum in mind)

I think overall internal temperature should not exceed 70-80°C to use a copper plated filament 3Dprinted frustum...I'll have a heat conductivity test on the copper filament. Was going to test it anyway... :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 09/03/2015 03:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422479#msg1422479">Quote from: Rodal on 09/03/2015 02:42 PM</a>
The most that the "EM Drive" believers can hold on to here is that:

1) The RFMWGUY EM Drive test is not resonating (effectively meaning a Q below 1,000) in the RFMWGUY experiments
and/or
2) Whatever "EM Drive thrust force" taking place pointing towards the small base is so small, so tiny, that it is completely overwhelmed by the thermal lift of the magnetron.  This force would have to be as small as measured by Tajmar.

So, this experiment by RFMWGUY either:

a) it is not in resonance
or
b) it nullifies the reported claims of Shawyer and Yang if the RFMWGUY EM Drive is resonating with a high Q

Assuming NSF-1701 is resonating, what is the upper limit on a possible thrust towards the small base and how would that compare to a photon rocket?

Measuring the Q of NSF-1701 is important to see if this is a valid test with a null result.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 09/03/2015 03:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422480#msg1422480">Quote from: Flyby on 09/03/2015 03:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422450#msg1422450">Quote from: VAXHeadroom on 09/03/2015 12:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422443#msg1422443">Quote from: Flyby on 09/03/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422436#msg1422436">Quote from: VAXHeadroom on 09/03/2015 11:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.

What about heating?
Most of those extrusion type filaments start to loose their structural rigidity around 80-90°C.

You're speaking about diameter and circular printbed... using a delta printer? By far the most Z accurate printer you can have... (have one myself and VERY satisfied with it)

What type of plastic did you use to copperplate? I did not try copper plating myself , but it sounds an interesting approach, compared to the copper filament printing, which uses a mix of copper particles and plastic instead....

We actually copperplated a billiard ball, but I have also seen results from this company on SLA printed plastics.
Yes, I have a delta arm machine - a SeeMeCNC RoStock MAX V2.  Love this machine! Fast, accurate, and reliable.  I haven't tried to push the resolution limits yet - been too busy printing things for customers!
I have never done delamination testing over temperature - and never needed to know so I've not looked it up.  But I'm SURE there's good info out there...
I am printing in carbon fiber impregnated PLA (from ProtoPasta), plain PLA, and ABS.  Haven't tried any of the metal impregnated plastics yet, but they're on my list - I wonder how they'd transfer heat?

All depends on what temperatures one has to expect when using a 700W+ microwave generator.
When I read that R.Shawyer has burned through his frustum coppersheet walls on a few occasions, i fear all those type of 3Dprint materials will not last long before collapsing or even start to burn...
I'm not keen on even trying it....as i'm pretty sure it will fail.

The only solution would to drastically lower the power input. Question is then, will we then ever see any results from those low energy inputs? (keeping the baby-frustum in mind)

I think overall internal temperature should not exceed 70-80°C to use a copper plated filament 3Dprinted frustum...I'll have a heat conductivity test on the copper filament. Was going to test it anyway... :)
Still would be useful for low level measurements to characterize the frustum design itself, like the conical angle that was so much under discussion, as well as some novel frustum related shapes that were discussed here.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/03/2015 03:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422488#msg1422488">Quote from: cee on 09/03/2015 03:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422480#msg1422480">Quote from: Flyby on 09/03/2015 03:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422450#msg1422450">Quote from: VAXHeadroom on 09/03/2015 12:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422443#msg1422443">Quote from: Flyby on 09/03/2015 12:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422436#msg1422436">Quote from: VAXHeadroom on 09/03/2015 11:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422420#msg1422420">Quote from: OttO on 09/03/2015 08:31 AM</a>
Interesting process to make a wave guide by 3D printing:

http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=7217811&tag=1

I have comparable FDM (plastic extrusion style) machines and know where to get this kind of copper plating done.  The largest machine I currently own will do 11" diameter and 14.75" tall.  The bed is circular, so the largest square cross section I can build is about a 7.5" square - not quite big enough for the designs currently being constructed (the large bases are about 11.6" diameter) to be built in one piece...
But I've had the copper plating done for stuff at work and the work comes out beautiful.

What about heating?
Most of those extrusion type filaments start to loose their structural rigidity around 80-90°C.

You're speaking about diameter and circular printbed... using a delta printer? By far the most Z accurate printer you can have... (have one myself and VERY satisfied with it)

What type of plastic did you use to copperplate? I did not try copper plating myself , but it sounds an interesting approach, compared to the copper filament printing, which uses a mix of copper particles and plastic instead....

We actually copperplated a billiard ball, but I have also seen results from this company on SLA printed plastics.
Yes, I have a delta arm machine - a SeeMeCNC RoStock MAX V2.  Love this machine! Fast, accurate, and reliable.  I haven't tried to push the resolution limits yet - been too busy printing things for customers!
I have never done delamination testing over temperature - and never needed to know so I've not looked it up.  But I'm SURE there's good info out there...
I am printing in carbon fiber impregnated PLA (from ProtoPasta), plain PLA, and ABS.  Haven't tried any of the metal impregnated plastics yet, but they're on my list - I wonder how they'd transfer heat?

All depends on what temperatures one has to expect when using a 700W+ microwave generator.
When I read that R.Shawyer has burned through his frustum coppersheet walls on a few occasions, i fear all those type of 3Dprint materials will not last long before collapsing or even start to burn...
I'm not keen on even trying it....as i'm pretty sure it will fail.

The only solution would to drastically lower the power input. Question is then, will we then ever see any results from those low energy inputs? (keeping the baby-frustum in mind)

I think overall internal temperature should not exceed 70-80°C to use a copper plated filament 3Dprinted frustum...I'll have a heat conductivity test on the copper filament. Was going to test it anyway... :)
Still would be useful for low level measurements to characterize the frustum design itself, like the conical angle that was so much under discussion, as well as some novel frustum related shapes that were discussed here.
If you're going to 3D print it why not treat it like a paper cup of water that is set on the fire that never burns? Not a good scientific a analogy but gets the point across. Make the internal sidewalls of the frustum a spiral cavity that you can insert chilled water through. Like this quick idea sketch that shows the outer and inner skin cut away.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/03/2015 03:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422479#msg1422479">Quote from: Rodal on 09/03/2015 02:42 PM</a>


So, this experiment by RFMWGUY either:

a) it is not in resonance
or
b) it nullifies the reported claims of Shawyer and Yang if the RFMWGUY EM Drive is resonating with a high Q

...

Has anyone experimentally verified that a perforated frustum can resonate with a high Q?

I would bet he is very close to resonance, but the quality is probably much lower than 1000. Fooling around with our cylinder revealed that changing the movable plate by ~50 thou could result in dramatic differences in quality as seen by these S11 plots. Apples and oranges, yes, but making a resonator with a bandwidth of 2.45 MHz seems very difficult without some sort of tuning mechanism.   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/03/2015 04:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422479#msg1422479">Quote from: Rodal on 09/03/2015 02:42 PM</a>
1) The RFMWGUY EM Drive test is not resonating (effectively meaning a Q below 1,000) in the RFMWGUY experiments
and/or
2) Whatever "EM Drive thrust force" taking place pointing towards the small base is so small, so tiny, that it is completely overwhelmed by the thermal lift of the magnetron.  This force would have to be as small as measured by Tajmar.


3.  For some reason not currently apparent the effect requires, if not a flat surface, one without a large hole in it.

4.  Cannae is right and electrical impedance has something to do with the effect.  Perhaps changes in impedance resulting from the use of a mesh are bricking the device.  (Did Cannae's symmetrical superconducting thruster move in the direction of the superconductor?)

5. A minimum power level is required to produce an effect.  The power is not available on the frequency which the device is resonant.

Quote
*********************

Ever since Maxwell showed that electromagnetic fields can exert pressure, experimental verification of Maxwell's electromagnetic stress had to contend with what became known as "the gas effect,"

It was only when experiments were conducted in vacuum, at the turn of the 19th century into the 20th century, that electromagnetic stress was able to be properly measured.

Neither Shawyer or Yang ever reported a single test conducted in vacuum.
The only organizations that have conducted tests in vacuum (NASA and TU Dresden) have reported force/InputPower values that are several orders of magnitude smaller than the values reported by Shawyer or Yang.

The importance of the thermal natural convection in air shown by RFMWGUY in this experiment is consistent with the well known scientific history of electromagnetic pressure measurements.

So are you suggesting that the way to go forward shrink the drive size by using a higher frequency, and put the entire thing in a small vacuum chamber (most likely homemade) then weigh the entire thing on a scale or beam in the chamber.  Biggest problem I see is not melting/cracking whatever you use.  I wonder if you could modify an aquarium to get the desired effect?  I wonder if we could get NSF-1701 or C-E into one.

As for moving up frequency, just saying that 10ghz HAM band is out there.  God help you if you have an rf leak though.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/03/2015 04:49 PM
Apologies, in some previous post I put University of Saskatoon, that should have read University of Saskatchewan in Saskatoon. Apologies (I am a UofC, Athabasca and UND grad). My brother is doing his electrical engineering degree there and I have proposed these experiments as their final team project with external funding and provided industrial magnetron setup. You'll note that I myself am NOT an electrical engineer (I am Mechanical and Chemical), my knowledge of RF was limited to potential piloting of using RF for in situ heating of bitumen deposits. Having fun learning about RF technology and the "quantum vacuum" regardless of if the EM-Drive/Q-Thruster phenomena is real or not. I think we can all agree would be more "fun" if this is real.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/03/2015 05:01 PM

Higher powers you pretty much have to fire the unit submersed in low temp water with a mixer or a cooling nitrogen blanket. At 930MHz, 100kW you've got like 2m2 surface area, you are just over the limit for immersion cooling with water. Now the good news with a waveguide launcher is I guess you can just copper tube your RF to the entry point that your magnetron and electronics don't have to be anywhere near the frustrum (indeed the magnetron is water cooled anyway with a isolator using a waterload (this is required to absorb any downstream reflected energy before it gets back to magnetron and would cause permanent damage.... modelling needed to see if this hurts resonance in the frustrum) so you've got water everywhere anyway. Looks like 60kW you can do water cooled... but then you have no cyrogenic low temps which help Q factor.

Quote
All depends on what temperatures one has to expect when using a 700W+ microwave generator.
When I read that R.Shawyer has burned through his frustum coppersheet walls on a few occasions, i fear all those type of 3Dprint materials will not last long before collapsing or even start to burn...
I'm not keen on even trying it....as i'm pretty sure it will fail.

The only solution would to drastically lower the power input. Question is then, will we then ever see any results from those low energy inputs? (keeping the baby-frustum in mind)

I think overall internal temperature should not exceed 70-80°C to use a copper plated filament 3Dprinted frustum...I'll have a heat conductivity test on the copper filament. Was going to test it anyway... :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/03/2015 05:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422497#msg1422497">Quote from: zellerium on 09/03/2015 03:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422479#msg1422479">Quote from: Rodal on 09/03/2015 02:42 PM</a>


So, this experiment by RFMWGUY either:

a) it is not in resonance
or
b) it nullifies the reported claims of Shawyer and Yang if the RFMWGUY EM Drive is resonating with a high Q

...

Has anyone experimentally verified that a perforated frustum can resonate with a high Q?

I would bet he is very close to resonance, but the quality is probably much lower than 1000. Fooling around with our cylinder revealed that changing the movable plate by ~50 thou could result in dramatic differences in quality as seen by these S11 plots. Apples and oranges, yes, but making a resonator with a bandwidth of 2.45 MHz seems very difficult without some sort of tuning mechanism.
A pure magnitude plot don't tell anything about the possible under- or over-coupling, both looks very equal. Much better is a plot of the complex plane (beside the mag plot ;) ).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/03/2015 05:39 PM
I need a movie.

https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing)

This is the current status of the loop antenna and I need some help to explain what I'm not seeing. It looks nice but I don't see proper behaviour of current reversal. But then, I don't know for sure what that would be so that's what I need help with. Time scale - I'm not accustom to thinking at the speed of light and here I have 3 complete cycles of the drive
output every 0.05 cycle. Maybe I should just output at every computational time step.
If someone would be so kind as to post a movie for me I can much better explain my question.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/03/2015 05:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422542#msg1422542">Quote from: aero on 09/03/2015 05:39 PM</a>
I need a movie.

https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing)

This is the current status of the loop antenna and I need some help to explain what I'm not seeing. It looks nice but I don't see proper behaviour of current reversal. But then, I don't know for sure what that would be so that's what I need help with. Time scale - I'm not accustom to thinking at the speed of light and here I have 3 complete cycles of the drive
output every 0.05 cycle. Maybe I should just output at every computational time step.
If someone would be so kind as to post a movie for me I can much better explain my question.
Great work aero! Looks very nice :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/03/2015 07:20 PM
Dr. Rodal -

I think the appropriate attitude to adopt is empirical, not theoretical. The reason I think that is that we are dealing with an 'impossible' phenomenon, so any theory is necessarily inadequate. Simulations and earlier experiments can guide future work, given the alternative is pure trial and error, which is not attractive.

What I don't think is appropriate is to neglect to follow up apparent effects because our theory says they are impossible. The whole idea is impossible in theory, after all.

I've presented some ideas that strongly suggest an effect correlated with magnetron operation in rfmwguy's first test. I agree with you, it's probably an artefact. Turning the frustum upside down and repeating the experiment will provide data for or against the idea of it being an artefact. Not doing the experiment because we think we know better will just leave a loose end.

Lastly, I think this is one of only a couple of hints of some EMdrive effect in the data which has been presented so far. This seems to me to make it even more important to follow it up, though of course it's up to rfmwguy's what he does.

Regards,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/03/2015 07:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422542#msg1422542">Quote from: aero on 09/03/2015 05:39 PM</a>
I need a movie.

https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing)

This is the current status of the loop antenna and I need some help to explain what I'm not seeing. It looks nice but I don't see proper behaviour of current reversal. But then, I don't know for sure what that would be so that's what I need help with. Time scale - I'm not accustom to thinking at the speed of light and here I have 3 complete cycles of the drive
output every 0.05 cycle. Maybe I should just output at every computational time step.
If someone would be so kind as to post a movie for me I can much better explain my question.

(My observation is that) the movie shown by X-Ray shows a 180 degree per cycle around the circumference.  (Pi per cycle).

Thus, you need 2 such cycles for a complete revolution (2 Pi) of this pattern:

(http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1063913;image)

Is that what you were looking for?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/03/2015 08:10 PM
@aero
Questions about your loop:
1) Is the length of the loop equal to 1lambda (it looks like that)?
2) Shows the visible pattern the H field component in the z direction? The file names suggest that...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/03/2015 08:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422546#msg1422546">Quote from: X_RaY on 09/03/2015 05:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422542#msg1422542">Quote from: aero on 09/03/2015 05:39 PM</a>
I need a movie.

https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRHpqYTU0TDc3RHM&usp=sharing)

This is the current status of the loop antenna and I need some help to explain what I'm not seeing. It looks nice but I don't see proper behaviour of current reversal. But then, I don't know for sure what that would be so that's what I need help with. Time scale - I'm not accustom to thinking at the speed of light and here I have 3 complete cycles of the drive
output every 0.05 cycle. Maybe I should just output at every computational time step.
If someone would be so kind as to post a movie for me I can much better explain my question.
Great work aero! Looks very nice :)
Second that but qualify, nice work X-ray too.
Just got in and catching up.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/03/2015 09:21 PM
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/03/2015 09:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422589#msg1422589">Quote from: X_RaY on 09/03/2015 08:10 PM</a>
@aero
Questions about your loop:
1) Is the length of the loop equal to 1lambda (it looks like that)?
2) Shows the visible pattern the H field component in the z direction? The file names suggest that...

I decided that we need to see more data. The previous movie was for a time slice every 10 computational cycles, every 10 time steps. I made a new run outputting the image at every time step. The image is of the z component of the magnetic field. The circumference of the loop is 3 wavelengths. That's just so the small images will show on my computer screen.

https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing)

The problem that I don't understand has to do with the cycling of the drive current. As it stands, the complete loop is regenerated at every time step so as the current in the loop reverses direction the complete loop current fades away as current passes through zero. But at the speed of the current and the very fine resolution of the simulation, is that what really happens? It takes 200 time steps for the curent to make a complete circut of the loop so how can the current at a point 100 time steps behind (half way around the loop) go to zero at the same time as the drive current?

Same thing at power on. The complete loop is excited at power on but shouldn't the points on the loop be excited in turn, one more point per time step (assuming the loop points are synchronized with speed of current)?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/03/2015 09:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422613#msg1422613">Quote from: SeeShells on 09/03/2015 09:21 PM</a>
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum :)

I see that it has now been published in:

Journal of Modern Physics, 2015, 6, 1308-1320

One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it.  The paper intends to address the issue of inmutability and undegredability of the QV.  In Dr. White's  hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold. 


**************************************************

This is an open access peer-reviewed journal that has a

Google h5-index=13    h5-median   =19

https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy

(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/03/2015 10:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422575#msg1422575">Quote from: RERT on 09/03/2015 07:20 PM</a>
Dr. Rodal -

I think the appropriate attitude to adopt is empirical, not theoretical. The reason I think that is that we are dealing with an 'impossible' phenomenon, so any theory is necessarily inadequate. Simulations and earlier experiments can guide future work, given the alternative is pure trial and error, which is not attractive.

What I don't think is appropriate is to neglect to follow up apparent effects because our theory says they are impossible. The whole idea is impossible in theory, after all.

I've presented some ideas that strongly suggest an effect correlated with magnetron operation in rfmwguy's first test. I agree with you, it's probably an artefact. Turning the frustum upside down and repeating the experiment will provide data for or against the idea of it being an artefact. Not doing the experiment because we think we know better will just leave a loose end.

Lastly, I think this is one of only a couple of hints of some EMdrive effect in the data which has been presented so far. This seems to me to make it even more important to follow it up, though of course it's up to rfmwguy's what he does.

Regards,

R.
The harmonic signature of the RF power signal fed by the magnetron into the frustum has not been considered so far. The level and phasing of the second harmonic of the frequency for which the transfert of energy in the cavity is maximal may be the other key factor which makes the thrust phenomena possible.
I have found the rationale for this hypothesis in the writings of James F. Woodward who at my knowledge is alone to have proposed  consistent theory and experiments about Machian mass fluctuation and its use for thrust generation without local momentum conservation (what we are all looking for). Even if at first sight the RF cavity device we are working on has little to see with the  Woodward device (electrical capacities with PZT crystals), it is fully possible that they use both the same basic mechanism found and tested by Woodward : Generation by the fundamental power signal of two kinds of Periodic Mass Fluctuation, one of which is at two times the fundamental frequency and then generation via the second harmonic of a net thrust by pushing on an object made more massive by this mass fluctuation and then pulling it back when it is in a mass-reduced state.

In Woodward mind, the presence of this second harmonic seems absolutely necessary for a Machian thrust to appear. More over the phase of this harmonic could very well control the direction of the thrust.

It is why I suggest to characterize the harmonics of the RF signal fed in the cavity (via a spectrum analyser connected to a port of a test coupler) and to try to calculate the electromagnetic field at the second harmonic frequency inside the cavity. The measurement/control  of the dephasing of the second harmonic would require some serious thinking ...  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/03/2015 10:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422621#msg1422621">Quote from: Rodal on 09/03/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422613#msg1422613">Quote from: SeeShells on 09/03/2015 09:21 PM</a>
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum :)

I see that it has now been published in:

Journal of Modern Physics, 2015, 6, 1308-1320

One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it.  The paper intends to address the issue of inmutability and undegredability of the QV.  In Dr. White's  hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold. 


**************************************************

This is an open access peer-reviewed journal that has a

Google h5-index=13    h5-median   =19

https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy

(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.

Thanks for the reply, I had not seen it.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/03/2015 10:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422635#msg1422635">Quote from: Mezzenile on 09/03/2015 10:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422575#msg1422575">Quote from: RERT on 09/03/2015 07:20 PM</a>
Dr. Rodal -

I think the appropriate attitude to adopt is empirical, not theoretical. The reason I think that is that we are dealing with an 'impossible' phenomenon, so any theory is necessarily inadequate. Simulations and earlier experiments can guide future work, given the alternative is pure trial and error, which is not attractive.

What I don't think is appropriate is to neglect to follow up apparent effects because our theory says they are impossible. The whole idea is impossible in theory, after all.

I've presented some ideas that strongly suggest an effect correlated with magnetron operation in rfmwguy's first test. I agree with you, it's probably an artefact. Turning the frustum upside down and repeating the experiment will provide data for or against the idea of it being an artefact. Not doing the experiment because we think we know better will just leave a loose end.

Lastly, I think this is one of only a couple of hints of some EMdrive effect in the data which has been presented so far. This seems to me to make it even more important to follow it up, though of course it's up to rfmwguy's what he does.

Regards,

R.
The harmonic signature of the RF power signal fed by the magnetron into the frustum has not been considered so far. The level and phasing of the second harmonic of the frequency for which the transfert of energy in the cavity is maximal may be the other key factor which makes the thrust phenomena possible.
I have found the rationale for this hypothesis in the writings of James F. Woodward who at my knowledge is alone to have proposed  consistent theory and experiments about Machian mass fluctuation and its use for thrust generation without local momentum conservation (what we are all looking for). Even if at first sight the RF cavity device we are working on has little to see with the  Woodward device (electrical capacities with PZT crystals), it is fully possible that they use both the same basic mechanism found and tested by Woodward : Generation by the fundamental power signal of two kinds of Periodic Mass Fluctuation, one of which is at two times the fundamental frequency and then generation via the second harmonic of a net thrust by pushing on an object made more massive by this mass fluctuation and then pulling it back when it is in a mass-reduced state.

In Woodward mind, the presence of this second harmonic seems absolutely necessary for a Machian thrust to appear. More over the phase of this harmonic could very well control the direction of the thrust.

It is why I suggest to characterize the harmonics of the RF signal fed in the cavity (via a spectrum analyser connected to a port of a test coupler) and to try to calculate the electromagnetic field at the second harmonic frequency inside the cavity. The measurement/control  of the dephasing of the second harmonic would require some serious thinking ...  :)
Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.

Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert.   Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum.  You are welcome to contact Prof. Woodward to find out whether my understanding is up to date (and if so, whether your understanding of his theory is being properly applied to an EM Drive without any dielectric insert).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 09/03/2015 10:33 PM
This made me think about the good ol' times when we could get a good picture of what the EagleWorks team was doing. With all the privileges of first hand information that entails. I just wish someone at Dresden was so forthcoming as Paul March was. But now we have to live with whatever we can get.

Anyone knows what are they up to now?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/03/2015 10:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422640#msg1422640">Quote from: tchernik on 09/03/2015 10:33 PM</a>
This made me think about the good ol' times when we could get a good picture of what the EagleWorks team was doing. With all the privileges of first hand information that entails. I just wish someone at Dresden was so forthcoming as Paul March was. But now we have to live with whatever we can get.

Anyone knows what are they up to now?
In order not to jeopardize any of the employees at NASA Eagleworks, unfortunately we really have to wait until they are given official permission by NASA officials for them to disclose any of their research.

If interested,  I suggest writing to your Congressman, asking she/he to fully fund NASA Eagleworks efforts and to allow them to disclose and discuss their research.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/03/2015 10:47 PM
The latest I have permission to mention from EW is "we are working on a peer reviewed test report that will included all our vacuum testing to date that will be published by the end of the calendar year. "
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 09/03/2015 11:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422615#msg1422615">Quote from: aero on 09/03/2015 09:22 PM</a>
I decided that we need to see more data. The previous movie was for a time slice every 10 computational cycles, every 10 time steps. I made a new run outputting the image at every time step. The image is of the z component of the magnetic field. The circumference of the loop is 3 wavelengths. That's just so the small images will show on my computer screen.

https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing)

The problem that I don't understand has to do with the cycling of the drive current. As it stands, the complete loop is regenerated at every time step so as the current in the loop reverses direction the complete loop current fades away as current passes through zero. But at the speed of the current and the very fine resolution of the simulation, is that what really happens? It takes 200 time steps for the curent to make a complete circut of the loop so how can the current at a point 100 time steps behind (half way around the loop) go to zero at the same time as the drive current?

Same thing at power on. The complete loop is excited at power on but shouldn't the points on the loop be excited in turn, one more point per time step (assuming the loop points are synchronized with speed of current)?

I'm just putting this out there, I'm not sure if my interpretation is correct or not, but it makes sense in my head.  :)

Careful analysis of the images points to the hypothesis that there are two cycles going on here.  One is the automatic source cycle that varies the source strength based on time.  The other cycle is determined by varying the amplitudes of the sources as they are generated.

When the loop fades away entirely, that's the automatic cycle going to zero.  The current going around the ring is the amplitude cycle.  After the automatic cycle goes to zero, it starts going negative, which has the result of inverting the amplitude cycle.  This switches the blue half of the loop to red and the red to blue.  This can be seen by looking at hz-000000190.png, hz-000000200.png, and hz-000000210.png.  First the left is blue, then after it passes thru 0, it switches to red.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/04/2015 12:21 AM

Quote
The Casimir force arises as a result of a geometric conducting boundary in the form of two plates being placed in close proximity to one another such that the geometry of the cavity can preclude the ability for certain wavelengths of light from being present in one direction

In the current context:  :o :o 8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/04/2015 01:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422615#msg1422615">Quote from: aero on 09/03/2015 09:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422589#msg1422589">Quote from: X_RaY on 09/03/2015 08:10 PM</a>
@aero
Questions about your loop:
1) Is the length of the loop equal to 1lambda (it looks like that)?
2) Shows the visible pattern the H field component in the z direction? The file names suggest that...

I decided that we need to see more data. The previous movie was for a time slice every 10 computational cycles, every 10 time steps. I made a new run outputting the image at every time step. The image is of the z component of the magnetic field. The circumference of the loop is 3 wavelengths. That's just so the small images will show on my computer screen.

https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing)

The problem that I don't understand has to do with the cycling of the drive current. As it stands, the complete loop is regenerated at every time step so as the current in the loop reverses direction the complete loop current fades away as current passes through zero. But at the speed of the current and the very fine resolution of the simulation, is that what really happens? It takes 200 time steps for the curent to make a complete circut of the loop so how can the current at a point 100 time steps behind (half way around the loop) go to zero at the same time as the drive current?

Same thing at power on. The complete loop is excited at power on but shouldn't the points on the loop be excited in turn, one more point per time step (assuming the loop points are synchronized with speed of current)?

Well first, what exactly am I looking at.  In this one circle or a series of dipole antennas in a circle?  The problem seems to be, if I understand correctly, that a current should propagate around the circle at C.  You are seeing a bit of the circle that the current has not hit yet, respond to current located on the other side of the circle, i.e. responding faster than C if current travels the circumference of the circle but not faster than C if it travels the radius.  Am I describing this right? 

By any chance is this not actually a single circle but a series of antenna all receiving a signal split off the same central hub such that a signal travels from the hub to the antenna in such a way that it executes a preprogrammed  state before the light from the other antennas can reach it?  Because you are looking at it end on the individual antennas firing seem like something is traveling faster than the speed of light (much as I could attach two lightbulbs to atomic clocks, one in Chicago the other in Tokyo and preset them to light in sequence in less time than it would take light to travel between the two points).  That would be one of the classic, not really FTL but looks like it from a distance effects.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 02:09 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422615#msg1422615">Quote from: aero on 09/03/2015 09:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422589#msg1422589">Quote from: X_RaY on 09/03/2015 08:10 PM</a>
@aero
Questions about your loop:
1) Is the length of the loop equal to 1lambda (it looks like that)?
2) Shows the visible pattern the H field component in the z direction? The file names suggest that...

I decided that we need to see more data. The previous movie was for a time slice every 10 computational cycles, every 10 time steps. I made a new run outputting the image at every time step. The image is of the z component of the magnetic field. The circumference of the loop is 3 wavelengths. That's just so the small images will show on my computer screen.

https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tYjVwZzJzWk9wckE&usp=sharing)

The problem that I don't understand has to do with the cycling of the drive current. As it stands, the complete loop is regenerated at every time step so as the current in the loop reverses direction the complete loop current fades away as current passes through zero. But at the speed of the current and the very fine resolution of the simulation, is that what really happens? It takes 200 time steps for the curent to make a complete circut of the loop so how can the current at a point 100 time steps behind (half way around the loop) go to zero at the same time as the drive current?

Same thing at power on. The complete loop is excited at power on but shouldn't the points on the loop be excited in turn, one more point per time step (assuming the loop points are synchronized with speed of current)?

Couple questions
What frequency are you inserting into the loop?
0.36732 M? 2.45GHz?
What is the outer circumference of the loop any difference than inner?
How do you calculate the frequency for the snubs or the dipoles, you doing he same here??
It looks like you need to have a gap in the loop to be your insertion points as the loop looks solid. This is like a 1/4 wave snub with ends but in a loop.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 02:33 AM
Excitation frequency, 2.50 GHz. Length of the loop? Circumference is 3 wavelengths. Yes, hz.pngs
Same kind of dipoles as always with phase shifting. A gap will be simple to add but do we really need it in the numerical model?

You are looking at, in this case, a set of 360 point sources phased around the loop. Of course they turn on at the same time. My question may have been reverse logic but I really wanted someone to decide, "That's Ok or no, that's not good enough for what we need.

If it's good enough I can take out the phasing, then I have a circle made up of point sources that flash on and off with perfect symmetry always shining the EM fields axially in the cavity. But in the real situation the antenna pattern will be more like a search light searching around the axis of rotation (horizontal loop), not like a fixed search light pointing straight up.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 03:00 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422691#msg1422691">Quote from: aero on 09/04/2015 02:33 AM</a>
Excitation frequency, 2.50 GHz. Length of the loop? Circumference is 3 wavelengths. Yes, hz.pngs
Same kind of dipoles as always with phase shifting. A gap will be simple to add but do we really need it in the numerical model?

You are looking at, in this case, a set of 360 point sources phased around the loop. Of course they turn on at the same time. My question may have been reverse logic but I really wanted someone to decide, "That's Ok or no, that's not good enough for what we need.

If it's good enough I can take out the phasing, then I have a circle made up of point sources that flash on and off with perfect symmetry always shining the EM fields axially in the cavity. But in the real situation the antenna pattern will be more like a search light searching around the axis of rotation (horizontal loop), not like a fixed search light pointing straight up.

In the frustum you can throw out 1/4 or 1/2 wave making up the loop and make it 1/3 wavelength. You will get some interesting patterns.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 03:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422698#msg1422698">Quote from: SeeShells on 09/04/2015 03:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422691#msg1422691">Quote from: aero on 09/04/2015 02:33 AM</a>
Excitation frequency, 2.50 GHz. Length of the loop? Circumference is 3 wavelengths. Yes, hz.pngs
Same kind of dipoles as always with phase shifting. A gap will be simple to add but do we really need it in the numerical model?

You are looking at, in this case, a set of 360 point sources phased around the loop. Of course they turn on at the same time. My question may have been reverse logic but I really wanted someone to decide, "That's Ok or no, that's not good enough for what we need.

If it's good enough I can take out the phasing, then I have a circle made up of point sources that flash on and off with perfect symmetry always shining the EM fields axially in the cavity. But in the real situation the antenna pattern will be more like a search light searching around the axis of rotation (horizontal loop), not like a fixed search light pointing straight up.

In the frustum you can throw out 1/4 or 1/2 wave making up the loop and make it 1/3 wavelength. You will get some interesting patterns.

Shell

Shell - A little more specific here, please. What? are you talking about. the frustum length is 0.1634 meters, the loop doesn't have a length, it has a radius, a diameter and a circumference. Circumference is a parameter now but of course I could change that. So again, What?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 09/04/2015 04:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422637#msg1422637">Quote from: SeeShells on 09/03/2015 10:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422621#msg1422621">Quote from: Rodal on 09/03/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422613#msg1422613">Quote from: SeeShells on 09/03/2015 09:21 PM</a>
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum :)

I see that it has now been published in:

Journal of Modern Physics, 2015, 6, 1308-1320

One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it.  The paper intends to address the issue of inmutability and undegredability of the QV.  In Dr. White's  hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold. 


**************************************************

This is an open access peer-reviewed journal that has a

Google h5-index=13    h5-median   =19

https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy

(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.

Thanks for the reply, I had not seen it.

Shell

Those comparisons toward the end between the pressure waves in a ringing basketball and the hydrogen electron orbitals are...quite interesting.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 04:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422699#msg1422699">Quote from: aero on 09/04/2015 03:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422698#msg1422698">Quote from: SeeShells on 09/04/2015 03:00 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422691#msg1422691">Quote from: aero on 09/04/2015 02:33 AM</a>
Excitation frequency, 2.50 GHz. Length of the loop? Circumference is 3 wavelengths. Yes, hz.pngs
Same kind of dipoles as always with phase shifting. A gap will be simple to add but do we really need it in the numerical model?

You are looking at, in this case, a set of 360 point sources phased around the loop. Of course they turn on at the same time. My question may have been reverse logic but I really wanted someone to decide, "That's Ok or no, that's not good enough for what we need.

If it's good enough I can take out the phasing, then I have a circle made up of point sources that flash on and off with perfect symmetry always shining the EM fields axially in the cavity. But in the real situation the antenna pattern will be more like a search light searching around the axis of rotation (horizontal loop), not like a fixed search light pointing straight up.

In the frustum you can throw out 1/4 or 1/2 wave making up the loop and make it 1/3 wavelength. You will get some interesting patterns.

Shell

Shell - A little more specific here, please. What? are you talking about. the frustum length is 0.1634 meters, the loop doesn't have a length, it has a radius, a diameter and a circumference. Circumference is a parameter now but of course I could change that. So again, What?
Sorry to confuse you, I should have followed you more closely. I wanted you to do a 1/4 wave as it will be easier to see if you got it right with your simulation in meep.

For reference, The EW ( different frequency) loop was about 14mm diameter or 44mm in circumference or about a 1/3 wavelength, the difference between the circumference and the diameter is the gap for the input feeds. This is a magnetic loop which is a little different than a 1/4 wave dipole.

There are reasons for doing a loop antenna. The size of the loop will determine the Q of the cavity and right now it's a tough number to come up with calculating a magnetic loop inside a asymetrical copper cavity. The maximum diameter I would think we will model is 63.5mm but be prepared if this kills the cavity Q we will need to make it a little smaller.

So get this 1/4 wave running then we can take the next step.

Shell

ARRL loop caculator  http://www.66pacific.com/calculators/small_tx_loop_calc.aspx

 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 04:21 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422705#msg1422705">Quote from: Prunesquallor on 09/04/2015 04:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422637#msg1422637">Quote from: SeeShells on 09/03/2015 10:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422621#msg1422621">Quote from: Rodal on 09/03/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422613#msg1422613">Quote from: SeeShells on 09/03/2015 09:21 PM</a>
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum :)

I see that it has now been published in:

Journal of Modern Physics, 2015, 6, 1308-1320

One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it.  The paper intends to address the issue of inmutability and undegredability of the QV.  In Dr. White's  hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold. 


**************************************************

This is an open access peer-reviewed journal that has a

Google h5-index=13    h5-median   =19

https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy

(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.

Thanks for the reply, I had not seen it.

Shell

Those comparisons toward the end between the pressure waves in a ringing basketball and the hydrogen electron orbitals are...quite interesting.
I'm not quite sure if I follow what he is trying to say and I think I see it but I want to read it again. I do know new evidence is showing that the QV isn't as non-mutable as it was once seemed and can be something lower than zero.
(warning Clickbait) http://phys.org/news/2015-08-scientists-particle.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/04/2015 07:51 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422639#msg1422639">Quote from: Rodal on 09/03/2015 10:31 PM</a>
Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.

Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert.   Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum.  You are welcome to contact Prof. Woodward to find out whether my understanding is up to date (and if so, whether your understanding of his theory is being properly applied to an EM Drive without any dielectric insert).

The principle explored by Dr Woodward to induce Machian mass fluctuation must be distinguished from his particular engineering implementation which uses dielectric capacity to put the highest possible energy on accelerated matter. Woodward could well have used magnetic energy put in high permeability material. Moreover Woodward does not exclude the use of polarizable vacuum to play with this Machian mass fluctuation as he explains it in the following excerpt of his article "RAPID SPACETIME TRANSPORT AND MACHIAN MASS FLUCTUATIONS: THEORY AND EXPERIMENT "
 
Quote
"Should the relative phase of the mass fluctuation and the magnetic part of the Lorentz force be auspicious, a stationary force should result.  But such a force, if present, is a result of the mass fluctuation that arises from the inertial coupling of the constituents of the dielectric to the rest of the universe. It is not due to a local violation of the conservation of momentum in a purely electrodynamical system.  It is worth remarking that a stationary force in a system of this sort may be expected even if the “substance” between the plates of the capacitor is the vacuum.  If the charged particle pair production in the vacuum of quantum lore actually takes place, the pairs should experience the same effects as material dielectric media. So exploration of this sort of arrangement of circuit elements has scientific value (as a test of the “polarizable vacuum” conjecture), as well as potential technological implications."

The importance of harmonics generation is outlined in this other excerpt of the same article :
Quote
" For example, generation of the effect seems to depend quite critically on the production of higher harmonics in the PZT stacks, for sinking a lot of power into a stack at a mechanical resonance of the stack is not, itself, sufficient to yield an effect.  "

I give in the attachment the article of Woodward I refer to.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/04/2015 09:38 AM
Aero -

The Q value for rfmwguy's mesh frustrum seems to be of interest at the moment.

It was a while back, but if I recall correctly, you said that creating a MEEP control file for a mesh frustrum would be way too much effort.

It occurred to me yesterday that I may be able to compute and output a complex file using Excel if I knew the syntax required and it was reasonably tractable (and I could compute the position data for the holes!). Doubtless there are other ways, but this is one I'm familiar with.

I know the Q values from MEEP are somewhat controversial, but with the correct control files we might see how MEEP thinks Q would change when holes are added.

Anyway, I'm volunteering to help if this is something you want to have a look at.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 09/04/2015 09:39 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422707#msg1422707">Quote from: SeeShells on 09/04/2015 04:21 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422705#msg1422705">Quote from: Prunesquallor on 09/04/2015 04:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422637#msg1422637">Quote from: SeeShells on 09/03/2015 10:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422621#msg1422621">Quote from: Rodal on 09/03/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422613#msg1422613">Quote from: SeeShells on 09/03/2015 09:21 PM</a>
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum :)

I see that it has now been published in:

Journal of Modern Physics, 2015, 6, 1308-1320

One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it.  The paper intends to address the issue of inmutability and undegredability of the QV.  In Dr. White's  hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold. 


**************************************************

This is an open access peer-reviewed journal that has a

Google h5-index=13    h5-median   =19

https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy

(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.

Thanks for the reply, I had not seen it.

Shell

Those comparisons toward the end between the pressure waves in a ringing basketball and the hydrogen electron orbitals are...quite interesting.
I'm not quite sure if I follow what he is trying to say and I think I see it but I want to read it again. I do know new evidence is showing that the QV isn't as non-mutable as it was once seemed and can be something lower than zero.
(warning Clickbait) http://phys.org/news/2015-08-scientists-particle.html

I think the point is that wave-like behavior of the quantum vacuum could potentially explain things in the quantum world just as well as blind adherence to Schroedinger's equation.  And therefore could also give the EM-Drive something to "push against".  It's basically the Copenhagen vs the deBroglie-Bohm interpretations.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/04/2015 11:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422398#msg1422398">Quote from: cee on 09/03/2015 05:54 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1420761#msg1420761">Quote from: graybeardsyseng on 08/28/2015 07:18 PM</a>
I finally finished the loop antenna modeling exercise.  Not sure if this is still useful but I will post here.   Likely the patterns are the most useful part - as they should give some idea of what modes can be stimulated.   

These models and results are made using a version of the NEC codes (specifically EZNEC).  NEC antenna modeling is not perfect but if you stay within the constraints it can produce qualitatively useful results.   As with all such models, quantitative results are highly dependent on many factors including geometry, signal quality, and many more.   Hopefully these will be of use - particularly if the loops are in a spherical chicken in a vacuum.

I modeled three sizes of antenna 1/2, 1, and 2 wavelength circumference, at three different heights - 1/4, 1/2 and 1 wavelength.   Also modeled each of these configurations for loops both parallel to and normal to their ground plane.

Sorry for how long this took - as some of you know I have been in the process of retiring and unfortunately this exercise mostly had to take place late in evening after all other boring but necessary stuff had been done.  I am now free and hope to start detailed planning for my own DIY experiments soon.

Herman
Herman,
Here's a 4NEC2 file of a small loop, I ran cases for .36 inch dia and am posting the NASA 0.55 inch loop. They serve as an approximate starting point in free space, in a cavity the impedance will be reduced by the mirroring of the walls. Impedance is 133-j60 and SWR 3.28. You will have to rename the NEC file, replace dot with a period and delete txt. The images are bmp files, replace dot with a period and remove txt.

Cee - THANKS!   I will get to converting these and running ASAP - hopefully today or tomorrow.   This saves a bunch of time.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 12:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422774#msg1422774">Quote from: Prunesquallor on 09/04/2015 09:39 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422707#msg1422707">Quote from: SeeShells on 09/04/2015 04:21 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422705#msg1422705">Quote from: Prunesquallor on 09/04/2015 04:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422637#msg1422637">Quote from: SeeShells on 09/03/2015 10:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422621#msg1422621">Quote from: Rodal on 09/03/2015 09:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422613#msg1422613">Quote from: SeeShells on 09/03/2015 09:21 PM</a>
Everyone read this? From Eagle Works

http://www.scirp.org/Journal/PaperInformation.aspx?PaperID=59027
Yes, this paper was pre-announced by Paul March (who is one of the co-authors) pre-publication, who also shared it at publication time (as a NASA report), and discussed in previous threads with Paul March and others in the forum :)

I see that it has now been published in:

Journal of Modern Physics, 2015, 6, 1308-1320

One of the main purposes is to discuss Dr. White's hypothesis that there are different sub-levels to the Quantum Vacuum, and hence formally address the objection from some people that if the QV is the zero-point energy (as originally postulated by Einstein) then one should not be able to extract any energy from it.  The paper intends to address the issue of inmutability and undegredability of the QV.  In Dr. White's  hypothesis the QV needs to be mutable and degradable if his explanation for EM Drive thrust is to hold. 


**************************************************

This is an open access peer-reviewed journal that has a

Google h5-index=13    h5-median   =19

https://scholar.google.com/citations?view_op=top_venues&hl=en&vq=phy

(https://scholar.google.com/citations?hl=en&view_op=search_venues&vq=Journal+of+Modern+Physics)
Got to give them credit they are definitely trying to chip away at the QV immutability.

Thanks for the reply, I had not seen it.

Shell

Those comparisons toward the end between the pressure waves in a ringing basketball and the hydrogen electron orbitals are...quite interesting.
I'm not quite sure if I follow what he is trying to say and I think I see it but I want to read it again. I do know new evidence is showing that the QV isn't as non-mutable as it was once seemed and can be something lower than zero.
(warning Clickbait) http://phys.org/news/2015-08-scientists-particle.html

I think the point is that wave-like behavior of the quantum vacuum could potentially explain things in the quantum world just as well as blind adherence to Schroedinger's equation.  And therefore could also give the EM-Drive something to "push against".  It's basically the Copenhagen vs the deBroglie-Bohm interpretations.
You know what they say? Don't piss off the cat. ;)

As simple as make a bump in the QV and push against it, somehow it seems too simple and in other ways not so much.  I wish I had more hardcore data to attach to it.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/04/2015 02:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422768#msg1422768">Quote from: Mezzenile on 09/04/2015 07:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422639#msg1422639">Quote from: Rodal on 09/03/2015 10:31 PM</a>
Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.

Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert.   Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum.  You are welcome to contact Prof. Woodward to find out whether my understanding is up to date (and if so, whether your understanding of his theory is being properly applied to an EM Drive without any dielectric insert).

The principle explored by Dr Woodward to induce Machian mass fluctuation must be distinguished from his particular engineering implementation which uses dielectric capacity to put the highest possible energy on accelerated matter. Woodward could well have used magnetic energy put in high permeability material. Moreover Woodward does not exclude the use of polarizable vacuum to play with this Machian mass fluctuation as he explains it in the following excerpt of his article "RAPID SPACETIME TRANSPORT AND MACHIAN MASS FLUCTUATIONS: THEORY AND EXPERIMENT "
 
Quote
"Should the relative phase of the mass fluctuation and the magnetic part of the Lorentz force be auspicious, a stationary force should result.  But such a force, if present, is a result of the mass fluctuation that arises from the inertial coupling of the constituents of the dielectric to the rest of the universe. It is not due to a local violation of the conservation of momentum in a purely electrodynamical system.  It is worth remarking that a stationary force in a system of this sort may be expected even if the “substance” between the plates of the capacitor is the vacuum.  If the charged particle pair production in the vacuum of quantum lore actually takes place, the pairs should experience the same effects as material dielectric media. So exploration of this sort of arrangement of circuit elements has scientific value (as a test of the “polarizable vacuum” conjecture), as well as potential technological implications."

The importance of harmonics generation is outlined in this other excerpt of the same article :
Quote
" For example, generation of the effect seems to depend quite critically on the production of higher harmonics in the PZT stacks, for sinking a lot of power into a stack at a mechanical resonance of the stack is not, itself, sufficient to yield an effect.  "

I give in the attachment the article of Woodward I refer to.

Prof. Woodward, has been familiar with Shawyer's EM Drive for several years, as well as familiar with NASA Eagleworks experiments.  You are welcome to contact Prof. Woodward directly and verify Prof. Woodward's opinion, on whether he agrees with you that Woodward's theory can be used to justify any thrust as a means of space propulsion from Shawyer's closed cavity EM Drive without a dielectric insert:

http://physics.fullerton.edu/component/zoo/item/dr-james-f-woodward

To the extent that your interpretation of Woodward's theory differs from Woodward's conclusions regarding the ability of Shawyer's EM  Drive without a dielectric insert, then the theory becomes your theory and not Woodward's theory.  To the extent that your interpretation of Woodward's theory differs from Woodward's, it may be interesting to discuss in this thread: will you change Woodward's opinion regarding Shawyer's EM Drive without a dielectric insert?  will Woodward change your opinion?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Gravity on 09/04/2015 03:00 PM
hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves

http://jnaudin.free.fr/html/gravshld.htm

best regards
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/04/2015 03:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422885#msg1422885">Quote from: Gravity on 09/04/2015 03:00 PM</a>
hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves

http://jnaudin.free.fr/html/gravshld.htm

best regards
The experiment is performed in a garage and not in a vacuum.  As discussed numerous times in this thread and lately regarding RFMWGUY's experiments, magnetrons get hot and therefore produce lifting thermal currents due to natural convection.  Any such test should either be conducted in a vacuum or otherwise the thermal lifting forces should be properly accounted for and not ignored when claiming "lifting effects".

(christst.jpg)

(barbury2.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 09/04/2015 03:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422885#msg1422885">Quote from: Gravity on 09/04/2015 03:00 PM</a>
hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves

http://jnaudin.free.fr/html/gravshld.htm

best regards
Don't know about antigravity but sure admire the shop mechanics and workmanship. The wave generator appears to be a modified waveguide log spiral cavity that transitions the TE10 to a three way TE11 circular splitter that feeds three paralleled spherical resonators. A modeler's nightmare in any EM sim. Amazing what can be done with fiberglass,sheet metal  and aluminum foil, wonder how much more copper would have cost.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 04:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422773#msg1422773">Quote from: RERT on 09/04/2015 09:38 AM</a>
Aero -

The Q value for rfmwguy's mesh frustrum seems to be of interest at the moment.

It was a while back, but if I recall correctly, you said that creating a MEEP control file for a mesh frustrum would be way too much effort.

It occurred to me yesterday that I may be able to compute and output a complex file using Excel if I knew the syntax required and it was reasonably tractable (and I could compute the position data for the holes!). Doubtless there are other ways, but this is one I'm familiar with.

I know the Q values from MEEP are somewhat controversial, but with the correct control files we might see how MEEP thinks Q would change when holes are added.

Anyway, I'm volunteering to help if this is something you want to have a look at.

R.

That's a generous offer but I'm not sure how it could work. The syntax for meep geometry is here:
http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#geometric-object (http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#geometric-object)
As you can see, meep expects input geometry to be defined in the Scheme programming language. (Python and C++ interfaces are also available, but not on my system)

You can also load data into meep that has been saved in HDF5 format but that requires identical dimensions to the meep lattice and, well basically, the data file to have been generated by a prior meep run. Meep does not deal well with anything that is different than what it expects.

I think it would be more productive to learn to code control file geometry in Scheme. You could use the control file from the emdrive wiki and focus on coding the mesh into the existing geometry.

aero

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/04/2015 04:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422904#msg1422904">Quote from: cee on 09/04/2015 03:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422885#msg1422885">Quote from: Gravity on 09/04/2015 03:00 PM</a>
hello everybody!
do you know this work of Chris Hardeman in 2001 with microwaves

http://jnaudin.free.fr/html/gravshld.htm

best regards
Don't know about antigravity but sure admire the shop mechanics and workmanship. The wave generator appears to be a modified waveguide log spiral cavity that transitions the TE10 to a three way TE11 circular splitter that feeds three paralleled spherical resonators. A modeler's nightmare in any EM sim. Amazing what can be done with fiberglass,sheet metal  and aluminum foil, wonder how much more copper would have cost.

I also note that while the author of the experiment wrote:

Quote
Buoyancy and thermal interference's can be ruled out as the cause of the effects as the device never gets hot.

He did not report measurements of the magnetron's temperature, unlike RFMWGUY who carefully measured and reported the magnetron's temperature.

Furthermore I note that none of the links to the author in  http://nexusilluminati.blogspot.com/2011/11/gravity-shielding-experiment.html are still active.  All these links are no longer active:

http://users.icnet.net/~chrish/Post_tests.htm

etc.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 04:51 PM
Would someone please make a movie of this loop antenna?

https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing)

The drive frequency is 2.47 GHz, loop circumference is 1 wave length and the run is for 3 cycles with 20 png's output per cycle.

It looks good to me. That doesn't mean that it will do what we expect but it is a start.

Now, if SeeShells will only tell me, in English, what it is that she is measuring with 1/4, 1/2 and 1/3 wavelength then I would make some test runs. :)

But I think I will go this way.

All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in wave lengths of the drive center frequency. The drive center frequency must also be specified. The x, y and z coordinate location of the center of the loop must also be specified in wavelengths  and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.

This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation.

Again, all dimensions must be specified in wave lengths, or a fraction of, or a rational fraction of wavelengths.


OK - This specification requirement to use wavelength is NULL AND VOID. Use meters instead. See my post on page 84. Problem is that wavelength changes with frequency, so the geometry changes and like a dog chasing his tail, that doesn't work when making resonance runs to find the frequency of resonance.

The loop can be tipped off horizontal up to 90 degrees rotation about the y axis. Tipping the loop about the x axis is not implemented.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 09/04/2015 04:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926">Quote from: aero on 09/04/2015 04:51 PM</a>
Would someone please make a movie of this loop antenna?

https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing)

...


I'll do it tonight (I get home at 9PM EDT) if nobody does it first...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/04/2015 05:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926">Quote from: aero on 09/04/2015 04:51 PM</a>
Would someone please make a movie of this loop antenna?

https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing)

The drive frequency is 2.47 GHz, loop circumference is 1 wave length and the run is for 3 cycles with 20 png's output per cycle.

It looks good to me. That doesn't mean that it will do what we expect but it is a start.

Now, if SeeShells will only tell me, in English, what it is that she is measuring with 1/4, 1/2 and 1/3 wavelength then I would make some test runs. :)

But I think I will go this way.

All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in wave lengths of the drive center frequency. The drive center frequency must also be specified. The x, y and z coordinate location of the center of the loop must also be specified in wavelengths  and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.

This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation.

Again, all dimensions must be specified in wave lengths, or a fraction of, or a rational fraction of wavelengths.


The loop can be tipped off horizontal up to 90 degrees rotation about the y axis. Tipping the loop about the x axis is not implemented.
Whatever you have changed this looks much more natural than the last try.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/04/2015 05:10 PM
Stupid question but, is there anything in a magnetron housing that might provide some current to the magnetron from a themoelectric effect after power off?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 05:14 PM
I'll do a detailed spec after I get back from an errand.
Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/04/2015 06:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422932#msg1422932">Quote from: X_RaY on 09/04/2015 05:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926">Quote from: aero on 09/04/2015 04:51 PM</a>
Would someone please make a movie of this loop antenna?

https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tdlZwUGI3NGc4eXc&usp=sharing)

The drive frequency is 2.47 GHz, loop circumference is 1 wave length and the run is for 3 cycles with 20 png's output per cycle.

It looks good to me. That doesn't mean that it will do what we expect but it is a start.

Now, if SeeShells will only tell me, in English, what it is that she is measuring with 1/4, 1/2 and 1/3 wavelength then I would make some test runs. :)

But I think I will go this way.

All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in wave lengths of the drive center frequency. The drive center frequency must also be specified. The x, y and z coordinate location of the center of the loop must also be specified in wavelengths  and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.

This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation.

Again, all dimensions must be specified in wave lengths, or a fraction of, or a rational fraction of wavelengths.


The loop can be tipped off horizontal up to 90 degrees rotation about the y axis. Tipping the loop about the x axis is not implemented.
Whatever you have changed this looks much more natural than the last try.
@aero
Can you try either a run with the same frequency but 2 times the actual circumference, or two times the frequency of the last run?
The background is that in such a test there has to be two more nodes along the circumference. That would be a simple way to test your code.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 07:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422956#msg1422956">Quote from: X_RaY on 09/04/2015 06:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422932#msg1422932">Quote from: X_RaY on 09/04/2015 05:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926">Quote from: aero on 09/04/2015 04:51 PM</a>

                            ... snip ...

Whatever you have changed this looks much more natural than the last try.
@aero
Can you try either a run with the same frequency but 2 times the actual circumference, or two times the frequency of the last run?
The background is that in such a test there has to be two more nodes along the circumference. That would be a simple way to test your code.

Yes, I made that run - see attached. I did run it with circumference of 3 wave lengths also but I neglected to save that data set. It looked right though with 6 nodes along the circumference.

These are point sources distributed around in a loop and turned on in sequence synchronized with meep-time. Sequencing the turn-on, as lmbfan pointed out, maintains the phasing around the loop. Thanks lmbfan. So I don't need to fool with manually phasing the source with amplitude. It is much less complex.

It seems that meep will not do a dipole source at arbitrary angles to the primary axis so I'm forced to use point sources. There are no sequenced dipoles, and seemingly no support in meep for that except parallel to primary axis.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 09/04/2015 07:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422768#msg1422768">Quote from: Mezzenile on 09/04/2015 07:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422639#msg1422639">Quote from: Rodal on 09/03/2015 10:31 PM</a>
Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.

Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert.   Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum.  You are welcome to contact Prof. Woodward to find out whether my understanding is up to date (and if so, whether your understanding of his theory is being properly applied to an EM Drive without any dielectric insert).

The principle explored by Dr Woodward to induce Machian mass fluctuation must be distinguished from his particular engineering implementation which uses dielectric capacity to put the highest possible energy on accelerated matter. Woodward could well have used magnetic energy put in high permeability material. Moreover Woodward does not exclude the use of polarizable vacuum to play with this Machian mass fluctuation as he explains it in the following excerpt of his article "RAPID SPACETIME TRANSPORT AND MACHIAN MASS FLUCTUATIONS: THEORY AND EXPERIMENT "
 
Quote
"Should the relative phase of the mass fluctuation and the magnetic part of the Lorentz force be auspicious, a stationary force should result.  But such a force, if present, is a result of the mass fluctuation that arises from the inertial coupling of the constituents of the dielectric to the rest of the universe. It is not due to a local violation of the conservation of momentum in a purely electrodynamical system.  It is worth remarking that a stationary force in a system of this sort may be expected even if the “substance” between the plates of the capacitor is the vacuum.  If the charged particle pair production in the vacuum of quantum lore actually takes place, the pairs should experience the same effects as material dielectric media. So exploration of this sort of arrangement of circuit elements has scientific value (as a test of the “polarizable vacuum” conjecture), as well as potential technological implications."

The importance of harmonics generation is outlined in this other excerpt of the same article :
Quote
" For example, generation of the effect seems to depend quite critically on the production of higher harmonics in the PZT stacks, for sinking a lot of power into a stack at a mechanical resonance of the stack is not, itself, sufficient to yield an effect.  "

I give in the attachment the article of Woodward I refer to.

The text by Woodward you refer to was cowritten with Paul March:

Woodward, James F.; Mahood, Thomas L.; March, Paul (July 2001). "Rapid Spacetime Transport and Machian Mass Fluctuations: Theory and Experiment" (http://physics.fullerton.edu/~jimw/Jpcawf1.pdf). JPC 2001 Proceedings. 37th AIAA/ASME Joint Propulsion Conference, Salt Lake City, Utah. American Institute of Aeronautics and Astronautics. doi:10.2514/6.2001-3907

Most importantly, it was written in 2001, while Puthof's Polarizable Vacuum theory was only a few months old. Nowadays Woodward does not think PV is realistic anymore, nor any ZPF theory (including McCulloch's MiHsC or White's QVF conjecture) to explain Mach effects. He is very clear about that when asked on that matter.
 
Woodward is even currently writing a paper demonstrating why virtual particles of the vacuum can not be used for propulsion.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/04/2015 07:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422975#msg1422975">Quote from: aero on 09/04/2015 07:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422956#msg1422956">Quote from: X_RaY on 09/04/2015 06:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422932#msg1422932">Quote from: X_RaY on 09/04/2015 05:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926">Quote from: aero on 09/04/2015 04:51 PM</a>

                            ... snip ...

Whatever you have changed this looks much more natural than the last try.
@aero
Can you try either a run with the same frequency but 2 times the actual circumference, or two times the frequency of the last run?
The background is that in such a test there has to be two more nodes along the circumference. That would be a simple way to test your code.

Yes, I made that run - see attached. I did run it with circumference of 3 wave lengths also but I neglected to save that data set. It looked right though with 6 nodes along the circumference.

These are point sources distributed around in a loop and turned on in sequence synchronized with meep-time. Sequencing the turn-on, as lmbfan pointed out, maintains the phasing around the loop. Thanks lmbfan. So I don't need to fool with manually phasing the source with amplitude. It is much less complex.

It seems that meep will not do a dipole source at arbitrary angles to the primary axis so I'm forced to use point sources. There are no sequenced dipoles, and seemingly no support in meep for that except parallel to primary axis.
Go on this way, it looks right :)
The smaller antenna with lambda/4 for Shell will excite the TE012 for sure if you place it symmetrically around the middle axis. Dont ask me at what hight/ distance to the end plate ( ~Lambda/4 could work?*). The loop will be verry small but first don't worry about that (Rodal pointed this out some pages ago...).
Good luck for your next runs!

* Why lambda/4 ? : The wave will travel that way(90°) to the plate, than while the reflection the wave undergoes and shifts 180°, after that the wave travels back in the antenna direction(90°).
All that together gives one full wavelength and there will be constructive interference at the antenna location in the direction to the other plate.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 08:12 PM

Quote
The smaller antenna

Are you referring to the antenna with circumference of 1 wavelength?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/04/2015 08:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422985#msg1422985">Quote from: aero on 09/04/2015 08:12 PM</a>
Quote
The smaller antenna

Are you referring to the antenna with circumference of 1 wavelength?
No. Circumference Lambda/4 (or Lambda/3 like Shell said).

EDIT: The blue and red regions in your simulations corresponds to the direction of the H field (remember it's the Hz component). The TE01p mode is high symmetrically at each point around a single circumference, around the middle axis. The full loop has to have only one color for a ~half wavelength ( complete red, after that complete blue and so on) for this type of mode.

At least i am not 100 percent sure with that. Please try it. May be i am wrong  :-\ . At this point your help with the simulations is so important!!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 09:01 PM
An artefact of my implementation is that as the loop gets smaller the number of point sources making up the loop are reduced.  It is still one point for every meep time step but it takes a lot fewer time steps to walk around the smaller loop. I don't know if that will have an adverse effect or not. It does affect the amplitude of the signal.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/04/2015 09:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422996#msg1422996">Quote from: aero on 09/04/2015 09:01 PM</a>
An artefact of my implementation is that as the loop gets smaller the number of point sources making up the loop are reduced.  It is still one point for every meep time step but it takes a lot fewer time steps to walk around the smaller loop. I don't know if that will have an adverse effect or not. It does affect the amplitude of the signal.
Yes smaller loops gives lower amplitudes(also true in the real world, lower coupling...), but the wrong pattern at the loop could lead to a wrong field pattern means wrong mode..

On the other hand (for most geometries of such a resonator) there is only one mode possible, theoretically.

I don't believe that this is an artefact, half the number of points means you will see only one color for each half cycle. (Is that right??)
How it looks like for a lambda/4 circumference of the loop? Can you upload one or two full cycles? Myself or someone else will make a gif based on it :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/04/2015 10:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423000#msg1423000">Quote from: X_RaY on 09/04/2015 09:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422996#msg1422996">Quote from: aero on 09/04/2015 09:01 PM</a>
An artefact of my implementation is that as the loop gets smaller the number of point sources making up the loop are reduced.  It is still one point for every meep time step but it takes a lot fewer time steps to walk around the smaller loop. I don't know if that will have an adverse effect or not. It does affect the amplitude of the signal.
Yes smaller loops gives lower amplitudes(also true in the real world, lower coupling...), but the wrong pattern at the loop could lead to a wrong field pattern means wrong mode..

On the other hand (for most geometries of such a resonator) there is only one mode possible, theoretically.

I don't believe that this is an artefact, half the number of points means you will see only one color for each half cycle. (Is that right??)
How it looks like for a lambda/4 circumference of the loop? Can you upload one or two full cycles? Myself or someone else will make a gif based on it :)
In for a minute then have to dash off. A friend needs a lift her car broke down.

The wavelength of 2.5GHz (resonate frequency determined by harmiv and meep) for CE is 120mm. So, you want to try a lambda /4 of 30mm of loop circumference?  Direct multiples of the wavelength  1/2, 1/4, 1/8... will lead to excitement of other TMxx modes I do believe instead of the TExx That's why I was thinking of a 1/3 mode. But, we are in uncharted territory and aero is in the drivers seat. Speaking of driving... got to go. BBL.

Shell

PS: The wire faraday cage looks and tests out very well! I will be working late tonight it seems....

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/04/2015 10:48 PM
I've been making resonance runs for this antenna with the circumferences mentioned and see two interesting differences in the numbers from the dipole antennas used previously.

First though, the resonant frequency seems to be the same 2.50 GHz calculated before. More exactly, this

2.50021516E+009,
2.49990486E+009,
2.49989601E+009

for three runs.

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?

2 ) And this is interesting. When the drive frequency is less than the resonance frequency, Q does not suffer very much (20%) but the imaginary part of the complex amplitude is huge compared to the real part. This characteristic goes away when driving the cavity at the Harminv calculated resonant frequency. I don't recall what this means but I think I recall that the large imaginary component was related to something important. Dispersion, maybe?

Anyway, I can organize and post those numbers if there is interest.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/05/2015 12:06 AM
New meep simulations source link, below.

I've shared my folder meeper-files, which is laid out as follows:

meeper-files/
   CE2-0009-150904/                                             - all files associated with this run in this folder
      cvs-directory/                                                   - the cvs files from the Continuous run
          400+ files
      CE2-8Ey-dual_dipoles-250-csv.log                     - log file from running CE2-csv.sh
      CE2-dual_dipoles-250res.ctl                              - control file for the Continuous run at 250 resolution
      CE2-dual_dipoles-C-250res.log                          - log file from Continuous run
      CE2-dual_dipoles-G.ctl                                      - control file for the Gaussian run at 100 resolution
      CE2-dual_dipoles-G.log                                     - log file from Gaussian run
      meep-data-description-CE-2r9-32cy.txt             - my take at the data description file
  scripts/
      CE2-csv.sh                                                       - my current version of the parameterized script file

Note that in the future, there will be better agreement between run names (CE2r9), directory names (CE2-0009-150904), control file names (CE2-dual_dipoles-xxx), and log file names.  Sorry about that - it's been an evolution.  I can recreate the files with the CE2-0009 common prefix, if you'd like.

Link to meeper-files folder is https://drive.google.com/folderview?id=0B527OOY4hxdZfldTN2FoVm5SRDZ2MHFJYmhaM2ZFcXVEeklpd3NnTy1RUUtnS3d1YllCWGc&usp=sharing

Folder is shared public for viewing only.

Hope you'll find them useful.

Edit - correct root folder name to meeper-files.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 12:41 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
I've been making resonance runs for this antenna with the circumferences mentioned and see two interesting differences in the numbers from the dipole antennas used previously.

First though, the resonant frequency seems to be the same 2.50 GHz calculated before. More exactly, this

2.50021516E+009,
2.49990486E+009,
2.49989601E+009

for three runs.

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?

2 ) And this is interesting. When the drive frequency is less than the resonance frequency, Q does not suffer very much (20%) but the imaginary part of the complex amplitude is huge compared to the real part. This characteristic goes away when driving the cavity at the Harminv calculated resonant frequency. I don't recall what this means but I think I recall that the large imaginary component was related to something important. Dispersion, maybe?

Anyway, I can organize and post those numbers if there is interest.

Several things appear problematic above.  Since I'm short of time, I'll just pick this one:

<<When the drive frequency is less than the resonance frequency, Q does not suffer very much (20%) but the imaginary part of the complex amplitude is huge compared to the real part.>>

This appears contradictory, because Q is calculated by Harminv and only by Harminv.  It is calculated by Harminv as the half ratio of the real part to the imaginary part of the frequency, so if the imaginary part would increase by a "huge" amount with respect to the real real part of the frequency, then the calculated Q by Harminv should decrease in ("huge") inverse proportion to the huge increase in  the imaginary part of the frequency.

How can one divorce the calculated Q from the imaginary frequency, when the Q is calculated based on the ratio of the real to the imaginary parts of the frequency?

The calculated Q is conjoined with the ratio of the real part to the imaginary part of the frequency.  It does not make sense that these conjoined twins would be separated all of a sudden.

Only you have seen the Q and the real and imaginary parts of the frequency you are mentioning, but since you are posting, I guess that you were looking for some comment.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 12:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
...

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/05/2015 02:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423038#msg1423038">Quote from: Rodal on 09/05/2015 12:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
...

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?

I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.

Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 02:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423041#msg1423041">Quote from: aero on 09/05/2015 02:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423038#msg1423038">Quote from: Rodal on 09/05/2015 12:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
...

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?

I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.

Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.

So, if you used only one component before, why use 3 components now?

I can see using 2 components for a circle instead of 1 component for a straight dipole aligned along one of the Cartesian axes.  To define a component at an angle to the Cartesian axes you need the 2 components in the plane of the circle, but I have no idea as to why you are using a 3rd component, which is perpendicular to that plane.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/05/2015 02:20 AM
Purely as a practical matter, what would be the effect of putting an unpowered dipole at the center of the circle so that this could be fired in lower Q but interesting circle mode or higher Q but not TE12 central antenna mode?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 09/05/2015 02:21 AM
http://arxiv.org/abs/0810.2136

http://arxiv.org/pdf/1501.04586

http://arxiv.org/pdf/1507.01807


Interesting articles.

It's about  "Hall effect of light", berry phases, lorentz boost, and "anomalous velocity drift"
A little of "PT symmetry breaking" to force a prevalence of a determined helical mode, and perhaps a "thrust" may be explained.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/05/2015 03:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423044#msg1423044">Quote from: Rodal on 09/05/2015 02:13 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423041#msg1423041">Quote from: aero on 09/05/2015 02:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423038#msg1423038">Quote from: Rodal on 09/05/2015 12:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
...

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?

I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.

Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.

So, if you used only one component before, why use 3 components now?

I can see using 2 components for a circle instead of 1 component for a straight dipole aligned along one of the Cartesian axes.  To define a component at an angle to the Cartesian axes you need the 2 components in the plane of the circle, but I have no idea as to why you are using a 3rd component, which is perpendicular to that plane.

Well, no better idea, and anyway that was left over from debugging. Both TE and TM have 3 components, that's why the capability is built in. I have done as you suggested and am now making a run with only Ex and Ey excitation. Those two components are in the TE mode which is what I am hoping to excite.

I did change the Harminv detection location and component to Ey located 1/4 wavelength from the small end and maybe 70% toward the wall from the zero axis. It has been very near the center of the cavity. (Where is the best place to locate the detector?) This change increased the calculated Q to 7800 which is up from 3722.  That is of course another indication of the futility of trying to adjust the copper model to get realistic calculated Q values. The calculated Q depends on several seemingly extraneous parameters not related to the material model.

Ok - run finished -  exciting with only Ex and Ey reduced Q to 6661 and reduced the detected resonant frequency by 10 kHz. And in case I didn't mention it, this is with a 1/4 wave length circumference loop, 1/4 wavelength from the big end and centered.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/05/2015 03:27 AM
Will you guys slow down!  ;) I'm on a short vacation away from the interwebs and man, its a lot of work to catch up with the conversation...actually, I'm happy to see the work-flow continue. - From steamy central Indiana for a couple of more days.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/05/2015 06:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423059#msg1423059">Quote from: aero on 09/05/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423044#msg1423044">Quote from: Rodal on 09/05/2015 02:13 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423041#msg1423041">Quote from: aero on 09/05/2015 02:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423038#msg1423038">Quote from: Rodal on 09/05/2015 12:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
...

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?

I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.

Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.

So, if you used only one component before, why use 3 components now?

I can see using 2 components for a circle instead of 1 component for a straight dipole aligned along one of the Cartesian axes.  To define a component at an angle to the Cartesian axes you need the 2 components in the plane of the circle, but I have no idea as to why you are using a 3rd component, which is perpendicular to that plane.

Well, no better idea, and anyway that was left over from debugging. Both TE and TM have 3 components, that's why the capability is built in. I have done as you suggested and am now making a run with only Ex and Ey excitation. Those two components are in the TE mode which is what I am hoping to excite.

I did change the Harminv detection location and component to Ey located 1/4 wavelength from the small end and maybe 70% toward the wall from the zero axis. It has been very near the center of the cavity. (Where is the best place to locate the detector?) This change increased the calculated Q to 7800 which is up from 3722.  That is of course another indication of the futility of trying to adjust the copper model to get realistic calculated Q values. The calculated Q depends on several seemingly extraneous parameters not related to the material model.

Ok - run finished -  exciting with only Ex and Ey reduced Q to 6661 and reduced the detected resonant frequency by 10 kHz. And in case I didn't mention it, this is with a 1/4 wave length circumference loop, 1/4 wavelength from the big end and centered.

Try to use a H(z) component detector (if possible) at or close too the central axis, lambda/4 distance to the smaller end of the frustum. The magnetic field of TE012 would be strongest there.
For that mode Ex,Ey,Ez at the central axis and lambda/4 away from the plate are negligible/ very small.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/05/2015 07:24 AM

Quote from: flux_capacitor link=topic=38203.msg1422976#msg1422976 date=1441395215
[hr
The text by Woodward you refer to was cowritten with Paul March:
Woodward, James F.; Mahood, Thomas L.; March, Paul (July 2001). "Rapid Spacetime Transport and Machian Mass Fluctuations: Theory and Experiment" (http://physics.fullerton.edu/~jimw/Jpcawf1.pdf). JPC 2001 Proceedings. 37th AIAA/ASME Joint Propulsion Conference, Salt Lake City, Utah. American Institute of Aeronautics and Astronautics. doi:10.2514/6.2001-3907

Most importantly, it was written in 2001, while Puthof's Polarizable Vacuum theory was only a few months old. Nowadays Woodward does not think PV is realistic anymore, nor any ZPF theory (including McCulloch's MiHsC or White's QVF conjecture) to explain Mach effects. He is very clear about that when asked on that matter.
 
Woodward is even currently writing a paper demonstrating why virtual particles of the vacuum can not be used for propulsion.
Sorry for the missing of the other authors of the article but as you have seen in the version retrieved on the WEB and that I have attached in my previous post, Woodward was the only cited author.
The fact that March is a co-author of this article is interesting as he is himself willing to found an explanation of the Shawyer's EMDrive in term of Woodward's work:
http://nextbigfuture.com/2009/09/mach-effect-interview-with-paul-march.html (http://nextbigfuture.com/2009/09/mach-effect-interview-with-paul-march.html)
Quote
Question: "What do you think of the EMdrive work?"
March's answer: The proposed E&M/SRT conjecture IMO is garbage. The experimental results is tantalizing, but it has to be repeated in a vacuum chamber to get rid of possible spurious error sources for the thrust signatures observed. If it still moves in a 1x10-4 Torr vacuum, then we have to explain what is going on in view of Jim's work.

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/05/2015 07:58 AM
An article of this year on the  Biefeld-Brown effect : "On the Anomalous Weight Losses of High Voltage Symmetrical Capacitors" : http://arxiv.org/pdf/1502.06915.pdf (http://arxiv.org/pdf/1502.06915.pdf)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 10:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423059#msg1423059">Quote from: aero on 09/05/2015 03:20 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423044#msg1423044">Quote from: Rodal on 09/05/2015 02:13 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423041#msg1423041">Quote from: aero on 09/05/2015 02:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423038#msg1423038">Quote from: Rodal on 09/05/2015 12:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423021#msg1423021">Quote from: aero on 09/04/2015 10:48 PM</a>
...

1 ) The calculated quality factor is much lower whether excited by a magnetic or an electric source. Now, I am using all three components to excite the cavity (Ex, Ey, Ex) or (Hx, Hy, Hz) and maybe this is wrong. Does anyone know?...
What component(s) were you using for the straight dipole antenna you used to excite TM modes in the initial runs?

I used each of them but only one at a time. A single component exciting the cavity for each of 6 runs. All 6 Q values were higher than the Q I'm getting with the loop. One by only a small factor (1.5) and the rest by orders of magnitude. It may be that I am not detecting the right mode, using Hx and keep forgetting to change it. Hx is a TM mode component. But without your question, that possibility wouldn't have occurred to me for days. I'll check now.

Regarding the huge Imaginary component, I'm talking about amplitude, not frequency. I agree, for frequency that couldn't happen.

So, if you used only one component before, why use 3 components now?

I can see using 2 components for a circle instead of 1 component for a straight dipole aligned along one of the Cartesian axes.  To define a component at an angle to the Cartesian axes you need the 2 components in the plane of the circle, but I have no idea as to why you are using a 3rd component, which is perpendicular to that plane.

Well, no better idea, and anyway that was left over from debugging. Both TE and TM have 3 components, that's why the capability is built in. I have done as you suggested and am now making a run with only Ex and Ey excitation. Those two components are in the TE mode which is what I am hoping to excite.

I did change the Harminv detection location and component to Ey located 1/4 wavelength from the small end and maybe 70% toward the wall from the zero axis. It has been very near the center of the cavity. (Where is the best place to locate the detector?) This change increased the calculated Q to 7800 which is up from 3722.  That is of course another indication of the futility of trying to adjust the copper model to get realistic calculated Q values. The calculated Q depends on several seemingly extraneous parameters not related to the material model.

Ok - run finished -  exciting with only Ex and Ey reduced Q to 6661 and reduced the detected resonant frequency by 10 kHz. And in case I didn't mention it, this is with a 1/4 wave length circumference loop, 1/4 wavelength from the big end and centered.

A Q of 7800 with the Drude model constants you are using means that the cavity is NOT resonating much, as Meep resonance with this Drude model in the past has given Q's of millions (when the actual Q should have been in the tens of thousands).

What is the diameter of the loop you are using (diameter in meters) and what is the diameter of the cone at the location of your loop?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 12:21 PM
Trying to put more time into the build as I'm getting in the final hardware. Should have the waveguide to coax in today and splitters. Different laptop arriving today also that needs to be setup, the old one never did work and had to fight to get a refund, thank goodness I've been an ebayier for 14 years and have a good record.

Worked on the lasers yesterday getting the pinhole lens to work and tested the Faraday cage with the access ports for the beam, did very well. Laid out the ceramics for drilling for the center quartz rod today. Figured out the mounting for the first surface mirrors and got the hardware around to place them. Plus a bazzilion other things in verifying and profiling the test rig.

A good friend sent me a picture of a eco friendly wood power frustum, aero would you like to run this in your meep?

Will have drawings for you in a bit aero, less confusion with them I think.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/05/2015 01:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423032#msg1423032">Quote from: Eer on 09/05/2015 12:06 AM</a>
New meep simulations source link, below.

I've shared my folder meeper-files, which is laid out as follows:

meeper-files/
   CE2-0009-150904/                                             - all files associated with this run in this folder
      cvs-directory/                                                   - the cvs files from the Continuous run
          400+ files
      CE2-8Ey-dual_dipoles-250-csv.log                     - log file from running CE2-csv.sh
      CE2-dual_dipoles-250res.ctl                              - control file for the Continuous run at 250 resolution
      CE2-dual_dipoles-C-250res.log                          - log file from Continuous run
      CE2-dual_dipoles-G.ctl                                      - control file for the Gaussian run at 100 resolution
      CE2-dual_dipoles-G.log                                     - log file from Gaussian run
      meep-data-description-CE-2r9-32cy.txt             - my take at the data description file
  scripts/
      CE2-csv.sh                                                       - my current version of the parameterized script file

Note that in the future, there will be better agreement between run names (CE2r9), directory names (CE2-0009-150904), control file names (CE2-dual_dipoles-xxx), and log file names.  Sorry about that - it's been an evolution.  I can recreate the files with the CE2-0009 common prefix, if you'd like.

Link to meeper-files folder is https://drive.google.com/folderview?id=0B527OOY4hxdZfldTN2FoVm5SRDZ2MHFJYmhaM2ZFcXVEeklpd3NnTy1RUUtnS3d1YllCWGc&usp=sharing

Folder is shared public for viewing only.

Hope you'll find them useful.

Edit - correct root folder name to meeper-files.

I've added a png-directory to meeper-files/CE2-0009-150904 containing contour maps for each of the csv files. 

A word about scaling - these png files are each autoscaled.  I understand that may not be what we want.

I'm willing to work with folks who care to create png files that are scaled the way you want them, and to figure out how to automate the process.  There are two obvious choices - which is preferred?

1) autoscale each file, so differences in levels are clearly visible
2) fixed scale applied to all png files, so they can be readily and easily compared one to another.  This could mean that some files show very faint contours, if their range is much smaller than the fixed scale.

In the fixed scale choice, how would you like me to pick the scale?  The matplotlib library function contourf (which is what I'm using, so the images are filled, as opposed to just lines) can take an array of values for which contour lines should be generated - my question is:  how should I pick or generate that array of values?

Thanks,

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 09/05/2015 01:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423114#msg1423114">Quote from: SeeShells on 09/05/2015 12:21 PM</a>
Trying to put more time into the build as I'm getting in the final hardware. Should have the waveguide to coax in today and splitters. Different laptop arriving today also that needs to be setup, the old one never did work and had to fight to get a refund, thank goodness I've been an ebayier for 14 years and have a good record.

Worked on the lasers yesterday getting the pinhole lens to work and tested the Faraday cage with the access ports for the beam, did very well. Laid out the ceramics for drilling for the center quartz rod today. Figured out the mounting for the first surface mirrors and got the hardware around to place them. Plus a bazzilion other things in verifying and profiling the test rig.

A good friend sent me a picture of a eco friendly wood power frustum, aero would you like to run this in your meep?

Will have drawings for you in a bit aero, less confusion with them I think.

Shell

Is that an IR injecting waveguide coming in from the bottom? ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 02:06 PM
The smaller end of the frustum tends to correlate very well to the mode TE012 sizing in  position to the magnetic fields. I scaled a simulation of the magnetic fields and dropped them into a 3D model of the CE frustum and this is what looks like. The placement into the smaller end goes against the wisdom of 1/4 wavelengths in a dipole TExx mode to place it into the larger end but we are exciting a TE mode exciting the magnetic fields with the loop more like a coil winding.

If aero want to excite this configuration it would mirror what X_Ray was thinking in coupling to the modes. butttttt...
I think we are going to have to go to a dual loop placement into the mode shapes using a smaller loop in the smaller end of the cavity with phasing shifted to match the mode magnetic field direction to get a real stable TE012 and I'm working on the drawing and calculations to do just that.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/05/2015 02:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423127#msg1423127">Quote from: SeeShells on 09/05/2015 02:06 PM</a>
The smaller end of the frustum tends to correlate very well to the mode TE012 sizing in  position to the magnetic fields. I scaled a simulation of the magnetic fields and dropped them into a 3D model of the CE frustum and this is what looks like. The placement into the smaller end goes against the wisdom of 1/4 wavelengths in a dipole TExx mode to place it into the larger end but we are exciting a TE mode exciting the magnetic fields with the loop more like a coil winding.

If aero want to excite this configuration it would mirror what X_Ray was thinking in coupling to the modes. butttttt...
I think we are going to have to go to a dual loop placement into the mode shapes using a smaller loop in the smaller end of the cavity with phasing shifted to match the mode magnetic field direction to get a real stable TE012 and I'm working on the drawing and calculations to do just that.

Shell
The Lambda/4 loop seems too tiny while looking at the field configuration. Your 3 Lambda design may work, we will see :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 03:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423132#msg1423132">Quote from: X_RaY on 09/05/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423127#msg1423127">Quote from: SeeShells on 09/05/2015 02:06 PM</a>
The smaller end of the frustum tends to correlate very well to the mode TE012 sizing in  position to the magnetic fields. I scaled a simulation of the magnetic fields and dropped them into a 3D model of the CE frustum and this is what looks like. The placement into the smaller end goes against the wisdom of 1/4 wavelengths in a dipole TExx mode to place it into the larger end but we are exciting a TE mode exciting the magnetic fields with the loop more like a coil winding.

If aero want to excite this configuration it would mirror what X_Ray was thinking in coupling to the modes. butttttt...
I think we are going to have to go to a dual loop placement into the mode shapes using a smaller loop in the smaller end of the cavity with phasing shifted to match the mode magnetic field direction to get a real stable TE012 and I'm working on the drawing and calculations to do just that.

Shell
The Lambda/4 loop seems too tiny while looking at the field configuration. Your 3 Lambda design may work, we will see :)
It is a tiny lambda/4 loop but your right the 1/3 seems to be a better working model.

Just starting to lay out, not perfect cad work but I'll clean up later. This is my idea where I think we might want to end up at. Whatcha think?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 09/05/2015 03:58 PM
Shell, why do you chose to use the free-space wavelength λ0, a value we meet only outside of the frustum, to calculate your loop antenna diameter?

At 2.47 GHz and with the dimensions of your frustum we should have:
λ0 = 12.1 cm
λb = 14 cm
λs = 31 cm


Since the wavelength varies inside the frustum and is always superior to its value in free-space, shouldn't we calculate the local value of the wavelength according to the diameter of the frustum where you want to put the loop antenna, before deciding of the diameter of the loop antenna? Because of the variation of the wavelength, the loop antenna can't have a fixed diameter. Its diameter depends on its position along the axis in the frustum (I think).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/05/2015 04:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423138#msg1423138">Quote from: flux_capacitor on 09/05/2015 03:58 PM</a>
Shell, why do you chose to use the free-space wavelength λ0, a value we meet only outside of the frustum, to calculate your loop antenna diameter?

At 2.47 GHz and with the dimensions of your frustum we should have:
λ0 = 12.1 cm
λb = 14 cm
λs = 31 cm


Since the wavelength varies inside the frustum and is always superior to its value in free-space, shouldn't we calculate the local value of the wavelength according to the diameter of the frustum where you want to put the loop antenna, before deciding of the diameter of the loop antenna? Because of the variation of the wavelength, the loop antenna can't have a fixed diameter. Its diameter depends on its position along the axis in the frustum (I think).
Are you sure that this is also true for the wave propagating/ traveling along the wire?

EDIT:You are right it can't be Lambda_0. It's a complex issue in our cavity situation based on Propagation constant and Transmission line theory...
For example the antenna distance to the walls also plays a role.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/05/2015 04:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423137#msg1423137">Quote from: SeeShells on 09/05/2015 03:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423132#msg1423132">Quote from: X_RaY on 09/05/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423127#msg1423127">Quote from: SeeShells on 09/05/2015 02:06 PM</a>
The smaller end of the frustum tends to correlate very well to the mode TE012 sizing in  position to the magnetic fields. I scaled a simulation of the magnetic fields and dropped them into a 3D model of the CE frustum and this is what looks like. The placement into the smaller end goes against the wisdom of 1/4 wavelengths in a dipole TExx mode to place it into the larger end but we are exciting a TE mode exciting the magnetic fields with the loop more like a coil winding.

If aero want to excite this configuration it would mirror what X_Ray was thinking in coupling to the modes. butttttt...
I think we are going to have to go to a dual loop placement into the mode shapes using a smaller loop in the smaller end of the cavity with phasing shifted to match the mode magnetic field direction to get a real stable TE012 and I'm working on the drawing and calculations to do just that.

Shell
The Lambda/4 loop seems too tiny while looking at the field configuration. Your 3 Lambda design may work, we will see :)
It is a tiny lambda/4 loop but your right the 1/3 seems to be a better working model.

Just starting to lay out, not perfect cad work but I'll clean up later. This is my idea where I think we might want to end up at. Whatcha think?
Looks interesting if you are focussing on other mode shapes. For TE01p i don't think it will work (too asymmetric around the middle axis, wrong H field of the loops at this position comparing with the mode shape- it is the E "antinode").

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 04:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423138#msg1423138">Quote from: flux_capacitor on 09/05/2015 03:58 PM</a>
Shell, why do you chose to use the free-space wavelength λ0, a value we meet only outside of the frustum, to calculate your loop antenna diameter?

At 2.47 GHz and with the dimensions of your frustum we should have:
λ0 = 12.1 cm
λb = 14 cm
λs = 31 cm


Since the wavelength varies inside the frustum and is always superior to its value in free-space, shouldn't we calculate the local value of the wavelength according to the diameter of the frustum where you want to put the loop antenna, before deciding of the diameter of the loop antenna? Because of the variation of the wavelength, the loop antenna can't have a fixed diameter. Its diameter depends on its position along the axis in the frustum (I think).
2.5GHz was the base frequency used.
So that works out to λ 12 cm

I'm not sure either of the variable loop sizes as we are trying to excite a TExx mode although EWs was ~λ 14 cm.  .55" @2.45GHz.

Tying to check myself here. I even scaled a TE012 mode EW sim into my 3D drawing to see where the field lines were propagating. In the small end the fields look like they are center to center λ 12 cm apart or 6 cm from the centerline of the frustum. In the large end that number goes up. Would it seem you want to excite a mode that those match? I also noticed the intensity of the electrical field was more intense through the center of the small end. 

I must admit I'm still learning here and I very much welcome any thoughts.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 04:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423148#msg1423148">Quote from: X_RaY on 09/05/2015 04:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423137#msg1423137">Quote from: SeeShells on 09/05/2015 03:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423132#msg1423132">Quote from: X_RaY on 09/05/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423127#msg1423127">Quote from: SeeShells on 09/05/2015 02:06 PM</a>
The smaller end of the frustum tends to correlate very well to the mode TE012 sizing in  position to the magnetic fields. I scaled a simulation of the magnetic fields and dropped them into a 3D model of the CE frustum and this is what looks like. The placement into the smaller end goes against the wisdom of 1/4 wavelengths in a dipole TExx mode to place it into the larger end but we are exciting a TE mode exciting the magnetic fields with the loop more like a coil winding.

If aero want to excite this configuration it would mirror what X_Ray was thinking in coupling to the modes. butttttt...
I think we are going to have to go to a dual loop placement into the mode shapes using a smaller loop in the smaller end of the cavity with phasing shifted to match the mode magnetic field direction to get a real stable TE012 and I'm working on the drawing and calculations to do just that.

Shell
The Lambda/4 loop seems too tiny while looking at the field configuration. Your 3 Lambda design may work, we will see :)
It is a tiny lambda/4 loop but your right the 1/3 seems to be a better working model.

Just starting to lay out, not perfect cad work but I'll clean up later. This is my idea where I think we might want to end up at. Whatcha think?
Looks interesting if you are focussing on other mode shapes. For TE01p i don't think it will work (too asymmetric around the middle axis, wrong H field of the loops at this position comparing with the mode shape- it is the E "antinode").
What would you suggest in keeping the dual loops to better excite a single mode? I can vary the phases of the loops if needed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/05/2015 04:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423153#msg1423153">Quote from: SeeShells on 09/05/2015 04:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423148#msg1423148">Quote from: X_RaY on 09/05/2015 04:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423137#msg1423137">Quote from: SeeShells on 09/05/2015 03:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423132#msg1423132">Quote from: X_RaY on 09/05/2015 02:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423127#msg1423127">Quote from: SeeShells on 09/05/2015 02:06 PM</a>
The smaller end of the frustum tends to correlate very well to the mode TE012 sizing in  position to the magnetic fields. I scaled a simulation of the magnetic fields and dropped them into a 3D model of the CE frustum and this is what looks like. The placement into the smaller end goes against the wisdom of 1/4 wavelengths in a dipole TExx mode to place it into the larger end but we are exciting a TE mode exciting the magnetic fields with the loop more like a coil winding.

If aero want to excite this configuration it would mirror what X_Ray was thinking in coupling to the modes. butttttt...
I think we are going to have to go to a dual loop placement into the mode shapes using a smaller loop in the smaller end of the cavity with phasing shifted to match the mode magnetic field direction to get a real stable TE012 and I'm working on the drawing and calculations to do just that.

Shell
The Lambda/4 loop seems too tiny while looking at the field configuration. Your 3 Lambda design may work, we will see :)
It is a tiny lambda/4 loop but your right the 1/3 seems to be a better working model.

Just starting to lay out, not perfect cad work but I'll clean up later. This is my idea where I think we might want to end up at. Whatcha think?
Looks interesting if you are focussing on other mode shapes. For TE01p i don't think it will work (too asymmetric around the middle axis, wrong H field of the loops at this position comparing with the mode shape- it is the E "antinode").
What would you suggest in keeping the dual loops to better excite a single mode? I can vary the phases of the loops if needed.
The mode is given/predicted by the dimensions of the cavity and the frequency you are using. The only question is how good you are able to excite it. Thats aka coupling factor. The possibility of phase shift in your equipment together with the VNA could be very helpful i think.
Try it and tell us what you get with this setup. :)

Can you also adjust the frequency sources? Then you can change to other modes, without changing the dimensions of the resonator.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/05/2015 05:38 PM

@SeeShells
Quote
I'm not sure either of the variable loop sizes as we are trying to excite a TExx mode although EWs was ~λ 14 cm.  .55" @2.45GHz.

Someone correct me if I'm wrong, but I seem to recall that EW was working at 1.93 GHz, not 2.45.

@X-Ray - Thanks, I have moved the detector to (.02, .02, (1/4 wl from SE)) that's x,y,z.

@Dr. Rodal -
Freq.=    2.5   GHZ, c=   299792458   m/s
Wl =   0.1199169832   ~=    0.12   meters
      Quarter wavelength =   0.03   meters

    Frustum   meters       wave lengths      
    length   0.1634          1.3616666667      
        BD   0.295           2.4583333333      
        SD   0.16            1.3333333333      
Taper =  0.8261933905       0.8261933905      
Dia @ ¼ wl = 0.2702141983    2.4335475316   
   
Dia of 1/4 wave lengh loop=            
Circumference/pi = 0.0095492966 0.0795774715      


spelling

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/05/2015 06:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/05/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423059#msg1423059">Quote from: aero on 09/05/2015 03:20 AM</a>

Ok - run finished -  exciting with only Ex and Ey reduced Q to 6661 and reduced the detected resonant frequency by 10 kHz. And in case I didn't mention it, this is with a 1/4 wave length circumference loop, 1/4 wavelength from the big end and centered.

@aero, is it possible to excite it using an impulse rather than a sinusoid? An impulse will draw out the natural resonance of the cavity, and then we can watch it decay to nothing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 06:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423167#msg1423167">Quote from: aero on 09/05/2015 05:38 PM</a>
@SeeShells
Quote
I'm not sure either of the variable loop sizes as we are trying to excite a TExx mode although EWs was ~λ 14 cm.  .55" @2.45GHz.

Someone correct me if I'm wrong, but I seem to recall that EW was working at 1.93 GHz, not 2.45.

@X-Ray - Thanks, I have moved the detector to (.02, .02, (1/4 wl from SE)) that's x,y,z.

@Dr. Rodal -
Freq.=    2.5   GHZ, c=   299792458   m/s
Wl =   0.1199169832   ~=    0.12   meters
      Quarter wavelength =   0.03   meters

    Frustum   meters       wave lengths      
    length   0.1634          1.3616666667      
        BD   0.295           2.4583333333      
        SD   0.16            1.3333333333      
Taper =  0.8261933905       0.8261933905      
Dia @ ¼ wl = 0.2702141983    2.4335475316   
   
Dia of 1/4 wave lengh loop=            
Circumference/pi = 0.0095492966 0.0795774715      


spelling
My translation of what you wrote is the following:

Diameter of your loop =  0.0095493 meters
Diameter of the cone at the loop location =  0.27021 meters

Hence:

(Diameter of your loop)/(Diameter of the cone at the loop location) = (0.0095493 )/(0.27021 )
                                                                                                   =3.5%

in words:  the diameter of your loop is only 3.5 per cent of the diameter of the cone at that location.

CONCLUSION: No wonder that you experience practically no resonance.  Your loop is way too small, its dimensions do not correspond to the ratio that I advised.  Please refer to the images I posted previously.   Your loop was dimensioned NOT taking into account my calculations

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421272#msg1421272


Link:   http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419670#msg1419670

real diameter of antenna =(real diameter of cone at that location )*(diameter of red contour region in the plot below)/(diameter of cone at that location in the plot below)

See the images below again, does it look like the red contour is only 3% of the diameter ? NO.  The loop you are using is an order of magnitude smaller than what it should be.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059926,3Bimage.pagespeed.ic.LXpvXL1fCD.webp)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059928,3Bimage.pagespeed.ic.YHQaUjNJ5z.webp)

I have no idea why you are using the 1/4 free-space wavelength to dimension this loop instead of using the computed wave-patterns.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 09/05/2015 06:28 PM
Use a dual loop on the small end, 180 deg out of phase. See attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 06:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423175#msg1423175">Quote from: Rodal on 09/05/2015 06:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423167#msg1423167">Quote from: aero on 09/05/2015 05:38 PM</a>
@SeeShells
Quote
I'm not sure either of the variable loop sizes as we are trying to excite a TExx mode although EWs was ~λ 14 cm.  .55" @2.45GHz.

Someone correct me if I'm wrong, but I seem to recall that EW was working at 1.93 GHz, not 2.45.

@X-Ray - Thanks, I have moved the detector to (.02, .02, (1/4 wl from SE)) that's x,y,z.

@Dr. Rodal -
Freq.=    2.5   GHZ, c=   299792458   m/s
Wl =   0.1199169832   ~=    0.12   meters
      Quarter wavelength =   0.03   meters

    Frustum   meters       wave lengths      
    length   0.1634          1.3616666667      
        BD   0.295           2.4583333333      
        SD   0.16            1.3333333333      
Taper =  0.8261933905       0.8261933905      
Dia @ ¼ wl = 0.2702141983    2.4335475316   
   
Dia of 1/4 wave lengh loop=            
Circumference/pi = 0.0095492966 0.0795774715      


spelling
My translation of what you wrote is the following:

Diameter of your loop =  0.0095493 meters
Diameter of the cone at the loop location =  0.27021 meters

Hence:

(Diameter of your loop)/(Diameter of the cone at the loop location) = (0.0095493 )/(0.27021 )
                                                                                                   =3.5%

in words:  the diameter of your loop is only 3.5 per cent of the diameter of the cone at that location.

CONCLUSION: No wonder that you experience practically no resonance.  Your loop is way too small, its dimensions do not correspond to the ratio that I advised.  Please refer to the images I posted previously.   Your loop was dimensioned NOT taking into account my calculations

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421272#msg1421272


Link:   http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419670#msg1419670

real diameter of antenna =(real diameter of cone at that location )*(diameter of red contour region in the plot below)/(diameter of cone at that location in the plot below)

See the images below again, does it look like the red contour is only 3% of the diameter ? NO.  The loop you are using is an order of magnitude smaller than what it should be.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059926,3Bimage.pagespeed.ic.LXpvXL1fCD.webp)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059928,3Bimage.pagespeed.ic.YHQaUjNJ5z.webp)

I have no idea why you are using the 1/4 free-space wavelength to dimension this loop instead of using the computed wave-patterns.
Dr. Rodel how can I compare your images and these of EW and draw any conclusions as to what is happening within the cavity? It's a little confusing.

This frustum isn't going to be like the first one which was easy to disassemble and I simply would like to get it right on the first shot, well with a good chance anyway.

Thanks,

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 07:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423179#msg1423179">Quote from: cee on 09/05/2015 06:28 PM</a>
Use a dual loop on the small end, 180 deg out of phase. See attached.
Perfect! This makes a lot of sense Cee, thanks! It also lets the cavity form mode(s) according to the internal dimensions of the cavity walls. The 180 phase shift between the two loops will essentially lock the TE012 mode as well and limit other mode generation if I see this right.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Johnny_Tsunami on 09/05/2015 07:26 PM
Bernoulli principle facing prevailing winds to draw smoke out? Never seen one like that but it makes sense. Will it make thrust? 😄 Cool sci-if movie plot where the hero cuts the top off a chimney, straps a microwave oven and a bomb to it and sends it straight up into the mothership before it can destroy all mankind!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cee on 09/05/2015 07:35 PM
Shell,
Your original sidewall excitation loop design would work as well and probably be easier to implement.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/05/2015 07:46 PM
Loop with coaxial feed (Flux-capacitor dimensions from here: http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269) instead stonehenge ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 07:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423192#msg1423192">Quote from: cee on 09/05/2015 07:35 PM</a>
Shell,
Your original sidewall excitation loop design would work as well and probably be easier to implement.

Cee, they both would be ummm ... not that easy... but I do have a nice piece of flat ceramic plate about 1/4" thick for the top plate that would work quite well at supporting this.

I was thinking about using a solid piece of copper W/O the ceramic attached o the bottom for VNA testing That would allow me easier access to the cavity to get the loops right.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 07:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423195#msg1423195">Quote from: X_RaY on 09/05/2015 07:46 PM</a>
Loop with coaxial feed (Flux-capacitor dimensions from here: http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421269#msg1421269) instead stonehenge ;)
I have to watch how I put something through the center as I have this quartz tuning rod right in the middle X_Ray. But it could come right up beside of it. It wouldn't be that hard to do on just the copper plate for a VNA test would it?

Shell

PS: Need to get out to the shop. BBL

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/05/2015 08:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423197#msg1423197">Quote from: Rodal on 09/05/2015 07:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423183#msg1423183">Quote from: SeeShells on 09/05/2015 06:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423175#msg1423175">Quote from: Rodal on 09/05/2015 06:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423167#msg1423167">Quote from: aero on 09/05/2015 05:38 PM</a>
@SeeShells
Quote
I'm not sure either of the variable loop sizes as we are trying to excite a TExx mode although EWs was ~λ 14 cm.  .55" @2.45GHz.

Someone correct me if I'm wrong, but I seem to recall that EW was working at 1.93 GHz, not 2.45.

@X-Ray - Thanks, I have moved the detector to (.02, .02, (1/4 wl from SE)) that's x,y,z.

@Dr. Rodal -
Freq.=    2.5   GHZ, c=   299792458   m/s
Wl =   0.1199169832   ~=    0.12   meters
      Quarter wavelength =   0.03   meters

    Frustum   meters       wave lengths      
    length   0.1634          1.3616666667      
        BD   0.295           2.4583333333      
        SD   0.16            1.3333333333      
Taper =  0.8261933905       0.8261933905      
Dia @ ¼ wl = 0.2702141983    2.4335475316   
   
Dia of 1/4 wave lengh loop=            
Circumference/pi = 0.0095492966 0.0795774715      


spelling
My translation of what you wrote is the following:

Diameter of your loop =  0.0095493 meters
Diameter of the cone at the loop location =  0.27021 meters

Hence:

(Diameter of your loop)/(Diameter of the cone at the loop location) = (0.0095493 )/(0.27021 )
                                                                                                   =3.5%

in words:  the diameter of your loop is only 3.5 per cent of the diameter of the cone at that location.

CONCLUSION: No wonder that you experience practically no resonance.  Your loop is way too small, its dimensions do not correspond to the ratio that I advised.  Please refer to the images I posted previously.   Your loop was dimensioned NOT taking into account my calculations

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421272#msg1421272


Link:   http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419670#msg1419670

real diameter of antenna =(real diameter of cone at that location )*(diameter of red contour region in the plot below)/(diameter of cone at that location in the plot below)

See the images below again, does it look like the red contour is only 3% of the diameter ? NO.  The loop you are using is an order of magnitude smaller than what it should be.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059926,3Bimage.pagespeed.ic.LXpvXL1fCD.webp)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059928,3Bimage.pagespeed.ic.YHQaUjNJ5z.webp)

I have no idea why you are using the 1/4 free-space wavelength to dimension this loop instead of using the computed wave-patterns.
Dr. Rodel how can I compare your images and these of EW and draw any conclusions as to what is happening within the cavity? It's a little confusing.

This frustum isn't going to be like the first one which was easy to disassemble and I simply would like to get it right on the first shot, well with a good chance anyway.

Thanks,

Shell

Actually, I would go as far as betting:

1) That image

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1064549,3Bimage.pagespeed.ic.Rn-aAD0cE2.webp)

 is not from NASA or from an electromagnetic field computer program calculation


2) If that image intends to convey an electromagnetic field in the TE012 mode, it is incorrect, as the magnetic polar field in the polar angle direction should look like this:

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059922,3Bimage.pagespeed.ic.O3sFa0O7ox.webp)

3) That image does not correspond to any of the electromagnetic fields in the TE012 mode:

a) it is not an image of the transverse electric field in the azimuthal direction

b) it is not a correct image of the H magnetic field in the spherical polar angle direction

c) it is not an image of the H magnetic field in the longitudinal direction
Found it. It had been mislabeled in another post as a TE012 and it's a TE013 by EagleWorks, no wonder I was going what the heck.

Shell

PA Thanks Dr. Rodel! You were right but if is from EW. Now out to the shop. Got a drive to build and as much as I'd love to spend a Saturday chatting with all you great people I have to get booking.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 08:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423201#msg1423201">Quote from: SeeShells on 09/05/2015 08:01 PM</a>
...
PA Thanks Dr. Rodel! You were right but if is from EW. Now out to the shop. Got a drive to build and as much as I'd love to spend a Saturday chatting with all you great people I have to get booking.

Sorry, but I find this confusing, the image (reproduced now at the left for TE013) is not one I recall from NASA Eagleworks. Is it is something that came from NASA, what is the context in which it was produced?  It is also important to establish what are the conditions for the image. Does it include dielectric inserts?  What is the natural frequency?

I attach below the original report by Frank Davis (that I am familiar with, that Paul March made available in thread 2) to verify that the image at the left is NOT something that was in the report from NASA that Paul March made available in thread 2

* There are only 27 pages in Frank Davis report, there is no page 28

* There is no TE013 displayed by Frank Davis in his report, as TE013 for the NASA frustum without dielectric has a natural frequency amply exceeding 2.45 GHz

I attach below the image for TE012 that originated with NASA Eagleworks

I would appreciate anybody being able to trace it to its original message, so that we can verify who is the author, and most relevant what are the conditions for that plot

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 09/05/2015 08:27 PM
Just to let people know there is a small article in the current issue of the New Scientist about Chris Wilson's research into the Casimir effect under the title 'Can We Get Energy From Nothing?'.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 08:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423205#msg1423205">Quote from: X_RaY on 09/05/2015 08:24 PM</a>
...
Seems to be another document? Please look at the Date and compare them.
The image should be traced to its original message to establish who is the author and what are the conditions represented. Does it include dielectric inserts?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/05/2015 09:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423174#msg1423174">Quote from: WarpTech on 09/05/2015 06:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423059#msg1423059">Quote from: aero on 09/05/2015 03:20 AM</a>

Ok - run finished -  exciting with only Ex and Ey reduced Q to 6661 and reduced the detected resonant frequency by 10 kHz. And in case I didn't mention it, this is with a 1/4 wave length circumference loop, 1/4 wavelength from the big end and centered.

@aero, is it possible to excite it using an impulse rather than a sinusoid? An impulse will draw out the natural resonance of the cavity, and then we can watch it decay to nothing.

I'm not using a continuous source, rather it is a Gaussian source centered at the drive frequency with noise bandwidth chosen to mimic a magnetron. Meep literature calls it a "pulse" and it does turn off at some point. I just don't know when and have no control over it. Or maybe I do have an idea of when, because Harminv is commanded to run using the "after-sources" switch and my latest Harminv run terminated with time step 32477 (time=162.385) . For Harminv runs I use resolution = 100, so a time step = 0.5/100 = 0.005 meep time units per time step. check - 32477*0.005 =162.385. So maybe the Gaussian pulse turns off at 162.385 meep seconds.

Normally for imaging I use higher resolution = 250 giving 0.002 time units per time step so 162.385 meep seconds would take 32477*0.005/.002 or 81192.5 time steps.That might be doable, because at 20 time steps per wall clock second it should only take a little over an hour to run 80,000 time steps.

But then I have the problem of figuring out how to make meep write the h5 data after time stepping is finished. Maybe there is a way, I just don't know what it is at the moment. I'll add it to my list.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/05/2015 09:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423175#msg1423175">Quote from: Rodal on 09/05/2015 06:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423167#msg1423167">Quote from: aero on 09/05/2015 05:38 PM</a>
@SeeShells
Quote
I'm not sure either of the variable loop sizes as we are trying to excite a TExx mode although EWs was ~λ 14 cm.  .55" @2.45GHz.

Someone correct me if I'm wrong, but I seem to recall that EW was working at 1.93 GHz, not 2.45.

@X-Ray - Thanks, I have moved the detector to (.02, .02, (1/4 wl from SE)) that's x,y,z.

@Dr. Rodal -
Freq.=    2.5   GHZ, c=   299792458   m/s
Wl =   0.1199169832   ~=    0.12   meters
      Quarter wavelength =   0.03   meters

    Frustum   meters       wave lengths      
    length   0.1634          1.3616666667      
        BD   0.295           2.4583333333      
        SD   0.16            1.3333333333      
Taper =  0.8261933905       0.8261933905      
Dia @ ¼ wl = 0.2702141983    2.4335475316   
   
Dia of 1/4 wave lengh loop=            
Circumference/pi = 0.0095492966 0.0795774715      


spelling
My translation of what you wrote is the following:

Diameter of your loop =  0.0095493 meters
Diameter of the cone at the loop location =  0.27021 meters

Hence:

(Diameter of your loop)/(Diameter of the cone at the loop location) = (0.0095493 )/(0.27021 )
                                                                                                   =3.5%

in words:  the diameter of your loop is only 3.5 per cent of the diameter of the cone at that location.

CONCLUSION: No wonder that you experience practically no resonance.  Your loop is way too small, its dimensions do not correspond to the ratio that I advised.  Please refer to the images I posted previously.   Your loop was dimensioned NOT taking into account my calculations

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421272#msg1421272


Link:   http://forum.nasaspaceflight.com/index.php?topic=38203.msg1419670#msg1419670

real diameter of antenna =(real diameter of cone at that location )*(diameter of red contour region in the plot below)/(diameter of cone at that location in the plot below)

See the images below again, does it look like the red contour is only 3% of the diameter ? NO.  The loop you are using is an order of magnitude smaller than what it should be.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059926,3Bimage.pagespeed.ic.LXpvXL1fCD.webp)

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1059928,3Bimage.pagespeed.ic.YHQaUjNJ5z.webp)

I have no idea why you are using the 1/4 free-space wavelength to dimension this loop instead of using the computed wave-patterns.

Well, maybe Dr. Rodal, its because you don't tell me  what loop circumference is, in units of wave length, that you want. In this case, convert meters to wave length by dividing by 0.12 meters/wave length. I don't need to tell you how to do math so please don't make me guess what your pictures mean.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/05/2015 10:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423206#msg1423206">Quote from: Star One on 09/05/2015 08:27 PM</a>
Just to let people know there is a small article in the current issue of the New Scientist about Chris Wilson's research into the Casimir effect under the title 'Can We Get Energy From Nothing?'.
Well, can we?  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/05/2015 10:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423214#msg1423214">Quote from: aero on 09/05/2015 09:21 PM</a>
...
Well, maybe Dr. Rodal, its because you don't tell me  what loop circumference is, in units of wave length, that you want. In this case, convert meters to wave length by dividing by 0.12 meters/wave length. I don't need to tell you how to do math so please don't make me guess what your pictures mean.
I suggest a loop

diameter ~= 0.054 meters

center located at the axis of axi-symmetry and

~0.054 meters from the small end


Why are you demanding to

<<convert meters to wave length by dividing by 0.12 meters/wave length>>  ???

where

<<Freq.=    2.5   GHZ, c=   299792458   m/s
Wl =   0.1199169832   ~=    0.12   meters>>  ???

as others have pointed out, this is a cavity, the wavelength inside a cavity is not the free space wavelength.  Actually, there is no such thing as "the wavelength" inside the cavity.  As the images show the wavepatterns have different lengths: for example the longitudinal direction wavepatterns are longer near the small base and shorter near the big base.

There is no such thing as a uniform wavelength because the wavepatterns are dictated by Spherical Bessel functions in the longitudinal direction and by associated Legendre functions in the spherical polar direction.  They are not governed by trigonometric harmonic functions.  It is incorrect to use trigonometric harmonic functions in those directions.  The wavepatterns do not have uniform length, and the length is not the free space length either.

Your own calculation shows that the length of the frustum is 1.3617 times the free space wavelength.  There are no integer number of free-space wavelengths that fit inside the frustum, according to your own calculation.

It is not an antenna in free space.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 12:47 AM
I wrote that this image

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1064549,3Bimage.pagespeed.ic.Rn-aAD0cE2.webp)

 is not a correct representation of the magnetic field contour lines in mode TE012.

I just realized what this image represents.  It shows the streamlines of the magnetic vector field H in the planes parallel to the axis of axi-symmetry.  The streamlines of the magnetic vector field are different from the contour plots of any of its components.

This plot should be labeled "streamlines of the magnetic field" to avoid confusion with contour plots.

I still cannot recall this image (and the one for TE013) being presented by Paul March.  It would be nice to know what was the context of this calculation.  Did it include or not include dielectric inserts?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 09/06/2015 01:05 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423221#msg1423221">Quote from: deltaMass on 09/05/2015 10:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423206#msg1423206">Quote from: Star One on 09/05/2015 08:27 PM</a>
Just to let people know there is a small article in the current issue of the New Scientist about Chris Wilson's research into the Casimir effect under the title 'Can We Get Energy From Nothing?'.
Well, can we?  8)

Betteridge's law of headlines - "Any headline that ends in a question mark can be answered by the word no."  :-X

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/06/2015 01:06 AM
Because free space wavelength is unit of measure for setting antenna parameters. Over the last month or so, almost all antenna data was given in fractional wave length and wave length is natural for imaging current around a loop. It makes my task less error prone by using one unit of measure and not changing code for a different measurement system.  I could use furlongs, I guess, but i don't.

I will set a loop antenna  0.054/.12  = 5.4/12 = 0.45 wave lengths of the drive frequency from the small end with a circumference = pi * 0.45 =  1.4137 wave lengths. Then I will make a resonance run and let you know. But now where would you like for me to put the detector? Right now it is 1/4 wavelength from the small end. I think I'll move it back to  the cavity center with offset.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/06/2015 02:09 AM
Aero asked me to run a meep simulation using dual dipoles near the big end of the frustum.  Results are available in the Google Drive at https://drive.google.com/open?id=0B527OOY4hxdZfmhrZmF3TkdyQlVzTFh4a1hJanc1OGN3OVk0MXRfMk9tc1RoeE5zcll6SGc

In the directory at that link, you'll find copies of the control and log files used, as well as a description ("meep-data-description-CE-2r9-32cy.txt" of the run.

The two dipoles are located 30mm from the big end, and are 0.9 * wave length in size.

Below are some of the more than 400 png images available online that show various aspects of the run. Each png file in the png-directory corresponds to a csv file in the csv-directory with the same base name (that is, without the file extension).

Q reported is -59542171.49652831, so almost 60,000,000.

I'm working to automate more of the production of these sorts of runs, and would appreciate guidance from Dr. Rodal and others on the matter of the png contour representations - whether they're useful or not, and how they might be made more useful.  I know there were discussions in the past about useful and less-useful representations, but it's hard for me to draw concrete conclusions from those discussions.  Hopefully, we can renew the dialog and arrive at representations that assist in your analysis.

Regards,
Ed

Edit:  partial key to file names: tt-[he]aa999, where
          tt - time slice
          h - magnetic field
          e - electric field
         aa - two axes such as yx, xz, etc. describing the plane from which the data are drawn
        999 - optional slice offset from the big end to the small end through the long axis of the frustum.
                 big end is 0, small end is 150, antennae are at 30

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 02:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423255#msg1423255">Quote from: Eer on 09/06/2015 02:09 AM</a>
Aero asked me to run a meep simulation using dual dipoles near the big end of the frustum.  Results are available in the Google Drive at https://drive.google.com/open?id=0B527OOY4hxdZfmhrZmF3TkdyQlVzTFh4a1hJanc1OGN3OVk0MXRfMk9tc1RoeE5zcll6SGc

In the directory at that link, you'll find copies of the control and log files used, as well as a description ("meep-data-description-CE-2r9-32cy.txt" of the run.

The two dipoles are located 30mm from the big end, and are 0.9 * wave length in size.

Below are some of the more than 400 png images available online that show various aspects of the run. Each png file in the png-directory corresponds to a csv file in the csv-directory with the same base name (that is, without the file extension).

Q reported is -59542171.49652831, so almost 60,000,000.

I'm working to automate more of the production of these sorts of runs, and would appreciate guidance from Dr. Rodal and others on the matter of the png contour representations - whether they're useful or not, and how they might be made more useful.  I know there were discussions in the past about useful and less-useful representations, but it's hard for me to draw concrete conclusions from those discussions.  Hopefully, we can renew the dialog and arrive at representations that assist in your analysis.

Regards,
Ed

Edit:  partial key to file names: tt-[he]aa999, where
          tt - time slice
          h - magnetic field
          e - electric field
         aa - two axes such as yx, xz, etc. describing the plane from which the data are drawn
        999 - optional slice offset from the big end to the small end through the long axis of the frustum.
                 big end is 0, small end is 150, antennae are at 30

I just saw this and I did not want to delay thanking you for the huge amount of work that this represents.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 02:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423255#msg1423255">Quote from: Eer on 09/06/2015 02:09 AM</a>
Aero asked me to run a meep simulation using dual dipoles near the big end of the frustum.  Results are available in the Google Drive at https://drive.google.com/open?id=0B527OOY4hxdZfmhrZmF3TkdyQlVzTFh4a1hJanc1OGN3OVk0MXRfMk9tc1RoeE5zcll6SGc

In the directory at that link, you'll find copies of the control and log files used, as well as a description ("meep-data-description-CE-2r9-32cy.txt" of the run.

The two dipoles are located 30mm from the big end, and are 0.9 * wave length in size.

Below are some of the more than 400 png images available online that show various aspects of the run. Each png file in the png-directory corresponds to a csv file in the csv-directory with the same base name (that is, without the file extension).

Q reported is -59542171.49652831, so almost 60,000,000.

I'm working to automate more of the production of these sorts of runs, and would appreciate guidance from Dr. Rodal and others on the matter of the png contour representations - whether they're useful or not, and how they might be made more useful.  I know there were discussions in the past about useful and less-useful representations, but it's hard for me to draw concrete conclusions from those discussions.  Hopefully, we can renew the dialog and arrive at representations that assist in your analysis.

Regards,
Ed

Edit:  partial key to file names: tt-[he]aa999, where
          tt - time slice
          h - magnetic field
          e - electric field
         aa - two axes such as yx, xz, etc. describing the plane from which the data are drawn
        999 - optional slice offset from the big end to the small end through the long axis of the frustum.
                 big end is 0, small end is 150, antennae are at 30
Just got in from the shop a bit ago, long day and logged on and saw this work.

Thank you for running all of this, it is a ton of work. I'll be digging through it.

Thank You Ed.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/06/2015 03:15 AM
Maybe this will make some waves 8) But will it hold water?


http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 03:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423265#msg1423265">Quote from: Mulletron on 09/06/2015 03:15 AM</a>
Maybe this will make some waves 8) But will it hold water?


http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime

Here is the original article by Prof. Jack Wisdom (MIT):

http://web.mit.edu/wisdom/www/swimming.pdf

For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m

Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.

Quote from: Jack Wisdom
The curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/06/2015 04:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423267#msg1423267">Quote from: Rodal on 09/06/2015 03:35 AM</a>

Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.


Yeah when I saw the animation below, I was thinking of the air inside the cavity being expanded and compressed as it cycled in a loop from small to large end and back.

http://video.scientificblogging.com/video/swimming-in-space-avi

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/06/2015 06:03 AM
After some more thought, I realize I was in error. Dr. Rodal didn't say it but I can't use wave length as a unit of geometric measure. It's a variable length ruler. When making resonance runs and changing frequency to find resonance, I have been moving the antenna and changing its circumference. That doesn't work. So lets try this:

REVISED
All DYI'ers. Acceptable loop antenna specification is "circumference of the loop" in meters. The x, y and z coordinate location of the center of the loop must also be specified in meters  and referenced to either the 0, 0, 0 point at the mid-point of the axis of rotation of the cavity, or to one or the other of the inside face of the big or small end and the side wall.

This requirement for sound specification also holds for dipole and stub antennas, just substitute length for circumference and dipole or stub for loop and add axial or lateral orientation. I can no longer accept wavelength as a descriptor of size or location of the antenna.

Again, all dimensions must be specified in meters, a fixed number that does not vary in different meep runs


I will make the required changes to my control file and re-run some or all CE2 resonance runs. (Using the model without a floating and morphing antenna.)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 09/06/2015 11:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423203#msg1423203">Quote from: Rodal on 09/05/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423201#msg1423201">Quote from: SeeShells on 09/05/2015 08:01 PM</a>
...
PA Thanks Dr. Rodel! You were right but if is from EW. Now out to the shop. Got a drive to build and as much as I'd love to spend a Saturday chatting with all you great people I have to get booking.

Sorry, but I find this confusing, the image (reproduced now at the left for TE013) is not one I recall from NASA Eagleworks. Is it is something that came from NASA, what is the context in which it was produced?  It is also important to establish what are the conditions for the image. Does it include dielectric inserts?  What is the natural frequency?

I attach below the original report by Frank Davis (that I am familiar with, that Paul March made available in thread 2) to verify that the image at the left is NOT something that was in the report from NASA that Paul March made available in thread 2

* There are only 27 pages in Frank Davis report, there is no page 28

* There is no TE013 displayed by Frank Davis in his report, as TE013 for the NASA frustum without dielectric has a natural frequency amply exceeding 2.45 GHz

I attach below the image for TE012 that originated with NASA Eagleworks

I would appreciate anybody being able to trace it to its original message, so that we can verify who is the author, and most relevant what are the conditions for that plot

All these images come from Eagleworks.

The one you show is indeed from Frank Davies' 2014 progress report, posted by Paul March in this message of the EM Drive Thread 2 (http://forum.nasaspaceflight.com/index.php?topic=36313.msg1333246#msg1333246). The document is entitled "Copper Frustum modes" and the file name is "Frustrum modes overview 2A.pdf". Paper reattached below. TE012 mode is page 18 and calculated for a frequency of 2.1794 GHZ without dielectric. The image shows magnetic H-field vectors in blue and electric E-field vectors in red:

(TE012_from_Frustum_modes_overview_2A.png)
"Without a dielectric" because the caption is 2.1794 GHZ, which is the frustum resonant frequency for this mode, whereas the resonant frequency measured by Eagleworks with 2 PE discs inside was 1.8803 GHz for the same TE012 mode.

See also Eagleworks' 2014 main paper (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf), figure 15 page 12, which also shows TE012 mode with a dielectric:

(TE012_from_AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.png)
"With a dielectric" because the text states:
Quote
The COMSOL analysis iteration process was used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster. The geometry of the RF resonator disc is a function of the resonator material’s relative permittivity, dissipation factor, and target resonance mode.

You can see the H and E vectors are quite similar with or without a dielectric, for this TE012 mode.

The TE012 mode published by SeeShells and I (along the TE013 version), showing magnetic streamlines in blue, are also from Eagleworks. Those images come from another 2014 report by Davies entitled "Notes on fields in a frustrum type chamber". I can't find where it has been posted the first time (I think by TheTraveller), so I reattach the paper to this message. Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing:

(http://ayuba.fr/images/emdrive/TE012_from_Notes on_fields_in_a_frustrum_type_chamber.png)

Retrieving this file I am shocked to find an important information I didn't see before: those TE/TM modes simulations by Davies (25 March 2014) are based not on Eagleworks' frustum, but Yang's frustum with "proportions estimated from Chinese paper" by Davies!!!!!

Chinese proportions which would be, according to Davies:

Db = L and Ds = Db/2

(Yang_frustum_proportions_estimated_by_Eagleworks_from_Chinese_paper.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/06/2015 12:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423321#msg1423321">Quote from: flux_capacitor on 09/06/2015 11:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423203#msg1423203">Quote from: Rodal on 09/05/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423201#msg1423201">Quote from: SeeShells on 09/05/2015 08:01 PM</a>
...
PA Thanks Dr. Rodel! You were right but if is from EW. Now out to the shop. Got a drive to build and as much as I'd love to spend a Saturday chatting with all you great people I have to get booking.

Sorry, but I find this confusing, the image (reproduced now at the left for TE013) is not one I recall from NASA Eagleworks. Is it is something that came from NASA, what is the context in which it was produced?  It is also important to establish what are the conditions for the image. Does it include dielectric inserts?  What is the natural frequency?

I attach below the original report by Frank Davis (that I am familiar with, that Paul March made available in thread 2) to verify that the image at the left is NOT something that was in the report from NASA that Paul March made available in thread 2

* There are only 27 pages in Frank Davis report, there is no page 28

* There is no TE013 displayed by Frank Davis in his report, as TE013 for the NASA frustum without dielectric has a natural frequency amply exceeding 2.45 GHz

I attach below the image for TE012 that originated with NASA Eagleworks

I would appreciate anybody being able to trace it to its original message, so that we can verify who is the author, and most relevant what are the conditions for that plot

All these images come from Eagleworks.

The one you show is indeed from Frank Davies' 2014 progress report, posted by Paul March in this message of the EM Drive Thread 2 (http://forum.nasaspaceflight.com/index.php?topic=36313.msg1333246#msg1333246). The document is entitled "Copper Frustum modes" and the file name is "Frustrum modes overview 2A.pdf". Paper reattached below. TE012 mode is page 18 and calculated for a frequency of 2.1794 GHZ without dielectric. The image shows magnetic H-field vectors in blue and electric E-field vectors in red:


"Without a dielectric" because the caption is 2.1794 GHZ, which is the frustum resonant frequency for this mode, whereas the resonant frequency measured by Eagleworks with 2 PE discs inside was 1.8803 GHz for the same TE012 mode.

See also Eagleworks' 2014 main paper (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf), figure 15 page 12, which also shows TE012 mode with a dielectric:

"With a dielectric" because the text states:
Quote
The COMSOL analysis iteration process was used prior to assembly to determine the optimal thickness and diameter of the dielectric RF resonator disc located at the small end of the thruster. The geometry of the RF resonator disc is a function of the resonator material’s relative permittivity, dissipation factor, and target resonance mode.

You can see the H and E vectors are quite similar with or without a dielectric, for this TE012 mode.

The TE012 mode published by SeeShells and I (along the TE013 version), showing magnetic streamlines in blue, are also from Eagleworks. Those images come from another 2014 report by Davies entitled "Notes on fields in a frustrum type chamber". I can't find where it has been posted the first time (I think by TheTraveller), so I reattach the paper to this message. Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing:



Retrieving this file I am shocked to find an important information I didn't see before: those TE/TM modes simulations by Davies (25 March 2014) are based not on Eagleworks' frustum, but Yang's frustum with "proportions estimated from Chinese paper" by Davies!!!!!

Chinese proportions which would be, according to Davies:

Db = L and Ds = Db/2


Interesting are the modes shapes like "TM0(1.5)2" in that document.
I had some thoughts in something like that sometimes ago(but never post that).  Really enlightening!  :)
Thanks for this quote.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 12:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423321#msg1423321">Quote from: flux_capacitor on 09/06/2015 11:22 AM</a>
[...
All these images come from Eagleworks.

....
The TE012 mode published by SeeShells and I (along the TE013 version), showing magnetic streamlines in blue, are also from Eagleworks. Those images come from another 2014 report by Davies entitled "Notes on fields in a frustrum type chamber". I can't find where it has been posted the first time (I think by TheTraveller), so I reattach the paper to this message. Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing:...

Thank you so much for going through the trouble to find out this report:

http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=38203.0;attach=1064610

by Davies (?) entitled "Notes on fields in a frustrum type chamber"

I note that you could not find either any post by Paul March introducing this report.

It is also my recollection that these images first made it into the thread by a post by TheTraveller.

I have been here since thread 1 and I do NOT recall any post from Paul March, or any discussion with Paul March about this report.  I carefully read every post by Paul March and I don't recall this report being attached or discussed by Paul March.   On the other hand I do NOT read as carefully many of TheTraveller's posts.  So I don't understand how this report by Davis became public.

So the question still stands: how did this internal NASA report and its images make it into the thread and become public ???

////////////////////////////////////


Concerning the question:

Quote
Whatever I don't understand how streamlines would be a problem instead of field vectors, since streamlines show the path drawn if you link the vectors together, like in a "connecting the dot" game. To me it is the same thing

The answer is simple: SeeShells asked me how to reconcile my contour plots with the images posted by TheTraveller, it is an excellent question, because the images were NOT posted with any title indicating whether these  were contour lines or streamlines.  They are NOT the same thing, they are completely different.

If you have a plot with lines, and NO title indicating whether it is contour plot or a streamline plot, you cannot ascertain whether it is a contour plot or a streamline plot.

The contour plot of the electromagnetic field components are completely different from the streamline plots of the field vectors.

Frank Davis makes this distinction clear on page 4 of his report, where he writes

<<Notice how streamlines can mislead about where field strength is highest. Electric field is concentrated at the wide part>>

yes, streamlines can be  very MISLEADING, particularly when they are not labeled as such.  I have only shown contour line plots, or alternatively I have shown field vectors for my plots, but never streamlines without vectors, for that reason.

This distinction is very important for the discussion with Shell and Aero, regarding where to place the antenna loop and what the dimensions of the loop should be.



Without a title indicating what the plot is (whether a contour plot or a streamline plot) one is lost.  Of course, if the field vectors are shown on top of the streamlines one can ascertain that the lines are streamlines.  But here we had a plot just with lines on the left, and another plot with field vectors on the right.  Without a title one could think that one plot was a contour plot or a streamline plot.  One wouldn't know.

Of course, upon further examination one concludes that it is a streamline plot because the plot as shown would be an incorrect contour plot (this is the conclusion at which I arrived independently in a previous post, without having the benefit of seeing the report).

//////////////////////////////

It is so evident that this report was not ever introduced or discussed by Paul March into this thread that you yourself are shocked to find out that this report refers to a Yang fustrum and NOT to the Eagleworks frustum

To refresh people's minds, we had a long discussion regarding Yang/Shell frustum, in that discussion I was of the firm opinion that the 6 degree cone angle geometry could NOT be the geometry of the Yang shell.  Most other people in the thread at that time were disagreeing with me saying that I was overinterpreting Yang's drawings.

At the time of those discussions, none of us knew about the existence of this report, that actually gives the geometry for Yang's frustum

This report agrees with my interpretation: the Yang/Shell 6 degree geometry is NOT the geometry of the Yang shell, the geometry of the Yang shell has a much greater cone angle, and hence the ratio between the big base and the small base is signficantly greater than 1.

The dimensions chosen by Frank Davis are similar to the dimensions I concluded that Yang's frustum should have:

Length = 0.24 m   
Big Base = 0.247 m   
Small Base = 0.114425 m

In other words:

Length ~ Big Base

Small Base ~ (Big Base)/2

Completely different from the Yang/Shell 6 degree geometry.

Furthermore, when we were discussing these images with Shell, not knowing whether the lines were streamlines or contour lines,  the assumption was that the geometry represented was that of the Eagleworks frustum.  Looking at this report, that assumption was completely incorrect:  those images are not for the Eagleworks frustum, instead they are for the Chinese frustum !!!!!

So, I am sure glad that I asked where did these images come from, and that you found the report, as the images were not of the Eagleworks frustum, but instead they were of the Chinese frustum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 09/06/2015 01:50 PM
I understand it is normal for the magnetron to get very hot during operation, and this is exacerbated if there is a large impedance mismatch.

Is there a similar expectation that a resonator will also get warm or even hot?

Thanks.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/06/2015 02:01 PM
Yes, you certainly have the right idea here. With a perfect match, no power is reflected back to the magnetron, and that naturally minimises magnetron heating. Correspondingly, all the power is dissipated as real heat in the conducting walls of the cavity. This is just the same as a perfect match to any circuit, where all power is dissipated as heat in the ESR of the circuit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 02:04 PM
TE012_from_Frustum_modes_overview_2A.png

Looking at the geometry of this frustum I came up with a ratio Be to Se of 1.8 to 1.
Using a arbitrary number with a ruler tool for generating the % of size difference in the Be vs Se by pasting the file into Sketchup and getting diameter measurements of Be=2.7 and Se 1.5,  it is a 1.8:1 ratio.

Interestingly enough the current CE design is 1.8 to 1. ~ 300mm/165mm 1.81:1 when I'm finalized with building it. Although the center plate to plate ratio is different I think I can fine tune the TE012 in with the adjustable floating top plate if needed.

Shell
 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/06/2015 02:44 PM
Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 02:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423358#msg1423358">Quote from: deltaMass on 09/06/2015 02:44 PM</a>
Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.  8)
 :o 1.618  ::)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/06/2015 02:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423362#msg1423362">Quote from: SeeShells on 09/06/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423358#msg1423358">Quote from: deltaMass on 09/06/2015 02:44 PM</a>
Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.  8)
 :o 1.618  ::)

So - mystical numerology - applying the golden ratio to the dimensions of a frustum, what harmonic frequency will resonate?  Or, inversely, given the golden ratio as a gigahertz frequency, what shape of a frustum will resonate at that frequency?

Inquiring minds want to know ...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 03:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423364#msg1423364">Quote from: Eer on 09/06/2015 02:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423362#msg1423362">Quote from: SeeShells on 09/06/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423358#msg1423358">Quote from: deltaMass on 09/06/2015 02:44 PM</a>
Since EmDrive is well out on the fringe in any case, one might as well go whole hog and seek to relate all ratios to the Golden Ratio.  8)
 :o 1.618  ::)

So - mystical numerology - applying the golden ratio to the dimensions of a frustum, what harmonic frequency will resonate?  Or, inversely, given the golden ratio as a gigahertz frequency, what shape of a frustum will resonate at that frequency?

Inquiring minds want to know ...
I need to measure this engine first to give you an answer.
propulsion.jpg
Maybe I'll ask my assistant.
816070_halloween-young-frankenstein-igor-halloweeen-countdown_200s.gif

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 03:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423267#msg1423267">Quote from: Rodal on 09/06/2015 03:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423265#msg1423265">Quote from: Mulletron on 09/06/2015 03:15 AM</a>
Maybe this will make some waves 8) But will it hold water?


http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime

Here is the original article by Prof. Jack Wisdom (MIT):

http://web.mit.edu/wisdom/www/swimming.pdf

For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m

Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.

Quote from: Jack Wisdom
The curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.

Notice that all the "frame independence absolutists" that like to write ad nauseam about trivial frame-independence, are all of a sudden speechless concerning this paper by an MIT Professor showing that one can actually use General Relativity to swim in space (albeit at an extremely small "stroke" of 10^(-23) m :)   )


No need for negative mass !!
No need for Woodward's Mach Effect  !!
No need for Quantum Vacuum !!


to do this.

What is required is a deformable object (I always noticed that "frame independent absolutists" invariable portray bodies as rigid and isotropic !!! ) and a gravitational field in General Relativity

So much for their "frame independence" absolutism that an astronaut cannot swim in space.  So much ink in here and in Reddit has been wasted about "frame-independence" arguments.  How do they deal with this counter-example?

Contrary to the "self-appointed experts on frame-independence", General Relativity allows, rather than prevents, swimming in space :)

Here is more:  http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 04:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423370#msg1423370">Quote from: Rodal on 09/06/2015 03:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423267#msg1423267">Quote from: Rodal on 09/06/2015 03:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423265#msg1423265">Quote from: Mulletron on 09/06/2015 03:15 AM</a>
Maybe this will make some waves 8) But will it hold water?


http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime

Here is the original article by Prof. Jack Wisdom (MIT):

http://web.mit.edu/wisdom/www/swimming.pdf

For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m

Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.

Quote from: Jack Wisdom
The curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.

Notice that all the "frame independence absolutists" that like to write ad nauseam about trivial frame-independence, are all of a sudden speechless concerning this paper by an MIT Professor showing that one can actually use General Relativity to swim in space (albeit at an extremely small "stroke" of 10^(-23) m :)   )


No need for negative mass !!
No need for Jim Woodward  !!
No need for Quantum Vacuum !!


to do this.

What is required is a deformable object (I always noticed that "frame independent absolutists" invariable portray bodies as rigid and isotropic !!! ) and a gravitational field in General Relativity

So much for their "frame independence" absolutism that an astronaut cannot swim in space.  So much ink in here and in Reddit has been wasted about "frame-independence" arguments.  How do they deal with this counter-example?

Contrary to the "self-appointed experts on frame-independence", General Relativity allows, rather than prevents, swimming in space :)

Here is more:  http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time

Another unproven mantra repeated ad-nauseam in these threads and in Reddit is that "New Physics" are needed.

This swimming in space counter-example shows the opposite: NO new Physics needed. All that is needed for swimming in space is General Relativity.  NOT new. It has been around for 100 years.

What is needed is for people to stop modeling bodies as being rigid and isotropic.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 04:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423370#msg1423370">Quote from: Rodal on 09/06/2015 03:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423267#msg1423267">Quote from: Rodal on 09/06/2015 03:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423265#msg1423265">Quote from: Mulletron on 09/06/2015 03:15 AM</a>
Maybe this will make some waves 8) But will it hold water?


http://www.science20.com/hammock_physicist/swimming_through_empty_space
http://news.sciencemag.org/2003/02/swimming-through-spacetime

Here is the original article by Prof. Jack Wisdom (MIT):

http://web.mit.edu/wisdom/www/swimming.pdf

For a meter-sized object performing meter-sized deformations at the surface of the Earth, the
displacement is of order 10^(-23) m

Nevertheless, here is an example of how General Relativity allows propellant-less motion in space.

Quote from: Jack Wisdom
The curvature of spacetime is very slight,
so the ability to swim in spacetime is unlikely
to lead to new propulsion devices. For a
meter-sized object performing meter-sized
deformations at the surface of the Earth, the
displacement is of order 10^(-23) m . Nevertheless,
the effect is interesting as a matter
of principle. You cannot lift yourself by pulling
on your bootstraps, but you can lift yourself
by kicking your heels.

Notice that all the "frame independence absolutists" that like to write ad nauseam about trivial frame-independence, are all of a sudden speechless concerning this paper by an MIT Professor showing that one can actually use General Relativity to swim in space (albeit at an extremely small "stroke" of 10^(-23) m :)   )


No need for negative mass !!
No need for Jim Woodward  !!
No need for Quantum Vacuum !!


to do this.

What is required is a deformable object (I always noticed that "frame independent absolutists" invariable portray bodies as rigid and isotropic !!! ) and a gravitational field in General Relativity

So much for their "frame independence" absolutism that an astronaut cannot swim in space.  So much ink in here and in Reddit has been wasted about "frame-independence" arguments.  How do they deal with this counter-example?

Contrary to the "self-appointed experts on frame-independence", General Relativity allows, rather than prevents, swimming in space :)

Here is more:  http://physics.stackexchange.com/questions/46180/can-a-deformable-object-swim-in-curved-space-time
At least something makes sense, even if it's a tiny bit of sense and a tiny bit of movement.

Doc, you should tell those "self-appointed experts on frame-independence" .

"Come over to the Dark Side"
     "You Have Cookies".

Shell

PS: I know I made a joke of a very serious matter you pointed out, but trying to convince some of those guys is silly in itself. I've said extraordinary claims need extraordinary evidence not more extraordinary claims.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/06/2015 04:23 PM
Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw  ;) ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 04:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423378#msg1423378">Quote from: deltaMass on 09/06/2015 04:23 PM</a>
Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw  ;) ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
Aren't we squeezing things up a little like a black hole in the frustum with the wave actions? So it should "Go Faster"?  :-\

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 04:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423378#msg1423378">Quote from: deltaMass on 09/06/2015 04:23 PM</a>
Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw  ;) ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
Concerning Noether, she just formalized something that was already known before her.  Repeating "Noether" ad nasueam is not informative or clarifying. 
 
The point is that one can swim in space, all you need is General Relativity.

No "New Physics" are required and the mistake that deniers make is to invoke trivial assumptions of bodies as being rigid and isotropic.  The point is that people making trivial statements about conservation and rigidity state that no motion such as swimming in space is possible, and this has been proven to be incorrect.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/06/2015 04:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423380#msg1423380">Quote from: Rodal on 09/06/2015 04:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423378#msg1423378">Quote from: deltaMass on 09/06/2015 04:23 PM</a>
Although swimming in spacetime is indeed possible per GR (and it goes much faster close to a black hole event horizon btw  ;) ) one still cannot extract useful work from the process. No conservation laws are broken and Queen Emmy (Noether) continues to reign supreme.
Concerning Noether, she just formalized something that was already known before her.  Repeating "Noether" ad nasueam is not informative or clarifying. 
 
The point is that one can swim in space, all you need is General Relativity.

No "New Physics" are required and the mistake that deniers make is to invoke trivial assumptions of bodies as being rigid and isotropic.  They make trivial statements about conservation of Energy and Momentum.  Of course they are conserved.

The point is that people making trivial statements about conservation and rigidity state that no motion such as swimming in space is possible, and this has been proven to be incorrect.
.

Understanding of the consequences of a nonlinear theory like General Relativity only comes from exploration of mathematical solutions (and their eventual experimental confirmation) rather than from general statements.

Physics is not a Legal profession where one learns "laws", physics is an experimental and mathematical subject of exploration of Nature, not one of regurgitation of Laws.

Prof. Jack Wisdom at MIT has a wonderful book on Functional Differential Geometry, that rather than invoke Noether, emphasizes obtaining mathematical solutions, The approach taken and used in their classes at MIT for many years differs from the conventional one in several ways, mainly Wisdom's integration of computer programming into their explanations, from the very beginning. By programming a computer to interpret a formula, the student soon learns whether or not a formula is correct. Students are led to improve their program, and as a result improve their understanding richer language of vector fields and differential forms.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/06/2015 05:10 PM
In all fairness to the subject matter it needs to be mentioned that interpretation of conservation laws in the context of GR has been the subject of a protracted, educated, passionate and often bitter controversy.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 06:23 PM
I found my steampunk magnetron. Love this!
http://www.ebay.com/itm/Rare-Western-Electric-Type-5780-Magnetron-NOS-Radar-Vacuum-Tube-Vintage-JAN-/181609285094?hash=item2a48c1c5e6
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/06/2015 06:26 PM
Here are my test results for evaluating my changes to the loop antenna, measuring in meters and not wavelengths. It turns out that using wave lengths was easy, using meters was easy too, after I calculated the number of wave lengths per meter lengths. I think it is right but here is some data to check. Use 0.3 meters per meep length unit.

For frequency ~2.50 GHz, (fsi = 2.495e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 283.0
 half wave length meep = 0.20026216299265198
 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 1.4118659990377505
 meep frequency = 2.496727252558168
Loop antenna created


And for frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 283.0
 half wave length meep = 0.10013108149632599
 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


Attached are images of the loop at the end of the 3 cycle run.

Plot scale is the same so as you can see, the loop size is independent of wavelength. This is Dr. Rodal's loop, 0.054 meters in diameter. With the fixed circumference in meters, the number of points around the loop depend only on the meep resolution (=250) so are the same in these two runs.

I think it's right. Evaluations?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 06:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423400#msg1423400">Quote from: aero on 09/06/2015 06:26 PM</a>
Here are my test results for evaluating my changes to the loop antenna, measuring in meters and not wavelengths. It turns out that using wave lengths was easy, using meters was easy too, after I calculated the number of wave lengths per meter lengths. I think it is right but here is some data to check. Use 0.3 meters per meep length unit.

For frequency ~2.50 GHz, (fsi = 2.495e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 283.0
 half wave length meep = 0.20026216299265198
 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 1.4118659990377505
 meep frequency = 2.496727252558168
Loop antenna created


And for frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 283.0
 half wave length meep = 0.10013108149632599
 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


Attached are images of the loop at the end of the 3 cycle run.

Plot scale is the same so as you can see, the loop size is independent of wavelength. This is Dr. Rodal's loop, 0.054 meters in diameter. With the fixed circumference in meters, the number of points around the loop depend only on the meep resolution (=250) so are the same in these two runs.

I think it's right. Evaluations?
Give us a gif sequence of Dr. Rodel's antenna. I'll make a animation to see if it evolves the wave patterns correctly.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/06/2015 06:48 PM
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/06/2015 06:57 PM
@SeeShells

Here - The case for frequency ~2.5 GHz, above.

https://drive.google.com/folderview?id=0B1XizxEfB23tZ0lMS0xyQkp4ZWs&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tZ0lMS0xyQkp4ZWs&usp=sharing)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/06/2015 07:07 PM

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 09/06/2015 07:12 PM
All this talk about "swimming" in space got me thinking: what if the Emdrive really is just doing that?

A thruster that makes an object move in discrete 'hops' (Planck-scale sized?) while energy is being spent but that does not really change momentum... would mean that the system would recover its "speed" immediately after the thruster is turned off (because it never gained any real speed anyway), regardless of the reference frame we are using.

The changes in position would, of course, cause changes in potential energy, but those can be accounted for by the energy spent "swimming" in the gravitational fields, resulting in net conservation of energy and momentum.

Rather than being 'reactionless', this would be a 'momentumless'  drive.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CW on 09/06/2015 07:19 PM
@Rodal

Every time the term 'New Physics' comes up, I can hardly suppress my laughter. Physics in itself is, what it is; it does not care about us puny humans' opinions about it. It has a reality of its own, that we can hardly access in its depth. There are no absolute 'physical laws', just 'falsifiable physical theories by humans' about reality that we can construct from empirical data. Falsifiable theories are obviously the best that our helpless little mammal brains can come up with so far. But it seems to work out pretty good, I dare say.

What technology does, is in fact this: Arranging matter and energy in patterns that are highly unlikely to occur in 'natural' / statistical processes, to create a desired effect. By doing so, we can access deeper or other parts of physical reality. Just think about particle accelerators - extremely unlikely to occur objects in unmanipulated 'nature' that enable us to see otherwise 'hidden' parts of physical reality.

Applying my reasoning on EM-drive like structures, it could very well be that we accidentally stumbled upon a perhaps still very clumsily and ineffectively constructed pattern of matter and energy, that opens a little window into a specific layer of physical reality, that was always there from the beginning - but inaccessible. Opening these windows to new aspects of physical reality to their fullest is maybe the greatest privilege that being a true physicist can offer.

The future is ours to take.

Over and out.
-CW
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 09/06/2015 07:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423398#msg1423398">Quote from: SeeShells on 09/06/2015 06:23 PM</a>
I found my steampunk magnetron. Love this!
http://www.ebay.com/itm/Rare-Western-Electric-Type-5780-Magnetron-NOS-Radar-Vacuum-Tube-Vintage-JAN-/181609285094?hash=item2a48c1c5e6

Hmm...  Just the thing to power my new assault dirigible...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 07:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Quite an interesting wave pattern.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 08:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
It should be quite interesting to run to see if the large plate position of the loop helps or hinders a TE mode generation. Don't expect a huge Q, EW didn't in their loops.

May I ask why we are going with this other software for postprocessing the CSV time slices?

I've been looking at Paraview to do some postprocessing, have you or anyone else here have any feedback on it as a post processor on the csv files?

Today I'm staying out of the lab, need the break and my house needs cleaning, washing done, and I need to cook something other than a TV dinner. Maybe some fried chicken and mashed potatoes with fresh roasted corn on the cob, does a body good.... :D So between loads I'm looking at Paraview.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/06/2015 09:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423426#msg1423426">Quote from: SeeShells on 09/06/2015 08:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
It should be quite interesting to run to see if the large plate position of the loop helps or hinders a TE mode generation. Don't expect a huge Q, EW didn't in their loops.

May I ask why we are going with this other software for postprocessing the CSV time slices?

I've been looking at Paraview to do some postprocessing, have you or anyone else here have any feedback on it as a post processor on the csv files?

Today I'm staying out of the lab, need the break and my house needs cleaning, washing done, and I need to cook something other than a TV dinner. Maybe some fried chicken and mashed potatoes with fresh roasted corn on the cob, does a body good.... :D So between loads I'm looking at Paraview.

Shell

I'm working with paraview, too - it's able to read the h5 files directly, if you use a script I've found to create the xdmf descriptor file that tells paraview how to parse the h5 file.  Let me know if I can research anything for you with it, and I'll see what I can figure out.

PNG file generation has been problematic due to difficulties figuring out what acceptable scaling factors and contour shape algorithms folks prefer to use.  Seems to involve different, and sometimes conflicting, alternatives - tradeoffs between visually appealing, sufficient dynamic range to be able to see different levels and recognize them, and the ability to compare multple related images if they're not scaled the same way ...

Visualization is, I'm convinced, more of a graphic art than a representational science.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/06/2015 09:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423421#msg1423421">Quote from: SeeShells on 09/06/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Quite an interesting wave pattern.

They may all look like that without the auto scaling. Maybe I'll find time to check.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 10:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423431#msg1423431">Quote from: Eer on 09/06/2015 09:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423426#msg1423426">Quote from: SeeShells on 09/06/2015 08:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
It should be quite interesting to run to see if the large plate position of the loop helps or hinders a TE mode generation. Don't expect a huge Q, EW didn't in their loops.

May I ask why we are going with this other software for postprocessing the CSV time slices?

I've been looking at Paraview to do some postprocessing, have you or anyone else here have any feedback on it as a post processor on the csv files?

Today I'm staying out of the lab, need the break and my house needs cleaning, washing done, and I need to cook something other than a TV dinner. Maybe some fried chicken and mashed potatoes with fresh roasted corn on the cob, does a body good.... :D So between loads I'm looking at Paraview.

Shell

I'm working with paraview, too - it's able to read the h5 files directly, if you use a script I've found to create the xdmf descriptor file that tells paraview how to parse the h5 file.  Let me know if I can research anything for you with it, and I'll see what I can figure out.

PNG file generation has been problematic due to difficulties figuring out what acceptable scaling factors and contour shape algorithms folks prefer to use.  Seems to involve different, and sometimes conflicting, alternatives - tradeoffs between visually appealing, sufficient dynamic range to be able to see different levels and recognize them, and the ability to compare multple related images if they're not scaled the same way ...

Visualization is, I'm convinced, more of a graphic art than a representational science.
I want to thank you for your work and help.

And sadly (or not) I'm a very visual lady, stupid patterns. ;) Some here are not as much and that's the issue.

I don't particularly care to see the lowest artifacts that meep can generate, especially if it's on a sliding scale, seeing the lowest artifacts make little sense in the frustum.  I've been looking for mode generation, traveling modes, and how they decay and where. And especially I'm focused on TE modes. This is why I did the first frustum replicating what I thought was the frustum sizes by Yang and the Chinese, it wasn't the right dimensions we found out. This second is a design of mine focusing on a TE012 mode and there are many modes laying right beside of it well within the envelope of the operating range of the magnetron. I built it to be very stable in thermal expansion issues so I can focus on the interactive modes in the magnetron envelope. I believe it's not one single mode that causes the unique actions but the 5 or so modes right around TE012, it is its nature for this frequency and frustum configuration to not be stable and interact with other modes.

This is what interests me, that shifting interwave mode actions. Dr. Rodel is seeing some of the forces being released in his stress calculations and simply they wouldn't be acting the way they do unless we had a sequence of mode generation and collapse. And in all of this forming and decaying Betty Crocker blender mess are the extraordinary forces of the  evanescent waves, so maybe down the line when we have a good looking visual animation we can somehow setup a filter to just look at the evanescent actions in the frustum.

And honestly the current visual well... how do I say... is very yuck.

Anyway thanks for the help and if you wouldn't mind point me to the script for paraview I'd be thankful.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/06/2015 11:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421583#msg1421583">Quote from: Mulletron on 09/01/2015 02:32 AM</a>
Long shot here, but I was reading up on how squeezed light can be generated and I found that one way is via nonlinear frequency mixing. I think I saw evidence of frequency mixing a few months ago by accident. Guess I pretty much have to bust out the test equipment again now to confirm.

http://physics.stackexchange.com/questions/83/how-is-squeezed-light-produced
https://en.wikipedia.org/wiki/Nonlinear_optics#Nonlinear_optical_processes

Anyway, there's some literature out there about using squeezed vacuum for propulsion which is interesting.
http://www.researchgate.net/publication/258317790_Preliminary_Theorectical_Considerations_for_Getting_Thrust_via_Squeezed_Vacuum

http://www.researchgate.net/publication/234887561_Extraction_of_Thrust_from_Quantum_Vacuum_Using_Squeezed_Light

Results of search for second or third harmonic generation is null. There is no support found for any harmonic generation by the frustum in my possession (no dielectric insert) in the low power regime. Input power was 0dbm.

Screenshot 10 shows spectrum analyzer with sweep generator attached (no frustum in between). Sweeper set from 700-2700mhz (between markers 1&2). Spectrum analyzer span from well below frustum cutoff to max range of gear (600-6700mhz). Harmonic generation between markers 3&4 are from the sweeper.

Screenshot 11 shows same but with sweep generator feeding frustum and spectrum analyzer on frustum sample port. Harmonic generation is the same.

So my empty copper can isn't showing any evidence of nonlinear optical behavior. High power remains unexplored. Would be interesting if one could purposely introduce this kind of behavior to see what happens.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/06/2015 11:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423451#msg1423451">Quote from: Mulletron on 09/06/2015 11:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421583#msg1421583">Quote from: Mulletron on 09/01/2015 02:32 AM</a>
Long shot here, but I was reading up on how squeezed light can be generated and I found that one way is via nonlinear frequency mixing. I think I saw evidence of frequency mixing a few months ago by accident. Guess I pretty much have to bust out the test equipment again now to confirm.

http://physics.stackexchange.com/questions/83/how-is-squeezed-light-produced
https://en.wikipedia.org/wiki/Nonlinear_optics#Nonlinear_optical_processes

Anyway, there's some literature out there about using squeezed vacuum for propulsion which is interesting.
http://www.researchgate.net/publication/258317790_Preliminary_Theorectical_Considerations_for_Getting_Thrust_via_Squeezed_Vacuum

http://www.researchgate.net/publication/234887561_Extraction_of_Thrust_from_Quantum_Vacuum_Using_Squeezed_Light

Results of search for second or third harmonic generation is null. There is no support found for any harmonic generation by the frustum in my possession (no dielectric insert) in the low power regime. Input power was 0dbm.

Screenshot 10 shows spectrum analyzer with sweep generator attached (no frustum in between). Sweeper set from 700-2700mhz (between markers 1&2). Spectrum analyzer span from below cutoff to max range (600-6700mhz). Harmonic generation between markers 3&4 are from the sweeper.

Screenshot 11 shows same but with sweep generator feeding frustum and spectrum analyzer on frustum sample port. Harmonic generation is the same.

So my empty copper can isn't showing any evidence of nonlinear optical behavior. High power remains unexplored. Would be interesting if one could purposely introduce this kind of behavior to see what happens.
What mode were you trying to get in your frustum?
Copper Frustum modes
Frank Davies NASA/JSC/EP5
2/6/2014

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/06/2015 11:42 PM
@Shell
Not trying for any specific mode in that test. Just looking for harmonics being generated. But anyway, each of those peaks on the left side of screenshot 11 is a resonance that corresponds to a mode. Which peak is what mode is anybody's guess.

Edit:
It is pretty neat how my mode peaks loosely match up with the mode spectrum from Eagleworks in your pic above. I previously identified two modes, TM212 and TM311(with the help of Rodal *) to use for testing which fall within frequencies that I can generate at home without the help of this whiz bang test equipment.

* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1353372#msg1353372
* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1352878#msg1352878
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/07/2015 12:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423442#msg1423442">Quote from: SeeShells on 09/06/2015 10:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423431#msg1423431">Quote from: Eer on 09/06/2015 09:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423426#msg1423426">Quote from: SeeShells on 09/06/2015 08:14 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
It should be quite interesting to run to see if the large plate position of the loop helps or hinders a TE mode generation. Don't expect a huge Q, EW didn't in their loops.

May I ask why we are going with this other software for postprocessing the CSV time slices?

I've been looking at Paraview to do some postprocessing, have you or anyone else here have any feedback on it as a post processor on the csv files?

Today I'm staying out of the lab, need the break and my house needs cleaning, washing done, and I need to cook something other than a TV dinner. Maybe some fried chicken and mashed potatoes with fresh roasted corn on the cob, does a body good.... :D So between loads I'm looking at Paraview.

Shell

I'm working with paraview, too - it's able to read the h5 files directly, if you use a script I've found to create the xdmf descriptor file that tells paraview how to parse the h5 file.  Let me know if I can research anything for you with it, and I'll see what I can figure out.

PNG file generation has been problematic due to difficulties figuring out what acceptable scaling factors and contour shape algorithms folks prefer to use.  Seems to involve different, and sometimes conflicting, alternatives - tradeoffs between visually appealing, sufficient dynamic range to be able to see different levels and recognize them, and the ability to compare multple related images if they're not scaled the same way ...

Visualization is, I'm convinced, more of a graphic art than a representational science.
I want to thank you for your work and help.

And sadly (or not) I'm a very visual lady, stupid patterns. ;) Some here are not as much and that's the issue.

I don't particularly care to see the lowest artifacts that meep can generate, especially if it's on a sliding scale, seeing the lowest artifacts make little sense in the frustum.  I've been looking for mode generation, traveling modes, and how they decay and where. And especially I'm focused on TE modes. This is why I did the first frustum replicating what I thought was the frustum sizes by Yang and the Chinese, it wasn't the right dimensions we found out. This second is a design of mine focusing on a TE012 mode and there are many modes laying right beside of it well within the envelope of the operating range of the magnetron. I built it to be very stable in thermal expansion issues so I can focus on the interactive modes in the magnetron envelope. I believe it's not one single mode that causes the unique actions but the 5 or so modes right around TE012, it is its nature for this frequency and frustum configuration to not be stable and interact with other modes.

This is what interests me, that shifting interwave mode actions. Dr. Rodel is seeing some of the forces being released in his stress calculations and simply they wouldn't be acting the way they do unless we had a sequence of mode generation and collapse. And in all of this forming and decaying Betty Crocker blender mess are the extraordinary forces of the  evanescent waves, so maybe down the line when we have a good looking visual animation we can somehow setup a filter to just look at the evanescent actions in the frustum.

And honestly the current visual well... how do I say... is very yuck.

Anyway thanks for the help and if you wouldn't mind point me to the script for paraview I'd be thankful.
Okay... Visuals ... Yuck. Got that.  Question though ... Did you look at the folder link, or just the three I attached?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/07/2015 12:45 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423455#msg1423455">Quote from: Mulletron on 09/06/2015 11:42 PM</a>
@Shell
Not trying for any specific mode in that test. Just looking for harmonics being generated. But anyway, each of those peaks on the left side of screenshot 11 is a resonance that corresponds to a mode. Which peak is what mode is anybody's guess.

Edit:
It is pretty neat how my mode peaks loosely match up with the mode spectrum from Eagleworks in your pic above. I previously identified two modes, TM212 and TM311(with the help of Rodal *) to use for testing which fall within frequencies that I can generate at home without the help of this whiz bang test equipment.

* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1353372#msg1353372
* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1352878#msg1352878
Let's say I take a 1KHz signal and look at it on the SA, what do I see? A peak at 1KHZ? What if I modulate it? FM or AM or both at the same time? What rolls out of a magnetron? AM and FM and zero of close to point crossovers. It's a beautiful mess of additive and subtractive interference.

If I take that 1KHz signal and run it for 16 cycles, but in the center at the 8th cycle flip phases right at the zero cross over point. Insert it into a frustum. Now all of a sudden I've generated a whole line of odd harmonics and little is left of the 1KHZ but if I look at it on the Oscope I'll see the 1KHz and cross over... weird huh?

What I'm trying to say, your harmonics could be buried across the SA sample spectrum and you wouldn't be able to see it on the SA. This is what I'm trying to look for in the varying mode generations within the meep analysis for every mode change there is a frequency and phase shifting more likely introduced by harmonic patterns within the broadband RF into that asymmetrical multi-tuned cavity. Meep is about the only way I can think of seeing them.  I guess you could setup a kind of a selective comb filter on the maggie as it's feed into the Waveguide to coax but you also could do a neat thing that X_Ray thought of and setup a trap within the frustum to attenuate the frequencies you didn't want (only after you figured out the ones you wanted) and were causing a heavy loss of Q.

Just throwing out thoughts here.

Shell

PS: The fried chicken and taters and corn were wonderful.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/07/2015 12:48 AM
********
Okay... Visuals ... Yuck. Got that.  Question though ... Did you look at the folder link, or just the three I attached?
********

Folder link? You lost me... let me look again.

Shell

Missed them. But got it thx!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/07/2015 01:35 AM
A very impressive lecture on RF cavities. Gets good around slide 40.

http://uspas.fnal.gov/materials/10MIT/Lecture6.pdf

and all the other ones:
https://www.google.it/search?q=resonant+cavities+site:uspas.fnal.gov&ie=utf-8&oe=utf-8&gws_rd=cr&ei=GevsVcT_K8a3a_yjv6AE
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/07/2015 01:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423442#msg1423442">Quote from: SeeShells on 09/06/2015 10:23 PM</a>
Anyway thanks for the help and if you wouldn't mind point me to the script for paraview I'd be thankful.

The script is from http://comments.gmane.org/gmane.comp.science.electromagnetism.meep.general/5041 and is found in the scripts/ directory as Formatting.sh under meeper-files/

The png files were created using plot2.py and a driver script.  plot2.py is in the scripts directory, too.

Here's the link to meeper-files, in case you don't have it ready to hand:
https://drive.google.com/open?id=0B527OOY4hxdZfldTN2FoVm5SRDZ2MHFJYmhaM2ZFcXVEeklpd3NnTy1RUUtnS3d1YllCWGc

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/07/2015 01:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423462#msg1423462">Quote from: SeeShells on 09/07/2015 12:45 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423455#msg1423455">Quote from: Mulletron on 09/06/2015 11:42 PM</a>
@Shell
Not trying for any specific mode in that test. Just looking for harmonics being generated. But anyway, each of those peaks on the left side of screenshot 11 is a resonance that corresponds to a mode. Which peak is what mode is anybody's guess.

Edit:
It is pretty neat how my mode peaks loosely match up with the mode spectrum from Eagleworks in your pic above. I previously identified two modes, TM212 and TM311(with the help of Rodal *) to use for testing which fall within frequencies that I can generate at home without the help of this whiz bang test equipment.

* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1353372#msg1353372
* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1352878#msg1352878
Let's say I take a 1KHz signal and look at it on the SA, what do I see? A peak at 1KHZ? What if I modulate it? FM or AM or both at the same time? What rolls out of a magnetron? AM and FM and zero of close to point crossovers. It's a beautiful mess of additive and subtractive interference.

If I take that 1KHz signal and run it for 16 cycles, but in the center at the 8th cycle flip phases right at the zero cross over point. Insert it into a frustum. Now all of a sudden I've generated a whole line of odd harmonics and little is left of the 1KHZ but if I look at it on the Oscope I'll see the 1KHz and cross over... weird huh?

What I'm trying to say, your harmonics could be buried across the SA sample spectrum and you wouldn't be able to see it on the SA. This is what I'm trying to look for in the varying mode generations within the meep analysis for every mode change there is a frequency and phase shifting more likely introduced by harmonic patterns within the broadband RF into that asymmetrical multi-tuned cavity. Meep is about the only way I can think of seeing them.  I guess you could setup a kind of a selective comb filter on the maggie as it's feed into the Waveguide to coax but you also could do a neat thing that X_Ray thought of and setup a trap within the frustum to attenuate the frequencies you didn't want (only after you figured out the ones you wanted) and were causing a heavy loss of Q.

Just throwing out thoughts here.

Shell

PS: The fried chicken and taters and corn were wonderful.

Do you think I should try modulation while looking for harmonic generation? I can do am, fm, 1khz square wave, psk, scalar. Would it be worth it?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/07/2015 02:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423473#msg1423473">Quote from: Mulletron on 09/07/2015 01:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423462#msg1423462">Quote from: SeeShells on 09/07/2015 12:45 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423455#msg1423455">Quote from: Mulletron on 09/06/2015 11:42 PM</a>
@Shell
Not trying for any specific mode in that test. Just looking for harmonics being generated. But anyway, each of those peaks on the left side of screenshot 11 is a resonance that corresponds to a mode. Which peak is what mode is anybody's guess.

Edit:
It is pretty neat how my mode peaks loosely match up with the mode spectrum from Eagleworks in your pic above. I previously identified two modes, TM212 and TM311(with the help of Rodal *) to use for testing which fall within frequencies that I can generate at home without the help of this whiz bang test equipment.

* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1353372#msg1353372
* http://forum.nasaspaceflight.com/index.php?topic=36313.msg1352878#msg1352878
Let's say I take a 1KHz signal and look at it on the SA, what do I see? A peak at 1KHZ? What if I modulate it? FM or AM or both at the same time? What rolls out of a magnetron? AM and FM and zero of close to point crossovers. It's a beautiful mess of additive and subtractive interference.

If I take that 1KHz signal and run it for 16 cycles, but in the center at the 8th cycle flip phases right at the zero cross over point. Insert it into a frustum. Now all of a sudden I've generated a whole line of odd harmonics and little is left of the 1KHZ but if I look at it on the Oscope I'll see the 1KHz and cross over... weird huh?

What I'm trying to say, your harmonics could be buried across the SA sample spectrum and you wouldn't be able to see it on the SA. This is what I'm trying to look for in the varying mode generations within the meep analysis for every mode change there is a frequency and phase shifting more likely introduced by harmonic patterns within the broadband RF into that asymmetrical multi-tuned cavity. Meep is about the only way I can think of seeing them.  I guess you could setup a kind of a selective comb filter on the maggie as it's feed into the Waveguide to coax but you also could do a neat thing that X_Ray thought of and setup a trap within the frustum to attenuate the frequencies you didn't want (only after you figured out the ones you wanted) and were causing a heavy loss of Q.

Just throwing out thoughts here.

Shell

PS: The fried chicken and taters and corn were wonderful.

Do you think I should try modulation while looking for harmonic generation? I can do am, fm, 1khz square wave, psk, scalar. Would it be worth it?
I'd do a simple one first, a square wave will give you components of odd-integer harmonic and then do a sinusoidal and compare the two in your SA.

How were you planning to excite your dielectric material?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/07/2015 04:00 AM
That work about swimming through spacetime seems similar to other stuff I've read about gravitomagnetic fields from rotating masses.

We haven't spent much time discussing the motion of charged particles in response to the time varying electromagnetic fields of various modes.

https://youtu.be/Gkfwc4Uzgss
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/07/2015 07:39 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423451#msg1423451">Quote from: Mulletron on 09/06/2015 11:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1421583#msg1421583">Quote from: Mulletron on 09/01/2015 02:32 AM</a>
Long shot here, but I was reading up on how squeezed light can be generated and I found that one way is via nonlinear frequency mixing. I think I saw evidence of frequency mixing a few months ago by accident. Guess I pretty much have to bust out the test equipment again now to confirm.

http://physics.stackexchange.com/questions/83/how-is-squeezed-light-produced
https://en.wikipedia.org/wiki/Nonlinear_optics#Nonlinear_optical_processes

Anyway, there's some literature out there about using squeezed vacuum for propulsion which is interesting.
http://www.researchgate.net/publication/258317790_Preliminary_Theorectical_Considerations_for_Getting_Thrust_via_Squeezed_Vacuum

http://www.researchgate.net/publication/234887561_Extraction_of_Thrust_from_Quantum_Vacuum_Using_Squeezed_Light

Results of search for second or third harmonic generation is null. There is no support found for any harmonic generation by the frustum in my possession (no dielectric insert) in the low power regime. Input power was 0dbm.

Screenshot 10 shows spectrum analyzer with sweep generator attached (no frustum in between). Sweeper set from 700-2700mhz (between markers 1&2). Spectrum analyzer span from well below frustum cutoff to max range of gear (600-6700mhz). Harmonic generation between markers 3&4 are from the sweeper.

Screenshot 11 shows same but with sweep generator feeding frustum and spectrum analyzer on frustum sample port. Harmonic generation is the same.

So my empty copper can isn't showing any evidence of nonlinear optical behavior. High power remains unexplored. Would be interesting if one could purposely introduce this kind of behavior to see what happens.

The levels of intermodulation products generated in the frustum (without dielectric) and associated waveguide and coaxials, are certainly very low and not accessible to your Spectrum Analyser without a preliminary power amplification.
Passive Intermodulation Product (PIMP) can be generated for example at Waveguide Flange location where metal-metal contact occurs with contamination or oxydation presence.
This phenomena is well known in Space Communication Payloads where, by coupling between Transmit and Receive RF paths, an intermodulation product of the transmit channels (generally of order 5, 7, 9 ...) can fall in their receive bandwidth. Mitigation of this effect relies on:

- A proper choice of the Receive/Transmit frequency plan to ensure for exemple that no 3th or 5th intermodulation product can fall in the receive band.
- Quality assurance control on the choice of metals and cleanless of surfaces in contact.
- Use of waveguide flange design ensuring a high mechanical pressure.
- Avoid of coaxial cable in some sensitive situation.

But if intermodulation products play a role in the EMDrive phenomena  (2nd harmonic ?) they are certainly due to the Active Intermodulation occuring in the magnetron itself and not to the very low level PIMP.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/07/2015 08:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd

Thanks very much for the information. Do you refer to the articles:"Polarizable Vacuum (PV) and the Schwarzschild Solution", "Polarizable Vacuum and the Reissner-Nordstrom Solution" ?

Are these Schwarzschild and Reissner-Nordstrom Solutions compatible with the need of an horizon of causality for the Transactional interpretation of instantaneous action of Inertia Force ( “advanced” wave propagating backward in time) ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/07/2015 08:51 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/07/2015 09:25 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422639#msg1422639">Quote from: Rodal on 09/03/2015 10:31 PM</a>
Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.

Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert.   Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum.

I think your statements are too much dogmatic. James Woodward considers that a variety of different physical systems can be imagined that store internal energy during accelerations and so that in principle, several options for exploring Mach effects should be available to us even if the use of capacitors offer the best efficiency .
Simple macroscopic mechanical systems can do the job but, however, aren’t good candidates for the production of Mach effects at an adequate level, since the rate at which internal energy changes can be affected is quite limited. What we want are systems where the time-derivatives can be made quite large. In terms of practical apparatus, that means that we are going to be looking at systems involving electromagnetism. There are several electromagnetic energy storage devices – capacitors, inductors, and batteries. Since we are looking for fast transient effects, batteries will have difficulties to follow. Inductors store energy in the magnetic field, and to put some of this energy into an accelerating material medium, we would need to provide the inductor with some core material with, preferably, a high permeability. Although a system using magnetic energy storage in some high permeability medium is plainly feasible, capacitors have several features that make them preferable to inductors.

So you cannot say (and for sure James Woodward does not say) that other approaches than the use of capacitor are unable to generate a mass variation predicted by the Mach effect whatever its  level.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kdhilliard on 09/07/2015 11:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422639#msg1422639">Quote from: Rodal on 09/03/2015 10:31 PM</a>
Prof. Dr. James Woodward, ...

Folks here might be interested in a Space Show program from last week where David Livingston recorded a tour of Dr. Woodward's Cal St. Fullerton lab, hosted by his Mach effect co-researcher, Dr. Heidi Fearn.

  Show description: http://thespaceshow.com/detail.asp?q=2545
  Direct link to audio: http://archived.thespaceshow.com/shows/2545-BWB-2015-09-03.mp3
  Show's blog entry: https://thespaceshow.wordpress.com/2015/09/04/kathy-lueders-dr-heidi-fearn-thursday-9-3-15/

This is not a normal Space Show program with callers, etc. because of David's attendance at AIAA Space 2015, but instead is a pair of interview segments.  He interviews Kathy Lueders, NASA's Commercial Crew Program Manager, from 06:50 - 51:40.  The segment with Heidi Fearn runs from 51:45 through the end at 1:45:15, and is introduced from 02:10 - 06:40.

~Kirk

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/07/2015 12:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423514#msg1423514">Quote from: Mezzenile on 09/07/2015 09:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422639#msg1422639">Quote from: Rodal on 09/03/2015 10:31 PM</a>
Prof. Dr. James Woodward, it is my understanding, is of the opinion that the only way that any propulsion out of the EM Drive could be justified using his Machian theory is if the EM Drive contains a dielectric insert as used by NASA in their experiments.

Therefore, the experiments performed by RFMWGUY, as well as the latest experiments and designs of Shaywer, and the experiments of Yang and Tajmar, for example cannot result in space propulsion according to Prof. Woodward's theory since all these experiments do not include any dielectric insert.   Prof. Woodward, as I understand it, maintains that an EM Drive tested without a dielectric insert cannot obtain any thrust whatsoever for space propulsion because such thrust is precluded by what Prof. Woodward calls "THE LAW" in capital letters: the law of conservation of momentum.

I think your statements are too much dogmatic....
I think you have not yet discussed these matters with Prof. Woodward, to seek his opinion on whether he agrees with your rendition of his theory for Shawyer's EM Drive without a dielectric. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/07/2015 01:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423522#msg1423522">Quote from: Rodal on 09/07/2015 12:08 PM</a>
I think you have not yet discussed these matters with Prof. Woodward, to seek his opinion on whether he agrees with your rendition of his theory for Shawyer's EM Drive without a dielectric.
Oh but I am not in a position to propose a theory explaining the EMDrive phenomena. I am just looking for the possible differences between successful experiments (Shawyer, Chinese, German ...) and other non conclusive experiments based on the same principle. The idea to look for the presence or not of the second harmonic is an empirical borrow to the approach of Woodward. I have nothing against the use of dielectric in RF cavities design, but it seems well that some successful experiments don't need dielectric to give measurable thrust. So other(s) parameter(s) should be looked for to explain the differences between supposed honest test results.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/07/2015 02:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423421#msg1423421">Quote from: SeeShells on 09/06/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Quite an interesting wave pattern.
Back from a short break...nope...I will not make a comment about an EM Vortex looking pattern ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/07/2015 02:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423542#msg1423542">Quote from: Mezzenile on 09/07/2015 01:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423522#msg1423522">Quote from: Rodal on 09/07/2015 12:08 PM</a>
I think you have not yet discussed these matters with Prof. Woodward, to seek his opinion on whether he agrees with your rendition of his theory for Shawyer's EM Drive without a dielectric.
Oh but I am not in a position to propose a theory explaining the EMDrive phenomena. I am just looking for the possible differences between successful experiments (Shawyer, Chinese, German ...) and other non conclusive experiments based on the same principle. The idea to look for the presence or not of the second harmonic is an empirical borrow to the approach of Woodward. I have nothing against the use of dielectric in RF cavities design, but it seems well that some successful experiments don't need dielectric to give measurable thrust. So other(s) parameter(s) should be looked for to explain the differences between supposed honest test results.
Fair enough, but I am still in the mode of eliminating faulty results such as thermal lift and getting higher resolution on downward movement. This will take some time and $$. once measurement is where I want it, I move back to the frustum. First, characterize resonance and tune for 2.45ghz if needed. A dielectric will help tune, but it could also induce movement based on outgassing at high temp. Recall EW melted some plastic hardware during testing. Guess dielectric pucks are one of my last mods to consider.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/07/2015 02:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423545#msg1423545">Quote from: rfmwguy on 09/07/2015 02:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423421#msg1423421">Quote from: SeeShells on 09/06/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Quite an interesting wave pattern.
Back from a short break...nope...I will not make a comment about an EM Vortex looking pattern ;)

heheheh, you with me big guy? So you like the loop?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/07/2015 05:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423548#msg1423548">Quote from: SeeShells on 09/07/2015 02:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423545#msg1423545">Quote from: rfmwguy on 09/07/2015 02:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423421#msg1423421">Quote from: SeeShells on 09/06/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Quite an interesting wave pattern.
Back from a short break...nope...I will not make a comment about an EM Vortex looking pattern ;)

heheheh, you with me big guy? So you like the loop?

Shell

Before I get to my point, I thought I'd just mention a misspeak in the above. With h5topng images, the number of pixels ratio go with resolution as (100/250)2 since the image is 2 dimensional. (For resolution going from 250 to 100.)

Now, the image is correct. Much clearer images will be forthcoming. The field patterns spiral out from the loop because electricity flows around the loop at a finite speed creating fields as it flows. This same characteristic is true for dipole antennas although not true for a meep simulated line source that I have been calling a dipole. The meep line source is not a dipole at all. It is a line with all points simultaneously excited. In the real world, electric charge moving in a wire radiate fields as the charge moves to and fro, there is nothing simultaneous about it on that scale.

That means that we need to think again about what previous meep data actually means and the difference in the EM field excitation patterns between antennas and wave guides.  I'll speculate that meep will calculate much lower Q values when the cavity is excited by a model of a real-world antenna.

You all know more antenna theory than I do, but for the uninformed like me, here is an easy example -reference.

http://electronics.stackexchange.com/questions/73998/how-antenna-radiateshow-currents-flows-through-wire (http://electronics.stackexchange.com/questions/73998/how-antenna-radiateshow-currents-flows-through-wire)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/07/2015 05:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423587#msg1423587">Quote from: aero on 09/07/2015 05:27 PM</a>
... The meep line source is not a dipole at all. It is a line with all points simultaneously excited. In the real world, electric charge moving in a wire radiate fields as the charge moves to and fro, there is nothing simultaneous about it on that scale.... I'll speculate that meep will calculate much lower Q values when the cavity is excited by a model of a real-world antenna...
Are you planning to run a "model of a real world" straight antenna for comparison with the "Meep line source"?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/07/2015 05:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/07/2015 06:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423507#msg1423507">Quote from: Mezzenile on 09/07/2015 08:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd

Thanks very much for the information. Do you refer to the articles:"Polarizable Vacuum (PV) and the Schwarzschild Solution", "Polarizable Vacuum and the Reissner-Nordstrom Solution" ?

Are these Schwarzschild and Reissner-Nordstrom Solutions compatible with the need of an horizon of causality for the Transactional interpretation of instantaneous action of Inertia Force ( “advanced” wave propagating backward in time) ?

Yes, those are Joe Depp's papers. They are not long and do not cover the aspects you are referring to. They are simply alternative solutions (corrections) to Puthoff's PV Model. PM me if you want to read the JBIS submission.

Regarding inertia, IMO all that is needed is doppler shift to account for it.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/07/2015 06:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423591#msg1423591">Quote from: Rodal on 09/07/2015 05:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423587#msg1423587">Quote from: aero on 09/07/2015 05:27 PM</a>
... The meep line source is not a dipole at all. It is a line with all points simultaneously excited. In the real world, electric charge moving in a wire radiate fields as the charge moves to and fro, there is nothing simultaneous about it on that scale.... I'll speculate that meep will calculate much lower Q values when the cavity is excited by a model of a real-world antenna...
Are you planning to run a "model of a real world" straight antenna for comparison with the "Meep line source"?

If there is sufficient interest on NSF for me to set aside other tasks we want to have worked. But first I need to at least generate some usable results with the loop antenna so that my modelling approach can be vetted.

I guess next we need to decide whether or not line source antenna models are actually of any use to us. Line source antennas should be fine for radiation in the far field, but everything inside the frustums are near field. At least, some mix of near and far field.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/07/2015 06:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/07/2015 06:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423597#msg1423597">Quote from: deltaMass on 09/07/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: birchoff on 09/07/2015 06:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423597#msg1423597">Quote from: deltaMass on 09/07/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Sounds like the question mez asks should be directed back at him as; Is there any experimental observation covered by GR that he doesn't thing the PV interpretation can account for?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/07/2015 07:02 PM
Then PV is an empty suit. GR can do it all.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: birchoff on 09/07/2015 07:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423611#msg1423611">Quote from: deltaMass on 09/07/2015 07:02 PM</a>
Then PV is an empty suit. GR can do it all.

It can from a purely theoretical perspective. And if we could get engineers to think in terms of GR then PV would not be necessary. From my time spent following this thread and MET's I have a sneaking suspicion that if Field propulsion technologies and FTL travel can be proved directly in GR. We would still be better off giving the engineering team a cheat sheet that meshes better with the tools and concepts they are already intimately familiar with. Instead of asking them to relearn their interpretation of reality. As Long as PV cannot express things expressly forbidden by GR we are good.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/07/2015 07:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423597#msg1423597">Quote from: deltaMass on 09/07/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/07/2015 07:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423617#msg1423617">Quote from: Rodal on 09/07/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423597#msg1423597">Quote from: deltaMass on 09/07/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Teach someone who knows how to do Differential Geometry how to do PV and we'll find out. I saw a Schwarszchild metric in Prof. Wisdom's paper. Since this metric is identical in PV, I suspect the results are identical too. Unfortunately, Diff. Geometry is at the limit of my mathematical abilities. So I'm not even going to try and prove it to anyone. I encourage others with more formidable math skills than I, to give it a shot.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/07/2015 07:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423587#msg1423587">Quote from: aero on 09/07/2015 05:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423548#msg1423548">Quote from: SeeShells on 09/07/2015 02:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423545#msg1423545">Quote from: rfmwguy on 09/07/2015 02:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423421#msg1423421">Quote from: SeeShells on 09/06/2015 07:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423405#msg1423405">Quote from: aero on 09/06/2015 06:48 PM</a>
I made one more debug run, reducing the resolution from 250 to 100. For frequency ~ 5.0 GHz  (fsi = 4.99e9) loop parameters are:
start making a loop antenna
 Number of points, NP = 113.0
 half wave length meep = 0.10013108149632599 loop diameter meep = 0.18
 loop circumference meep = 0.5654866776461628
 periods around the loop = 2.823731998075501
 meep frequency = 4.993454505116336
Loop antenna created


If there is a bug maybe I'll see it after I post this.
Unfortunately, the image scales with resolution the number of pixels ratio as 100/250, in this case.
Quite an interesting wave pattern.
Back from a short break...nope...I will not make a comment about an EM Vortex looking pattern ;)

heheheh, you with me big guy? So you like the loop?

Shell

Before I get to my point, I thought I'd just mention a misspeak in the above. With h5topng images, the number of pixels ratio go with resolution as (100/250)2 since the image is 2 dimensional. (For resolution going from 250 to 100.)

Now, the image is correct. Much clearer images will be forthcoming. The field patterns spiral out from the loop because electricity flows around the loop at a finite speed creating fields as it flows. This same characteristic is true for dipole antennas although not true for a meep simulated line source that I have been calling a dipole. The meep line source is not a dipole at all. It is a line with all points simultaneously excited. In the real world, electric charge moving in a wire radiate fields as the charge moves to and fro, there is nothing simultaneous about it on that scale.

That means that we need to think again about what previous meep data actually means and the difference in the EM field excitation patterns between antennas and wave guides.  I'll speculate that meep will calculate much lower Q values when the cavity is excited by a model of a real-world antenna.

You all know more antenna theory than I do, but for the uninformed like me, here is an easy example -reference.

http://electronics.stackexchange.com/questions/73998/how-antenna-radiateshow-currents-flows-through-wire (http://electronics.stackexchange.com/questions/73998/how-antenna-radiateshow-currents-flows-through-wire)
A good referance aero.
http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/loop.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/07/2015 10:38 PM
A million years or so ago our ancestors discovered that banging two rocks together made fire and chipped flints for a fine cutting edge. At this point in the process we are doing something that's as old as humanity and one of the finer gifts we have. When we learned to hit a rock on another rock and think, damn this is a sharp rock! I'll do it again, it doesn't work and he mashes his fingers! Do it again, with a different rock. Do it thousands of times, mash the hell out of fingers... and finally through the process of elimination and generations of mashed fingers our ancestors figured out a way to make fire and sharp flint and slice steaks for their BBQ grills.

It took us a long time but I think we have gotten better at it, that process of elimination and that is where we are now, mashing fingers. Fire and cooking sliced steaks brought us out of the dirt of the savannas to reach for and touch the moon and planets. We are still banging things together, but in multibillion dollar particle accelerators, somethings never change and somethings do.

Understanding the why something works may take a long time, it took years to figure out why a photon was a wave and a particle or how fracture mechanics work in he real world. Not understanding the EM Drive doesn't mean it doesn't work, it doesn't mean the effect isn't real, it means it simply isn't understood. That's what will take time.

I applaud everyone that keeps an open mind and simply says I just don't know.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aceshigh on 09/08/2015 01:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
The fact that March is a co-author of this article is interesting as he is himself willing to found an explanation of the Shawyer's EMDrive in term of Woodward's work:

Paul March however has, for a long time already, thought that White's QVF and Mach Effect are two sides of the same coin. If Paul March had not been believing in QVF he would not be working with Dr. White, I think.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/08/2015 01:46 AM
I am feeling a bit of excitement as, I suspect, I have convinced myself that (that I know what I am talking about) and that there is a method that (I have discussed earlier) that would work for electromagnetic propulsion.  It is describable, fairly simple, and it should be possible to convince others in the field.  Some time was needed to convince myself but I now understand a bit better why it should work.  The forces should be as large as two magnets attracting if done right but the forces should point in the same direction (unidirectional).  This should work if only one of the opposing force is eliminated (static electric or magnetic).  It isn't exactly Shawer's EM drive but as we don't yet fully understand his drive I suspect there is a remote possibility it could be related.  Then again maybe other theoretical effects would be related too. 

There should be an advantage to using the simplicity of cylindrical cavities I suspect and this method does that (simplicity in understanding).  There also appears to be a simple way of tuning and even controlling the phase inside the cavities.  Should I continue to elaborate or is the general consensus that it is impossible? 

It does depend on there being a light-speed limit to information, and if we can't agree on that then I am not sure it would work. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 09/08/2015 02:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423617#msg1423617">Quote from: Rodal on 09/07/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Someone will also have to design a very small machine to test General Relativity by swimming.

If it works I wonder if it can be turned into a practical method of space propulsion by using a billion arms?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/08/2015 02:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423704#msg1423704">Quote from: dustinthewind on 09/08/2015 01:46 AM</a>
I am feeling a bit of excitement as, I suspect, I have convinced myself that (that I know what I am talking about) and that there is a method that (I have discussed earlier) that would work for electromagnetic propulsion.  It is describable, fairly simple, and it should be possible to convince others in the field.  Some time was needed to convince myself but I now understand a bit better why it should work.  The forces should be as large as two magnets attracting if done right but the forces should point in the same direction (unidirectional).  This should work if only one of the opposing force is eliminated (static electric or magnetic).  It isn't exactly Shawer's EM drive but as we don't yet fully understand his drive I suspect there is a remote possibility it could be related.  Then again maybe other theoretical effects would be related too. 

There should be an advantage to using the simplicity of cylindrical cavities I suspect and this method does that (simplicity in understanding).  There also appears to be a simple way of tuning and even controlling the phase inside the cavities.  Should I continue to elaborate or is the general consensus that it is impossible? 

It does depend on there being a light-speed limit to information, and if we can't agree on that then I am not sure it would work.

Have you worked out the full integral of the Maxwell force density? Where all values of E & H are functions of x,y,z,t and t-t' retarded fields, in whatever coordinates you choose. Then integrate that over the volume of both halves. If you are left with a non-zero result, then you could convince anyone. Without that, we're in the same boat.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/08/2015 02:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423712#msg1423712">Quote from: WarpTech on 09/08/2015 02:28 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423704#msg1423704">Quote from: dustinthewind on 09/08/2015 01:46 AM</a>
I am feeling a bit of excitement as, I suspect, I have convinced myself that (that I know what I am talking about) and that there is a method that (I have discussed earlier) that would work for electromagnetic propulsion.  It is describable, fairly simple, and it should be possible to convince others in the field.  Some time was needed to convince myself but I now understand a bit better why it should work.  The forces should be as large as two magnets attracting if done right but the forces should point in the same direction (unidirectional).  This should work if only one of the opposing force is eliminated (static electric or magnetic).  It isn't exactly Shawer's EM drive but as we don't yet fully understand his drive I suspect there is a remote possibility it could be related.  Then again maybe other theoretical effects would be related too. 

There should be an advantage to using the simplicity of cylindrical cavities I suspect and this method does that (simplicity in understanding).  There also appears to be a simple way of tuning and even controlling the phase inside the cavities.  Should I continue to elaborate or is the general consensus that it is impossible? 

It does depend on there being a light-speed limit to information, and if we can't agree on that then I am not sure it would work.

Have you worked out the full integral of the Maxwell force density? Where all values of E & H are functions of x,y,z,t and t-t' retarded fields, in whatever coordinates you choose. Then integrate that over the volume of both halves. If you are left with a non-zero result, then you could convince anyone. Without that, we're in the same boat.
Todd

I haven't done that but I guess I will make a go at this and stick my neck out.  I am going to write up a post in hopes that it is enough to convince us it's possible. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/08/2015 04:36 AM
First, in the graphic, it is expressed how the static electric effect opposes the relativistic magnetic effect, but with a diagram.  The idea is then to cancel the static electric effect by creating a current loop.  It is then pointed out how a transverse electric field in a resonating cavity might accomplish this.  A diagram is then given as to how the device might be put together.  The next graphic is the question of what is pushing the cavities.  The dipole electric field of the static magnetic field is then reviewed and it is suggested that this is what may push the cavities.  The graphics should be small in data and I hope the physical size is small enough.  You might be required to zoom in.  In summary I expect the dual cavities to be propelled by each cavities observation of the other cavities dipole electric field which is the static magnetic field of the cavity.   The negative charges in motion in the cavity plate are the observers.  The dynamic magnetic field or -dB/dt = curl E (e.g. light) should be contained in the cavities I am now thinking. 

The dynamic plate on the one cavity (both cavities are in transverse electric mode [lowest]) is to frequency match with the other cavity and for phase control. 

If only the magnetic force is present then the forces should be much greater than radiation forces.  Energy should alternate between current in the cavities to light contained in the cavity then back again. 

I would expect the effect to be observed as this dipole redistribution of charge should be there as is observed when moving with respect to any current loop. [edited]

I am not sure of any magnetic field meter that could read fast enough but if one exists it would hopefully use moving current to measure such a dipole electric field (magnetic field).  If this dipole electric field exists outside the cavity and I think it should then such a meter should get a reading outside the cavity.  If this force exists outside the cavity and is delayed in time then that should confirm we can get propulsion.

I won't get into electric field tilting as it is an effect of moving towards a current, and is also part of the magnetic field, but in our case we don't have stuff moving towards the currents. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/08/2015 02:06 PM
Aero -

Thanks for the Scheme reference, it was very useful, and it appears actually quite simple to generate Scheme code to describe the position, orientation, size and length of cylindrical holes in a frustrum.

I attach two files: one is a text file which (I think) contains a fragment of Scheme code which might be pasted into a control file. The other is the excel file used to generate this code fragment. The parameters in the excel file can be varied, and the code regenerated by doing 'Save As' on the tab containing the code.

Since I've never written anything in anger in Scheme, the code is probably wrong, but at least follows the example you pointed me at. Certainly you would want to change the dimensional and other parameters if you wanted to actually use this. So what I'm giving you is mostly an extended example of what's possible.

I have constructed the holes so as to retain as much as possible of the rotational and other symmetries of the walls of the frustrum. It may already be obvious to others, but I found it interesting to note that if a mesh frustrum were constructed in the obvious way, by rolling up and joining a flat piece of regularly spaced mesh, the frustrum loses its rotational symmetry. Aside from the seam (!) the holes are not in the right places. If the mesh actually does affect the fields inside the frustrum, it might therefore be doing so in a way which impacts field symmetries.

Regards,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/08/2015 02:09 PM
PS, meant to add that if there is anything you'd like me to fix, or anything else you would like to to add/modify, just let me know.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 09/08/2015 02:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423811#msg1423811">Quote from: RERT on 09/08/2015 02:06 PM</a>
{snip}
I have constructed the holes so as to retain as much as possible of the rotational and other symmetries of the walls of the frustrum. It may already be obvious to others, but I found it interesting to note that if a mesh frustrum were constructed in the obvious way, by rolling up and joining a flat piece of regularly spaced mesh, the frustrum loses its rotational symmetry. Aside from the seam (!) the holes are not in the right places. If the mesh actually does affect the fields inside the frustrum, it might therefore be doing so in a way which impacts field symmetries.

Regards,

R.

So a 3D manufacturing process may be a better way to make the frustrum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/08/2015 02:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423815#msg1423815">Quote from: A_M_Swallow on 09/08/2015 02:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423811#msg1423811">Quote from: RERT on 09/08/2015 02:06 PM</a>
{snip}
I have constructed the holes so as to retain as much as possible of the rotational and other symmetries of the walls of the frustrum. It may already be obvious to others, but I found it interesting to note that if a mesh frustrum were constructed in the obvious way, by rolling up and joining a flat piece of regularly spaced mesh, the frustrum loses its rotational symmetry. Aside from the seam (!) the holes are not in the right places. If the mesh actually does affect the fields inside the frustrum, it might therefore be doing so in a way which impacts field symmetries.

Regards,

R.

So a 3D manufacturing process may be a better way to make the frustrum.
CAUTION: Nobody has yet shown (either theoretically, numerically or experimentally) that the small holes in RFMWGUY's build affect anything related to electromagnetic resonance.  On the contrary, a number of theoretical and experimental studies previously discussed in the thread point out that such small holes as used in RFMWGUY's build should NOT affect resonance at the experimental frequency (2.45GHz). 

What is known to strongly affect resonance, (as has been shown previously theoretically, numerically and experimentally) is the RF feed: whether by antenna (shape and placement of the antenna(s)) or by waveguide (shape and placement of waveguide).

Thus aero's time seems to be well directed and prioritized: towards modeling the antenna rather than the holes.

Actually, once aero has modelled loop antennas, the next suggested step should be to model RF feed through waveguide(s) (shape and placement of waveguide).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/08/2015 04:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423829#msg1423829">Quote from: Rodal on 09/08/2015 02:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423815#msg1423815">Quote from: A_M_Swallow on 09/08/2015 02:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423811#msg1423811">Quote from: RERT on 09/08/2015 02:06 PM</a>
{snip}
I have constructed the holes so as to retain as much as possible of the rotational and other symmetries of the walls of the frustrum. It may already be obvious to others, but I found it interesting to note that if a mesh frustrum were constructed in the obvious way, by rolling up and joining a flat piece of regularly spaced mesh, the frustrum loses its rotational symmetry. Aside from the seam (!) the holes are not in the right places. If the mesh actually does affect the fields inside the frustrum, it might therefore be doing so in a way which impacts field symmetries.

Regards,

R.

So a 3D manufacturing process may be a better way to make the frustrum.
CAUTION: Nobody has yet shown (either theoretically, numerically or experimentally) that the small holes in RFMWGUY's build affect anything related to electromagnetic resonance.  On the contrary, a number of theoretical and experimental studies previously discussed in the thread point out that such small holes as used in RFMWGUY's build should NOT affect resonance at the experimental frequency (2.45GHz). 

What is known to strongly affect resonance, (as has been shown previously theoretically, numerically and experimentally) is the RF feed: whether by antenna (shape and placement of the antenna(s)) or by waveguide (shape and placement of waveguide).

Thus aero's time seems to be well directed and prioritized: towards modeling the antenna rather than the holes.

Actually, once aero has modelled loop antennas, the next suggested step should be to model RF feed through waveguide(s) (shape and placement of waveguide).

@RERT -
That looks interesting. Now if one of the meepers with free time would like to incorporate your Scheme code into the NSF-1701 geometry that is available on the wiki I believe, it should make an interesting image. A couple of pointers for anyone who takes up the challenge.

1 - Use the meep/Scheme "Include" capability to add the code file into the control file after it makes the metal cone and before it makes the air cone.
2 - Use the (material metal) in place of the copper model for the frustum. The metal material makes good images but the copper model does not image at all.
3 - Set the lattice to 2 dimensional, run meep, continuous mode for 0 time.
4 - Use h5topng to make an image of the 2-D cavity. That is, image the file, eps-00...00.h5.  It's not a projection but better than what you can find in 3-D.
5 - Let us all know what it looks like.

As for me doing the above - no - not for some time - Dr. Rodal is correct when he points out that correct antenna and RF feed into the cavities are known to be important factors for all frustums, mesh, solid or ceramic. I'm making progress there and I must continue to maintain my focus.

I do applaud your versatility in applying Excel to write Scheme, that's quite a feat in its own right.

aero

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/08/2015 04:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423710#msg1423710">Quote from: A_M_Swallow on 09/08/2015 02:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423617#msg1423617">Quote from: Rodal on 09/07/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Someone will also have to design a very small machine to test General Relativity by swimming.

If it works I wonder if it can be turned into a practical method of space propulsion by using a billion arms?

Could you put it on a chip?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/08/2015 04:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423710#msg1423710">Quote from: A_M_Swallow on 09/08/2015 02:22 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423617#msg1423617">Quote from: Rodal on 09/07/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Someone will also have to design a very small machine to test General Relativity by swimming.

If it works I wonder if it can be turned into a practical method of space propulsion by using a billion arms?
Wisdom's paper ends with a numerical result concerning a deformable 1 metre object at or near Earth's surface. Each stroke buys you ~10-23 m displacement. In order to amplify the effect, two obvious strategies come up: repetition in space and repetition in time. Mechanical concerns restrict the update frequency - there's a big question mark against applying THz to an object of that size, no matter how light, I think (someone might prove me wrong using extended nanoscale structures though). How spatial amplification might work is not clear to me. Certainly "a billion arms" doesn't do it for me.

This later work is interesting, in that it predicts inertial modification using a similar technique
http://arxiv.org/abs/0706.2909v2

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/08/2015 06:23 PM
NSF-1701 update - So long galinstan hello 10' feed of filament, ground and HV wires. Laser displacement sensor mounted on tripod, goodbye laser pointer. Controller and display ordered today for lds. Couple of vertical aluminum bars added to Doc's oil dampener to retard horizontal oscillations...works great. Powered up fine with long feed wires. Droops and loops seem to flex easily. Miller time...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/08/2015 06:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423619#msg1423619">Quote from: WarpTech on 09/07/2015 07:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423617#msg1423617">Quote from: Rodal on 09/07/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423597#msg1423597">Quote from: deltaMass on 09/07/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Teach someone who knows how to do Differential Geometry how to do PV and we'll find out. I saw a Schwarszchild metric in Prof. Wisdom's paper. Since this metric is identical in PV, I suspect the results are identical too. Unfortunately, Diff. Geometry is at the limit of my mathematical abilities. So I'm not even going to try and prove it to anyone. I encourage others with more formidable math skills than I, to give it a shot.
Todd

Please find attached a Venn diagram that Prof. Dr. Jim Woodward sent out over the past weekend that summarizes these issues:  Mainstream Physics (Quantum Mechanics and General Relatiivity), then PV and Mach Effect, etc.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/08/2015 06:50 PM
About arcing in cavities
https://en.wikipedia.org/wiki/Kilpatrick_limit
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/08/2015 07:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423890#msg1423890">Quote from: deltaMass on 09/08/2015 06:50 PM</a>
About arcing in cavities
https://en.wikipedia.org/wiki/Kilpatrick_limit

The exact solution for the least-square optimization of the data ( https://en.wikipedia.org/wiki/Kilpatrick_limit ) of the maximum Electric field E given by the Kilpatrick Limit, for a given frequency (in GHz) is:

E (MV/m) = 4.25/ProductLog[0.17211188221619098/Sqrt[frequency(GHz)]]

Where ProductLog gives the principal solution for w in z=we^w (the ProductLog function is also called the Lambert Function https://en.wikipedia.org/wiki/Lambert_W_function )

(Diagram_of_the_real_branches_of_the_Lambert_W_function.png)

So, solving for

frequency = 2.45 GHz = 2450 MHz

we get

E = 42.6964 MV/m

for the maximum electric field E achievable (limited by RF breakdown, as tested experimentally in the 1950s by W. D. Kilpatrick)

********************************************************************************

while for NASA Eagleworks

frequency = 1.9372 GHz = 1937.2 MHz

we get

E = 38.3921 MV/m

********************************************************************************

while for Shawyer Flight Thruster

frequency = 3.85 GHz = 3850 MHz

we get

E = 52.5343 MV/m

********************************************************************************

while for Cannae Superconducting

frequency = 1.047 GHz = 1047 MHz

we get

E = 29.2223 MV/m

********************************************************************************

while for Baby EM Drive (Aachen, Germany)

frequency = 24.1 GHz

we get

E = 125.402 MV/m

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/08/2015 07:26 PM
I have made runs with the loop antenna. csv data and png view files for 3 runs are here.

https://drive.google.com/folderview?id=0B1XizxEfB23tcEVRLTlXR2JxZXM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tcEVRLTlXR2JxZXM&usp=sharing)

Thirty two cycle runs with the final 14 one-tenth cycle time slices presented.

These runs are using SeeShells' Crazy-Eddie 2 (CE2) frustum model and Rodal's 0.054 meter diameter loop antenna. Two of the runs place the loop at 0.054 meters from the small end of the frustum, while the other run has the loop placed 0.054 meters from the big end.

Finding resonance for this frustum/antenna combination was a chore. Using resolution = 100 (which has always worked well in the past), Harminv invariably calculated resonant frequency at 2.500 GHz and Q - O(300-500). I ran and uploaded one set of data with this frequency - I was loosing hope. Fortunately I decided to check convergence and was able to complete Harminv runs with resolution = 200. I was amazed.

Doubling resolution, using resolution = 200, Harminv calculated resonant frequency = 2.47065 GHz, differing by only 10's of Hz for the big end or small end antenna location. And the stupid low Q values went away. With the loop antenna toward the big end of the frustum, calculated Q ~= 6 million, and with the antenna toward the small end, calculated Q ~= 28 million. While these values are not representative of a real world metal construction, they do indicate that the cavity will resonate strongly at the drive frequency of 2.47065 GHz. I uploaded data sets for these two cases  at the link above.

Any readers with antenna knowledge, please evaluate the png views with an eye toward fidelity of the model field patterns compared to real antenna field patterns. I know that the frustum complicates this evaluation but thanks.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/08/2015 08:03 PM
Congratulations and strong clapping !

(tumblr_inline_mkucbv7tUX1qz4rgp.gif)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: birchoff on 09/08/2015 11:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423884#msg1423884">Quote from: Rodal on 09/08/2015 06:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423619#msg1423619">Quote from: WarpTech on 09/07/2015 07:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423617#msg1423617">Quote from: Rodal on 09/07/2015 07:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423604#msg1423604">Quote from: WarpTech on 09/07/2015 06:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423597#msg1423597">Quote from: deltaMass on 09/07/2015 06:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423594#msg1423594">Quote from: WarpTech on 09/07/2015 05:55 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423510#msg1423510">Quote from: deltaMass on 09/07/2015 08:51 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423172#msg1423172">Quote from: WarpTech on 09/05/2015 06:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423097#msg1423097">Quote from: Mezzenile on 09/05/2015 07:24 AM</a>
...

Now I agree with you that the Puthof's Polarizable Vacuum theory cannot be a replacement for General Relativity and its endorsement of Mach (not March ! ;)) intuition on the origin of inertia. It was also; I would say; the view of Puthof himself who clearly wrote in 1999 that the Polarizable Vacuum theory was not yet in a positon to explain both gravitational radiation and frame-dragging effects (base of Mach ideas on inertia incorporation in General Relativity).

The work of Puthoff, Joe Depp, Riccardo Storti and myself, have resolved these issues with PV by 2005. The PV warp drive is frame dragging in PV just as it is in GR. It turns out that the metric coefficients of GR are "equivalent" to a variable refractive index tensor, composed of QV interactions with matter.

What I have come to understand clearly, is that the differences between PV and GR are simply a matter of how one interprets the math. Space-time curvature of empty vacuum VS interactions of matter with the QV. I have developed a Quantum model for PV that works well enough for engineering purposes. If even 1 millionth of the work done in the name of GR were done for PV, all this would be obvious and text book trivia, but history has lead thousands of people to work on GR. Where, only a handful of mostly engineers have even grasped the power of PV as a foundation for understanding GR. More people should study it, as it really does lead to new ideas that fit within the GR framework, simply by re-interpreting the physical interaction of matter & metric.

FYI: I am still waiting for JBIS to give me any review or comments on my Electromagnetic Quantum Vacuum Warp Drive paper that I submitted last January. Which shows how the QV model of PV is used to re-interpret GR and better understand what is needed to go FTL. You can find related work on my RG page.
Todd
Can PV make any experimentally verifiable predictions different to those made by mainstream physics,  that would earn it a place at the table? I think not, otherwise it would be big news.

Hypothetically, it predicts that the Hubble expansion "red shift" could be (partly) due to our rulers contracting as the universe runs out of energy. All it takes is for 1 meter to contract by 6.8 nanometers/century, as the driving power of the ZPF runs down in the present, relative to the distant past we view through our telescope, to account for the Hubble expansion.
Todd
Yes, but I did ask for something experimentally verifiable. If everything, including our measuring sticks, is changing then how could we know? Can you devise any experiment to test any of PV's unique predictions?

The thing is, it is not unique. I can predict the same thing using GR, resulting from variation of the metric coefficient. So it wouldn't solve anything. Again, PV is simply an alternative interpretation of GR. The math is identical, so the predictions are also identical. Until we have a verifiable "accepted" model of Quantum Gravity, both PV and GR are classical theories which are complimentary interpretations of the observable data. My QG model, is an engineering tool that works within the parameters I need it to work. That's all.
Todd

Prof. Wisdom proved that an astronaut can swim in space just by using his arms (albeit with an extremely small stroke) using General Relativity.  Can the Puthoff PV theory show the same result ? (that an astronaut can swim in space just by using his arms)

Teach someone who knows how to do Differential Geometry how to do PV and we'll find out. I saw a Schwarszchild metric in Prof. Wisdom's paper. Since this metric is identical in PV, I suspect the results are identical too. Unfortunately, Diff. Geometry is at the limit of my mathematical abilities. So I'm not even going to try and prove it to anyone. I encourage others with more formidable math skills than I, to give it a shot.
Todd

Please find attached a Venn diagram that Prof. Dr. Jim Woodward sent out over the past weekend that summarizes these issues:  Mainstream Physics (Quantum Mechanics and General Relatiivity), then PV and Mach Effect, etc.

Just curious was this posted somewhere public... Always looking for more information on Woodwards progress.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/09/2015 12:14 AM
All wave guide experts out there, what can you tell me about the shape of the  EM fields in a wave guide excited by a noisy magnetron. How long should the wave guide be, its height and width? But mostly, what do the EM field patterns look like?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/09/2015 12:17 AM
Update:

I spent the weekend polishing the cylinder and it looks much better (couldn't get some of the bigger scratches out unfortunately). However it definitely improved the VNA plots. Today we tested the attached resonance, seems to be matched very well at 2.434 GHz. But we still don't have a spectrum analysis of our magnetron, so we aren't sure how the power is distributed and how that changes over time. 

The EMF strips arrived to hopefully improve electrical connection between the waveguide and cylinder without the messy Ox Gard. We heard some arcing when the magnetron fired up which seemed to stop (or at least quiet down) as the test continued. We definitely have some deflection but it could easily be due to asymmetric current flow to ground. The x deflection is actually a torque on the cylinder (clockwise if looking from above). This may also be from misalignment of the cylinder axis. The y deflection is in the right direction (towards the dielectric)  and we calculated the force causing it is about 1 mN. Unfortunately our noise level was fairly high so we will need to repeat this test early in the morning when we can get less noise. I'll post the raw data if anyone is interested.

The biggest problem is obtaining symmetric current flow: we've shown that we can get significant deflections on resonance with asymmetric grounding which disappear off resonance. When fields don't build up surface currents are too small to cause a disturbance. We may need to weld our movable plate near a resonant position and manufacture some tuning fixture. However at high power we fear a tuning screw would not work (would probably arc). Are there any other relatively easy analog tuning methods for high power out there?

The simulations are coming along, I've modeled a coax to waveguide to frustum with a VSWR of 1.15 and quality of ~22,000. Changing the length of the coax shifts the resonant frequency (non-linearly which surprised me) but maintains the quality. One question I have yet to answer: how can I model a coax to waveguide bought from a manufacturer without their proprietary information? (i.e. penetration depth and back wall distance) I was able to determine dimensions that give me a VSWR of 1.2 (their maximum quoted value) and used the dimensions for an RG142 coax.

https://www.youtube.com/watch?v=yrsK76Ywyu8

Instead I could model the system with a plane wave excitation, but how do I know the phase of the wave exiting the purchased waveguide? Maybe we should attempt to manufacture this waveguide on our own?
I've emailed the manufacturer back with these questions, perhaps I am missing something or over analyzing...

We've come to the conclusion that a microwave oven magnetron is far from ideal for this application. (As many of you have said before) The wide bandwidth and unpredictable shifting max power make designing any high quality resonator near impossible. Using a circulator could deliver power at the right frequency but would still filter out the majority of the power. And then we don't know how much power is actually being delivered to the cavity... NWPU must have overcome this challenge with a higher tolerance magnetron with a more stable frequency distribution.   

Anyone have any suggestions, comments, questions?

-Kurt
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/09/2015 02:00 AM
So you have an asymmetrical current flow abd a frustum that wants to move up and rotate to the right.  If you flipped it would it rotate to the left?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/09/2015 02:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424058#msg1424058">Quote from: SteveD on 09/09/2015 02:00 AM</a>
So you have an asymmetrical current flow abd a frustum that wants to move up and rotate to the right.  If you flipped it would it rotate to the left?


The frustum is the next design. The cylinder experiences an x displacement and y displacement, which, because it is measured by a reflected laser from an angled mirror that is *perpendicular to the laser, means the cylinder torqued (if looking from above). We could move the PSD and laser to the other side, and flip it, but I don't think that will change anything. We could try other wire orientations, but they are twisted pretty tightly together, so I'm not sure that would change anything.

*An assumption that we have yet to verify, could easily be off by several degrees.   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 02:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423883#msg1423883">Quote from: rfmwguy on 09/08/2015 06:23 PM</a>
NSF-1701 update - So long galinstan hello 10' feed of filament, ground and HV wires. Laser displacement sensor mounted on tripod, goodbye laser pointer. Controller and display ordered today for lds. Couple of vertical aluminum bars added to Doc's oil dampener to retard horizontal oscillations...works great. Powered up fine with long feed wires. Droops and loops seem to flex easily. Miller time...
Really looking good rfmwguy. You should be very excited to crank this tar baby up.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/09/2015 03:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424078#msg1424078">Quote from: SeeShells on 09/09/2015 02:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423883#msg1423883">Quote from: rfmwguy on 09/08/2015 06:23 PM</a>
NSF-1701 update - So long galinstan hello 10' feed of filament, ground and HV wires. Laser displacement sensor mounted on tripod, goodbye laser pointer. Controller and display ordered today for lds. Couple of vertical aluminum bars added to Doc's oil dampener to retard horizontal oscillations...works great. Powered up fine with long feed wires. Droops and loops seem to flex easily. Miller time...
Really looking good rfmwguy. You should be very excited to crank this tar baby up.

Shell
Yes I am. Focus has been on improving test stand and resolution. I will characterize thermal lift, then move towards frustum tuning. Might even try to match frustum to the +/- 40 mhz bandwidth the maggy has rather than a single freq resonance. This normally involves 2 cavities loosely coupled, zeros at beginning and end of bandwidth. A single cavity will be a challenge. Not yet sure how to get 2 resonance zero poles out of a single cavity...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 03:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423903#msg1423903">Quote from: aero on 09/08/2015 07:26 PM</a>
I have made runs with the loop antenna. csv data and png view files for 3 runs are here.

https://drive.google.com/folderview?id=0B1XizxEfB23tcEVRLTlXR2JxZXM&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tcEVRLTlXR2JxZXM&usp=sharing)

Thirty two cycle runs with the final 14 one-tenth cycle time slices presented.

These runs are using SeeShells' Crazy-Eddie 2 (CE2) frustum model and Rodal's 0.054 meter diameter loop antenna. Two of the runs place the loop at 0.054 meters from the small end of the frustum, while the other run has the loop placed 0.054 meters from the big end.

Finding resonance for this frustum/antenna combination was a chore. Using resolution = 100 (which has always worked well in the past), Harminv invariably calculated resonant frequency at 2.500 GHz and Q - O(300-500). I ran and uploaded one set of data with this frequency - I was loosing hope. Fortunately I decided to check convergence and was able to complete Harminv runs with resolution = 200. I was amazed.

Doubling resolution, using resolution = 200, Harminv calculated resonant frequency = 2.47065 GHz, differing by only 10's of Hz for the big end or small end antenna location. And the stupid low Q values went away. With the loop antenna toward the big end of the frustum, calculated Q ~= 6 million, and with the antenna toward the small end, calculated Q ~= 28 million. While these values are not representative of a real world metal construction, they do indicate that the cavity will resonate strongly at the drive frequency of 2.47065 GHz. I uploaded data sets for these two cases  at the link above.

Any readers with antenna knowledge, please evaluate the png views with an eye toward fidelity of the model field patterns compared to real antenna field patterns. I know that the frustum complicates this evaluation but thanks.
BigEng run Dr. Rodel's 2.47GHz Ex,Ey,Ez in a gif loop.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/09/2015 05:02 AM
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 05:19 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Left Field on 09/09/2015 05:54 AM
EM Corkscrew Drive?

(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRh-3q7ynFfvSzJbyoy2oL0SzSOo5Vhu4BMmE0ShEHglSyTutskqsuvvnk6jQ)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: deltaMass on 09/09/2015 07:08 AM
This requires some care because, as is well known, spacetime has a right-hand thread.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 09/09/2015 10:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424020#msg1424020">Quote from: zellerium on 09/09/2015 12:17 AM</a>
Anyone have any suggestions, comments, questions?

-Kurt

What are the dimensions of the frustum and the waveguide in your video?

One thing that keeps surprising me is how big the waveguides are WRT their attached frustum (same problem with Tajmar's experiment, where this issue is even greater); while Shawyer's waveguide always seems very narrow.

Is there a reason why large standard waveguides are used (remember they can account for a large frequency range) instead of specific smaller waveguides matched with the source frequency?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 01:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424136#msg1424136">Quote from: deltaMass on 09/09/2015 07:08 AM</a>
This requires some care because, as is well known, spacetime has a right-hand thread.
 :)  Really?, in which direction is spacetime's right-handed screw oriented?  Towards a black-hole?

(2010-09-17-screw.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 02:25 PM
Cylindrical cans used as antennas

SEE ACTUAL MICROWAVES — NO MORE FAKING IT


http://hackaday.com/2015/09/08/see-actual-microwaves-no-more-faking-it/


https://www.youtube.com/watch?v=rqCus4ER1d0
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 03:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424016#msg1424016">Quote from: aero on 09/09/2015 12:14 AM</a>
All wave guide experts out there, what can you tell me about the shape of the  EM fields in a wave guide excited by a noisy magnetron. How long should the wave guide be, its height and width? But mostly, what do the EM field patterns look like?
Here is a primer.
http://www.ibiblio.org/kuphaldt/electricCircuits/AC/AC_14.html

Visuals and some tech
Added https://www.youtube.com/watch?v=wUdaRwjg5ZM
https://www.cst.com/Academia/Examples/Hollow-Rectangular-Waveguide

http://www.rfcafe.com/references/electrical/NEETS-Modules/NEETS-Module-11-1-11-1-20.htm

The EM waves from a magnetron injected into a waveguide will look very similar as all fall within the resonance of the cavity. A waveguide to Coax feed the cavity is quite short and depending on the antenna used sets the frequencies allowed to pass. If you inject from a magnetron directly into frustum through a Zmatched hole in the top like the proposal from March's design at EW you're a little better off.

A couple of observations I've come up with is that if we inject from a waveguide into the frustum sidewalls the mode shapes will deform from the incoming wave and reflection from the other side of the cavity and mode generation losses will occur. I saw this with the Dresden test and the one just posted.

If you're looking to try setting up a waveguide into a frustum. Do a dual 180 out of phase sidewall matched set of guides for injection, or better yet do a injection like Mr. March's into the top of the frustum.

Unless you have a specific request then I'll try to help as well.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/09/2015 03:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424160#msg1424160">Quote from: flux_capacitor on 09/09/2015 10:52 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424020#msg1424020">Quote from: zellerium on 09/09/2015 12:17 AM</a>
Anyone have any suggestions, comments, questions?

-Kurt

What are the dimensions of the frustum and the waveguide in your video?

One thing that keeps surprising me is how big the waveguides are WRT their attached frustum (same problem with Tajmar's experiment, where this issue is even greater); while Shawyer's waveguide always seems very narrow.

Is there a reason why large standard waveguides are used (remember they can account for a large frequency range) instead of specific smaller waveguides matched with the source frequency?

The frustum is designed to resonate with a TE 011 mode and has r_top = 1.3 r_bottom = 4.3 and h =8 inches. The waveguide is a standard WR340 because we plan to buy the waveguide to coax adapter from a manufacturer.
I would rather make the after-aperture waveguide smaller so that more energy is contained in the frustum, but I'll need to play with the simulation more to find the right dimensions.

Hasn't Shawyer had some resonators that operated at higher frequency?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 09/09/2015 04:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424233#msg1424233">Quote from: zellerium on 09/09/2015 03:26 PM</a>
Hasn't Shawyer had some resonators that operated at higher frequency?

Yes, the latest known as the "Flight Thruster" designed for Boeing. It was powered by 3.85 GHz travelling-wave tube amplifiers (TWTAs). But former ones used standard 2.45 GHz magnetrons.

However my recollection may be affected by Shawyer's drawings showing very narrow waveguides, while actual pictures of his thrusters show bigger waveguides (and sometimes, coax inputs).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 05:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424281#msg1424281">Quote from: flux_capacitor on 09/09/2015 04:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424233#msg1424233">Quote from: zellerium on 09/09/2015 03:26 PM</a>
Hasn't Shawyer had some resonators that operated at higher frequency?

Yes, the latest known as the "Flight Thruster" designed for Boeing. It was powered by 3.85 GHz travelling-wave tube amplifiers (TWTAs). But former ones used standard 2.45 GHz magnetrons.

However my recollection may be affected by Shawyer's drawings showing very narrow waveguides, while actual pictures of his thrusters show bigger waveguides (and sometimes, coax inputs).

This is a picture of the first "Experimental" thruster by Shawywer, being excited by a waveguide:

(feasibility3.jpg)

frequency = 2.45 GHz

dielectric insert with relative permittivity =38

reported Q = 5900

reported force = 16 mN

reported Input Power = 850 W

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 05:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424233#msg1424233">Quote from: zellerium on 09/09/2015 03:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424160#msg1424160">Quote from: flux_capacitor on 09/09/2015 10:52 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424020#msg1424020">Quote from: zellerium on 09/09/2015 12:17 AM</a>
Anyone have any suggestions, comments, questions?

-Kurt

What are the dimensions of the frustum and the waveguide in your video?

One thing that keeps surprising me is how big the waveguides are WRT their attached frustum (same problem with Tajmar's experiment, where this issue is even greater); while Shawyer's waveguide always seems very narrow.

Is there a reason why large standard waveguides are used (remember they can account for a large frequency range) instead of specific smaller waveguides matched with the source frequency?

The frustum is designed to resonate with a TE 011 mode and has r_top = 1.3 r_bottom = 4.3 and h =8 inches. The waveguide is a standard WR340 because we plan to buy the waveguide to coax adapter from a manufacturer.
I would rather make the after-aperture waveguide smaller so that more energy is contained in the frustum, but I'll need to play with the simulation more to find the right dimensions.

Hasn't Shawyer had some resonators that operated at higher frequency?
What was your RF source? A magnetron, powered by what?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/09/2015 06:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424121#msg1424121">Quote from: SeeShells on 09/09/2015 05:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.
It was pretty clear that the mode shape would looks asymmetric and that it would rotate around the central axis.

This pattern is a result of the long loop antenna with several half wavelength (different signs/ vector of the field along the loop wire)... That was what i am talking about during the discussion about.
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416734#msg1416734
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423000#msg1423000
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418157#msg1418157
... ::)
Compare the field pattern with the pure loop antenna gif

Nevertheless it looks nice aero, great work! High Q looks good :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/09/2015 06:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424121#msg1424121">Quote from: SeeShells on 09/09/2015 05:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.

I though Rodal wanted the antenna near the large base.  Gif seems to show antenna near the small base.  Maybe animations of both setups would be useful?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/09/2015 07:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424323#msg1424323">Quote from: SteveD on 09/09/2015 06:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424121#msg1424121">Quote from: SeeShells on 09/09/2015 05:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.

I though Rodal wanted the antenna near the large base.  Gif seems to show antenna near the small base.  Maybe animations of both setups would be useful?
https://drive.google.com/folderview?id=0B1XizxEfB23tSUtybjhCN1ZlMzQ&usp=sharing&tid=0B1XizxEfB23tcEVRLTlXR2JxZXM

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/09/2015 07:11 PM
Future thought - Use of full power, broadband magnetrons might be more suitable than we may think. Caveat? A resonant cavity whose return loss is 25.0dB or better over a +/- 40 MHz BW around 2.45 Ghz. Sound impossible? Nope. Wait...there's more.

But I'm not ready to say yet...Only because I have not fully visualized it and put it to paper. This I will do.

While this will not affect my current build at all, I am thinking this is a bigger leap than trying to tune and track around a higher Q, single freq resonance; and it is supercooled-abled. IOW, it is using the broad power spectrum of a magnetron without tuning/tracking difficulties.

I might call this a Gen 3 Drive...then again, I might call it NSF-1701A.  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 07:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424316#msg1424316">Quote from: X_RaY on 09/09/2015 06:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424121#msg1424121">Quote from: SeeShells on 09/09/2015 05:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.
It was pretty clear that the mode shape would looks asymmetric and that it would rotate around the central axis.

This pattern is a result of the long loop antenna with several half wavelength (different signs/ vector of the field along the loop wire)... That was what i am talking about during the discussion about.
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416734#msg1416734
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423000#msg1423000
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418157#msg1418157
... ::)
Compare the field pattern with the pure loop antenna gif

Nevertheless it looks nice aero, great work! High Q looks good :)

Four points deserve to be made, and not ignored:

1) Previous runs showed that the amount of time of these two runs is NOT long enough to get anywhere close to a  steady, well-formed mode.  Examination of the csv files shows that it takes 64 to 128 cycles to get close to well-formed modes, for more symmetric geometries (Yang/Shell at 6 degrees).  Therefore present observations based on this early state may be premature.  Longer runs to 128 cycles would be required to know the non-transient shape of the modes.

2) The runs for the Yang/Shell geometry have to be taken under consideration that the cone half-angle in that case is much smaller, only 6 degrees, hence the Yang/Shell geometry is much more like a cylinder than a truncated cone.   This geometry has a much higher cone angle. 

3) I don't recall that the small loop run resulted in any better defined cylindrical mode.  One thing we have learnt from Meep is that it is not trivial to impose well-formed cylindrical modes, particularly of the TE type on a conical frustum

4) The png images shown for these last two runs have gone back to the multiple contour lines with recurrent colors, which do NOT allow one to ascertain the magnitude of the fields.  Furthermore, no color/numerical bar is shown to ascertain the magnitude of the fields.  Are you therefore making an assessment without knowing the magnitude of the fields ?

::)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/09/2015 07:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424334#msg1424334">Quote from: Rodal on 09/09/2015 07:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424316#msg1424316">Quote from: X_RaY on 09/09/2015 06:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424121#msg1424121">Quote from: SeeShells on 09/09/2015 05:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.
It was pretty clear that the mode shape would looks asymmetric and that it would rotate around the central axis.

This pattern is a result of the long loop antenna with several half wavelength (different signs/ vector of the field along the loop wire)... That was what i am talking about during the discussion about.
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416734#msg1416734
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423000#msg1423000
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418157#msg1418157
... ::)
Compare the field pattern with the pure loop antenna gif

Nevertheless it looks nice aero, great work! High Q looks good :)

Four points deserve to be made, and not ignored:

1) Previous runs showed that the amount of time of these two runs is NOT long enough to get anywhere close to a  steady, well-formed mode.  Examination of the csv files shows that it takes 64 to 128 cycles to get close to well-formed modes, for more symmetric geometries (Yang/Shell at 6 degrees).  Therefore present observations based on this early state may be premature.  Longer runs to 128 cycles would be required to know the non-transient shape of the modes.

2) The runs for the Yang/Shell geometry have to be taken under consideration that the cone half-angle in that case is much smaller, only 6 degrees, hence the Yang/Shell geometry is much more like a cylinder than a truncated cone.   This geometry has a much higher cone angle. 

3) I don't recall that the small loop run resulted in any better defined cylindrical mode.  One thing we have learnt from Meep is that it is not trivial to impose well-formed cylindrical modes, particularly of the TE type on a conical frustum

4) The png images shown for these last two runs have gone back to the multiple contour lines with recurrent colors, which do NOT allow one to ascertain the magnitude of the fields.  Furthermore, no color/numerical bar is shown to ascertain the magnitude of the fields.  Are you therefore making an assessment without knowing the magnitude of the fields ?

::)
1) Sounds good i hope you are right with that.
2) Yes. May be some kind of averaging(sign dependent?) looks similar to the searched pattern in this configuration?
3) Yes the little loop around the central axis leads to worse coupling and tiny Q  :-\
What do you think about the following design with short loops?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/09/2015 07:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424305#msg1424305">Quote from: SeeShells on 09/09/2015 05:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424233#msg1424233">Quote from: zellerium on 09/09/2015 03:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424160#msg1424160">Quote from: flux_capacitor on 09/09/2015 10:52 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424020#msg1424020">Quote from: zellerium on 09/09/2015 12:17 AM</a>
Anyone have any suggestions, comments, questions?

-Kurt

What are the dimensions of the frustum and the waveguide in your video?

One thing that keeps surprising me is how big the waveguides are WRT their attached frustum (same problem with Tajmar's experiment, where this issue is even greater); while Shawyer's waveguide always seems very narrow.

Is there a reason why large standard waveguides are used (remember they can account for a large frequency range) instead of specific smaller waveguides matched with the source frequency?

The frustum is designed to resonate with a TE 011 mode and has r_top = 1.3 r_bottom = 4.3 and h =8 inches. The waveguide is a standard WR340 because we plan to buy the waveguide to coax adapter from a manufacturer.
I would rather make the after-aperture waveguide smaller so that more energy is contained in the frustum, but I'll need to play with the simulation more to find the right dimensions.

Hasn't Shawyer had some resonators that operated at higher frequency?

What was your RF source? A magnetron, powered by what?

Shell

The simulation power source is a plane wave in a coax, which is how the EM Pro demo does a coax to waveguide adapter. This plane wave has an impedance line drawn across it from the inside of the outer conductor to the outside of the inner conductor. It is also defined as a 1 W modal power feed as opposed to a 50 Ohm voltage source, which are the only two FEM excitations available (also something I have seen in demo videos online). 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 07:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424339#msg1424339">Quote from: X_RaY on 09/09/2015 07:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424334#msg1424334">Quote from: Rodal on 09/09/2015 07:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424316#msg1424316">Quote from: X_RaY on 09/09/2015 06:15 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424121#msg1424121">Quote from: SeeShells on 09/09/2015 05:19 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424115#msg1424115">Quote from: aero on 09/09/2015 05:02 AM</a>
We are looking at a plane perpendicular to the z axis as the fields pass through. It looks like the fields rotate but I speculate it is more like a cork-screw pattern.

I wonder what the x or y views look like.

Orbital angular momentum comes to mind.
It was pretty clear that the mode shape would looks asymmetric and that it would rotate around the central axis.

This pattern is a result of the long loop antenna with several half wavelength (different signs/ vector of the field along the loop wire)... That was what i am talking about during the discussion about.
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1416734#msg1416734
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423000#msg1423000
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1418157#msg1418157
... ::)
Compare the field pattern with the pure loop antenna gif

Nevertheless it looks nice aero, great work! High Q looks good :)

Four points deserve to be made, and not ignored:

1) Previous runs showed that the amount of time of these two runs is NOT long enough to get anywhere close to a  steady, well-formed mode.  Examination of the csv files shows that it takes 64 to 128 cycles to get close to well-formed modes, for more symmetric geometries (Yang/Shell at 6 degrees).  Therefore present observations based on this early state may be premature.  Longer runs to 128 cycles would be required to know the non-transient shape of the modes.

2) The runs for the Yang/Shell geometry have to be taken under consideration that the cone half-angle in that case is much smaller, only 6 degrees, hence the Yang/Shell geometry is much more like a cylinder than a truncated cone.   This geometry has a much higher cone angle. 

3) I don't recall that the small loop run resulted in any better defined cylindrical mode.  One thing we have learnt from Meep is that it is not trivial to impose well-formed cylindrical modes, particularly of the TE type on a conical frustum

4) The png images shown for these last two runs have gone back to the multiple contour lines with recurrent colors, which do NOT allow one to ascertain the magnitude of the fields.  Furthermore, no color/numerical bar is shown to ascertain the magnitude of the fields.  Are you therefore making an assessment without knowing the magnitude of the fields ?

::)
1) Sounds good i hope you are right with that.
2) Yes. May be an averaging looks like the searched pattern?
3) Yes the little loop leads to worse coupling and tiny Q :/
What do you think about the following design with short loops?

I like your design because:

1) There are a number of antennas symmetrically placed to impose some circumferential symmetry
2) The current takes a shorter amount of time to make a full round-trip in the small antennas than in the big loop, hence no overall screw effect

However, given these empirical facts:

1) NASA Eagleworks, whose work I trust to be of the highest quality, had lots of trouble exciting the TE012 mode and had to settle on exciting TM modes which were easier to excite

2)  Many experimenters decided to use waveguides (Shawyer on the first Experimental, Yang with her experiments, Shawyer again guiding Tajmar to use a waveguide) instead of antennas: they must go through the trouble of the waveguides for good reason

Hence, at some point, aero should start looking at modeling excitation via a waveguide.

It is much easier to impose the mode in a rectangular waveguide than in tapered frustum

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 08:23 PM
A number of experimental papers claim to have excited TE012 or TE013 modes in an EM Drive conical frustum.  They do so based on calculations based on simplifications (standing wave eigenvalue analysis instead of transient analysis of travelling waves), but never based on measurement.

It is to be noted that only one (1) organization (NASA) has actually verified, with an experimental measurement, the actual mode that was excited, and it was a transverse magnetic mode: TM212.

Talk is cheap.  Anybody can claim that they excited a TE mode in an EM Drive frustum.  It is noteworthy that nobody has experimentally verified it.  Until further verification a skeptical reader of these reports might as well think that a TM mode was excited instead..
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 08:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424341#msg1424341">Quote from: zellerium on 09/09/2015 07:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424305#msg1424305">Quote from: SeeShells on 09/09/2015 05:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424233#msg1424233">Quote from: zellerium on 09/09/2015 03:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424160#msg1424160">Quote from: flux_capacitor on 09/09/2015 10:52 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424020#msg1424020">Quote from: zellerium on 09/09/2015 12:17 AM</a>
Anyone have any suggestions, comments, questions?

-Kurt

What are the dimensions of the frustum and the waveguide in your video?

One thing that keeps surprising me is how big the waveguides are WRT their attached frustum (same problem with Tajmar's experiment, where this issue is even greater); while Shawyer's waveguide always seems very narrow.

Is there a reason why large standard waveguides are used (remember they can account for a large frequency range) instead of specific smaller waveguides matched with the source frequency?

The frustum is designed to resonate with a TE 011 mode and has r_top = 1.3 r_bottom = 4.3 and h =8 inches. The waveguide is a standard WR340 because we plan to buy the waveguide to coax adapter from a manufacturer.
I would rather make the after-aperture waveguide smaller so that more energy is contained in the frustum, but I'll need to play with the simulation more to find the right dimensions.

Hasn't Shawyer had some resonators that operated at higher frequency?

What was your RF source? A magnetron, powered by what?

Shell

The simulation power source is a plane wave in a coax, which is how the EM Pro demo does a coax to waveguide adapter. This plane wave has an impedance line drawn across it from the inside of the outer conductor to the outside of the inner conductor. It is also defined as a 1 W modal power feed as opposed to a 50 Ohm voltage source, which are the only two FEM excitations available (also something I have seen in demo videos online).

Well that limits you to modeling a lot of tings that could happen vs a real world. At least with meep we can do a little fudging around.

Do you have a choice of where to put your feed? End or sidewall and are you limited to a snub with just drawing a impedance line. Can you call out the bandwidth of the incoming RF? Can you change phasing of the incoming signal? Could you model a dual waveguide feed 180 degrees apart on the side walls (a mirror if you like) and change the phasing of the second input to match? This should give you a very clean TE011 mode generation.

Thoughts.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/09/2015 10:14 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424356#msg1424356">Quote from: Rodal on 09/09/2015 08:23 PM</a>
A number of experimental papers claim to have excited TE012 or TE013 modes in an EM Drive conical frustum.  They do so based on calculations based on simplifications (standing wave eigenvalue analysis instead of transient analysis of travelling waves), but never based on measurement.

It is to be noted that only one (1) organization (NASA) has actually verified, with an experimental measurement, the actual mode that was excited, and it was a transverse magnetic mode: TM212.

Talk is cheap.  Anybody can claim that they excited a TE mode in an EM Drive frustum.  It is noteworthy that nobody has experimentally verified it.  Until further verification a skeptical reader of these reports might as well think that a TM mode was excited instead..
You're quite right Dr. Rodel. TE modes have been notorious to excite in a frustum and many have tried and died.

Currently aero simply cannot model where I'm at in the loop designs. I am planning on doing several loops in the top small plate. Using a quasi-loop antenna but very interesting loop configuration, that will exclude the other close modes and force the TE in the cavity. I think X_Ray and maybe Cee has an idea of what I'm going to do as they have both commented correctly on the multi-loop configuration. I think putting the loop in the center will lead to a washing machine effect which I saw in the current meep sims.

The only way that will happen is by first inserting the antennas into the small end.

I'm in the middle of the build of the frustum. When I finish it (I'll be using copper endplates for testing), I'll be doing VNA testing along with the SA to determine the effectiveness of the design with the multiple antennas and fine tune the design.

It has come to build this thing with my best engineering guess and design and fine tune.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/09/2015 10:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424362#msg1424362">Quote from: SeeShells on 09/09/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424341#msg1424341">Quote from: zellerium on 09/09/2015 07:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424305#msg1424305">Quote from: SeeShells on 09/09/2015 05:37 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424233#msg1424233">Quote from: zellerium on 09/09/2015 03:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424160#msg1424160">Quote from: flux_capacitor on 09/09/2015 10:52 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424020#msg1424020">Quote from: zellerium on 09/09/2015 12:17 AM</a>
Anyone have any suggestions, comments, questions?

-Kurt

What are the dimensions of the frustum and the waveguide in your video?

One thing that keeps surprising me is how big the waveguides are WRT their attached frustum (same problem with Tajmar's experiment, where this issue is even greater); while Shawyer's waveguide always seems very narrow.

Is there a reason why large standard waveguides are used (remember they can account for a large frequency range) instead of specific smaller waveguides matched with the source frequency?

The frustum is designed to resonate with a TE 011 mode and has r_top = 1.3 r_bottom = 4.3 and h =8 inches. The waveguide is a standard WR340 because we plan to buy the waveguide to coax adapter from a manufacturer.
I would rather make the after-aperture waveguide smaller so that more energy is contained in the frustum, but I'll need to play with the simulation more to find the right dimensions.

Hasn't Shawyer had some resonators that operated at higher frequency?

What was your RF source? A magnetron, powered by what?

Shell

The simulation power source is a plane wave in a coax, which is how the EM Pro demo does a coax to waveguide adapter. This plane wave has an impedance line drawn across it from the inside of the outer conductor to the outside of the inner conductor. It is also defined as a 1 W modal power feed as opposed to a 50 Ohm voltage source, which are the only two FEM excitations available (also something I have seen in demo videos online).

Well that limits you to modeling a lot of tings that could happen vs a real world. At least with meep we can do a little fudging around.

Do you have a choice of where to put your feed? End or sidewall and are you limited to a snub with just drawing a impedance line. Can you call out the bandwidth of the incoming RF? Can you change phasing of the incoming signal? Could you model a dual waveguide feed 180 degrees apart on the side walls (a mirror if you like) and change the phasing of the second input to match? This should give you a very clean TE011 mode generation.

Thoughts.

Shell

I know that for the FDTD simulations I can use a 50 ohm voltage source and define a waveform, however I haven't quite figured out how to do those sims well yet. For the simulations I've been running (FEM) the placement of the feed is easy to change and I could put as many excitations as necessary so long as they are on the mesh boundary. The last idea would be very interesting to see, but I don't know how easy it would be to actually create and power that system.

Luckily if we are designing it for an amplifier we don't need to worry about frequency distribution, definitely not easy to model the magnetron...
I need to keep working at it to get the FDTD sims to work well, but I still have yet to master the FEM.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/09/2015 10:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424398#msg1424398">Quote from: zellerium on 09/09/2015 10:42 PM</a>
...
I know that for the FDTD simulations I can use a 50 ohm voltage source and define a waveform, however I haven't quite figured out how to do those sims well yet. For the simulations I've been running (FEM) the placement of the feed is easy to change and I could put as many excitations as necessary so long as they are on the mesh boundary. The last idea would be very interesting to see, but I don't know how easy it would be to actually create and power that system.

Luckily if we are designing it for an amplifier we don't need to worry about frequency distribution, definitely not easy to model the magnetron...
I need to keep working at it to get the FDTD sims to work well, but I still have yet to master the FEM.
I don't quite get the differentiation you are describing between FDTD and FEM.

Meep uses the central difference method both in the space and time domains to solve transient problems.  One can use the Finite Element method in space with Finite Difference in the time domain (FDTD) to solve transient problems.  I wrote several such programs many years ago to solve very nonlinear problems.  Actually most Finite Element programs use Finite Difference methods in the time domain to solve transient problems.

Perhaps when you are referring to the Finite Element method you are referring to an eigenvalue solution using the Finite Element method ?  Is your FDTD solution using finite difference or finite elements in the space domain?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/09/2015 10:53 PM
Um can somebody explain to me why TE012 is so special?  I mean this thing is looking more and more propeller like as we go on.  For god stakes it even seems to be torquing the frustum similar to what a propeller does.  What fluid is it acting on?  I don't have the fogiest.  The swimming in space article gives me some interesting ideas, but anything dealing with physics at that level tends to come down to math, not intuition.

Ok, so basically you're trying to circularly polarize the wave and TE is better for this purpose than TM.  So why is one TE mode any better than any other?  Are you trying to circularly polarize an evanescent wave and TE012 is somehow special?  If so why the frustum?  Are we somehow generating more evanescent waves by using it?  More evanescent waves in one direction than another (greater area of the big base than the small base to generate them, would explain why the symmetrical test was a null)?  If so why on earth would an evenescent wave do something that a normal one could not?  If evenescent waves tend to be generated 1/3 wavelength from an antenna what effect does the frustum deforming the wave have?  Why Q?  Does the probability of generating an evenescent wave increase with each bounce?  Does the effect just require a highly energetic environment?

Does this paper have any bearing on the matter at hand? (Singular evanescent wave resonances) http://arxiv.org/abs/1311.3718 (http://arxiv.org/abs/1311.3718)

This thing seems to spin up (turn on delay), spin down (turn off delay) and torques to one side.  It acts like a propeller and I'm completely at a loss as to how it could be doing anything in a vacuum chambers.  My only thought is that the torquing (reported here and with Tajmar) is somehow the result of the use of a waveguide making the thing look more propeller like than it actually is.

Think I'm going to read a book and not think about EMDrives for a bit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/09/2015 11:08 PM
@6:43, see the "trapnado"

https://www.youtube.com/watch?v=wjTelKoHqUk

Do any computational electrodynamics experts out there know how to simulate the motion of a positive or negative ion inside an Emdrive excited with TE012 for example?

(xindex.php,qaction=dlattach,3Btopic=38203.0,3Battach=1064560,3Bimage.pagespeed.ic.awW3T57Q-t.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/09/2015 11:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423704#msg1423704">Quote from: dustinthewind on 09/08/2015 01:46 AM</a>
1...

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423733#msg1423733">Quote from: dustinthewind on 09/08/2015 04:36 AM</a>
2...

I am wondering if my post on this thread is too convoluted and no one feels they understand it, or if people feel they understand it but think that I don't know what I am talking about.  It does appear everyone is very busy already and so maybe I should be posting this in a separate thread?  I feel like it qualifies as a type of EM drive so maybe it should be here and just sit a bit on the back shelf?  Any suggestions?

One question I have is if anyone has measured with a Hall effect magnetic field meter (http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html), an osculating signal that decreases with 1/r^3 coming from outside the base of a resonating cavity which changes in phase with distance.  I do expect such a signal to be there in the frame of the meters moving charge.  I am not sure a meter exists that could record data fast enough though it is possible with the right design, I think.  It would at least appear as noise on a meter that was too slow. 

Are there any arguments for why it won't work? 
Are there any questions? 
Suggestions, that I should move it to a new thread? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/09/2015 11:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424404#msg1424404">Quote from: Rodal on 09/09/2015 10:52 PM</a>

I don't quite get the differentiation you are describing between FDTD and FEM.

Meep uses the central difference method both in the space and time domains to solve transient problems.  One can use the Finite Element method in space with Finite Difference in the time domain (FDTD) to solve transient problems.  I wrote several such programs many years ago to solve very nonlinear problems.  Actually most Finite Element programs use Finite Difference methods in the time domain to solve transient problems.

Perhaps when you are referring to the Finite Element method you are referring to an eigenvalue solution using the Finite Element method ?  Is your FDTD solution using finite difference or finite elements in the space domain?

Yes, the FEM solver in EMPro is an Eigenvalue method, however it is different than the pure Eigenfrequency solver (another option) which does not have a source but simply finds the resonant frequency of whatever geometry you give it.

I'm not sure the distinction between finite elements and finite difference, (both of them divide the space into small cubes where electric/magnetic fields are calculated right? )
This quote from the Keysight manual will probably clarify:
"In the FDTD approach, both space and time are divided into discrete segments. Space is
segmented into box-shaped cells, which are small compared to the wavelength. The electric fields are located on the edges of the box and the magnetic fields are positioned on the faces as shown in the figure below. This orientation of the fields is known as the Yee cell, and is the basis for FDTD."
source: http://edadownload.software.keysight.com/eedl/empro/2010/pdf/emprosim.pdf


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/10/2015 12:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424405#msg1424405">Quote from: SteveD on 09/09/2015 10:53 PM</a>
Um can somebody explain to me why TE012 is so special?  I mean this thing is looking more and more propeller like as we go on.  For god stakes it even seems to be torquing the frustum similar to what a propeller does.  What fluid is it acting on?  I don't have the fogiest.  The swimming in space article gives me some interesting ideas, but anything dealing with physics at that level tends to come down to math, not intuition.

Ok, so basically you're trying to circularly polarize the wave and TE is better for this purpose than TM.  So why is one TE mode any better than any other?  Are you trying to circularly polarize an evanescent wave and TE012 is somehow special?  If so why the frustum?  Are we somehow generating more evanescent waves by using it?  More evanescent waves in one direction than another (greater area of the big base than the small base to generate them, would explain why the symmetrical test was a null)?  If so why on earth would an evenescent wave do something that a normal one could not?  If evenescent waves tend to be generated 1/3 wavelength from an antenna what effect does the frustum deforming the wave have?  Why Q?  Does the probability of generating an evenescent wave increase with each bounce?  Does the effect just require a highly energetic environment?

Does this paper have any bearing on the matter at hand? (Singular evanescent wave resonances) http://arxiv.org/abs/1311.3718 (http://arxiv.org/abs/1311.3718)

This thing seems to spin up (turn on delay), spin down (turn off delay) and torques to one side.  It acts like a propeller and I'm completely at a loss as to how it could be doing anything in a vacuum chambers.  My only thought is that the torquing (reported here and with Tajmar) is somehow the result of the use of a waveguide making the thing look more propeller like than it actually is.

Think I'm going to read a book and not think about EMDrives for a bit.

I believe the more fundamental the mode, the the higher amplitude of resonance. Whether TE or TM will 'thrust' better is still up in the air IMO. But we do know Yang claims the TE011 mode to be the best she could simulate, and she reported the largest thrust values.

"It was found that the thruster cavity made by copper and resonating on the equivalent TE011 mode has a quality factor 320400 and generates total net EM thrust 411 mN for 1000 W 2.45 GHz incident microwave"
-Yang 2013

EW's TM212 seemed to work, but thrust to power was significantly less. And we can't forget they needed a dielectric, a mystery that still hasn't been solved. I don't know if I'd settle with Paul March's original theory that the phase modulation and amplitude modulation of the magnetron contributes to no need for a dielectric. I think it has to do with what mode was excited in EW's cavity and the need for significant field asymmetry. Perhaps the frustum shape alone can cause enough asymmetry when using fundamental modes because they span more of the tapered height. A TM 212 on the other hand does not span very much of the height so a dielectric may have been necessary to 'squish' the fields down on one side so that enough asymmetry was created for thrust. 

But take all of that with a grain of salt, I haven't spent as much time thinking about why this thing works and rather focused on how to get one to work.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/10/2015 12:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424422#msg1424422">Quote from: dustinthewind on 09/09/2015 11:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423733#msg1423733">Quote from: dustinthewind on 09/08/2015 04:36 AM</a>
...

I am wondering if my post on this thread is too convoluted and no one feels they understand it, or if people feel they understand it but think that I don't know what I am talking about.  It does appear everyone is very busy already and so maybe I should be posting this in a separate thread?  I feel like it qualifies as a type of EM drive so maybe it should be here and just sit a bit on the back shelf?  Any suggestions?

One question I have is if anyone has measured with a Hall effect magnetic field meter (http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/hall.html), an osculating signal that decreases with 1/r^3 coming from outside the base of a resonating cavity which changes in phase with distance.  I do expect such a signal to be there in the frame of the meters moving charge.  I am not sure a meter exists that could record data fast enough though it is possible with the right design, I think.  It would at least appear as noise on a meter that was too slow. 

Are there any arguments for why it won't work? 
Are there any questions? 
Suggestions, that I should move it to a new thread?

It seems like it would be possible, as you said, with fast enough data collection and a sensitive enough probe.
What would be the result of such a measurement?
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/10/2015 12:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424423#msg1424423">Quote from: zellerium on 09/09/2015 11:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424404#msg1424404">Quote from: Rodal on 09/09/2015 10:52 PM</a>

I don't quite get the differentiation you are describing between FDTD and FEM.

Meep uses the central difference method both in the space and time domains to solve transient problems.  One can use the Finite Element method in space with Finite Difference in the time domain (FDTD) to solve transient problems.  I wrote several such programs many years ago to solve very nonlinear problems.  Actually most Finite Element programs use Finite Difference methods in the time domain to solve transient problems.

Perhaps when you are referring to the Finite Element method you are referring to an eigenvalue solution using the Finite Element method ?  Is your FDTD solution using finite difference or finite elements in the space domain?

Yes, the FEM solver in EMPro is an Eigenvalue method, however it is different than the pure Eigenfrequency solver (another option) which does not have a source but simply finds the resonant frequency of whatever geometry you give it.

I'm not sure the distinction between finite elements and finite difference, (both of them divide the space into small cubes where electric/magnetic fields are calculated right? )
This quote from the Keysight manual will probably clarify:
"In the FDTD approach, both space and time are divided into discrete segments. Space is
segmented into box-shaped cells, which are small compared to the wavelength. The electric fields are located on the edges of the box and the magnetic fields are positioned on the faces as shown in the figure below. This orientation of the fields is known as the Yee cell, and is the basis for FDTD."
source: http://edadownload.software.keysight.com/eedl/empro/2010/pdf/emprosim.pdf

The Yee cell is a Finite DIfference in space domain cell.
Finite difference methods approximate the partial differential equation with finite differences at nodes (points in the domain).  Higher order finite difference methods in space need to use several nodes.

Finite Element methods divide the space domain into polygons (they don't need to be cubes, actually tetahedrons are as common or more commonly used) with a functional interpolation (usually polynomials) inside them.
Finite Element methods can be based on variational principles (although they don't need to be, some of them are based on the Galerkin method for example) and therefore have much better convergence properties than Finite Difference methods.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/10/2015 12:25 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424435#msg1424435">Quote from: zellerium on 09/10/2015 12:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424422#msg1424422">Quote from: dustinthewind on 09/09/2015 11:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423733#msg1423733">Quote from: dustinthewind on 09/08/2015 04:36 AM</a>
...
...

It seems like it would be possible, as you said, with fast enough data collection and a sensitive enough probe.
What would be the result of such a measurement?

The observation would be an osculating voltage (a wave) on the magnetic field meter towards or away from the cavity base that depends on current direction in the base of the cavity and current in the Hall effect probe.  It should be the static magnetic field (not -dB/dt) that is being observed to penetrate the cavity.  The static magnetic field really being the relativistic dipole electric field I indicate in the image of my earlier post.  (the one with the curved spokes for negative charge). 
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423733#msg1423733">Quote from: dustinthewind on 09/08/2015 04:36 AM</a>
2...

With a probe that is too slow it would appear as increased noise but osculating between a high and low voltage.  It just wouldn't have enough data points to capture the wave behavior.  A Hall effect meter would be ideal I would think.  Currents should be large with a large Q of the cavity and enough stored energy. 

If the signal travels at light speed and "if a wave form can be observed" then there should be a delay in phase with probe distance from the base.  This delayed signal should be lacking in any static electric field (no electric field is observed in the lab frame) and should be purely magnetic if the cavity is in a low Transverse Electric mode with only circulating currents.  If this is so then I suspect we can use this signal for magnetic propulsion using another cavity and the forces should be greater than radiation propulsion. (Unlike a phase antenna array which should only give radiation propulsion because of charge separation or capacitance). 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/10/2015 01:40 AM
Hey Doc, with all the recent talk about corkscrew modeling, aren't you glad I didn't wander off into an EM Vortex type analogy?

I'm very pleased with myself, holding back on my early, wild speculations about mass displacement from the center of the vortices to avoid superluminal velocities...doooh! Sorry, Doc ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/10/2015 02:40 AM
Hey guys, on some reflection I think somebody knowledgeable really needs to look at this paper. 

Singular evanescent wave resonances http://arxiv.org/ftp/arxiv/papers/1311/1311.3718.pdf (http://arxiv.org/ftp/arxiv/papers/1311/1311.3718.pdf)

Yu Guo, Zubin Jacob
(Submitted on 15 Nov 2013 (v1), last revised 17 Sep 2014 (this version, v3))

Resonators fold the path of light by reflections leading to a phase balance and thus constructive addition of propagating waves. However, amplitude decrease of these waves due to incomplete reflection or material absorption leads to a finite quality factor of all resonances. Here we report on our discovery that evanescent waves can lead to a perfect phase and amplitude balance causing an ideal Fabry-Perot resonance condition in spite of material absorption and non-ideal reflectivities. This counterintuitive resonance occurs if and only if the metallic Fabry-Perot plates are in relative motion to each other separated by a critical distance. We show that the energy needed to approach the resonance arises from the conversion of the mechanical energy of motion to electromagnetic energy. The phenomenon is similar to lasing where the losses in the cavity resonance are exactly compensated by optical gain media instead of mechanical motion. Nonlinearities and non-localities in material response will inevitably curtail any singularities however we show the giant enhancement in non-equilibrium phenomena due to such resonances in moving media.

http://arxiv.org/abs/1311.3718 (http://arxiv.org/abs/1311.3718)

Sorry but I can't help but wondering, what if you can run this process backwards?  I know I'm going to botch this but, get two plates at the critical distance and stick them so that they can't move.  Circularly polarize the signal so that it is corkscrewing into the end plate.  An evanescent wave would be generated at a 90 degree angle (am I right that with the wave corkscrewing in this would be toward the other base).  If this could be run backwards, it would seem that the closer to perfect Q the setup gets the more it would want to introduce a mechanical movement between the plates.  Let me go even further out and suggest that when the plates are of two different sizes one gains more energy in the direction of its movement that the other does in the opposite direction.

Does it conserve energy: Well I don't think you can get more energy out of something that you load into an object, minus heat, with this proposed effect.

Does it conserve momentum: Well maybe.  The waves would give up more of their energy to the baseplate generation movement in the direction of travel than the baseplate generating "drag."  That's really weird, but maybe it conserves momentum.

Does it do weird things to spacetime: um the paper proposes a "negative Poynting vector,"  I suspect that is going to do something odd (though wouldn't it be positive if the process were reversed). 

Ok it's late and I'm showing my lack of knowledge on a paper that is already pushing some theoretical boundaries.   
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 09/10/2015 09:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424433#msg1424433">Quote from: zellerium on 09/10/2015 12:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424405#msg1424405">Quote from: SteveD on 09/09/2015 10:53 PM</a>
Um can somebody explain to me why TE012 is so special?  I mean this thing is looking more and more propeller like as we go on.  For god stakes it even seems to be torquing the frustum similar to what a propeller does.  What fluid is it acting on?  I don't have the fogiest.  The swimming in space article gives me some interesting ideas, but anything dealing with physics at that level tends to come down to math, not intuition.

Ok, so basically you're trying to circularly polarize the wave and TE is better for this purpose than TM.  So why is one TE mode any better than any other?  Are you trying to circularly polarize an evanescent wave and TE012 is somehow special?  If so why the frustum?  Are we somehow generating more evanescent waves by using it?  More evanescent waves in one direction than another (greater area of the big base than the small base to generate them, would explain why the symmetrical test was a null)?  If so why on earth would an evenescent wave do something that a normal one could not?  If evenescent waves tend to be generated 1/3 wavelength from an antenna what effect does the frustum deforming the wave have?  Why Q?  Does the probability of generating an evenescent wave increase with each bounce?  Does the effect just require a highly energetic environment?

Does this paper have any bearing on the matter at hand? (Singular evanescent wave resonances) http://arxiv.org/abs/1311.3718 (http://arxiv.org/abs/1311.3718)

This thing seems to spin up (turn on delay), spin down (turn off delay) and torques to one side.  It acts like a propeller and I'm completely at a loss as to how it could be doing anything in a vacuum chambers.  My only thought is that the torquing (reported here and with Tajmar) is somehow the result of the use of a waveguide making the thing look more propeller like than it actually is.

Think I'm going to read a book and not think about EMDrives for a bit.

I believe the more fundamental the mode, the the higher amplitude of resonance. Whether TE or TM will 'thrust' better is still up in the air IMO. But we do know Yang claims the TE011 mode to be the best she could simulate, and she reported the largest thrust values.

"It was found that the thruster cavity made by copper and resonating on the equivalent TE011 mode has a quality factor 320400 and generates total net EM thrust 411 mN for 1000 W 2.45 GHz incident microwave"
-Yang 2013

EW's TM212 seemed to work, but thrust to power was significantly less. And we can't forget they needed a dielectric, a mystery that still hasn't been solved. I don't know if I'd settle with Paul March's original theory that the phase modulation and amplitude modulation of the magnetron contributes to no need for a dielectric. I think it has to do with what mode was excited in EW's cavity and the need for significant field asymmetry. Perhaps the frustum shape alone can cause enough asymmetry when using fundamental modes because they span more of the tapered height. A TM 212 on the other hand does not span very much of the height so a dielectric may have been necessary to 'squish' the fields down on one side so that enough asymmetry was created for thrust. 

But take all of that with a grain of salt, I haven't spent as much time thinking about why this thing works and rather focused on how to get one to work.

In the US patent #3,425,006 "Cavity resonator with mode discriminating means" by James Wolf, from 1969, already posted by Rodal in Thread 2 (http://forum.nasaspaceflight.com/index.php?topic=36313.msg1322038#msg1322038), it is clearly stated that TE modes are better than TM modes to achieve precise tuning and high Q factor:

Quote from: James Wolf
The TE modes are highly desirable for tunable high-Q resonators because they do not require current crossing between the outer Wall and the circular end plates of the cavity, and because the Q factor is high. These particular modes have therefore found Wide application.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/10/2015 01:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424461#msg1424461">Quote from: rfmwguy on 09/10/2015 01:40 AM</a>
Hey Doc, with all the recent talk about corkscrew modeling, aren't you glad I didn't wander off into an EM Vortex type analogy?

I'm very pleased with myself, holding back on my early, wild speculations about mass displacement from the center of the vortices to avoid superluminal velocities...doooh! Sorry, Doc ;)
There is nothing wrong in a helical wave injected into the frustum if done right. It also has nothing to do with superluminal wave velocities.

The key is to match the helical wave pattern to the one the frustum wants to generate from it's geometry. In the case of the current loop tested by meep inside the centerline of the frustum the loop generated wave patterns that were mostly subtractive to any mode generation.

Select the correct rotational pattern along with the correct cavity size it becomes a additive process instead of subtractive. Very similar to the one animation I just did, picking this mode as it's easy so see the effects of a matched frequency/helical/frustum pattern generation.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/10/2015 02:27 PM
Can anyone here convert a .skp to a GDSII?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: bprager on 09/10/2015 03:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424579#msg1424579">Quote from: SeeShells on 09/10/2015 02:27 PM</a>
Can anyone here convert a .skp to a GDSII?
You could try to convert  (http://www.file-extensions.org/convert-skp-to-dxf)to .dxf first and then  (http://en.freedownloadmanager.org/tutorials/how-to-convert-dxf-to-gdsii-with-layouteditor-2014.html)to GDSII.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/10/2015 03:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424598#msg1424598">Quote from: bprager on 09/10/2015 03:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424579#msg1424579">Quote from: SeeShells on 09/10/2015 02:27 PM</a>
Can anyone here convert a .skp to a GDSII?
You could try to convert  (http://www.file-extensions.org/convert-skp-to-dxf)to .dxf first and then  (http://en.freedownloadmanager.org/tutorials/how-to-convert-dxf-to-gdsii-with-layouteditor-2014.html)to GDSII.
I'm using the free version of sketchup which only exports in a .skp and I need a GDS to import into a EM model.
Thanks
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/10/2015 04:54 PM
Has anyone done a mathematical proof to make sure a stable TE012 is possible in a frustum at these frequencies?  We would all feel a bit silly if we spent all this time and effort trying to do something that was impossible.  (Certain ironies with the above statement and this entire project are noted).

Speaking of which, here is the dispersion measure plot from the Arecibo, Fast Radio Burst detection.  I've said elsewhere that I think its either the result of the classified project Shawyer says he was working on (very likely) or possibly somebody else using an EMDrive subject to engineering restraints we are not currently aware of (highly unlikely going to extremely unlikely if that somebody is not associated with the planet Earth).  Since I don't know the cutoff for Arecibo's equipment this is of limited value (if a full run starts at 1hz and goes all the way up to the high gammas it clearly stellar in nature).  Still, I can't help but feel that if I could, arbitrarily, pick a frequency to start poking about around with an EMDrive, somewhere in this range might bear interesting fruit.  (Paper: http://arxiv.org/abs/1404.2934 (http://arxiv.org/abs/1404.2934))
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/10/2015 05:29 PM
Follow up from that Arecibo paper, please tell me that that is not what I think it is.  Alternatively, please show me that its somebodies spy sat that we aren't suppose to know about.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 09/10/2015 07:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/10/2015 07:46 PM
I don't know what I'm doing but here is my "Magnetron/waveguide" feed.

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

I've coded a constant frequency for use as a wave length ruler, and am exciting the cavity at a variable frequency parameter, both are set to 2.47 GHz, and the constant won't change.

The dimensions are x= wl/4, z = wl/2 and the length, y = 2*wl. (constants) The x and z dimensions are then increased by 30% as I read somewhere that they should be. I hope to be able to shorten the y dimension as that length will make the meep computational lattice quite large.

The structure is excited from a rectangular plate wl/4 from the big end. The plate dimensions are yp = 0, xp = 0.9*x, zp=0.9*z (all constants) excited by the Ex component. The resulting Hz component is displayed.

I can use all the help I can get.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/10/2015 07:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424694#msg1424694">Quote from: Ricvil on 09/10/2015 07:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?

I programmed it like the receiving loop antenna on my TV set. Is that not right?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 09/10/2015 07:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424702#msg1424702">Quote from: aero on 09/10/2015 07:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424694#msg1424694">Quote from: Ricvil on 09/10/2015 07:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?

I programmed it like the receiving loop antenna on my TV set. Is that not right?

The point aero is how the loop antena model is feeded.
Sorry I need take a bus now. I will clarify the question later.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/10/2015 08:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424694#msg1424694">Quote from: Ricvil on 09/10/2015 07:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?
At low frequencies it is not important at all. But if the loop is in the dimension of the wavelength the situation is clear different. For example, if you look to smith diagram, between 0.5 and ~0.95 wavelengths the loop acts capacitive.

A standing wave at the antenna loop is only true if the antenna itself is also in resonance (exact multiple of half wavelength).
And yes in real world one have reflections at every discontinuity...

If this is not a answer to your question, please formulate a clear question. English isn't my natural language..

http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/loop.html (@Shell, thanks for this link :) )
http://www.antennenkoppler.de/achim/antenna/Impedanz_im_Smith_1.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/10/2015 08:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424636#msg1424636">Quote from: SteveD on 09/10/2015 04:54 PM</a>
Has anyone done a mathematical proof to make sure a stable TE012 is possible in a frustum at these frequencies?  We would all feel a bit silly if we spent all this time and effort trying to do something that was impossible.  (Certain ironies with the above statement and this entire project are noted).

Speaking of which, here is the dispersion measure plot from the Arecibo, Fast Radio Burst detection.  I've said elsewhere that I think its either the result of the classified project Shawyer says he was working on (very likely) or possibly somebody else using an EMDrive subject to engineering restraints we are not currently aware of (highly unlikely going to extremely unlikely if that somebody is not associated with the planet Earth).  Since I don't know the cutoff for Arecibo's equipment this is of limited value (if a full run starts at 1hz and goes all the way up to the high gammas it clearly stellar in nature).  Still, I can't help but feel that if I could, arbitrarily, pick a frequency to start poking about around with an EMDrive, somewhere in this range might bear interesting fruit.  (Paper: http://arxiv.org/abs/1404.2934 (http://arxiv.org/abs/1404.2934))

Hi, I think I saw you talking about the FRB thing on Reddit. I honestly don't understand what you are saying. Can you ELI5 it to us please?

https://www.reddit.com/r/EmDrive/comments/3jwpdi/cribbing_somebody_elses_notes/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 09/10/2015 09:46 PM

310px-TransmissionLineDefinitions.svg.png
Gaussian_Pulse_in_Transmission_Line.png
00133x01.png

See these three figures.
They shows basicaly, how a pulse travels along a transmission line.
Note the current flow on each wire of transmission line. Same amplitude, opposite signal.
Then imagine the loop antenna at the end of transmission line.
What would be the form of the currents reaching the loop antenna?
Why we are seeing only one current flux reaching the loop antenna by just one side?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424706#msg1424706">Quote from: X_RaY on 09/10/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424694#msg1424694">Quote from: Ricvil on 09/10/2015 07:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?
At low frequencies it is not important at all. But if the loop is in the dimension of the wavelength the situation is clear different. For example, if you look to smith diagram, between 0.5 and ~0.95 wavelengths the loop acts capacitive.

A standing wave at the antenna loop is only true if the antenna itself is also in resonance (exact multiple of half wavelength).
And yes in real world one have reflections at every discontinuity...

If this is not a answer to your question, please formulate a clear question. English isn't my natural language..

http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/loop.html (@Shell, thanks for this link :) )
http://www.antennenkoppler.de/achim/antenna/Impedanz_im_Smith_1.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/10/2015 10:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424700#msg1424700">Quote from: aero on 09/10/2015 07:46 PM</a>
I don't know what I'm doing but here is my "Magnetron/waveguide" feed.

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

I've coded a constant frequency for use as a wave length ruler, and am exciting the cavity at a variable frequency parameter, both are set to 2.47 GHz, and the constant won't change.

The dimensions are x= wl/4, z = wl/2 and the length, y = 2*wl. (constants) The x and z dimensions are then increased by 30% as I read somewhere that they should be. I hope to be able to shorten the y dimension as that length will make the meep computational lattice quite large.

The structure is excited from a rectangular plate wl/4 from the big end. The plate dimensions are yp = 0, xp = 0.9*x, zp=0.9*z (all constants) excited by the Ex component. The resulting Hz component is displayed.

I can use all the help I can get.
http://www.rfcafe.com/references/electrical/waveguide.htm

Start here aero. The waveguide dims that should be used are the WR 340 or the WR430 as they are OTS waveguides falling into the 2.45 GHz range.



If you want Ill send you my pdfs of my waveguide to coax I should be getting today,

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 12:18 AM
Here is the  waveguide>coax that's in the mail. Maybe tomorrow.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 12:19 AM
some more parts
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 12:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424747#msg1424747">Quote from: SeeShells on 09/10/2015 10:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424700#msg1424700">Quote from: aero on 09/10/2015 07:46 PM</a>
I don't know what I'm doing but here is my "Magnetron/waveguide" feed.

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

I've coded a constant frequency for use as a wave length ruler, and am exciting the cavity at a variable frequency parameter, both are set to 2.47 GHz, and the constant won't change.

The dimensions are x= wl/4, z = wl/2 and the length, y = 2*wl. (constants) The x and z dimensions are then increased by 30% as I read somewhere that they should be. I hope to be able to shorten the y dimension as that length will make the meep computational lattice quite large.

The structure is excited from a rectangular plate wl/4 from the big end. The plate dimensions are yp = 0, xp = 0.9*x, zp=0.9*z (all constants) excited by the Ex component. The resulting Hz component is displayed.

I can use all the help I can get.
http://www.rfcafe.com/references/electrical/waveguide.htm

Start here aero. The waveguide dims that should be used are the WR 340 or the WR430 as they are OTS waveguides falling into the 2.45 GHz range.



If you want Ill send you my pdfs of my waveguide to coax I should be getting today,

http://www.wikarekare.org/Antenna/Waveguide.html

This should give you the simplest design to model aero.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/11/2015 01:39 AM
Ok Shell, while you were doing that I went ahead and replaced my dimensions with the WR 340 dimensions, and replaced the exciter plate with a short stub in the x dimension (width - smallest dimension). That is, a stub 0.04318/2 = 0.02159 meters long. Views are here:

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

Is this what you have in mind, and may I ask a question?

"Do you want the meep model to reflect the hardware exactly as you plan to build it, or do you want it to reflect an idealization of what could perhaps be built along the lines of your plans?"
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/11/2015 02:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424780#msg1424780">Quote from: SeeShells on 09/11/2015 12:18 AM</a>
Here is the  waveguide>coax that's in the mail. Maybe tomorrow.

Hey Shell,

What company did you order this waveguide to coax from?
We have recieved quotes for N type adapters that run $800+ and are looking for cheaper alternatives.

Thanks,

Kurt

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 02:27 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424843#msg1424843">Quote from: zellerium on 09/11/2015 02:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424780#msg1424780">Quote from: SeeShells on 09/11/2015 12:18 AM</a>
Here is the  waveguide>coax that's in the mail. Maybe tomorrow.

Hey Shell,

What company did you order this waveguide to coax from?
We have recieved quotes for N type adapters that run $800+ and are looking for cheaper alternatives.

Thanks,

Kurt
Kurt,
This guy on ebay gave me great support and the prices were great. The entire package cost me around $200 but still needed to get N Connectors and coax. I'll do my own antennas.

Contact him directly by his email of browse his ebay link. I'll send you his email in a PM.

http://www.ebay.ca/itm/121494649101?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 02:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424804#msg1424804">Quote from: aero on 09/11/2015 01:39 AM</a>
Ok Shell, while you were doing that I went ahead and replaced my dimensions with the WR 340 dimensions, and replaced the exciter plate with a short stub in the x dimension (width - smallest dimension). That is, a stub 0.04318/2 = 0.02159 meters long. Views are here:

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

Is this what you have in mind, and may I ask a question?

"Do you want the meep model to reflect the hardware exactly as you plan to build it, or do you want it to reflect an idealization of what could perhaps be built along the lines of your plans?"
I think for the way we have worked together we should start off with the very basic designs and wring out the issues and evolve it from there. More work but less problems with miss-communications.

I think you have a great start aero with a very basic model and see if you can get the frustum cavity to resonate and do a few snapshots.

You know I want to end up with dual injectors 180 degree opposing that can wait, let's take small steps.

Shell

PS: the waveguide looks nice aero!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/11/2015 03:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423469#msg1423469">Quote from: Mulletron on 09/07/2015 01:35 AM</a>
A very impressive lecture on RF cavities. Gets good around slide 40.

http://uspas.fnal.gov/materials/10MIT/Lecture6.pdf

and all the other ones:
https://www.google.it/search?q=resonant+cavities+site:uspas.fnal.gov&ie=utf-8&oe=utf-8&gws_rd=cr&ei=GevsVcT_K8a3a_yjv6AE

I wanted to point out a problem in the MIT presentation (bold and underlined) lecture 6 on page 55 as it could cause some one frustration if trying to calculate the frequency for a cylindrical cavity.  Their units for the frequency equation are not correct are correct.  They may have included an extra speed of light constant edit: it may appear.  I believe all they need is the 1/sqrt(mu*epsilon) and not c/sqrt(mu_r*epsilon_r) Edit: is used but mu_r and epsilon_r are ratios.  After this i get the right units and about the right dimensions for "a" and "d".  I found it helpful and thanks. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: EquiFritz on 09/11/2015 03:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424422#msg1424422">Quote from: dustinthewind on 09/09/2015 11:41 PM</a>
Suggestions, that I should move it to a new thread?

I mean no disrespect, but I would suggest moving your questions into a new thread. While the term "EM Drive" could be applied to numerous theoretical devices; I think it's fair to say that in the context of this thread, "EM Drive" is specifically referring to the design and theories presented by Shawyer. As a non-scientist viewing these discussions with a limited knowledge of physics, it's already difficult enough to keep up with the conversation here when it's focused on the frustum devices. Inserting "any device which could be described as an EM Drive" into this thread just muddies the waters even further. Again, I apologize to all of the regular posters to this thread if I'm speaking out of line, but I felt it necessary to make this suggestion.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/11/2015 05:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424899#msg1424899">Quote from: EquiFritz on 09/11/2015 03:55 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424422#msg1424422">Quote from: dustinthewind on 09/09/2015 11:41 PM</a>
Suggestions, that I should move it to a new thread?

I mean no disrespect, but I would suggest moving your questions into a new thread. While the term "EM Drive" could be applied to numerous theoretical devices; I think it's fair to say that in the context of this thread, "EM Drive" is specifically referring to the design and theories presented by Shawyer. As a non-scientist viewing these discussions with a limited knowledge of physics, it's already difficult enough to keep up with the conversation here when it's focused on the frustum devices. Inserting "any device which could be described as an EM Drive" into this thread just muddies the waters even further. Again, I apologize to all of the regular posters to this thread if I'm speaking out of line, but I felt it necessary to make this suggestion.

Initially I did start a separate thread.  There was a suggestion to merge, if I remember correctly, and I ended up letting my old thread go.  I still have questions as to what is really behind the EM drive, if it works, but it looks like there is a lot of experimental work now and I don't want to create confusion between the two.  I'll have to consider migrating back to the old thread or starting a new one.  There is still the possibility it is all related so I'll still be watching. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/11/2015 01:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424895#msg1424895">Quote from: dustinthewind on 09/11/2015 03:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423469#msg1423469">Quote from: Mulletron on 09/07/2015 01:35 AM</a>
A very impressive lecture on RF cavities. Gets good around slide 40.

http://uspas.fnal.gov/materials/10MIT/Lecture6.pdf

and all the other ones:
https://www.google.it/search?q=resonant+cavities+site:uspas.fnal.gov&ie=utf-8&oe=utf-8&gws_rd=cr&ei=GevsVcT_K8a3a_yjv6AE

I wanted to point out a problem in the MIT presentation (bold and underlined) lecture 6 on page 55 as it could cause some one frustration if trying to calculate the frequency for a cylindrical cavity.  Their units for the frequency equation are not correct.  They may have included an extra speed of light constant.  I believe all they need is the 1/sqrt(mu*epsilon) and not c/sqrt(mu*epsilon).  After this i get the right units and about the right dimensions for "a" and "d"... I think.  Other than that, I found it helpful and thanks.

There is nothing wrong with the "the MIT presentation (bold and underlined) lecture 6 on page 55" for the frequency for a cylindrical cavity,

Their units for the frequency equation are correct.

The equations on page 55 of the MIT presentation are correct.

It appears that you are either not noticing that the MIT equations have the relative permittivity and relative permeability or that you are confusing the relative values to the absolute values.

Relative permeability, sometimes denoted by the symbol μr, is the ratio of the permeability of a specific medium to the permeability of free space, μ0.  Ditto for the permitivity.

Both the relative permeability and the relative permittivity are dimensionless.

"c" is the speed of light, it has dimensions of length/time.
The expression from the Square Root has dimensions of 1/length, since trivially, the Square Root of the Square of 1 over the radius, or the Square of 1 over the length, has dimensions of 1 over length.

Pi, p in the Wikipedia article, or equivalently q in the MIT presentation, Xmn and X'mn are all dimensionless.

Therefore frequency has dimensions of 1/time which is correct.


The equation in the MIT presentations is the same equation as in https://en.wikipedia.org/wiki/Microwave_cavity#Cylindrical_cavity

(2e6d0f20301f3df351e6e0e5c02b47aa.png)

(04bb57cef06a099673230ccf53d904fb.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 01:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424843#msg1424843">Quote from: zellerium on 09/11/2015 02:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424780#msg1424780">Quote from: SeeShells on 09/11/2015 12:18 AM</a>
Here is the  waveguide>coax that's in the mail. Maybe tomorrow.

Hey Shell,

What company did you order this waveguide to coax from?
We have recieved quotes for N type adapters that run $800+ and are looking for cheaper alternatives.

Thanks,

Kurt

Cheap it out? Well a very low cost way to do dual waveguide injectors into the sidewalls 180 out of phase or just one would be like this...

Another way would be to mount the magnetron onto a waveguide> WR340 or 430 to antenna, then use a splitter for the Cavity Directional Coupler 800-2500MHz N 10db wide band signal 1.2/2.4/3G/4GHz from Ebay running to dual coax>waveguides 180 degrees opposing into the frustum.

You would need to make one of the coax's a Lambda/2 wavelength to provide the required 180 deg phase shift on one of the ports. VNA the cavity to fine tune the coaxial lengths and fine tune the phases. You could also drill and tap a couple holes and use trim screws in each waveguide on the frustum for finer tuning.

This setup WO the maggie and power supply would run $700-800  including coax. and adaptors.

Use a inverter power supply for the magnetron and good magnetron under $120.

I think this is something aero could model here quite quickly with your frustum dimensions just using the waveguide he created and making sure he could do the waveguides 180 degrees apart on the sidewalls of the frustum and 180 degree phase shifted.

Morning coffee thoughts...

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/11/2015 02:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424884#msg1424884">Quote from: SeeShells on 09/11/2015 02:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424804#msg1424804">Quote from: aero on 09/11/2015 01:39 AM</a>
Ok Shell, while you were doing that I went ahead and replaced my dimensions with the WR 340 dimensions, and replaced the exciter plate with a short stub in the x dimension (width - smallest dimension). That is, a stub 0.04318/2 = 0.02159 meters long. Views are here:

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

Is this what you have in mind, and may I ask a question?

"Do you want the meep model to reflect the hardware exactly as you plan to build it, or do you want it to reflect an idealization of what could perhaps be built along the lines of your plans?"
I think for the way we have worked together we should start off with the very basic designs and wring out the issues and evolve it from there. More work but less problems with miss-communications.

I think you have a great start aero with a very basic model and see if you can get the frustum cavity to resonate and do a few snapshots.

You know I want to end up with dual injectors 180 degree opposing that can wait, let's take small steps.

Shell

PS: the waveguide looks nice aero!

Shell - I am sure you are aware off all this but for anyone using coax feeds:

A couple of cautions about using coax. 

1) similar to real estate, with coax it is Low Loss, Low Loss, Low Loss - The Traveller had ID some good low loss coax back on Thread 3 (I think - can't find it with the wonderful search function).  Expensive but very good.

2) Length is important, particularly if you are going for a dual feed.  with a wavelength OTO of 12 cm, each 6cm  is about a half wavelength and thus your impedance radically changes.   Make sure to work your lengths out on smith chart or similar approach.

3) Loss (see item 1) for coax is normally referenced to a low SWR configuration (high RL).  All well and good BUT with our noisy wide bandwidth maggies that is harder to achieve.   Make sure to look at loss in off design configurations. 

All I am saying here is that design of the coax feed system must be done carefully with these freqs and types of wideband sources. 

Having said that - coax is generally much easier to work with than plumbing up waveguides.   That is one of the driving forces behind the development of low loss Ghz coax.   And good design is very do-able.  There are quite a few references on the web - from very basic to quite theoretical.   One of my favorites is  "Reflections III Transmission Lines & Antennas"  by Walter Maxwell.   (W2DU - SK).  Very readable and also includes quite a bit of data on smith charts.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/11/2015 02:10 PM
Aero, meepers -

I've finished up my efforts on generating Scheme code to model a mesh. The attached Excel files model NSF1701 dimensions from the wiki repository. There are two files:

MeshGenNSF1701 models a 'colander' with variable sized holes, proportional to the frustrum radius.
MeshGenNSF1701_rolled models a fixed sized mesh 'rolled' into a cone, including a seam with no holes.

Both files use the same hole size and spacing. Both contain charts showing the x-y and x-z positions of the holes, which are enough to convince me the sheets are approximately correct. I can fix any problems people spot if anyone decides to actually use them with MEEP. Second file is moderately slow to run.

I guess there may well be costs to using such a complex description, possibly in additional loading or processing time. If there are no such costs, it would seem sensible to simulate what we actually have if we can, but that is up to those running MEEP.

I accept that long-wavelength wave reflection may not be perturbed much by a fine mesh, so much of the function of a mesh cavity will be similar to a solid cavity. However, I do find it hard to believe that the conductivity of a sheet of copper full of holes is exactly the same as a sheet of copper without. Given that Q at resonance is strongly related to dissipation and therefore resistance, I would expect that Q would depend on the mesh structure.

That said, far and away the most convincing thing would be to measure Q in these replications, rather than depend on theory or simulation.

Cheers,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/11/2015 02:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425010#msg1425010">Quote from: RERT on 09/11/2015 02:10 PM</a>
...
I accept that long-wavelength wave reflection may not be perturbed much by a fine mesh, so much of the function of a mesh cavity will be similar to a solid cavity. However, I do find it hard to believe that the conductivity of a sheet of copper full of holes is exactly the same as a sheet of copper without....

The conductivity of a sheet of copper full of holes has to do with the percolation threshold.  Even though there are many holes, there are a huge number of continuous paths to establish conductivity, hence the percolation threshold for conductivity is fully met and well exceeded:

A. L. Efros and B. I. Shklovskii, Critical Behaviour of Conductivity and Dielectric Constant near the Metal-Non-Metal Transition Threshold, Phys. Status Solidi B 76, 475 (1976)
J. P. Clerc, G. Giraud, J. M. Laugier and J. M. Luck, The electrical conductivity of binary disordered systems, percolation clusters, fractals and related models, Adv. Phys. 39, 191 (1990)
D. J. Bergman and D. Stroud, Physical Properties of Macroscopically Inhomogeneous Media, hg. von H. Ehrenreich und D. Turnbull, Bd. 46, Solid State Physics (Academic Press inc., 1992)



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/11/2015 02:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424737#msg1424737">Quote from: Ricvil on 09/10/2015 09:46 PM</a>
310px-TransmissionLineDefinitions.svg.png
Gaussian_Pulse_in_Transmission_Line.png
00133x01.png

See these three figures.
They shows basicaly, how a pulse travels along a transmission line.
Note the current flow on each wire of transmission line. Same amplitude, opposite signal.
Then imagine the loop antenna at the end of transmission line.
What would be the form of the currents reaching the loop antenna?
Why we are seeing only one current flux reaching the loop antenna by just one side?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424706#msg1424706">Quote from: X_RaY on 09/10/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424694#msg1424694">Quote from: Ricvil on 09/10/2015 07:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?
At low frequencies it is not important at all. But if the loop is in the dimension of the wavelength the situation is clear different. For example, if you look to smith diagram, between 0.5 and ~0.95 wavelengths the loop acts capacitive.

A standing wave at the antenna loop is only true if the antenna itself is also in resonance (exact multiple of half wavelength).
And yes in real world one have reflections at every discontinuity...

If this is not a answer to your question, please formulate a clear question. English isn't my natural language..

http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/loop.html (@Shell, thanks for this link :) )
http://www.antennenkoppler.de/achim/antenna/Impedanz_im_Smith_1.html
Yes true, the first flow around the circumference looks a little bit art.
I think it's the result of the current implementation in MEEP. aero explained what he did here
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422975#msg1422975
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 02:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425000#msg1425000">Quote from: Rodal on 09/11/2015 01:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424895#msg1424895">Quote from: dustinthewind on 09/11/2015 03:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423469#msg1423469">Quote from: Mulletron on 09/07/2015 01:35 AM</a>
A very impressive lecture on RF cavities. Gets good around slide 40.

http://uspas.fnal.gov/materials/10MIT/Lecture6.pdf

and all the other ones:
https://www.google.it/search?q=resonant+cavities+site:uspas.fnal.gov&ie=utf-8&oe=utf-8&gws_rd=cr&ei=GevsVcT_K8a3a_yjv6AE

I wanted to point out a problem in the MIT presentation (bold and underlined)

There is nothing wrong with the "the MIT presentation (bold and underlined) lecture 6 on page 55" for the frequency for a cylindrical cavity,


I liked this as it was a good place for a nice grouping of formulas.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/11/2015 03:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425007#msg1425007">Quote from: graybeardsyseng on 09/11/2015 02:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424884#msg1424884">Quote from: SeeShells on 09/11/2015 02:37 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424804#msg1424804">Quote from: aero on 09/11/2015 01:39 AM</a>
Ok Shell, while you were doing that I went ahead and replaced my dimensions with the WR 340 dimensions, and replaced the exciter plate with a short stub in the x dimension (width - smallest dimension). That is, a stub 0.04318/2 = 0.02159 meters long. Views are here:

https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tUWZVY2RMc3lJbVU&usp=sharing)

Is this what you have in mind, and may I ask a question?

"Do you want the meep model to reflect the hardware exactly as you plan to build it, or do you want it to reflect an idealization of what could perhaps be built along the lines of your plans?"
I think for the way we have worked together we should start off with the very basic designs and wring out the issues and evolve it from there. More work but less problems with miss-communications.

I think you have a great start aero with a very basic model and see if you can get the frustum cavity to resonate and do a few snapshots.

You know I want to end up with dual injectors 180 degree opposing that can wait, let's take small steps.

Shell

PS: the waveguide looks nice aero!

Shell - I am sure you are aware off all this but for anyone using coax feeds:

A couple of cautions about using coax. 

1) similar to real estate, with coax it is Low Loss, Low Loss, Low Loss - The Traveller had ID some good low loss coax back on Thread 3 (I think - can't find it with the wonderful search function).  Expensive but very good.

2) Length is important, particularly if you are going for a dual feed.  with a wavelength OTO of 12 cm, each 6cm  is about a half wavelength and thus your impedance radically changes.   Make sure to work your lengths out on smith chart or similar approach.

3) Loss (see item 1) for coax is normally referenced to a low SWR configuration (high RL).  All well and good BUT with our noisy wide bandwidth maggies that is harder to achieve.   Make sure to look at loss in off design configurations. 

All I am saying here is that design of the coax feed system must be done carefully with these freqs and types of wideband sources. 

Having said that - coax is generally much easier to work with than plumbing up waveguides.   That is one of the driving forces behind the development of low loss Ghz coax.   And good design is very do-able.  There are quite a few references on the web - from very basic to quite theoretical.   One of my favorites is  "Reflections III Transmission Lines & Antennas"  by Walter Maxwell.   (W2DU - SK).  Very readable and also includes quite a bit of data on smith charts.

Herman
Great points Herman! This was for our collage friends here with a restricted budget. Thanks for the reference!

You are correct, it's doable but, if you're considering the costs of a waveguide vs coaxial runs into your build it is a good option. And you need to know the points you just brought up.

I ended up with http://www.vibroplex.com/techdocs/ssb/Ecoflex15Plus.pdf which is quite low loss and will handle the 3-400 watts at these frequencies.

I also recommended that they look at a inverter power supply whose duty cycle isn't 30x a second and will give a cleaner 2.47GHz output. You can get 1200 watts out of a good coupling of maggie and inverter power supply and there are some good tricks you can do on the inverter to filter for an even better output.

Also they will be needing to get the little files out to fine tune the cable lengths and reassembling then testing and reassembling and retesting and and again (ask me how I know?).

Can I do a Spock "mind meld" with you?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/11/2015 04:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425002#msg1425002">Quote from: SeeShells on 09/11/2015 01:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424843#msg1424843">Quote from: zellerium on 09/11/2015 02:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424780#msg1424780">Quote from: SeeShells on 09/11/2015 12:18 AM</a>
Here is the  waveguide>coax that's in the mail. Maybe tomorrow.

Hey Shell,

What company did you order this waveguide to coax from?
We have recieved quotes for N type adapters that run $800+ and are looking for cheaper alternatives.

Thanks,

Kurt

Cheap it out? Well a very low cost way to do dual waveguide injectors into the sidewalls 180 out of phase or just one would be like this...

Another way would be to mount the magnetron onto a waveguide> WR340 or 430 to antenna, then use a splitter for the Cavity Directional Coupler 800-2500MHz N 10db wide band signal 1.2/2.4/3G/4GHz from Ebay running to dual coax>waveguides 180 degrees opposing into the frustum.

You would need to make one of the coax's a Lambda/2 wavelength to provide the required 180 deg phase shift on one of the ports. VNA the cavity to fine tune the coaxial lengths and fine tune the phases. You could also drill and tap a couple holes and use trim screws in each waveguide on the frustum for finer tuning.

This setup WO the maggie and power supply would run $700-800  including coax. and adaptors.

Use a inverter power supply for the magnetron and good magnetron under $120.

I think this is something aero could model here quite quickly with your frustum dimensions just using the waveguide he created and making sure he could do the waveguides 180 degrees apart on the sidewalls of the frustum and 180 degree phase shifted.

Morning coffee thoughts...

Shell

Aren't tuning screws ill-advised at high power because of arcing?
Also, how would you mitigate the reflected power back to the magnetron?

We're not trying to 'cheap it out' we're trying to stay within our budget. 
Right now it seems the best option is a 200 W solid state amplifier that we could purchase for ~ 3,000. Then we buy an isolator, coax to waveguide, and create our frustum with aperture coupling.

I think symmetric power delivery may be more valuable in higher power situations and we could be better off sticking with the simpler method so we don't end up over our heads trying to make sure our two waveguides are 180 degrees out of phase. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Ricvil on 09/11/2015 04:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425018#msg1425018">Quote from: X_RaY on 09/11/2015 02:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424737#msg1424737">Quote from: Ricvil on 09/10/2015 09:46 PM</a>
310px-TransmissionLineDefinitions.svg.png
Gaussian_Pulse_in_Transmission_Line.png
00133x01.png

See these three figures.
They shows basicaly, how a pulse travels along a transmission line.
Note the current flow on each wire of transmission line. Same amplitude, opposite signal.
Then imagine the loop antenna at the end of transmission line.
What would be the form of the currents reaching the loop antenna?
Why we are seeing only one current flux reaching the loop antenna by just one side?

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424706#msg1424706">Quote from: X_RaY on 09/10/2015 08:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424694#msg1424694">Quote from: Ricvil on 09/10/2015 07:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423412#msg1423412">Quote from: X_RaY on 09/06/2015 07:07 PM</a>


Why the field on the loop antena appears like a traveling wave along the loop? The current is not balanced?
When a loop is feeded by a transmission line there are two antisymmetric current waves, and one will see the fields on the loop arising as two couterpropagating waves and resulting a stationary wave on the loop.
What is going on?
At low frequencies it is not important at all. But if the loop is in the dimension of the wavelength the situation is clear different. For example, if you look to smith diagram, between 0.5 and ~0.95 wavelengths the loop acts capacitive.

A standing wave at the antenna loop is only true if the antenna itself is also in resonance (exact multiple of half wavelength).
And yes in real world one have reflections at every discontinuity...

If this is not a answer to your question, please formulate a clear question. English isn't my natural language..

http://personal.ee.surrey.ac.uk/Personal/D.Jefferies/loop.html (@Shell, thanks for this link :) )
http://www.antennenkoppler.de/achim/antenna/Impedanz_im_Smith_1.html
Yes true, the first flow around the circumference looks a little bit art.
I think it's the result of the current implementation in MEEP. aero explained what he did here
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422975#msg1422975
http://forum.nasaspaceflight.com/index.php?topic=38203.msg1422926#msg1422926

If I understood what was done, the loop antenna model is in fact a loop of pontual source fields turned on in sequence.
Unfortunely I think this will not model many physical aspects of a real loop antenna.
This explain the rotation behavior of the fields inside cavity.
A more realistic model perhaps would be a ring of conducting material, with a pontual electric field inside a arbitrary location on the ring, and pointing along the circunference of the ring.
The electric field inside the conductor material of the ring will produce the current flux J=sigma.E, and the current waves will flow along the ring.
If it works, then the influence of the antenna  impedance will appear in the resulting fields inside cavity.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/11/2015 04:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425061#msg1425061">Quote from: zellerium on 09/11/2015 04:25 PM</a>
Aren't tuning screws ill-advised at high power because of arcing?
Also, how would you mitigate the reflected power back to the magnetron?

We're not trying to 'cheap it out' we're trying to stay within our budget. 
Right now it seems the best option is a 200 W solid state amplifier that we could purchase for ~ 3,000. Then we buy an isolator, coax to waveguide, and create our frustum with aperture coupling.

I think symmetric power delivery may be more valuable in higher power situations and we could be better off sticking with the simpler method so we don't end up over our heads trying to make sure our two waveguides are 180 degrees out of phase.

Since I have a lot of reading time at present, here are 2 breadcrumbs from Shawyer's most recent patent document, attached.

1) Note the use of a narrow SLIT that is located at the middle of the frustum side wall length and on the frustum side wall. Imaging the wavefronts emerging on the frustum side of that slit.

2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

My current thoughts are to follow the narrow slit, in the middle of the side wall length, on the frustum side wall Shawyer example, with a Coax to waveguide adapter / impedance matcher as Prof Yang devised and to avoid entirely the use of an internal to the frustum antenna.

Additionally to experiment with short RF excitation pulses, being a fraction of 1 frustum TC.

Nice to read doing the polish out improved your cavity Q. See Shawyer does drop useful breadcrumbs.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/11/2015 05:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425000#msg1425000">Quote from: Rodal on 09/11/2015 01:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424895#msg1424895">Quote from: dustinthewind on 09/11/2015 03:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1423469#msg1423469">Quote from: Mulletron on 09/07/2015 01:35 AM</a>




There is nothing wrong with the "the MIT presentation (bold and underlined) lecture 6 on page 55" for the frequency for a cylindrical cavity,

...

It appears that you are either not noticing that the MIT equations have the relative permittivity and relative permeability or that you are confusing the relative values to the absolute values.
...

Thanks Rodal, that helps and you are correct.  I was not thinking of them as relative permittivity, r_permeability or ratios.  It makes more sense to me now. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 09/11/2015 07:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425084#msg1425084">Quote from: TheTraveller on 09/11/2015 04:55 PM</a>
2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

Great to see you back!!  :D

This is a very interesting insight into how Shawyer may now see this phenomena working.  It is almost like striking a bell!  Very, very interesting.  Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer.  Hm.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/11/2015 08:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424713#msg1424713">Quote from: Mulletron on 09/10/2015 08:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1424636#msg1424636">Quote from: SteveD on 09/10/2015 04:54 PM</a>
Has anyone done a mathematical proof to make sure a stable TE012 is possible in a frustum at these frequencies?  We would all feel a bit silly if we spent all this time and effort trying to do something that was impossible.  (Certain ironies with the above statement and this entire project are noted).

Speaking of which, here is the dispersion measure plot from the Arecibo, Fast Radio Burst detection.  I've said elsewhere that I think its either the result of the classified project Shawyer says he was working on (very likely) or possibly somebody else using an EMDrive subject to engineering restraints we are not currently aware of (highly unlikely going to extremely unlikely if that somebody is not associated with the planet Earth).  Since I don't know the cutoff for Arecibo's equipment this is of limited value (if a full run starts at 1hz and goes all the way up to the high gammas it clearly stellar in nature).  Still, I can't help but feel that if I could, arbitrarily, pick a frequency to start poking about around with an EMDrive, somewhere in this range might bear interesting fruit.  (Paper: http://arxiv.org/abs/1404.2934 (http://arxiv.org/abs/1404.2934))

Hi, I think I saw you talking about the FRB thing on Reddit. I honestly don't understand what you are saying. Can you ELI5 it to us please?

https://www.reddit.com/r/EmDrive/comments/3jwpdi/cribbing_somebody_elses_notes/

We're working on this as a space drive.  We think it might go faster if you put more power into it.  If you want to travel stellar distances with a large amount of mass, you might put a lot of power into it.  The more power you poor in the more heat you're going to get.  If you pour enough power into it, the heat will start melting things.  The end of the frustum opposite the RF source is high on my list of things that might melt.

If the end of the frustum melts, the thing will no longer be in resonance.  TheTraveller has suggested using a computer to run through frequencies in 1khz (or was it 100khz) increments looking for resonance.  A computer on a probe or ship that has just melted the end of its frustum might default to searching for resonance when the frustum starts melting. 

The distance from FRBs is estimated based on the dispersion measure of the signal.  Basically, it assumes that there is one burst on multiple frequencies and that the arrival time is spread out by the interstellar medium.  A computer tuning an EMDrive would spread out the arrival time of waves, not because of the interstellar medium but because its going through difference frequencies sequentially over time.  In effect, it creates a fake dispersion measure.  All the known FRBs have dispersion measures that are multiples of 187.5.  This would tend to indicate that 187.5 is either the result of an engineering decision or some as yet unknown physical process.

FRBs tend to have a strength of around 1 Jansky.   That's 10^-26 Watts per m^2 of the reflecting surface on the radio telescope.   If I did the math right (might not have) a points source approximately 10 light years distant would need a power of 89 megawatts for a 1 jy detection growing to 800 megawatts at 30 ly.  That's before taking in a bunch of complexity such as waveguides, non-point sources and the question of just what type of antenna you pump a gigawatt through and not vaporize.  Alternatively, you could have a much weaker source much closer to home.  An rf source on the range of 100mw to 1gw is nuts, but it's nuts in the same way building the great pyramids is nuts.  If the EM Drive actually worked, I could see an effort to produce something that could put out such crazy levels of power.

The dish at Arecibo is huge.  Microwaves (though normally on the radar part of the spectrum) can be used to image objects, you just need a very large dish to be able to resolve them.  I'm looking at the output from Arecibo and wondering if one gigawatt of rf energy might be enough to pick out the shadow created by antennas within the frustum.  This has a number of variables that I just don't know.  I think the answer is no but am not sure of it.

So basically, I'm looking at an image from Arecibo that could be interpreted as some type of EMDrive, with multiple antenna that has vaporized its base plate that is now expanding away from the drive causing that glowing outline at the sides of the image. 

That's the somewhat happy, or maybe naive, interpretation.  Shawyer say's he discovered the EMDrive effect while working on a classified project relating to guidance of nuclear weapons.  Such a guidance system might involve use of satellites in orbit.  To avoid jamming such a satellite might attempt to belt out a beacon on multiple frequencies.  Circular polarization of the signal might help avoid spoofing.  A test of this guidance system would also look like a FRB (and an EMDrive).  So what I think I'm really seeing is a radar image showing parts of a satellite in Earth orbit. 

It sure does look like an advance frustum though.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dustinthewind on 09/11/2015 08:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425183#msg1425183">Quote from: SteveD on 09/11/2015 08:07 PM</a>
...Shawyer say's he discovered the EMDrive effect while working on a classified project relating to guidance of nuclear weapons.  Such a guidance system might involve use of satellites in orbit.  ...


Interesting, though I guess I had assumed that maybe they were dealing with a force on satellites in orbit that were transmitting radiation towards earth with a feed horn.  A feed horn being similar to a frustum, I was thinking.  My guess was that there was more force than appeared to be due to radiation transmission.  Maybe I was wrong in my speculation of course.  It was one of the reasons I was interested in Tod's getting a larger than radiation force possibly from an open ended frustum with the transmitter located near the peak, if I was following that correctly. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/11/2015 09:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425186#msg1425186">Quote from: sghill on 09/11/2015 08:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425151#msg1425151">Quote from: demofsky on 09/11/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425084#msg1425084">Quote from: TheTraveller on 09/11/2015 04:55 PM</a>
2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

Great to see you back!!  :D

This is a very interesting insight into how Shawyer may now see this phenomena working.  It is almost like striking a bell!  Very, very interesting.  Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer.  Hm.

Would that explain the long duration drop off after the power is turned off?

No.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/11/2015 11:42 PM
NSF-1701 update. Controller/display arrived for lds. Hope to run calibration test this weekend. No DAQ interface yet, so will let the video do it for now. Next week, hope to have a 10 bit adc ordered then choose some laptop software to record the time and displacement data. 3 msec data rate should be fine. Trying to avoid too many electronic data channels, not convinced of their reliability in high em fields yet...time will tell.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: WarpTech on 09/12/2015 01:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425151#msg1425151">Quote from: demofsky on 09/11/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425084#msg1425084">Quote from: TheTraveller on 09/11/2015 04:55 PM</a>
2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

Great to see you back!!  :D

This is a very interesting insight into how Shawyer may now see this phenomena working.  It is almost like striking a bell!  Very, very interesting.  Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer.  Hm.

I've said it a few times, that a high power system only requires a spark-gap switch. It doesn't need to be pulsed at 2.45GHz, Given the long time constant of a high Q resonator, I suspect the frequency of the impulse only needs to be in the Hz or kHz range to resonate, but the impulse needs to be very narrow. Which means a wide gap and high voltage capacitors.
Todd

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/12/2015 02:27 AM
Hum, I think I've found a way to somewhat definitively kill my little green men hypothesis.  Since having dispersion measures that are multiples of 187.5 means the dispersion measures suggesting FRBs are extra-galactic are almost certainly wrong, it may be safe to assume a relation between FRBs (in fact my classified sat hypothesis is based on all of them being a handful of objects in Earth orbit).

FRB 110703 was detected at 23h30' RA; -02d52' dec
FRB 120127 was detected at 23h15' RA; -18d25' dec

FRB 110220 was detected at 22h34' RA; -12d24' dec
FRB 140514 was detected at 22h34' RA; -12d18' dec (all J2000)

It strikes me that if these 4 FRBs represent two objects with a common point of origin it would be possible to draw a line intersecting at that point (or possibly one satellite who's orbit is being varied by its controlling government).

Working from the power requirements for a 1 Jy detection, an rf point source would require about a gigawatt of power behind it to be picked up at 30 ly.  I can therefor assume that, given any plausible margin of error, that common point of origin must be within 100 ly for little green men.

So run the two lines and get a right ascension and declination of where they cross.  Then go check a stellar catalog to see if their are any stars around that point at 100 ly distance or less.  If you get a hit on a F,G or K main sequence star, you've got a SETI candidate.  If you don't then I've done part of the work of helping an intrepid grad student with a paper arguing that FRBs are the result of emissions from terrestrial satellites.

So um, here's the thing.  I don't feel particularly competent doing the math to arrive at a proposed common point of origin.  Can somebody help me out by figuring where in the sky those two lines should meet?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/12/2015 03:57 AM
http://phys.org/news/2015-09-spacex-peek-crew-vehicle.html
This is one beautiful looking space vehicle.
Sorry just had to post. Spent the day getting the lasers lined up and still having issues with the red one, think I got a bad laser as I can't get it to define a nice spot even with a pinhole lens and I tried several different ones. I guess I'll need to order another, they are not the costly.

Got the scales stable attached to a set of micrometer gauges secured under the scale table (old ones I took apart) to use the screw mechanism to fine tune and set the digital scales height.

Got the Faraday cage door finished and checked out, it's radiation proof. ;)

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 09/12/2015 05:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425208#msg1425208">Quote from: Rodal on 09/11/2015 09:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425186#msg1425186">Quote from: sghill on 09/11/2015 08:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425151#msg1425151">Quote from: demofsky on 09/11/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425084#msg1425084">Quote from: TheTraveller on 09/11/2015 04:55 PM</a>
2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

Great to see you back!!  :D

This is a very interesting insight into how Shawyer may now see this phenomena working.  It is almost like striking a bell!  Very, very interesting.  Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer.  Hm.

Would that explain the long duration drop off after the power is turned off?

No.

Have to agree with Rodal.  From a microwave perspective you are looking probably at nanoseconds (femtoseconds?) unless I am missing something.  Same thing would be true as far as I know for any ionized gasses rattling around.  Couldn't speak to how long a superconducting EM bell would ring on its own but it would likely still be much shorter than say a millisecond, if that.

The insight for me is that the EM Drive could possibly be best driven by a pulsed power source and not a continuous one.

That said, that long duration drop off is one of those signals that makes this such a tar patch.  It shows up in different experiments, usually explained away as either thermals or stiction in the measuring apparatus. 

Thing is, while thrust does not require new physics, this duration thing would if it is not just an experimental artifact...


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/12/2015 06:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425380#msg1425380">Quote from: SeeShells on 09/12/2015 03:57 AM</a>
http://phys.org/news/2015-09-spacex-peek-crew-vehicle.html
This is one beautiful looking space vehicle.
Sorry just had to post. Spent the day getting the lasers lined up and still having issues with the red one, think I got a bad laser as I can't get it to define a nice spot even with a pinhole lens and I tried several different ones. I guess I'll need to order another, they are not the costly.

Got the scales stable attached to a set of micrometer gauges secured under the scale table (old ones I took apart) to use the screw mechanism to fine tune and set the digital scales height.

Got the Faraday cage door finished and checked out, it's radiation proof. ;)

Shell

It's probably just stray photon molecules:

https://www.extremetech.com/extreme/213974-breakthrough-nist-study-creates-molecules-out-of-photons

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/12/2015 11:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425402#msg1425402">Quote from: Stormbringer on 09/12/2015 06:57 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425380#msg1425380">Quote from: SeeShells on 09/12/2015 03:57 AM</a>
http://phys.org/news/2015-09-spacex-peek-crew-vehicle.html
This is one beautiful looking space vehicle.
Sorry just had to post. Spent the day getting the lasers lined up and still having issues with the red one, think I got a bad laser as I can't get it to define a nice spot even with a pinhole lens and I tried several different ones. I guess I'll need to order another, they are not the costly.

Got the scales stable attached to a set of micrometer gauges secured under the scale table (old ones I took apart) to use the screw mechanism to fine tune and set the digital scales height.

Got the Faraday cage door finished and checked out, it's radiation proof. ;)

Shell

It's probably just stray photon molecules:

https://www.extremetech.com/extreme/213974-breakthrough-nist-study-creates-molecules-out-of-photons
Homer Simpson..."mmmmmm  Pretty Blue Balls"
Interesting that they stuck two photons together and made them stick, what is it? Like a quantum entanglement but attached at the hip. So does that mean they are Gluoned together?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/12/2015 02:46 PM
Dr. Rodal -

Here's a thought experiment: consider a rectangular slab of copper, with one circular hole in the middle.

I submit that it is obvious that the resistance from one side of the plate to the other becomes very large as the diameter of the hole approaches the width of the slab. The same will be true for any collection of smaller holes which almost 'cut' across the plate, leaving only a number of thin connections between one side and the other.

That the 'hole structure' of a metal plate influences it's resistance seems therefore beyond doubt. What that influence is quantitatively at relevant structures I can't say exactly. Perhaps it is inconsequential as you suggest.

Irrespective, most theories suggest that thrust, if it exists, is related to Q. I think that measuring the value of Q in experiments is a good thing. Without that, we will have little idea whether a null result is due to lack of thrust or lack of experimental ability to discern a small expected effect.

Regards,

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Prunesquallor on 09/12/2015 04:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425380#msg1425380">Quote from: SeeShells on 09/12/2015 03:57 AM</a>
http://phys.org/news/2015-09-spacex-peek-crew-vehicle.html
This is one beautiful looking space vehicle.


He needs to stop his rockets from blowing up before he puts those pretty capsules on top of them.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/12/2015 05:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425510#msg1425510">Quote from: Prunesquallor on 09/12/2015 04:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425380#msg1425380">Quote from: SeeShells on 09/12/2015 03:57 AM</a>
http://phys.org/news/2015-09-spacex-peek-crew-vehicle.html
This is one beautiful looking space vehicle.


He needs to stop his rockets from blowing up before he puts those pretty capsules on top of them.
You got that right and with people in them too!

Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?

Anyway, I was thinking what Rf in a can could do, bounce around, get more energy from bouncing around and making heat and that seemed not enough until I wondered what happens sometimes when you pass a polarized wave through a set of particles? Could they become quantum entangled? I couldn't let it go and this morning I started searching on the net and came across this interesting test that was run. http://arstechnica.com/science/2011/01/10-billion-pairs-of-particles-entangled-with-single-radio-wave/
This still has me thinking and it's still forming, if this can happen in a frustum. What happens when one entangled particle collapses into evanescence,  evanescent electromagnetic waves can carry four distinct momenta and three distinct spin angular momenta. This is in sharp contrast with the single momentum and single spin for a propagating plane wave (photons)(1) and it's entangled to the other particle? They still are linked right? Will the non-decaying wave start to exhibit the same 3 distinct spin angular momenta and 4 momentas?

If this is the case would it not seem that we now have a traveling entangled photon in a wave carrying the extraordinary forces of the decaying evanescent wave? I wonder what abilities those extra forces if they are carried could have?

I need to catch a nap. Congatate on this and in my best (smiling) Arnold S. voice "I'll be back".

Shell
(1)http://arxiv.org/abs/1308.0547#

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Greg Pecchia on 09/12/2015 07:15 PM
Long time lurker, first time poster here.
I have an idea way out in left field: could microwave phase conjugation using antenna arrays be implemented to create resonance at any desired input frequencies?

Some reference.
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=734509&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel4%2F22%2F15815%2F00734509.pdf%3Farnumber%3D734509
http://www.hindawi.com/journals/ijap/2010/564357/
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sghill on 09/12/2015 09:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425567#msg1425567">Quote from: Greg Pecchia on 09/12/2015 07:15 PM</a>
Long time lurker, first time poster here.
I have an idea way out in left field: could microwave phase conjugation using antenna arrays be implemented to create resonance at any desired input frequencies?

Some reference.
http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=734509&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel4%2F22%2F15815%2F00734509.pdf%3Farnumber%3D734509
http://www.hindawi.com/journals/ijap/2010/564357/

And as someone who has worked with many phased array designs, I've wondered if steerable beams could be used to manage the sweet spot within the frustum. 

It's hard (but not impossible) with a waveguide, and impossible (IMHO) with loop antennas, but we haven't explored patch antennas attached to the interior of a frustum.  The D/A chipset is the magic here, and you need sensors within the frustum to tell the D/A chip where to steer the beam if there are differences between each device.

If each device is calculated separately (the approach this NSF group has been taking) beforehand, that's fine, but this new approach could work with any new device without exact pre-calculations.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/12/2015 09:39 PM
along those lines i think you would need a scanning type radar to get beam steering -or could you use the radars from an auto with collision avoidance radar (can you get those from an auto dealer, parts store or junk yard?) or a cannibalized polaroid camera?

the power though is likely too tiny from those types of gear.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/13/2015 07:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425395#msg1425395">Quote from: demofsky on 09/12/2015 05:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425208#msg1425208">Quote from: Rodal on 09/11/2015 09:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425186#msg1425186">Quote from: sghill on 09/11/2015 08:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425151#msg1425151">Quote from: demofsky on 09/11/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425084#msg1425084">Quote from: TheTraveller on 09/11/2015 04:55 PM</a>
2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

Great to see you back!!  :D

This is a very interesting insight into how Shawyer may now see this phenomena working.  It is almost like striking a bell!  Very, very interesting.  Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer.  Hm.

Would that explain the long duration drop off after the power is turned off?

No.

Have to agree with Rodal.  From a microwave perspective you are looking probably at nanoseconds (femtoseconds?) unless I am missing something.  Same thing would be true as far as I know for any ionized gasses rattling around.  Couldn't speak to how long a superconducting EM bell would ring on its own but it would likely still be much shorter than say a millisecond, if that.

The insight for me is that the EM Drive could possibly be best driven by a pulsed power source and not a continuous one.

That said, that long duration drop off is one of those signals that makes this such a tar patch.  It shows up in different experiments, usually explained away as either thermals or stiction in the measuring apparatus. 

Thing is, while thrust does not require new physics, this duration thing would if it is not just an experimental artifact...

Resonant cavities have a TC (Time Constant) which defines the rate of energy increase or decrease. Is defined as

TC = (2 QL) / ( 2 Pi Freq).

For a SC cavity with a unloaded Q0 of 5,000,0000 and a loaded QL of 1,000,000 due to an antenna coupling factor of 0.20. QL = Q0 * antenna coupling factor, the excitation period TC is then 130us and the post excitation TC (no phase distortion from the excitation antenna's EM waves on the internal resonant wave) climbs to 650us. All at 2.45GHz.

Which would suggest the cavity can maintain the pure, non phase distorted, resonant EM waves for quite some period alter the excitation, cavity fill EM pulse is stopped.

Also suggests the antenna coupling factor is not as important as is getting an ideal impedance match to drop the frustum VSWR to as close to as 1:1 as possible.

I would again point out the use of a feed slit on the frustum side wall. To me this suggests a desire for an excitation method that will have minimal effect on the post excitation non loaded Q. Sort of how to have a RF in feed capability but not upset the frustum mechanics, smooth side wall, to obtain max non loaded Q post the excitation period.

Using the side wall slit and doing short 20% of 1 TC RF excitation pulses is a clever way to eliminate antenna coupling factor dequeuing the frustum post excitation Q and to eliminate the excitation antenna being a permanent feature inside the cavity.

At 900MHz the above 1 TC times lengthen to

Excited TC = 354us
Nonexcited TC = 1.77ms

Attached drawing shows the 20% of 1 TC excitation RF period that Shawyer mentions in his patent.

Also is attached data from his peer reviewed paper, showing the time of the pulse, and how the Force generated declines as the mainly TC driven resonant EM standing waves inside the cavity decline in strength.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/13/2015 10:27 PM
Uh-oh...LDS display that was supposed to be working was not...bummer
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheUberOverLord on 09/13/2015 10:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425890#msg1425890">Quote from: rfmwguy on 09/13/2015 10:27 PM</a>
Uh-oh...LDS display that was supposed to be working was not...bummer

Seems more like the LCD ("Liquid Crystal Display") is working and is simply reporting an error from the device the LCD is connected to.

You many want to contact the seller and supply the picture. There could be a solution without the need to return the device.

Don

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/14/2015 02:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425897#msg1425897">Quote from: TheUberOverLord on 09/13/2015 10:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425890#msg1425890">Quote from: rfmwguy on 09/13/2015 10:27 PM</a>
Uh-oh...LDS display that was supposed to be working was not...bummer

Seems more like the LCD ("Liquid Crystal Display") is working and is simply reporting an error from the device the LCD is connected to.

You many want to contact the seller and supply the picture. There could be a solution without the need to return the device.

Don
I downloaded the manual and discovered the error code was a "Memory Error". It said to plug it in several times to see if it goes away. It did not. Also tried Reset and Zero signalllls without success. Good news is laser displacement sensor seems to be fine, just a problem with the display. Sent the seller a note and I'm sure they will help. Just hate delays.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zen-in on 09/14/2015 04:01 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425937#msg1425937">Quote from: rfmwguy on 09/14/2015 02:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425897#msg1425897">Quote from: TheUberOverLord on 09/13/2015 10:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425890#msg1425890">Quote from: rfmwguy on 09/13/2015 10:27 PM</a>
Uh-oh...LDS display that was supposed to be working was not...bummer

Seems more like the LCD ("Liquid Crystal Display") is working and is simply reporting an error from the device the LCD is connected to.

You many want to contact the seller and supply the picture. There could be a solution without the need to return the device.

Don
I downloaded the manual and discovered the error code was a "Memory Error". It said to plug it in several times to see if it goes away. It did not. Also tried Reset and Zero signalllls without success. Good news is laser displacement sensor seems to be fine, just a problem with the display. Sent the seller a note and I'm sure they will help. Just hate delays.

There may be some configuration tables that need to be initialized.   It looks like one of those problems that turns out to be trivial once you find the solution.  deja-vous all over again.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CW on 09/14/2015 11:24 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425518#msg1425518">Quote from: SeeShells on 09/12/2015 05:03 PM</a>
[..]

Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?

I'd rather say, your mind is going too fast for other people your age.
:)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/14/2015 01:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425994#msg1425994">Quote from: CW on 09/14/2015 11:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425518#msg1425518">Quote from: SeeShells on 09/12/2015 05:03 PM</a>
[..]

Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?

I'd rather say, your mind is going too fast for other people your age.
:)
I'm glad everyone puts up with my mind flights of fancy, been that way most of my life. Trying to figure out the whys of something. I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.

Got tired (way too much time spent on it) of trying to make the cheap lasers work and couldn't get a good "dot" on my graph paper even using pin hole lenses, they wanted to degrade to a fringing splat on the paper around 30 feet, maybe that is why they were so inexpensive?. So I'm going to try something a little different.  http://www.ebay.com/itm/131597609908 and strap and align and focus it right on the far end of the flucrum,  about 5 meters from the laser to the paper.

 

Shell

Added: And after all this work if the frustum proves too frustrating I'll just change my EMDrive into a thermally agitated dihydrogen monoxide machine.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: D_Dom on 09/14/2015 04:59 PM
SteamPunkt!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: VAXHeadroom on 09/14/2015 06:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426015#msg1426015">Quote from: SeeShells on 09/14/2015 01:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425994#msg1425994">Quote from: CW on 09/14/2015 11:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425518#msg1425518">Quote from: SeeShells on 09/12/2015 05:03 PM</a>
[..]

Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?

I'd rather say, your mind is going too fast for other people your age.
:)
I'm glad everyone puts up with my mind flights of fancy, been that way most of my life. Trying to figure out the whys of something. I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.

Got tired (way too much time spent on it) of trying to make the cheap lasers work and couldn't get a good "dot" on my graph paper even using pin hole lenses, they wanted to degrade to a fringing splat on the paper around 30 feet, maybe that is why they were so inexpensive?. So I'm going to try something a little different.  http://www.ebay.com/itm/131597609908 and strap and align and focus it right on the far end of the flucrum,  about 5 meters from the laser to the paper.

 

Shell

Added: And after all this work if the frustum proves too frustrating I'll just change my EMDrive into a thermally agitated dihydrogen monoxide machine.

I have a 5mw HeNe laser I can loan you...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/14/2015 06:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426106#msg1426106">Quote from: VAXHeadroom on 09/14/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426015#msg1426015">Quote from: SeeShells on 09/14/2015 01:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425994#msg1425994">Quote from: CW on 09/14/2015 11:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425518#msg1425518">Quote from: SeeShells on 09/12/2015 05:03 PM</a>
[..]

Last night was a long sleepless night for whatever reason, mind going to fast for my age at least. Something dawned on me in the middle of the night, can you call it night dreaming instead of day dreaming and still be correct?

I'd rather say, your mind is going too fast for other people your age.
:)
I'm glad everyone puts up with my mind flights of fancy, been that way most of my life. Trying to figure out the whys of something. I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.

Got tired (way too much time spent on it) of trying to make the cheap lasers work and couldn't get a good "dot" on my graph paper even using pin hole lenses, they wanted to degrade to a fringing splat on the paper around 30 feet, maybe that is why they were so inexpensive?. So I'm going to try something a little different.  http://www.ebay.com/itm/131597609908 and strap and align and focus it right on the far end of the flucrum,  about 5 meters from the laser to the paper.

 

Shell

Added: And after all this work if the frustum proves too frustrating I'll just change my EMDrive into a thermally agitated dihydrogen monoxide machine.

I have a 5mw HeNe laser I can loan you...

Thanks! Let's see what I can get out of these one I ordered, if it turns out  unusable then I might take you up on it.

Sorry for not posting as much but my time is being spent on trying to get my mom's estate closed out and .... families are.... sigh, well families. Plus, I want to get this build finished.

Thanks again!

Shell



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/14/2015 06:56 PM

Hmm, so 10us is too short but 200us shots might actually be better than continuous at 900MHz?

Well, 20% 70us.... so 10us you might actually see something??


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425698#msg1425698">Quote from: TheTraveller on 09/13/2015 07:44 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425395#msg1425395">Quote from: demofsky on 09/12/2015 05:33 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425208#msg1425208">Quote from: Rodal on 09/11/2015 09:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425186#msg1425186">Quote from: sghill on 09/11/2015 08:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425151#msg1425151">Quote from: demofsky on 09/11/2015 07:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425084#msg1425084">Quote from: TheTraveller on 09/11/2015 04:55 PM</a>
2) I believe the 2nd image is very important. Here Shawyer excites the frustum for only about 20% of 1 TC being (2Q)/(2 pi f) seconds. This means any phase distortion introduced in the resonant standing wave, during the short 20% of 1 TC excitation period, will stop after the excitation stops and the full non phase distorted internal EM resonant wave will be allowed to form and gen max Force. It may be that Shawyer found continual excitation only results in low Force generation due to RF feed introduced phase distortion. Another plus for solid state RF amps that can be switched on and off VERY quickly.

Great to see you back!!  :D

This is a very interesting insight into how Shawyer may now see this phenomena working.  It is almost like striking a bell!  Very, very interesting.  Also may explain why magnetrons seem to work because of their duty cycle acting as an impromptu bell ringer.  Hm.

Would that explain the long duration drop off after the power is turned off?

No.

Have to agree with Rodal.  From a microwave perspective you are looking probably at nanoseconds (femtoseconds?) unless I am missing something.  Same thing would be true as far as I know for any ionized gasses rattling around.  Couldn't speak to how long a superconducting EM bell would ring on its own but it would likely still be much shorter than say a millisecond, if that.

The insight for me is that the EM Drive could possibly be best driven by a pulsed power source and not a continuous one.

That said, that long duration drop off is one of those signals that makes this such a tar patch.  It shows up in different experiments, usually explained away as either thermals or stiction in the measuring apparatus. 

Thing is, while thrust does not require new physics, this duration thing would if it is not just an experimental artifact...

Resonant cavities have a TC (Time Constant) which defines the rate of energy increase or decrease. Is defined as

TC = (2 QL) / ( 2 Pi Freq).

For a SC cavity with a unloaded Q0 of 5,000,0000 and a loaded QL of 1,000,000 due to an antenna coupling factor of 0.20. QL = Q0 * antenna coupling factor, the excitation period TC is then 130us and the post excitation TC (no phase distortion from the excitation antenna's EM waves on the internal resonant wave) climbs to 650us. All at 2.45GHz.

Which would suggest the cavity can maintain the pure, non phase distorted, resonant EM waves for quite some period alter the excitation, cavity fill EM pulse is stopped.

Also suggests the antenna coupling factor is not as important as is getting an ideal impedance match to drop the frustum VSWR to as close to as 1:1 as possible.

I would again point out the use of a feed slit on the frustum side wall. To me this suggests a desire for an excitation method that will have minimal effect on the post excitation non loaded Q. Sort of how to have a RF in feed capability but not upset the frustum mechanics, smooth side wall, to obtain max non loaded Q post the excitation period.

Using the side wall slit and doing short 20% of 1 TC RF excitation pulses is a clever way to eliminate antenna coupling factor dequeuing the frustum post excitation Q and to eliminate the excitation antenna being a permanent feature inside the cavity.

At 900MHz the above 1 TC times lengthen to

Excited TC = 354us
Nonexcited TC = 1.77ms

Attached drawing shows the 20% of 1 TC excitation RF period that Shawyer mentions in his patent.

Also is attached data from his peer reviewed paper, showing the time of the pulse, and how the Force generated declines as the mainly TC driven resonant EM standing waves inside the cavity decline in strength.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/14/2015 07:01 PM
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/14/2015 07:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426141#msg1426141">Quote from: Rodal on 09/14/2015 07:01 PM</a>
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
We are getting there, Doc...slow but sure. It takes time on a home budget, but my personal goal of adding to the data will be accomplished soon. Proving or disproving, its all the same to me...I've enjoyed the build and commaraderie to date.

p.s. Good Canadian seller of (defective) K3NX LDS display controller. Immediately issued refund and didn't bother with asking me to return it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/14/2015 08:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426141#msg1426141">Quote from: Rodal on 09/14/2015 07:01 PM</a>
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
And you wonder why I'm being picky?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/14/2015 09:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426141#msg1426141">Quote from: Rodal on 09/14/2015 07:01 PM</a>
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
l
Well if I used dimensions meant for a 900mhz rf source with a 2.45ghz rf source to test a theory involving "and the Q is important" I'm not sure it bricking is going to tell me much useful information. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/14/2015 10:42 PM
Sorry for late notice...I'll be back on Mr Hoagland's Other Side of Midnight show this evening at 12 Midnight Pacific Daylight Time.

The first hour will be a status review of the NSF-1701 project and we will be taking callers at 1 AM.

Everyone is invited to call in, believers and skeptics: http://othersideofmidnight.com
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/14/2015 10:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426205#msg1426205">Quote from: SteveD on 09/14/2015 09:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426141#msg1426141">Quote from: Rodal on 09/14/2015 07:01 PM</a>
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
l
Well if I used dimensions meant for a 900mhz rf source with a 2.45ghz rf source to test a theory involving "and the Q is important" I'm not sure it bricking is going to tell me much useful information.

On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/15/2015 01:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426228#msg1426228">Quote from: Rodal on 09/14/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426205#msg1426205">Quote from: SteveD on 09/14/2015 09:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426141#msg1426141">Quote from: Rodal on 09/14/2015 07:01 PM</a>
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
l
Well if I used dimensions meant for a 900mhz rf source with a 2.45ghz rf source to test a theory involving "and the Q is important" I'm not sure it bricking is going to tell me much useful information.

On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.

True, that said I remain relatively sure that taking a frustum designed for a 900 (and change) mhz industrial magnetron, hooking a 2.45 Ghz consumer magnetron to it via coax feed of a random length and expecting it to do something without any further tuning (except burn a potato), is probably not the way to go. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/15/2015 03:01 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426228#msg1426228">Quote from: Rodal on 09/14/2015 10:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426205#msg1426205">Quote from: SteveD on 09/14/2015 09:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426141#msg1426141">Quote from: Rodal on 09/14/2015 07:01 PM</a>
Yet another report from a DIY experiment showing NO thrust from an EM Drive and instead reporting thermal effects:  https://www.reddit.com/r/EmDrive/comments/3kxvjr/emdrive_build_update_5/

Absolutely no one, has ever replicated the claims of Shawyer and Yang (who never reported a single test performed in vacuum and therefore never properly accounted for thermal effects).
l
Well if I used dimensions meant for a 900mhz rf source with a 2.45ghz rf source to test a theory involving "and the Q is important" I'm not sure it bricking is going to tell me much useful information.

On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.
Pick any one of the frequencies out of a consumer magnetron to start,  but first figure out whether it's driven by a single HV diode @ 220 VAC 50 Hz or a 220 VAC Inverter @ 50 Hz (South Africa's power grid is 220VAC @ 50 Hz). If it's a single HV Diode PS driving it then the range for harmonics and shifting frequencies will be greater than a Inverter which operating frequencies should be on the order of 20 KHz into the HV coil and a more stable output.

Whether his magnetron will provide a output that excites the frustum is anyone's good guess considering these two facts. There is no bad data. He gets a A for doing it.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/15/2015 03:08 AM
Got the new magnetron and inverter late this afternoon (yea!!!), been waiting for a long time it seems. Tomorrow I'll start to get the inverter power supply and magnetron mounted on the Aluminum plate and wiring it. I still need to build a 555 timer to provide a data good signal to switch on the inverter without the front panel controls.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 09/15/2015 02:12 PM
What I learned this week:

Most replacement magnetrons have an advertised frequency center at 2460, not 2450.

A standard non-inverter microwave on 60hz power produces 4250v pulses at twice the line frequency, on for 8.3 ms, off for 8.3 ms.

With 2 caps and another diode you can replace the https://en.wikipedia.org/wiki/Voltage_doubler#Villard_circuit output stage with a https://en.wikipedia.org/wiki/Voltage_doubler#Greinacher_circuit .  This provides continuous power output instead of pulsed.

You MUST cut the leads to the heater and supply power to them separately before running the magnetron grid on DC.  The heater uses an RF choke to pull the HV down to 3-4 volts DC in a stock mangetron.  Running 4.3kv through it will kill it and possibly you.

You can use oven diodes for this, but the oven caps aren't rated for the voltage.  I found 10kv film capacitors on ebay for <$25.  For safety add bleeder resistors to these caps.

Now I have a new question:  How can I further change the output voltage and/or current limit this?  That's this week's project.

Thanks in advance for the advice.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/15/2015 03:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426364#msg1426364">Quote from: ElizabethGreene on 09/15/2015 02:12 PM</a>
What I learned this week:

Most replacement magnetrons have an advertised frequency center at 2460, not 2450.

A standard non-inverter microwave on 60hz power produces 4250v pulses at twice the line frequency, on for 8.3 ms, off for 8.3 ms.

With 2 caps and another diode you can replace the https://en.wikipedia.org/wiki/Voltage_doubler#Villard_circuit output stage with a https://en.wikipedia.org/wiki/Voltage_doubler#Greinacher_circuit .  This provides continuous power output instead of pulsed.

You can use oven diodes for this, but the oven caps aren't rated for the voltage.  I found 10kv film capacitors on ebay for <$25.  For safety add bleeder resistors to these caps.

Now I have a new question:  How can I further change the output voltage and/or current limit this?  That's this week's project.

Thanks in advance for the advice.
You have a schematic of your power supply?
Shell
Here is one way.
http://www.google.com/patents/US4383156

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 09/15/2015 06:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426405#msg1426405">Quote from: SeeShells on 09/15/2015 03:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426364#msg1426364">Quote from: ElizabethGreene on 09/15/2015 02:12 PM</a>
What I learned this week:

Most replacement magnetrons have an advertised frequency center at 2460, not 2450.

A standard non-inverter microwave on 60hz power produces 4250v pulses at twice the line frequency, on for 8.3 ms, off for 8.3 ms.

With 2 caps and another diode you can replace the https://en.wikipedia.org/wiki/Voltage_doubler#Villard_circuit output stage with a https://en.wikipedia.org/wiki/Voltage_doubler#Greinacher_circuit .  This provides continuous power output instead of pulsed.

You can use oven diodes for this, but the oven caps aren't rated for the voltage.  I found 10kv film capacitors on ebay for <$25.  For safety add bleeder resistors to these caps.

Now I have a new question:  How can I further change the output voltage and/or current limit this?  That's this week's project.

Thanks in advance for the advice.
You have a schematic of your power supply?
Shell

No, I'll draw one when I get home.

I didn't mention that you must -must- cut the leads to the filament heater before running the magnetron DC. 
  I'll edit that immediately.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 09/15/2015 08:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426015#msg1426015">Quote from: SeeShells on 09/14/2015 01:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425994#msg1425994">Quote from: CW on 09/14/2015 11:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425518#msg1425518">Quote from: SeeShells on 09/12/2015 05:03 PM</a>
[..]


I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.


Being half baked is a prudent path to avoid being burnt.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/15/2015 08:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426520#msg1426520">Quote from: Bob Woods on 09/15/2015 08:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426015#msg1426015">Quote from: SeeShells on 09/14/2015 01:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425994#msg1425994">Quote from: CW on 09/14/2015 11:24 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1425518#msg1425518">Quote from: SeeShells on 09/12/2015 05:03 PM</a>
[..]


I hope all realize I'm just using this forum as a sounding board for my half baked thoughts sometimes and what ifs or has anyone taken it into account.


Being half baked is a prudent path to avoid being burnt.
Sometimes it's hard to swallow half baked too.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 09/16/2015 04:55 AM
Never!

I can't claim to be a scientist as much as I would like to be able to. I did some ground breaking programming while in government. But few people saw the ground.  ;D

You're probably as near old as me. Possibly you remember this from college:

"Behold the turtle. They only make progress when they stick their heads out."

(Revised to compensate for 1970's sexism.)

Bob
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/16/2015 01:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426697#msg1426697">Quote from: Bob Woods on 09/16/2015 04:55 AM</a>
Never!

I can't claim to be a scientist as much as I would like to be able to. I did some ground breaking programming while in government. But few people saw the ground.  ;D

You're probably as near old as me. Possibly you remember this from college:

"Behold the turtle. They only make progress when they stick their heads out."

(Revised to compensate for 1970's sexism.)

Bob
Hehe, haven't heard that one in 45 years Bob. And we know which one won that classic race, between the Tortoise and the Hare.

Shell



 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/16/2015 02:06 PM
New emdrive build head's up:

https://www.reddit.com/r/EmDrive/comments/3l4clo/emdrive_build_update_version_001/

Interesting test bed configuration; he's just getting started. Laser powered rather than magnetron. A little different, but hey, everyone has a right to start somewhere. Should be interesting!

NSF-1701 Update: New LDS display meter on its way. Will be installing it into an old PC where I'll use its power supply to fire up the LDS and also DAQ inputs. The display is simply a good visual tool, the DAQ will give me the tabular data for chart creating, etc.

I also will be experimenting around with labview or its open source equivalent. Figure an old PC is fine for DAQ stuff, but am still cautious about relying on it too much in high EM fields...thus the shielded LDS display module which is designed to work in tough industrial environments, heat, vibration, EM fields, etc.,
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/16/2015 02:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426784#msg1426784">Quote from: rfmwguy on 09/16/2015 02:06 PM</a>
New emdrive build head's up:

https://www.reddit.com/r/EmDrive/comments/3l4clo/emdrive_build_update_version_001/

Interesting test bed configuration; he's just getting started. Laser powered rather than magnetron. A little different, but hey, everyone has a right to start somewhere. Should be interesting!

NSF-1701 Update: New LDS display meter on its way. Will be installing it into an old PC where I'll use its power supply to fire up the LDS and also DAQ inputs. The display is simply a good visual tool, the DAQ will give me the tabular data for chart creating, etc.

I also will be experimenting around with labview or its open source equivalent. Figure an old PC is fine for DAQ stuff, but am still cautious about relying on it too much in high EM fields...thus the shielded LDS display module which is designed to work in tough industrial environments, heat, vibration, EM fields, etc.,

take a look at this:  http://www.myopenlab.de/startseite/downloads.html

Documentation is in German and Spanish, but the installer permits a choice of English.  If you speak German or Spanish, you're home free. 

English forum:  http://myopenlab.informe.com/myopenlab-english-df1.html

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/16/2015 07:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426791#msg1426791">Quote from: glennfish on 09/16/2015 02:24 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426784#msg1426784">Quote from: rfmwguy on 09/16/2015 02:06 PM</a>
New emdrive build head's up:

https://www.reddit.com/r/EmDrive/comments/3l4clo/emdrive_build_update_version_001/

Interesting test bed configuration; he's just getting started. Laser powered rather than magnetron. A little different, but hey, everyone has a right to start somewhere. Should be interesting!

NSF-1701 Update: New LDS display meter on its way. Will be installing it into an old PC where I'll use its power supply to fire up the LDS and also DAQ inputs. The display is simply a good visual tool, the DAQ will give me the tabular data for chart creating, etc.

I also will be experimenting around with labview or its open source equivalent. Figure an old PC is fine for DAQ stuff, but am still cautious about relying on it too much in high EM fields...thus the shielded LDS display module which is designed to work in tough industrial environments, heat, vibration, EM fields, etc.,

take a look at this:  http://www.myopenlab.de/startseite/downloads.html

Documentation is in German and Spanish, but the installer permits a choice of English.  If you speak German or Spanish, you're home free. 

English forum:  http://myopenlab.informe.com/myopenlab-english-df1.html
Thanks! Will download this tonight. Have a 10=bit A/D module coming in as well as the new LDS display in a few days.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/16/2015 08:18 PM
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

https://www.youtube.com/watch?v=MxhT5_Hh2CA
some more vids are available
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/16/2015 11:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

...
some more vids are available

Interesting video...
So all we have to do is pressurize a cone and heat it up, and we should get a net thrust?  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 09/17/2015 02:08 AM
OK, an extension:

Behold the oyster. You only get the pearl when the Shell opens up.

Find that thrust. Try and try again. Then repeat.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/17/2015 02:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427015#msg1427015">Quote from: Bob Woods on 09/17/2015 02:08 AM</a>
OK, an extension:

Behold the oyster. You only get the pearl when the Shell opens up.

Find that thrust. Try and try again. Then repeat.
urk. You bet Bob, I'm not Shell Shocked.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 09/17/2015 02:58 AM

Hmm...

Quote
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

1 - One of my first posts here (way back in thread one) dealt with this - that the EM Drive moved on account of its shape.

2 - I was told the concept violated the laws of thermodynamics.  So, given that, are these simulations legit?

Ok, thought experiment.  Say we use actual physical objects instead of photons.  maybe old fashioned 'super balls' or something similar, though unlike photons they would slow down.  A frustum in a zero G environment.  Would the results match the simulation? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 09/17/2015 03:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426982#msg1426982">Quote from: zellerium on 09/16/2015 11:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

...
some more vids are available

Interesting video...
So all we have to do is pressurize a cone and heat it up, and we should get a net thrust?  :o

Back in thread three this was discussed briefly in the context of ionized particles.  Yang stated in one of her papers that the behaviour of ionized particles was important to understanding the behaviour of EM Drives.  It has been pointed out numerous times that neither Yang or Shawyer published experiments ran in vacuum.

At one point I called this the "ionic wind tunnel" effect in those discussions.  That said, these were general discussions and everyone felt that microwave energy was the primary source for trust...

Now we have some excellent simulations that bring this all back.  Note that, say, nitrogen ions are orders of magnitude more massive than photons.

In my view, these simulations are a significant step forward in our understanding of this phenomena.  Congratulations!

And once again I am in awe of the power of these forums! :D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/17/2015 05:53 AM
@SeeShells,

Here are some views of the CE3 model. They are very preliminary but ... well, its as far as I have gotten.

https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing)

It resonates but it's not a mode that I recognize.

Specifics-
Cavity is the SeeShell Crazy Eddie 2, upgraded by replacing the loop antenna with wave guides, hence CE3 model.
Drive frequency 2.47 GHz, Harminv calculated resonant frequency 2.47837658E+009 Hz, Q is good: ~ 1 million.
Antenna - dual magnetron wave guides, 180 degrees apart. That is, on opposite sides of the frustum using WR 340 wave guides with bottom edge flush with the big base. Phase is adjusted to place sources 3 wavelengths apart.
Gaussian noise bandwidth at 0.05 * 2.47GHz is is double the expected magnetron noise bandwidth.

This is a debug run at resolution = 200, hence it may appear more granular than the resolution = 250 runs commonly uploaded. There are no csv files, resolution of 200 would adversely affect any data comparison calculations based on the csv files.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/17/2015 06:50 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427035#msg1427035">Quote from: aero on 09/17/2015 05:53 AM</a>
@SeeShells,

Here are some views of the CE3 model. They are very preliminary but ... well, its as far as I have gotten.

https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing)

It resonates but it's not a mode that I recognize.

Specifics-
Cavity is the SeeShell Crazy Eddie 2, upgraded by replacing the loop antenna with wave guides, hence CE3 model.
Drive frequency 2.47 GHz, Harminv calculated resonant frequency 2.47837658E+009 Hz, Q is good: ~ 1 million.
Antenna - dual magnetron wave guides, 180 degrees apart. That is, on opposite sides of the frustum using WR 340 wave guides with bottom edge flush with the big base. Phase is adjusted to place sources 3 wavelengths apart.
Gaussian noise bandwidth at 0.05 * 2.47GHz is is double the expected magnetron noise bandwidth.

This is a debug run at resolution = 200, hence it may appear more granular than the resolution = 250 runs commonly uploaded. There are no csv files, resolution of 200 would adversely affect any data comparison calculations based on the csv files.

Great to see you got the waveguide injection working aero.

It looks like you placed the wave right on the bottom to replace the antennas,

If you look at the mode generation in the attached image...
You'll see close to the middle of the frustum is where the mode wants to generate within the frustum. Did you try to do the waveguides insertion at that point? We should try.

Shell

Move the waveguides up to the point where they are not inserting into the frustum which should be halfway up. See image.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/17/2015 01:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427024#msg1427024">Quote from: demofsky on 09/17/2015 03:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426982#msg1426982">Quote from: zellerium on 09/16/2015 11:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

...
some more vids are available

Interesting video...
So all we have to do is pressurize a cone and heat it up, and we should get a net thrust?  :o

Back in thread three this was discussed briefly in the context of ionized particles.  Yang stated in one of her papers that the behaviour of ionized particles was important to understanding the behaviour of EM Drives.  It has been pointed out numerous times that neither Yang or Shawyer published experiments ran in vacuum.

At one point I called this the "ionic wind tunnel" effect in those discussions.  That said, these were general discussions and everyone felt that microwave energy was the primary source for trust...

Now we have some excellent simulations that bring this all back.  Note that, say, nitrogen ions are orders of magnitude more massive than photons.

In my view, these simulations are a significant step forward in our understanding of this phenomena.  Congratulations!

And once again I am in awe of the power of these forums! :D
I might have been part of that ionized conversation. I noticed a metallic "feel" to the air after power testing which someone proposed as copper ionization. It could be Ni, but it seemed "metallic", if I might used that term. This was noticed on all 3 Flight Tests I did in August. FWIW, I know its not exactly a scientific description, just an impression.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/17/2015 02:21 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427089#msg1427089">Quote from: rfmwguy on 09/17/2015 01:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427024#msg1427024">Quote from: demofsky on 09/17/2015 03:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426982#msg1426982">Quote from: zellerium on 09/16/2015 11:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

...
some more vids are available

Interesting video...
So all we have to do is pressurize a cone and heat it up, and we should get a net thrust?  :o

Back in thread three this was discussed briefly in the context of ionized particles.  Yang stated in one of her papers that the behaviour of ionized particles was important to understanding the behaviour of EM Drives.  It has been pointed out numerous times that neither Yang or Shawyer published experiments ran in vacuum.

At one point I called this the "ionic wind tunnel" effect in those discussions.  That said, these were general discussions and everyone felt that microwave energy was the primary source for trust...

Now we have some excellent simulations that bring this all back.  Note that, say, nitrogen ions are orders of magnitude more massive than photons.

In my view, these simulations are a significant step forward in our understanding of this phenomena.  Congratulations!

And once again I am in awe of the power of these forums! :D
I might have been part of that ionized conversation. I noticed a metallic "feel" to the air after power testing which someone proposed as copper ionization. It could be Ni, but it seemed "metallic", if I might used that term. This was noticed on all 3 Flight Tests I did in August. FWIW, I know its not exactly a scientific description, just an impression.
Ni? Why Nickel?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/17/2015 02:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427107#msg1427107">Quote from: SeeShells on 09/17/2015 02:21 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427089#msg1427089">Quote from: rfmwguy on 09/17/2015 01:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427024#msg1427024">Quote from: demofsky on 09/17/2015 03:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426982#msg1426982">Quote from: zellerium on 09/16/2015 11:34 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

...
some more vids are available

Interesting video...
So all we have to do is pressurize a cone and heat it up, and we should get a net thrust?  :o

Back in thread three this was discussed briefly in the context of ionized particles.  Yang stated in one of her papers that the behaviour of ionized particles was important to understanding the behaviour of EM Drives.  It has been pointed out numerous times that neither Yang or Shawyer published experiments ran in vacuum.

At one point I called this the "ionic wind tunnel" effect in those discussions.  That said, these were general discussions and everyone felt that microwave energy was the primary source for trust...

Now we have some excellent simulations that bring this all back.  Note that, say, nitrogen ions are orders of magnitude more massive than photons.

In my view, these simulations are a significant step forward in our understanding of this phenomena.  Congratulations!

And once again I am in awe of the power of these forums! :D
I might have been part of that ionized conversation. I noticed a metallic "feel" to the air after power testing which someone proposed as copper ionization. It could be Ni, but it seemed "metallic", if I might used that term. This was noticed on all 3 Flight Tests I did in August. FWIW, I know its not exactly a scientific description, just an impression.
Ni? Why Nickel?

Shell
Ooooops, N not Ni  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/17/2015 02:37 PM
As a backup to the digital meter made for the LDS, I am using a basic, 10-bit A/D converter. Here it is:

http://www.dataq.com/products/di-145/

This is a USB interface and easy to use. It measures up to +/- 10 VDC and the LDS is about +/- 5 VDC. It will datalog and can provide a simple graphic display on vertical displacement at a sample rate of about 4 msec (240 Hz). The LDS has a sample rate of about 3 msec, so it matches up fairly well.

Any downward force that might briefly appear (counteracting thermal lift) should be able to be picked up in this time frame. Also, any "stickiness" or pivoting errors should also show up. We'll see in a few days.

I would encourage experimenters to datalog with this simple box as a backup to other measurement methods such as laser spots or digital displays. FWIW...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/17/2015 04:17 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427021#msg1427021">Quote from: ThinkerX on 09/17/2015 02:58 AM</a>
Hmm...

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

https://www.youtube.com/watch?v=MxhT5_Hh2CA
some more vids are available

1 - One of my first posts here (way back in thread one) dealt with this - that the EM Drive moved on account of its shape.

2 - I was told the concept violated the laws of thermodynamics.  So, given that, are these simulations legit?

Ok, thought experiment.  Say we use actual physical objects instead of photons.  maybe old fashioned 'super balls' or something similar, though unlike photons they would slow down.  A frustum in a zero G environment.  Would the results match the simulation?

To answer your question:
Quote
So, given that, are these simulations legit?

No, these simulations are not legit.  A frustum in a zero G environment would not have results that match the simulation.

Exactly what when wrong in the simulation, I couldn't say without seeing everything he did to the settings, etc.  But the results are completely nonphysical and don't correspond to the real world.

Just intuitively, a bunch of non-zero momentum particles bouncing around in an asymetric cavity isn't a rare system.  Such systems exist everywhere.  Even the most energetic photons have negligible momentum if we compare them to your average gas particle at STP.  So if this simulation was legitimate (which it isn't), then a coke bottle filled with air or your average household balloon ought to be rocketing around with orders of magnitude better thrust than an emdrive.

I'm not going to take the time to flesh out the solution to such a problem mathematically, but it isn't difficult.  The case of infinitely many particles is equivalent to the uniform pressure case, and a person only needs some trig to be able to solve it.  In fact, the intuition of the problem is simple and shows the issue with what the youtube poster believes is happening.

In the video, he says that because the walls of the cone are angled off the plane of the horizontally flat base, only some of the force they experience when struck by a particle is in the vertical direction.  This is correct, but it does not lead to any net movement in the vertical direction because the angled walls also have a greater area than the horizontal base.  While one bounce against the flat base creates a greater vertical force than a bounce off the angled side walls, the fact that there is greater chance to hit a side wall than there is the top base due to the greater area perfectly cancels, so there is no net force over time.

If that wasn't enough, also realize that the simulation showed the drive moving towards the direction of the "big" base, which is opposite the direction the emdrive is supposed to go.

So if anything, these simulations are a case study in how you need to have a proper understanding of first principles to tell whether or not your simulations are correct.     

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/17/2015 04:34 PM

Dr. Rodal, you lost me there. I thought that the EM-Drive/Q-Thruster phenomena was linked to the concept that the frustrum had to be at the exact resonance mode (i.e. a frustrum at TE013 at 900MHz would NOT be at TE013 at 2.45GHz and thus would NOT have the same thrust??). Is not a concern  in these experiments the question of how exact do you have to be to achieve resonance mode as oppose to simply resonating (to fluidize the quantum vacuum or whatever)?? Indeed with our ANSYS modelling we are finding that the cavity part itself is not so hard, but we've found it to be non-trivial in the way the rf needs to be launched into the cavity.... more complicated is the fact that we want to be able to try firing RF into the large side and be able to switch to the smaller side... though I guess the easiest choice is into the side.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426228#msg1426228">Quote from: Rodal on 09/14/2015 10:59 PM</a>

On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/17/2015 05:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427041#msg1427041">Quote from: SeeShells on 09/17/2015 06:50 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427035#msg1427035">Quote from: aero on 09/17/2015 05:53 AM</a>
@SeeShells,

Here are some views of the CE3 model. They are very preliminary but ... well, its as far as I have gotten.

https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing)

It resonates but it's not a mode that I recognize.

Specifics-
Cavity is the SeeShell Crazy Eddie 2, upgraded by replacing the loop antenna with wave guides, hence CE3 model.
Drive frequency 2.47 GHz, Harminv calculated resonant frequency 2.47837658E+009 Hz, Q is good: ~ 1 million.
Antenna - dual magnetron wave guides, 180 degrees apart. That is, on opposite sides of the frustum using WR 340 wave guides with bottom edge flush with the big base. Phase is adjusted to place sources 3 wavelengths apart.
Gaussian noise bandwidth at 0.05 * 2.47GHz is is double the expected magnetron noise bandwidth.

This is a debug run at resolution = 200, hence it may appear more granular than the resolution = 250 runs commonly uploaded. There are no csv files, resolution of 200 would adversely affect any data comparison calculations based on the csv files.

Great to see you got the waveguide injection working aero.

It looks like you placed the wave right on the bottom to replace the antennas,

If you look at the mode generation in the attached image...
You'll see close to the middle of the frustum is where the mode wants to generate within the frustum. Did you try to do the waveguides insertion at that point? We should try.

Shell

Move the waveguides up to the point where they are not inserting into the frustum which should be halfway up. See image.

Just to be clear on this point, the wave guides do not insert into the frustum. They are placed then cut cleanly at the inside surface of the frustum. The image shows that cut in the frustum cone as projected in the 2-D image of the 3-D object.  Not sure how you would actually construct them that way, but it is quite easy to model.

As currently modelled the wave guides are offset in z from the frustum exact center by -3.852 mm toward the big base. That aligns the bottom inside surface of the WR 340 with the inside surface of the big base. I will change that offset to zero from the frustum center and see what happens.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/17/2015 06:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427178#msg1427178">Quote from: aero on 09/17/2015 05:09 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427041#msg1427041">Quote from: SeeShells on 09/17/2015 06:50 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427035#msg1427035">Quote from: aero on 09/17/2015 05:53 AM</a>
@SeeShells,

Here are some views of the CE3 model. They are very preliminary but ... well, its as far as I have gotten.

https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing)

It resonates but it's not a mode that I recognize.

Specifics-
Cavity is the SeeShell Crazy Eddie 2, upgraded by replacing the loop antenna with wave guides, hence CE3 model.
Drive frequency 2.47 GHz, Harminv calculated resonant frequency 2.47837658E+009 Hz, Q is good: ~ 1 million.
Antenna - dual magnetron wave guides, 180 degrees apart. That is, on opposite sides of the frustum using WR 340 wave guides with bottom edge flush with the big base. Phase is adjusted to place sources 3 wavelengths apart.
Gaussian noise bandwidth at 0.05 * 2.47GHz is is double the expected magnetron noise bandwidth.

This is a debug run at resolution = 200, hence it may appear more granular than the resolution = 250 runs commonly uploaded. There are no csv files, resolution of 200 would adversely affect any data comparison calculations based on the csv files.

Great to see you got the waveguide injection working aero.

It looks like you placed the wave right on the bottom to replace the antennas,

If you look at the mode generation in the attached image...
You'll see close to the middle of the frustum is where the mode wants to generate within the frustum. Did you try to do the waveguides insertion at that point? We should try.

Shell

Move the waveguides up to the point where they are not inserting into the frustum which should be halfway up. See image.

Just to be clear on this point, the wave guides do not insert into the frustum. They are placed then cut cleanly at the inside surface of the frustum. The image shows that cut in the frustum cone as projected in the 2-D image of the 3-D object.  Not sure how you would actually construct them that way, but it is quite easy to model.

As currently modelled the wave guides are offset in z from the frustum exact center by -3.852 mm toward the big base. That aligns the bottom inside surface of the WR 340 with the inside surface of the big base. I will change that offset to zero from the frustum center and see what happens.
Not quite zero aero, we are dealing in the Z direction with different issues in mode generation because of the asymmetry of the frustum. I'll need to search to find the equation Dr. Rodel used in determining the percentages. Search is hideous btw. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/17/2015 06:48 PM

What is the relevance of resonating at an arbitrary mode shape like TE013?  (Why would one choose TE013 instead of other mode shapes) ?  ???

What theory supports the choice of TE013?  What is special about TE013? ???


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427162#msg1427162">Quote from: CraigPichach on 09/17/2015 04:34 PM</a>
Dr. Rodal, you lost me there. I thought that the EM-Drive/Q-Thruster phenomena was linked to the concept that the frustrum had to be at the exact resonance mode (i.e. a frustrum at TE013 at 900MHz would NOT be at TE013 at 2.45GHz and thus would NOT have the same thrust??). Is not a concern  in these experiments the question of how exact do you have to be to achieve resonance mode as oppose to simply resonating (to fluidize the quantum vacuum or whatever)?? Indeed with our ANSYS modelling we are finding that the cavity part itself is not so hard, but we've found it to be non-trivial in the way the rf needs to be launched into the cavity.... more complicated is the fact that we want to be able to try firing RF into the large side and be able to switch to the smaller side... though I guess the easiest choice is into the side.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426228#msg1426228">Quote from: Rodal on 09/14/2015 10:59 PM</a>

On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 09/17/2015 07:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427114#msg1427114">Quote from: rfmwguy on 09/17/2015 02:37 PM</a>
As a backup to the digital meter made for the LDS, I am using a basic, 10-bit A/D converter. Here it is:

http://www.dataq.com/products/di-145/

This is a USB interface and easy to use. It measures up to +/- 10 VDC and the LDS is about +/- 5 VDC. It will datalog and can provide a simple graphic display on vertical displacement at a sample rate of about 4 msec (240 Hz).
...

Great to hear about the 10-bit ADC DAQ! 

I took the liberty to examine their datasheet, and I suspect the DI-145 analog inputs do not contain much low-pass filtering.  I mention this as it can have a non-trivial impact on what ADC value gets generated for a given input (i.e. can get "noisy" digital output if there are frequencies greater than 120Hz in the real analog signal). 

Adding a simple low-pass filter might not be a bad idea to help eliminate any aliasing noise and help guard against unknown setup/hold requirements of the ADC channel (i.e. set filter to a ~120 Hz cutoff).  Also worth keeping in mind the 240Hz sampling rate is only valid for 1 analog channel;  if there are additional analog channels, the 240Hz gets subdivided accordingly (i.e. 1 ch@240Hz, 2 ch@120Hz, 3 ch @ 80Hz, etc) so any pre-filter would also need to be adjusted.

As a primer for other lurkers, a key principal in DSP (Digital Signal Processing) is known as the Nyquist Sampling Theorem. 

  https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem (https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem)

The basic summary is that when converting analog into digital, you can generally only reconstruct the original analog signal if the digital signal is sampled at a rate at least twice as fast as the highest frequency in the original analog signal.  Without the 2x sampling rate (digital sample vs analog freq), the digital signal won't contain all of the information from the original analog signal;  worse yet, the higher frequency information can "alias" and masquerade as a lower frequency signal in the digital output (see attached picture from Wikipedia).  Since the DI-145 claims a 240Hz sampling rate, any frequency greater than 120Hz in the analog signal can result in aliasing.  Pre-filtering the analog signal to eliminate the higher frequency content (i.e. >120Hz) will help avoid any alias-induced noise (although filters inevitably introduce distortion that must be accounted for;  primarily a time-delay, but often also a small voltage drop due to losses in a passive filter circuit).

Thanks,
James

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/17/2015 07:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427218#msg1427218">Quote from: jmossman on 09/17/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427114#msg1427114">Quote from: rfmwguy on 09/17/2015 02:37 PM</a>
As a backup to the digital meter made for the LDS, I am using a basic, 10-bit A/D converter. Here it is:

http://www.dataq.com/products/di-145/

This is a USB interface and easy to use. It measures up to +/- 10 VDC and the LDS is about +/- 5 VDC. It will datalog and can provide a simple graphic display on vertical displacement at a sample rate of about 4 msec (240 Hz).
...

Great to hear about the 10-bit ADC DAQ! 

I took the liberty to examine their datasheet, and I suspect the DI-145 analog inputs do not contain much low-pass filtering.  I mention this as it can have a non-trivial impact on what ADC value gets generated for a given input (i.e. can get "noisy" digital output if there are frequencies greater than 120Hz in the real analog signal). 

Adding a simple low-pass filter might not be a bad idea to help eliminate any aliasing noise and help guard against unknown setup/hold requirements of the ADC channel (i.e. set filter to a ~120 Hz cutoff).  Also worth keeping in mind the 240Hz sampling rate is only valid for 1 analog channel;  if there are additional analog channels, the 240Hz gets divided accordingly (i.e. 1 ch@240Hz, 2 ch@120Hz, 3 ch @ 80Hz, etc) so any pre-filter would also need to be adjusted.

As a quick primer for other lurkers, a key principal in DSP (Digital Signal Processing) is known as the Nyquist Sampling Theorem. 

  https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem (https://en.wikipedia.org/wiki/Nyquist%E2%80%93Shannon_sampling_theorem)

The quick summary is that when converting analog into digital, you can only faithfully reconstruct the original analog signal if the digital signal is sampled at a rate at least twice as fast as the highest frequency in the original analog signal.  Without the 2x sampling rate (digital sample vs analog freq), the digital signal won't contain all of the information from the original analog signal;  worse yet, the higher frequency information can "alias" and masquerade as a lower frequency signal in the digital output.  Since the DI-145 claims a 240Hz sampling rate, any frequency greater than 120Hz in the analog signal can result in aliasing.  Pre-filtering the analog signal to eliminate the higher frequency content (i.e. >120Hz) will help avoid any alias-induced noise (although filters inevitably introduce distortion that must be accounted for;  primarily a time-delay, but often also a small voltage drop due to losses in a passive filter circuit).

Thanks,
James
Very nice summary! The LDS has a pre-filtered amp. The entire assembly is an Omron Z4M-W40 plus an Omron K3NX display. Here's a datasheet: http://www.limasoft.cz/omron/pdf/z4m.pdf

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/17/2015 07:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427208#msg1427208">Quote from: Rodal on 09/17/2015 06:48 PM</a>
What is the relevance of resonating at an arbitrary mode shape like TE013?  (Why would one choose TE013 instead of other mode shapes) ?  ???

What theory supports the choice of TE013?  What is special about TE013? ???


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427162#msg1427162">Quote from: CraigPichach on 09/17/2015 04:34 PM</a>
Dr. Rodal, you lost me there. I thought that the EM-Drive/Q-Thruster phenomena was linked to the concept that the frustrum had to be at the exact resonance mode (i.e. a frustrum at TE013 at 900MHz would NOT be at TE013 at 2.45GHz and thus would NOT have the same thrust??). Is not a concern  in these experiments the question of how exact do you have to be to achieve resonance mode as oppose to simply resonating (to fluidize the quantum vacuum or whatever)?? Indeed with our ANSYS modelling we are finding that the cavity part itself is not so hard, but we've found it to be non-trivial in the way the rf needs to be launched into the cavity.... more complicated is the fact that we want to be able to try firing RF into the large side and be able to switch to the smaller side... though I guess the easiest choice is into the side.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426228#msg1426228">Quote from: Rodal on 09/14/2015 10:59 PM</a>

On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other.
@Rodal
I agree with you for higher performance of TE modes instead TM as you pointed out some times ago.
But what do you mean with "the higher the frequency the closer to each other"?
If you use dimensions 10 times smaller the total frequency difference between the modes is 10 times bigger ???

Example(random dimensions):
Dimensions bD=234mm sD=123mm Length=123mm
TE011=2,4543258071GHz
 TE013=4,2396819866GHz

Dimensions bD=23.4mm sD=12.3mm Length=12.3mm
TE011= 24,5432580708GHz
TE013=42.3968198663GHz

And @All:
- The higher the mode the more sensitive it is against variation of the dimensions.
+The higher the mode the lower the BW (in particular in relation to the "p" value of J'mnp).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/17/2015 08:24 PM

The statement <<and the higher the frequency the closer to each other >>, implies changing the excitation frequency under the condition of leaving everything else the same. That means,: same materials, same geometry, same boundary conditions, etc.  If you change any of the parameters affecting the frequency (you are arbitrarily changing the dimensions in your example below) then not much can be said without knowing in advance the (in this case arbitrary geometrical) change you intend to make.  The statement was made in the context of the experiment being discussed in the post that I was answering, in which it was implied that the geometry, materials, etc., remained the same and the only thing being changed was the excitation frequency.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427231#msg1427231">Quote from: X_RaY on 09/17/2015 07:55 PM</a>
...
But what do you mean with "the higher the frequency the closer to each other"?
If you use dimensions 10 times smaller the total frequency difference between the modes is 10 times bigger ???

Example(random dimensions):
Dimensions bD=234mm sD=123mm Length=123mm
TE011=2,4543258071GHz
 TE013=4,2396819866GHz

Dimensions bD=23.4mm sD=12.3mm Length=12.3mm
TE011= 24,5432580708GHz
TE013=42.3968198663GHz

And @All:
- The higher the mode the more sensitive it is against variation of the dimensions.
+The higher the mode(p value) the lower the BW.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/17/2015 08:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427240#msg1427240">Quote from: Rodal on 09/17/2015 08:24 PM</a>
The statement <<and the higher the frequency the closer to each other >>, obviously implies changing the excitation frequency and leaving everything else the same. That means,: same materials, same geometry, same boundary conditions, etc.  Obviously, if you change any of the parameters affecting the frequency (you are arbitrarily changing the dimensions in your example below) then nothing can be said without knowing the arbitrary geometrical change you intend to make.  The statement was made in the context of the experiment being discussed in the post that I was answering, in which it was implied that the geometry, materials, etc., remained the same and the only thing being changed was the excitation frequency.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427231#msg1427231">Quote from: X_RaY on 09/17/2015 07:55 PM</a>
...
But what do you mean with "the higher the frequency the closer to each other"?
If you use dimensions 10 times smaller the total frequency difference between the modes is 10 times bigger ???

Example(random dimensions):
Dimensions bD=234mm sD=123mm Length=123mm
TE011=2,4543258071GHz
 TE013=4,2396819866GHz

Dimensions bD=23.4mm sD=12.3mm Length=12.3mm
TE011= 24,5432580708GHz
TE013=42.3968198663GHz

And @All:
- The higher the mode the more sensitive it is against variation of the dimensions.
+The higher the mode(p value) the lower the BW.
Agreed. Also for the post before "What is special about TE013? ???"
:)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/17/2015 08:48 PM
Tangent - First Orion Spacecraft Manned Flight?

2023...8 years from now.

Almost as long as it took us to start the space program and land a man on the moon.

Sometimes I wonder.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/17/2015 09:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427203#msg1427203">Quote from: SeeShells on 09/17/2015 06:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427178#msg1427178">Quote from: aero on 09/17/2015 05:09 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427041#msg1427041">Quote from: SeeShells on 09/17/2015 06:50 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427035#msg1427035">Quote from: aero on 09/17/2015 05:53 AM</a>
@SeeShells,

Here are some views of the CE3 model. They are very preliminary but ... well, its as far as I have gotten.

https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23td2ZDeDFUUFdvLUk&usp=sharing)

It resonates but it's not a mode that I recognize.

Specifics-
Cavity is the SeeShell Crazy Eddie 2, upgraded by replacing the loop antenna with wave guides, hence CE3 model.
Drive frequency 2.47 GHz, Harminv calculated resonant frequency 2.47837658E+009 Hz, Q is good: ~ 1 million.
Antenna - dual magnetron wave guides, 180 degrees apart. That is, on opposite sides of the frustum using WR 340 wave guides with bottom edge flush with the big base. Phase is adjusted to place sources 3 wavelengths apart.
Gaussian noise bandwidth at 0.05 * 2.47GHz is is double the expected magnetron noise bandwidth.

This is a debug run at resolution = 200, hence it may appear more granular than the resolution = 250 runs commonly uploaded. There are no csv files, resolution of 200 would adversely affect any data comparison calculations based on the csv files.

Great to see you got the waveguide injection working aero.

It looks like you placed the wave right on the bottom to replace the antennas,

If you look at the mode generation in the attached image...
You'll see close to the middle of the frustum is where the mode wants to generate within the frustum. Did you try to do the waveguides insertion at that point? We should try.

Shell

Move the waveguides up to the point where they are not inserting into the frustum which should be halfway up. See image.

Just to be clear on this point, the wave guides do not insert into the frustum. They are placed then cut cleanly at the inside surface of the frustum. The image shows that cut in the frustum cone as projected in the 2-D image of the 3-D object.  Not sure how you would actually construct them that way, but it is quite easy to model.

As currently modelled the wave guides are offset in z from the frustum exact center by -3.852 mm toward the big base. That aligns the bottom inside surface of the WR 340 with the inside surface of the big base. I will change that offset to zero from the frustum center and see what happens.
Not quite zero aero, we are dealing in the Z direction with different issues in mode generation because of the asymmetry of the frustum. I'll need to search to find the equation Dr. Rodel used in determining the percentages. Search is hideous btw.

Well, we have 3.82 mm to work with. That is almost zero by itself, though it is nearly 1/2 the wave guide height. Frustum is 16.34 mm high, wave guide is 8.636 mm high. That means the lowest (toward the big end) the wave guide can go is 3.82 mm center to center.

I did complete the resonance run with Gaussian noise bandwidth = 0.025 * 2.47 GHz for both cases. With the wave guide aligned with the big end of the frustum, Harminv calculated a Q number in the 10's of millions. With the wave guide centered on the frustum, Harminv calculated a Q number in the 100's of thousands. (Remember, these numbers only indicate relative quality, not absolute quality) I am currently running Harminv with the wave guide moved half the distance to the Big end. That is split the difference between zero and max. We will see.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/17/2015 09:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427244#msg1427244">Quote from: X_RaY on 09/17/2015 08:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427240#msg1427240">Quote from: Rodal on 09/17/2015 08:24 PM</a>
The statement <<and the higher the frequency the closer to each other >>, obviously implies changing the excitation frequency and leaving everything else the same. That means,: same materials, same geometry, same boundary conditions, etc.  Obviously, if you change any of the parameters affecting the frequency (you are arbitrarily changing the dimensions in your example below) then nothing can be said without knowing the arbitrary geometrical change you intend to make.  The statement was made in the context of the experiment being discussed in the post that I was answering, in which it was implied that the geometry, materials, etc., remained the same and the only thing being changed was the excitation frequency.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427231#msg1427231">Quote from: X_RaY on 09/17/2015 07:55 PM</a>
...
But what do you mean with "the higher the frequency the closer to each other"?
If you use dimensions 10 times smaller the total frequency difference between the modes is 10 times bigger ???

Example(random dimensions):
Dimensions bD=234mm sD=123mm Length=123mm
TE011=2,4543258071GHz
 TE013=4,2396819866GHz

Dimensions bD=23.4mm sD=12.3mm Length=12.3mm
TE011= 24,5432580708GHz
TE013=42.3968198663GHz

And @All:
- The higher the mode the more sensitive it is against variation of the dimensions.
+The higher the mode(p value) the lower the BW.
Agreed. Also for the post before "What is special about TE013? ???"
:)
I know that the mode TE011 and TE013 have the same EMF cross sections and I could have done TE011 or a TE013 which I seriously looked at, but the ceramic plate sizes I had available TE012 was easier for me to do. Also a TE012 mode was the goal with RS in the EMDrive he made for Boeing and also a goal for EW when they were trying to get thrust. It was an obvious choice with the materials I could get.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cuddihy on 09/17/2015 11:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427247#msg1427247">Quote from: rfmwguy on 09/17/2015 08:48 PM</a>
Tangent - First Orion Spacecraft Manned Flight?

2023...8 years from now.

Almost as long as it took us to start the space program and land a man on the moon.

Sometimes I wonder.
No bucks, no buck rogers.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/17/2015 11:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427298#msg1427298">Quote from: cuddihy on 09/17/2015 11:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427247#msg1427247">Quote from: rfmwguy on 09/17/2015 08:48 PM</a>
Tangent - First Orion Spacecraft Manned Flight?

2023...8 years from now.

Almost as long as it took us to start the space program and land a man on the moon.

Sometimes I wonder.
No bucks, no buck rogers.
Good thought, although if you look closely, there is a large budget still available. Not being an insider, it appears a lot of it is earmarked for climate observations, PR and aeronautical applications. If I recall the 60s correctly (OK, so I was a kid), it seemed like NASA went aeronautical in order to advance to space. We have done this already.

The way I read it now is LEO is the domain of the ISS and getting up there is being farmed-out. Perhaps thats the natural progression of things, but I'd like to see more focus on advanced spaceflight, manned or unmanned.

Wouldn't it be the ultimate defeat if humanity is destined to be stuck on this rock forever; I guess is my long-term concern...of course, once my time is up, I won't care ;^)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/18/2015 12:44 AM
@SeeShells

Here are 3 data points showing Q variation with wave guide offset from the center of the frustum toward the big end. Q is plotted as log10 values and z values are in millimeters.

Note that the model has the central axis of the wave guide parallel to the plane of the frustum bases, not perpendicular to the conic side wall. Is that an issue?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/18/2015 01:46 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427310#msg1427310">Quote from: aero on 09/18/2015 12:44 AM</a>
@SeeShells

Here are 3 data points showing Q variation with wave guide offset from the center of the frustum toward the big end. Q is plotted as log10 values and z values are in millimeters.

Note that the model has the central axis of the wave guide parallel to the plane of the frustum bases, not perpendicular to the conic side wall. Is that an issue?
The waveguide you laid out is a rectangular guide and I hope following the WR340 sizing. The central axis or longer axis of the waveguide should be along the Z axis centered to the Z center-line.
Not at a angle like the Dresden run but the waveguide should be parallel to the top and bottom plate. They got the orientation correct.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/18/2015 04:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427318#msg1427318">Quote from: SeeShells on 09/18/2015 01:46 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427310#msg1427310">Quote from: aero on 09/18/2015 12:44 AM</a>
@SeeShells

Here are 3 data points showing Q variation with wave guide offset from the center of the frustum toward the big end. Q is plotted as log10 values and z values are in millimeters.

Note that the model has the central axis of the wave guide parallel to the plane of the frustum bases, not perpendicular to the conic side wall. Is that an issue?
The waveguide you laid out is a rectangular guide and I hope following the WR340 sizing. The central axis or longer axis of the waveguide should be along the Z axis centered to the Z center-line.
Not at a angle like the Dresden run but the waveguide should be parallel to the top and bottom plate. They got the orientation correct.

I believe I have it right then. Here:
(define wg-hi 0.08636)                         ; frustum z dimension               ;  WR 340 wave guide
(define wg-wd 0.04318)                       ; frustum x dimension                 ;  inner dimensions 
(define wg-lg (- 0.1213734648 0.042))   ; frustum y dimension.

Your coordinate reference is a little confusing, but I understand you to be using z as the classic reference to the central axis of the wave guide. Meep coordinates are defined WRT the frustum.

The defined meep coordinate system uses z as the axis of rotation of the frustum with the central axis (long axis, or propagation direction of the travelling wave) of the wave guide aligned in the direction of the frustum y coordinate direction. The wave guide z coordinate is in the wide dimension. This leaves the x coordinate in the direction of the narrow width of the rectangular wave guide.

The model is very similar to the picture of Tajmar's set-up except for the angle between the axis of rotation of the frustum and the axis of propagation of the wave guide. I don't know what Tajmar had this angle at, but in the meep model it is 90 degrees exactly. The wave guide is parallel to the base planes of the frustum.

So answering my own question, this is not an issue, we are on the same page.

Now, do you want me to remove the back wave guide/source model and run it with only one wave guide/source exciting the frustum?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/18/2015 05:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427263#msg1427263">Quote from: SeeShells on 09/17/2015 09:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427244#msg1427244">Quote from: X_RaY on 09/17/2015 08:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427240#msg1427240">Quote from: Rodal on 09/17/2015 08:24 PM</a>
The statement <<and the higher the frequency the closer to each other >>, obviously implies changing the excitation frequency and leaving everything else the same. That means,: same materials, same geometry, same boundary conditions, etc.  Obviously, if you change any of the parameters affecting the frequency (you are arbitrarily changing the dimensions in your example below) then nothing can be said without knowing the arbitrary geometrical change you intend to make.  The statement was made in the context of the experiment being discussed in the post that I was answering, in which it was implied that the geometry, materials, etc., remained the same and the only thing being changed was the excitation frequency.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427231#msg1427231">Quote from: X_RaY on 09/17/2015 07:55 PM</a>
...
But what do you mean with "the higher the frequency the closer to each other"?
If you use dimensions 10 times smaller the total frequency difference between the modes is 10 times bigger ???

Example(random dimensions):
Dimensions bD=234mm sD=123mm Length=123mm
TE011=2,4543258071GHz
 TE013=4,2396819866GHz

Dimensions bD=23.4mm sD=12.3mm Length=12.3mm
TE011= 24,5432580708GHz
TE013=42.3968198663GHz

And @All:
- The higher the mode the more sensitive it is against variation of the dimensions.
+The higher the mode(p value) the lower the BW.
Agreed. Also for the post before "What is special about TE013? ???"
:)
I know that the mode TE011 and TE013 have the same EMF cross sections and I could have done TE011 or a TE013 which I seriously looked at, but the ceramic plate sizes I had available TE012 was easier for me to do. Also a TE012 mode was the goal with RS in the EMDrive he made for Boeing and also a goal for EW when they were trying to get thrust. It was an obvious choice with the materials I could get.

Shell

It was RS who told me SPR now use TE013 for their work. He encouraged me to design for TE103. As I understand it, the spherical end plate, narrow Rf bandwidth based Boeing Flight Thruster was a TE013 design.

All the SC EMDrive stuff produced by RS since the Flight Thruster, uses Rf injection in the middle of the frustum side wall, which would inject the Rf into the middle lode of the 3 lobes of the TE013 mode. Also means at that injection point, it is the same / equal guide wavelength to/from both end plates.

I suspect doing it this way would reduce phase distortion from the Rf injection, on the already resonant standing wave, and increase the effective antenna coupling factor, lifting the loaded / operational Q value toward the max unloaded Q value.

Doing the Rf injection bursts of 20% of 1 TC would allow the post Rf injection resonant standing wave to form without injection induced phase distortion and lift post injection Force generation from the resultant higher Q. It may be that the low cost magnetrons use of pulsed 1/2 wave DC may induce this condition at the end of each 1/2 cycle of Rf energy being injected. Additionally the naturally pulsed magnetron output may again trigger multiple of this post no excitation increased Force generation event during each 1/2 on cycle.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/18/2015 07:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427147#msg1427147">Quote from: wallofwolfstreet on 09/17/2015 04:17 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427021#msg1427021">Quote from: ThinkerX on 09/17/2015 02:58 AM</a>
Hmm...

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1426910#msg1426910">Quote from: X_RaY on 09/16/2015 08:18 PM</a>
I found a nice youtube channel, sure that's already known, nevertheless quite interesting to see the pure mechanically conditions in such a simulation  ;D

https://www.youtube.com/watch?v=MxhT5_Hh2CA
some more vids are available

1 - One of my first posts here (way back in thread one) dealt with this - that the EM Drive moved on account of its shape.

2 - I was told the concept violated the laws of thermodynamics.  So, given that, are these simulations legit?

Ok, thought experiment.  Say we use actual physical objects instead of photons.  maybe old fashioned 'super balls' or something similar, though unlike photons they would slow down.  A frustum in a zero G environment.  Would the results match the simulation?

To answer your question:
Quote
So, given that, are these simulations legit?

No, these simulations are not legit.  A frustum in a zero G environment would not have results that match the simulation.

Exactly what when wrong in the simulation, I couldn't say without seeing everything he did to the settings, etc.  But the results are completely nonphysical and don't correspond to the real world.

Just intuitively, a bunch of non-zero momentum particles bouncing around in an asymetric cavity isn't a rare system.  Such systems exist everywhere.  Even the most energetic photons have negligible momentum if we compare them to your average gas particle at STP.  So if this simulation was legitimate (which it isn't), then a coke bottle filled with air or your average household balloon ought to be rocketing around with orders of magnitude better thrust than an emdrive.

I'm not going to take the time to flesh out the solution to such a problem mathematically, but it isn't difficult.  The case of infinitely many particles is equivalent to the uniform pressure case, and a person only needs some trig to be able to solve it.  In fact, the intuition of the problem is simple and shows the issue with what the youtube poster believes is happening.

In the video, he says that because the walls of the cone are angled off the plane of the horizontally flat base, only some of the force they experience when struck by a particle is in the vertical direction.  This is correct, but it does not lead to any net movement in the vertical direction because the angled walls also have a greater area than the horizontal base.  While one bounce against the flat base creates a greater vertical force than a bounce off the angled side walls, the fact that there is greater chance to hit a side wall than there is the top base due to the greater area perfectly cancels, so there is no net force over time.

If that wasn't enough, also realize that the simulation showed the drive moving towards the direction of the "big" base, which is opposite the direction the emdrive is supposed to go.

So if anything, these simulations are a case study in how you need to have a proper understanding of first principles to tell whether or not your simulations are correct.   
I can support wallofwolfstreet's comment that these so called "simulations" do not represent a real physics process.

Professionally, I'm using a similar 3D program with an almost identical rigid & softbody dynamics module.
The confusing originates from the arbitrary use of the word "simulation".

There is a distinct difference between an animation and a simulation:

An animation is designed with a certain intend. Their dynamics module is not designed for physical accuracy, but for efficiency and speed, consequently, these processes are hugely simplified.
From the outside they do appear to be simulations, but in reality , they're not...

A simulation uses genuine physics data and formulas in an attempt to replicate real events. It has no intend. There are software packages that are capable of simulating real natural events (fluid dynamics, nuclear explosion, etc) but these usually need a massive amount of computing power for days.

These 3D packages are all ANIMATION software packages, designed to make or support story telling.
Their dynamic modules are designed to be near real time and do cut a lot of corners to achieve that.

Sadly,  animations are often disguised and sold as "simulations", because those carry a lot more public credibility, because they're used in the scientific, industrial and military world.

Bottom line:
I would not base any scientific conclusion based on the dynamics engine you find in Maya, 3DStudio, Softimage, etc.
Their proper use of those software packages is to make wonderful renders of how the EMdrive spaceship IXS Clark would/could look like...To tell a story, to spark imagination....

not to simulate a difficult and complex physics problem...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Devilstower on 09/18/2015 10:18 AM

Quote rom @flyby
There is a distinct difference between an animation and a simulation:

An animation is designed with a certain intend. Their dynamics module is not designed for physical accuracy, but for efficiency and speed, consequently, these processes are hugely simplified.
From the outside they do appear to be simulations, but in reality , they're not...
Absolutely right. The focus of these applications is to provide the appearance of real materials, not to simulate them on every level. Depending on the strength of the program, simple properties like density can be well represented, but even properties that affect physical transformation — say, something like ductility — may be poor to nonexistent. 

There's just enough in the best animation systems to fool you into believing they model reality, and not a penny more. I've yet to run into one that could adequately model the behavior of simple projectiles in air, much less an EM drive.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/18/2015 12:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427340#msg1427340">Quote from: TheTraveller on 09/18/2015 05:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427263#msg1427263">Quote from: SeeShells on 09/17/2015 09:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427244#msg1427244">Quote from: X_RaY on 09/17/2015 08:31 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427240#msg1427240">Quote from: Rodal on 09/17/2015 08:24 PM</a>
The statement <<and the higher the frequency the closer to each other >>, obviously implies changing the excitation frequency and leaving everything else the same. That means,: same materials, same geometry, same boundary conditions, etc.  Obviously, if you change any of the parameters affecting the frequency (you are arbitrarily changing the dimensions in your example below) then nothing can be said without knowing the arbitrary geometrical change you intend to make.  The statement was made in the context of the experiment being discussed in the post that I was answering, in which it was implied that the geometry, materials, etc., remained the same and the only thing being changed was the excitation frequency.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427231#msg1427231">Quote from: X_RaY on 09/17/2015 07:55 PM</a>
...
But what do you mean with "the higher the frequency the closer to each other"?
If you use dimensions 10 times smaller the total frequency difference between the modes is 10 times bigger ???

Example(random dimensions):
Dimensions bD=234mm sD=123mm Length=123mm
TE011=2,4543258071GHz
 TE013=4,2396819866GHz

Dimensions bD=23.4mm sD=12.3mm Length=12.3mm
TE011= 24,5432580708GHz
TE013=42.3968198663GHz

And @All:
- The higher the mode the more sensitive it is against variation of the dimensions.
+The higher the mode(p value) the lower the BW.
Agreed. Also for the post before "What is special about TE013? ???"
:)
I know that the mode TE011 and TE013 have the same EMF cross sections and I could have done TE011 or a TE013 which I seriously looked at, but the ceramic plate sizes I had available TE012 was easier for me to do. Also a TE012 mode was the goal with RS in the EMDrive he made for Boeing and also a goal for EW when they were trying to get thrust. It was an obvious choice with the materials I could get.

Shell

It was RS who told me SPR now use TE013 for their work. He encouraged me to design for TE103. As I understand it, the spherical end plate, narrow Rf bandwidth based Boeing Flight Thruster was a TE013 design.

All the SC EMDrive stuff produced by RS since the Flight Thruster, uses Rf injection in the middle of the frustum side wall, which would inject the Rf into the middle lode of the 3 lobes of the TE013 mode. Also means at that injection point, it is the same / equal guide wavelength to/from both end plates.

I suspect doing it this way would reduce phase distortion from the Rf injection, on the already resonant standing wave, and increase the effective antenna coupling factor, lifting the loaded / operational Q value toward the max unloaded Q value.

Doing the Rf injection bursts of 20% of 1 TC would allow the post Rf injection resonant standing wave to form without injection induced phase distortion and lift post injection Force generation from the resultant higher Q. It may be that the low cost magnetrons use of pulsed 1/2 wave DC may induce this condition at the end of each 1/2 cycle of Rf energy being injected. Additionally the naturally pulsed magnetron output may again trigger multiple of this post no excitation increased Force generation event during each 1/2 on cycle.

After testing 2 magnetrons and power supplies with a 50% duty cycle and watching the outputs produce a very jittery RF envelope, I felt it was prudent to try to stabilize the output by controlling the heater and turning the power supply into a 100% duty cycle. Off the shelf power supplies aren't rated for that type of operation and whether it was the output transformer saturating or sub-standard HV caps and diodes they both failed. I even lowered the input voltage to reduce the demands on the power supply and it still failed.

Because of this inability to be stable and wasting a lot of power in off resonate frequency bands as it jitters around and not being able to stabilize the output I went to a Inverter driven power supply. I'm setting up the breadboard getting ready to test and should be able to get some good data next week.

Resonate standing wave distortion occurs from injecting into a asymmetrical cavity. You can do sidewall injection like RS but you're still going to see distortion as the wave reflects from the opposite wall of the frustum interacting out of phase with the incoming wave fronts. You can try to avoid this by symmetrically injecting from the end plates, or try to use a symmetric dual injector scheme.

Considering the different power supplies and non magnetron injection test beds that have made thrust, it seems to be prudent to let the frustum do what the frustum does. That is the creation of a reasonable and stable mode by a symmetrical and stable RF input, as the frustum will degrade it from it's very shape.

This has been my goal for sometime and with the help of so many here narrowed it down to two paths. Inject in the small top reflector with multiple modified loop antennas forcing a stable TE012 and followed up by a symmetrical waveguide injection. Both schemes will use the stabilized inverter power supply.

Shell

PS: Was asked about a load for testing the magnetron in and I settled on simply using the microwave oven. Works quite well btw.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/18/2015 04:24 PM

Dr. Rodal, concern wasn't what mode (TE013 was picked at random as discussed below), but why you would think the mode is irrelevant so long as the cavity is resonating per your comment:

"On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other."

You seem to imply that if you have a cavity sized for say for 900MHz at TE013 (or whatever mode you think is optimal for thrust) that at 2.45GHz it is resonating anyway and thus should see the same thrust generation leading one to believe that mode is irrelevant (which I thought was not the case, indeed have you not worked out an exact solution for calculating dimensions for mode @ frequency?).

Are not researchers such as NASA Eagleworks trying to excite resonance modes as opposed to simply induce resonance. TE013 was an example. Clearly a frustrum with dimensions sized for TE013 at 900MHz would NOT be at TE013 at 2.45GHz... just as a TM014 (or TE012, or whatever mode your choose) frustrum with dimensions sized for 900MHz would NOT be at TM014 (or TE012, or whatever mode your choose) at 2.45GHz.

The importance of the question is clear in that if mode is irrelevant than why would researchers bother calculating the modes and trying to target modes with respect to thrust generation??

Based on all the talk of modes if the Q-Thruster/EM-Drive I thought researchers are linking thrust generation with reaching target modes, not asking is mode relevant but what is the optimum resonance mode and questions as to why mode matters as opposed to "who cares about mode as long as your resonating?"

Examples are evident in the research publications

 "Using finite element numerical method to numerical analyse the classical Maxwell equation of electric field of the idealised conical resonator, to obtain the model and practical of the distribution of the electric field of the cavity under 1000W. By analyse the properties under different modes and the different properties. Calculation show that under the four modes, TE011, TE012, TE111 and TM011, the quality factor of TE012 is highest and with highest thrust, followed by TE011. - Chinese Paper

NASA was targeting with the "proposed" 100kW thruster I think TM010 which I assume is the optimal mode they are targeting (i.e. 100kW with a 9in H, 6.25in Small D, 11.01 in Large D unit at 957Hz seems to be sized for TM010)?

Choice of TE013 was arbitrary as in another forum I am asking the question of at 930MHz why we would want to size the frustrum for TE013 vs. TE012 vs the TM010 picked by NASA. That's the real question in my mind, why one mode over another, not - "frustrum is resonating, so should see thrust regardless of mode" as implied that a frustrum designed for a mode at 900MHz should see thrust at 2.45GHz simply because its resonating.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427208#msg1427208">Quote from: Rodal on 09/17/2015 06:48 PM</a>
What is the relevance of resonating at an arbitrary mode shape like TE013?  (Why would one choose TE013 instead of other mode shapes) ? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/18/2015 04:36 PM

TE013 or TE103?

I guess our modelling is showing that it is difficult to put in the RF from the waveguide launcher into the top or bottom and they too want to put it in the side and mentioned TE013 (and ironically this was for a pulsed test).

Anyone think that TE013 would be optimum for "thrust generation" reasons (though I suppose better Q-factor is reason enough?)?


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427340#msg1427340">Quote from: TheTraveller on 09/18/2015 05:36 AM</a>

It was RS who told me SPR now use TE013 for their work. He encouraged me to design for TE103. As I understand it, the spherical end plate, narrow Rf bandwidth based Boeing Flight Thruster was a TE013 design.

All the SC EMDrive stuff produced by RS since the Flight Thruster, uses Rf injection in the middle of the frustum side wall, which would inject the Rf into the middle lode of the 3 lobes of the TE013 mode. Also means at that injection point, it is the same / equal guide wavelength to/from both end plates.

I suspect doing it this way would reduce phase distortion from the Rf injection, on the already resonant standing wave, and increase the effective antenna coupling factor, lifting the loaded / operational Q value toward the max unloaded Q value.

Doing the Rf injection bursts of 20% of 1 TC would allow the post Rf injection resonant standing wave to form without injection induced phase distortion and lift post injection Force generation from the resultant higher Q. It may be that the low cost magnetrons use of pulsed 1/2 wave DC may induce this condition at the end of each 1/2 cycle of Rf energy being injected. Additionally the naturally pulsed magnetron output may again trigger multiple of this post no excitation increased Force generation event during each 1/2 on cycle.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/18/2015 04:47 PM

Mr. Pichach,  the literature points out that there is NO particular mode shape that is predicted to provide more thrust.  On the contrary:



1) NASA Eagleworks is the only testing organization that has actually experimentally verified the mode shape that they excited: it was TM212, which is not even a TE mode.  Nobody else has experimentally verified what mode shape was excited.  Talk about mode shapes by others (except NASA Eagleworks) is just that: talk, and it cannot be scientifically accepted as corroboration of a any mode shape, particularly when Finite Element and exact solution analysis shows that there are several mode shapes in the frequency range of testing.

2) Neither R. Shawyer nor Prof.. Yang ever conducted a single test in a partial vacuum.  Their test claims have NOT been replicated by any scientific organization whatsoever.  If anything, the tests at TU Dresden and at NASA Eagleworks (resulting in thrust force/InputPower that are orders of magnitude smaller than the claims of Shawyer and Yang) have served as a scientific refutation of the claims by Shawyer and Yang, that one must objectively (in light of experiemental attempts at replication) to be subject to the well known "gas effect" (thermal convection, etc.) that has been known to plague all experimental measurements of electromagnetic pressure ever since it was predicted by Maxwell.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427426#msg1427426">Quote from: CraigPichach on 09/18/2015 04:24 PM</a>
Dr. Rodal, concern wasn't what mode (TE013 was picked at random as discussed below), but why you would think the mode is irrelevant so long as the cavity is resonating per your comment:

"On the contrary, if a cavity of given dimensions resonates at a lower frequency, it will certainly also resonate at higher frequencies, and the higher the frequency the closer to each other (on a % basis) are the natural frequencies to each other."

You seem to imply that if you have a cavity sized for say for 900MHz at TE013 (or whatever mode you think is optimal for thrust) that at 2.45GHz it is resonating anyway and thus should see the same thrust generation leading one to believe that mode is irrelevant (which I thought was not the case).

Are not researchers such as NASA Eagleworks trying to excite resonance modes as opposed to simply induce resonance. TE013 was an example. Clearly a frustrum with dimensions sized for TE013 at 900MHz would NOT be at TE013 at 2.45GHz... just as a TM014 (or TE012, or whatever mode your choose) frustrum with dimensions sized for 900MHz would NOT be at TM014 (or TE012, or whatever mode your choose) at 2.45GHz.

The importance of the question is clear in that if mode is irrelevant than why would researchers bother calculating the modes and trying to target modes with respect to thrust generation??

Based on all the talk of modes if the Q-Thruster/EM-Drive I thought researchers are linking thrust generation with reaching target modes, not asking is mode relevant but what is the optimum resonance mode and questions as to why mode matters as opposed to "who cares about mode as long as your resonating?"

Examples are evident in the research publications

 "Using finite element numerical method to numerical analyse the classical Maxwell equation of electric field of the idealised conical resonator, to obtain the model and practical of the distribution of the electric field of the cavity under 1000W. By analyse the properties under different modes and the different properties. Calculation show that under the four modes, TE011, TE012, TE111 and TM011, the quality factor of TE012 is highest and with highest thrust, followed by TE011. - Chinese Paper

NASA was targeting with the "proposed" 100kW thruster I think TM010 which I assume is the optimal mode they are targeting (i.e. 100kW with a 9in H, 6.25in Small D, 11.01 in Large D unit at 957Hz seems to be sized for TM010)?

Choice of TE013 was arbitrary as in another forum I am asking the question of at 930MHz why we would want to size the frustrum for TE013 vs. TE012 vs the TM010 picked by NASA. That's the real question in my mind, why one mode over another, not - "frustrum is resonating, so should see thrust regardless of mode" as implied that a frustrum designed for a mode at 900MHz should see thrust at 2.45GHz simply because its resonating.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427208#msg1427208">Quote from: Rodal on 09/17/2015 06:48 PM</a>
What is the relevance of resonating at an arbitrary mode shape like TE013?  (Why would one choose TE013 instead of other mode shapes) ? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/18/2015 04:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427430#msg1427430">Quote from: CraigPichach on 09/18/2015 04:36 PM</a>
TE013 or TE103?

I guess our modelling is showing that it is difficult to put in the RF from the waveguide launcher into the top or bottom and they too want to put it in the side and mentioned TE013 (and ironically this was for a pulsed test).

Anyone think that TE013 would be optimum for "thrust generation" reasons (though I suppose better Q-factor is reason enough?)?


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427340#msg1427340">Quote from: TheTraveller on 09/18/2015 05:36 AM</a>

It was RS who told me SPR now use TE013 for their work. He encouraged me to design for TE103. As I understand it, the spherical end plate, narrow Rf bandwidth based Boeing Flight Thruster was a TE013 design.

...

Does the TE 014 have a higher quality than TE 013?
[picture from Microwave Engineering by David Pozar 4th ed]

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/18/2015 05:00 PM
NSF-1701 update - Thanks to donations, I was able to afford an inexpensive thermal camera which I ordered today. Will be using it for magnetron and frustum viewing under power to try and understand heat sources. The larger than expected thermal lift characteristics while using mesh sidewalls has me a bit perplexed.

The magnetron and additional heatsink are above the frustum assembly and shouldn't be contributing to lift, unless its generating upwards air currents that "lift" the lower assembly upwards. I had expected cooler air to rush in at 90 degrees to the magnetron, not lifting it from underneath.

So...my focus will be on the cavity itself to see how fast and how much it heats up. I have not measured much thermal rise on the frustum (with a spot IR thermometer) once power is removed. A bit puzzling.

Thanks to all who are helping. $ as they come in are going directly to test gear. Happy wife...happy life.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/18/2015 05:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427439#msg1427439">Quote from: rfmwguy on 09/18/2015 05:00 PM</a>
NSF-1701 update - Thanks to donations, I was able to afford an inexpensive thermal camera which I ordered today. Will be using it for magnetron and frustum viewing under power to try and understand heat sources. The larger than expected thermal lift characteristics while using mesh sidewalls has me a bit perplexed.

The magnetron and additional heatsink are above the frustum assembly and shouldn't be contributing to lift, unless its generating upwards air currents that "lift" the lower assembly upwards. I had expected cooler air to rush in at 90 degrees to the magnetron, not lifting it from underneath.

So...my focus will be on the cavity itself to see how fast and how much it heats up. I have not measured much thermal rise on the frustum (with a spot IR thermometer) once power is removed. A bit puzzling.

Thanks to all who are helping. $ as they come in are going directly to test gear. Happy wife...happy life.

Can you use the thermal camera, as done by NASA Eagleworks to look into the flat ends and thereby verify what mode shape (if any) is being excited?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/18/2015 05:46 PM
Thought some might be interested it the attached image. You may recognize the 6 degree Yang-Shell model. I've posted similar images before but this one is different. It is the final fields at the end of a 2048 cycle run.

Still using Resolution = 250 and at the end of 2048 cycles, meep time is  t = 835.342 (417671 timesteps). Since meep time is about 1 ns, that gives a simulated run of nearly a microsecond. (Meep time = a/c and I use a=0.3 so meep time = 1.00069 ns)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/18/2015 06:55 PM
Just a thought on mode.  I think the EMDrive might be a form of reflected energy thruster.  (Similar to a photononic laser thruster).  Something massless and traveling at the speed of light is, somehow, exiting the drive and being reflected back for additional bounces.  Instead of a mirror we are using some kind of electromagnetic effect that reflects photons and is moving away from the drive opposite the direction of travel.

So that got me wondering, could there be some form of "ghost lobes" outside the drive that extend the resonance pattern we are seeing inside it.

This is probably better off on reddit than here, but here goes anyway:

Let me make a prediction about that Yang/Shell.  I bet that if you animate it, it would look like lobes form at the small baseplate, and exit the frustum at the large plate.  Let me also go out on a limb and suggest that a successful EMDrive will be one who's geometry causes causes the photons in the lobes (or at least some of them) to hit at greater than the critical angle to create an evanescent wave (that is tunneling out of the frustum), and then resonance (i.e. bouncing off the end plate) is somehow maintained on the other side of the plate
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/18/2015 07:26 PM

Dr. Rodal, the ramifications of your claim that mode shape does not impact potential thrust are huge in my opinion.

Why do you think the NASA Eagleworks experiment then saw thrust at one particular frequency for one particular dimension that happened to be a shape mode?

Do you still agree that you need to target one or certain frequencies for certain frustrum dimensions to see EM-Drive/Q-Thruster phenomena but it isn't a shape mode as we define it or are you saying that its just resonance or the effect simply doesn't exist at all so it all doesn't matter?

If we don't need to target shape modes, yet the "EM-Drive/Q-Thruster" phenomena only occurs at a particular frequency for a particular dimension than isn't it amazing we've managed to find anything at all? Indeed is not the logical experiment than to fire RF all across the spectrum for a dimension and see if, when and where we see thrust given all bets are off as to when we see something (and given anything seen was basically completely by chance?!?!?) i.e. Was Paul March wasting his time coming up with all those shape modes?

What happened to all the talk on "thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes."

Would you agree that this is a fundamental shift in even your original thinking - I mean why did you come up with an exact solution for shape modes then relating to Q-Thruster/EM-Drive?

(Side note - huge ramifications if resonance shape and just resonance explains "thrust" with respect to Eagleworks claims to magnetohydrodynamics and QV fluidization at work).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427431#msg1427431">Quote from: Rodal on 09/18/2015 04:47 PM</a>
Mr. Pichach,  the literature points out that there is NO particular mode shape that is predicted to provide more thrust.  On the contrary:



1) NASA Eagleworks is the only testing organization that has actually experimentally verified the mode shape that they excited: it was TM212, which is not even a TE mode.  Nobody else has experimentally verified what mode shape was excited.  Talk about mode shapes by others (except NASA Eagleworks) is just that: talk, and it cannot be scientifically accepted as corroboration of a any mode shape, particularly when Finite Element and exact solution analysis shows that there are several mode shapes in the frequency range of testing.

2) Neither R. Shawyer nor Prof.. Yang ever conducted a single test in a partial vacuum.  Their test claims have NOT been replicated by any scientific organization whatsoever.  If anything, the tests at TU Dresden and at NASA Eagleworks (resulting in thrust force/InputPower that are orders of magnitude smaller than the claims of Shawyer and Yang) have served as a scientific refutation of the claims by Shawyer and Yang, that one must objectively (in light of experiemental attempts at replication) to be subject to the well known "gas effect" (thermal convection, etc.) that has been known to plague all experimental measurements of electromagnetic pressure ever since it was predicted by Maxwell.



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/18/2015 07:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427440#msg1427440">Quote from: Rodal on 09/18/2015 05:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427439#msg1427439">Quote from: rfmwguy on 09/18/2015 05:00 PM</a>
NSF-1701 update - Thanks to donations, I was able to afford an inexpensive thermal camera which I ordered today. Will be using it for magnetron and frustum viewing under power to try and understand heat sources. The larger than expected thermal lift characteristics while using mesh sidewalls has me a bit perplexed.

The magnetron and additional heatsink are above the frustum assembly and shouldn't be contributing to lift, unless its generating upwards air currents that "lift" the lower assembly upwards. I had expected cooler air to rush in at 90 degrees to the magnetron, not lifting it from underneath.

So...my focus will be on the cavity itself to see how fast and how much it heats up. I have not measured much thermal rise on the frustum (with a spot IR thermometer) once power is removed. A bit puzzling.

Thanks to all who are helping. $ as they come in are going directly to test gear. Happy wife...happy life.

Can you use the thermal camera, as done by NASA Eagleworks to look into the flat ends and thereby verify what mode shape (if any) is being excited?
Sure can! No pun intended  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/18/2015 07:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427460#msg1427460">Quote from: SteveD on 09/18/2015 06:55 PM</a>
Just a thought on mode.  I think the EMDrive might be a form of reflected energy thruster.  (Similar to a photononic laser thruster).  Something massless and traveling at the speed of light is, somehow, exiting the drive and being reflected back for additional bounces.  Instead of a mirror we are using some kind of electromagnetic effect that reflects photons and is moving away from the drive opposite the direction of travel.

Well, there is the thought/claim that evanescent waves stay attached, looping outward and back, redepositing their energy.
Quote

So that got me wondering, could there be some form of "ghost lobes" outside the drive that extend the resonance pattern we are seeing inside it.

This is probably better off on reddit than here, but here goes anyway:

Let me make a prediction about that Yang/Shell.  I bet that if you animate it, it would look like lobes form at the small baseplate, and exit the frustum at the large plate.  Let me also go out on a limb and suggest that a successful EMDrive will be one who's geometry causes causes the photons in the lobes (or at least some of them) to hit at greater than the critical angle to create an evanescent wave, and then resonance (i.e. bouncing off the end plate) is somehow maintained on the other side of the plate

I've mentioned this idea before, but it needs some math backing to be taken seriously. I wonder if the evanescent photons escape the cavity by a tunnelling-like mechanism at superluminal velocity, then loop back to the cavity at light speed. It is only during the tunnelling process that the photons are superluminal carrying superluminal momentum (JMO).

That idea leaves open more than one idea for the thrust creation. It could be simply momentum variation of the evanescent photons, as I allude above, or perhaps the exchange of energy mass from the inside to outside results in a gravitational effect on the cavity.  But I am not competent to broach this subject mathematically.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/18/2015 07:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427470#msg1427470">Quote from: CraigPichach on 09/18/2015 07:26 PM</a>

If we don't need to target shape modes, yet the "EM-Drive/Q-Thruster" phenomena only occurs at a particular frequency for a particular dimension than isn't it amazing we've managed to find anything at all? Indeed is not the logical experiment than to fire RF all across the spectrum for a dimension and see if, when and where we see thrust given all bets are off as to when we see something (and given anything seen was basically completely by chance?!?!?)

Well, given the use of a noisy magnetron. . .

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/18/2015 07:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427473#msg1427473">Quote from: aero on 09/18/2015 07:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427460#msg1427460">Quote from: SteveD on 09/18/2015 06:55 PM</a>
Just a thought on mode.  I think the EMDrive might be a form of reflected energy thruster.  (Similar to a photononic laser thruster).  Something massless and traveling at the speed of light is, somehow, exiting the drive and being reflected back for additional bounces.  Instead of a mirror we are using some kind of electromagnetic effect that reflects photons and is moving away from the drive opposite the direction of travel.

Well, there is the thought/claim that evanescent waves stay attached, looping outward and back, redepositing their energy.
Quote

So that got me wondering, could there be some form of "ghost lobes" outside the drive that extend the resonance pattern we are seeing inside it.

This is probably better off on reddit than here, but here goes anyway:

Let me make a prediction about that Yang/Shell.  I bet that if you animate it, it would look like lobes form at the small baseplate, and exit the frustum at the large plate.  Let me also go out on a limb and suggest that a successful EMDrive will be one who's geometry causes causes the photons in the lobes (or at least some of them) to hit at greater than the critical angle to create an evanescent wave, and then resonance (i.e. bouncing off the end plate) is somehow maintained on the other side of the plate

I've mentioned this idea before, but it needs some math backing to be taken seriously. I wonder if the evanescent photons escape the cavity by a tunnelling-like mechanism at superluminal velocity, then loop back to the cavity at light speed. It is only during the tunnelling process that the photons are superluminal carrying superluminal momentum (JMO).

That idea leaves open more than one idea for the thrust creation. It could be simply momentum variation of the evanescent photons, as I allude above, or perhaps the exchange of energy mass from the inside to outside results in a gravitational effect on the cavity.  But I am not competent to broach this subject mathematically.

So um, stick an RF detector where we thinking this might be happening (which is hopefully not nanometers from the plate).  If it goes off thing get interesting.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/18/2015 07:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427481#msg1427481">Quote from: SteveD on 09/18/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427470#msg1427470">Quote from: CraigPichach on 09/18/2015 07:26 PM</a>

If we don't need to target shape modes, yet the "EM-Drive/Q-Thruster" phenomena only occurs at a particular frequency for a particular dimension than isn't it amazing we've managed to find anything at all? Indeed is not the logical experiment than to fire RF all across the spectrum for a dimension and see if, when and where we see thrust given all bets are off as to when we see something (and given anything seen was basically completely by chance?!?!?)

Well, given the use of a noisy magnetron. . .

And I wonder what happened to Dr. Notsosureofit's theory which did consider mode shapes? Is his theory now falsified?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/18/2015 07:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427482#msg1427482">Quote from: SteveD on 09/18/2015 07:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427473#msg1427473">Quote from: aero on 09/18/2015 07:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427460#msg1427460">Quote from: SteveD on 09/18/2015 06:55 PM</a>
Just a thought on mode.  I think the EMDrive might be a form of reflected energy thruster.  (Similar to a photononic laser thruster).  Something massless and traveling at the speed of light is, somehow, exiting the drive and being reflected back for additional bounces.  Instead of a mirror we are using some kind of electromagnetic effect that reflects photons and is moving away from the drive opposite the direction of travel.

Well, there is the thought/claim that evanescent waves stay attached, looping outward and back, redepositing their energy.
Quote

So that got me wondering, could there be some form of "ghost lobes" outside the drive that extend the resonance pattern we are seeing inside it.

This is probably better off on reddit than here, but here goes anyway:

Let me make a prediction about that Yang/Shell.  I bet that if you animate it, it would look like lobes form at the small baseplate, and exit the frustum at the large plate.  Let me also go out on a limb and suggest that a successful EMDrive will be one who's geometry causes causes the photons in the lobes (or at least some of them) to hit at greater than the critical angle to create an evanescent wave, and then resonance (i.e. bouncing off the end plate) is somehow maintained on the other side of the plate

I've mentioned this idea before, but it needs some math backing to be taken seriously. I wonder if the evanescent photons escape the cavity by a tunnelling-like mechanism at superluminal velocity, then loop back to the cavity at light speed. It is only during the tunnelling process that the photons are superluminal carrying superluminal momentum (JMO).

That idea leaves open more than one idea for the thrust creation. It could be simply momentum variation of the evanescent photons, as I allude above, or perhaps the exchange of energy mass from the inside to outside results in a gravitational effect on the cavity.  But I am not competent to broach this subject mathematically.

So um, stick an RF detector where we thinking this might be happening (which is hopefully not nanometers from the plate).  If it goes off thing get interesting.

Unfortunately it will go off, otherwise the DYI'ers wouldn't be challenged with EM interference issues.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Notsosureofit on 09/18/2015 08:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427483#msg1427483">Quote from: aero on 09/18/2015 07:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427481#msg1427481">Quote from: SteveD on 09/18/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427470#msg1427470">Quote from: CraigPichach on 09/18/2015 07:26 PM</a>

If we don't need to target shape modes, yet the "EM-Drive/Q-Thruster" phenomena only occurs at a particular frequency for a particular dimension than isn't it amazing we've managed to find anything at all? Indeed is not the logical experiment than to fire RF all across the spectrum for a dimension and see if, when and where we see thrust given all bets are off as to when we see something (and given anything seen was basically completely by chance?!?!?)

Well, given the use of a noisy magnetron. . .

And I wonder what happened to Dr. Notsosureofit's theory which did consider mode shapes? Is his theory now falsified?

Nope, just waiting for data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/18/2015 08:49 PM

ALL of NASA Eagleworks experiments in vacuum have been performed with only (1) one mode shape: TM212

How can one make ANY scientifcally valid statements about "thrust" for other mode shapes when they have performed all their experiments in vacuum using just (1) one mode shape ???

Furthermore:

1) Paul March has repeatedly stated that NASA Eagleworks data does not support a unique monotonic relationship between "thrust" and Q resonance.

2) ALL of NASA Eagleworks experiments reporting thrust have been performed with dielectric inserts.  Without dielectric inserts they actually reported NO thrust.   The thrust/powerInput reported by TU Dresden (Tajmar) without dielectric inserts, in vacuum, is much, much smaller than NASA Eagleworks.
No, there is no fundamental shifting, unless you take statements out of their specific context and conditions under which the statements were made.

It is scientifically incorrect to generalize statements outside the conditions (theoretical and experimental) that supported the statements in the  (theoretical and experimental) context in which they were made.



<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427470#msg1427470">Quote from: CraigPichach on 09/18/2015 07:26 PM</a>
Dr. Rodal, the ramifications of your claim that mode shape does not impact potential thrust are huge in my opinion.

Why do you think the NASA Eagleworks experiment then saw thrust at one particular frequency for one particular dimension that happened to be a shape mode?

Do you still agree that you need to target one or certain frequencies for certain frustrum dimensions to see EM-Drive/Q-Thruster phenomena but it isn't a shape mode as we define it or are you saying that its just resonance or the effect simply doesn't exist at all so it all doesn't matter?

If we don't need to target shape modes, yet the "EM-Drive/Q-Thruster" phenomena only occurs at a particular frequency for a particular dimension than isn't it amazing we've managed to find anything at all? Indeed is not the logical experiment than to fire RF all across the spectrum for a dimension and see if, when and where we see thrust given all bets are off as to when we see something (and given anything seen was basically completely by chance?!?!?) i.e. Was Paul March wasting his time coming up with all those shape modes?

What happened to all the talk on "thrust force measurements are related to the TRANSVERSE ELECTRIC modes, since their mode shape result in greater thrust force/PowerInput than the TRANSVERSE MAGNETIC mode shapes."

Would you agree that this is a fundamental shift in even your original thinking - I mean why did you come up with an exact solution for shape modes then relating to Q-Thruster/EM-Drive?

(Side note - huge ramifications if resonance shape and just resonance explains "thrust" with respect to Eagleworks claims to magnetohydrodynamics and QV fluidization at work).

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427431#msg1427431">Quote from: Rodal on 09/18/2015 04:47 PM</a>
Mr. Pichach,  the literature points out that there is NO particular mode shape that is predicted to provide more thrust.  On the contrary:



1) NASA Eagleworks is the only testing organization that has actually experimentally verified the mode shape that they excited: it was TM212, which is not even a TE mode.  Nobody else has experimentally verified what mode shape was excited.  Talk about mode shapes by others (except NASA Eagleworks) is just that: talk, and it cannot be scientifically accepted as corroboration of a any mode shape, particularly when Finite Element and exact solution analysis shows that there are several mode shapes in the frequency range of testing.

2) Neither R. Shawyer nor Prof.. Yang ever conducted a single test in a partial vacuum.  Their test claims have NOT been replicated by any scientific organization whatsoever.  If anything, the tests at TU Dresden and at NASA Eagleworks (resulting in thrust force/InputPower that are orders of magnitude smaller than the claims of Shawyer and Yang) have served as a scientific refutation of the claims by Shawyer and Yang, that one must objectively (in light of experiemental attempts at replication) to be subject to the well known "gas effect" (thermal convection, etc.) that has been known to plague all experimental measurements of electromagnetic pressure ever since it was predicted by Maxwell.



Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/18/2015 08:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427483#msg1427483">Quote from: aero on 09/18/2015 07:44 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427481#msg1427481">Quote from: SteveD on 09/18/2015 07:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427470#msg1427470">Quote from: CraigPichach on 09/18/2015 07:26 PM</a>

If we don't need to target shape modes, yet the "EM-Drive/Q-Thruster" phenomena only occurs at a particular frequency for a particular dimension than isn't it amazing we've managed to find anything at all? Indeed is not the logical experiment than to fire RF all across the spectrum for a dimension and see if, when and where we see thrust given all bets are off as to when we see something (and given anything seen was basically completely by chance?!?!?)

Well, given the use of a noisy magnetron. . .

And I wonder what happened to Dr. Notsosureofit's theory which did consider mode shapes? Is his theory now falsified?

the mode dependence implied by Dr. Notsosureofit's theory, does NOT support the mode dependence being advocated by some people in these pages (e.g.: TE013 ???  )

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/18/2015 09:00 PM

Dr. Rodal,

I'm not saying your wrong, I just want to ensure understanding.

To come right down to it, do you believe that NASA Eagleworks targeting a mode shape is a mistake and that we should be targeting dimensions @ frequencies based on another concept?

I think that is huge if it turns out that thrust is independent of mode shape; and I'd urge experiments to determine just when/where do we see thrust at dimensions @ frequencies regardless of mode shape.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427509#msg1427509">Quote from: Rodal on 09/18/2015 08:49 PM</a>
ALL of NASA Eagleworks experiments in vacuum have been performed with only (1) one mode shape: TM212

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/18/2015 09:01 PM

Dr Notsosureof it,

Based on your theory (which I see on the Wiki now) care to hypothesize thrust for:

100kW
TE012 mode -big diameter 0.696m, small diameter 0.3953m, length 0.569m, 930MHz
TE013 big diameter 0.696m, small diameter 0.3953m, length 0.8538m, 930MHz

Also any thoughts as to what you'd get with a 1MW, 10 microsecond pulse?


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427492#msg1427492">Quote from: Notsosureofit on 09/18/2015 08:01 PM</a>


Nope, just waiting for data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Rodal on 09/18/2015 09:06 PM

How can one make ANY scientifcally valid statements about "thrust" for other mode shapes when NASA has performed all their experiments in vacuum using just (1) one mode shape ???

and ONLY NASA has experimentally verified the mode shape???

and ONLY NASA and TU Dresden have reported experiments in vacuum ??? (but TU Dresden did not experimentally verify what mode shape was excited)

(as discussed NOBODY else -other than NASA- has bothered to experimentally verify the mode shape excited)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427513#msg1427513">Quote from: CraigPichach on 09/18/2015 09:00 PM</a>
Dr. Rodal,

I'm not saying your wrong, I just want to ensure understanding.

To come right down to it, do you believe that NASA Eagleworks targeting a mode shape is a mistake and that we should be targeting dimensions @ frequencies based on another concept?

I think that is huge if it turns out that thrust is independent of mode shape; and I'd urge experiments to determine just when/where do we see thrust at dimensions @ frequencies regardless of mode shape.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427509#msg1427509">Quote from: Rodal on 09/18/2015 08:49 PM</a>
ALL of NASA Eagleworks experiments in vacuum have been performed with only (1) one mode shape: TM212

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/18/2015 09:19 PM

Dr. Rodal,

Should not the concern be then that why aren't we all designing frustrums @ frequency for TM212 ("NASA has performed all their experiments in vacuum using just (1) one mode shape") as opposed to expecting that a frustrum designed for a mode shape at one frequency would work for other frequencies given the same dimensions?

I don't see how anyone can make scientifically valid statements right now without more data which is what we are seeking here and it seems like part of the more data is trying more mode shapes? Isn't that why NASA Eagleworks was calculating mode shapes? I don't see the big tragedy in wanting to see more experiments at mode shapes and the hypothesis that given thrust was achieved at a mode shape, that mode shape is a potential function?


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427517#msg1427517">Quote from: Rodal on 09/18/2015 09:06 PM</a>
How can one make ANY scientifcally valid statements about "thrust" for other mode shapes when NASA has performed all their experiments in vacuum using just (1) one mode shape ???

and ONLY NASA has experimentally verified the mode shape???

and ONLY NASA and TU Dresden have reported experiments in vacuum ??? (but TU Dresden did not experimentally verify what mode shape was excited)

(as discussed NOBODY else has bothered to experimentally verify the mode shape excited)


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427513#msg1427513">Quote from: CraigPichach on 09/18/2015 09:00 PM</a>
Dr. Rodal,

I'm not saying your wrong, I just want to ensure understanding.

To come right down to it, do you believe that NASA Eagleworks targeting a mode shape is a mistake and that we should be targeting dimensions @ frequencies based on another concept?

I think that is huge if it turns out that thrust is independent of mode shape; and I'd urge experiments to determine just when/where do we see thrust at dimensions @ frequencies regardless of mode shape.


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427509#msg1427509">Quote from: Rodal on 09/18/2015 08:49 PM</a>
ALL of NASA Eagleworks experiments in vacuum have been performed with only (1) one mode shape: TM212

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/18/2015 10:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427485#msg1427485">Quote from: aero on 09/18/2015 07:47 PM</a>

Unfortunately it will go off, otherwise the DYI'ers wouldn't be challenged with EM interference issues.

What about that idea a while back to use carbon paper to image the mode shape?  Put it above a test unit and if it looks like a mode then it isn't random scatter.  (For all we know reflection of the RF leakage might be what's causing the suspected effect).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/18/2015 11:08 PM
TE103 is a typo. Go with TE013.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 09/19/2015 03:46 AM

Quote
I can support wallofwolfstreet's comment that these so called "simulations" do not represent a real physics process.

Professionally, I'm using a similar 3D program with an almost identical rigid & softbody dynamics module.
The confusing originates from the arbitrary use of the word "simulation".

There is a distinct difference between an animation and a simulation:

An animation is designed with a certain intend. Their dynamics module is not designed for physical accuracy, but for efficiency and speed, consequently, these processes are hugely simplified.
From the outside they do appear to be simulations, but in reality , they're not...

A simulation uses genuine physics data and formulas in an attempt to replicate real events. It has no intend. There are software packages that are capable of simulating real natural events (fluid dynamics, nuclear explosion, etc) but these usually need a massive amount of computing power for days.

These 3D packages are all ANIMATION software packages, designed to make or support story telling.
Their dynamic modules are designed to be near real time and do cut a lot of corners to achieve that.

Sadly,  animations are often disguised and sold as "simulations", because those carry a lot more public credibility, because they're used in the scientific, industrial and military world.

Bottom line:
I would not base any scientific conclusion based on the dynamics engine you find in Maya, 3DStudio, Softimage, etc.
Their proper use of those software packages is to make wonderful renders of how the EMdrive spaceship IXS Clark would/could look like...To tell a story, to spark imagination....

not to simulate a difficult and complex physics problem...

Thank you for clearing that up.  I was looking at the video and going....'this has to be wrong, but I can't figure out how, unless there really is some weird loophole.' 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DavidR NASA on 09/19/2015 10:59 AM
Good morning guys. Been following some of this since the article was published on site, but saw it referenced in a advanced concept meeting yesterday. Nothing specific, but direct mention and a reference to this site. Would anyone be kind enough to proivde a one post overview of current status per your testing and evaluations?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/19/2015 11:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427639#msg1427639">Quote from: DavidR NASA on 09/19/2015 10:59 AM</a>
Good morning guys. Been following some of this since the article was published on site, but saw it referenced in a advanced concept meeting yesterday. Nothing specific, but direct mention and a reference to this site. Would anyone be kind enough to proivde a one post overview of current status per your testing and evaluations?
The wiki page may be of interest :)
http://emdrive.wiki/Main_Page

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/19/2015 12:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427639#msg1427639">Quote from: DavidR NASA on 09/19/2015 10:59 AM</a>
Good morning guys. Been following some of this since the article was published on site, but saw it referenced in a advanced concept meeting yesterday. Nothing specific, but direct mention and a reference to this site. Would anyone be kind enough to provide a one post overview of current status per your testing and evaluations?

As I do not own a science degree, I'll not risk making a status report of the past months. I might inadvertently misinterpret some findings...

I guess that Dr. Rodal is the best placed person to give you a scientific rundown of this forums findings so far, since the publication of the article.

But a good alternative are the weekly summaries of this forum, that you can find on Reddit.

try this:
https://www.reddit.com/r/EmDrive/search?q=As+The+Frustum+Turns

It is an excellent way of keeping informed, without plowing through pages and pages of discussions on this forum...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/19/2015 12:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427639#msg1427639">Quote from: DavidR NASA on 09/19/2015 10:59 AM</a>
Good morning guys. Been following some of this since the article was published on site, but saw it referenced in a advanced concept meeting yesterday. Nothing specific, but direct mention and a reference to this site. Would anyone be kind enough to proivde a one post overview of current status per your testing and evaluations?
Sure.
I'm one of the builders of a test stand and Drive. Since this picture was taken a little over 2 weeks ago I've completed the testing of the Faraday cage (the large white structure in the foreground). This surrounds the composite fulcrum arm with the frustum attached to it. The fulcrum arm is a multiple section secured carbon fiber wound fulcrum pivoting on 2 knife edges. The fulcrum allows 2 modes of measuring force and movement. It can be allowed to freely move providing a acceleration curve or set on a digital scale to measure force down to .01 mg.

I'm driving the frustum that negates thermal expansion of the side walls by attaching the 2 resonator plates with a 1/2" quartz rod that is allowed to turn and adjust the small plate and thereby the cavity length for fine tuning of the frustum. The end plates are made of ceramic plates 165mm and 312mm plated with copper. The small plate is attached to the sliding end cavity by using a Beryllium flexible seal to allow thermal expansion of the outer O2 free copper walls of the cavity.

I'm driving the frustum with a inverter style power supply into a magnetron into a waveguide>coax to the frustum that will allow me to vary power to a multiple set of  phased, highly modified loop antennas through the small plate. These antennas lock in a Mode TE012 within the frustum.

My second phase is to inject directly into the sidewalls of the frustum with opposing waveguides.

Currently I'm finishing up on the final evaluations and testing of the test rig and waiting for the waveguide and a few other parts. If the hardware arrives soon I'll begin powered testing in 2-3 weeks.

Shell
http://imgur.com/a/hDkTG

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/19/2015 01:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427639#msg1427639">Quote from: DavidR NASA on 09/19/2015 10:59 AM</a>
Good morning guys. Been following some of this since the article was published on site, but saw it referenced in a advanced concept meeting yesterday. Nothing specific, but direct mention and a reference to this site. Would anyone be kind enough to proivde a one post overview of current status per your testing and evaluations?
Welcome to the forum! My build/testing videos are here:

https://www.youtube.com/watch?v=QFPTQMX8R0I

It starts out as static thermal testing, then moves to balance beam testing. Build started in June of this year. Test stand now being upgraded to datalog displacement of balance beam at micrometer level resolution.

Experiment is named NSF-1701, which can be searched on this forum and googled elsewhere:

https://www.google.com/search?q=%22nsf-1701%22&sourceid=ie7&rls=com.microsoft:en-US:IE-Address&ie=&oe=&gws_rd=ssl

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/19/2015 03:26 PM
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/19/2015 07:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/19/2015 07:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

But I'm looking for Cherenkov radiation from superluminal evanescent photons. Of course, being photons, they might not radiate other photons.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/19/2015 07:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427773#msg1427773">Quote from: aero on 09/19/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

But I'm looking for Cherenkov radiation from superluminal evanescent photons. Of course, being photons, they might not radiate other photons.

I can understand this type of radiation for particles with restmass traveling faster than light in a medium like "hot" particles in water.
You're really looking for photons who emit photons ??? ?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 09/19/2015 07:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427781#msg1427781">Quote from: X_RaY on 09/19/2015 07:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427773#msg1427773">Quote from: aero on 09/19/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

But I'm looking for Cherenkov radiation from superluminal evanescent photons. Of course, being photons, they might not radiate other photons.

I can understand this type of radiation for particles with restmass traveling faster than light in a medium like "hot" neutrons in water.
You're realy looking for photons who emit photons ??? ?

Neutrons and photons do not produce Cherenkov radiation. Charged particles such as electrons produce Cherenkov radiation when move they through a medium at a speed higher than the speed of light in that medium.

We're not going to see that in an EM drive.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/19/2015 08:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427798#msg1427798">Quote from: RonM on 09/19/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427781#msg1427781">Quote from: X_RaY on 09/19/2015 07:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427773#msg1427773">Quote from: aero on 09/19/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

But I'm looking for Cherenkov radiation from superluminal evanescent photons. Of course, being photons, they might not radiate other photons.

I can understand this type of radiation for particles with restmass traveling faster than light in a medium like "hot" neutrons in water.
You're realy looking for photons who emit photons ??? ?

Neutrons and photons do not produce Cherenkov radiation. Charged particles such as electrons produce Cherenkov radiation when move they through a medium at a speed higher than the speed of light in that medium.

We're not going to see that in an EM drive.
Thanks for refreshing my memory, you are right!  ::)
(german)wikipedia:
"In a broader sense Cherenkov radiation is the electromagnetic radiation that occurs when charged particles moving in matter at a higher speed than the phase velocity of electromagnetic waves in this medium. More generally, it spoke of the Cherenkov effect. For example, the speed of light in water is only 225,000,000 m / s, compared to 299,792,458 m / s in a vacuum."

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/19/2015 10:41 PM
I thought an evanescent effect in the borders of the frustrum materials was one of the proposed mechanisms for the thrust in the earlier threads. If so wouldn't that be a situation in which one might expect cherenkov radiation from boundary layer electrical effects? Don't evanescent waves in a solid conductor like the frustrum material have electrical secondary effects? Since the evanescent effect itself may be FTL then it would seem to me that since the speed of light varies from that of vacuum in a solid then there is an opportunities for electrons to be moving FTL (for the solid medium.)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 09/20/2015 02:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427359#msg1427359">Quote from: Devilstower on 09/18/2015 10:18 AM</a>
Quote rom @flyby
There is a distinct difference between an animation and a simulation:

An animation is designed with a certain intend. Their dynamics module is not designed for physical accuracy, but for efficiency and speed, consequently, these processes are hugely simplified.
From the outside they do appear to be simulations, but in reality , they're not...
Absolutely right. The focus of these applications is to provide the appearance of real materials, not to simulate them on every level. Depending on the strength of the program, simple properties like density can be well represented, but even properties that affect physical transformation — say, something like ductility — may be poor to nonexistent. 

There's just enough in the best animation systems to fool you into believing they model reality, and not a penny more. I've yet to run into one that could adequately model the behavior of simple projectiles in air, much less an EM drive.

I am not sure anyone was looking at this as a high fidelity simulation but a basic proof of concept.  Still the null tests were all null and interestingly the fustrum was the best of the asymmetric shape for the level of resolution and fidelity, etc. of the simulation.  (I still have a sweet spot in my heart for the trombone shape.)

In any case, there is enough here to raise a flag for anyone planning to do null tests with a fustrum and a heater.  There may be other effects beside ballooning going on that may need to be accounted for.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/20/2015 02:32 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427894#msg1427894">Quote from: demofsky on 09/20/2015 02:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427359#msg1427359">Quote from: Devilstower on 09/18/2015 10:18 AM</a>
Quote rom @flyby
There is a distinct difference between an animation and a simulation:

An animation is designed with a certain intend. Their dynamics module is not designed for physical accuracy, but for efficiency and speed, consequently, these processes are hugely simplified.
From the outside they do appear to be simulations, but in reality , they're not...
Absolutely right. The focus of these applications is to provide the appearance of real materials, not to simulate them on every level. Depending on the strength of the program, simple properties like density can be well represented, but even properties that affect physical transformation — say, something like ductility — may be poor to nonexistent. 

There's just enough in the best animation systems to fool you into believing they model reality, and not a penny more. I've yet to run into one that could adequately model the behavior of simple projectiles in air, much less an EM drive.

I am not sure anyone was looking at this as a high fidelity simulation but a basic proof of concept.  Still the null tests were all null and interestingly the fustrum was the best of the asymmetric shape for the level of resolution and fidelity, etc. of the simulation.  (I still have a sweet spot in my heart for the trombone shape.)

In any case, there is enough here to raise a flag for anyone planning to do null tests with a fustrum and a heater.  There may be other effects beside ballooning going on that may need to be accounted for.
Have not followed this subtopic close enough to understand what other effects besides thermal might be occurring.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/20/2015 02:38 AM

Hi all.  This paper seems interesting:

Quantum reflection of photons off spatio-temporal electromagnetic field inhomogeneities

Quote
We reconsider the recently proposed nonlinear QED effect of quantum reflection of photons off an inhomogeneous strong-field region. We present new results for strong fields varying both in space and time. While such configurations can give rise to new effects such as frequency mixing, estimated reflection rates based on previous one-dimensional studies are corroborated. On a conceptual level, we critically re-examine the validity regime of the conventional locally-constant-field approximation and identify kinematic configurations which can be treated reliably. Our results further underline the discovery potential of quantum reflection as a new signature of the nonlinearity of the quantum vacuum.

http://arxiv.org/abs/1412.0951 (http://arxiv.org/abs/1412.0951)

From what I can gather, they are talking about a quantum effect that might be able to operate either as a mirror, or more likely a prism.  They mention photons being deflected 90 degrees, so photon hits the small end, flies towards the big end, gets deflected 90 degrees, and you end up with the forward and side forces reported by Tajmar.  I wonder if the waste heat in the system could become caught in this.  Might explain why thrust seems to increase when a thermally insulating dielectric is placed over one of the ends that would otherwise be acting as a heatsink (on the other hand if there is something reflecting IR photons outside of the frustum, an insulator might not be a good idea).

Anyway, I could be completely wrong.  This paper is pretty deep and the authors are speaking in math.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 09/20/2015 02:54 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427841#msg1427841">Quote from: Stormbringer on 09/19/2015 10:41 PM</a>
I thought an evanescent effect in the borders of the frustrum materials was one of the proposed mechanisms for the thrust in the earlier threads. If so wouldn't that be a situation in which one might expect cherenkov radiation from boundary layer electrical effects? Don't evanescent waves in a solid conductor like the frustrum material have electrical secondary effects? Since the evanescent effect itself may be FTL then it would seem to me that since the speed of light varies from that of vacuum in a solid then there is an opportunities for electrons to be moving FTL (for the solid medium.)

Cherenkov radiation occurs in dielectric medium. Copper is a conductor.

Why would evanescent waves increase the velocity of electrons in copper?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/20/2015 04:07 AM
water is a conductor. i see blue glow stuff in water around reactor rods. why?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RonM on 09/20/2015 04:33 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427928#msg1427928">Quote from: Stormbringer on 09/20/2015 04:07 AM</a>
water is a conductor. i see blue glow stuff in water around reactor rods. why?

Water is a very poor conductor unless it has impurities. It is also transparent.

Last time I looked, copper is not transparent.

Look up Cherenkov radiation, evanescent waves, and electrons see if you can support your conjectures.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 09/20/2015 05:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427903#msg1427903">Quote from: rfmwguy on 09/20/2015 02:32 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427894#msg1427894">Quote from: demofsky on 09/20/2015 02:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427359#msg1427359">Quote from: Devilstower on 09/18/2015 10:18 AM</a>
Quote rom @flyby
There is a distinct difference between an animation and a simulation:

An animation is designed with a certain intend. Their dynamics module is not designed for physical accuracy, but for efficiency and speed, consequently, these processes are hugely simplified.
From the outside they do appear to be simulations, but in reality , they're not...
Absolutely right. The focus of these applications is to provide the appearance of real materials, not to simulate them on every level. Depending on the strength of the program, simple properties like density can be well represented, but even properties that affect physical transformation — say, something like ductility — may be poor to nonexistent. 

There's just enough in the best animation systems to fool you into believing they model reality, and not a penny more. I've yet to run into one that could adequately model the behavior of simple projectiles in air, much less an EM drive.

I am not sure anyone was looking at this as a high fidelity simulation but a basic proof of concept.  Still the null tests were all null and interestingly the fustrum was the best of the asymmetric shape for the level of resolution and fidelity, etc. of the simulation.  (I still have a sweet spot in my heart for the trombone shape.)

In any case, there is enough here to raise a flag for anyone planning to do null tests with a fustrum and a heater.  There may be other effects beside ballooning going on that may need to be accounted for.
Have not followed this subtopic close enough to understand what other effects besides thermal might be occurring.

I don't think any of this would apply to your mesh fustrum but for solid fustrums there may be a kind an asymmetrical kinetic effect which may or may not be measurable.  More just something to watch for if the numbers don't add up. 

Really all we have is a Maya simulation of a bunch miniature billiard balls rattling around and having an effect.  Which is kind of amazing regardless of how crude an approximation a Maya simulation may be.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: PaulF on 09/20/2015 08:51 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427928#msg1427928">Quote from: Stormbringer on 09/20/2015 04:07 AM</a>
water is a conductor. i see blue glow stuff in water around reactor rods. why?
From what I know that is cherenkov radiation bleeding off energy of high energy particles so they travel at speeds lower than the speed of light in water or whatever medium the reaction is taking place in.

-edit- I now also realize I should have read back a bit more...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/20/2015 09:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427798#msg1427798">Quote from: RonM on 09/19/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427781#msg1427781">Quote from: X_RaY on 09/19/2015 07:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427773#msg1427773">Quote from: aero on 09/19/2015 07:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

But I'm looking for Cherenkov radiation from superluminal evanescent photons. Of course, being photons, they might not radiate other photons.

I can understand this type of radiation for particles with restmass traveling faster than light in a medium like "hot" neutrons in water.
You're realy looking for photons who emit photons ??? ?

Neutrons and photons do not produce Cherenkov radiation. Charged particles such as electrons produce Cherenkov radiation when move they through a medium at a speed higher than the speed of light in that medium.

We're not going to see that in an EM drive.

Thank you! Don't expect to see Cherenkov radiation which is associated with high energy stuff like fission reactors.

This is a pretty complicated issue. There's a lot going on inside my head lately so I'll just kinda throw it out there in case something happens to resonate with someone.  8) That's what forums are for anyway. I'm just trying to make sense of what I've learned over the last year. Trying to understand what might be happening to produce thrust from an air filled cavity senza dielectric insert is a beast.

The ionized air glow I'm looking for isn't related to this Cherenkov radiation. Just looking for evidence of charged particles to move around with the Lorentz force. When I apply the right hand rule (or left) to an imaginary charged particle under TE012, I get a trajectory that resembles a torus. I'm interested in TE012 because Eagleworks reported that it was the best performing mode in the Anomalous thrust production...paper, but they didn't do further tests! Shawyer also has reported that TE012 and TE013 are the best performing modes. I'm frustumrated at the lack of hard data to support the efficacy of these modes.

The broader reason why is because, out of all the numerous ideas (yeah I know  ;D) I've been kicking around to explain thrust from a Type 3 Emdrive (tapered cavity with no dielectric insert), the only one that comes close to passing the smell test for me is gravitomagnetism. If it weren't for Gravity Probe B, I'd say forget it. There's also fantastic reading on the subject such as this http://arxiv.org/pdf/gr-qc/0207065.pdf ....and the whole thing is seated in General Relativity.  :) Hell if this Emdrive ended up being just another test of General Relativity, I bet the scientific community would go nuts!

There are so many issues associated with gravitomagnetism (not to mention a boat load of woo* to the point where I feel hesitant to even bring it up for fear of being viewed as cranky) such as the very lack of rotating masses in the Emdrive (why I'm looking for evidence of charged particles). I'm wondering if a rotating mass is even necessary. Rotating energy should be enough right?

Then there's the whole effective mass for photons which I used to view as heresy until I found those papers about photon mass in waveguides. (A direct result of the "accelerating photons" feud I had with @Rodal.) So I'm on board with the notion that photons that are confined to a resonator behave differently than their free range counterparts.

Other issues include the thermal images from Eagleworks which clearly show there is no net rotation of the entire resonant mode as evidenced by clearly stationary hot spots. At the same time, Eagleworks reports no thrust without a dielectric and greatly diminished thrust in pumped down the vacuum chamber. Yang and Shawyer report lots of thrust with their unloaded cavities but Eagleworks doesn't. I'm looking for the secret sauce here.

My thinking on this is that the loop antenna method could be very bad as it forces the mode to be "locked" in position with the loop. I got a cloverleaf antenna on the way and my thinking is to place it a 1/4 wavelength from the center of the large end. Before I can test anything, I have to figure out this battery situation I got. https://www.reddit.com/r/EmDrive/comments/3lb769/emdrive_lurkers_posers/cv62gp8

* like the TR-3B, and this mess here which features a "flared waveguide" https://goo.gl/zl4qGi (see pages B-23 B-68 B-90  :o  I'm not a big fan of the woo btw, because I think it unnecessarily muddies the waters and obfuscates the truth. Somewhere in the 10 pounds of woo on this subject, there's bound to be an ounce of something that isn't bs right?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/20/2015 10:06 AM
I love "woo" :) It's delicious.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/20/2015 11:04 AM
Without a rtn loss scan of your hybrid mesh frustum, you really don't know that kind of load your magnetron is driving. Maybe it is the drugs they are feeding me to kill the 2nd belly button that is forming that makes me ask why would you spend the time & money to drive a Rf load that you have no knowledge of the resonant frequencies nor rtn loss / VSWR?

Sorry but I must ask where is the science based  test data?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/20/2015 11:33 AM
Gravitational Lorentz force is pretty interesting reading. Any experts out there?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 09/20/2015 12:09 PM
link might be of interest to those who like theorise on possible explanations on EM radiation and magnetic fields
might prompt a new thought or two.

http://phys.org/news/2015-09-route-magnets.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/20/2015 02:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

Why do you think the beryllium oxide was so glowing hot? A LOT of reflected power?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/20/2015 03:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427996#msg1427996">Quote from: Mulletron on 09/20/2015 02:19 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427751#msg1427751">Quote from: rfmwguy on 09/19/2015 07:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427674#msg1427674">Quote from: Mulletron on 09/19/2015 03:26 PM</a>
@rfmwguy did you ever witness any ionized air glow inside your see through frustum?
No, but I noticed the BeO ceramic on the mag radome glowing. I also noted an "air" of metallic-like feel around it. Some commented it may be ionized copper.

Why do you think the beryllium oxide was so glowing hot? A LOT of reflected power?
Not really sure on that one. Temp stabilized at abt 175 C, so it could be normal. Static tests I did had frustum shielded by copper and could not see it directly. Will video it next flight test. Am assembling DAQ and LDS display into an old PC today, waiting for replacement display, hopefully this week. Also got connectors for VNA testing on frustum. Next couple of weeks will be busy.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/20/2015 03:59 PM
Huh, so apparently there is an initial transient of reflected power until the cavity is filled. Good to know. Starts at slide 37

http://uspas.fnal.gov/materials/08UCSC/mml06_resonant_cavities_1.pdf

That's not good for users of magnetrons featuring a duty cycle.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/20/2015 04:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428016#msg1428016">Quote from: Mulletron on 09/20/2015 03:59 PM</a>
Huh, so apparently there is an initial transient of reflected power until the cavity is filled. Good to know. Starts at slide 37

http://uspas.fnal.gov/materials/08UCSC/mml06_resonant_cavities_1.pdf

That's not good for users of magnetrons featuring a duty cycle.
Why that? What do you think how many oscillations does it take to "fill" the cavity?
More than the 20 million during a single ON period(1/120 s) or much less? (half cycle at 60 Hz net frequency)

Thanks for the pdf-link!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: demofsky on 09/20/2015 08:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427972#msg1427972">Quote from: Mulletron on 09/20/2015 09:47 AM</a>
.....

The ionized air glow I'm looking for isn't related to this Cherenkov radiation. Just looking for evidence of charged particles to move around with the Lorentz force. When I apply the right hand rule (or left) to an imaginary charged particle under TE012, I get a trajectory that resembles a torus. I'm interested in TE012 because Eagleworks reported that it was the best performing mode in the Anomalous thrust production...paper, but they didn't do further tests! Shawyer also has reported that TE012 and TE013 are the best performing modes. I'm frustumrated at the lack of hard data to support the efficacy of these modes.

.....

Very interesting and thought provoking post!  However, I have to ask the question why anyone would expect anything but ions inside a non vacuum EM drive?  I have been assuming that all gases would automatically be ionized in that environment.  Am I missing something here?  Thanks!

https://en.m.wikipedia.org/wiki/Ion_source#Microwave_induced_plasma

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/20/2015 08:37 PM
Over the last several days I have generated a sequence of longer and longer runs using the Yang-Shell 6 degree model. csv files for all runs, png files for the longest run and a data description file are uploaded here.

https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing)

Fourteen runs were made for seven run lengths, 32, 64, 128 ... 2048 cycles of the drive frequency with the antenna located alternatively at the big and small end of the frustum. 

The png view files show some interesting characteristics that we haven't seen before, likely due to the runs approaching steady state, although with the high Q calculated for this model, a 2048 cycle run is far short of stead state.

One thing that I observed while making/correcting errors in location of the end cuts is the extensive amount of RF energy that meep calculates for outside of the frustum. The frustum is modelled as a solid metal (copper model) truncated cone centered in the computational lattice, then another solid air frustum centered in the computational lattice with diameters and height 1/2 inch smaller. That leaves 1/4 inch of copper model surrounding the air filled cavity and meep seems to think that there is RF energy escaping through the walls.  At meep resolution = 250, the 1/4 inch copper is over 5 pixels thick. It is interesting to note that classic Maxwell allows RF energy to propagate over five grid steps into the copper.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/20/2015 08:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428074#msg1428074">Quote from: aero on 09/20/2015 08:37 PM</a>
Over the last several days I have generated a sequence of longer and longer runs using the Yang-Shell 6 degree model. csv files for all runs, png files for the longest run and a data description file are uploaded here.

https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing)

Fourteen runs were made for seven run lengths, 32, 64, 128 ... 2048 cycles of the drive frequency with the antenna located alternatively at the big and small end of the frustum. 

The png view files show some interesting characteristics that we haven't seen before, likely due to the runs approaching steady state, although with the high Q calculated for this model, a 2048 cycle run is far short of stead state.

One thing that I observed while making/correcting errors in location of the end cuts is the extensive amount of RF energy that meep calculates for outside of the frustum. The frustum is modelled as a solid metal (copper model) truncated cone centered in the computational lattice, then another solid air frustum centered in the computational lattice with diameters and height 1/2 inch smaller. That leaves 1/4 inch of copper model surrounding the air filled cavity and meep seems to think that there is RF energy escaping through the walls.  At meep resolution = 250, the 1/4 inch copper is over 5 pixels thick. It is interesting to note that classic Maxwell allows RF energy to propagate over five grid steps into the copper.
What do you have changed? That pic is what we are looking for the TE01 mode :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/20/2015 08:57 PM
Spent some time today putting LDS display and DAQ module into an ancient PC. Its fast enough to datalog and also provide power to sensors. Hey, check out the cool floppy drive!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/20/2015 08:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428076#msg1428076">Quote from: X_RaY on 09/20/2015 08:46 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428074#msg1428074">Quote from: aero on 09/20/2015 08:37 PM</a>
Over the last several days I have generated a sequence of longer and longer runs using the Yang-Shell 6 degree model. csv files for all runs, png files for the longest run and a data description file are uploaded here.

https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing)

Fourteen runs were made for seven run lengths, 32, 64, 128 ... 2048 cycles of the drive frequency with the antenna located alternatively at the big and small end of the frustum. 

The png view files show some interesting characteristics that we haven't seen before, likely due to the runs approaching steady state, although with the high Q calculated for this model, a 2048 cycle run is far short of stead state.

One thing that I observed while making/correcting errors in location of the end cuts is the extensive amount of RF energy that meep calculates for outside of the frustum. The frustum is modelled as a solid metal (copper model) truncated cone centered in the computational lattice, then another solid air frustum centered in the computational lattice with diameters and height 1/2 inch smaller. That leaves 1/4 inch of copper model surrounding the air filled cavity and meep seems to think that there is RF energy escaping through the walls.  At meep resolution = 250, the 1/4 inch copper is over 5 pixels thick. It is interesting to note that classic Maxwell allows RF energy to propagate over five grid steps into the copper.
What do you have changed? That pic is what we are looking for the TE01 mode :)

I made every effort to change nothing. The only chance I know of is the drive frequency set to 2.45 GHz. That may be different. The length of the run, being 70 times longer than the 32 cycle runs I normally post, is the real change.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/20/2015 09:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427340#msg1427340">Quote from: TheTraveller on 09/18/2015 05:36 AM</a>
...

All the SC EMDrive stuff produced by RS since the Flight Thruster, uses Rf injection in the middle of the frustum side wall, which would inject the Rf into the middle lode of the 3 lobes of the TE013 mode. Also means at that injection point, it is the same / equal guide wavelength to/from both end plates.

I suspect doing it this way would reduce phase distortion from the Rf injection, on the already resonant standing wave, and increase the effective antenna coupling factor, lifting the loaded / operational Q value toward the max unloaded Q value.
...

I'm unclear about the advantage of a TE013 over a TE011. Wouldn't a TE011 also have equal guide wavelengths to/from both end plates?

Would increasing the effective antenna coupling factor also increase the quality when using a waveguide delivery which is already critically coupled to the frustum? Yang indicated that a TE011 resulted in the highest quality in her simulations, and she used a waveguide delivery.

Would increasing the Q factor be worth separating the maximum E field strength into three lobes?
I guess this last question ultimately boils down to what Mulletron is getting at: we still don't know what causes thrust so we can't really say which mode is better for 'thrust production'. Some modes might have the potential for higher quality or easier coupling etc...

What if the secret sauce is having one lobe spanning the maximum height of the frustum?
Perhaps it has to do with two counter rotating lobes?
Maybe having many counter rotating lobes would be ideal?
------------------------------------------------------------------------------------------------------------------------------

How could a dielectric 'mimic' the output of a magnetron?
The fact that EW couldn't get thrust with a TE012 mode without the dielectric means we should blame the source.
I think the secret to thrust lies in figuring out how a dielectric + amp = (a less efficient) magnetron

OR
Could their TE012 mode actually be a different mode? According to the paper, their TE012 was at 1.88 GHz but on the comsol plots they have TE012 at 2.18 GHz. Did the latter dimensions come after the experiment? 
If they actually didn't excite a TE mode, the need for a dielectric could be completely due to the mode. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/20/2015 09:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428074#msg1428074">Quote from: aero on 09/20/2015 08:37 PM</a>
Over the last several days I have generated a sequence of longer and longer runs using the Yang-Shell 6 degree model. csv files for all runs, png files for the longest run and a data description file are uploaded here.

https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing (https://drive.google.com/folderview?id=0B1XizxEfB23tRm41bVFtM1pVYlU&usp=sharing)

Fourteen runs were made for seven run lengths, 32, 64, 128 ... 2048 cycles of the drive frequency with the antenna located alternatively at the big and small end of the frustum. 

The png view files show some interesting characteristics that we haven't seen before, likely due to the runs approaching steady state, although with the high Q calculated for this model, a 2048 cycle run is far short of stead state.

One thing that I observed while making/correcting errors in location of the end cuts is the extensive amount of RF energy that meep calculates for outside of the frustum. The frustum is modelled as a solid metal (copper model) truncated cone centered in the computational lattice, then another solid air frustum centered in the computational lattice with diameters and height 1/2 inch smaller. That leaves 1/4 inch of copper model surrounding the air filled cavity and meep seems to think that there is RF energy escaping through the walls.  At meep resolution = 250, the 1/4 inch copper is over 5 pixels thick. It is interesting to note that classic Maxwell allows RF energy to propagate over five grid steps into the copper.
Ok... this just peaked my interest in several ways.
1. why is meep calculating an abnormality (doesn't look like fractals) through the copper,  right at the Boundary of the modes? It maybe an artifact because penetration should only be around 1.5um into the copper.
 
2. I don't think I've seen a nice flip through the modes as this does. Makes me wonder if how it evolves through the cycles.

3. I'm going to have to dust off the Yang-Shell design and maybe look at it again.

Nice work! Weird artifacts outside the walls and I had to do a gif.

Shell

PS: Why don't we see the effects on the top and bottom of the cavity???

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 12:35 AM
I'm not sure what I'm seeing, more artifacts?

aero, does meep calculate past the skin depth or is it limited to the surface effects?

Shell

Added: Calling Dr. Who... ops, I mean Dr. Rodel. Do you have a thought about these, I sure don't know.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 12:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428115#msg1428115">Quote from: SeeShells on 09/21/2015 12:35 AM</a>
I'm not sure what I'm seeing, more artifacts?

aero, does meep calculate past the skin depth or is it limited to the surface effects?

Shell

As far as I know, meep calculates wherever Maxwell's equations takes it. The medium changes from air to copper but the equations do not. Dr. Rodal might be able to give a more complete answer.

Keep looking, there are some other, even more interesting views.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 01:10 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428117#msg1428117">Quote from: aero on 09/21/2015 12:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428115#msg1428115">Quote from: SeeShells on 09/21/2015 12:35 AM</a>
I'm not sure what I'm seeing, more artifacts?

aero, does meep calculate past the skin depth or is it limited to the surface effects?

Shell

As far as I know, meep calculates wherever Maxwell's equations takes it. The medium changes from air to copper but the equations do not. Dr. Rodal might be able to give a more complete answer.

Keep looking, there are some other, even more interesting views.
I know... been looking at some.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 01:54 AM
This set. That's just weird.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 09/21/2015 02:04 AM
Do these "seepage anomalies" persist in higher resolution runs?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 02:22 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428133#msg1428133">Quote from: aero on 09/21/2015 01:54 AM</a>
This set. That's just weird.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 02:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428134#msg1428134">Quote from: RotoSequence on 09/21/2015 02:04 AM</a>
Do these "seepage anomalies" persist in higher resolution runs?

Don't know - 2000 cycles at resolution 250 took a day and a half on a good machine. I could run higher resolution for a shorter time. Probably 32 cycles at resolution 500 would take about the same day and a half.

That's a good thought though. Find an example in the 32 cycle run then compare it to a higher resolution, 32 cycle run.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 02:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428134#msg1428134">Quote from: RotoSequence on 09/21/2015 02:04 AM</a>
Do these "seepage anomalies" persist in higher resolution runs?
How much time would it take to increase the resolution. I know it increases exponentially with rez, but how much time is that, is it doable?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 02:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428140#msg1428140">Quote from: SeeShells on 09/21/2015 02:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428134#msg1428134">Quote from: RotoSequence on 09/21/2015 02:04 AM</a>
Do these "seepage anomalies" persist in higher resolution runs?
How much time would it take to increase the resolution. I know it increases exponentially with rez, but how much time is that, is it doable?

Shell
Just above. Run time increases with resolution as 23 for 3 dimensional models. That is linearly with the number of pixels in the 3-D grid. And it seems, linearly with # of cycles simulated. I could make a 32 cycle run at resolution 500, but I wouldn't want to start any higher than that.

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139 (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 03:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428145#msg1428145">Quote from: aero on 09/21/2015 02:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428140#msg1428140">Quote from: SeeShells on 09/21/2015 02:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428134#msg1428134">Quote from: RotoSequence on 09/21/2015 02:04 AM</a>
Do these "seepage anomalies" persist in higher resolution runs?
How much time would it take to increase the resolution. I know it increases exponentially with rez, but how much time is that, is it doable?

Shell
Just above. Run time increases with resolution as 23 for 3 dimensional models. That is linearly with the number of pixels in the 3-D grid. And it seems, linearly with # of cycles simulated. I could make a 32 cycle run at resolution 500, but I wouldn't want to start any higher than that.

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139 (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139)
Could our other "assistant" help in the time and memory needed by running it?
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 04:34 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428152#msg1428152">Quote from: SeeShells on 09/21/2015 03:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428145#msg1428145">Quote from: aero on 09/21/2015 02:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428140#msg1428140">Quote from: SeeShells on 09/21/2015 02:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428134#msg1428134">Quote from: RotoSequence on 09/21/2015 02:04 AM</a>
Do these "seepage anomalies" persist in higher resolution runs?
How much time would it take to increase the resolution. I know it increases exponentially with rez, but how much time is that, is it doable?

Shell
Just above. Run time increases with resolution as 23 for 3 dimensional models. That is linearly with the number of pixels in the 3-D grid. And it seems, linearly with # of cycles simulated. I could make a 32 cycle run at resolution 500, but I wouldn't want to start any higher than that.

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139 (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139)
Could our other "assistant" help in the time and memory needed by running it?
Shell

Maybe - Any volunteers with a lot of machine memory? Memory will be more of a problem than cpu because that goes up by the dimensions of the Yee lattice which is basically 2 grids, each 3-D superimposed. Computationally they are only one grid, but memory wise they are two. (I think that's right.)

Anyway, I wanted to tell all that I went ahead and created and uploaded png views for the 32 cycle run. They are in the same folder that I shared before, let me know if I must share it again. They used to look pretty good until I saw what happens when the model converges toward steady state with longer runs. Look to see if you can find a "seepage anomalies" artefact in the 32 cycle png views that would be worth looking at at higher resolution.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 05:01 AM
Both BE and SE

TE012?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: watermod on 09/21/2015 05:04 AM

It sounds like you really need a version of MEEP compiled for CUDA to run on NVIDIA graphics processors in your computers.
Sort of like this guy did years ago without MEEP http://m.gpucomputing.net/sites/default/files/papers/258/gpu_3dfd_rev.pdf (http://m.gpucomputing.net/sites/default/files/papers/258/gpu_3dfd_rev.pdf)
CUDA info here: http://www.nvidia.com/object/cuda_home_new.html (http://www.nvidia.com/object/cuda_home_new.html)

The only reference I saw, while searching (Google), to MEEP and CUDA was one of the MEEP developers saying he wasn't interested in such a port.

There appears to be another MEEP like program B-Calm that does use CUDA.  http://f.dominec.eu/meep/ (http://f.dominec.eu/meep/)
(from the webpage):
Quote
B-CALM

B-CALM is another FDTD simulation which employs CUDA for superfast computing on the graphical card. It communicates via a HDF5 file.
Comparing the features with MEEP, based on the website:

+ very fast GPU computation
- using CUDA, depends on Nvidia cards
- smaller user base

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 05:25 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428157#msg1428157">Quote from: SeeShells on 09/21/2015 05:01 AM</a>
Both BE and SE

TE012?

Don't know. That one really looks to me to be numeric in nature. If it is then higher resolution would just smooth it out.
 
That is, if you are addressing the jagged edges around the top of the gif. If you are asking a question about the mode, then pardon me. Someone else will need to answer that.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/21/2015 05:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428158#msg1428158">Quote from: watermod on 09/21/2015 05:04 AM</a>
It sounds like you really need a version of MEEP compiled for CUDA to run on NVIDIA graphics processors in your computers.
Sort of like this guy did years ago without MEEP http://m.gpucomputing.net/sites/default/files/papers/258/gpu_3dfd_rev.pdf (http://m.gpucomputing.net/sites/default/files/papers/258/gpu_3dfd_rev.pdf)
CUDA info here: http://www.nvidia.com/object/cuda_home_new.html (http://www.nvidia.com/object/cuda_home_new.html)

The only reference I saw, while searching (Google), to MEEP and CUDA was one of the MEEP developers saying he wasn't interested in such a port.

There appears to be another MEEP like program B-Calm that does use CUDA.  http://f.dominec.eu/meep/ (http://f.dominec.eu/meep/)
(from the webpage):
Quote
B-CALM

B-CALM is another FDTD simulation which employs CUDA for superfast computing on the graphical card. It communicates via a HDF5 file.
Comparing the features with MEEP, based on the website:

+ very fast GPU computation
- using CUDA, depends on Nvidia cards
- smaller user base

Yes. Quixote was working on porting meep to the graphics card, but he got really busy with his day job and so hasn't had much spare time to work on it lately.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/21/2015 06:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428036#msg1428036">Quote from: X_RaY on 09/20/2015 04:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428016#msg1428016">Quote from: Mulletron on 09/20/2015 03:59 PM</a>
Huh, so apparently there is an initial transient of reflected power until the cavity is filled. Good to know. Starts at slide 37

http://uspas.fnal.gov/materials/08UCSC/mml06_resonant_cavities_1.pdf

That's not good for users of magnetrons featuring a duty cycle.
Why that? What do you think how many oscillations does it take to "fill" the cavity?
More than the 20 million during a single ON period(1/120 s) or much less? (half cycle at 60 Hz net frequency)

The filling time could very well be infinite if there is no power being delivered from the magnetron at the narrow resonant frequency of the cavity. It is really a gamble when using a microwave oven magnetron. It is flying blind. If power delivered is less than power dissipated then there is no cavity fill. You can't even calculate it without knowing real values unique to the setup. The best you can do is arbitrarily calculate average power delivered using a made up pulse width and prt.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/21/2015 07:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428036#msg1428036">Quote from: X_RaY on 09/20/2015 04:56 PM</a>
Why that? What do you think how many oscillations does it take to "fill" the cavity?
More than the 20 million during a single ON period(1/120 s) or much less? (half cycle at 60 Hz net frequency)

Thanks for the pdf-link!

Cavity fill time is TC x 5. 1 TC is (2 Qloaded) / ( 2 Pi Freq) seconds. Then knowing the cavity TC and Freq, oscillations per 5 x TC sec cab be calced.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/21/2015 07:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428073#msg1428073">Quote from: demofsky on 09/20/2015 08:30 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427972#msg1427972">Quote from: Mulletron on 09/20/2015 09:47 AM</a>
.....

The ionized air glow I'm looking for isn't related to this Cherenkov radiation. Just looking for evidence of charged particles to move around with the Lorentz force. When I apply the right hand rule (or left) to an imaginary charged particle under TE012, I get a trajectory that resembles a torus. I'm interested in TE012 because Eagleworks reported that it was the best performing mode in the Anomalous thrust production...paper, but they didn't do further tests! Shawyer also has reported that TE012 and TE013 are the best performing modes. I'm frustumrated at the lack of hard data to support the efficacy of these modes.

.....

Very interesting and thought provoking post!  However, I have to ask the question why anyone would expect anything but ions inside a non vacuum EM drive?  I have been assuming that all gases would automatically be ionized in that environment.  Am I missing something here?  Thanks!

https://en.m.wikipedia.org/wiki/Ion_source#Microwave_induced_plasma

The thing is, is that there won't be any plasma if the field strengths aren't high enough.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mulletron on 09/21/2015 07:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428084#msg1428084">Quote from: zellerium on 09/20/2015 09:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1427340#msg1427340">Quote from: TheTraveller on 09/18/2015 05:36 AM</a>
...

All the SC EMDrive stuff produced by RS since the Flight Thruster, uses Rf injection in the middle of the frustum side wall, which would inject the Rf into the middle lode of the 3 lobes of the TE013 mode. Also means at that injection point, it is the same / equal guide wavelength to/from both end plates.

I suspect doing it this way would reduce phase distortion from the Rf injection, on the already resonant standing wave, and increase the effective antenna coupling factor, lifting the loaded / operational Q value toward the max unloaded Q value.
...

I'm unclear about the advantage of a TE013 over a TE011. Wouldn't a TE011 also have equal guide wavelengths to/from both end plates?

Would increasing the effective antenna coupling factor also increase the quality when using a waveguide delivery which is already critically coupled to the frustum? Yang indicated that a TE011 resulted in the highest quality in her simulations, and she used a waveguide delivery.

Would increasing the Q factor be worth separating the maximum E field strength into three lobes?
I guess this last question ultimately boils down to what Mulletron is getting at: we still don't know what causes thrust so we can't really say which mode is better for 'thrust production'. Some modes might have the potential for higher quality or easier coupling etc...

What if the secret sauce is having one lobe spanning the maximum height of the frustum?
Perhaps it has to do with two counter rotating lobes?
Maybe having many counter rotating lobes would be ideal?
------------------------------------------------------------------------------------------------------------------------------

How could a dielectric 'mimic' the output of a magnetron?
The fact that EW couldn't get thrust with a TE012 mode without the dielectric means we should blame the source.
I think the secret to thrust lies in figuring out how a dielectric + amp = (a less efficient) magnetron

OR
Could their TE012 mode actually be a different mode? According to the paper, their TE012 was at 1.88 GHz but on the comsol plots they have TE012 at 2.18 GHz. Did the latter dimensions come after the experiment? 
If they actually didn't excite a TE mode, the need for a dielectric could be completely due to the mode.

So there are two TE012s from Eagleworks. The comsol plot showing TE012 with the higher frequency is with an unloaded (no dielectric) cavity. The other TE012 with the lower frequency is with the dielectric insert. The dielectric insert lowers the natural frequencies of the cavity.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 09/21/2015 03:06 PM
Aachen EmDrive update. Just in case you missed it. Click the headline for YouTube video.
There is some music also. Check your volume first. Safety first  ;D

https://www.reddit.com/r/EmDrive/comments/3lpfpd/hackaday_emdrive_interferometer_tests_interesting/
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/21/2015 03:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428152#msg1428152">Quote from: SeeShells on 09/21/2015 03:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428145#msg1428145">Quote from: aero on 09/21/2015 02:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428140#msg1428140">Quote from: SeeShells on 09/21/2015 02:35 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428134#msg1428134">Quote from: RotoSequence on 09/21/2015 02:04 AM</a>
Do these "seepage anomalies" persist in higher resolution runs?
How much time would it take to increase the resolution. I know it increases exponentially with rez, but how much time is that, is it doable?

Shell
Just above. Run time increases with resolution as 23 for 3 dimensional models. That is linearly with the number of pixels in the 3-D grid. And it seems, linearly with # of cycles simulated. I could make a 32 cycle run at resolution 500, but I wouldn't want to start any higher than that.

http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139 (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428139#msg1428139)
Could our other "assistant" help in the time and memory needed by running it?
Shell

Yes, I could help out, if aero sends me the control file.  Should be able to let it run for a while with augmented memory.  Let me know if I can help.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/21/2015 03:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428222#msg1428222">Quote from: Chrochne on 09/21/2015 03:06 PM</a>
Aachen EmDrive update. Just in case you missed it. Click the headline for YouTube video.
There is some music also. Check your volume first. Safety first  ;D

https://www.reddit.com/r/EmDrive/comments/3lpfpd/hackaday_emdrive_interferometer_tests_interesting/
Really like these guys going to the interferometer. My hunch is that low power and high freq will need very fine measurement resolution. They'll need Shell's International Emdrive Flight Test Facility with her vertical supports buried in tons of concrete  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 03:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428225#msg1428225">Quote from: rfmwguy on 09/21/2015 03:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428222#msg1428222">Quote from: Chrochne on 09/21/2015 03:06 PM</a>
Aachen EmDrive update. Just in case you missed it. Click the headline for YouTube video.
There is some music also. Check your volume first. Safety first  ;D

https://www.reddit.com/r/EmDrive/comments/3lpfpd/hackaday_emdrive_interferometer_tests_interesting/
Really like these guys going to the interferometer. My hunch is that low power and high freq will need very fine measurement resolution. They'll need Shell's International Emdrive Flight Test Facility with her vertical supports buried in tons of concrete  8)
I watched a couple times and I'm still not sure what I'm seeing, I wish he would have had a VO (no not a drink) to explain what he was doing and what the tests were trying to show.
The're heading down the right track with the test bed layout, I like it.

I'll take some pictures today after I get back from town in what I ended up with the balance beam and digital scales. I'm using the digital scales and adjusting them up and down to work with the moving fulcrum beam to be able to get a profile and cross check the accuracy of the system.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/21/2015 05:04 PM
Just some thoughts about MEEP.

The thickness of drive wall is arbitrarily 1/4 inch so that it shows up as at least 1 pixel on the visual output.  Would be interesting to set it to a more realistic thickness and see what it does to the effect.

If these nodules are forming on the outside of the side wall of the device and Shawyer reports more thrust as the angle of those walls increase, it might argue that something is moving away from the walls and that the "flatter" the device the more that something is moving away in the direction of travel and not proving an offsetting force for that same something on the other side of the device.

Am I correct in thinking that MEEP has nothing (Null not vacuum) outside the frustum?  Maybe instead of upping the resolution of the run, the model should be placed in an air box so that we can see if those nodules are propagating through space.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/21/2015 05:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428160#msg1428160">Quote from: aero on 09/21/2015 05:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428157#msg1428157">Quote from: SeeShells on 09/21/2015 05:01 AM</a>
Both BE and SE

TE012?

Don't know. That one really looks to me to be numeric in nature. If it is then higher resolution would just smooth it out.
 
That is, if you are addressing the jagged edges around the top of the gif. If you are asking a question about the mode, then pardon me. Someone else will need to answer that.
SE and BE looks like TE01, the gif's show the Hz component.

@Shell: If my memory is correct the cavity was designed for TE013
That's what the view from the side at the cone looks like also.
But i understand the confusing, its the last pic in this series that make me think there is another mode in the game too.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/21/2015 05:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428233#msg1428233">Quote from: SeeShells on 09/21/2015 03:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428225#msg1428225">Quote from: rfmwguy on 09/21/2015 03:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428222#msg1428222">Quote from: Chrochne on 09/21/2015 03:06 PM</a>
Aachen EmDrive update. Just in case you missed it. Click the headline for YouTube video.
There is some music also. Check your volume first. Safety first  ;D

https://www.reddit.com/r/EmDrive/comments/3lpfpd/hackaday_emdrive_interferometer_tests_interesting/
Really like these guys going to the interferometer. My hunch is that low power and high freq will need very fine measurement resolution. They'll need Shell's International Emdrive Flight Test Facility with her vertical supports buried in tons of concrete  8)
I watched a couple times and I'm still not sure what I'm seeing, I wish he would have had a VO (no not a drink) to explain what he was doing and what the tests were trying to show.
The're heading down the right track with the test bed layout, I like it.

I'll take some pictures today after I get back from town in what I ended up with the balance beam and digital scales. I'm using the digital scales and adjusting them up and down to work with the moving fulcrum beam to be able to get a profile and cross check the accuracy of the system.
You probably thought of this, but if you weigh down the scale to the center of its range, you'll be able to see +/- changes. Have a feeling you might need to start off with no weight as the lift might take it over/under-range. Look forward to pics!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 05:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428273#msg1428273">Quote from: rfmwguy on 09/21/2015 05:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428233#msg1428233">Quote from: SeeShells on 09/21/2015 03:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428225#msg1428225">Quote from: rfmwguy on 09/21/2015 03:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428222#msg1428222">Quote from: Chrochne on 09/21/2015 03:06 PM</a>
Aachen EmDrive update. Just in case you missed it. Click the headline for YouTube video.
There is some music also. Check your volume first. Safety first  ;D

https://www.reddit.com/r/EmDrive/comments/3lpfpd/hackaday_emdrive_interferometer_tests_interesting/
Really like these guys going to the interferometer. My hunch is that low power and high freq will need very fine measurement resolution. They'll need Shell's International Emdrive Flight Test Facility with her vertical supports buried in tons of concrete  8)
I watched a couple times and I'm still not sure what I'm seeing, I wish he would have had a VO (no not a drink) to explain what he was doing and what the tests were trying to show.
The're heading down the right track with the test bed layout, I like it.

I'll take some pictures today after I get back from town in what I ended up with the balance beam and digital scales. I'm using the digital scales and adjusting them up and down to work with the moving fulcrum beam to be able to get a profile and cross check the accuracy of the system.
You probably thought of this, but if you weigh down the scale to the center of its range, you'll be able to see +/- changes. Have a feeling you might need to start off with no weight as the lift might take it over/under-range. Look forward to pics!
You're sharp rfmwguy!

My first tests will me with out the scales or even the rig supporting it, to simply to see if I get movement. You know the frustum positioned 180 in a series of increasing power to it.

The second will be a mirror of the first but using the digital scales. And yes I plan on centering the digital scales with a predetermined weight to measure ups and downs.

I've been trying to get out of here to get into town to do some shopping but phone calls and setting up some other things it seems my time is wasting, I'll still get pics....

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/21/2015 05:52 PM

Yes, to the point that commercial magnetron transmitters (say 100kW) MUST appearently have an external waterload / isolator to make sure that the reflected energy back to the magnetron is absorbed or you will damage your magnetron.

Three take aways -

1) At the smaller powers I assume there is still some reflected energy back, just not powerful enough to blow your magnetron?

2)  You unfortunately really can't build the NASA 100kW apparatus as drawn.. the good news is that you can have one big industrial magnetron and then use waveguide to feed the frustrums with your transmitter safely behind the waterload. I really don't think that design as proposed even went out to quotation so do not sit around waiting for the NASA 100kW test.

3) How does the reflected energy impact the Q-Thuster / EM-Drive effect (if real)and does it bode well for pulsing vs. continuous  (1MW pulses as opposed to 100kW continuous) for thrust? Also is this waterload going to screw up or help the tests / phenomena?


<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428016#msg1428016">Quote from: Mulletron on 09/20/2015 03:59 PM</a>
Huh, so apparently there is an initial transient of reflected power until the cavity is filled. Good to know. Starts at slide 37

http://uspas.fnal.gov/materials/08UCSC/mml06_resonant_cavities_1.pdf

That's not good for users of magnetrons featuring a duty cycle.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/21/2015 06:57 PM
Craig, I've seen mention on the net of a company that makes up to 2kw, 2.45ghz amplifiers.  If you don't already have the magnetron, perhaps a powerful amp coupled with a computer control system designed to keep the signal in tune might be better.  Less overall power, and probably less power on the resonant frequency, but I'm not sure how much less power.  Also you could nudge the power up so you don't suddenly find out that the thing wants to move sideways as well as up/down.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/21/2015 06:59 PM
"Photons that travel in free space slower than the speed of light"

http://arxiv.org/pdf/1411.3987.pdf

There are differences between plane waves and Bessel beams for the propagation constant...
Finally in free space too, really interesting i think.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/21/2015 07:31 PM

Plan is to rent an existing transmitter setup and go 100kW continuous/ (50us-pulsed+) and 1MW 10us pulsed in the ~950MHz L-Band range. Magnetron setup looks very similar to the attached unit c/w transformer, waveguide launcher/isolator, etc. Hope to be able to talk more soon and show some pictures of the unit itself. Aiming for some data above background.
My personal hope is that RS/EM-Drive is better at hitting the concept with a hammer to have gotten results showing a phenomena and that Eagleworks/Q-Thruster are better theorists that we really are dealing with magneohydrodynamics and COM with the quantum vacuum that with some juice @ mode we'll get some real thrust. If not, well, at least won't be "will it, won't it" forever.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428291#msg1428291">Quote from: SteveD on 09/21/2015 06:57 PM</a>
Craig, I've seen mention on the net of a company that makes up to 2kw, 2.45ghz amplifiers.  If you don't already have the magnetron, perhaps a powerful amp coupled with a computer control system designed to keep the signal in tune might be better.  Less overall power, and probably less power on the resonant frequency, but I'm not sure how much less power.  Also you could nudge the power up so you don't suddenly find out that the thing wants to move sideways as well as up/down.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/21/2015 07:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428303#msg1428303">Quote from: CraigPichach on 09/21/2015 07:31 PM</a>
Plan is to rent an existing transmitter setup and go 100kW continuous/ (50us-pulsed+) and 1MW 10us pulsed in the ~950MHz L-Band range. Magnetron setup looks very similar to the attached unit c/w transformer, waveguide launcher/isolator, etc. Hope to be able to talk more soon and show some pictures of the unit itself. Aiming for some data above background.
My personal hope is that RS/EM-Drive is better at hitting the concept with a hammer to have gotten results showing a phenomena and that Eagleworks/Q-Thruster are better theorists that we really are dealing with magneohydrodynamics and COM with the quantum vacuum that with some juice @ mode we'll get some real thrust. If not, well, at least won't be "will it, won't it" forever.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428291#msg1428291">Quote from: SteveD on 09/21/2015 06:57 PM</a>
Craig, I've seen mention on the net of a company that makes up to 2kw, 2.45ghz amplifiers.  If you don't already have the magnetron, perhaps a powerful amp coupled with a computer control system designed to keep the signal in tune might be better.  Less overall power, and probably less power on the resonant frequency, but I'm not sure how much less power.  Also you could nudge the power up so you don't suddenly find out that the thing wants to move sideways as well as up/down.

Please let us know down here in the States for we'll be looking for some new Northern Lights.

Good Luck with your build!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/21/2015 08:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428303#msg1428303">Quote from: CraigPichach on 09/21/2015 07:31 PM</a>
Plan is to rent an existing transmitter setup and go 100kW continuous/ (50us-pulsed+) and 1MW 10us pulsed in the ~950MHz L-Band range. Magnetron setup looks very similar to the attached unit c/w transformer, waveguide launcher/isolator, etc. Hope to be able to talk more soon and show some pictures of the unit itself. Aiming for some data above background.
My personal hope is that RS/EM-Drive is better at hitting the concept with a hammer to have gotten results showing a phenomena and that Eagleworks/Q-Thruster are better theorists that we really are dealing with magneohydrodynamics and COM with the quantum vacuum that with some juice @ mode we'll get some real thrust. If not, well, at least won't be "will it, won't it" forever.

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428291#msg1428291">Quote from: SteveD on 09/21/2015 06:57 PM</a>
Craig, I've seen mention on the net of a company that makes up to 2kw, 2.45ghz amplifiers.  If you don't already have the magnetron, perhaps a powerful amp coupled with a computer control system designed to keep the signal in tune might be better.  Less overall power, and probably less power on the resonant frequency, but I'm not sure how much less power.  Also you could nudge the power up so you don't suddenly find out that the thing wants to move sideways as well as up/down.
Whoa...best of luck. Congrats on taking the plunge fellow builder!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/21/2015 09:01 PM
geeez... 100kW continuous.... you're planning on melting some copper?  :p

You might have some serious thermal issues with that kind of power injection...

Keep in mind that Shawyer blew several magnetrons...
what if you blow that rented magnetron?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/21/2015 09:16 PM
I think this might end up with a tungsten frustum. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/21/2015 09:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428331#msg1428331">Quote from: Flyby on 09/21/2015 09:01 PM</a>
geeez... 100kW continuous.... you're planning on melting some copper?  :p

You might have some serious thermal issues with that kind of power injection...

Keep in mind that Shawyer blew several magnetrons...
what if you blow that rented magnetron?
Here's the way I look at this. If he has resonance and Q at 915 Mhz and he fires this puppy up to 100 kW, this should go a long way into proving or disproving this whole thing. Not sure how to send in 100kW with flexible cable or waveguide to where frustum movement can be detected. Look forward to the config details.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CraigPichach on 09/21/2015 10:06 PM

Yep, that is what I am working on.

So ironically for 1MW 10us, you actually can just let it air cool because test duration is so short.... but would you actually get any useful information??

For continuous it's actually an iteration with how much we can water cool (good news about the experiment is that the frustrum is far from the magnetron so we can put it in a cold water bath with constant cold water coming in at say the bottom, overfilling the hot water to a drain) and how big the frustrum can be (in turn how much power at 930MHz at a mode). With immersion cooling you have surface area ~2m2. So with say 1600W/m2 K and allowing for a 5K increase we'd actually be in good shape. Q=h * A * (T2-T1).

However it looks like this makes the unit size 70kW @ 930MHz, which is better than 5kW.. and then the 100kW will be pulsed to avoid overheat (and it looks like some think pulsing is more effective anyway).

I do want to shoot at least 70kW continuous @ ~930-950MHz at mode TE013; than a pulsed 100kW and then try the 1MW 10us. Now if we see nothing though, is it placement (easily changed with different inputs) or is it the mode (i.e. should we be TE010). Probably will have a TE010 frustrum too and then reshoot.

EDIT - Sorry, when I say continuous I mean like 30 seconds. Bad habit... This isn't continuous as in hours. In my opinion after 30 seconds you should see thrust or it isn't there.

OTHER EDIT - How will we "offset" buoyancy, answer is we won't be disregarding all "thrust" skyward and will aim for some kind of thrust value into the ground (hot air will want to rise, hot water/steam will want to rise, any value "down" will be overcoming that (wouldn't it be nice if thrust actual was higher than what was measured?). At least for the first shots.



<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428331#msg1428331">Quote from: Flyby on 09/21/2015 09:01 PM</a>
geeez... 100kW continuous.... you're planning on melting some copper?  :p

You might have some serious thermal issues with that kind of power injection...

Keep in mind that Shawyer blew several magnetrons...
what if you blow that rented magnetron?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/22/2015 12:02 AM
Fresh video from another builder:

https://www.youtube.com/watch?v=8jm4ljoNPDc
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/22/2015 01:26 AM

Just got in, sorry been out all day.

It was mode TE012 and yes it looks like TE01 and maybe another.

Shell

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428272#msg1428272">Quote from: X_RaY on 09/21/2015 05:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428160#msg1428160">Quote from: aero on 09/21/2015 05:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428157#msg1428157">Quote from: SeeShells on 09/21/2015 05:01 AM</a>
Both BE and SE

TE012?

Don't know. That one really looks to me to be numeric in nature. If it is then higher resolution would just smooth it out.
 
That is, if you are addressing the jagged edges around the top of the gif. If you are asking a question about the mode, then pardon me. Someone else will need to answer that.
SE and BE looks like TE01, the gif's show the Hz component.

@Shell: If my memory is correct the cavity was designed for TE013
That's what the view from the side at the cone looks like also.
But i understand the confusing, its the last pic in this series that make me think there is another mode in the game too.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Bob Woods on 09/22/2015 03:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428079#msg1428079">Quote from: rfmwguy on 09/20/2015 08:57 PM</a>
Spent some time today putting LDS display and DAQ module into an ancient PC. Its fast enough to datalog and also provide power to sensors. Hey, check out the cool floppy drive!

My drive has been floppy for a while. ;D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/22/2015 06:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428331#msg1428331">Quote from: Flyby on 09/21/2015 09:01 PM</a>
geeez... 100kW continuous.... you're planning on melting some copper?  :p

You might have some serious thermal issues with that kind of power injection...

Keep in mind that Shawyer blew several magnetrons...
what if you blow that rented magnetron?
yet another use for microwaves:
http://www.microwavegoldkiln.com/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/22/2015 11:50 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428293#msg1428293">Quote from: X_RaY on 09/21/2015 06:59 PM</a>
"Photons that travel in free space slower than the speed of light"

http://arxiv.org/pdf/1411.3987.pdf

There are differences between plane waves and Bessel beams for the propagation constant...
Finally in free space too, really interesting i think.

Very interesting paper.   I have been wading through the math (its been many decades LOL) but it looks like it may be of significance to the folks here.   I hope someone with better/more current math takes a look at it.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/22/2015 01:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428457#msg1428457">Quote from: graybeardsyseng on 09/22/2015 11:50 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428293#msg1428293">Quote from: X_RaY on 09/21/2015 06:59 PM</a>
"Photons that travel in free space slower than the speed of light"

http://arxiv.org/pdf/1411.3987.pdf

There are differences between plane waves and Bessel beams for the propagation constant...
Finally in free space too, really interesting i think.

Very interesting paper.   I have been wading through the math (its been many decades LOL) but it looks like it may be of significance to the folks here.   I hope someone with better/more current math takes a look at it.

Herman

Nice.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/22/2015 01:24 PM
Got in yesterday from going downtown, it was too hot... 90F and I drove my old sweetheart  a 65 Pontiac Grand Prix, no air. Got my goodies and came home to the cool mountains, posted here once, sat down to watch some news and fell asleep. :D Had every intention to get some pics of my build last night, but old age and heat had other ideas. I'll get some this morning and post them.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/22/2015 03:14 PM
Oh, how quaint...updating the old PC with windows xp service pack 3 to datalog. Pardon me while I nap before the update is completed.  >:(

One hour and counting...sheesh, how did we get by with how slow pcs were a few years ago?

One hour 20 min for sp3 install. Now it wants .net framework...zzzzzzzz
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/22/2015 04:19 PM
Glad this op ed guy wasn't around when wilbur and orville were tinkering in their garage.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: CybJaffe on 09/22/2015 04:30 PM
If EM drives offer any degree of thrust, telecommunications and science missions will benefit considerably. If it's possible to supply a lot of thrust, they'll literally change the destiny of humanity. But first, we need to know if they work or not. The theories are certainly intriguing, and there are a fair few anecdotal hints that there is something there, but as the several hundred pages of the previous thread show, figuring out what's going on is a real bear.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ElizabethGreene on 09/22/2015 05:26 PM

I'll save you the cost of buying that kit.  Silicon Carbide grinding wheels are a massive microwave sink.  Set it on a firebrick or it will seriously damage the oven.  Put a firebrick house around a crucible sitting on top of one and it will melt Aluminum.  (Haven't tried copper.)

Changing topics, how does one calculate the convective and radiative heat loss of the frustrum to the surrounding air?





<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428405#msg1428405">Quote from: Stormbringer on 09/22/2015 06:08 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428331#msg1428331">Quote from: Flyby on 09/21/2015 09:01 PM</a>
geeez... 100kW continuous.... you're planning on melting some copper?  :p

You might have some serious thermal issues with that kind of power injection...

Keep in mind that Shawyer blew several magnetrons...
what if you blow that rented magnetron?
yet another use for microwaves:
http://www.microwavegoldkiln.com/

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/22/2015 05:34 PM

Right @2,45GHz TE012 for CE-2 Rev.6. Just rechecked aero's descriptions in the share folder, and have calculated with this dimensions.  I had an older design in my mind...

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428375#msg1428375">Quote from: SeeShells on 09/22/2015 01:26 AM</a>
Just got in, sorry been out all day.

It was mode TE012 and yes it looks like TE01 and maybe another.

Shell

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428272#msg1428272">Quote from: X_RaY on 09/21/2015 05:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428160#msg1428160">Quote from: aero on 09/21/2015 05:25 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428157#msg1428157">Quote from: SeeShells on 09/21/2015 05:01 AM</a>
Both BE and SE

TE012?

Don't know. That one really looks to me to be numeric in nature. If it is then higher resolution would just smooth it out.
 
That is, if you are addressing the jagged edges around the top of the gif. If you are asking a question about the mode, then pardon me. Someone else will need to answer that.
SE and BE looks like TE01, the gif's show the Hz component.

@Shell: If my memory is correct the cavity was designed for TE013
That's what the view from the side at the cone looks like also.
But i understand the confusing, its the last pic in this series that make me think there is another mode in the game too.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/22/2015 08:18 PM
http://s1039.photobucket.com/user/shells2bells2002/library/CE%20Electromagnetic%20Reaction%20Thruster

Current build.

The other copper sheet for the CE frustum is out for water jet cutting, dropped it off yesterday. Should have it by the end of this week or first of next.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/22/2015 10:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428578#msg1428578">Quote from: SeeShells on 09/22/2015 08:18 PM</a>
http://s1039.photobucket.com/user/shells2bells2002/library/CE%20Electromagnetic%20Reaction%20Thruster

Current build.

The other copper sheet for the CE frustum is out for water jet cutting, dropped it off yesterday. Should have it by the end of this week or first of next.

Shell
I am jealous ;^)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/22/2015 11:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428625#msg1428625">Quote from: rfmwguy on 09/22/2015 10:11 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428578#msg1428578">Quote from: SeeShells on 09/22/2015 08:18 PM</a>
http://s1039.photobucket.com/user/shells2bells2002/library/CE%20Electromagnetic%20Reaction%20Thruster

Current build.

The other copper sheet for the CE frustum is out for water jet cutting, dropped it off yesterday. Should have it by the end of this week or first of next.

Shell
I am jealous ;^)

Join the crowd. There are a bunch of us.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 09/22/2015 11:19 PM
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 09/22/2015 11:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428650#msg1428650">Quote from: Mr. Peter on 09/22/2015 11:19 PM</a>
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.

If I recall correctly, these results sound consistent with Shawyer's comments regarding EM drive thrust peaking when the frequency is slightly above a cavity's calculated resonance values.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/23/2015 12:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428650#msg1428650">Quote from: Mr. Peter on 09/22/2015 11:19 PM</a>
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.

I'm not sure what exactly I'm looking at.  What is the baseline for this?  What orientation is the frustum in and is upward lift represented as the line moving up or down (for that matter what do the lines on that chart represent).  If he's showing me a report of actual downward movement, well that's interesting.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/23/2015 12:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428662#msg1428662">Quote from: SteveD on 09/23/2015 12:14 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428650#msg1428650">Quote from: Mr. Peter on 09/22/2015 11:19 PM</a>
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.

I'm not sure what exactly I'm looking at.  What is the baseline for this?  What orientation is the frustum in and is upward lift represented as the line moving up or down (for that matter what do the lines on that chart represent).  If he's showing me a report of actual downward movement, well that's interesting.

Maybe these are good results, but we definitely need some more context. I would like to see some duration of baseline without any power to see if there is an inherent drift. What is the interferometer measuring and what are the units? 

Is he still using the levitating magnetic table and changing the speed of rotation?

I don't recall anyone saying that thrust maximizes slightly above the calculated resonant frequency (but I could definitely be wrong). Could this be due to slight thermal expansion?

by the way: build is looking great Shell! have you tried the power inverter on the magnetron? if so, do you know what effect it had?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 01:35 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428667#msg1428667">Quote from: zellerium on 09/23/2015 12:28 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428662#msg1428662">Quote from: SteveD on 09/23/2015 12:14 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428650#msg1428650">Quote from: Mr. Peter on 09/22/2015 11:19 PM</a>
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.

I'm not sure what exactly I'm looking at.  What is the baseline for this?  What orientation is the frustum in and is upward lift represented as the line moving up or down (for that matter what do the lines on that chart represent).  If he's showing me a report of actual downward movement, well that's interesting.

Maybe these are good results, but we definitely need some more context. I would like to see some duration of baseline without any power to see if there is an inherent drift. What is the interferometer measuring and what are the units? 

Is he still using the levitating magnetic table and changing the speed of rotation?

I don't recall anyone saying that thrust maximizes slightly above the calculated resonant frequency (but I could definitely be wrong). Could this be due to slight thermal expansion?

by the way: build is looking great Shell! have you tried the power inverter on the magnetron? if so, do you know what effect it had?

Not yet, I just got in the new inverter and I still need to build a 555 timer to set the on and power plus set up a microwave oven to dump it into to just test.  I like the 33KHz switching idea providing variable power.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 01:41 AM
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/23/2015 02:11 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428687#msg1428687">Quote from: SeeShells on 09/23/2015 01:41 AM</a>
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.

Please correct me if I'm wrong, but I don't remember Maxwell's equations accounting for tunneling...
What other mechanism could lead the program to calculate a non-zero field outside of the frustum?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 02:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428692#msg1428692">Quote from: zellerium on 09/23/2015 02:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428687#msg1428687">Quote from: SeeShells on 09/23/2015 01:41 AM</a>
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.

Please correct me if I'm wrong, but I don't remember Maxwell's equations accounting for tunneling...
What other mechanism could lead the program to calculate a non-zero field outside of the frustum?
You're quite right Maxwell's equations don't. What we are seeing on the picture on the left is inside of the frustum,  maybe evanescent waves at the corners around the outside,  or it simply could be an artifact.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/23/2015 03:23 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428693#msg1428693">Quote from: SeeShells on 09/23/2015 02:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428692#msg1428692">Quote from: zellerium on 09/23/2015 02:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428687#msg1428687">Quote from: SeeShells on 09/23/2015 01:41 AM</a>
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.

Please correct me if I'm wrong, but I don't remember Maxwell's equations accounting for tunneling...
What other mechanism could lead the program to calculate a non-zero field outside of the frustum?
You're quite right Maxwell's equations don't. What we are seeing on the picture on the left is inside of the frustum,  maybe evanescent waves at the corners around the outside,  or it simply could be an artifact.

My guess is artifact.
I haven't seen anything like it in EMPro, but I'll keep an eye out.


I'm having second thoughts about switching to an amplifier, maybe you all can help me make a decision.
It seems the biggest benefit of using an amplifier system would be difficulty. It is just a matter of borrowing a signal generator and buying the parts: isolator, coax, and a waveguide to coax, and vacuum chamber feed thru.  Then we manufacture a frustum either by bending our sheet metal or sand casting and using a CNC to clean it up. Weld an adapter to the frustum and fit an aperture on it, and presto.

The con is the expected result. Linearly extending NASA's TE012 test (their highest efficiency), we would expect ~4 mN at 200 W.  This is barely in our detectable threshold, although our resolution should get better in the vacuum chamber. How much better I'm not sure... We could rent a 500 W amp for a month, but there's the added complication of a required dielectric which might have greater losses at higher power. Someone mentioned that a solid state amp could be rapidly switch on/off to mimic a duty cycle, but what about the phase/amplitude modulation? I'd say best case scenario we achieve a thrust to power equal to NASA.


On the other hand, a magnetron system would be higher power, and would remove the need for a dielectric. We buy a better magnetron with more stability and maybe higher power, a circulator, 2 waveguides to coax , a matched load, and a vac chamber feed thru. 
I think the biggest problem is a tunable mechanism. Maybe we could buy a short circuit plunger and attach that to one side of the frustum? I haven't simulated it yet but might be worth a shot.

The expected results would be 100-700 mN, well within our resolution and much more definitive evidence. 

Option A: Simpler, more controllable, low expected thrust.
Option B: More complicated, less controllable, high expected thrust, more questions to answer.

But now school is in the way, and I'm set on graduating this year. Maybe we could make this happen by June, or maybe this experiment should be saved as a master's thesis. We've got a month to finish our proposal, and free time is dwindling...

Any thoughts?

Kurt

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/23/2015 03:55 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428706#msg1428706">Quote from: zellerium on 09/23/2015 03:23 AM</a>
Any thoughts?

Kurt

Build a simple copper frustum & drive it the way you intend but adopted to allow rtn loss scans to be done. Vary the frustum dimensions & Rf drive system until you have resonance in your desired mode plus acceptable VSWR. That way you build from a solid base.

THEN go for Force generation measurements.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 04:44 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428706#msg1428706">Quote from: zellerium on 09/23/2015 03:23 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428693#msg1428693">Quote from: SeeShells on 09/23/2015 02:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428692#msg1428692">Quote from: zellerium on 09/23/2015 02:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428687#msg1428687">Quote from: SeeShells on 09/23/2015 01:41 AM</a>
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.

Please correct me if I'm wrong, but I don't remember Maxwell's equations accounting for tunneling...
What other mechanism could lead the program to calculate a non-zero field outside of the frustum?
You're quite right Maxwell's equations don't. What we are seeing on the picture on the left is inside of the frustum,  maybe evanescent waves at the corners around the outside,  or it simply could be an artifact.

My guess is artifact.
I haven't seen anything like it in EMPro, but I'll keep an eye out.


I'm having second thoughts about switching to an amplifier, maybe you all can help me make a decision.
It seems the biggest benefit of using an amplifier system would be difficulty. It is just a matter of borrowing a signal generator and buying the parts: isolator, coax, and a waveguide to coax, and vacuum chamber feed thru.  Then we manufacture a frustum either by bending our sheet metal or sand casting and using a CNC to clean it up. Weld an adapter to the frustum and fit an aperture on it, and presto.

The con is the expected result. Linearly extending NASA's TE012 test (their highest efficiency), we would expect ~4 mN at 200 W.  This is barely in our detectable threshold, although our resolution should get better in the vacuum chamber. How much better I'm not sure... We could rent a 500 W amp for a month, but there's the added complication of a required dielectric which might have greater losses at higher power. Someone mentioned that a solid state amp could be rapidly switch on/off to mimic a duty cycle, but what about the phase/amplitude modulation? I'd say best case scenario we achieve a thrust to power equal to NASA.


On the other hand, a magnetron system would be higher power, and would remove the need for a dielectric. We buy a better magnetron with more stability and maybe higher power, a circulator, 2 waveguides to coax , a matched load, and a vac chamber feed thru. 
I think the biggest problem is a tunable mechanism. Maybe we could buy a short circuit plunger and attach that to one side of the frustum? I haven't simulated it yet but might be worth a shot.

The expected results would be 100-700 mN, well within our resolution and much more definitive evidence. 

Option A: Simpler, more controllable, low expected thrust.
Option B: More complicated, less controllable, high expected thrust, more questions to answer.

But now school is in the way, and I'm set on graduating this year. Maybe we could make this happen by June, or maybe this experiment should be saved as a master's thesis. We've got a month to finish our proposal, and free time is dwindling...

Any thoughts?

Kurt
The bottom line is this is your build and what you decide given your resources is what you should do. All I can do is tell you why I went the direction I did and maybe it will help in your decision.

Nobody has figured out just what it is that causes the thrust that we know of but, when I looked at all the tests a couple of things stood out. One was the TE012 mode, while tough to get it seems it seemed to provide the best thrust reading from all the tests. Even considering the issues of thermal deformations and heat ballooning that came with high power it seemed to me to be a obvious course to take.

The second thing that evolved after multiple tests with meep and here aero did a great job guided by Dr. Rodel and me just throwing out idiot drivel thoughts and ideas. It became obvious the antenna placement was one of the most critical issues that seemed not to be fully addressed by The Chinese or EW or even RS or even Dresden. I came to the conclusion that a symmetrical injection into the sections that  the modes developed in was the best course to take.

I wanted to go to high power but I also wanted to control two things. One was the thermal expansion issue of the frustum's walls and second was to be able to stay in resonance. To make that feat happen I would need a tuneable RF source and it would have to be something better than 40 watts into the frustum. That became pricey with amp. So I decided to find a way to keep tune and allow the frustum to deform without changing the distance between the end plates. I had a flash that I could use a quartz rod connecting the two that would allow tuning and also the side walls to move past the small end plate as it heated. This would give me the ability to pre-tune using a VNA and go to high power and remain in resonance.

The issues remained that a standard power supply for the magnetron was less than ideal and would have much of it's power dissipated in non-resonating frequencies. I tried to modify a standard magnetron power supply in modifying it's 50% duty cycle to 100% and stabilize the output and they (2x) failed with a techie phhhfffttt.  Found a inverter power supply would work well and I would have power and a stabilized output. I think I could achieve up to 2KW out from this inverter design but I plan on taking it slow to ramp it up as it's unknown territory.

I have currently two designs, the first will be multi-modified loops in the small plate and the second will be opposing waveguides into the frustum by coaxial feeds. I'm going to be building these waveguides and have ordered the aluminum rectangular tubes to do it. With both designs I'll be controlling the symmetry of the inserted RF and simply letting the Frustum's shape do what it does because it's the shape that defines if there is to be any thrust...IMHO

Points I had to work with...

Control the power and make sure it's clean and stable
Control the resonance by mechanical means
Control the thermal expansion and negate it by design
Inject the RF symmetrically into the frustum to develop clean mode(s)

This is a summary of what I did and why. The test bed I wanted to be able to do both acceleration of the fulcrum beam and measure the pressures and do it in several orientations. Plus record as much data as I can. I'll be honest it has been fun but, a lot of work to make sure it works as designed although that's where the rubber will hit the road.

I sure hope this summary helps.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/23/2015 05:10 AM
NSF-1701 update -

Whew...full day. Computer update took hours. Successfully connected it to LDS. Powered up frustum and learned quite a lot:

1. Resolution is easily below 20 mg with 3 micrometer accuracy, 0.15 msec LDS sample rate and DAQ at 5 msec with oscilloscope display on PC!
2. Docs oil dampener is fantastic, oscillations dampen within a minute. Amazing with a 7 foot balance beam.
3. Fired up mag for 2 test runs at 30% power cycle and a minute each. Each run was monitored but not recorded as LDS and DAQ were being evaluated.
4. Thermal lift was startling. Within about 15 secs, lift took frustum up to max range of LDS, or 10 mm.
5. Both fire-ups showed what looked like a momentary attempt (a second or two) to move opposite of lift. I cannot say for certain, but it appears thrust is trying to form. It is not sustainable and lift quickly takes over. I will button everything up and video this soon. Too early to say for sure.
6. Lift characteristics are very odd with pauses and minor oscillations. There is no evidence of the fulcrum sticking or jumping.
7. Lift continues to increase even after 1 minute cycle is completed! This I find fascinating. Believe it is a heat chimney effect that builds as air currents become more organized and heat disperses from the magnetron core outwards. Every builder will need to plan for this, especially higher power units.
8. There was no evidence of RFI in any of the equipment. Distance between frustum and gear over 6 feet.
9. The max lift value persists for nearly 5 minutes then very slowly begins to return to the starting position. Easily 15 to 20 minutes.

That's about it for now...long day. Will tidy up the setup and record firm data later in the week. Bottom line, happy with LDS, DAQ and PC. Glimmer of hope regarding movement against lift. Slow dissipation of lift likely means ideal test run is not from a cold start but only after mag and frustum are stabilized at max temp.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 09/23/2015 07:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428650#msg1428650">Quote from: Mr. Peter on 09/22/2015 11:19 PM</a>
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.
Apparently there is no dielectric  inside the cavity.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/23/2015 10:47 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428655#msg1428655">Quote from: RotoSequence on 09/22/2015 11:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428650#msg1428650">Quote from: Mr. Peter on 09/22/2015 11:19 PM</a>
Guys, have you seen this?
https://hackaday.io/project/5596/log/25759-got-something
Looks like Paul's got something.

If I recall correctly, these results sound consistent with Shawyer's comments regarding EM drive thrust peaking when the frequency is slightly above a cavity's calculated resonance values.

In all honesty, i have a hard time seeing any consistent correlation between the different graphs.
I'm not yet prepared to shoot it out of the air, but as it currently stands, as ignorant outsider, i don't see anything...
Maybe it needs more post-processing to make it more readable?

I suppose there is no need to warn about "voluntarism", where people are seeing things because they so badly want it to happen?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 03:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428692#msg1428692">Quote from: zellerium on 09/23/2015 02:11 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428687#msg1428687">Quote from: SeeShells on 09/23/2015 01:41 AM</a>
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.

Please correct me if I'm wrong, but I don't remember Maxwell's equations accounting for tunneling...
What other mechanism could lead the program to calculate a non-zero field outside of the frustum?

I'm not talking about QT but what I don't understand and maybe you or someone here can help me understand what I'm seeing. Both images are the same size. The 2 horizontal black lines defines the inner copper boundary I believe. On the left image I can understand the why the frequency of the harmonic mode cannot squeeze into the bottom corner between the sidewall and the bottom plate but on the right it does. What am I missing here? How can it?

For those meepers out there do you know of a way you can make the boundary walls visible during a run?

Maybe I need another cup of coffee?

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/23/2015 03:48 PM



One of the graphs is a null test.  Are you talking about the raw data from the laser?  I worry that I don't know the baseline, am only assuming that down on the graph is downward thrust, don't see a graph with feed off to help characterize the noise in the system and don't know what physicsl units the output corresponds to.   Too bad we can't get it on one if shells vibration dampened tables.  Even then, the measuring device might be so sensitive that heat from the RF source is causing lift that is then being transmited as a downward force on the rf feed line that is levering the device downward.

Needs a vacuum test.

Quote
I'm not yet prepared to shoot it out of the air, but as it currently stands, as ignorant outsider, i don't see anything...
Maybe it needs more post-processing to make it more readable?

I suppose there is no need to warn about "voluntarism", where people are seeing things because they so badly want it to happen?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/23/2015 04:43 PM
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 05:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428840#msg1428840">Quote from: rfmwguy on 09/23/2015 04:43 PM</a>
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...

Just because you put your frustum into a vacuum it still means you have thermal issues. Your frustum can't rid itself of heat like it would do in ambient air and would deform from the build up. Many think that a vacuum is a solution to the buoyancy issues but it opens up another set of heating issues within the frustum itself.

I think the way you're doing it is one of the best for a DYIer. Your outside connecting rods on the top and bottom plate were very smart to keep your distances between the plates stable, so really you just have to figure out a way to log the thermal data to subtract from the possible thrust effects or keep your maggie cool.

This is a hair brained idea but the issue is the vertical component from the rising heated air creating pressure differentials between the top and bottom of your frustum... right?
If you add a rotational competent to your frustum movement but remove the thermal rising pressure differential it could reduce the issues you see in your vertical measurements.

You could log the effects from the fans maybe a little easier than the chaotic dance of thermal currents.

Ok no laughing... ;)

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/23/2015 05:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428840#msg1428840">Quote from: rfmwguy on 09/23/2015 04:43 PM</a>
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...

Was thinking of the mini-EMDrive that might fit into a small vacuum chamber (though I wonder if the electronics involved can run in vacuum).  The forces there are small enough that they're using a laser interferometer to measure it.

For NSF-1701, I think the strange behavior of the lift might be related to air escaping from around the magnetron heatsink at random intervals.  That said, I keep going back to that quantum reflection of photons paper.  There were some mentions of redshift (not surprising, bouncing around photons should produce redshift).  I wonder if I'm misunderstanding and some redshift is the result of the quantum mirror "powering up" and starting to reflect photons before resonance is reached.  That would explain why peak thrust is reached at a frequency slightly higher than the resonant frequency of the frustum -- the waves are being redshifted down into the resonant frequency.

Extending on the idea of some type of quantum mirror, it strikes me that photons being released from heat could become involved.  (Especially if the mirroring isn't some prism sitting out in space but taking place within nanometers of the surface.)  Reflection of IR photons back on the surface from which they came would seem like it should have an insulating effect.  It strikes me that the rate at which copper sheds heat should be quantifiable.  You could measure the rate at which heat dissipates from the frustum after power off.  If its being shed too slowly then there is an argument for an interesting thermal effect that persists for some time after shutdown (explaining why Tajmar reports an unknown thrust of an apparently thermal nature in a vacuum chamber; it is a thermal effect and it's causing real thrust).  At worst you'll end up with more data to help characterize the thermal lift.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/23/2015 06:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428687#msg1428687">Quote from: SeeShells on 09/23/2015 01:41 AM</a>
Yesterday aero re-ran the Yang Shell 6 degree frustum and we saw some artifacts that got me wondering if they were on the inside or outside. The image is of the large plate comparing 2 different modes but same size in meep. I drew a line across the two to see if if could give me a clue if the unusual artifact was in the copper boundary walls.

I superimposed one image over the other in gimp.  Hopefully the resolution is low enough that I was able to line up pixels effectively.  It looks like those nodules are on the inside of the frustum (though doing a MEEP run with an airbox outside of the frustum might still be useful to confirm).

Edit - that pattern is just a result of me setting transparency on the layer, right?  It's never going to actually look like that, we are not creating a circular non-homogeneous magnetic field on the large base, are we?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/23/2015 06:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428868#msg1428868">Quote from: SteveD on 09/23/2015 05:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428840#msg1428840">Quote from: rfmwguy on 09/23/2015 04:43 PM</a>
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...

Was thinking of the mini-EMDrive that might fit into a small vacuum chamber (though I wonder if the electronics involved can run in vacuum).  The forces there are small enough that they're using a laser interferometer to measure it.

For NSF-1701, I think the strange behavior of the lift might be related to air escaping from around the magnetron heatsink at random intervals.  That said, I keep going back to that quantum reflection of photons paper.  There were some mentions of redshift (not surprising, bouncing around photons should produce redshift).  I wonder if I'm misunderstanding and some redshift is the result of the quantum mirror "powering up" and starting to reflect photons before resonance is reached.  That would explain why peak thrust is reached at a frequency slightly higher than the resonant frequency of the frustum -- the waves are being redshifted down into the resonant frequency.

...  At worst you'll end up with more data to help characterize the thermal lift.

Thats my hope. When I report the thermal "settling" time after power off, think people will be surprised at the persistence. It was late last night. Had no idea it would go in for minutes. This probably tells me heating below the magnetron has stopped after power-off and the persistence is from the mag shedding heat very slowly. Not to mention lift continued upwards after power-off. However, I can't claim this to be a fact yet, its just unexpected.

As far as fans are concerned Shell, I'm gonna try and avoid any shawyer-like pumps and fans, although I might try and blow air across it perpendicular to rise.  ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/23/2015 06:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428883#msg1428883">Quote from: rfmwguy on 09/23/2015 06:28 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428868#msg1428868">Quote from: SteveD on 09/23/2015 05:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428840#msg1428840">Quote from: rfmwguy on 09/23/2015 04:43 PM</a>
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...

Was thinking of the mini-EMDrive that might fit into a small vacuum chamber (though I wonder if the electronics involved can run in vacuum).  The forces there are small enough that they're using a laser interferometer to measure it.

For NSF-1701, I think the strange behavior of the lift might be related to air escaping from around the magnetron heatsink at random intervals.  That said, I keep going back to that quantum reflection of photons paper.  There were some mentions of redshift (not surprising, bouncing around photons should produce redshift).  I wonder if I'm misunderstanding and some redshift is the result of the quantum mirror "powering up" and starting to reflect photons before resonance is reached.  That would explain why peak thrust is reached at a frequency slightly higher than the resonant frequency of the frustum -- the waves are being redshifted down into the resonant frequency.

...  At worst you'll end up with more data to help characterize the thermal lift.

Thats my hope. When I report the thermal "settling" time after power off, think people will be surprised at the persistence. It was late last night. Had no idea it would go in for minutes. This probably tells me heating below the magnetron has stopped after power-off and the persistence is from the mag shedding heat very slowly. Not to mention lift continued upwards after power-off. However, I can't claim this to be a fact yet, its just unexpected.

As far as fans are concerned Shell, I'm gonna try and avoid any shawyer-like pumps and fans, although I might try and blow air across it perpendicular to rise.  ;)
I see what your saying on the RS pumps and fans but his were not strategically placed and he didn't quantify them. Even placing a air flow over the top, the maggie will still create a thermal pressure high and low that will draw the frustum upwards.

I thought it world be a interesting way to turn a vertical thermal chaotic effect into a easier quantifiable rotational one and rid the upwards rising thermal plume from your maggie. In other words turn your vertical rising component into a rotational which your measurements can't see anyway. Am I just blowing hot air here? :D

It would be easy to test with a couple of PC fans to see the difference in vertical measurements.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 09/23/2015 07:21 PM
Unless Aero has changed something recently, all the MEEP simulations have air or vacuum inside and outside the copper walls.  Radiation could be seen propagating outside the frustum if there were any.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/23/2015 07:37 PM
Rfmwguy -

If thermal effects operated on a timescale much longer than thrust effects, you could proceed as follows.

Cycle the magnetron on/off quite quickly, but for a long time. If the cycle time is much shorter than the response time for thermal effects, you should reach a situation where the system is always close to constant thermal effect, but with a superimposed cyclical thrust. It would be easy to pick out the corresponding cyclical component in the response. If that cyclical signal reverses when you invert the frustrum, you would have some evidence for thrust.

One fly in the ointment might be that the response time for the beam is too long to allow the rapid magnetron cycling to be seen. The method would only work if the cycle time and beam and thermal response times all fit right. At the very least you would have to pick the cycle time judiciously, and then get a little lucky with the thermal inertia.

No originality from me here, this is more or less what you did on your first test, though the cycling then was more to do with thermal management than creating a signal to extract.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/23/2015 07:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428912#msg1428912">Quote from: RERT on 09/23/2015 07:37 PM</a>
Rfmwguy -

If thermal effects operated on a timescale much longer than thrust effects, you could proceed as follows.

Cycle the magnetron on/off quite quickly, but for a long time. If the cycle time is much shorter than the response time for thermal effects, you should reach a situation where the system is always close to constant thermal effect, but with a superimposed cyclical thrust. It would be easy to pick out the corresponding cyclical component in the response. If that cyclical signal reverses when you invert the frustrum, you would have some evidence for thrust.

One fly in the ointment might be that the response time for the beam is too long to allow the rapid magnetron cycling to be seen. The method would only work if the cycle time and beam and thermal response times all fit right. At the very least you would have to pick the cycle time judiciously, and then get a little lucky with the thermal inertia.

No originality from me here, this is more or less what you did on your first test, though the cycling then was more to do with thermal management than creating a signal to extract.

R.
Thanks, very good thoughts. You are right, I did the 30% for 5 minute testing and it brought the mag up to temp and maintained it around 170 deg C. The beam actually starts rising fairly quickly. This surprised me since I have a 4x4 inch, 3 inch deep oil pool for the dampener.

I did use a stainless shower drain cover (no, my wife said I had to buy one) which has many rectangular holes allowing oil flow. I had a solid circular piece at one time and it retarded movement way too much.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 09/23/2015 09:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428840#msg1428840">Quote from: rfmwguy on 09/23/2015 04:43 PM</a>
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...

Congratulations on the continued characterization work!

Perhaps another optimization to consider is what modifications to the magnetron housing might improve passive heat dissipation?  Various Intel CPU heatsinks and such have been mentioned in the past;  I wonder if affixing some thermal grease and some extra heatsink fins (copper preferably, rather than aluminum) would help heat dissipation?

Pictures of your magnetron seem to suggest ?aluminum? heat sink fins....   compared to the aggressive copper fin counts available in modern CPU and chipset heatsinks, I suspect there's some low-hanging fruit available.  Also seems like that magnetron was designed to be mounted with those straight heatsink fins oriented vertically (perhaps to allow a chimney effect to improve passive cooling?).  I suspect the magnetron heatsink fins won't be nearly as effective when oriented horizontally and stacked on top of each other.

https://www.youtube.com/watch?v=QFPTQMX8R0I (https://www.youtube.com/watch?v=QFPTQMX8R0I)

P.S.  Caution regarding potential hazardous substances within the magnetron/housing should probably be restated for the benefit of lurkers.  Drilling holes into a magnetron is *NOT* recommended;  the resulting air-born powders can be very dangerous.  Instead, I was envisioning use of thermal grease and securing with cable clamps/ties and/or some high-temp RTV in the corners.

EDIT: fixed NSF-1701 youtube video link
EDIT: +Caution against drilling into a magnetron

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/23/2015 09:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428905#msg1428905">Quote from: lmbfan on 09/23/2015 07:21 PM</a>
Unless Aero has changed something recently, all the MEEP simulations have air or vacuum inside and outside the copper walls.  Radiation could be seen propagating outside the frustum if there were any.

I've been running air filled frustums lately - can't remember when the last time I ran vacuum filled but these runs are most assuredly air filled.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/23/2015 09:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428940#msg1428940">Quote from: jmossman on 09/23/2015 09:08 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428840#msg1428840">Quote from: rfmwguy on 09/23/2015 04:43 PM</a>
I'm going to do everything I can to design the test in ambient air. I know its not the best, but for DIY types, vac chambers, especially large ones, are a no go. Working on a plan to negate lift but only running the tests at a preheated temp. Whether thats a heater underneath or fire the magnetron up for warm-up has not been decided.

Regardless, my goal is to beat the lift characteristics which I think can be quantified and removed from the test data. Thats my hope anyway...

Congratulations on the continued characterization work!

Perhaps another optimization to consider is what modifications to the magnetron housing might improve passive heat dissipation?  Various Intel CPU heatsinks and such have been mentioned in the past;  I wonder if affixing some thermal grease and some extra heatsink fins (copper preferably, rather than aluminum) would help heat dissipation?

Pictures of your magnetron seem to suggest ?aluminum? heat sink fins....   compared to the aggressive copper fin counts available in modern CPU and chipset heatsinks, I suspect there's some low-hanging fruit available.  Also seems like that magnetron was designed to be mounted with those straight heatsink fins oriented vertically (perhaps to allow a chimney effect to improve passive cooling?).  I suspect the magnetron heatsink fins won't be nearly as effective when oriented horizontally and stacked on top of each other.

https://www.youtube.com/watch?v=QFPTQMX8R0I (https://www.youtube.com/watch?v=QFPTQMX8R0I)

P.S.  Caution regarding potential hazardous substances within the magnetron/housing should probably be restated for the benefit of lurkers.  Drilling holes into a magnetron is *NOT* recommended;  the resulting air-born powders can be very dangerous.  Instead, I was envisioning use of thermal grease and securing with cable clamps/ties and/or some high-temp RTV in the corners.

EDIT: fixed NSF-1701 youtube video link
EDIT: +Caution against drilling into a magnetron
Thanks! Yep, Berrylium Oxide ceramic is nasty stuff...not drilling or fiddling about with it.

Good observation. I did notice the fins (yokes) were aligned vertically in the microwave box just as you suspected. This would make a better chimney for sure, but not possible with my config.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aceshigh on 09/24/2015 05:59 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428956#msg1428956">Quote from: rfmwguy on 09/23/2015 09:59 PM</a>
Thanks! Yep, Berrylium Oxide ceramic is nasty stuff...not drilling or fiddling about with it.


plus thorium mixed with tungsten... (in the filament)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 09/24/2015 06:20 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1428956#msg1428956">Quote from: rfmwguy on 09/23/2015 09:59 PM</a>
Good observation. I did notice the fins (yokes) were aligned vertically in the microwave box just as you suspected. This would make a better chimney for sure, but not possible with my config.

You could spring for a 90 degree waveguide and position the magnetron closer to the fulcrum, but I have no idea what that would do to your weight (or fiscal) budget.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Fugudaddy on 09/24/2015 03:25 PM
Okay so this may well be a wrong-headed idea, but what is the reason for using a solid tube attached to the side of the frustum to deliver EM energy? If the main cause for lift is the heat generated by the EM generator (such as in nsf-1701), then if that is instead connected to the main frustum via something with some 'give' to it, it may not deliver as 'clean' of microwaves (if that matters), but it should then eliminate thermal lift caused by the EM generation system. No?
Ronald
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: madmax on 09/24/2015 03:55 PM
Ronald, until you asked this, I think I had assumed (perhaps wrongly) that the heating that was interfering with measurement was the frustrum. But if it's the magnetron only that is heating, couldn't that be isolated from the frustrum / measurement apparatus?

Or is there heating of the frustrum as well?



Been lurking for quite a while, but decided to make an account when I saw this. :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/24/2015 04:46 PM
NSF-1701 update - tonight, I will record and upload video of Flight Test 2A. It will be a long one, will do a walkaround of upgraded test stand, the flight test itself and a screen capture of the data, so I'll keep the video rolling then add the screen capture video at the end. Let me say this...I spent the morning live testing and determined how to stabilize lift, it is a magnetron preheat to 170 degrees C. Stay tuned, you will not be disappointed. My results will be posted on NSF first.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/24/2015 11:07 PM
Areo and I got the dual opposing waveguides working, wasn't sure what we would see but I hoped for a symmetrical mode generation and there was. Taking a slices of time through the CE  frustum it is apparent that there are at least 2 modes overlaying each other.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 09/25/2015 12:35 AM

Quote
Areo and I got the dual opposing waveguides working, wasn't sure what we would see but I hoped for a symmetrical mode generation and there was. Taking a slices of time through the CE  frustum it is apparent that there are at least 2 modes overlaying each other.

Going from the overly colorful image...

...'forward' thrust being dispersed 'sideways' instead of bouncing clear to the opposite end of the frustum?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:08 AM
NSF-1701 Update - Below is the walkaround I did this afternoon on the improved test stand in preparation for Flight Test 2B tonight. Only glitch I have is the old, slow PC just can't handle screen recording software without pushing the lame microprocessor to max...rather than re-doing the computer (it works fine for data logging) I will simply record the video monitor. I will also record the data in the software and will make it available as a separate attachment. So here you go, the results of 3 months of building to get to this point. New test stand walkaround:

https://youtu.be/l241ecg6K3k

Flight Test 2B coming later tonight.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:54 AM
NSF-1701 Update - I have just finished Flight Test 2B at 9:45 PM EST September 24th, 2015 and am uploading the video now. While I was not able to screen capture due to a slow computer, I taped the video monitor and recorded the serial data which I will make available as an attachment soon. I would like to tell you the results now, but I think you should watch the video as the results unfold. I'll post the video link here after the upload...about 90 minutes from now. I am prepared to draw a conclusion about my Electromagnetic Engine Experiment. Some may like it, some may not. Get ready for either.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 04:04 AM
Recent email corro with Roger Shawyer.

There is a lot of real engineering information and solid answers in this exchange.

The difference between the loaded and unloaded Q Roger has shared with an ideal injection match is new information and is why I believe SPR are now doing pulsed injection as after the Rf injection period is over (and the associated injection caused phase distortion) the cavity is them able to form a non phase distorted resonant condition, doubling the cavity Q (going from loaded Q to unloaded Q) and Force generation.

Roger makes this clear in his statement about the Flight Thruster and how the Force generated matches the doubled unloaded Q and not the 1/2 lower loaded, Rf injection period Q.

So as Roger explains in his latest patent application, the main Force is generated AFTER the Rf injection is switched off. Why? Because after the Rf pulse stops, the cavity Q doubles as it can now operate in an unloaded mode.

Nice breadcrumbs Roger. You have answered a lot of my questions.

Thanks.

> Hi Roger,
>
> I'm home again, recovering from the effects of the super bug I picked up in
> hospital. Have a deep wound, caused by the super bug, where one of the
> robot arms entered by abdomen. Like a 2nd belly button. Docs want me to
> take it very gentle until it starts to naturally regrow. They don't want to
> close it up just yet, just to be sure to not close with some of the
> superbug bacteria still active inside. So for now I have a patch over my
> 2nd belly button and daily nurse visits.
>
> So some time before I'm allowed in my workshop. But not wasting the time.
>
> Most of the software for the Raspberry PI 2B based control & monitoring
> system has been written. Will have a high power 5GHz WiFi based USB
> connection for control & data logging from the rotary table to my laptop.
>
> Point of discussion with others, NSF and myself. How do you / SPR measure
> frustum bandwidth / Q? Do you use bandwidth at 3dB away from max S11 rtn
> loss dB freq (as Prof Yang does) or 3dBs from 0 dB ref level as
> Eagleworks / NSF do or do you guys use another method? Would prefer to
> measure Q as you guys do. Makes a massive difference in bandwidth, Q &
> projected Force generation.

> Hi TT
>
> Using a network analyser to determine the Q of a high Q cavity via S11 is
> quick but requires a good understanding of the effect of scan speed and
> detector bandwidth or the results can be wildly inaccurate.
>
> For the delivery data of space qualified equipment, a calibrated procedure
> using separate signal source and power meter was usually specified. This is
> the technique we have always used at SPR.
>
> The signal source is put on a slow sweep to allow a dwell time of at least
> 10X time constant at each measurement point. The internal cavity power is
> measured using a cavity wall mounted detector measuring at least 30dB down
> (a very short probe!) and a wide detection bandwidth. The data is processed
> to measure the bandwidth 3dB down from max power level for at least two
> scans, one in each direction. (they must agree or there is a drift error in
> the measurement).
>
> Hope this helps.
>
> Best regards
>
> Roger

> Hi Roger,
>
> Thanks.
>
> So you prefer 2 port S21 over 1 port S11 or is S11 ok if the scan speed is
> VERY slow?
>
> I do understand the need for a SLOW scan and the frustum fill time / TC
> factor. What you shared is in line with my understanding.
>
> May I share this information on NSF cause there are a few arm chair
> "experts" that are strongly saying to measure bandwidth 3dB from the rtn
> loss 0dB reference level, which to me is madness.

> Hi TT
>
> S11 measurements are complicated if a highly tuned input circuit is used. I have seen published measurements that are clearly the Q of the input circuit only.
>
> Note that all Q measurements are Loaded Q measurements, and strictly speaking, if a perfect match is achieved, the actual unloaded Q is twice the measured Q.
>
> There are endless papers on the complications of Q measurement which is why smart customers are very careful about deliverable test data.
>
> The thrust predicted by the Thrust equation assumes unloaded Q. The measured thrust for the Flight thruster was very close to the predicted thrust when twice the measured Q was used in the equation.
>
> The design was successfully sold to Boeing on the measured thrust data.
>
> Feel free to share my comments on your forum.
>
> Best regards
>
> Roger
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 05:02 AM
NSF-1701 Update - Flight Test 2B is now available to view. The results speak for themselves. I uploaded raw, unedited camcorder video right from the camera. Nothing was done to it. Some might want to download it and enhance it for better viewing on your PC.

Here's where I want to say that I thank everyone who has given me positive support and critiques along the way. Special thanks to Doc Rodal and Chris Bergen for providing this forum which has been an invaluable resource. Thanks to all my fellow builders for never giving up hope.

But enough with my late night ramblings, see the video and evidence for yourself. It is completely uploaded in HD and is now ready to view:

https://youtu.be/HPm2oPUPi2Q
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 05:52 AM
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 06:04 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)

Congratulations on your good work.

Elimination of thermal lift is, as you have so clearly shown, of high importance, to improve the signal to noise ratio of the Force generation signal.

Makes the EW atmo measured EMDrive Force signatures highly significant, where they also had thermal issues to deal with.

I'm sure Iulian will enjoy seeing your data as his data is comparable. Attached is the scale force I observed from his upward Force video. It is clear there is thermal lift but it is also clear as the power is switch off, how quickly his Force dropped, which you also observed.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/25/2015 06:12 AM
Do I calculate that correctly, 18 mg ~ 176 micro-Newtons?

It looked like force to me, but that is a pretty small number compared even to the EW and Tajmar results.

But it looks like force, so from here we are miles ahead of where we were yesterday.

Congratulations rfmwguy, job well done and just getting started!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 06:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429461#msg1429461">Quote from: aero on 09/25/2015 06:12 AM</a>
Do I calculate that correctly, 18 mg ~ 176 micro-Newtons?

It looked like force to me, but that is a pretty small number compared even to the EW and Tajmar results.

But it looks like force, so from here we are miles ahead of where we were yesterday.

Congratulations rfmwguy, job well done and just getting started!

EW Force is around the 90uN level at around 60W of Rf (~1.5mN/kW)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mr. Peter on 09/25/2015 06:23 AM
Congratulations rfmwguy, great work!
Looks like your puppy can beat the ballooning force.
Now we are all waiting for flip over test. Hopefully that'll  clear up any doubts.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: teitur on 09/25/2015 07:41 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)

Congratulations !
This setup is very impressive and to a guy with problems refilling cleaning liquid in the car it would seem almost impossible to build something this complex in your own garage.

I agree that the video indicates thrust, but to paraphrase Churchill - this is not the end, this is not even the beginning of the end. I would say it is not even the end of the beginning. Now the real testing can start.

For a start I would like much longer runs of the device and if possible to make the magnetron active for a longer time. It is imperative to collect as much good data as possible in this configuration.

Later of course it would be very interesting to try to vary parameters in the setup to try to find out what makes this thing tick.

Thanks a lot for your incredible good work and for giving us the opportunity to share in the experience.
Teitur

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 08:28 AM
Some NSF-1701 number crunching.

Assuming the magnetron was working into a resonant load, with a decent VSWR delivering 90% of the 700Ws into the frustum (630W), a Df of 0.54 and 0.018gf generation, the derived unloaded Q would have been around 80, measurable loaded Q then would be 40 or 50% the unloaded Q as per latest Shawyer emails.

This would suggest that either the magnetron was not working into a resonant load. the VSWR was bad or the mesh sides induced enough losses to reduce the Q to a very low value or some combination of some or all 3 potential issues. I suspect because of the intermittent nature of the Force ON and Force OFF signals, that the magnetron was slightly off ideal resonant frequency and it would sometimes lock onto / trigger the frustum resonant freq and sometimes not depending on the initial power on burst of frequencies. EW has seen this intermittent lockon resonant effect.

Without a rtn loss scan across the magnetrons freq range, giving resonant freq, bandwidth, loaded Q and VSWR it is not possible to tell why the generated Force was so low. But with that data in hand, it should be possible to increase the Force generation by optimisation of the operational parameters.

So we have a good start, a peg in the ground. Now is the time to flesh out the results and work to optimise the Force generation.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Left Field on 09/25/2015 08:52 AM
Great job rfmwguy. The data looks really promising.

I have noticed that microwave ovens (at least the older types - my current non-inverter model does not) make two kinds of humming sound while operating. You can hear it hum when it first comes on, but then moments later there is a deeper, more resonant hum, when subjectively, the contents of the microwave are more strongly affected. The reason I am pointing this out is because the thrust effect seems to be more noticeable on your graph during the louder hum stage.

Looking at your final 30% power cycle run for 3 minutes, I timed the different stages using a stopwatch and averaged them to give these durations:

Magnetron on (low hum): 6.25s
Magnetron on (louder hum): 4.44s
Magnetron off: 14.22s

The sum of these figures gives the total cycle time for 30% of 24.91s.

What is perplexing is that 30% of the cycle time is 24.91 * 0.3 = 7.47s, which suggests that that should be the total magnetron on time for each cycle, but as we can see the magnetron sounds like it is active for 6.25 + 4.44 = 10.69s, which is 43% of the total cycle time. Does this suggest that there is a difference in the effective heating ability of the microwave between the low hum and louder hum stages and the microwave's own timings account for this? Perhaps running the test again at 170oC, but with a greater or maximum power setting would show a larger effect?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/25/2015 10:02 AM
Congratulations Rfmwguy, your test setup is showing great resolution, and the results are really interesting! Here are a few reactions...

18mg is 177 micro Newton. A 700W photon rocket is 2 micro Newton. Even if all the power got into the frustrum, which it doesn't, that's something to explain.

People will doubtless quibble about a few things:

1. The signal to noise ratio is still quite low.
2. The natural frequency of the beam seems not so far from the 'on' cycle period at 30%
3. They will start to hunt for non-thermal artefacts.

You can address the first two by doing a long run at a different power setting. I would just set the power level to 50% and set the thing to run for as long as you can manage without filling up the data-logger's disk - then go and get some lunch!

The longer dataset will make it easier to extract the regular signal from Noise. The longer the system runs, the closer it should get to thermal equilibrium, and the lower the obscuring jump up when the magnetron goes off.

The other thing which would make analysis easier would be a second stream of data on the same timescale in the datalogger corresponding to the magnetron power input. Since much of the argument for thrust is about the timing of movements of the beam, it is important not to have to approximate (say from the soundtrack) when these are relative to the power input.

As regards non-thermal artefacts, the first argument is likely to be that the power through the cables is creating Lorentz forces which you are reading as thrust. In order to satisfy skeptics you would probably need to run a control experiment with the same magnetron operation sequence, but without injecting power into the frustrum (or maybe with the frustrum open at one end?).

Might that be possible?

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Fugudaddy on 09/25/2015 10:56 AM
Yay for data! Yay for a definitive force working against thermal lift!

Congratulations rfmwguy, amazing work. I can hear the excitement in your voice in the video but hey; these are exciting results. Your contribution in regards to 'defeating' thermal effects has been fantastic. The numbers people around here are going to have a field day today with all this data, and the more to come.

Keep flying!
Ronald
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/25/2015 11:39 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)

are the raw voltage measurement files available?  If so can you upload them please?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 12:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429456#msg1429456">Quote from: TheTraveller on 09/25/2015 06:04 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)

Congratulations on your good work.

Elimination of thermal lift is, as you have so clearly shown, of high importance, to improve the signal to noise ratio of the Force generation signal.

Makes the EW atmo measured EMDrive Force signatures highly significant, where they also had thermal issues to deal with.

I'm sure Iulian will enjoy seeing your data as his data is comparable. Attached is the scale force I observed from his upward Force video. It is clear there is thermal lift but it is also clear as the power is switch off, how quickly his Force dropped, which you also observed.
Thanks Mr T. I have to thank you as well, for it was you and Doc that suggested I build the dielectric-less frustum at 10.2 inches height. This was good insight. A dielectric in the frustum would "compress" the height to the original 9 inches. Without it, it expanded height just as predicted. Appreciate it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429484#msg1429484">Quote from: teitur on 09/25/2015 07:41 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)

Congratulations !
This setup is very impressive and to a guy with problems refilling cleaning liquid in the car it would seem almost impossible to build something this complex in your own garage.

I agree that the video indicates thrust, but to paraphrase Churchill - this is not the end, this is not even the beginning of the end. I would say it is not even the end of the beginning. Now the real testing can start.

For a start I would like much longer runs of the device and if possible to make the magnetron active for a longer time. It is imperative to collect as much good data as possible in this configuration.

Later of course it would be very interesting to try to vary parameters in the setup to try to find out what makes this thing tick.

Thanks a lot for your incredible good work and for giving us the opportunity to share in the experience.
Teitur
Thanks Teitur. Very observant on the messy floor. I blame my old 1973 Olds for the drips  ;) Which BTW, I just got back from the shop with a rebuilt engine, so hopefully no more leaks...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429496#msg1429496">Quote from: Left Field on 09/25/2015 08:52 AM</a>
Great job rfmwguy. The data looks really promising.

I have noticed that microwave ovens (at least the older types - my current non-inverter model does not) make two kinds of humming sound while operating. You can hear it hum when it first comes on, but then moments later there is a deeper, more resonant hum, when subjectively, the contents of the microwave are more strongly affected. The reason I am pointing this out is because the thrust effect seems to be more noticeable on your graph during the louder hum stage.

Looking at your final 30% power cycle run for 3 minutes, I timed the different stages using a stopwatch and averaged them to give these durations:

Magnetron on (low hum): 6.25s
Magnetron on (louder hum): 4.44s
Magnetron off: 14.22s

The sum of these figures gives the total cycle time for 30% of 24.91s.

What is perplexing is that 30% of the cycle time is 24.91 * 0.3 = 7.47s, which suggests that that should be the total magnetron on time for each cycle, but as we can see the magnetron sounds like it is active for 6.25 + 4.44 = 10.69s, which is 43% of the total cycle time. Does this suggest that there is a difference in the effective heating ability of the microwave between the low hum and louder hum stages and the microwave's own timings account for this? Perhaps running the test again at 170oC, but with a greater or maximum power setting would show a larger effect?
I found this hum difference unusual as well, for the microwave controller has no way to control voltage other than on/off. My suspicion is the frustum is going through some sort of resonance cycle on its own. If someone were to be able to lock this in, I think the results would be spectacular.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: teitur on 09/25/2015 01:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429536#msg1429536">Quote from: rfmwguy on 09/25/2015 01:01 PM</a>
Thanks Teitur. Very observant on the messy floor. I blame my old 1973 Olds for the drips  ;) Which BTW, I just got back from the shop with a rebuilt engine, so hopefully no more leaks...

I am very sorry this came out wrong. The guy with technical disabilities I was talking about was me !
Not even in my wildest dreams would I be able to build something like this.

Thanks again and I look forward to more magic from you.
Teitur

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/25/2015 01:10 PM
It will be a bit until I can fully test rfmwguy, but it would help tremendously if you could profile your frustum with a VNA. It will be a bit until I can test and I'm offering to loan my VMA and software along with the Spectrum analyzer. I can have it to you by this Monday. Use it for a week then send it back.

It's very important and you're a fellow Crazy Eddie DYIer. PM me!

A job very well done rfmwguy. Listening to the sound I can hear the associated magnetron lock after a second or so and then see the defection of the beam, I believe you're right on the edge of a mode lock and maybe you are using one of the lower power sub-harmonics of the magnetron to do it.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/25/2015 01:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429536#msg1429536">Quote from: rfmwguy on 09/25/2015 01:01 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429484#msg1429484">Quote from: teitur on 09/25/2015 07:41 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it.

Thanks a lot for your incredible good work and for giving us the opportunity to share in the experience.
Teitur
Thanks Teitur. Very observant on the messy floor. I blame my old 1973 Olds for the drips  ;) Which BTW, I just got back from the shop with a rebuilt engine, so hopefully no more leaks...
rfmwcarguy it has a nice ring to it. My own 65 Pontiac Grand Prix.

Seriously, take me up on the VNA and SA and I'll send some oil dry too.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/25/2015 01:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429538#msg1429538">Quote from: rfmwguy on 09/25/2015 01:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429496#msg1429496">Quote from: Left Field on 09/25/2015 08:52 AM</a>
Great job rfmwguy. The data looks really promising.

I have noticed that microwave ovens (at least the older types - my current non-inverter model does not) make two kinds of humming sound while operating. You can hear it hum when it first comes on, but then moments later there is a deeper, more resonant hum, when subjectively, the contents of the microwave are more strongly affected. The reason I am pointing this out is because the thrust effect seems to be more noticeable on your graph during the louder hum stage.

Looking at your final 30% power cycle run for 3 minutes, I timed the different stages using a stopwatch and averaged them to give these durations:

Magnetron on (low hum): 6.25s
Magnetron on (louder hum): 4.44s
Magnetron off: 14.22s

The sum of these figures gives the total cycle time for 30% of 24.91s.

What is perplexing is that 30% of the cycle time is 24.91 * 0.3 = 7.47s, which suggests that that should be the total magnetron on time for each cycle, but as we can see the magnetron sounds like it is active for 6.25 + 4.44 = 10.69s, which is 43% of the total cycle time. Does this suggest that there is a difference in the effective heating ability of the microwave between the low hum and louder hum stages and the microwave's own timings account for this? Perhaps running the test again at 170oC, but with a greater or maximum power setting would show a larger effect?
I found this hum difference unusual as well, for the microwave controller has no way to control voltage other than on/off. My suspicion is the frustum is going through some sort of resonance cycle on its own. If someone were to be able to lock this in, I think the results would be spectacular.

First - mega cudos rfmwguy - this is outstanding.   And shows once again that science is based on approach, intellectual honesty, attitude and diligence rather than megabuck budget.
 
My first thought on the noise change when I read LeftField's post - good ear BTW - my old ones didn't detect that   :) was also some sort of resonance effect delta .   We have had much discussion on cyclic/non-steady state effects inside the frustum but this would be something very interesting as it is at a much longer time scale than the simulations have looked at.   Six seconds and four seconds are an eternity for most effects at Ghz ranges.   This is going to take some good old fashion noodling.   

Again - congrats!!!!!!

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:30 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429544#msg1429544">Quote from: graybeardsyseng on 09/25/2015 01:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429538#msg1429538">Quote from: rfmwguy on 09/25/2015 01:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429496#msg1429496">Quote from: Left Field on 09/25/2015 08:52 AM</a>
Great job rfmwguy. The data looks really promising.

I have noticed that microwave ovens (at least the older types - my current non-inverter model does not) make two kinds of humming sound while operating. You can hear it hum when it first comes on, but then moments later there is a deeper, more resonant hum, when subjectively, the contents of the microwave are more strongly affected. The reason I am pointing this out is because the thrust effect seems to be more noticeable on your graph during the louder hum stage.

Looking at your final 30% power cycle run for 3 minutes, I timed the different stages using a stopwatch and averaged them to give these durations:

Magnetron on (low hum): 6.25s
Magnetron on (louder hum): 4.44s
Magnetron off: 14.22s

The sum of these figures gives the total cycle time for 30% of 24.91s.

What is perplexing is that 30% of the cycle time is 24.91 * 0.3 = 7.47s, which suggests that that should be the total magnetron on time for each cycle, but as we can see the magnetron sounds like it is active for 6.25 + 4.44 = 10.69s, which is 43% of the total cycle time. Does this suggest that there is a difference in the effective heating ability of the microwave between the low hum and louder hum stages and the microwave's own timings account for this? Perhaps running the test again at 170oC, but with a greater or maximum power setting would show a larger effect?
I found this hum difference unusual as well, for the microwave controller has no way to control voltage other than on/off. My suspicion is the frustum is going through some sort of resonance cycle on its own. If someone were to be able to lock this in, I think the results would be spectacular.

First - mega cudos rfmwguy - this is outstanding.   And shows once again that science is based on approach, intellectual honesty, attitude and diligence rather than megabuck budget.
 
My first thought on the noise change when I read LeftField's post - good ear BTW - my old ones didn't detect that   :) was also some sort of resonance effect delta .   We have had much discussion on cyclic/non-steady state effects inside the frustum but this would be something very interesting as it is at a much longer time scale than the simulations have looked at.   Six seconds and four seconds are an eternity for most effects at Ghz ranges.   This is going to take some good old fashion noodling.   

Again - congrats!!!!!!

Herman
Thanks Herman...I wanted to keep the raw, "dirty" RF sprayed into the frustum just for this reason. I didn't build the frustum with the precision of a known, single frequency resonance. With a little luck, the instability of the messy RF I think passed through a resonance which probably shifted as the thing heated up anyway.

The wide signal (40 MHz) probably helped me overcome mechanical imperfections.  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:40 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429540#msg1429540">Quote from: SeeShells on 09/25/2015 01:10 PM</a>
It will be a bit until I can fully test rfmwguy, but it would help tremendously if you could profile your frustum with a VNA. It will be a bit until I can test and I'm offering to loan my VMA and software along with the Spectrum analyzer. I can have it to you by this Monday. Use it for a week then send it back.

It's very important and you're a fellow Crazy Eddie DYIer. PM me!

A job very well done rfmwguy. Listening to the sound I can hear the associated magnetron lock after a second or so and then see the defection of the beam, I believe you're right on the edge of a mode lock and maybe you are using one of the lower power sub-harmonics of the magnetron to do it.

Shell
Tell you what Shell, I am willing to mail you the frustum with a wifi antenna in place of the the radome and terminated with SMA female. I need a break from all the build and testing. Besides, we might as well get NSF-1701 over to our new International Filght Test Facility for possible further testing and formal display  ;D

PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dumbo on 09/25/2015 01:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)
If this effect is legit, that frustum will one day be in a museum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 01:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429545#msg1429545">Quote from: rfmwguy on 09/25/2015 01:30 PM</a>
Thanks Herman...I wanted to keep the raw, "dirty" RF sprayed into the frustum just for this reason. I didn't build the frustum with the precision of a known, single frequency resonance. With a little luck, the instability of the messy RF I think passed through a resonance which probably shifted as the thing heated up anyway.

The wide signal (40 MHz) probably helped me overcome mechanical imperfections.  8)

Based on information that has been shared with me, what I saw in your Force generation profiles suggests your frustum may be operation on the side slope of a resonant mode that sometimes fills and resonates the cavity and sometime not. As I understand this operational characteristic, being spot on centre resonance delivers high reliability resonant locks and the further you operate down the slope, away from peak resonance, the more unreliable the resonant lock becomes.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 01:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429554#msg1429554">Quote from: dumbo on 09/25/2015 01:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)
If this effect is legit, that frustum will one day be in a museum.
Yes, maybe we should call it Shell's International Emdrive Flight Test Facility and Museum  ::)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/25/2015 02:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429540#msg1429540">Quote from: SeeShells on 09/25/2015 01:10 PM</a>
It will be a bit until I can fully test rfmwguy, but it would help tremendously if you could profile your frustum with a VNA. It will be a bit until I can test and I'm offering to loan my VMA and software along with the Spectrum analyzer. I can have it to you by this Monday. Use it for a week then send it back.

It's very important and you're a fellow Crazy Eddie DYIer. PM me!

A job very well done rfmwguy. Listening to the sound I can hear the associated magnetron lock after a second or so and then see the defection of the beam, I believe you're right on the edge of a mode lock and maybe you are using one of the lower power sub-harmonics of the magnetron to do it.

Shell
Tell you what Shell, I am willing to mail you the frustum with a wifi antenna in place of the the radome and terminated with SMA female. I need a break from all the build and testing. Besides, we might as well get NSF-1701 over to our new International Filght Test Facility for possible further testing and formal display  ;D

PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)
You know, I'll be glad to take some time to test it out if you want me to and I'll send it back when I'm done. Expect a PM with my email and address.

Understand the soul needing a break, many don't realize for the few minutes of run-time video the hours that go into the little details. You deserve a break, take your SO out for a nice candle light dinner and thank her from all of us here for putting up with a Crazy Eddie.

And Thank You rfmwguy!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/25/2015 02:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429558#msg1429558">Quote from: rfmwguy on 09/25/2015 01:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429554#msg1429554">Quote from: dumbo on 09/25/2015 01:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)
If this effect is legit, that frustum will one day be in a museum.
Yes, maybe we should call it Shell's International Emdrive Flight Test Facility and Museum  ::)
ACK! Please, I haven't even had a hot tub this morning.  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/25/2015 03:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429557#msg1429557">Quote from: TheTraveller on 09/25/2015 01:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429545#msg1429545">Quote from: rfmwguy on 09/25/2015 01:30 PM</a>
Thanks Herman...I wanted to keep the raw, "dirty" RF sprayed into the frustum just for this reason. I didn't build the frustum with the precision of a known, single frequency resonance. With a little luck, the instability of the messy RF I think passed through a resonance which probably shifted as the thing heated up anyway.

The wide signal (40 MHz) probably helped me overcome mechanical imperfections.  8)

Based on information that has been shared with me, what I saw in your Force generation profiles suggests your frustum may be operation on the side slope of a resonant mode that sometimes fills and resonates the cavity and sometime not. As I understand this operational characteristic, being spot on centre resonance delivers high reliability resonant locks and the further you operate down the slope, away from peak resonance, the more unreliable the resonant lock becomes.

I love the collaborative nature of this forum - heck the whole "internets" thing  ;)

As I was taking care of some chores this AM I was just thinking about this very concept.   I think we have (at least) three  "curves" intersecting here.

First - the wide band (40 Mhz) Maggie output peak likely slides up and down and interacts with the resonance curve of the frustum.
Second -  the frustum resonance curve may also be changing with temperature.   I was thinking about the mesh and heating from the power being cycled up and down.  I think it may be experiencing some non-linear expansion and contraction with heat up and cool down.   I know the frustum isn't any where near the temp of the Maggie, BUT it likely wouldn't take much.   IIRC several pages (maybe several dozen) there was some general discussion that the geometry of the frustum varying a very small amount (IIRC less than a mm) then that could significantly affect resonance.  The wire mesh has less thermal mass so any change would likely be more noticeable.   I have no idea how this would affect resonance curves. 

Third - the interaction of the above factors will affect the VSWR/return loss and thus the feedback of power to the Maggie.   When in turn will affect the magnetrons output.   One more interacting factor.

My experience when you have multi-dimensional interactions like this is the time frame for "peaks and valleys" of interaction can appear completely out of scale with other time constants of the system.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/25/2015 03:53 PM

Hum according to the hackaday Babby EMDrive page they're making horizontal force measurements.  Also we've been reading the graphs wrong. Here is what they are saying:

Quote
Here´s how the chart works:

- On the left side is the camera image of the interference pattern. The grey graph is a continous sampling of the yellow line in the interference image, so if the pattern moves up, the grey graph also moves up.

- The green graph is just the pixel brightness sum within the thick green line in the interference image. It will generate a more or less sinusoidal wave over time when the pattern is moving continously. However, it will not tell you the direction in which the interference patern is moving, but it might be helpful to make small changes more visible.

- After having adjusted the mirror to get a good interference pattern, it´s not clear in which direction the pattern will move in respect to the force.
I use a magnet to determine that. My reference will be "U" if the rings of the pattern go up and "D" if they go down while attracting the platform with the magnet.

It looks like they are reporting horizontal movement towards the small base, though I worry that they are not outside of the noise. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 03:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429602#msg1429602">Quote from: graybeardsyseng on 09/25/2015 03:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429557#msg1429557">Quote from: TheTraveller on 09/25/2015 01:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429545#msg1429545">Quote from: rfmwguy on 09/25/2015 01:30 PM</a>
Thanks Herman...I wanted to keep the raw, "dirty" RF sprayed into the frustum just for this reason. I didn't build the frustum with the precision of a known, single frequency resonance. With a little luck, the instability of the messy RF I think passed through a resonance which probably shifted as the thing heated up anyway.

The wide signal (40 MHz) probably helped me overcome mechanical imperfections.  8)

Based on information that has been shared with me, what I saw in your Force generation profiles suggests your frustum may be operation on the side slope of a resonant mode that sometimes fills and resonates the cavity and sometime not. As I understand this operational characteristic, being spot on centre resonance delivers high reliability resonant locks and the further you operate down the slope, away from peak resonance, the more unreliable the resonant lock becomes.

I love the collaborative nature of this forum - heck the whole "internets" thing  ;)

As I was taking care of some chores this AM I was just thinking about this very concept.   I think we have (at least) three  "curves" intersecting here.

First - the wide band (40 Mhz) Maggie output peak likely slides up and down and interacts with the resonance curve of the frustum.
Second -  the frustum resonance curve may also be changing with temperature.   I was thinking about the mesh and heating from the power being cycled up and down.  I think it may be experiencing some non-linear expansion and contraction with heat up and cool down.   I know the frustum isn't any where near the temp of the Maggie, BUT it likely wouldn't take much.   IIRC several pages (maybe several dozen) there was some general discussion that the geometry of the frustum varying a very small amount (IIRC less than a mm) then that could significantly affect resonance.  The wire mesh has less thermal mass so any change would likely be more noticeable.   I have no idea how this would affect resonance curves. 

Third - the interaction of the above factors will affect the VSWR/return loss and thus the feedback of power to the Maggie.   When in turn will affect the magnetrons output.   One more interacting factor.

My experience when you have multi-dimensional interactions like this is the time frame for "peaks and valleys" of interaction can appear completely out of scale with other time constants of the system.

Herman
You're thinking along the same lines I am. If someone hits on a way to "lock in" to this effect, my mere 18 mg of force will likely triple, at least.

Already, we're smacking down a theoretical photon drive by most accounts.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/25/2015 04:01 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429610#msg1429610">Quote from: rfmwguy on 09/25/2015 03:53 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429602#msg1429602">Quote from: graybeardsyseng on 09/25/2015 03:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429557#msg1429557">Quote from: TheTraveller on 09/25/2015 01:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429545#msg1429545">Quote from: rfmwguy on 09/25/2015 01:30 PM</a>
Thanks Herman...I wanted to keep the raw, "dirty" RF sprayed into the frustum just for this reason. I didn't build the frustum with the precision of a known, single frequency resonance. With a little luck, the instability of the messy RF I think passed through a resonance which probably shifted as the thing heated up anyway.

The wide signal (40 MHz) probably helped me overcome mechanical imperfections.  8)

Based on information that has been shared with me, what I saw in your Force generation profiles suggests your frustum may be operation on the side slope of a resonant mode that sometimes fills and resonates the cavity and sometime not. As I understand this operational characteristic, being spot on centre resonance delivers high reliability resonant locks and the further you operate down the slope, away from peak resonance, the more unreliable the resonant lock becomes.

I love the collaborative nature of this forum - heck the whole "internets" thing  ;)

As I was taking care of some chores this AM I was just thinking about this very concept.   I think we have (at least) three  "curves" intersecting here.

First - the wide band (40 Mhz) Maggie output peak likely slides up and down and interacts with the resonance curve of the frustum.
Second -  the frustum resonance curve may also be changing with temperature.   I was thinking about the mesh and heating from the power being cycled up and down.  I think it may be experiencing some non-linear expansion and contraction with heat up and cool down.   I know the frustum isn't any where near the temp of the Maggie, BUT it likely wouldn't take much.   IIRC several pages (maybe several dozen) there was some general discussion that the geometry of the frustum varying a very small amount (IIRC less than a mm) then that could significantly affect resonance.  The wire mesh has less thermal mass so any change would likely be more noticeable.   I have no idea how this would affect resonance curves. 

Third - the interaction of the above factors will affect the VSWR/return loss and thus the feedback of power to the Maggie.   When in turn will affect the magnetrons output.   One more interacting factor.

My experience when you have multi-dimensional interactions like this is the time frame for "peaks and valleys" of interaction can appear completely out of scale with other time constants of the system.

Herman
You're thinking along the same lines I am. If someone hits on a way to "lock in" to this effect, my mere 18 mg of force will likely triple, at least.

Already, we're smacking down a theoretical photon drive by most accounts.

"triple, at least"  - Amen.   For those out there not familiar with resonance and resonant phenomenon - tripling might be very very conservative.   

H.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 04:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429610#msg1429610">Quote from: rfmwguy on 09/25/2015 03:53 PM</a>
You're thinking along the same lines I am. If someone hits on a way to "lock in" to this effect, my mere 18 mg of force will likely triple, at least.

Already, we're smacking down a theoretical photon drive by most accounts.

Would bet doing a SLOW VNA scan across the maggie freq range just might give you the info you need to turn the 18 mgs of Force (~175uNs) into 100 mgs of Force. ;)

As example, EWs atmo Force is around 1.5mN/kW. Assuming equal Q and good VSWR, your 700W could gen around 1mN or 100mg as above.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zellerium on 09/25/2015 04:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429540#msg1429540">Quote from: SeeShells on 09/25/2015 01:10 PM</a>
It will be a bit until I can fully test rfmwguy, but it would help tremendously if you could profile your frustum with a VNA. It will be a bit until I can test and I'm offering to loan my VMA and software along with the Spectrum analyzer. I can have it to you by this Monday. Use it for a week then send it back.

It's very important and you're a fellow Crazy Eddie DYIer. PM me!

A job very well done rfmwguy. Listening to the sound I can hear the associated magnetron lock after a second or so and then see the defection of the beam, I believe you're right on the edge of a mode lock and maybe you are using one of the lower power sub-harmonics of the magnetron to do it.

Shell
Tell you what Shell, I am willing to mail you the frustum with a wifi antenna in place of the the radome and terminated with SMA female. I need a break from all the build and testing. Besides, we might as well get NSF-1701 over to our new International Filght Test Facility for possible further testing and formal display  ;D

PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)

Congrats rfmwguy! You're an inspiration to all of us.

As far as the VNA is concerned, I would recommend either buying a professionally made  SMA to magnetron antenna or making your own. I don't know how close the magnetron is to a wifi antenna, you are probably more knowledgable on the subject.

The antenna adapter we made seemed to work well: we had significant deflection at a point determined to be resonance and a cm away we saw zero deflection where it shouldn't have resonated. Although this deflection might have been caused by an asymmetric flow of current, the resonant position must have had orders of magnitude higher surface currents.

Making the adapter is simple, buy an identical magnetron, take it apart and carefully cut through the center where the tap wire attaches to the spokes, and solder an SMA panel mount to it.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 04:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429634#msg1429634">Quote from: zellerium on 09/25/2015 04:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429540#msg1429540">Quote from: SeeShells on 09/25/2015 01:10 PM</a>
It will be a bit until I can fully test rfmwguy, but it would help tremendously if you could profile your frustum with a VNA. It will be a bit until I can test and I'm offering to loan my VMA and software along with the Spectrum analyzer. I can have it to you by this Monday. Use it for a week then send it back.

It's very important and you're a fellow Crazy Eddie DYIer. PM me!

A job very well done rfmwguy. Listening to the sound I can hear the associated magnetron lock after a second or so and then see the defection of the beam, I believe you're right on the edge of a mode lock and maybe you are using one of the lower power sub-harmonics of the magnetron to do it.

Shell
Tell you what Shell, I am willing to mail you the frustum with a wifi antenna in place of the the radome and terminated with SMA female. I need a break from all the build and testing. Besides, we might as well get NSF-1701 over to our new International Filght Test Facility for possible further testing and formal display  ;D

PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)

Congrats rfmwguy! You're an inspiration to all of us.

As far as the VNA is concerned, I would recommend either buying a professionally made  SMA to magnetron antenna or making your own. I don't know how close the magnetron is to a wifi antenna, you are probably more knowledgable on the subject.

The antenna adapter we made seemed to work well: we had significant deflection at a point determined to be resonance and a cm away we saw zero deflection where it shouldn't have resonated. Although this deflection might have been caused by an asymmetric flow of current, the resonant position must have had orders of magnitude higher surface currents.

Making the adapter is simple, buy an identical magnetron, take it apart and carefully cut through the center where the tap wire attaches to the spokes, and solder an SMA panel mount to it.
Great idea! Since I'm sending the frustum to Shell, would you be willing to loan her your SMA to Radome converter so she can make a VNA sweep? This would be much better than the wifi antenna I planned to mount in the frustum...pending her approval, of course.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 05:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429634#msg1429634">Quote from: zellerium on 09/25/2015 04:47 PM</a>
Making the adapter is simple, buy an identical magnetron, take it apart and carefully cut through the center where the tap wire attaches to the spokes, and solder an SMA panel mount to it.

Nicely done. ;)

That is the way to do the VNA scans when using a maggie.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/25/2015 05:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429639#msg1429639">Quote from: rfmwguy on 09/25/2015 04:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429634#msg1429634">Quote from: zellerium on 09/25/2015 04:47 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429548#msg1429548">Quote from: rfmwguy on 09/25/2015 01:40 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429540#msg1429540">Quote from: SeeShells on 09/25/2015 01:10 PM</a>
It will be a bit until I can fully test rfmwguy, but it would help tremendously if you could profile your frustum with a VNA. It will be a bit until I can test and I'm offering to loan my VMA and software along with the Spectrum analyzer. I can have it to you by this Monday. Use it for a week then send it back.

It's very important and you're a fellow Crazy Eddie DYIer. PM me!

A job very well done rfmwguy. Listening to the sound I can hear the associated magnetron lock after a second or so and then see the defection of the beam, I believe you're right on the edge of a mode lock and maybe you are using one of the lower power sub-harmonics of the magnetron to do it.

Shell
Tell you what Shell, I am willing to mail you the frustum with a wifi antenna in place of the the radome and terminated with SMA female. I need a break from all the build and testing. Besides, we might as well get NSF-1701 over to our new International Filght Test Facility for possible further testing and formal display  ;D

PM me with your address and I'll mail it out to you in a couple of days. Don't lose it, I might want it back sometime  ;)

Congrats rfmwguy! You're an inspiration to all of us.

As far as the VNA is concerned, I would recommend either buying a professionally made  SMA to magnetron antenna or making your own. I don't know how close the magnetron is to a wifi antenna, you are probably more knowledgable on the subject.

The antenna adapter we made seemed to work well: we had significant deflection at a point determined to be resonance and a cm away we saw zero deflection where it shouldn't have resonated. Although this deflection might have been caused by an asymmetric flow of current, the resonant position must have had orders of magnitude higher surface currents.

Making the adapter is simple, buy an identical magnetron, take it apart and carefully cut through the center where the tap wire attaches to the spokes, and solder an SMA panel mount to it.
Great idea! Since I'm sending the frustum to Shell, would you be willing to loan her your SMA to Radome converter so she can make a VNA sweep? This would be much better than the wifi antenna I planned to mount in the frustum...pending her approval, of course.

I have a very dead maggie I'll use and it'a a great idea plus I will have a good magnet too boot.

Shell

Out for a bit, going to see what my water jet guys did or didn't.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 06:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429651#msg1429651">Quote from: SeeShells on 09/25/2015 05:09 PM</a>
I have a very dead maggie I'll use and it'a a great idea plus I will have a good magnet too boot.

Shell

Out for a bit, going to see what my water jet guys did or didn't.

How to cut out the maggie antenna. Might want to slow down the replay speed at the end a bit but you should get the idea.

https://youtu.be/q09BniPSU2Y

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: kencolangelo on 09/25/2015 07:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)
I think it'd be enlightening to see the voltage from the laser measured in much smaller time intervals, maybe a couple times a second, even 60hz or more if we can get it. I think I see your point about the thrust fighting the thermal lift but the actual events are fairly short and only comprise a few samples. I don't know where this is going next but that's my two cents. The oscillations and turbulence caused by the thermal currents seem to be nearly as great as the possible thrust, more resolution would, I think, give a much clearer picture and more detail may show other interesting behaviors currently invisible.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 08:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429686#msg1429686">Quote from: kencolangelo on 09/25/2015 07:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429453#msg1429453">Quote from: rfmwguy on 09/25/2015 05:52 AM</a>
I guess I can say now that after more than a year in planning, building and testing, I've proven to myself that there is something to this and we need to continue to pursue it. I consider the test positive with a force against  thermal lift of approximately 18 mg average. Not every mag fire up gave that reading since often it simply held back lift, but I believe this is a good approximation. This should help others scale their test setups to be able to measure this small amount of force against a much stronger thermal lift. Preheat and go for it  :)
I think it'd be enlightening to see the voltage from the laser measured in much smaller time intervals, maybe a couple times a second, even 60hz or more if we can get it. I think I see your point about the thrust fighting the thermal lift but the actual events are fairly short and only comprise a few samples. I don't know where this is going next but that's my two cents. The oscillations and turbulence caused by the thermal currents seem to be nearly as great as the possible thrust, more resolution would, I think, give a much clearer picture and more detail may show other interesting behaviors currently invisible.
I agree. This test was all about setting the stage the best I could for myself and allowing others to take what I have learned and go from there.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/25/2015 08:57 PM
rfmwguy,

It was very interesting to see your test and yes, although - yet again - not conclusive, your results did provide enough information to sustain curiosity in the possible force generation in an EMdrive.

Let me say it in a prudent way: you've provided results that might indicate that the EMdrive does indeed produce a force but it is still far from a proven fact...

On a side note, I wonder if your open mesh does not considerably contribute to the large buoyancy lift you've experienced.

I also think a small plate+screw+stepper motor would be essential to achieve better performance, as by general consensus on this forum, the resonance patterns have a link with the possible generate force...So having the ability to tweak the length of the frustum and consequently optimize the internal resonance would be essential to obtain irrefutable evidence (instead of flimsy indications).

You did succeed to give the EMdrive a little nudge upward in credibility, which is a great achievement on itself. But there is still a long way to go... ;)
Anyway, thumbs up man !!!
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RotoSequence on 09/25/2015 09:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429710#msg1429710">Quote from: rfmwguy on 09/25/2015 08:52 PM</a>
I agree. This test was all about setting the stage the best I could for myself and allowing others to take what I have learned and go from there.

I wish you weren't ready to take that break just yet. I'm still waiting for a DIY builder to replicate thrust and follow up with a battery of modifications to amplify the measured thrust, and null tests to quell lingering skepticism.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/25/2015 09:26 PM
Reddit user True-Creek did a supurb job of tone-decoding magnetron hum (on) and matching it against a trace. Note pauses to lift, lift resume and downward deflection in the blue area (mag on) and white area (mag off). Some traces in the blue area looks like it was trying to form, but could not.

Here are several data points to consider for yourself:

"I just ran a screenshot of the video through ImageJ and a Java-plugin that extracts the column-wise maximum. I've also extracted the the humming from the magentron (235.5-240 Hz) but it needed some correction:

0ioKt7B.png

It looks much more convincing than the impression I got from the video. There are about N=12 full trials and in 10/12 trials there is no obvious lift. In 9/12 trials there were lifts shortly after they ended. In only 6 or 7 there were significant drops.

Edit: Here is the data of the graph, though not normalized but in the original aspect ratio: http://pastebin.com/raw.php?i=eM5rLVXy "  by true-creek on reddit/emdrive 9/25/15
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/25/2015 10:11 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429720#msg1429720">Quote from: rfmwguy on 09/25/2015 09:26 PM</a>
Reddit user True-Creek did a supurb job of tone-decoding magnetron hum (on) and matching it against a trace. Note pauses to lift, lift resume and downward deflection in the blue area (mag on) and white area (mag off). Some traces in the blue area looks like it was trying to form, but could not.

Here are several data points to consider for yourself:

"I just ran a screenshot of the video through ImageJ and a Java-plugin that extracts the column-wise maximum. I've also extracted the the humming from the magentron (235.5-240 Hz) but it needed some correction:

0ioKt7B.png

It looks much more convincing than the impression I got from the video. There are about N=12 full trials and in 10/12 trials there is no obvious lift. In 9/12 trials there were lifts shortly after they ended. In only 6 or 7 there were significant drops.

Edit: Here is the data of the graph, though not normalized but in the original aspect ratio: http://pastebin.com/raw.php?i=eM5rLVXy "  by true-creek on reddit/emdrive 9/25/15
Very very interesting.   Particularly the 9/12 cases of lift shortly after power off (if I am understanding this graphic).   To me this looks very much like what I would expect to see with a wild freq. source and variable degree of resonance.   In particular, the delayed effect could be coming from residual energy at a "correct" frequency still in system after the overall drive with others in the spectrum removed.   Thinking as I type so this probably isn't clear but that graph was very exciting.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/25/2015 10:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429433#msg1429433">Quote from: TheTraveller on 09/25/2015 04:04 AM</a>
Recent email corro with Roger Shawyer.

There is a lot of real engineering information and solid answers in this exchange.

The difference between the loaded and unloaded Q Roger has shared with an ideal injection match is new information and is why I believe SPR are now doing pulsed injection as after the Rf injection period is over (and the associated injection caused phase distortion) the cavity is them able to form a non phase distorted resonant condition, doubling the cavity Q (going from loaded Q to unloaded Q) and Force generation.

Roger makes this clear in his statement about the Flight Thruster and how the Force generated matches the doubled unloaded Q and not the 1/2 lower loaded, Rf injection period Q.

So as Roger explains in his latest patent application, the main Force is generated AFTER the Rf injection is switched off. Why? Because after the Rf pulse stops, the cavity Q doubles as it can now operate in an unloaded mode.

Nice breadcrumbs Roger. You have answered a lot of my questions.

Thanks.

> Hi Roger,
>
> I'm home again, recovering from the effects of the super bug I picked up in
> hospital. Have a deep wound, caused by the super bug, where one of the
> robot arms entered by abdomen. Like a 2nd belly button. Docs want me to
> take it very gentle until it starts to naturally regrow. They don't want to
> close it up just yet, just to be sure to not close with some of the
> superbug bacteria still active inside. So for now I have a patch over my
> 2nd belly button and daily nurse visits.
>
> So some time before I'm allowed in my workshop. But not wasting the time.
>
> Most of the software for the Raspberry PI 2B based control & monitoring
> system has been written. Will have a high power 5GHz WiFi based USB
> connection for control & data logging from the rotary table to my laptop.
>
> Point of discussion with others, NSF and myself. How do you / SPR measure
> frustum bandwidth / Q? Do you use bandwidth at 3dB away from max S11 rtn
> loss dB freq (as Prof Yang does) or 3dBs from 0 dB ref level as
> Eagleworks / NSF do or do you guys use another method? Would prefer to
> measure Q as you guys do. Makes a massive difference in bandwidth, Q &
> projected Force generation.

> Hi TT
>
> Using a network analyser to determine the Q of a high Q cavity via S11 is
> quick but requires a good understanding of the effect of scan speed and
> detector bandwidth or the results can be wildly inaccurate.
>
> For the delivery data of space qualified equipment, a calibrated procedure
> using separate signal source and power meter was usually specified. This is
> the technique we have always used at SPR.
>
> The signal source is put on a slow sweep to allow a dwell time of at least
> 10X time constant at each measurement point. The internal cavity power is
> measured using a cavity wall mounted detector measuring at least 30dB down
> (a very short probe!) and a wide detection bandwidth. The data is processed
> to measure the bandwidth 3dB down from max power level for at least two
> scans, one in each direction. (they must agree or there is a drift error in
> the measurement).
>
> Hope this helps.
>
> Best regards
>
> Roger

> Hi Roger,
>
> Thanks.
>
> So you prefer 2 port S21 over 1 port S11 or is S11 ok if the scan speed is
> VERY slow?
>
> I do understand the need for a SLOW scan and the frustum fill time / TC
> factor. What you shared is in line with my understanding.
>
> May I share this information on NSF cause there are a few arm chair
> "experts" that are strongly saying to measure bandwidth 3dB from the rtn
> loss 0dB reference level, which to me is madness.

> Hi TT
>
> S11 measurements are complicated if a highly tuned input circuit is used. I have seen published measurements that are clearly the Q of the input circuit only.
>
> Note that all Q measurements are Loaded Q measurements, and strictly speaking, if a perfect match is achieved, the actual unloaded Q is twice the measured Q.
>
> There are endless papers on the complications of Q measurement which is why smart customers are very careful about deliverable test data.
>
> The thrust predicted by the Thrust equation assumes unloaded Q. The measured thrust for the Flight thruster was very close to the predicted thrust when twice the measured Q was used in the equation.
>
> The design was successfully sold to Boeing on the measured thrust data.
>
> Feel free to share my comments on your forum.
>
> Best regards
>
> Roger

Knew I had just seen this.   I am thinking that this is very similar to what rfmwguy et al are seeing in his last previous post.   Sorry I don't know how to include multiple quotes in a reply.  I think what we may be seeing is sometimes called resonance chasing/dragging or resonance capture (a little different really).  I am really looking forward to Shell's results looking into this frustum.

H.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 11:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429733#msg1429733">Quote from: graybeardsyseng on 09/25/2015 10:19 PM</a>
Knew I had just seen this.   I am thinking that this is very similar to what rfmwguy et al are seeing in his last previous post.   Sorry I don't know how to include multiple quotes in a reply.  I think what we may be seeing is sometimes called resonance chasing/dragging or resonance capture (a little different really).  I am really looking forward to Shell's results looking into this frustum.

H.

Yup. Suspect you are correct. Rfmwguy's frustum is probably operation on one side of the resonance curve. Sometime the maggie pulls freq and locks, sometime not. Frustum load impedance varies with freq, offering better impedance match at some frequencies, worst at others. But very dynamic. So the maggie reacts.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/25/2015 11:24 PM
Suspect using a simple spectrum analyser when the maggie is running will show a clear change in the freq distribution patterns when the maggie locks to the frustum resonance and when it fails to lock.

At resonance an empty cavity will appear to be a very low impedance load to the maggie, at least for the 1st 1/2 of the 1st Time Constant. Sort of like a cap charging but sensitive to freq. The closer to resonance, at the start of the cavity fill process, the lower the initial charge load impedance and the further away from resonance the effect will reduce.

As the maggie outout is composed of hundreds of vaying freq, short duration Rf pulses, the cavity will be doing lots of fill and unfill cycles driven by the largely random nature of the maggie RF output bursts and the 60Hz on and off 1/2 wave power cycles.

Any resonance driven Freq pulling should be visible doing a spectrum scan..
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/26/2015 12:07 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429615#msg1429615">Quote from: graybeardsyseng on 09/25/2015 04:01 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429610#msg1429610">Quote from: rfmwguy on 09/25/2015 03:53 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429602#msg1429602">Quote from: graybeardsyseng on 09/25/2015 03:43 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429557#msg1429557">Quote from: TheTraveller on 09/25/2015 01:56 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429545#msg1429545">Quote from: rfmwguy on 09/25/2015 01:30 PM</a>
Thanks Herman...I wanted to keep the raw, "dirty" RF sprayed into the frustum just for this reason. I didn't build the frustum with the precision of a known, single frequency resonance. With a little luck, the instability of the messy RF I think passed through a resonance which probably shifted as the thing heated up anyway.

The wide signal (40 MHz) probably helped me overcome mechanical imperfections.  8)

Based on information that has been shared with me, what I saw in your Force generation profiles suggests your frustum may be operation on the side slope of a resonant mode that sometimes fills and resonates the cavity and sometime not. As I understand this operational characteristic, being spot on centre resonance delivers high reliability resonant locks and the further you operate down the slope, away from peak resonance, the more unreliable the resonant lock becomes.

I love the collaborative nature of this forum - heck the whole "internets" thing  ;)

As I was taking care of some chores this AM I was just thinking about this very concept.   I think we have (at least) three  "curves" intersecting here.

First - the wide band (40 Mhz) Maggie output peak likely slides up and down and interacts with the resonance curve of the frustum.
Second -  the frustum resonance curve may also be changing with temperature.   I was thinking about the mesh and heating from the power being cycled up and down.  I think it may be experiencing some non-linear expansion and contraction with heat up and cool down.   I know the frustum isn't any where near the temp of the Maggie, BUT it likely wouldn't take much.   IIRC several pages (maybe several dozen) there was some general discussion that the geometry of the frustum varying a very small amount (IIRC less than a mm) then that could significantly affect resonance.  The wire mesh has less thermal mass so any change would likely be more noticeable.   I have no idea how this would affect resonance curves. 

Third - the interaction of the above factors will affect the VSWR/return loss and thus the feedback of power to the Maggie.   When in turn will affect the magnetrons output.   One more interacting factor.

My experience when you have multi-dimensional interactions like this is the time frame for "peaks and valleys" of interaction can appear completely out of scale with other time constants of the system.

Herman
You're thinking along the same lines I am. If someone hits on a way to "lock in" to this effect, my mere 18 mg of force will likely triple, at least.

Already, we're smacking down a theoretical photon drive by most accounts.

"triple, at least"  - Amen.   For those out there not familiar with resonance and resonant phenomenon - tripling might be very very conservative.   

H.

Even driving with a Inverter stabilized magnetron, I'll still have from last look about 3-5 modes running through the frustum that will all work for resonance or degrade it.

This is why I wanted a stable and symmetrical input into the frustum, there seems to be enough resonant phenomenon going on with just the shape at TE012. In some of the simulations of the Crazy Eddie frustum with waveguide inputs I can see TE01, TE012 and another.

 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 09/26/2015 01:09 AM
For DIY's  Thermal Mitigation:

Suggestion: spray paint magnetron with a thin coat of BBQ flat black paint instead of leaving them in their natural shiny aluminium state to run slightly cooler temperatures possibly worth  -3°C+  if the car forums have it right

From Black Intercoolers Mythbusted: https://www.youtube.com/watch?v=f1QL9veQaNg

Real life examples: in simular temp ranges: motorcycle fins, Corvettes, nascar, and the F1's in stationary use, car racing aluminium radiators, electronic heat sinks. etc..

 theory: https://en.wikipedia.org/wiki/Black_body

Possible criticism: the heated air coming off is "hotter" hence greater more thermal air rising chimney  effect?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: mwvp on 09/26/2015 07:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429316#msg1429316">Quote from: SeeShells on 09/24/2015 11:07 PM</a>
Areo and I got the dual opposing waveguides working, wasn't sure what we would see but I hoped for a symmetrical mode generation and there was. Taking a slices of time through the CE  frustum it is apparent that there are at least 2 modes overlaying each other.

That's the kind of traveling wave I expected to see. Very nice! Would like to see the outline/dimensions of the cavity and feed waveguide.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: mwvp on 09/26/2015 07:18 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429442#msg1429442">Quote from: rfmwguy on 09/25/2015 05:02 AM</a>
NSF-1701 Update - Flight Test 2B is now available to view.
...
https://youtu.be/HPm2oPUPi2Q

Excellent work! Stable setup and great sensitivity. The video makes results very credible.

Forgive the cheap arm-chair quarterbacking-

Isn't the filament hot (at high-voltage)? what good does using a stiff 500kV cable do, when the opposite end of a low-resistance filament its connected to, is connected to a (lower-voltage) rated wire pair, 1/2 of which is at ground?

It appears obvious that the plotted air-thermal is stopped when the magnetron kicks on. However, it occurs to me, that if a chimney effect is occurring, that energy that was heating the magnetron could be being diverted to heat the frustrum, and diverting momentum from the thermal air current. Perhaps a simple test is simply inverting the frustrum.

And, as Traveler stated, would be very nice to know the tuning and Q of the cavity. From what I've read about wire mesh waveguides having 10 x the attenuation of solid, I'll be surprised if the Q is over 500. I'd swag 300.

Apologize for the cheap critique on a great job well done! Thank's a lot!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: mwvp on 09/26/2015 07:34 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429433#msg1429433">Quote from: TheTraveller on 09/25/2015 04:04 AM</a>
Recent email corro with Roger Shawyer.

So as Roger explains in his latest patent application, the main Force is generated AFTER the Rf injection is switched off. Why? Because after the Rf pulse stops, the cavity Q doubles as it can now operate in an unloaded mode.

I would think, that unless he's using an RF relay or switch, the same impedance of the feed guide is still present, loading the cavity.

Several pages back concern was expressed over a changing impedance of the cavity as it "rings up". That is what a quarter-wave, or resonant matching section is for; a quarter wave (or multiple thereof) has the wonderful ability to match impedance.

Quote
> I'm home again, recovering from the effects of the super bug I picked up in
> hospital. Have a deep wound, caused by the super bug

Uh oh, very sorry to hear that. There is a cure:
http://edition.cnn.com/2015/03/31/health/anglo-saxon-potion-mrsa/

I take garlic often, and colloidal silver, which Nasa has now decided is OK for water filtration on the ISS.

Don't know where to find Ox-gall.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/26/2015 11:06 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429800#msg1429800">Quote from: mwvp on 09/26/2015 07:34 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429433#msg1429433">Quote from: TheTraveller on 09/25/2015 04:04 AM</a>
Recent email corro with Roger Shawyer.

So as Roger explains in his latest patent application, the main Force is generated AFTER the Rf injection is switched off. Why? Because after the Rf pulse stops, the cavity Q doubles as it can now operate in an unloaded mode.

I would think, that unless he's using an RF relay or switch, the same impedance of the feed guide is still present, loading the cavity.

Several pages back concern was expressed over a changing impedance of the cavity as it "rings up". That is what a quarter-wave, or resonant matching section is for; a quarter wave (or multiple thereof) has the wonderful ability to match impedance.

Quote
> I'm home again, recovering from the effects of the super bug I picked up in
> hospital. Have a deep wound, caused by the super bug

Uh oh, very sorry to hear that. There is a cure:
http://edition.cnn.com/2015/03/31/health/anglo-saxon-potion-mrsa/

I take garlic often, and colloidal silver, which Nasa has now decided is OK for water filtration on the ISS.

Don't know where to find Ox-gall.

Thanks for the med ref. Will check it out.

At resonance, an empty cavity looks like a short to the Rf gen and will reflect / reject almost all the applied power. See attached.

As a maggie outputs a wide range of freqs, it will sense a different frustum / cavity load impedance, dependent on freq and amount of cavity fill that has happened at that freq and the amount of reflected power at each freq it outputs.

Really a dogs breakfast, especially if the Q is low / input bandwidth is wide.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zero123 on 09/26/2015 01:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429433#msg1429433">Quote from: TheTraveller on 09/25/2015 04:04 AM</a>
Recent email corro with Roger Shawyer.

There is a lot of real engineering information and solid answers in this exchange.

The difference between the loaded and unloaded Q Roger has shared with an ideal injection match is new information and is why I believe SPR are now doing pulsed injection as after the Rf injection period is over (and the associated injection caused phase distortion) the cavity is them able to form a non phase distorted resonant condition, doubling the cavity Q (going from loaded Q to unloaded Q) and Force generation.

Roger makes this clear in his statement about the Flight Thruster and how the Force generated matches the doubled unloaded Q and not the 1/2 lower loaded, Rf injection period Q.

So as Roger explains in his latest patent application, the main Force is generated AFTER the Rf injection is switched off. Why? Because after the Rf pulse stops, the cavity Q doubles as it can now operate in an unloaded mode.

Nice breadcrumbs Roger. You have answered a lot of my questions.

Thanks.

> Hi Roger,
>
> I'm home again, recovering from the effects of the super bug I picked up in
> hospital. Have a deep wound, caused by the super bug, where one of the
> robot arms entered by abdomen. Like a 2nd belly button. Docs want me to
> take it very gentle until it starts to naturally regrow. They don't want to
> close it up just yet, just to be sure to not close with some of the
> superbug bacteria still active inside. So for now I have a patch over my
> 2nd belly button and daily nurse visits.
>
> So some time before I'm allowed in my workshop. But not wasting the time.
>
> Most of the software for the Raspberry PI 2B based control & monitoring
> system has been written. Will have a high power 5GHz WiFi based USB
> connection for control & data logging from the rotary table to my laptop.
>
> Point of discussion with others, NSF and myself. How do you / SPR measure
> frustum bandwidth / Q? Do you use bandwidth at 3dB away from max S11 rtn
> loss dB freq (as Prof Yang does) or 3dBs from 0 dB ref level as
> Eagleworks / NSF do or do you guys use another method? Would prefer to
> measure Q as you guys do. Makes a massive difference in bandwidth, Q &
> projected Force generation.

> Hi TT
>
> Using a network analyser to determine the Q of a high Q cavity via S11 is
> quick but requires a good understanding of the effect of scan speed and
> detector bandwidth or the results can be wildly inaccurate.
>
> For the delivery data of space qualified equipment, a calibrated procedure
> using separate signal source and power meter was usually specified. This is
> the technique we have always used at SPR.
>
> The signal source is put on a slow sweep to allow a dwell time of at least
> 10X time constant at each measurement point. The internal cavity power is
> measured using a cavity wall mounted detector measuring at least 30dB down
> (a very short probe!) and a wide detection bandwidth. The data is processed
> to measure the bandwidth 3dB down from max power level for at least two
> scans, one in each direction. (they must agree or there is a drift error in
> the measurement).
>
> Hope this helps.
>
> Best regards
>
> Roger

> Hi Roger,
>
> Thanks.
>
> So you prefer 2 port S21 over 1 port S11 or is S11 ok if the scan speed is
> VERY slow?
>
> I do understand the need for a SLOW scan and the frustum fill time / TC
> factor. What you shared is in line with my understanding.
>
> May I share this information on NSF cause there are a few arm chair
> "experts" that are strongly saying to measure bandwidth 3dB from the rtn
> loss 0dB reference level, which to me is madness.

> Hi TT
>
> S11 measurements are complicated if a highly tuned input circuit is used. I have seen published measurements that are clearly the Q of the input circuit only.
>
> Note that all Q measurements are Loaded Q measurements, and strictly speaking, if a perfect match is achieved, the actual unloaded Q is twice the measured Q.
>
> There are endless papers on the complications of Q measurement which is why smart customers are very careful about deliverable test data.
>
> The thrust predicted by the Thrust equation assumes unloaded Q. The measured thrust for the Flight thruster was very close to the predicted thrust when twice the measured Q was used in the equation.
>
> The design was successfully sold to Boeing on the measured thrust data.
>
> Feel free to share my comments on your forum.
>
> Best regards
>
> Roger

So, does that mean he does 2 port measurement, contrary to what you were asserting in the beginning of the thread? Or am I misunderstanding this?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/26/2015 01:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429720#msg1429720">Quote from: rfmwguy on 09/25/2015 09:26 PM</a>
Reddit user True-Creek did a supurb job of tone-decoding magnetron hum (on) and matching it against a trace. Note pauses to lift, lift resume and downward deflection in the blue area (mag on) and white area (mag off). Some traces in the blue area looks like it was trying to form, but could not.

Here are several data points to consider for yourself:

"I just ran a screenshot of the video through ImageJ and a Java-plugin that extracts the column-wise maximum. I've also extracted the the humming from the magentron (235.5-240 Hz) but it needed some correction:

0ioKt7B.png

It looks much more convincing than the impression I got from the video. There are about N=12 full trials and in 10/12 trials there is no obvious lift. In 9/12 trials there were lifts shortly after they ended. In only 6 or 7 there were significant drops.

Edit: Here is the data of the graph, though not normalized but in the original aspect ratio: http://pastebin.com/raw.php?i=eM5rLVXy "  by true-creek on reddit/emdrive 9/25/15

data interpretation depends on your expectations sometimes.

Here's what I see on the tone matched graph and raw data.

1st magnetron on:  Drop starts before power on
2nd magnetron on:  Drop starts before power on
3rd magnetron on:  Drop starts before power on
4th magnetron on:  Drop starts before power on
5th magnetron on:  No drop
6th magnetron on:  No drop
7th magnetron on:  Drop starts at magnetron on
8th magnetron on:  No drop at magnetron on
9th magnetron on:  Drop starts at magnetron on
10th magnetron on:  No drop at magnetron on
11th magnetron on:  No drop at magnetron on
12th magnetron on:  Drop starts at magnetron on
13th magnetron on:  No drop at magnetron on

Depending on how you choose your drop point, this could be construed as totally random.

A linear regression fits the data with an R squared of .71

Using that to determine the residuals, it seems to be a good fit to an oscillation in the system with a period of approximately 9 data points of True-Creek's data.

That period is very close to the on-off timing of the magnetron.

1st derivative looks pattern free.  i.e. noisy.

At a minimum, I'd consider re-running with a longer on-off window.  The oscillation in the system could be overriding any signal.


I would call this test inconclusive. :(

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/26/2015 01:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429799#msg1429799">Quote from: mwvp on 09/26/2015 07:18 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429442#msg1429442">Quote from: rfmwguy on 09/25/2015 05:02 AM</a>
NSF-1701 Update - Flight Test 2B is now available to view.
...
https://youtu.be/HPm2oPUPi2Q

Excellent work! Stable setup and great sensitivity. The video makes results very credible.

Forgive the cheap arm-chair quarterbacking-

Isn't the filament hot (at high-voltage)? what good does using a stiff 500kV cable do, when the opposite end of a low-resistance filament its connected to, is connected to a (lower-voltage) rated wire pair, 1/2 of which is at ground?

It appears obvious that the plotted air-thermal is stopped when the magnetron kicks on. However, it occurs to me, that if a chimney effect is occurring, that energy that was heating the magnetron could be being diverted to heat the frustrum, and diverting momentum from the thermal air current. Perhaps a simple test is simply inverting the frustrum.

And, as Traveler stated, would be very nice to know the tuning and Q of the cavity. From what I've read about wire mesh waveguides having 10 x the attenuation of solid, I'll be surprised if the Q is over 500. I'd swag 300.

Apologize for the cheap critique on a great job well done! Thank's a lot!
Thanks. I mispoke in the video, the bias (4kV) is not 500kV but 50kV. Its the clear insulator and got it from McMaster Carr. The filament (white wire) is always hot, and the preheat refers to the mag tube and heatsink, not the filament. Good catch.

I believe you are right, the mesh will have lower Q than solid copper, but interestingly enough, I predict it will also have less surface resistance because of its smaller mass.

Shell volunteered to run the VNA sweep on NSF-1701. I'll be mailing it to her early next week minus the magnetron. Surprisingly, I survived all the testing with only one mag...I think the dimensions suggested to me by Mr T and Doc were the key to this. Since there was no dielectric puck at the small end, they suggested I increase the height from 9 to 10.2 inches. This makes total sense to me as dielectrics are designed to reduce space (K factor).

I am swagging below 1000 for Q as well. One of the disadvantages of mesh is deformation. The cone is imperfect, actually looks more trombone-bell like on one side. I decided to leave it as such, because some speculated that a trombone bell might produce a better result...so I went with it.

The pauses, drops (mag on) and immediate rise after mag off convinced me something is there. Think its important to look at more than drops since testing was done in air, with all the variables of heat chimneys and currents. Vacuum testing is the ultimate for professional labs. There, one should only look for "downward" or other movements at mag on. For me, mag off was just as important to look at.

I stuck with the balance beam with small end down, because I wanted to avoid rotary table vibrations and expense. For me, it was the logical choice to fight against lift, which turned out to be far more of a force that I ever imagined.

No apologies necessary. I find NSF to be a more professional group of posters, including skeptics who avoid name-calling, hyperbole and stubborn arrogance. Not such what Chris and Doc have done to create this environment, but I really appreciate it, this I tried to honor the experiment by partially naming it after this forum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/26/2015 01:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429832#msg1429832">Quote from: glennfish on 09/26/2015 01:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429720#msg1429720">Quote from: rfmwguy on 09/25/2015 09:26 PM</a>
Reddit user True-Creek did a supurb job of tone-decoding magnetron hum (on) and matching it against a trace. Note pauses to lift, lift resume and downward deflection in the blue area (mag on) and white area (mag off). Some traces in the blue area looks like it was trying to form, but could not.

Here are several data points to consider for yourself:

"I just ran a screenshot of the video through ImageJ and a Java-plugin that extracts the column-wise maximum. I've also extracted the the humming from the magentron (235.5-240 Hz) but it needed some correction:

0ioKt7B.png

It looks much more convincing than the impression I got from the video. There are about N=12 full trials and in 10/12 trials there is no obvious lift. In 9/12 trials there were lifts shortly after they ended. In only 6 or 7 there were significant drops.

Edit: Here is the data of the graph, though not normalized but in the original aspect ratio: http://pastebin.com/raw.php?i=eM5rLVXy "  by true-creek on reddit/emdrive 9/25/15

data interpretation depends on your expectations sometimes.

Here's what I see on the tone matched graph and raw data.

1st magnetron on:  Drop starts before power on
2nd magnetron on:  Drop starts before power on
3rd magnetron on:  Drop starts before power on
4th magnetron on:  Drop starts before power on
5th magnetron on:  No drop
6th magnetron on:  No drop
7th magnetron on:  Drop starts at magnetron on
8th magnetron on:  No drop at magnetron on
9th magnetron on:  Drop starts at magnetron on
10th magnetron on:  No drop at magnetron on
11th magnetron on:  No drop at magnetron on
12th magnetron on:  Drop starts at magnetron on
13th magnetron on:  No drop at magnetron on

Depending on how you choose your drop point, this could be construed as totally random.

A linear regression fits the data with an R squared of .71

Using that to determine the residuals, it seems to be a good fit to an oscillation in the system with a period of approximately 9 data points of True-Creek's data.

That period is very close to the on-off timing of the magnetron.

1st derivative looks pattern free.  i.e. noisy.

At a minimum, I'd consider re-running with a longer on-off window.  The oscillation in the system could be overriding any signal.


I would call this test inconclusive. :(
Be sure to look at the mag on data as pauses in lift (flattening of sustem oscillation), not just drop. Also, look at datapoints at mag off. Think you'll see stonger evidence in the mag off condition.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/26/2015 02:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429838#msg1429838">Quote from: rfmwguy on 09/26/2015 01:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429832#msg1429832">Quote from: glennfish on 09/26/2015 01:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429720#msg1429720">Quote from: rfmwguy on 09/25/2015 09:26 PM</a>
Reddit user True-Creek did a supurb job of tone-decoding magnetron hum (on) and matching it against a trace. Note pauses to lift, lift resume and downward deflection in the blue area (mag on) and white area (mag off). Some traces in the blue area looks like it was trying to form, but could not.

Here are several data points to consider for yourself:

"I just ran a screenshot of the video through ImageJ and a Java-plugin that extracts the column-wise maximum. I've also extracted the the humming from the magentron (235.5-240 Hz) but it needed some correction:

0ioKt7B.png

It looks much more convincing than the impression I got from the video. There are about N=12 full trials and in 10/12 trials there is no obvious lift. In 9/12 trials there were lifts shortly after they ended. In only 6 or 7 there were significant drops.

Edit: Here is the data of the graph, though not normalized but in the original aspect ratio: http://pastebin.com/raw.php?i=eM5rLVXy "  by true-creek on reddit/emdrive 9/25/15

data interpretation depends on your expectations sometimes.

Here's what I see on the tone matched graph and raw data.

1st magnetron on:  Drop starts before power on
2nd magnetron on:  Drop starts before power on
3rd magnetron on:  Drop starts before power on
4th magnetron on:  Drop starts before power on
5th magnetron on:  No drop
6th magnetron on:  No drop
7th magnetron on:  Drop starts at magnetron on
8th magnetron on:  No drop at magnetron on
9th magnetron on:  Drop starts at magnetron on
10th magnetron on:  No drop at magnetron on
11th magnetron on:  No drop at magnetron on
12th magnetron on:  Drop starts at magnetron on
13th magnetron on:  No drop at magnetron on

Depending on how you choose your drop point, this could be construed as totally random.

A linear regression fits the data with an R squared of .71

Using that to determine the residuals, it seems to be a good fit to an oscillation in the system with a period of approximately 9 data points of True-Creek's data.

That period is very close to the on-off timing of the magnetron.

1st derivative looks pattern free.  i.e. noisy.

At a minimum, I'd consider re-running with a longer on-off window.  The oscillation in the system could be overriding any signal.


I would call this test inconclusive. :(
Be sure to look at the mag on data as pauses in lift (flattening of sustem oscillation), not just drop. Also, look at datapoints at mag off. Think you'll see stonger evidence in the mag off condition.

I did.  :(

That's why the good lord invented residuals analysis.  Remove the trend and look for meaningful deviations from the trend.

In your first test, the residuals analysis clearly showed deltas associated with power on vs power off.  In this data I don't see any pattern.  :(

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/26/2015 02:38 PM
Before you box the drive up to send to me, are you planning to do one more test with the drive inverted 180 from this test?

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/26/2015 02:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429829#msg1429829">Quote from: zero123 on 09/26/2015 01:00 PM</a>
So, does that mean he does 2 port measurement, contrary to what you were asserting in the beginning of the thread? Or am I misunderstanding this?

As I read it, SPR don't use a VNA for their highly accurate loaded Q measurements but use a separate freq sweeper with programmable dwell time to allow the cavity fill to happen before moving to the next freq and a separate power meter with a min 30dB attenuator, fed by a sensor in the frustum side wall.

That said, Roger did say S11 1 port scans can be used, providing the sweep can be done in discrete steps and each step stopping / dwelling long enough for the cavity to do a 10 TC long fill. Don't know if any VNA can do a dwell at each sweep freq increment.

Do too fast a stepped sweep or a continuously varied freq sweep, with either setup, and you may get rubbish / miss the resonance peaks / dips as the cavity may not be given enough time to do a 5 TC long fill.

As I understand the fill issue, the above was just confirmation that cavity fill time MUST be taken into consideration when doing a resonance search / sweep..

Main point for me was SPR measure the cavity bandwidth and loaded Q 3dB away from the max rtn loss dB point or max power point and not 3dB from the 0dB ref level.

Another biggie was SPR's Force equation uses unloaded Q.

Another was in a properly measured cavity, the measured loaded Q is 50% of the unloaded Q.

BTW this is the 1st time I know of that SPR has disclosed how they measure cavity Q. We know Prof Yang used 3db from max S11 rtn loss dB for their measured Q because it is in her papers.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/26/2015 03:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429842#msg1429842">Quote from: SeeShells on 09/26/2015 02:38 PM</a>
Before you box the drive up to send to me, are you planning to do one more test with the drive inverted 180 from this test?

Shell
Everything is still as it was when I ended FT 2B the other night. I'll see how things go this evening. What I might do is another test run as is and then another inverted. I know people are scrambling for data as I am scrambling for a break.

Let me see how much ambition I have tonight. Am also working on an ethernet screen capture solution to the hokey camcorder to monitor routine.

Actually, I have so many more tests I could run, this could turn into a full time endeavor...an unpaid full time endeavor if you catch my drift.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/26/2015 04:28 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429832#msg1429832">Quote from: glennfish on 09/26/2015 01:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429720#msg1429720">Quote from: rfmwguy on 09/25/2015 09:26 PM</a>
Reddit user True-Creek did a supurb job of tone-decoding magnetron hum (on) and matching it against a trace. Note pauses to lift, lift resume and downward deflection in the blue area (mag on) and white area (mag off). Some traces in the blue area looks like it was trying to form, but could not.

Here are several data points to consider for yourself:

"I just ran a screenshot of the video through ImageJ and a Java-plugin that extracts the column-wise maximum. I've also extracted the the humming from the magentron (235.5-240 Hz) but it needed some correction:

0ioKt7B.png

It looks much more convincing than the impression I got from the video. There are about N=12 full trials and in 10/12 trials there is no obvious lift. In 9/12 trials there were lifts shortly after they ended. In only 6 or 7 there were significant drops.

Edit: Here is the data of the graph, though not normalized but in the original aspect ratio: http://pastebin.com/raw.php?i=eM5rLVXy "  by true-creek on reddit/emdrive 9/25/15

data interpretation depends on your expectations sometimes.

Here's what I see on the tone matched graph and raw data.

1st magnetron on:  Drop starts before power on
2nd magnetron on:  Drop starts before power on
3rd magnetron on:  Drop starts before power on
4th magnetron on:  Drop starts before power on
5th magnetron on:  No drop
6th magnetron on:  No drop
7th magnetron on:  Drop starts at magnetron on
8th magnetron on:  No drop at magnetron on
9th magnetron on:  Drop starts at magnetron on
10th magnetron on:  No drop at magnetron on
11th magnetron on:  No drop at magnetron on
12th magnetron on:  Drop starts at magnetron on
13th magnetron on:  No drop at magnetron on

Depending on how you choose your drop point, this could be construed as totally random.

A linear regression fits the data with an R squared of .71

Using that to determine the residuals, it seems to be a good fit to an oscillation in the system with a period of approximately 9 data points of True-Creek's data.

That period is very close to the on-off timing of the magnetron.

1st derivative looks pattern free.  i.e. noisy.

At a minimum, I'd consider re-running with a longer on-off window.  The oscillation in the system could be overriding any signal.


I would call this test inconclusive. :(

Isn't the sampling rate of the chart something abysmally like one reading every 1.25 seconds?   Strikes me that the problem might be in synching the audio feed to the chart.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/26/2015 04:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429852#msg1429852">Quote from: rfmwguy on 09/26/2015 03:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429842#msg1429842">Quote from: SeeShells on 09/26/2015 02:38 PM</a>
Before you box the drive up to send to me, are you planning to do one more test with the drive inverted 180 from this test?

Shell
Everything is still as it was when I ended FT 2B the other night. I'll see how things go this evening. What I might do is another test run as is and then another inverted. I know people are scrambling for data as I am scrambling for a break.

Let me see how much ambition I have tonight. Am also working on an ethernet screen capture solution to the hokey camcorder to monitor routine.

Actually, I have so many more tests I could run, this could turn into a full time endeavor...an unpaid full time endeavor if you catch my drift.

It's your call and honestly you have done so much and all I was wondering if you were going to do just one more test run not if you were going to make this a low paying job. ;)

I can understand how it has to impact on your lack of home and personal life, it's your call and I'll support you no matter what.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/26/2015 05:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429797#msg1429797">Quote from: mwvp on 09/26/2015 07:02 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429316#msg1429316">Quote from: SeeShells on 09/24/2015 11:07 PM</a>
Areo and I got the dual opposing waveguides working, wasn't sure what we would see but I hoped for a symmetrical mode generation and there was. Taking a slices of time through the CE  frustum it is apparent that there are at least 2 modes overlaying each other.

That's the kind of traveling wave I expected to see. Very nice! Would like to see the outline/dimensions of the cavity and feed waveguide.
Still a work in progress VP, not quite ready to throw out here yet. Thanks.

Shell

speeelind

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/26/2015 06:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429843#msg1429843">Quote from: TheTraveller on 09/26/2015 02:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429829#msg1429829">Quote from: zero123 on 09/26/2015 01:00 PM</a>
So, does that mean he does 2 port measurement, contrary to what you were asserting in the beginning of the thread? Or am I misunderstanding this?

As I read it, SPR don't use a VNA for their highly accurate loaded Q measurements but use a separate freq sweeper with programmable dwell time to allow the cavity fill to happen before moving to the next freq and a separate power meter with a min 30dB attenuator, fed by a sensor in the frustum side wall.

That said, Roger did say S11 1 port scans can be used, providing the sweep can be done in discrete steps and each step stopping / dwelling long enough for the cavity to do a 10 TC long fill. Don't know if any VNA can do a dwell at each sweep freq increment.

Do too fast a stepped sweep or a continuously varied freq sweep, with either setup, and you may get rubbish / miss the resonance peaks / dips as the cavity may not be given enough time to do a 5 TC long fill.

As I understand the fill issue, the above was just confirmation that cavity fill time MUST be taken into consideration when doing a resonance search / sweep..

Main point for me was SPR measure the cavity bandwidth and loaded Q 3dB away from the max rtn loss dB point or max power point and not 3dB from the 0dB ref level.

Another biggie was SPR's Force equation uses unloaded Q.

Another was in a properly measured cavity, the measured loaded Q is 50% of the unloaded Q.

BTW this is the 1st time I know of that SPR has disclosed how they measure cavity Q. We know Prof Yang used 3db from max S11 rtn loss dB for their measured Q because it is in her papers.
Using a commercial VNA from well known companies there is NO problem with this kind of measurements. You can choose the sweep-time as well as a discrete frequency, applying averaging or what you like. However the used PLL dictate the min. possible frequency steps.
Via GPIB interface and labview for example you can do automated runs for whatever as long as you like for every frequency step.
If a good VNA is available there is no need for a separate generator and a spectrum analyzer, this configuration don't produce the (helpful)phase information,it gives only the magnitude of the signal.
For measurement the values of the whole circuit (transmission line, antenna feed, antenna, cavity,...)  i would use the network analyzer.

They may use this configuration for the signal tracking and tuning mechanism(needed caused by thermal variations)  through the run..

http://www.k0bg.com/myths.html
please take a look at "The SWR vs. Resonance Myth"

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/26/2015 07:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429840#msg1429840">Quote from: glennfish on 09/26/2015 02:12 PM</a>
I did.  :(

That's why the good lord invented residuals analysis.  Remove the trend and look for meaningful deviations from the trend.

In your first test, the residuals analysis clearly showed deltas associated with power on vs power off.  In this data I don't see any pattern.  :(

How are you able to calculate the first derivative like that @glennfish?  Are you using some software to convert the image of the interferometer trace into a spreadsheet file like .csv?  If so, maybe you could upload the data file to the forum here? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 09/26/2015 08:24 PM
Would someone so kind to share the magnetron sound analyze data for the 729 data points (of rfmwguy's last run)in the format of 1 for on, 0 for off please?

Fits this table: http://pastebin.com/raw.php?i=eM5rLVXy
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/26/2015 08:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429840#msg1429840">Quote from: glennfish on 09/26/2015 02:12 PM</a>

In your first test, the residuals analysis clearly showed deltas associated with power on vs power off.  In this data I don't see any pattern.  :(

Can you give me more information on what exactly I'm seeing and how the chart was put together?  Two things strike me.  First, the blue lines for magnetron on might have been done via photoshop/gimp and might not line up perfectly with the on/off cycle.  Is the red line at the bottom of the chart the audio?

Secondly, what time units is this chart in?  We could very well deal with an effect that is photonic in nature being recorded by a device taking measurements every 3ms / 0.003 seconds (how often does the LDS take a measurement).  Assuming that the audio recording station is 10 meters away from the device, it would take about 0.03 seconds (10/340) for the sound from the magnetron to reach the recording device, and that's assuming that the sound immediately starts propagating outward on turn on.  Combine that with not knowing how often the charting software is taking a reading or how it is coming up with that reading (input at time of reading or average over time) and I'd be very hesitant to say that I can pinpoint actual magnetron on with a high degree of accuracy. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Tellmeagain on 09/26/2015 08:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429852#msg1429852">Quote from: rfmwguy on 09/26/2015 03:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429842#msg1429842">Quote from: SeeShells on 09/26/2015 02:38 PM</a>
Before you box the drive up to send to me, are you planning to do one more test with the drive inverted 180 from this test?

Shell
Everything is still as it was when I ended FT 2B the other night. I'll see how things go this evening. What I might do is another test run as is and then another inverted. I know people are scrambling for data as I am scrambling for a break.

Let me see how much ambition I have tonight. Am also working on an ethernet screen capture solution to the hokey camcorder to monitor routine.

Actually, I have so many more tests I could run, this could turn into a full time endeavor...an unpaid full time endeavor if you catch my drift.

You might get a surprising result...[EDIT]What I want to say is, if you get forces in the same direction and with the same amplitude before and after the inversion, what you get is not a thrust... Look at the Dresden experiment. You need to take away systematic errors.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: JoeSteinregen on 09/26/2015 10:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429909#msg1429909">Quote from: X_RaY on 09/26/2015 08:24 PM</a>
Would someone so kind to share the magnetron sound analyze data for the 729 data points (of rfmwguy's last run)in the format of 1 for on, 0 for off please?

Fits this table: http://pastebin.com/raw.php?i=eM5rLVXy

I'm the one who extracted this data from the video. I wasn't quite pleased with that result, so I redid the table and the magnetron on/off data:

http://pastebin.com/raw.php?i=kv9SiT7y

(r3XNnCU.png)

Perhaps someone can listen to the video closely and confirm that the starting and end points of the intervals are reasonably precise.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/26/2015 11:39 PM
Found the problem.

You have 240 (actually 236 I think) data points for a 3 minute run.

rfmwguy stated that his software only captures a data point every 1.5 seconds (120 datapoints). 

You have interpreted the computer extrapolating a smooth line between two points as actual data.

Conclusion: rfmwguy can you upload the raw files that you logged to NSF.  We need to see the actual recorded data to figure out what is going on here.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/27/2015 02:26 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429946#msg1429946">Quote from: SteveD on 09/26/2015 11:39 PM</a>
Found the problem.

You have 240 (actually 236 I think) data points for a 3 minute run.

rfmwguy stated that his software only captures a data point every 1.5 seconds (120 datapoints). 

You have interpreted the computer extrapolating a smooth line between two points as actual data.

Conclusion: rfmwguy can you upload the raw files that you logged to NSF.  We need to see the actual recorded data to figure out what is going on here.
Well. I must be nuts. I just recorded Flight Test 2C, a full 1 hour video before I tear down the test stand. Here's what I did (before I ran out of storage on my 16G SD card:

3 minute testing each at a preheated maggie at 30%, 50%, 70% and 20% power cycles which will show variations of beam oscillations and thermal lift. I determined that 50% is the best power cycle as it jumps out of the the natural beam oscillations, so look for this in the video.

70% is mostly lift, 20 and 30% are hard to extract from the beam oscillations. 20% barely held its own against thermal lift decay. So I learned something tonight: 50% is the best power cycle for distinction from lift and beam oscillation.

This will take me a while to render and upload, so I will have another long evening, but NSF-1701 Flight Test 2C is going to be uploaded tonight. It is a comprehensive 1 hour video, bit of a wait between power cycle tests, but I think everyone will get something out of it. Again, focus should probably be on the 50% power cycle runs.

I am trying to add as much data as I can...I heard people wanting more from me, so here it is. I'll post when its ready to view this PM.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/27/2015 02:31 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429969#msg1429969">Quote from: rfmwguy on 09/27/2015 02:26 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429946#msg1429946">Quote from: SteveD on 09/26/2015 11:39 PM</a>
Found the problem.

You have 240 (actually 236 I think) data points for a 3 minute run.

rfmwguy stated that his software only captures a data point every 1.5 seconds (120 datapoints). 

You have interpreted the computer extrapolating a smooth line between two points as actual data.

Conclusion: rfmwguy can you upload the raw files that you logged to NSF.  We need to see the actual recorded data to figure out what is going on here.
Well. I must be nuts.
Not nuts but a little Crazy Eddie. :D

Thank you for doing this rfmwguy. You're a heck of a builder and one good guy. I look forward to looking at the data.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/27/2015 02:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429972#msg1429972">Quote from: SeeShells on 09/27/2015 02:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429969#msg1429969">Quote from: rfmwguy on 09/27/2015 02:26 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429946#msg1429946">Quote from: SteveD on 09/26/2015 11:39 PM</a>
Found the problem.

You have 240 (actually 236 I think) data points for a 3 minute run.

rfmwguy stated that his software only captures a data point every 1.5 seconds (120 datapoints). 

You have interpreted the computer extrapolating a smooth line between two points as actual data.

Conclusion: rfmwguy can you upload the raw files that you logged to NSF.  We need to see the actual recorded data to figure out what is going on here.
Well. I must be nuts.
Not nuts but a little Crazy Eddie. :D

Thank you for doing this rfmwguy. You're a heck of a builder and one good guy. I look forward to looking at the data.

Shell
Rendered and 30% completed on youtube upload.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/27/2015 03:01 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429978#msg1429978">Quote from: rfmwguy on 09/27/2015 02:57 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429972#msg1429972">Quote from: SeeShells on 09/27/2015 02:31 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429969#msg1429969">Quote from: rfmwguy on 09/27/2015 02:26 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429946#msg1429946">Quote from: SteveD on 09/26/2015 11:39 PM</a>
Found the problem.

You have 240 (actually 236 I think) data points for a 3 minute run.

rfmwguy stated that his software only captures a data point every 1.5 seconds (120 datapoints). 

You have interpreted the computer extrapolating a smooth line between two points as actual data.

Conclusion: rfmwguy can you upload the raw files that you logged to NSF.  We need to see the actual recorded data to figure out what is going on here.
Well. I must be nuts.
Not nuts but a little Crazy Eddie. :D

Thank you for doing this rfmwguy. You're a heck of a builder and one good guy. I look forward to looking at the data.

Shell
Rendered and 30% completed on youtube upload.
https://www.youtube.com/watch?v=zHIVeWhCMU8

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/27/2015 03:29 AM
Flight Test 2C ready to view. Due to the length (1 hour), the video quality is low.

https://youtu.be/J0JtHqG5cPc
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: original_mds on 09/27/2015 03:35 AM
Have any meep runs assumed a non-perfect geometry?  I'm thinking some of the radial cycling shown in some of the gifs may be an artifact from assuming a perfectly circular frustrum .  Would it still "spin" if the frustrum was modeled as slightly out of round, thus giving the modes a way to "lock"  to a particular orientation?  Same idea applies to the end caps and whether they are tilted relative to the barrel instead of perfectly aligned.

How difficult would it be to try adding small deformities  to the model, e.g. 0.1% out of round and 0.1% tilt of the end caps (not tilted in the same direction)?  This could help provide insight about how sensitive the system performance is to real-world variation.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: JoeSteinregen on 09/27/2015 10:30 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429946#msg1429946">Quote from: SteveD on 09/26/2015 11:39 PM</a>
Found the problem. You have 240 (actually 236 I think) instead of 120 data points for the 3 minute run.

Upsampling a signal is no information loss.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/27/2015 12:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429933#msg1429933">Quote from: JoeSteinregen on 09/26/2015 10:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429909#msg1429909">Quote from: X_RaY on 09/26/2015 08:24 PM</a>
Would someone so kind to share the magnetron sound analyze data for the 729 data points (of rfmwguy's last run)in the format of 1 for on, 0 for off please?

Fits this table: http://pastebin.com/raw.php?i=eM5rLVXy

I'm the one who extracted this data from the video. I wasn't quite pleased with that result, so I redid the table and the magnetron on/off data:

http://pastebin.com/raw.php?i=kv9SiT7y

(r3XNnCU.png)

Perhaps someone can listen to the video closely and confirm that the starting and end points of the intervals are reasonably precise.

Not sure how you did the extract, but the raw #s are extremely valuable along with the on/off data.  Well done and thank you.  If you can do the new video, you'll be a hero.   :) 

There's something called a probit analysis which I haven't done yet, but it needs a tad more data points than 13 to be meaningful.  In this latest run there are enough data points to actually make a statistical claim of some kind.

my perfect data file would look like this, just as you did

time stamp         volts     magnetron
1                       4.1       0
2                       4.2       0
3                       4.1       1
...

anyway, if you do more, I'll work with what you offer. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/27/2015 01:37 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429933#msg1429933">Quote from: JoeSteinregen on 09/26/2015 10:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429909#msg1429909">Quote from: X_RaY on 09/26/2015 08:24 PM</a>
Would someone so kind to share the magnetron sound analyze data for the 729 data points (of rfmwguy's last run)in the format of 1 for on, 0 for off please?

Fits this table: http://pastebin.com/raw.php?i=eM5rLVXy

I'm the one who extracted this data from the video. I wasn't quite pleased with that result, so I redid the table and the magnetron on/off data:

http://pastebin.com/raw.php?i=kv9SiT7y

(r3XNnCU.png)

Perhaps someone can listen to the video closely and confirm that the starting and end points of the intervals are reasonably precise.

Using this data set  (thank you!!!!), there is something interesting that emerges.

Taking only the windows of the test, ignoring the no-power middle section.

Separating out the mag on / mag off data sets:

We have two graphs.  Both have very high R squared values for a linear regression.  .92 and .94 respectively.  It doesn't get much better than that for a linear fit.

Now here is the interesting thing.  Look at the slopes of the equations.

RFMWGUY was suggesting that the rate of lift slows down when the magnetron is on.

In fact, it does exactly that.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/27/2015 02:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429933#msg1429933">Quote from: JoeSteinregen on 09/26/2015 10:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429909#msg1429909">Quote from: X_RaY on 09/26/2015 08:24 PM</a>
Would someone so kind to share the magnetron sound analyze data for the 729 data points (of rfmwguy's last run)in the format of 1 for on, 0 for off please?

Fits this table: http://pastebin.com/raw.php?i=eM5rLVXy

I'm the one who extracted this data from the video. I wasn't quite pleased with that result, so I redid the table and the magnetron on/off data:

http://pastebin.com/raw.php?i=kv9SiT7y


Perhaps someone can listen to the video closely and confirm that the starting and end points of the intervals are reasonably precise.

Here's a way of visualizing the slope differences.  It's based on using the regression equations appropriate for the mag on / mag off mode.  It's not statistical, it's just a visual aid to seeing the differences.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: dumbo on 09/27/2015 02:55 PM
glennfish: So if I am understanding correctly, this basically confirms (in a statistically rigorous way) that we are seeing anomalous thrust in the 2C flight test?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/27/2015 03:07 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: dumbo on 09/27/2015 02:55 PM</a>
glennfish: So if I am understanding correctly, this basically confirms (in a statistically rigorous way) that we are seeing anomalous thrust in the 2C flight test?

This data was from the previous data run, not the one he did last night.

No.  Not statistically rigorous by any means at this point.

Statistically, it suggests that that with one data set, there were differences in RFMWGUY's device's "lift" rates depending on whether the magnetron was on or off.

There are only a dozen or so slope measurements at this time.  That's no where near enough to make a claim of statistical significance.

There needs to be a lot more data to make any claims.

What can be stated is that RFMWGUY stated that he observed a difference in lift rates depending on whether the magnatron was on or off.  Statistically speaking, he wasn't hallucinating that difference during that test sequence.

Any claim beyond that at this time is a stretch.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/27/2015 03:31 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430049#msg1430049">Quote from: glennfish on 09/27/2015 03:07 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: dumbo on 09/27/2015 02:55 PM</a>
glennfish: So if I am understanding correctly, this basically confirms (in a statistically rigorous way) that we are seeing anomalous thrust in the 2C flight test?

This data was from the previous data run, not the one he did last night.

No.  Not statistically rigorous by any means at this point.

Statistically, it suggests that that with one data set, there were differences in RFMWGUY's device's "lift" rates depending on whether the magnetron was on or off.

There are only a dozen or so slope measurements at this time.  That's no where near enough to make a claim of statistical significance.

There needs to be a lot more data to make any claims.

What can be stated is that RFMWGUY stated that he observed a difference in lift rates depending on whether the magnatron was on or off.  Statistically speaking, he wasn't hallucinating that difference during that test sequence.

Any claim beyond that at this time is a stretch.

Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/27/2015 03:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: aero on 09/27/2015 02:55 PM</a>


Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

re: 1.  I have no idea

re: 2.  RFMWGUY's 60 minute run last night may have sufficient data to have some significance.  It wasn't until JoeSteinregen posted his data that there was anything to look at.   I can't do what JoeSteinregen did, so we won't know until he, or someone else creates that data set.  However, even if we can demonstrate with a high confidence that statistically something is happening in his settup, that doesn't mean that there is anomolous thrust occuring.  It would only mean that with his apparatus, things got different when the magnetron is on.

If I put on my methodology hat, there are so many issues in the experimental design that collectively it's amazing that there are any interesting results at all.   All statistics can do is give a probability that a difference exists.  It says nothing about why the difference exists.  In a proper experimental design, you state your hypothesis and select your measurement and analysis method before you turn on the power.  In this case, finding an interesting statistic after performing the experiment would have gotten me thrown out of gradschool.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/27/2015 04:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430023#msg1430023">Quote from: JoeSteinregen on 09/27/2015 10:30 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1429946#msg1429946">Quote from: SteveD on 09/26/2015 11:39 PM</a>
Found the problem. You have 240 (actually 236 I think) instead of 120 data points for the 3 minute run.

Upsampling a signal is no information loss.

Turn on takes place between data point 1 and data point 2.  The computer drawsa sloping line between the two points.  You sample data point 1.5 between points 1 and 2.  The device has not yet been turned on.  Because the computer does not know when turn on occurs it produces a line that begins to slope immediately after data point 1 and runs through point 1.5.  The result is it looks like the drop began before turn on.  If you simply had two points and no line you would see point, turn on, next point drop.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: JoeSteinregen on 09/27/2015 04:47 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430065#msg1430065">Quote from: SteveD on 09/27/2015 04:02 PM</a>
Turn on takes place between data point 1 and data point 2.  The computer drawsa sloping line between the two points.  You sample data point 1.5 between points 1 and 2.  The device has not yet been turned on.  Because the computer does not know when turn on occurs it produces a line that begins to slope immediately after data point 1 and runs through point 1.5.  The result is it looks like the drop began before turn on.  If you simply had two points and no line you would see point, turn on, next point drop.

Oh, you are right of course. I stand corrected. One would have to apply an uncertainty of 236/120≈1,97 time steps to the magnetron state data then. That would be good anyway since the audio track of the video could be slightly off.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Devilstower on 09/27/2015 06:02 PM
That there is a slight spike immediately before several of the "buzz periods" suggests that the audible hum doesn't perfectly align with the production of energy. It may be that the audio track is slightly behind the video. It may also be that, rather than having the slab-sided waveform suggested by the audio, the actual production of energy from the magnetron involves a ramp-up, ramp-down period with the hum representing only a portion of the energized period.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cosmo on 09/27/2015 07:18 PM
Forgive me if already answered by rfmwguy, but is the data logged at an interval faster than the ~1.25 second display update rate?  If so, what is the logging rate?  Since the data acquisition hardware probably has multiple inputs, why not add a simple current sensor to monitor the magnetron drive and run a test?  That way, the data for the magnetron drive is time correlated without having to manually guess based on the audio what is going on.  If logging is faster than the display update rate, even better!
Kurt
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/27/2015 08:15 PM
NSF-1701 Update - Flight Test 2D test data is attached. It is a spreadsheet with over 2700 time stamped data points. The LDS sensor voltage is on Channel 1. Unfortunately, I did not have enough time to make Channel 2 a mag on/off channel, so I will be uploading a video that displays the test stands computer (windows) clock. When you hear the hum, the mag is on, so mark it on the spreadsheet next to system time, which is synched.

There are two, 10 minutes tests at 50% power cycle that starts from cold, not preheated. Take a look at the attached spreadsheet and be ready to plug in the mag on and off markers once you view the video.

I hope this helps everyone out. I know there are some fantastic brain trusts out here that do far better with data analysis than I could. Enjoy. I'll post a link to the video soon.

Here is the video link, it is about 40% uploaded and will be viewable soon:

https://youtu.be/djhxm1Ep12I

Dave
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/27/2015 09:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430137#msg1430137">Quote from: rfmwguy on 09/27/2015 08:15 PM</a>
NSF-1701 Update - Flight Test 2D test data is attached. It is a spreadsheet with over 2700 time stamped data points. The LDS sensor voltage is on Channel 1. Unfortunately, I did not have enough time to make Channel 2 a mag on/off channel, so I will be uploading a video that displays the test stands computer (windows) clock. When you hear the hum, the mag is on, so mark it on the spreadsheet next to system time, which is synched.

There are two, 10 minutes tests at 50% power cycle that starts from cold, not preheated. Take a look at the attached spreadsheet and be ready to plug in the mag on and off markers once you view the video.

I hope this helps everyone out. I know there are some fantastic brain trusts out here that do far better with data analysis than I could. Enjoy. I'll post a link to the video soon.

Here is the video link, it is about 40% uploaded and will be viewable soon:

https://youtu.be/djhxm1Ep12I

Dave

Now how did you get such a sweet oscillation in there?

Folks I need some help.  My stat package nicely produces a 6th order polynomial fit to the data with an R squared north of .97.   That's good, so a residuals analysis will be easy...

EXCEPT...

My stat package seems to think that it doesn't have to give more that the most significant digit when it switches to exponential mode.  That makes the analysis difficult (there is a way, but I was planning other things today).

Does anyone have the ability to get a half dozen digits after the decimal on a 6th order polynomial regression.

Here's what I get:  y = -2E-18x^6 + 1E-14x^5 - 5E-11x^4 + 6E-08x^3 - 3E-05x^2 + 0.0032x + 6.8491

x is the row number starting with 1, blowing away the first 149 data points.

If anyone can get me the lots more digits on the first 5 coefficients, I'd be grateful.  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/27/2015 09:29 PM
Am I right that this data is going to be inverted so that movement up causes the beam to get closer to the sensor, causing the chart to move down?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: AnalogMan on 09/27/2015 10:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430163#msg1430163">Quote from: glennfish on 09/27/2015 09:27 PM</a>

EXCEPT...

My stat package seems to think that it doesn't have to give more that the most significant digit when it switches to exponential mode.  That makes the analysis difficult (there is a way, but I was planning other things today).

Does anyone have the ability to get a half dozen digits after the decimal on a 6th order polynomial regression.

Here's what I get:  y = -2E-18x^6 + 1E-14x^5 - 5E-11x^4 + 6E-08x^3 - 3E-05x^2 + 0.0032x + 6.8491

x is the row number starting with 1, blowing away the first 149 data points.

If anyone can get me the lots more digits on the first 5 coefficients, I'd be grateful.  :)

If you are using Excel then it is possible to show more significant digits:

I assume you have the trendline equation displayed on the chart.

• select the equation (surrounding box will be highlighted)
• right-click box and select "format trendline label ..." in the pop-up menu
• select "number" in the left-hand pane
• choose "scientific" in the category column
• increase the decimal places number to whatever you want
• close pop-up box and new format will be displayed on chart

Edit: added instructions

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/27/2015 10:43 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430164#msg1430164">Quote from: SteveD on 09/27/2015 09:29 PM</a>
Am I right that this data is going to be inverted so that movement up causes the beam to get closer to the sensor, causing the chart to move down?
Yes, lift will cause the LDS voltage to drop.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/27/2015 10:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430099#msg1430099">Quote from: Devilstower on 09/27/2015 06:02 PM</a>
That there is a slight spike immediately before several of the "buzz periods" suggests that the audible hum doesn't perfectly align with the production of energy. It may be that the audio track is slightly behind the video. It may also be that, rather than having the slab-sided waveform suggested by the audio, the actual production of energy from the magnetron involves a ramp-up, ramp-down period with the hum representing only a portion of the energized period.
Very good call. I noticed that the leakage meter never went off instantly when the hum started, meaning there has to be some sort of buildup. This makes deciding when to indicate "on" might be best done with a diode detector rather than hum start. Regardless, the voltage applied gives us a general "on" condition.

Future builders might come back with another way to measure, such as forward or reflected power measurements, current sensing, etc. Will be fun to watch the experiments down the road.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 01:06 AM
Kinda quiet out here tonight so I'll add that it took me about 3 hours to take everything down and park my 73 olds in the garage tonight. Just in time to turn on the TV...and find absolutely nothing of interest :o
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 01:37 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430180#msg1430180">Quote from: AnalogMan on 09/27/2015 10:29 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430163#msg1430163">Quote from: glennfish on 09/27/2015 09:27 PM</a>

EXCEPT...

My stat package seems to think that it doesn't have to give more that the most significant digit when it switches to exponential mode.  That makes the analysis difficult (there is a way, but I was planning other things today).

Does anyone have the ability to get a half dozen digits after the decimal on a 6th order polynomial regression.

Here's what I get:  y = -2E-18x^6 + 1E-14x^5 - 5E-11x^4 + 6E-08x^3 - 3E-05x^2 + 0.0032x + 6.8491

x is the row number starting with 1, blowing away the first 149 data points.

If anyone can get me the lots more digits on the first 5 coefficients, I'd be grateful.  :)

If you are using Excel then it is possible to show more significant digits:

I assume you have the trendline equation displayed on the chart.

• select the equation (surrounding box will be highlighted)
• right-click box and select "format trendline label ..." in the pop-up menu
• select "number" in the left-hand pane
• choose "scientific" in the category column
• increase the decimal places number to whatever you want
• close pop-up box and new format will be displayed on chart

Edit: added instructions

yep got that done.  Your advice was nuts on.

NOW the issue is, it turns out a 10th degree polynomial is a better fit.  Working that issue now.

Residuals show definite oscillatory behavior.  Hoping someone else can find the audio on - off so I don't have to think harder.  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/28/2015 02:44 AM
I would like to ask the members of the forum for some input/opinions.

Some of you know me from my posts on various RF and microwave issues.   I am just now starting a DIY emdrive test effort – I am finally getting my workshop back on line following a move –and I want to try to build on the outstanding work of SeeShell, rfmwguy, and others to hopefully make some small contribution of my own.

Anyway – to the request.

There are a multitude of test environment design factors of course and this is just a start but in order to begin limiting the possible test space I have narrowed down overall test configurations to the following:

1.   Rotary Table configuration – unit under test (UUT) thrusting either posigrade or retrograde to rotation
2.   Linear (slide) configuration – air or other low friction surface.   UUT thrusting along the access of the slide.
3.   Balance Beam (ala rfmwguy and seeshells)  UUT thrusting either up or down

In my thinking all have things going for them as well as potential problems, but I would like to ask for  your thoughts on each configurations.   In particular these are the things I have been considering:

•   Overall Pros and Cons
•   Challenges to getting usable data output
•   Potential systemic and situational error sources
•   Data which should/can be measured for either signal or noise/error determinations

ANYTHING else you can think of –

Thanks in advance.   If you would prefer to reply by private message rather than on the forum that is fine with me however please indicate any information which you do not want disseminated further.

Herman

PS – for those who don’t know me and  to provide some credibility background  - I have worked in both professionally and DIY settings on RF from LF to 40+ Ghz, high power RF and RF power supplies, vacuum chambers and systems, nuclear power plants  and various and sundry other technical fields including aerospace and defense for the past 39 years.  Well acquainted with safety procedures - wrote some for my last company. This will be my first big retirement project and I can’t wait to get started. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: JoeSteinregen on 09/28/2015 12:02 PM
I've added the magnetron data via frequency analysis (using ffmpeg, Audacity for sample rate conversion and visualization and the R packages tuneR, signal and mmand for the actual work). Everything worked fine except for a propeller plane that was humming at 240 Hz as well, so that needed some editing. :) I hope it fits the video data well. I've only checked the first and last sample.

(ZvdMRbH.png)

ZvdMRbH.png

http://pastebin.com/raw.php?i=JPRBS1YF
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: transistorboy32 on 09/28/2015 12:07 PM
I took a shot at doctoring up rfmwguy's excel file for NSF-1701 Flight Test #2D. I first figured out when the video starts in realtime (15:22:28) and added a column to indicate the video timestamp for each sample. I then noted down a few events (such as test begin/end and when the 50mg weight is dropped at the end), as well as the times I heard the magnetron turning on & off (to the nearest second). Note, I'm no Excel guru, so hopefully what I've done can be read & understood.

It sounds like the mag hums a little differently about 5 seconds after it's turned on each time, especially when it's cold. This effect seems to diminish the warmer it gets.  Therefore, I also added a "shifted" column which is the same as the regular mag on/off times, except I marked each mag on cycle about 5 seconds after the mag actually turns on. If the mag needs to hunt for ~5 seconds before locking on frequency (or something), then this column should help to ignore it. (The shifted numbers count the mag as off for the first 5 seconds of each on cycle, to try to ignore possible 'resonance seeking' issues.)

Also note: at 50% power, there's 15 seconds of On time to 10 seconds of Off time. Maybe the microwave manufacturers knew the mag takes 5 seconds to 'warm up' each time and therefore it actually ends up being ~10 seconds On, ignoring the warm-up for the first 5 seconds of each cycle. It might be worth a quick test to see if there's always 5 seconds more On time than there should be with any given power level.

I totaled up the On and Off times for both tests, and for both 'straight' cycles and 'shifted' cycles.

Note: Voltage increases as the frustum moves DOWN.

Test #1 (mag starts @ room temp):
Sum delta volts ON (modified): -1.02295
Sum delta volts OFF (modified): -0.93384
Sum delta volts ON (straight): -1.35498
Sum delta volts OFF (straight): -0.57251

Test #2 (mag starts warm, not hot/cold):
Sum delta volts ON (modified): -0.37964
Sum delta volts OFF (modified): -0.64941
Sum delta volts ON (straight): -0.58716
Sum delta volts OFF (straight): -0.42603

I think, to verify downwards thrust, the sums when ON should be smaller in magnitude than the sums when OFF. In other words, the beam should deflect less when the mag is on than when it is off. Heating will cause the beam to rise regardless, but it should rise less quickly when the mag is on if it is indeed producing downwards thrust. However, the effects of heating are also increased when the mag is on. It looks like it really depends on thermal mass characteristics of the setup. Obviously the mag doesn't instantly heat up or cool down each time it's toggled on/off, and the time it takes to do so seems to be at least partially masking possible thrust effects here. How long does it take for the 'heat chimney' to start taking effect and at what rate does it occur? If it was on the order of minutes or on the order of a second or two, it would be easier to filter out. However, it looks like it takes about the same amount of time as the mags' 25 second cycle time, which makes it really difficult to pin down. That and/or the beam's natural oscillation period. Seems like a vertically-oriented setup like this makes it pretty tough to extract such data.

On a related note, in reply to graybeardsyseng's question: to me it looks like most/any vertical setup using an attached magnetron will make it tough to filter out thermal/heat rising effects - I'd look into other orientations, or use a detached RF source, etc. That's just my thought after looking at the data for NSF-1701's latest test.

As you can see, the only time delta On is less than delta Off is in test #2, when the mag starts 'warm', and only when looking at the shifted numbers where the first 5 seconds of each mag on cycle aren't counted. That makes sense if the effects of heating overpower any thrust as the mag heats up. If I extracted the numbers correctly, it looks like both tests start with a moderate amount of displacement, then during the middle of the test displacement per cycle peaks, and then the last few cycles have little displacement at all. At the end of the tests the mag should be fully warmed up and any chimney effects should already have their flow paths well-established, etc. I'm sure there's things I'm missing here - I'll leave it up to others to think about for a while.

I tried to figure the beam displacement due to cooling during the time between tests. I arrived at a figure of 0.125177 volts per minute on average.

I also tried to figure the deflection caused by the 50mg weight dropped at the end of the video. However, I'm not sure at exactly what point rfmwguy drops the weight. If I listen closely it sounds like the drop is at 38:25, but looking at the voltage graph for that time, I notice a large discontinuity about 5 seconds later, at 38:30. I made the estimation for each time and came up with 0.085051 volts or 0.05201 volts (per 50mg), depending on when the drop actually occurs. Those numbers also take into consideration thermal cooling over the beam settling duration (caused by the weight drop), according to the previous calculation (at least, as best as I could figure).

I think once SeeShell sets up her experiment it will be important to try several different cycle on/off times to uncover any otherwise hard-to-find time-delayed effects such as heat chimney forming.

I'll include my doctored up version of the spreadsheet. I wouldn't take any of my figures or estimations for fact until you go over my work in the file. I've been at this for the last several hours, and it's very possible I made a mistake along the way.

Thanks to rfmwguy for your amazing work! This has been a very exciting journey so far, even if I'm just lurking on the sidelines enjoying the progress & expertise of others.

-Seth
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 01:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>
I would like to ask the members of the forum for some input/opinions.

Some of you know me from my posts on various RF and microwave issues.   I am just now starting a DIY emdrive test effort – I am finally getting my workshop back on line following a move –and I want to try to build on the outstanding work of SeeShell, rfmwguy, and others to hopefully make some small contribution of my own.

Anyway – to the request.

There are a multitude of test environment design factors of course and this is just a start but in order to begin limiting the possible test space I have narrowed down overall test configurations to the following:

1.   Rotary Table configuration – unit under test (UUT) thrusting either posigrade or retrograde to rotation
2.   Linear (slide) configuration – air or other low friction surface.   UUT thrusting along the access of the slide.
3.   Balance Beam (ala rfmwguy and seeshells)  UUT thrusting either up or down

In my thinking all have things going for them as well as potential problems, but I would like to ask for  your thoughts on each configurations.   In particular these are the things I have been considering:

•   Overall Pros and Cons
•   Challenges to getting usable data output
•   Potential systemic and situational error sources
•   Data which should/can be measured for either signal or noise/error determinations

ANYTHING else you can think of –

Thanks in advance.   If you would prefer to reply by private message rather than on the forum that is fine with me however please indicate any information which you do not want disseminated further.

Herman

PS – for those who don’t know me and  to provide some credibility background  - I have worked in both professionally and DIY settings on RF from LF to 40+ Ghz, high power RF and RF power supplies, vacuum chambers and systems, nuclear power plants  and various and sundry other technical fields including aerospace and defense for the past 39 years.  Well acquainted with safety procedures - wrote some for my last company. This will be my first big retirement project and I can’t wait to get started. 
Yay! Welcome to the DIY world! Fear not, as I took a lot of the naysayer hits when I started posting a few months ago, so in a sense I've absorbed a lot of the pressure for those who follow  8)

I've thought long and hard about many of your questions. Rotary tables need an air source that will stir up all ambient air around the DUT. Same for a linear table. While I think horizontal measuring is best for ambient air measuring, the background artifacts can be a challenge.

Regarding vertical measurements, lift is an enemy, much more so that I would have thought, even with a wire mesh frustum. Extracting data out of the natural lift is difficult as you can see by the fine work done by data analysists here. I still think this is the way to go as it limits other mechanical and electrical variables.

Datalogging: suggest you go with a fast computer that can handle screen recording with ease. Datalogging is usually serial and even an old PC like mine handled it easily; not so with screen record. Quad core processor is a must. DAQ can be anything, but try to go with a 12 bit as a minumum. Locate several feet from frustum and power supplies.

Laser Displacement Sensors - highly recommend this for vertical measurements. Try to select a 40mm +/- 10mm range rather than a 100mm+ sensor. The closer, the better resolution...up to 7 digits. Try Omron or equivalent.

Setup in an area with no vents and cover windows for drafts. You can see the deflections as I simply approached the setup.

Have nothing else on AC lines feeding your gear that could draw a load (pretty basic advice).

Other than that, make sure you HAVE FUN. Thats really the bottom line Graybeard. We are here to help and support your efforts.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: RERT on 09/28/2015 01:46 PM
Rfmwguy -

I did a fourier series analysis of the test D data you posted, having been through the video to manually add the on/off periods of the magnetron.

The effect as in NSF1701 test 1, your initial test, persists: there is a signal correlated quite strongly with the magnetron in the first two-thirds of your first 10 minute test in test D. This is when the magnetron was cool. Later, the effect becomes much less pronounced.

I took the opportunity to analyse the cooling period when the magnetron was not running, by way of a control test. That gives us some hint as to what signals might be regarded as significant.

Though particularly the first part of the first test appears distinct, especially in the frequency domain, overall the scale of the effect is comparable to that in the control.

I think you would be hard-pushed to claim the data overall strongly supports the hypothesis of thrust. Perhaps the picture is consistent with that notion if you are losing resonance as the magnetron gets hot, but that's just a stab in the dark.

My analysis is attached. There are three charts in the first four tabs which illustrate the above conclusion.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 02:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430448#msg1430448">Quote from: RERT on 09/28/2015 01:46 PM</a>
Rfmwguy -

I did a fourier series analysis of the test D data you posted, having been through the video to manually add the on/off periods of the magnetron.

The effect as in NSF1701 test 1, your initial test, persists: there is a signal correlated quite strongly with the magnetron in the first two-thirds of your first 10 minute test in test D. This is when the magnetron was cool. Later, the effect becomes much less pronounced.

I took the opportunity to analyse the cooling period when the magnetron was not running, by way of a control test. That gives us some hint as to what signals might be regarded as significant.

Though particularly the first part of the first test appears distinct, especially in the frequency domain, overall the scale of the effect is comparable to that in the control.

I think you would be hard-pushed to claim the data overall strongly supports the hypothesis of thrust. Perhaps the picture is consistent with that notion if you are losing resonance as the magnetron gets hot, but that's just a stab in the dark.

My analysis is attached. There are three charts in the first four tabs which illustrate the above conclusion.

R.
Thanks so much for your analysis. It is especially insightful as a dampening of "force" change as temp increases which likely indicates a resonance shift of the frustum or frequency shift of the magnetron. This matches exactly what shawyer, nasa and perhaps Yang had commented on. In fact, some of the designs had tunable elements that changed resonance points as temp varied.

Therefore you have confirmed an overall hypothesis that a frustum and magnetron should be designed to either "tune on the fly" or be designed to resonate at a max, stabilized temperature. In my case, this was 200 deg C.

This, no doubt, will add to the body of knowledge moving forward. While my design was not tunable, it could have been designed specifically to resonate at a higher temp, what would be needed is a thermal chamber (or maybe an oven) with a way to monitor resonance at temp.

When Shell does the VNA sweep on the cold NSF-1701 frustum, it should probably clear this up. Again, great work and thanks for confirming a hypothesis that frustum/magnetron temp is a critical design element to consider in ambient air tests.

<edit> A bit of insight once I looked at your spreadsheet. The manufacturer establishes 50% power (heating) cycle not as 50% on/off, but an average of about 3 secs longer in the ON state; 14 secs compared to 11 secs on average. This may indicate a delayed response bedor mag generates any significant energy. This DOES match with my general observation that Leakage Meter did NOT immediately register energy, but audible warning was a few secs after hum began. Considering this is a manufacturer's design, I believe the delay is not due to frustum charging, but is natural magnetron characteristic...not instant energy firing into frustum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SlightPace on 09/28/2015 02:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>
I would like to ask the members of the forum for some input/opinions.

Some of you know me from my posts on various RF and microwave issues.   I am just now starting a DIY emdrive test effort – I am finally getting my workshop back on line following a move –and I want to try to build on the outstanding work of SeeShell, rfmwguy, and others to hopefully make some small contribution of my own.

Anyway – to the request.

There are a multitude of test environment design factors of course and this is just a start but in order to begin limiting the possible test space I have narrowed down overall test configurations to the following:

1.   Rotary Table configuration – unit under test (UUT) thrusting either posigrade or retrograde to rotation
2.   Linear (slide) configuration – air or other low friction surface.   UUT thrusting along the access of the slide.
3.   Balance Beam (ala rfmwguy and seeshells)  UUT thrusting either up or down

In my thinking all have things going for them as well as potential problems, but I would like to ask for  your thoughts on each configurations.   In particular these are the things I have been considering:

•   Overall Pros and Cons
•   Challenges to getting usable data output
•   Potential systemic and situational error sources
•   Data which should/can be measured for either signal or noise/error determinations

ANYTHING else you can think of –

Thanks in advance.   If you would prefer to reply by private message rather than on the forum that is fine with me however please indicate any information which you do not want disseminated further.

Herman

PS – for those who don’t know me and  to provide some credibility background  - I have worked in both professionally and DIY settings on RF from LF to 40+ Ghz, high power RF and RF power supplies, vacuum chambers and systems, nuclear power plants  and various and sundry other technical fields including aerospace and defense for the past 39 years.  Well acquainted with safety procedures - wrote some for my last company. This will be my first big retirement project and I can’t wait to get started. 

A rotary rig will allow unlimited contious accelleration (well, depending on friction in your rig) and therefore most likely a higher signal to noise ratio. It would also be easy to do control experiments like rotating the frustum 180 deg. for reverse thrust, or 90 degrees (pointing towards or away from the rotational axis) for zero thrust.
On the other hand, it will arguably be the most complicated setup to build.

Whichever configuration you choose, be very careful when you design your experiment. What is your hypothesis? How can you falsify it? What control experiments do you need? The most accurate measurements in the world won't save you if you don't know what it is you're measuring.
As I have mentioned earlier, in my opinion, the most important control experiment to do is one where you are knowingly injecting EM at a non-resonating frequency. That should be your "negative control" experiment. Naturally, this means you must know the resonant freq. of your cavity and so on.

It is of course also important that you do at least 3 independent repetitions of each experiment, the more the better.

Good luck!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: JoeSteinregen on 09/28/2015 02:52 PM
I just compared the my magnetron data with RERT's data and it never differed more than one data point, so both data sets are probably precise within ~383.5ms. The mouse clicks in the video match the audio track pretty closely, definitely within 100ms. I think with N=48 that shouldn't be a problem, but perhaps one should apply a sigma=242ms (0,32 time steps) gaussian kernel to the ON/OFF data. Not sure (I'm not a statistician).
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 03:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430409#msg1430409">Quote from: JoeSteinregen on 09/28/2015 12:02 PM</a>
I've added the magnetron data via frequency analysis (using ffmpeg, Audacity for sample rate conversion and visualization and the R packages tuneR, signal and mmand for the actual work). Everything worked fine except for a propeller plane that was humming at 240 Hz as well, so that needed some editing. :) I hope it fits the video data well. I've only checked the first and last sample.

(ZvdMRbH.png)

ZvdMRbH.png

http://pastebin.com/raw.php?i=JPRBS1YF
]

ok, some rudimentary statistics to the measurements.

Based on the previous observation that the slope was different between mag on vs mag off times:

1.  I broke the data into 47 pairs of data
       - pair 1 was the power on data
       - pair 2 was the power off data immediately following
2.  I calculated the linear regression slope for each pair of data
3.  I calculated if the on slope was greater than the off slope  (in this case all the data trends were down for the observations
4.  Assuming the probability of the slopes being < or > is 50/50, a simple binomial calculation shows

    Number of trials:  47
    Number of "successes":  27
    Probability that result is random:   0.069

   I have NOT normalized the time stamps which would produce different results.  Samples were as high as 2 per second and as low as 1 per second. On data was typically about 20 data points.  Off data was typically about 15 data points.  Not quite 50% cycling.  :)

I'll post the spreadsheet later.  I have to work for a living.  :(

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 04:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430060#msg1430060">Quote from: glennfish on 09/27/2015 03:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: aero on 09/27/2015 02:55 PM</a>


Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

...

If I put on my methodology hat, there are so many issues in the experimental design that collectively it's amazing that there are any interesting results at all.   All statistics can do is give a probability that a difference exists.  It says nothing about why the difference exists.  In a proper experimental design, you state your hypothesis and select your measurement and analysis method before you turn on the power.  In this case, finding an interesting statistic after performing the experiment would have gotten me thrown out of gradschool.

Thanks...this last paragraph had a lot of stopping power with me. Since I do not have an advanced degree in science, it took me a while for this to sink in. You are 100% correct. Classical scientific research states you cannot move forward without a hypothesis first.

It does beg the question, does this rule somehow limit potential discovery? I recall having this conversation many years ago, me being on the side of "try and find out" my engineering pal being on the side of rigorous adherance to classical methodology. We never resolved our "dispute" but its good to have this refreshed in our minds.

Had I followed canon, I would never have started my build, for I have no hypothesis on why this thing might work, I only know there was enough to spark my interest in trying...perhaps the classic scientific versus why not try argument might live on forever. :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Eer on 09/28/2015 04:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430537#msg1430537">Quote from: rfmwguy on 09/28/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430060#msg1430060">Quote from: glennfish on 09/27/2015 03:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: aero on 09/27/2015 02:55 PM</a>


Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

...

If I put on my methodology hat, there are so many issues in the experimental design that collectively it's amazing that there are any interesting results at all.   All statistics can do is give a probability that a difference exists.  It says nothing about why the difference exists.  In a proper experimental design, you state your hypothesis and select your measurement and analysis method before you turn on the power.  In this case, finding an interesting statistic after performing the experiment would have gotten me thrown out of gradschool.

Thanks...this last paragraph had a lot of stopping power with me. Since I do not have an advanced degree in science, it took me a while for this to sink in. You are 100% correct. Classical scientific research states you cannot move forward without a hypothesis first.

It does beg the question, does this rule somehow limit potential discovery? I recall having this conversation many years ago, me being on the side of "try and find out" my engineering pal being on the side of rigorous adherance to classical methodology. We never resolved our "dispute" but its good to have this refreshed in our minds.

Had I followed canon, I would never have started my build, for I have no hypothesis on why this thing might work, I only know there was enough to spark my interest in trying...perhaps the classic scientific versus why not try argument might live on forever. :o

Indeed - and had we waited for a comprehensive hypothesis as to why things fall to the ground, we'd still be waiting to discover gravity.

Perhaps, in the investigative stage, the experimental work is more akin to natural philosophy - observing nature and speculating about what it means that thus is so and why - as a natural preamble to more rigorous scientific analysis proving the hows and whys.

Nothing wrong with that.  Experiment on.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 04:15 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430537#msg1430537">Quote from: rfmwguy on 09/28/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430060#msg1430060">Quote from: glennfish on 09/27/2015 03:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: aero on 09/27/2015 02:55 PM</a>


Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

...

If I put on my methodology hat, there are so many issues in the experimental design that collectively it's amazing that there are any interesting results at all.   All statistics can do is give a probability that a difference exists.  It says nothing about why the difference exists.  In a proper experimental design, you state your hypothesis and select your measurement and analysis method before you turn on the power.  In this case, finding an interesting statistic after performing the experiment would have gotten me thrown out of gradschool.

Thanks...this last paragraph had a lot of stopping power with me. Since I do not have an advanced degree in science, it took me a while for this to sink in. You are 100% correct. Classical scientific research states you cannot move forward without a hypothesis first.

It does beg the question, does this rule somehow limit potential discovery? I recall having this conversation many years ago, me being on the side of "try and find out" my engineering pal being on the side of rigorous adherance to classical methodology. We never resolved our "dispute" but its good to have this refreshed in our minds.

Had I followed canon, I would never have started my build, for I have no hypothesis on why this thing might work, I only know there was enough to spark my interest in trying...perhaps the classic scientific versus why not try argument might live on forever. :o

I wouldn't "stop" .  The issue in science starts with observation, then classification, then experimental method.  Your first test data showed an observation of different slopes.  Methodologically, that leads to MY prediction that your next run would also show different slopes and in MY world I set up analysis to test that.  If you see my latest analysis, that was consistent with a proper methodology.  And, to your efforts, statistically suggestive that your hunches and methods are showing a real phenomenon.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 04:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430537#msg1430537">Quote from: rfmwguy on 09/28/2015 04:03 PM</a>
Thanks...this last paragraph had a lot of stopping power with me. Since I do not have an advanced degree in science, it took me a while for this to sink in. You are 100% correct. Classical scientific research states you cannot move forward without a hypothesis first.

It does beg the question, does this rule somehow limit potential discovery? I recall having this conversation many years ago, me being on the side of "try and find out" my engineering pal being on the side of rigorous adherance to classical methodology. We never resolved our "dispute" but its good to have this refreshed in our minds.

Had I followed canon, I would never have started my build, for I have no hypothesis on why this thing might work, I only know there was enough to spark my interest in trying...perhaps the classic scientific versus why not try argument might live on forever. :o

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430544#msg1430544">Quote from: Eer on 09/28/2015 04:12 PM</a>
Indeed - and had we waited for a comprehensive hypothesis as to why things fall to the ground, we'd still be waiting to discover gravity.

Perhaps, in the investigative stage, the experimental work is more akin to natural philosophy - observing nature and speculating about what it means that thus is so and why - as a natural preamble to more rigorous scientific analysis proving the hows and whys.

Nothing wrong with that.  Experiment on.

There is some misunderstanding of the meaning of hypothesis in the context of carrying out an experimental program.

It doesn't mean hypothesis as in "I think the emdrive works with virtual particles/ evanescent waves/ floobie dust", but rather "I believe that X is going to happen given Y".  In your case, your hypothesis would have been "I think the beam will deflect down given a voltage applied to the magenta".  That would have then defined your null hypothesis, which would be "there is statistically no difference in deflections between voltage on and voltage off".  Disproving this null hypothesis to some significance level (ie. there is only a z% chance that the results appeared to be non-null when they were in fact null) is therefore a proof of your hypothesis.

Having a theory of how the emdrive works, which seems to be what you're talking about, is irrelevant to whether or not you could formulate a statistical hypothesis for your experiment and and test that statistical hypothesis in a rigorous way.   

A hypothesis is just an expectation that can be falsified.  It doesn't have to explain the mechanisms of why it happened; that's a job for later experimental work.     

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 04:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430532#msg1430532">Quote from: glennfish on 09/28/2015 03:59 PM</a>

I'll post the spreadsheet later.  I have to work for a living.  :(

Here's the spreadsheet

SHEET:  raw2.php

Columns A-D were provided to me.  Column E is a flag I set to use or not use the data  "K" means keep, which represents the runs.

Button 1 is a VBA script that generates the data to the right:
    ON are the data observations where the magnetron is on
    OFF ar the data observations where the magnetron is off
    Row 2 has the linear regression for that data group, reporting only the slope of the equation

SHEET: Sheet1

Column A is the ON slope
Column B is the OFF slope immediately following
Column C is 0 if ON <= OFF or 1 if ON > OFF
summary in yellow

SHEET:  VBA CODE

VBA provided here.  This web site won't allow the upload of an .xlsm file type

Binomally calculated here:  http://stattrek.com/online-calculator/binomial.aspx

cumulative probability is probably the more accurate indicator.  Read the explanation before making assertions about "rigorous statistical analysis"  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 04:51 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430546#msg1430546">Quote from: glennfish on 09/28/2015 04:15 PM</a>
Methodologically, that leads to MY prediction that your next run would also show different slopes and in MY world I set up analysis to test that.  If you see my latest analysis, that was consistent with a proper methodology.  And, to your efforts, statistically suggestive that your hunches and methods are showing a real phenomenon.

Wait, what?

Are you referring to the first test or the second? 

You said:
Quote
Based on the previous observation that the slope was different between mag on vs mag off times:

1.  I broke the data into 47 pairs of data
       - pair 1 was the power on data
       - pair 2 was the power off data immediately following
2.  I calculated the linear regression slope for each pair of data
3.  I calculated if the on slope was greater than the off slope  (in this case all the data trends were down for the observations
4.  Assuming the probability of the slopes being < or > is 50/50, a simple binomial calculation shows

    Number of trials:  47
    Number of "successes":  27
    Probability that result is random:   0.069

So doesn't that mean that the second test wouldn't reject the null hypothesis that the mean slope of voltage on is no different that the mean slope of voltage off?

Instead of busting out the binomial theorem, it's easier (depending on your stats package) to just use the t-test.  It was built for looking at the means and variances of two different groups of data and then determining the probability that the means are actually the same.  If that probability is less than your significance level, you can reject your null hypothesis that there is no difference in voltage on vs voltage off (your 50/50 assumption).

In excel its just =ttest(array of slopes of mag on,array of slopes of mag off,1,3) 

As a side note, when you use this procedure on the first test, there is a statistically significant difference between mag on and mag off to a significance of about 2% (ie. there is only a 2% chance that the mean slopes are actually the same).  So the first test did indicate that mag on is different than mag off.  Whether that's from anomalous thrust or not is a question of systematics, not stats. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 05:04 PM
The data used was the most recent provided from yesterday with the mag-on/off coding provided this a.m.  Sorry to confuse that.

2nd, you're right about alternative statistical tests.  I had to stick to my simplest apriori assumption which was dirt simple.  Are the slopes different, yes or no?  :)   When you wear a methodology hat, you have to stick to what you said, even if it means you have to kick yourself in the head ten times because the real data suggests something different.

Your observations and suggestions are correct.   There's a slug of other things we can throw at this too many perhaps :), t test among them.  I haven't had the time today for more than a rudimentary look.

re the null hypothesis, that would in this case be  "The slopes are not different between power on vs power off states".  The null hypothesis appears to be in jeopardy.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 05:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430580#msg1430580">Quote from: glennfish on 09/28/2015 05:04 PM</a>
The data used was the most recent provided from yesterday with the mag-on/off coding provided this a.m.  Sorry to confuse that.

2nd, you're right about alternative statistical tests.  I had to stick to my simplest apriori assumption which was dirt simple.  Are the slopes different, yes or no?  :)   When you wear a methodology hat, you have to stick to what you said, even if it means you have to kick yourself in the head ten times because the real data suggests something different.

Your observations and suggestions are correct.   There's a slug of other things we can throw at this too many perhaps :), t test among them.  I haven't had the time today for more than a rudimentary look.

re the null hypothesis, that would in this case be  "The slopes are not different between power on vs power off states".  The null hypothesis appears to be in jeopardy.

I just did the t-test to the excel sheet you added.  You can see it in Sheet1 right next to the data columns, starting in cell E3.  I highlighted in green the two most important stats to note, namely the one-tailed and two-tailed probabilities that the means of mag on and mag off are actually the same (ie. conform to the null hypothesis). 

As you can see, the two-tailed probability is basically what you calculated using the binomial approach.

The one-tailed probability is the chance that the means are the same if we assume directionality (the mean of voltage on is less than voltage off), which is a step too far in my opinion.

At the bare minimum, we would have to see the P(T<=t) two-tail result to be less than 0.05 to call this result statistically significant (in the sense a journal would call it statistically significant).  As it stands we can't conclude anything about the last test other than the slopes of mag on and mag off are so close as to be indistinguishable by statistical means. 

So for Flight test #2D, no, the null hypothesis is not in jeopardy.  To reiterate though, NSF-1701 Flight Test #2B did show a statistically significant difference between mag on and mag off.  The spreadsheet is attached.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 05:42 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430601#msg1430601">Quote from: wallofwolfstreet on 09/28/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430580#msg1430580">Quote from: glennfish on 09/28/2015 05:04 PM</a>
The data used was the most recent provided from yesterday with the mag-on/off coding provided this a.m.  Sorry to confuse that.

2nd, you're right about alternative statistical tests.  I had to stick to my simplest apriori assumption which was dirt simple.  Are the slopes different, yes or no?  :)   When you wear a methodology hat, you have to stick to what you said, even if it means you have to kick yourself in the head ten times because the real data suggests something different.

Your observations and suggestions are correct.   There's a slug of other things we can throw at this too many perhaps :), t test among them.  I haven't had the time today for more than a rudimentary look.

re the null hypothesis, that would in this case be  "The slopes are not different between power on vs power off states".  The null hypothesis appears to be in jeopardy.

I just did the t-test to the excel sheet you added.  You can see it in Sheet1 right next to the data columns, starting in cell E3.  I highlighted in green the two most important stats to note, namely the one-tailed and two-tailed probabilities that the means of mag on and mag off are actually the same (ie. conform to the null hypothesis). 

As you can see, the two-tailed probability is basically what you calculated using the binomial approach.

The one-tailed probability is the chance that the means are the same if we assume directionality (the mean of voltage on is less than voltage off), which is a step too far in my opinion.

At the bare minimum, we would have to see the P(T<=t) two-tail result to be less than 0.05 to call this result statistically significant (in the sense a journal would call it statistically significant).  As it stands we can't conclude anything about the last test other than the slopes of mag on and mag off are so close as to be indistinguishable by statistical means. 

So for the second test, no, the null hypothesis is not in jeopardy.  To reiterate though, the first test did show a statistically significant difference between mag on and mag off.  The spreadsheet is attached.
Thanks Wolfy, when you say First test, is it First test of Flight Test 2D yesterday?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 05:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430604#msg1430604">Quote from: rfmwguy on 09/28/2015 05:42 PM</a>
Thanks Wolfy, when you say First test, is it First test of Flight Test 2D yesterday?

Sorry for the confusion, I'm not hip with the lingo :P.

What I call "first test" is actually your Flight Test #2B, the very first test you performed with your new equipment and posted on friday. 

None of the above is for Flight Test #2D. 

Have edited my comment.  The excel file rfmwguytest1-t-test is the t-test performed on the data for NSF-1701 Flight Test #2B.

edit:  I'm not actually sure what is what anymore.  Is the data posted by JoeSteinregen here: http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430409#msg1430409
for FlightTest #2D?  If so, then the first excel file is for Flight Test #2D, not #2C.

I have not looked at Flight Test #2C

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 05:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430609#msg1430609">Quote from: wallofwolfstreet on 09/28/2015 05:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430604#msg1430604">Quote from: rfmwguy on 09/28/2015 05:42 PM</a>
Thanks Wolfy, when you say First test, is it First test of Flight Test 2D yesterday?

Sorry for the confusion, I'm not hip with the lingo :P.

What I call "first test" is actually your Flight Test #2B, the very first test you performed with your new equipment and posted on friday. 

None of the above is for Flight Test #2D.   

Have edited my comment.  The excel file rfmwguytest1-t-test is the t-test performed on the data for NSF-1701 Flight Test #2B.
No problemo...I'm trying to sort out if the 2 run on FT 2D showed less than the first. I believe it did, meaning the cold start was a better test condition for the frustum design. I think it may be, since the dimensions suggested probably didn't take into effect heating up of the assembly or the mag itself. A little tidbit for pondering you might say  8)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 06:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430601#msg1430601">Quote from: wallofwolfstreet on 09/28/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430580#msg1430580">Quote from: glennfish on 09/28/2015 05:04 PM</a>
The data used was the most recent provided from yesterday with the mag-on/off coding provided this a.m.  Sorry to confuse that.

2nd, you're right about alternative statistical tests.  I had to stick to my simplest apriori assumption which was dirt simple.  Are the slopes different, yes or no?  :)   When you wear a methodology hat, you have to stick to what you said, even if it means you have to kick yourself in the head ten times because the real data suggests something different.

Your observations and suggestions are correct.   There's a slug of other things we can throw at this too many perhaps :), t test among them.  I haven't had the time today for more than a rudimentary look.

re the null hypothesis, that would in this case be  "The slopes are not different between power on vs power off states".  The null hypothesis appears to be in jeopardy.

I just did the t-test to the excel sheet you added.  You can see it in Sheet1 right next to the data columns, starting in cell E3.  I highlighted in green the two most important stats to note, namely the one-tailed and two-tailed probabilities that the means of mag on and mag off are actually the same (ie. conform to the null hypothesis). 

As you can see, the two-tailed probability is basically what you calculated using the binomial approach.

The one-tailed probability is the chance that the means are the same if we assume directionality (the mean of voltage on is less than voltage off), which is a step too far in my opinion.

At the bare minimum, we would have to see the P(T<=t) two-tail result to be less than 0.05 to call this result statistically significant (in the sense a journal would call it statistically significant).  As it stands we can't conclude anything about the last test other than the slopes of mag on and mag off are so close as to be indistinguishable by statistical means. 

So for the second test, no, the null hypothesis is not in jeopardy.  To reiterate though, NSF-1701 Flight Test #2B did show a statistically significant difference between mag on and mag off.  The spreadsheet is attached.

I'm not sure if taking the mean of a slope is meaningful.  It might be more appropriate to run a t-test not on the slopes, but on the on/off data elements themselves.    If you look at the raw data, the slopes are almost all negative, consistent with the thermal trending, but the rate fits a polynomial, so the meaning of the slope comparison changes depending where you are on that fit.  If the thermal drift were linear, then... I'm still not convinced, but I'm open.

I may try to do a t of ts on the 47 data groups, if I can figure out what that means.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 06:48 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430621#msg1430621">Quote from: glennfish on 09/28/2015 06:18 PM</a>
I'm not sure if taking the mean of a slope is meaningful.  It might be more appropriate to run a t-test not on the slopes, but on the on/off data elements themselves.    If you look at the raw data, the slopes are almost all negative, consistent with the thermal trending, but the rate fits a polynomial, so the meaning of the slope comparison changes depending where you are on that fit.  If the thermal drift were linear, then... I'm still not convinced, but I'm open.

I may try to do a t of ts on the 47 data groups, if I can figure out what that means.

This is my read on the situation and justification for the t-test:

The rate of change of deflection is proportional to the force on the beam.  Ergo the slope of a section (a section being defined as mag on or off) is equal to the average rate of change of deflection over that section and is thus proportional to the average force on the beam over that section.

We want to know: is there a difference in the average force on the beam when the mag is on vs when it is off?

So a single cycle of mag on then off is a single data point.  We have one measure of average force on the beam for mag on and one average force on the beam with mag off.  This cycling on then off is repeated many times.

We now have many measures of force on the beam for mag on and also mag off. 

Now we apply the t-test to determine if there is a statistical difference between our two groups, average force on the beam with mag on and average force on the beam with mag off.

What do you feel could be improved in the justification?  What the t-test lets us do is answer, in a statistically formal way: "is the average force during mag on different than average force during mag off?"

Mathematically, it's identical your binomial theorem route except variance is naturally included into the t-test, whereas the binomial route incorporates variance implicitly.  The reason for using the t-test is that not only is it easier, but it's the accepted practice for comparing two means.       

Quote
If you look at the raw data, the slopes are almost all negative, consistent with the thermal trending,but the rate fits a polynomial, so the meaning of the slope comparison changes depending where you are on that fit.

Personally, I wouldn't touch any of the data with any kind of curve fit.  When you use a curve fit, you're making implicit assumptions about the data that you can't justify within the data. 

Given any finite data set, you can find a polynomial that fits that data perfectly if you go high enough in your order.  So the data fitting a polynomial is meaningless unless you can back up why it should fit a polynomial.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 09/28/2015 07:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430537#msg1430537">Quote from: rfmwguy on 09/28/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430060#msg1430060">Quote from: glennfish on 09/27/2015 03:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: aero on 09/27/2015 02:55 PM</a>


Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

...

If I put on my methodology hat, there are so many issues in the experimental design that collectively it's amazing that there are any interesting results at all.   All statistics can do is give a probability that a difference exists.  It says nothing about why the difference exists.  In a proper experimental design, you state your hypothesis and select your measurement and analysis method before you turn on the power.  In this case, finding an interesting statistic after performing the experiment would have gotten me thrown out of gradschool.

Thanks...this last paragraph had a lot of stopping power with me. Since I do not have an advanced degree in science, it took me a while for this to sink in. You are 100% correct. Classical scientific research states you cannot move forward without a hypothesis first.

It does beg the question, does this rule somehow limit potential discovery? I recall having this conversation many years ago, me being on the side of "try and find out" my engineering pal being on the side of rigorous adherance to classical methodology. We never resolved our "dispute" but its good to have this refreshed in our minds.

Had I followed canon, I would never have started my build, for I have no hypothesis on why this thing might work, I only know there was enough to spark my interest in trying...perhaps the classic scientific versus why not try argument might live on forever. :o
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430537#msg1430537">Quote from: rfmwguy on 09/28/2015 04:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430060#msg1430060">Quote from: glennfish on 09/27/2015 03:51 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430044#msg1430044">Quote from: aero on 09/27/2015 02:55 PM</a>


Two questions:

1 - Is anyone recording these data analysis efforts for posterity in such a controlled way as to eliminate confusion about which data run they apply to? On the wiki?

2 - Now that you know the limitations of rfmwguy's test set-up, what kind of test run or runs would be needed in order to provide statistical significance?

I wonder if it is possible/desirable to modify the microwave controller to provide more on/off cycles per minute and if such higher cycle rate would provide more usable data or would it simply blur the data generated even more?

Great job rfmwguy. Your tests have illustrated to all concerned that the test stand set-up is probably more important than the cavity, at least it has many more fiddly-bits to deal with. The cavity does what it does, its the test stand that determines whether or not it did anything.

...

If I put on my methodology hat, there are so many issues in the experimental design that collectively it's amazing that there are any interesting results at all.   All statistics can do is give a probability that a difference exists.  It says nothing about why the difference exists.  In a proper experimental design, you state your hypothesis and select your measurement and analysis method before you turn on the power.  In this case, finding an interesting statistic after performing the experiment would have gotten me thrown out of gradschool.

Thanks...this last paragraph had a lot of stopping power with me. Since I do not have an advanced degree in science, it took me a while for this to sink in. You are 100% correct. Classical scientific research states you cannot move forward without a hypothesis first.

It does beg the question, does this rule somehow limit potential discovery? I recall having this conversation many years ago, me being on the side of "try and find out" my engineering pal being on the side of rigorous adherance to classical methodology. We never resolved our "dispute" but its good to have this refreshed in our minds.

Had I followed canon, I would never have started my build, for I have no hypothesis on why this thing might work, I only know there was enough to spark my interest in trying...perhaps the classic scientific versus why not try argument might live on forever. :o

Try a general hypothesis - inserting a radio signal at the resonant frequency into the cavity will produce both heating effects and movement.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 07:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430627#msg1430627">Quote from: wallofwolfstreet on 09/28/2015 06:48 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430621#msg1430621">Quote from: glennfish on 09/28/2015 06:18 PM</a>
I'm not sure if taking the mean of a slope is meaningful.  It might be more appropriate to run a t-test not on the slopes, but on the on/off data elements themselves.    If you look at the raw data, the slopes are almost all negative, consistent with the thermal trending, but the rate fits a polynomial, so the meaning of the slope comparison changes depending where you are on that fit.  If the thermal drift were linear, then... I'm still not convinced, but I'm open.

I may try to do a t of ts on the 47 data groups, if I can figure out what that means.

This is my read on the situation and justification for the t-test:

The rate of change of defection is proportional to the force on the beam.  Ergo the slope of a section (a section being defined as mag on or off) is equal to the average rate of change of deflection over that section and is thus proportional to the average force on the beam over that section.

We want to know: is there a difference in the average force on the beam when the mag is on vs when it is off?

So a single cycle of mag on then off is a single data point.  We have one measure of average force on the beam for mag on and one average force on the beam with mag off.  This cycling on then off is repeated many times.

We now have many measures of force on the beam for mag on and also mag off. 

Now we apply the t-test to determine if there is a statistical difference between our two groups, average force on the beam with mag on and average force on the beam with mag off.

What do you feel could be improved in the justification?  What the t-test lets us do is answer, in a statistically formal way: "is the average force during mag on different than average force during mag off?"

Mathematically, it's identical your binomial theorem route except variance is naturally included into the t-test, whereas the binomial route incorporates variance implicitly.  The reason for using the t-test is that not only is it easier, but it's the accepted practice for comparing two means.       

Quote
If you look at the raw data, the slopes are almost all negative, consistent with the thermal trending,but the rate fits a polynomial, so the meaning of the slope comparison changes depending where you are on that fit.

Personally, I wouldn't touch any of the data with any kind of curve fit.  When you use a curve fit, you're making implicit assumptions about the data that you can't justify within the data. 

Given any finite data set, you can find a polynomial that fits that data perfectly if you go high enough in your order.  So the data fitting a polynomial is meaningless unless you can back up why it should fit a polynomial.

this in your note got me thinking:

So a single cycle of mag on then off is a single data point.  We have one measure of average force on the beam for mag on and one average force on the beam with mag off.  This cycling on then off is repeated many times.

We now have many measures of force on the beam for mag on and also mag off. 


You're right, it is a single measurement of the force on the beam.  Now the question is, how do we properly use those multiple data points to create a single measurement.

rate of change aka slope was my preferred method, but the oscillatory character of the beam makes that difficult, at least in the time windows of Mag/on - Mag/off

Average just tells us where on the polynomial we are, sorta (I usually use polynomials to find residuals, not to fit data).

Now here's some things to look at among others to derive a "measurement" of that window.  Not sure how to postfacto justify them, but...

1.  Max - Min<br/>2.  variance<br/>3.  1 sd interval


Got any other measurement surrogates?  :)

BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SlightPace on 09/28/2015 07:52 PM
Regarding doing T-tests on the slope of every cycle (maybe someone has made this point aldready):

Doing a normal t-test, I think, assumes both ON/OFF slopes on the whole have the same linear slope coefficient as each individual cycle that you're measuring. I think it would be more appropriate to compare each ON cycle and the subsequent OFF cycle as a pair, and do a paired t-test. Although I have to admit I think this is starting to approach p-hacking... The data is clearly not good enough.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 08:10 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
this in your note got me thinking:

So a single cycle of mag on then off is a single data point.  We have one measure of average force on the beam for mag on and one average force on the beam with mag off.  This cycling on then off is repeated many times.

We now have many measures of force on the beam for mag on and also mag off. 


You're right, it is a single measurement of the force on the beam.  Now the question is, how do we properly use those multiple data points to create a single measurement.

rate of change aka slope was my preferred method, but the oscillatory character of the beam makes that difficult, at least in the time windows of Mag/on - Mag/off

Average just tells us where on the polynomial we are, sorta (I usually use polynomials to find residuals, not to fit data).

Now here's some things to look at among others to derive a "measurement" of that window.  Not sure how to postfacto justify them, but...

1.  Max - Min<br/>2.  variance<br/>3.  1 sd interval


Got any other measurement surrogates?  :)

Quote
rate of change aka slope was my preferred method, but the oscillatory character of the beam makes that difficult, at least in the time windows of Mag/on - Mag/off

Slope is the best method, and in my opinion the only one given the beam stiction.  It is an implicit average of the rate of change of deflection over a single mag on/off period because the slope of a line between two points is the average rate of change between those points (by the fundamental theorem of calculus).

Quote
Average just tells us where on the polynomial we are, sorta (I usually use polynomials to find residuals, not to fit data).

I don't know what this means.  Maybe you could explain/teach it to me?

Quote
Now here's some things to look at among others to derive a "measurement" of that window.  Not sure how to postfacto justify them, but...

ehhh, but why?  We have the average rate of deflection by looking at the slope; what do we hope to gain from looking at max - min for example?

Neither variance or sd are valid proxies for thrust though, so definitely don't do that. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 08:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.

Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 08:34 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430654#msg1430654">Quote from: wallofwolfstreet on 09/28/2015 08:10 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
this in your note got me thinking:

So a single cycle of mag on then off is a single data point.  We have one measure of average force on the beam for mag on and one average force on the beam with mag off.  This cycling on then off is repeated many times.

We now have many measures of force on the beam for mag on and also mag off. 


You're right, it is a single measurement of the force on the beam.  Now the question is, how do we properly use those multiple data points to create a single measurement.

rate of change aka slope was my preferred method, but the oscillatory character of the beam makes that difficult, at least in the time windows of Mag/on - Mag/off

Average just tells us where on the polynomial we are, sorta (I usually use polynomials to find residuals, not to fit data).

Now here's some things to look at among others to derive a "measurement" of that window.  Not sure how to postfacto justify them, but...

1.  Max - Min<br/>2.  variance<br/>3.  1 sd interval


Got any other measurement surrogates?  :)

Quote
rate of change aka slope was my preferred method, but the oscillatory character of the beam makes that difficult, at least in the time windows of Mag/on - Mag/off

Slope is the best method, and in my opinion the only one given the beam stiction.  It is an implicit average of the rate of change of deflection over a single mag on/off period because the slope of a line between two points is the average rate of change between those points (by the fundamental theorem of calculus).

Quote
Average just tells us where on the polynomial we are, sorta (I usually use polynomials to find residuals, not to fit data).

I don't know what this means.  Maybe you could explain it to me?

Quote
Now here's some things to look at among others to derive a "measurement" of that window.  Not sure how to postfacto justify them, but...

ehhh, but why?  We have the average rate of deflection by looking at the slope; what do we hope to gain from looking at max - min for example?

Neither variance or sd are valid proxies for thrust though, so definitely don't do that.
One thing to keep in mind Wolfy, is the magnetron is not an instant-on device. There is typically a 3 second delay from hum to max emissions. I would not characterize mag ON as a single data point, but a dataset that needs to be analysed for mag power characterization. There should be 10 datapoints or so in this subset.

Wish it were a square wave type deflection, but is not. I think this is why some of the data shows a delay that might be misinterpreted as out of synch with audio.

These individual ON characterizations I think will be very important for other experiments using mags.

<edit> There is lots of data on "warm-up" times in a microwave. Found a chart that sort of characterizes it and states:

"FIG.'7 is a plot of cavity tempera tureagainst time from switch on to the end of cooking at time 56. It must be noted that during the stand-by mode (between 52 and 54) the cavity temperature is fairly modest (about 150' C.) but that it rises rapidly on commencement of cooking at time 54. It will also be noted from FIG. 4 that the temperature detected by the therrnister 40 is substantially the same at the end of cooking at 56 as it is at the beginning of cooking at time 54, thermostatic control maintaining"

per Patent Number: 5,089,679
Date of Patent: Feb. 18, 1992

https://patentimages.storage.googleapis.com/pdfs/US5089679.pdf

<edit2> There is a body of data out there that measures time delay via temperature of cavities, current, etc, but have not had luck finding Field Strength, or the EM Field within a cavity. I think we might be the first to study this characteristic, which I consider a direct measurement of magnetron performance, rather than indirect. I know that movement or pause against thermal lift is an indirect measurement, but there seems to be enough variation on the ON state that someone in future experiments (hint-Shell) might want to have an EM Field Strength channel recording in addition to deflection. (Sorry Shell, I saw the bus coming and I nudged you towards it)  ::)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 09/28/2015 09:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430657#msg1430657">Quote from: wallofwolfstreet on 09/28/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.
Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/28/2015 10:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

Step functions generate a lot of transient noise within a brief period of the application of the step.  Trying dropping a mass onto a spring system or applying a constant voltage to an RLC circuit (it's not technically noise because it's not random, but in practice the transient is usually so complicated or hard to calculate that it's treated as noise).

Think about it like this, when the magnetron is off, their is some noise.  I see no mechanism that would decrease the amount of noise in the system when we turn on the magnetron.  The magnetron itself brings noise, so clearly there is more noise when the magnetron is on (noise with magnetron off + noise of magnetron on).  It seems obvious to me, but I guess not.     

I suppose we'll have the answer when glennfish reports his analysis. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 10:24 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430657#msg1430657">Quote from: wallofwolfstreet on 09/28/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.
Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)
I might address this a bit, the LDS system is an industrial, shielded box and cables located about 7 feet from the frustum. The DAQ is mounted inside the shielded computer box for additional isolation. The AC is on a separate breaker feed. I'm pretty comfortable saying noise that EMI has been planned for pretty well.

For example, the analog output from the LDS is a shielded coaxial line.

<edit> Attached users guide and engineering spec sheet of the Z4M-W40 LDS that I used. Its where I spent the most money on the whole experiment.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/28/2015 10:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

Step functions generate a lot of transient noise within a brief period of the application of the step.  Trying dropping a mass onto a spring system or applying a constant voltage to an RLC circuit (it's not technically noise because it's not random, but in practice the transient is usually so complicated or hard to calculate that it's treated as noise).

Think about it like this, with the magnetron is off, their is some noise.  I see no mechanism that would decrease the amount of noise in the system when we turn on the magnetron.  The magnetron itself brings noise, so clearly there is more noise when the magnetron is on (noise with magnetron off + noise of magnetron on).  It seems obvious to me, but I guess not.     

I suppose we'll have the answer when glennfish reports his analysis.

Patience please.  :)  My food chain in life includes a boss 12 hours off from my time zone.  Right now I'm engaged in doing something else.

I'll get to this ASAP.  The noise issue is interesting.  Can someone point to relevant nyquist calculators while I'm engaged on the other side of the planet?

RFMWGUY.  I do have to say, sometimes I feel like a voyeur.  You're living the sexy experiment.  I'm just measuring the... uh...  whatever  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/28/2015 11:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430700#msg1430700">Quote from: glennfish on 09/28/2015 10:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

Step functions generate a lot of transient noise within a brief period of the application of the step.  Trying dropping a mass onto a spring system or applying a constant voltage to an RLC circuit (it's not technically noise because it's not random, but in practice the transient is usually so complicated or hard to calculate that it's treated as noise).

Think about it like this, with the magnetron is off, their is some noise.  I see no mechanism that would decrease the amount of noise in the system when we turn on the magnetron.  The magnetron itself brings noise, so clearly there is more noise when the magnetron is on (noise with magnetron off + noise of magnetron on).  It seems obvious to me, but I guess not.     

I suppose we'll have the answer when glennfish reports his analysis.

Patience please.  :)  My food chain in life includes a boss 12 hours off from my time zone.  Right now I'm engaged in doing something else.

I'll get to this ASAP.  The noise issue is interesting.  Can someone point to relevant nyquist calculators while I'm engaged on the other side of the planet?

RFMWGUY.  I do have to say, sometimes I feel like a voyeur.  You're living the sexy experiment.  I'm just measuring the... uh...  whatever  :)
Your "uh...whatever"...might be the best news this community has had in a while considering the secretive nature of the "military industrial complex" Eisenhower mentioned a few decades ago  ;)

It has been a shame we've been forced to do our own investigations outside of traditional sources...but hey...ya gotta do what ya gotta do...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 12:03 AM
Someone mentioned this a few dozen pages ago and I would have loved to have had this with my setup:

Schlieren Optics

https://youtu.be/mLp_rSBzteI
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 12:13 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430701#msg1430701">Quote from: rfmwguy on 09/28/2015 11:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430700#msg1430700">Quote from: glennfish on 09/28/2015 10:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

Step functions generate a lot of transient noise within a brief period of the application of the step.  Trying dropping a mass onto a spring system or applying a constant voltage to an RLC circuit (it's not technically noise because it's not random, but in practice the transient is usually so complicated or hard to calculate that it's treated as noise).

Think about it like this, with the magnetron is off, their is some noise.  I see no mechanism that would decrease the amount of noise in the system when we turn on the magnetron.  The magnetron itself brings noise, so clearly there is more noise when the magnetron is on (noise with magnetron off + noise of magnetron on).  It seems obvious to me, but I guess not.     

I suppose we'll have the answer when glennfish reports his analysis.

Patience please.  :)  My food chain in life includes a boss 12 hours off from my time zone.  Right now I'm engaged in doing something else.

I'll get to this ASAP.  The noise issue is interesting.  Can someone point to relevant nyquist calculators while I'm engaged on the other side of the planet?

RFMWGUY.  I do have to say, sometimes I feel like a voyeur.  You're living the sexy experiment.  I'm just measuring the... uh...  whatever  :)
Your "uh...whatever"...might be the best news this community has had in a while considering the secretive nature of the "military industrial complex" Eisenhower mentioned a few decades ago  ;)

It has been a shame we've been forced to do our own investigations outside of traditional sources...but hey...ya gotta do what ya gotta do...

I'm not going to be able to do anything for the next 12-14 hours.

I would like, however, to ask everyone to send some kind of praise to JoeSteinregen, likes, orchids, chocolate...  His contribution has been pivotal to making any statistical statements pro or con.  Without his contribution this would be just grist for the grinder.

And RFMWGUY for having the guts to provide data on the physically impossible.

And WallOfWolfStreet who is the perfect barb on just about everything.  Never accept anything anyone says.  :)

Back to my day job.  :(

Back sometime tomorrow.  I hope.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 12:30 AM
Thanks Joe and Wolfy and of course glennfish for "stellar" work. I would also like to tip the hat to a former poster deltamass whom I considered a great sounding board; often with a sense of humor sometimes lacking in scientific discussions. My balance beam has the name of "Floobie Stick" in his honor.

Here at NSF I've discovered support whether it be pro or con, presented in a civil, useful way with references  to back up positions. This is far more valueable that simply saying "it can't work because I say so" from a DIYers perspective.

If it turns out that my humble experiment has positive results, there is no one here I would pull out the Schadenfreude card with...not my style anyway...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jmossman on 09/29/2015 01:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
...
If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?
...

Step functions generate a lot of transient noise within a brief period of the application of the step.  Trying dropping a mass onto a spring system or applying a constant voltage to an RLC circuit (it's not technically noise because it's not random, but in practice the transient is usually so complicated or hard to calculate that it's treated as noise).

Think about it like this, when the magnetron is off, their is some noise.  I see no mechanism that would decrease the amount of noise in the system when we turn on the magnetron.  The magnetron itself brings noise, so clearly there is more noise when the magnetron is on (noise with magnetron off + noise of magnetron on).  It seems obvious to me, but I guess not.     

I suppose we'll have the answer when glennfish reports his analysis.

I suspect we're all thinking along the same lines.  Normally a transient response exists for both the assertion and de-assertion of a step  (i.e. turn on vs turn off).  Trying to isolate differences in the transient response for "on" versus "off" is probably a worthwhile endeavor since we won't have any new data for a while.  If the "on" and "off" have equal noise/signal content (freq, magnitude, etc) and have no discernible differences, then I think we can safely call a null result.

My thought is we might was well mine the data we have looking for any and all patterns.  I'm all for prioritizing those deemed "least controversial", but no harm throwing any algorithm we can at the problem.  An example would be to employ something like a search algorithm on each edge of the magnetron hum on/off time to see if there's a way to recognize different effects due to variable delay in energy on/off and/or potential frequency differences.

False positives are a necessary evil when looking for an answer to a question without a detailed understanding of how something works.   Correlation does *NOT* equal causation (i.e. a strong correlation between magnetron on/off and movement might simply be due to increased water vapor thrust while "on").   This data is so noisy I'd be happy to see correlation of any kind as a first step....  understanding anything close to causation will likely take much longer and require lots of future experiments.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/29/2015 01:29 AM

Quote
Done some frequency sweeps between 22.0 GHz and 25.6 GHz and recorded the RX power, current and force in order to find some clues for the resonance frequency.

I did it first without antenna and then with an omnidirectional antenna and finally with the cavity (with tuning screw and with fixed endplates)

There is something happening around 24.6 GHz in the RX graph (600s sweep) which comes together with a force change (fixed endplate cavity) - but I need to check it in detail before I post some information based just on assumptions.


I wanted to release the software for viewing the data today, but it has still a bug in the display for recordings longer than 480 seconds, so I´ll fix this first before I release it.

Don´t worry, it won´t take long.

I wonder if the tuning screw might be acting as a kind of shock absorber in the cavity, transmitting the thrust into screw rotations.  Either that or its somehow interfering with a tunneling effect.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/29/2015 01:43 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430726#msg1430726">Quote from: jmossman on 09/29/2015 01:14 AM</a>
I suspect we're all thinking along the same lines.  Normally a transient response exists for both the assertion and de-assertion of a step  (i.e. turn on vs turn off).  Trying to isolate differences in the transient response for "on" versus "off" is probably a worthwhile endeavor since we won't have any new data for a while.  If the "on" and "off" have equal noise/signal content (freq, magnitude, etc) and have no discernible differences, then I think we can safely call a null result.

My thought is we might was well mine the data we have looking for any and all patterns.  I'm all for prioritizing those deemed "least controversial", but no harm throwing any algorithm we can at the problem.  An example would be to employ something like a search algorithm on each edge of the magnetron hum on/off time to see if there's a way to recognize different effects due to variable delay in energy on/off and/or potential frequency differences.

False positives are a necessary evil when looking for an answer to a question without a detailed understanding of how something works.   Correlation does *NOT* equal causation (i.e. a strong correlation between magnetron on/off and movement might simply be due to increased water vapor thrust while "on").   This data is so noisy I'd be happy to see correlation of any kind as a first step....  understanding anything close to causation will likely take much longer and require lots of future experiments.

Well my intuition was wrong.  Contrary to what I said, at least in the data of NSF flight test #2B, the magnetron off periods actually have greater standard deviation than magnetron on periods at the p=0.05 significance level. 

That one is on me, just goes to remind me that I should always let the data speak for itself.  I was completely backwards and in a surprising statistically strong way.  There is some mechanism that appears to cause magnetron on periods to be less variable than magnetron off periods for the 13 runs of flight test #2B.   

This was determined just as before by applying the t-test to the set of standard deviations for on and off periods.  Here is a little video (https://www.youtube.com/watch?v=BlS11D2VL_U) on how to call the t-test as an excel function and a bit of an explanation of what it does.

The probability that the standard deviations for on and off are actually the same is only around 3.5%.

I attach the same spreadsheet I attached earlier with the new stdev analysis.  I added some color coding that I hope is helpful.  There was a minor error in the last attached spreadsheet for the #2B data (misplaced sign) that has been corrected and increased the significance of the difference between the slopes to the 0.5% level. 

So to follow up:
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
I suppose we'll have the answer when glennfish reports his analysis.
I was wrong. :)

Goes to show: 
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430714#msg1430714">Quote from: glennfish on 09/29/2015 12:13 AM</a>
Never accept anything anyone says.  :)
 ;)

EDIT  See glennfish's excellent comment (http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430741#msg1430741) on why the standard deviation analysis isn't accurate.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 02:02 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430726#msg1430726">Quote from: jmossman on 09/29/2015 01:14 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
...
If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?
...

Step functions generate a lot of transient noise within a brief period of the application of the step.  Trying dropping a mass onto a spring system or applying a constant voltage to an RLC circuit (it's not technically noise because it's not random, but in practice the transient is usually so complicated or hard to calculate that it's treated as noise).

Think about it like this, when the magnetron is off, their is some noise.  I see no mechanism that would decrease the amount of noise in the system when we turn on the magnetron.  The magnetron itself brings noise, so clearly there is more noise when the magnetron is on (noise with magnetron off + noise of magnetron on).  It seems obvious to me, but I guess not.     

I suppose we'll have the answer when glennfish reports his analysis.

I suspect we're all thinking along the same lines.  Normally a transient response exists for both the assertion and de-assertion of a step  (i.e. turn on vs turn off).  Trying to isolate differences in the transient response for "on" versus "off" is probably a worthwhile endeavor since we won't have any new data for a while.  If the "on" and "off" have equal noise/signal content (freq, magnitude, etc) and have no discernible differences, then I think we can safely call a null result.

My thought is we might was well mine the data we have looking for any and all patterns.  I'm all for prioritizing those deemed "least controversial", but no harm throwing any algorithm we can at the problem.  An example would be to employ something like a search algorithm on each edge of the magnetron hum on/off time to see if there's a way to recognize different effects due to variable delay in energy on/off and/or potential frequency differences.

False positives are a necessary evil when looking for an answer to a question without a detailed understanding of how something works.   Correlation does *NOT* equal causation (i.e. a strong correlation between magnetron on/off and movement might simply be due to increased water vapor thrust while "on").   This data is so noisy I'd be happy to see correlation of any kind as a first step....  understanding anything close to causation will likely take much longer and require lots of future experiments.
Thought about water vapor expulsion...with the narrow end down, this should drive frustum upwards in ON state. Not sure I could quantify its lift value however.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 02:12 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430735#msg1430735">Quote from: wallofwolfstreet on 09/29/2015 01:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430726#msg1430726">Quote from: jmossman on 09/29/2015 01:14 AM</a>
I suspect we're all thinking along the same lines.  Normally a transient response exists for both the assertion and de-assertion of a step  (i.e. turn on vs turn off).  Trying to isolate differences in the transient response for "on" versus "off" is probably a worthwhile endeavor since we won't have any new data for a while.  If the "on" and "off" have equal noise/signal content (freq, magnitude, etc) and have no discernible differences, then I think we can safely call a null result.

My thought is we might was well mine the data we have looking for any and all patterns.  I'm all for prioritizing those deemed "least controversial", but no harm throwing any algorithm we can at the problem.  An example would be to employ something like a search algorithm on each edge of the magnetron hum on/off time to see if there's a way to recognize different effects due to variable delay in energy on/off and/or potential frequency differences.

False positives are a necessary evil when looking for an answer to a question without a detailed understanding of how something works.   Correlation does *NOT* equal causation (i.e. a strong correlation between magnetron on/off and movement might simply be due to increased water vapor thrust while "on").   This data is so noisy I'd be happy to see correlation of any kind as a first step....  understanding anything close to causation will likely take much longer and require lots of future experiments.

Well my intuition was wrong.  Contrary to what I said, at least in the data of NSF flight test #2B, the magnetron off periods actually have greater standard deviation than magnetron on periods at the p=0.05 significance level. 

That one is on me, just goes to remind me that I should always let the data speak for itself.  I was completely backwards and in a surprising statistically strong way.  There is some mechanism that appears to cause magnetron on periods to be less variable than magnetron off periods for the 13 runs of flight test #2B.   

This was determined just as before by applying the t-test to the set of standard deviations for on and off periods.  Here is a little video (https://www.youtube.com/watch?v=BlS11D2VL_U) on how to call the t-test as an excel function and a bit of an explanation of what it does.

The probability that the standard deviations for on and off are actually the same is only around 3.5%.

I attach the same spreadsheet I attached earlier with the new stdev analysis.  I added some color coding that I hope is helpful.  There was a minor error in the last attached spreadsheet for the #2B data (misplaced sign) that has been corrected and increased the significance of the difference between the slopes to the 0.5% level. 

So to follow up:
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
I suppose we'll have the answer when glennfish reports his analysis.
I was wrong. :)

Goes to show: 
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430714#msg1430714">Quote from: glennfish on 09/29/2015 12:13 AM</a>
Never accept anything anyone says.  :)
 ;)

Caution Will Robinson.

Did you account for the fact the the ON data count # is alway greater than the OFF data count # in this data set?

When I looked at the max-min data, it was obvious that the deltas strongly (p > .9) favored the ON, but... the ON TIMES were longer than the OFF times... so if I discounted the durations, they were random.

Not clear on what you did here, but just want to ensure that you took that into account.  :)

Can anyone in this forum conjure up the ghost of Thomas Bayes?  We're really pushing the envelope here.  :)

More detail please.  :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 02:28 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430741#msg1430741">Quote from: glennfish on 09/29/2015 02:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430735#msg1430735">Quote from: wallofwolfstreet on 09/29/2015 01:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430726#msg1430726">Quote from: jmossman on 09/29/2015 01:14 AM</a>
I suspect we're all thinking along the same lines.  Normally a transient response exists for both the assertion and de-assertion of a step  (i.e. turn on vs turn off).  Trying to isolate differences in the transient response for "on" versus "off" is probably a worthwhile endeavor since we won't have any new data for a while.  If the "on" and "off" have equal noise/signal content (freq, magnitude, etc) and have no discernible differences, then I think we can safely call a null result.

My thought is we might was well mine the data we have looking for any and all patterns.  I'm all for prioritizing those deemed "least controversial", but no harm throwing any algorithm we can at the problem.  An example would be to employ something like a search algorithm on each edge of the magnetron hum on/off time to see if there's a way to recognize different effects due to variable delay in energy on/off and/or potential frequency differences.

False positives are a necessary evil when looking for an answer to a question without a detailed understanding of how something works.   Correlation does *NOT* equal causation (i.e. a strong correlation between magnetron on/off and movement might simply be due to increased water vapor thrust while "on").   This data is so noisy I'd be happy to see correlation of any kind as a first step....  understanding anything close to causation will likely take much longer and require lots of future experiments.

Well my intuition was wrong.  Contrary to what I said, at least in the data of NSF flight test #2B, the magnetron off periods actually have greater standard deviation than magnetron on periods at the p=0.05 significance level. 

That one is on me, just goes to remind me that I should always let the data speak for itself.  I was completely backwards and in a surprising statistically strong way.  There is some mechanism that appears to cause magnetron on periods to be less variable than magnetron off periods for the 13 runs of flight test #2B.   

This was determined just as before by applying the t-test to the set of standard deviations for on and off periods.  Here is a little video (https://www.youtube.com/watch?v=BlS11D2VL_U) on how to call the t-test as an excel function and a bit of an explanation of what it does.

The probability that the standard deviations for on and off are actually the same is only around 3.5%.

I attach the same spreadsheet I attached earlier with the new stdev analysis.  I added some color coding that I hope is helpful.  There was a minor error in the last attached spreadsheet for the #2B data (misplaced sign) that has been corrected and increased the significance of the difference between the slopes to the 0.5% level. 

So to follow up:
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
I suppose we'll have the answer when glennfish reports his analysis.
I was wrong. :)

Goes to show: 
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430714#msg1430714">Quote from: glennfish on 09/29/2015 12:13 AM</a>
Never accept anything anyone says.  :)
 ;)

Caution Will Robinson.

Did you account for the fact the the ON data count # is alway greater than the OFF data count # in this data set?

When I looked at the max-min data, it was obvious that the deltas strongly (p > .9) favored the ON, but... the ON TIMES were longer than the OFF times... so if I discounted the durations, they were random.

Not clear on what you did here, but just want to ensure that you took that into account.  :)

Can anyone in this forum conjure up the ghost of Thomas Bayes?  We're really pushing the envelope here.  :)

More detail please.  :)
Fascinating (eyebrow raised).

Wolfy has a nice spreadsheet, followed the video link and learned something new.

Isn't a ttest capable of differing no.s in dataset comparisons?

If not, think the central portion of ON would be best considering the mag seems to need a bit of time to fire up.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 02:40 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430744#msg1430744">Quote from: rfmwguy on 09/29/2015 02:28 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430741#msg1430741">Quote from: glennfish on 09/29/2015 02:12 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430735#msg1430735">Quote from: wallofwolfstreet on 09/29/2015 01:43 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430726#msg1430726">Quote from: jmossman on 09/29/2015 01:14 AM</a>
I suspect we're all thinking along the same lines.  Normally a transient response exists for both the assertion and de-assertion of a step  (i.e. turn on vs turn off).  Trying to isolate differences in the transient response for "on" versus "off" is probably a worthwhile endeavor since we won't have any new data for a while.  If the "on" and "off" have equal noise/signal content (freq, magnitude, etc) and have no discernible differences, then I think we can safely call a null result.

My thought is we might was well mine the data we have looking for any and all patterns.  I'm all for prioritizing those deemed "least controversial", but no harm throwing any algorithm we can at the problem.  An example would be to employ something like a search algorithm on each edge of the magnetron hum on/off time to see if there's a way to recognize different effects due to variable delay in energy on/off and/or potential frequency differences.

False positives are a necessary evil when looking for an answer to a question without a detailed understanding of how something works.   Correlation does *NOT* equal causation (i.e. a strong correlation between magnetron on/off and movement might simply be due to increased water vapor thrust while "on").   This data is so noisy I'd be happy to see correlation of any kind as a first step....  understanding anything close to causation will likely take much longer and require lots of future experiments.

Well my intuition was wrong.  Contrary to what I said, at least in the data of NSF flight test #2B, the magnetron off periods actually have greater standard deviation than magnetron on periods at the p=0.05 significance level. 

That one is on me, just goes to remind me that I should always let the data speak for itself.  I was completely backwards and in a surprising statistically strong way.  There is some mechanism that appears to cause magnetron on periods to be less variable than magnetron off periods for the 13 runs of flight test #2B.   

This was determined just as before by applying the t-test to the set of standard deviations for on and off periods.  Here is a little video (https://www.youtube.com/watch?v=BlS11D2VL_U) on how to call the t-test as an excel function and a bit of an explanation of what it does.

The probability that the standard deviations for on and off are actually the same is only around 3.5%.

I attach the same spreadsheet I attached earlier with the new stdev analysis.  I added some color coding that I hope is helpful.  There was a minor error in the last attached spreadsheet for the #2B data (misplaced sign) that has been corrected and increased the significance of the difference between the slopes to the 0.5% level. 

So to follow up:
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430694#msg1430694">Quote from: wallofwolfstreet on 09/28/2015 10:23 PM</a>
I suppose we'll have the answer when glennfish reports his analysis.
I was wrong. :)

Goes to show: 
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430714#msg1430714">Quote from: glennfish on 09/29/2015 12:13 AM</a>
Never accept anything anyone says.  :)
 ;)

Caution Will Robinson.

Did you account for the fact the the ON data count # is alway greater than the OFF data count # in this data set?

When I looked at the max-min data, it was obvious that the deltas strongly (p > .9) favored the ON, but... the ON TIMES were longer than the OFF times... so if I discounted the durations, they were random.

Not clear on what you did here, but just want to ensure that you took that into account.  :)

Can anyone in this forum conjure up the ghost of Thomas Bayes?  We're really pushing the envelope here.  :)

More detail please.  :)
Fascinating (eyebrow raised).

Wolfy has a nice spreadsheet, followed the video link and learned something new.

Isn't a ttest capable of differing no.s in dataset comparisons?

If not, think the central portion of ON would be best considering the mag seems to need a bit of time to fire up.

already tried that, using 1, 2, 3, 4, 5 second delays on the slope test.  Didn't change squat on this data sent.  :(

Need some time to go back to the previous test and review.

If you havent shipped the kit & kaboodle to SeaShells, I have a half dozen "please do this" recommendations for a next test.  They all focus on bypassing the timer on the microwave oven.  That seems to be your most onerous villian. In all the data I see, the oscillation freaking has a harmonic which matches the microwave oven on/off time.  As long as that harmonic is there I will loose lots of my not much left hair.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 09/29/2015 02:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430741#msg1430741">Quote from: glennfish on 09/29/2015 02:12 AM</a>
Caution Will Robinson.

Did you account for the fact the the ON data count # is alway greater than the OFF data count # in this data set?

When I looked at the max-min data, it was obvious that the deltas strongly (p > .9) favored the ON, but... the ON TIMES were longer than the OFF times... so if I discounted the durations, they were random.

Not clear on what you did here, but just want to ensure that you took that into account.  :)

Can anyone in this forum conjure up the ghost of Thomas Bayes?  We're really pushing the envelope here.  :)

More detail please.  :)

Quote
Did you account for the fact the the ON data count # is alway greater than the OFF data count # in this data set?

Mhmmm that point is dead on. 

Your right, because there is a consistent drift over the course of the whole test, and the mag OFF periods are longer than the mag ON periods, so mag OFF periods will always appear to show greater variability because they span a greater range of deflections.  If anything, its a stretch to be talking about standard deviation with that in mind since I'm not just looking at random noise but noise overlayed onto a trend.  A trend that is quite significant over the range of time periods over which I am calculating standard deviation too. 

The better methodology would be too use a sampling procedure within the mag on/off periods, or even to examine the first derivative statistics after the drifting upwards trend has been normalized out.   

So the tl;dr is that my previous conclusion on the mag OFF having greater variability than the Mag ON is based on a garbage analysis and should be disregarded.           

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 02:52 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430749#msg1430749">Quote from: glennfish on 09/29/2015 02:40 AM</a>

already tried that, using 1, 2, 3, 4, 5 second delays on the slope test.  Didn't change squat on this data sent.  :(

Need some time to go back to the previous test and review.

If you havent shipped the kit & kaboodle to SeaShells, I have a half dozen "please do this" recommendations for a next test.  They all focus on bypassing the timer on the microwave oven.  That seems to be your most onerous villian. In all the data I see, the oscillation freaking has a harmonic which matches the microwave oven on/off time.  As long as that harmonic is there I will loose lots of my not much left hair.
No pressure, but I now have my olds sitting smack dab where the test stand was.  :o

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 03:04 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430752#msg1430752">Quote from: rfmwguy on 09/29/2015 02:52 AM</a>

No pressure, but I now have my olds sitting smack dab where the test stand was.  :o

how much do you want for the olds?

Would you swap for a 2.0 liter deisel VW?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 03:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430753#msg1430753">Quote from: glennfish on 09/29/2015 03:04 AM</a>

Would you swap for a 2.0 liter deisel VW?
Uhhh...angry wife...angry life...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 09/29/2015 07:10 AM
Alright, I always wanted to ask this. Do you think NASA Eagleworks were able to go above 100 micronewtons and keep it constant? and pass the testing to the Glenn Research Center?

I do not want to speculate. Just curious  :).

My guess is they might have...but of course no paper yet to confirm or dismiss, but after the testing by rfmwguy I am more confident. On the other hand the "thrust" is still quite small so far..
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/29/2015 11:57 AM
I don't think you'll find any insider or knowledgeable person willing to comment about that on this high profile public forum. Those who did in the past got slapped on the head by management, so unless there is an official NASA press release, all you'll hear are the crickets....
(200.gif)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/29/2015 12:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430782#msg1430782">Quote from: Chrochne on 09/29/2015 07:10 AM</a>
Alright, I always wanted to ask this. Do you think NASA Eagleworks were able to go above 100 micronewtons and keep it constant? and pass the testing to the Glenn Research Center?

I do not want to speculate. Just curious  :).

My guess is they might have...but of course no paper yet to confirm or dismiss, but after the testing by rfmwguy I am more confident. On the other hand the "thrust" is still quite small so far..
I was asked the other day if Micro-newtons were just a little cookie.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 12:19 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430440#msg1430440">Quote from: rfmwguy on 09/28/2015 01:20 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>
I would like to ask the members of the forum for some input/opinions.

Some of you know me from my posts on various RF and microwave issues.   I am just now starting a DIY emdrive test effort – I am finally getting my workshop back on line following a move –and I want to try to build on the outstanding work of SeeShell, rfmwguy, and others to hopefully make some small contribution of my own.

Anyway – to the request.

There are a multitude of test environment design factors of course and this is just a start but in order to begin limiting the possible test space I have narrowed down overall test configurations to the following:

1.   Rotary Table configuration – unit under test (UUT) thrusting either posigrade or retrograde to rotation
2.   Linear (slide) configuration – air or other low friction surface.   UUT thrusting along the access of the slide.
3.   Balance Beam (ala rfmwguy and seeshells)  UUT thrusting either up or down

In my thinking all have things going for them as well as potential problems, but I would like to ask for  your thoughts on each configurations.   In particular these are the things I have been considering:

•   Overall Pros and Cons
•   Challenges to getting usable data output
•   Potential systemic and situational error sources
•   Data which should/can be measured for either signal or noise/error determinations

ANYTHING else you can think of –

Thanks in advance.   If you would prefer to reply by private message rather than on the forum that is fine with me however please indicate any information which you do not want disseminated further.

Herman

PS – for those who don’t know me and  to provide some credibility background  - I have worked in both professionally and DIY settings on RF from LF to 40+ Ghz, high power RF and RF power supplies, vacuum chambers and systems, nuclear power plants  and various and sundry other technical fields including aerospace and defense for the past 39 years.  Well acquainted with safety procedures - wrote some for my last company. This will be my first big retirement project and I can’t wait to get started. 
Yay! Welcome to the DIY world! Fear not, as I took a lot of the naysayer hits when I started posting a few months ago, so in a sense I've absorbed a lot of the pressure for those who follow  8)

I've thought long and hard about many of your questions. Rotary tables need an air source that will stir up all ambient air around the DUT. Same for a linear table. While I think horizontal measuring is best for ambient air measuring, the background artifacts can be a challenge.

Regarding vertical measurements, lift is an enemy, much more so that I would have thought, even with a wire mesh frustum. Extracting data out of the natural lift is difficult as you can see by the fine work done by data analysists here. I still think this is the way to go as it limits other mechanical and electrical variables.

Datalogging: suggest you go with a fast computer that can handle screen recording with ease. Datalogging is usually serial and even an old PC like mine handled it easily; not so with screen record. Quad core processor is a must. DAQ can be anything, but try to go with a 12 bit as a minumum. Locate several feet from frustum and power supplies.

Laser Displacement Sensors - highly recommend this for vertical measurements. Try to select a 40mm +/- 10mm range rather than a 100mm+ sensor. The closer, the better resolution...up to 7 digits. Try Omron or equivalent.

Setup in an area with no vents and cover windows for drafts. You can see the deflections as I simply approached the setup.

Have nothing else on AC lines feeding your gear that could draw a load (pretty basic advice).

Other than that, make sure you HAVE FUN. Thats really the bottom line Graybeard. We are here to help and support your efforts.
Thanks for the welcome and the most appreciated comments!

Re the rotary tables needing air sources and stirring up air around DUT – yes this is definitely a concern with that approach.  However I am researching other rotary table approaches without using air bearings – in particular because I think that the rotary table approach may be one of the easier systems to put in a vacuum chamber – more on that in a bit.  But I am definitely in the study mode – no decisions yet.   And I appreciate any and all comments on this.

Re: data logging – absolutely –I have a spare quad i7 which I can go with and 14 bit or 16 bit DAQ is my desire depending on what is affordable.   I plan on using NI Labview for a lot of data acquisition design and control.  Mainly it seems, in a parallel to real estate, the key is measure, measure, measure.

I very much like the laser displacement sensors you used on NSF-1701 and I plan to use them where ever appropriate.   Also good comments on A/C  lines and minimizing air flow.  In fact I hope to feed everything through an isolation transformer and/or inverter system – even the measurement systems.   That may be a bit of a stretch but that’s how I set up my hamshack and it seems to work well.   Several Kw rated iso transformers are a bit dear – even on eBay – but they last forever.

My initial build will likely use a faraday cage similar to Shell’s  which will also double as a wind break for air movements.   But eventually I hope to go to a vacuum chamber approach.   I have a left over vacuum system which can get down to 10-4 torr or even 10-5 torr on a good day if all the connections are really well sealed.   This was from some work maybe a decade ago on a Farnsworth fusor – fun little project but have to be VERY careful about neutrons and shielding or you may glow in the dark.   Even more than the emdrive, anyone playing with one should be fully trained on radiation and reactor safety!

 Since the pumps are the expensive part, I got to noodling over building a DIY vacuum chamber to enclose a emdrive test fixture  – several interesting designs on the net  - and its painstaking work and moderately costly but not out of the realm of possibility.  This will NOT be soon – definitely well into 2016. 

Overall my approach is going to be to plan and design inward.   What I mean by that is – there is a great deal of discussion on frustum design and options – and there will be much more in the next few months I expect – so I am going to first concentrate on design and construction of a test facility which is reusable, reconfigurable and hopefully will provide data that can feed into our statistical and theoretical wizards here – you guys just amaze me.

As I mentioned before – I am developing a formal test plan analysis for the whole thing – using - IEEE 829 as a very loose guide – I have worked with it before and it has a lot of good formalism but is really both overkill in some areas and not detailed enough in others for this effort.   As soon as I have to some coherent state I will post here on the forum.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 09/29/2015 12:19 PM
my guess using the force is:  they got their s/n goal and reliable thrust. not necessarily steady state thrust. They were almost there last we heard before they were told to clam up so it is reasonable to assume they got there. But even then it is uncertain they sent it to Glen.

Even though none of the amateur/semi-pro replication got that magnitude of signal yet; the varied approaches both of test articles and of testing rigs probably were/are probably helpful in fertilizing EW's own set ups.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 12:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430814#msg1430814">Quote from: SeeShells on 09/29/2015 12:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430782#msg1430782">Quote from: Chrochne on 09/29/2015 07:10 AM</a>
Alright, I always wanted to ask this. Do you think NASA Eagleworks were able to go above 100 micronewtons and keep it constant? and pass the testing to the Glenn Research Center?

I do not want to speculate. Just curious  :).

My guess is they might have...but of course no paper yet to confirm or dismiss, but after the testing by rfmwguy I am more confident. On the other hand the "thrust" is still quite small so far..
I was asked the other day if Micro-newtons were just a little cookie.
I **fig**ured that would come up sooner or later.   

H.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 12:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430471#msg1430471">Quote from: SlightPace on 09/28/2015 02:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>
I would like to ask the members of the forum for some input/opinions.

Some of you know me from my posts on various RF and microwave issues.   I am just now starting a DIY emdrive test effort – I am finally getting my workshop back on line following a move –and I want to try to build on the outstanding work of SeeShell, rfmwguy, and others to hopefully make some small contribution of my own.

Anyway – to the request.

There are a multitude of test environment design factors of course and this is just a start but in order to begin limiting the possible test space I have narrowed down overall test configurations to the following:

1.   Rotary Table configuration – unit under test (UUT) thrusting either posigrade or retrograde to rotation
2.   Linear (slide) configuration – air or other low friction surface.   UUT thrusting along the access of the slide.
3.   Balance Beam (ala rfmwguy and seeshells)  UUT thrusting either up or down

In my thinking all have things going for them as well as potential problems, but I would like to ask for  your thoughts on each configurations.   In particular these are the things I have been considering:

•   Overall Pros and Cons
•   Challenges to getting usable data output
•   Potential systemic and situational error sources
•   Data which should/can be measured for either signal or noise/error determinations

ANYTHING else you can think of –

Thanks in advance.   If you would prefer to reply by private message rather than on the forum that is fine with me however please indicate any information which you do not want disseminated further.

Herman

PS – for those who don’t know me and  to provide some credibility background  - I have worked in both professionally and DIY settings on RF from LF to 40+ Ghz, high power RF and RF power supplies, vacuum chambers and systems, nuclear power plants  and various and sundry other technical fields including aerospace and defense for the past 39 years.  Well acquainted with safety procedures - wrote some for my last company. This will be my first big retirement project and I can’t wait to get started. 

A rotary rig will allow unlimited contious accelleration (well, depending on friction in your rig) and therefore most likely a higher signal to noise ratio. It would also be easy to do control experiments like rotating the frustum 180 deg. for reverse thrust, or 90 degrees (pointing towards or away from the rotational axis) for zero thrust.
On the other hand, it will arguably be the most complicated setup to build.

Whichever configuration you choose, be very careful when you design your experiment. What is your hypothesis? How can you falsify it? What control experiments do you need? The most accurate measurements in the world won't save you if you don't know what it is you're measuring.
As I have mentioned earlier, in my opinion, the most important control experiment to do is one where you are knowingly injecting EM at a non-resonating frequency. That should be your "negative control" experiment. Naturally, this means you must know the resonant freq. of your cavity and so on.

It is of course also important that you do at least 3 independent repetitions of each experiment, the more the better.

Good luck!
Thank you !

Outstanding thoughts.

First - yes the rotary table approach is likely the most complex.  But it does seem to have some real advantages in flexibility and, as you mention, signal to noise factors.  In particular the ability to change the axis of (potentially real) thrust is one of the major advantages I want to use.   I may even consider 'dueling frustums' i.e. one posigrade and one retrograde to rotation on opposite sides of the table.   

The specification of hypothesis and goals of each test is one of the reasons I will be formally documenting a test plan.  I have been following the hypothesis discussion hear closely and I will say more on that later but there MUST be control experiments and null drive configurations.   In particular I am very interested in what happens off design point with frequencies far from resonance.  Likewise with heating the frustum in a manner which will be null for thrust but can heat it up etc.   

I also completely agree with 3x or better tests.  Likewise when test configuration or conditions are changed only one is changed at a time.   This takes time but results in hopefully more useful data. 

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 12:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430657#msg1430657">Quote from: wallofwolfstreet on 09/28/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.
Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

on noise.

Noise is typically calculated on the basis of a known signal, and a measurement of how that signal degrades.  We don't really have that in this data.

A surrogate to noise is the standard deviation or variance.

Comparing two variances is generally verboten, but there are a some ways.

I chose, to answer your question, something called the Coefficient of Variation.  I'm not sure it's a good method with this data.  It's basically, the standard deviation / mean

It doesn't take the sample size into account, but it does sorta what you were asking about.

Spreadsheet attached ("macro's not included")

raw data in sheet raw2.php
summary in sheet Sheet1

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 01:18 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>

Anyway – to the request.

...
•   Data which should/can be measured for either signal or noise/error determinations



As one of the data geeks here, one thing that's become apparant is that the data should be as complete and sharable as possible.   The limited analysis I've done has depended on multiple other people massaging the data before I touch it.   I'd like to propose some sort of data interchange standard, but I don't know squat about what we should be measuring.  I don't know how fast you should sample, but as a rule of thumb, sample as fast as you can for as long as you can.

In general, include for each sample

1. time stamp (maximum possible accuracy...  microsecond resolution would be cool)
2. state of the device (on/off)
3. other states, i.e. forward, backward, as many states as you can collect
...
4.  measurement 1
5.  measurement 2   as many simultaneous measurements as you can grab
...  etc

CSV format is ideal, it works with almost everything
xls format is ok, most of us can work with that

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 01:41 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430831#msg1430831">Quote from: glennfish on 09/29/2015 01:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>

Anyway – to the request.

...
•   Data which should/can be measured for either signal or noise/error determinations



As one of the data geeks here, one thing that's become apparant is that the data should be as complete and sharable as possible.   The limited analysis I've done has depended on multiple other people massaging the data before I touch it.   I'd like to propose some sort of data interchange standard, but I don't know squat about what we should be measuring.  I don't know how fast you should sample, but as a rule of thumb, sample as fast as you can for as long as you can.

In general, include for each sample

1. time stamp (maximum possible accuracy...  microsecond resolution would be cool)
2. state of the device (on/off)
3. other states, i.e. forward, backward, as many states as you can collect
...
4.  measurement 1
5.  measurement 2   as many simultaneous measurements as you can grab
...  etc

CSV format is ideal, it works with almost everything
xls format is ok, most of us can work with that

Outstanding idea.   Likewise I would also suggest to naming data files or other data artifacts in a unique and unambiguous way and  record somewhere a detailed description of your test configuration with the same name or description.

 In my former life we tended to use something like "PROJ-TEST-TESTNUMBER-DATE/TIME"  Where PROJ was a unique project name, TEST was a unique name for the overall test configuration being used, TESTNUMBER was a sequential number of tests in the TEST configuration or better yet a unique number in the whole PROJ area, and DATE/TIME were just that - a unique date and time stamp of the start or stop of the test - whatever your datalogger will support.   It seems very pedantic and like a lot of extra work but 3 months later ( or 3 days sometimes) you will be able to unambiguously know which test generated each data set.   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 02:00 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430823#msg1430823">Quote from: glennfish on 09/29/2015 12:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430657#msg1430657">Quote from: wallofwolfstreet on 09/28/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.
Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

on noise.

Noise is typically calculated on the basis of a known signal, and a measurement of how that signal degrades.  We don't really have that in this data.

A surrogate to noise is the standard deviation or variance.

Comparing two variances is generally verboten, but there are a some ways.

I chose, to answer your question, something called the Coefficient of Variation.  I'm not sure it's a good method with this data.  It's basically, the standard deviation / mean

It doesn't take the sample size into account, but it does sorta what you were asking about.

Spreadsheet attached ("macro's not included")

raw data in sheet raw2.php
summary in sheet Sheet1
Wow, impressive spreadsheet, especially sheet 2 graphs (my visual brain speaking). Can you conclude your first glimpse into ft 2d shows a statistical variance between on/off beyond the probability threshold?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 02:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430837#msg1430837">Quote from: rfmwguy on 09/29/2015 02:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430823#msg1430823">Quote from: glennfish on 09/29/2015 12:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430657#msg1430657">Quote from: wallofwolfstreet on 09/28/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.
Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

on noise.

Noise is typically calculated on the basis of a known signal, and a measurement of how that signal degrades.  We don't really have that in this data.

A surrogate to noise is the standard deviation or variance.

Comparing two variances is generally verboten, but there are a some ways.

I chose, to answer your question, something called the Coefficient of Variation.  I'm not sure it's a good method with this data.  It's basically, the standard deviation / mean

It doesn't take the sample size into account, but it does sorta what you were asking about.

Spreadsheet attached ("macro's not included")

raw data in sheet raw2.php
summary in sheet Sheet1
Wow, impressive spreadsheet, especially sheet 2 graphs (my visual brain speaking). Can you conclude your first glimpse into ft 2d shows a statistical variance between on/off beyond the probability threshold?

The sheet reflects my scatterbrained approach to figuring out what should be looked at. 

There is no question that the on CV is greater than the off CV.  p > .99

BUT, I'm not sure if that's real or an artifact of the different data counts during a downward trend. 

Gotta think some more.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/29/2015 02:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430821#msg1430821">Quote from: graybeardsyseng on 09/29/2015 12:39 PM</a>

The specification of hypothesis and goals of each test is one of the reasons I will be formally documenting a test plan.  I have been following the hypothesis discussion hear closely and I will say more on that later but there MUST be control experiments and null drive configurations.   In particular I am very interested in what happens off design point with frequencies far from resonance.  Likewise with heating the frustum in a manner which will be null for thrust but can heat it up etc.   

I also completely agree with 3x or better tests.  Likewise when test configuration or conditions are changed only one is changed at a time.   This takes time but results in hopefully more useful data. 

Herman

I'm not sure a null test is possible in a frustum unless it's unpowered.  Anything else will generate heat, and you're now testing theories about the importance of frequency and Q.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/29/2015 02:26 PM
A while back, somebody noted an experiment that showed thrust by bouncing a laser back and forth.  Was this a photonic laser rocket (cool tech, well understood) or did you mean it showed thrust by bouncing a laser off several mirrors and measuring the thrust at the last mirror.  If so, can you post a link to the paper or report?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 02:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430844#msg1430844">Quote from: glennfish on 09/29/2015 02:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430837#msg1430837">Quote from: rfmwguy on 09/29/2015 02:00 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430823#msg1430823">Quote from: glennfish on 09/29/2015 12:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430683#msg1430683">Quote from: jmossman on 09/28/2015 09:32 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430657#msg1430657">Quote from: wallofwolfstreet on 09/28/2015 08:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430644#msg1430644">Quote from: glennfish on 09/28/2015 07:35 PM</a>
BTW I just tried max-min and sd,   the results were surpising.  Now why is that....   Gotta think a bit before sharing.
Because both max-min and sd are measurements of the variability of a time series, and the periods when the magnetron is on are naturally going to be more noisy than when the magnetron is off, ceterus paribus?

Why do we know that "the periods when the magnetron is on are naturally going to be more noisy"?  ???

In my mind's eye, we might have a step function being injected.  I don't see a rigorous apriore justification for why the "noise" is greater for the "on" versus "off" period.  We can start to make assumptions about 60Hz "steps" (or impulses) during the "on" period, but the resolution of the data is so low I don't see how such 60Hz "steps" could possibly be resolved.  Instead, I would have thought the mechanical system acting as a crude low pass filter would be a more likely scenario...  which leads back to the original question:  why should we expect to see more noise during "on" than "off"?

If we can show statistically that the data *IS* noisier while the magnetron is on, then I think that would be very valuable piece of information.  For example, if there is more "noise" while the magnetron is on, a follow-on question would be:  what does the "noise" look like?

So in summary, I'm quite interested in hearing what @Glennfish noticed while performing simple min/max and sd calculations.   ;)

on noise.

Noise is typically calculated on the basis of a known signal, and a measurement of how that signal degrades.  We don't really have that in this data.

A surrogate to noise is the standard deviation or variance.

Comparing two variances is generally verboten, but there are a some ways.

I chose, to answer your question, something called the Coefficient of Variation.  I'm not sure it's a good method with this data.  It's basically, the standard deviation / mean

It doesn't take the sample size into account, but it does sorta what you were asking about.

Spreadsheet attached ("macro's not included")

raw data in sheet raw2.php
summary in sheet Sheet1
Wow, impressive spreadsheet, especially sheet 2 graphs (my visual brain speaking). Can you conclude your first glimpse into ft 2d shows a statistical variance between on/off beyond the probability threshold?

The sheet reflects my scatterbrained approach to figuring out what should be looked at. 

There is no question that the on CV is greater than the off CV.  p > .99

BUT, I'm not sure if that's real or an artifact of the different data counts during a downward trend. 

Gotta think some more.
Your thinking will pay off for future experimenters. The data overlay approach with mag ON/OFF is important. While OFF (lift) is moderately well behaved, ON has additional variables in the time domain such as mag frequency and power levels across a 40 MHz spectrum. Wish it were a square wave, instant ON with no level, thermal or frequency variations, but that is not the nature of the beast. RF power level in a mag is a delayed buildup akin to a cap charge best I can determine by reading and personal observation. Its frequencies  slip across a natural frustum resonance; which itself changes with temperature.

This is where a perfect experiment might be with a clean, single frequency injection and a frustum capable of "synching" or tuning resonance to track that signal. This would get us closer to a "square wave" ON condition I believe, maximizing the effect in the time domain.

This is probably old news to SPR, EW and yang, but worth the DIY community thinking about...unless you perfect the ability to separate the wheat from the chaff  ::)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 02:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430845#msg1430845">Quote from: SteveD on 09/29/2015 02:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430821#msg1430821">Quote from: graybeardsyseng on 09/29/2015 12:39 PM</a>

The specification of hypothesis and goals of each test is one of the reasons I will be formally documenting a test plan.  I have been following the hypothesis discussion hear closely and I will say more on that later but there MUST be control experiments and null drive configurations.   In particular I am very interested in what happens off design point with frequencies far from resonance.  Likewise with heating the frustum in a manner which will be null for thrust but can heat it up etc.   

I also completely agree with 3x or better tests.  Likewise when test configuration or conditions are changed only one is changed at a time.   This takes time but results in hopefully more useful data. 

Herman

I'm not sure a null test is possible in a frustum unless it's unpowered.  Anything else will generate heat, and you're now testing theories about the importance of frequency and Q.

Likely you are correct.   But I think I didn't say what I was trying to say very well.   Back a ways on the forum - maybe even back on Thread 3 - there as discussions of running a test in which there was heating but no RF energy actually coupled into the cavity.  Discussion - IIRC - even included ideas for ohmic DC heating of the cavity and waveguides.   The idea at that time was to attempt to duplicate the thermal input that was occurring during the "live" test but without the possibility for the potentially existing em generated thrust and thereby attempt to quantify the "lift" or "thrust" due to the thermal heating .   At the time I was wondering about the potential fidelity of these sorts of tests, but I did think that if it could be done in am manner to duplicated the "flight" configuration but without coupling RF it might provide some useful control data.   It might also be a bit of pursuing the wild goose.

H

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 03:32 PM
Scientific proof that I have my old car and the garage back. Note the Floobie Stick safely hanging on the wall  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 04:42 PM
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/29/2015 04:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430866#msg1430866">Quote from: graybeardsyseng on 09/29/2015 02:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430845#msg1430845">Quote from: SteveD on 09/29/2015 02:16 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430821#msg1430821">Quote from: graybeardsyseng on 09/29/2015 12:39 PM</a>

The specification of hypothesis and goals of each test is one of the reasons I will be formally documenting a test plan.  I have been following the hypothesis discussion hear closely and I will say more on that later but there MUST be control experiments and null drive configurations.   In particular I am very interested in what happens off design point with frequencies far from resonance.  Likewise with heating the frustum in a manner which will be null for thrust but can heat it up etc.   

I also completely agree with 3x or better tests.  Likewise when test configuration or conditions are changed only one is changed at a time.   This takes time but results in hopefully more useful data. 

Herman

I'm not sure a null test is possible in a frustum unless it's unpowered.  Anything else will generate heat, and you're now testing theories about the importance of frequency and Q.

Likely you are correct.   But I think I didn't say what I was trying to say very well.   Back a ways on the forum - maybe even back on Thread 3 - there as discussions of running a test in which there was heating but no RF energy actually coupled into the cavity.  Discussion - IIRC - even included ideas for ohmic DC heating of the cavity and waveguides.   The idea at that time was to attempt to duplicate the thermal input that was occurring during the "live" test but without the possibility for the potentially existing em generated thrust and thereby attempt to quantify the "lift" or "thrust" due to the thermal heating .   At the time I was wondering about the potential fidelity of these sorts of tests, but I did think that if it could be done in am manner to duplicated the "flight" configuration but without coupling RF it might provide some useful control data.   It might also be a bit of pursuing the wild goose.

H

Well here's the thing.  The only successful null tests I know of right now involve either a symmetrical resonance cavity or measurements with everything off.  If you put a heating element in, it will produce photons of infrared radiation.  I'm not at all sure that any form of electromagnetic radiation isn't going to produce a thrust effect at some level.

This effect appears so robust that the answer, when its found, has to be dirt simple.  We're talking teach it in high school level simple, not "the logic gates in my silicon wafer are having difficulty because I've made the circuits so small that quantum tunneling is an issue."

So we have thrust from energy.  What is the simplest explanation of thrust from energy: a photon rocket.  We are getting more thrust than a photon rocket.  How to you amplify the energy of a photon rocket: with a mirror.  Simplest explanation is that reflection is somehow amplifying the photon rocket effect.  Noether say's a closed system can't move on its own (though I get the feeling what she was really trying to say is that math can be used to deduce properties any physical system must have, so if you're looking at something new you have some idea what to look for).  Since it can't be a closed system and go, it must not be a closed system.  So either an outside force is working on it or something is escaping.

Given all of that then, if the outside force is not invoked, you can have a null test.  If the answer is something is escaping, anything that emits photons is likely to produce a result.  You can only get to null by changing the manner in which that thing escapes.

Which is why I'm looking for those laser studies, to see if something similar has been noted in tests that are bouncing photons around.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/29/2015 05:12 PM
Regarding the null test. Aren't we pretty sure that a cylindrical resonator will not thrust? It will heat and do all the other things, but if something is escaping, that something should escape symmetrically, no thrust. If nothing is escaping then still no thrust due to symmetry.

Of course getting the heating rates right may be a little tricky when it comes to comparing to a real EM Drive configuration.

I do think the idea posted much earlier by (I forget who posted it), the idea of two identical frustums, one at each end of a balance beam, would go a long way toward eliminating thermal lift from the data. The idea was to mount both frustums upward, run to steady state then turn one off. Or mount one up, one down and run synchronously, doubling the thrust effect while significantly reducing the lift effect. This one would allow data collection from initial power on of the cold system and still reduce the effect of thermal lift.

Only problem is that it takes two frustums, but rfmwguy can tell us how much difficulty and cost would be involved in building the second identical frustum. And he could likely scope out the required modifications to the test rig as well.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 05:23 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430910#msg1430910">Quote from: aero on 09/29/2015 05:12 PM</a>
Regarding the null test. Aren't we pretty sure that a cylindrical resonator will not thrust? It will heat and do all the other things, but if something is escaping, that something should escape symmetrically, no thrust. If nothing is escaping then still no thrust due to symmetry.

Of course getting the heating rates right may be a little tricky when it comes to comparing to a real EM Drive configuration.

I do think the idea posted much earlier by (I forget who posted it), the idea of two identical frustums, one at each end of a balance beam, would go a long way toward eliminating thermal lift from the data. The idea was to mount both frustums upward, run to steady state then turn one off. Or mount one up, one down and run synchronously, doubling the thrust effect while significantly reducing the lift effect. This one would allow data collection from initial power on of the cold system and still reduce the effect of thermal lift.

Only problem is that it takes two frustums, but rfmwguy can tell us how much difficulty and cost would be involved in building the second identical frustum. And he could likely scope out the required modifications to the test rig as well.

And the difficulty with the word "identical"  meaning identical fabrication, feeding, power coupled etc.     Not easy.  Do-able, but not easy.
H

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 05:25 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 05:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430910#msg1430910">Quote from: aero on 09/29/2015 05:12 PM</a>
Regarding the null test. Aren't we pretty sure that a cylindrical resonator will not thrust? It will heat and do all the other things, but if something is escaping, that something should escape symmetrically, no thrust. If nothing is escaping then still no thrust due to symmetry.

Of course getting the heating rates right may be a little tricky when it comes to comparing to a real EM Drive configuration.

I do think the idea posted much earlier by (I forget who posted it), the idea of two identical frustums, one at each end of a balance beam, would go a long way toward eliminating thermal lift from the data. The idea was to mount both frustums upward, run to steady state then turn one off. Or mount one up, one down and run synchronously, doubling the thrust effect while significantly reducing the lift effect. This one would allow data collection from initial power on of the cold system and still reduce the effect of thermal lift.

Only problem is that it takes two frustums, but rfmwguy can tell us how much difficulty and cost would be involved in building the second identical frustum. And he could likely scope out the required modifications to the test rig as well.
It would be quite the challenge to build 2 identical units, mechanically and electrically. Even if you obtained a matched pair of mags, small mechanic differences in the frustum could negate a match. Then there's the thermal lift variables at two different places...opposite ends of frustum.

One thing I should have done is remove the frustum from balance beam and hang dead weight in its place. Fire it up and check for system noise afterwards. Problem with this is where to put voltage wires...on the beam or off. Either way, not an easy way to quantify system noise.

Regarding thermal lift, only way I know how to negate this is in a vacuum. I think glennfish's plan of overlaying on/off data is the best answer I've seen so far for us airbreathers.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: watermod on 09/29/2015 05:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430833#msg1430833">Quote from: graybeardsyseng on 09/29/2015 01:41 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430831#msg1430831">Quote from: glennfish on 09/29/2015 01:18 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430234#msg1430234">Quote from: graybeardsyseng on 09/28/2015 02:44 AM</a>

Anyway – to the request.

...
•   Data which should/can be measured for either signal or noise/error determinations



As one of the data geeks here, one thing that's become apparant is that the data should be as complete and sharable as possible.   The limited analysis I've done has depended on multiple other people massaging the data before I touch it.   I'd like to propose some sort of data interchange standard, but I don't know squat about what we should be measuring.  I don't know how fast you should sample, but as a rule of thumb, sample as fast as you can for as long as you can.

In general, include for each sample

1. time stamp (maximum possible accuracy...  microsecond resolution would be cool)
2. state of the device (on/off)
3. other states, i.e. forward, backward, as many states as you can collect
...
4.  measurement 1
5.  measurement 2   as many simultaneous measurements as you can grab
...  etc

CSV format is ideal, it works with almost everything
xls format is ok, most of us can work with that

Outstanding idea.   Likewise I would also suggest to naming data files or other data artifacts in a unique and unambiguous way and  record somewhere a detailed description of your test configuration with the same name or description.

 In my former life we tended to use something like "PROJ-TEST-TESTNUMBER-DATE/TIME"  Where PROJ was a unique project name, TEST was a unique name for the overall test configuration being used, TESTNUMBER was a sequential number of tests in the TEST configuration or better yet a unique number in the whole PROJ area, and DATE/TIME were just that - a unique date and time stamp of the start or stop of the test - whatever your datalogger will support.   It seems very pedantic and like a lot of extra work but 3 months later ( or 3 days sometimes) you will be able to unambiguously know which test generated each data set.
Somewhere in my archives I have a web based testing software that does all that and more.   It was developed to datamine test and inject for huge cellular test labs.   The company division it was developed for no longer exists and the company has been diced and sliced many times.   There were 2 versions of it one in C++ and one in Java.  I don't think I can release it but could pull out the key information.   It was data store independent with all data available in CSV ascii.  All tests recorded configuration, state, statuses, tester(s), labs, devices and gigabytes of data, GPS derived  timestamps on all data and the like.   You could configure, control, run and access data from any lab on the web via your browser.  Informics, Oracle, MySql, Microsoft SQL and Postgres were supported database formats.  It might be interesting to see something like that for distributed research like this.       

Another option and one more would be familiar with is the testing software framework used by the huge national and international collider labs.
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 06:03 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430920#msg1430920">Quote from: glennfish on 09/29/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?
Its a good thing, as it confirms the hypothesis that ON does not provide instantaneous results, as in a square-wave voltage change. Mag heating, frequency and resonance shift all combine (my belief) for variances shown in the points you made above. On the other hand, mag OFF is rather calm and predictable, with mother nature taking over and gently thermal lifting the DUT.

Not sure if the 50% point is the best point to sub-divide, but the ON state variances versus the OFF state variances is a decent way to look at the data subset.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 06:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430931#msg1430931">Quote from: rfmwguy on 09/29/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430920#msg1430920">Quote from: glennfish on 09/29/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?
Its a good thing, as it confirms the hypothesis that ON does not provide instantaneous results, as in a square-wave voltage change. Mag heating, frequency and resonance shift all combine (my belief) for variances shown in the points you made above. On the other hand, mag OFF is rather calm and predictable, with mother nature taking over and gently thermal lifting the DUT.

Not sure if the 50% point is the best point to sub-divide, but the ON state variances versus the OFF state variances is a decent way to look at the data subset.

OK spreadsheet with analysis (no VBA)

Sheet:  raw.php
    raw data and processing

Sheet:  Sheet1
    summary & results

               m1>m2   m1<=m2        
Group ON       29                18        
Group OFF       14                33        

Fisher's exact test, two tailed p = .0035
Fisher's exact test, one tailed p = .0018

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 07:05 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430943#msg1430943">Quote from: rfmwguy on 09/29/2015 06:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430941#msg1430941">Quote from: glennfish on 09/29/2015 06:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430931#msg1430931">Quote from: rfmwguy on 09/29/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430920#msg1430920">Quote from: glennfish on 09/29/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?
Its a good thing, as it confirms the hypothesis that ON does not provide instantaneous results, as in a square-wave voltage change. Mag heating, frequency and resonance shift all combine (my belief) for variances shown in the points you made above. On the other hand, mag OFF is rather calm and predictable, with mother nature taking over and gently thermal lifting the DUT.

Not sure if the 50% point is the best point to sub-divide, but the ON state variances versus the OFF state variances is a decent way to look at the data subset.

OK spreadsheet with analysis (no VBA)

Sheet:  raw.php
    raw data and processing

Sheet:  Sheet1
    summary & results

               m1>m2   m1<=m2        
Group ON       29                18        
Group OFF       14                33        

Fisher's exact test, two tailed p = .0035
Fisher's exact test, one tailed p = .0018
Nice glenn, for us stat-light posters out here, what does the data tell you?

stat-light... sounds like a beer :)

OK, there is a very significant difference between the slope behavior for on vs. off, given by the values of p.  Close to 1 is bad.  Close to 0 is good.

What this indicates is:

If ON, the slope is likely to become more negative during the cycle.
If OFF, the slope is likely to not change or become less negative during the cycle.

examples
              define m1 as the slope during the 1st half of the cycle and m2 as the slope during the last half of the cycle.
              if m1 = -2 and m2 = -3   then m1>m2 = TRUE
              if m1 = -2 and m2 = -1   then m1>m2 = FALSE

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: watermod on 09/29/2015 07:33 PM
When doing tests with multiple sensors and possibly multiple platforms timing quickly becomes an engineering challenge.   Enclosed is a timing paper I had commissioned, around March 2000, so that our test tools could adequately deal with measurement.   It was quite useful to us.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 07:59 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430947#msg1430947">Quote from: glennfish on 09/29/2015 07:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430943#msg1430943">Quote from: rfmwguy on 09/29/2015 06:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430941#msg1430941">Quote from: glennfish on 09/29/2015 06:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430931#msg1430931">Quote from: rfmwguy on 09/29/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430920#msg1430920">Quote from: glennfish on 09/29/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?
Its a good thing, as it confirms the hypothesis that ON does not provide instantaneous results, as in a square-wave voltage change. Mag heating, frequency and resonance shift all combine (my belief) for variances shown in the points you made above. On the other hand, mag OFF is rather calm and predictable, with mother nature taking over and gently thermal lifting the DUT.

Not sure if the 50% point is the best point to sub-divide, but the ON state variances versus the OFF state variances is a decent way to look at the data subset.

OK spreadsheet with analysis (no VBA)

Sheet:  raw.php
    raw data and processing

Sheet:  Sheet1
    summary & results

               m1>m2  &nnbsp;m1<=m2        
Group ON       29                18        
Group OFF       14                33        

Fisher's exact test, two tailed p = .0035
Fisher's exact test, one tailed p = .0018
Nice glenn, for us stat-light posters out here, what does the data tell you?

stat-light... sounds like a beer :)

OK, there is a very significant difference between the slope behavior for on vs. off, given by the values of p.  Close to 1 is bad.  Close to 0 is good.

What this indicates is:

If ON, the slope is likely to become more negative during the cycle.
If OFF, the slope is likely to not change or become less negative during the cycle.

examples
              define m1 as the slope during the 1st half of the cycle and m2 as the slope during the last half of the cycle.
              if m1 = -2 and m2 = -3   then m1>m2 = TRUE
              if m1 = -2 and m2 = -1   then m1>m2 = FALSE
Ok, more confirmation of ON cycle changes. Looks like all roads leading to the conclusion that something is definitely happening, i.e. not a null test...positive not null. Fair statement?

I've been OCD like on not calling this effect thrust, and guess I will continue to do so. Without a true understanding of why this happens, it might as well be an attractive or repulsive force. Not 100% comfortable with thrust, so my shorthand is emdrive effect.

Guess a last piece of the puzzle is the open channel data points for relative system noise comparisons betwee on/off states. A quick glance, saw nothing significant in the numbers indicating an EMI induced spike or noise. Let me know if you concur.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/29/2015 08:49 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430963#msg1430963">Quote from: rfmwguy on 09/29/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430947#msg1430947">Quote from: glennfish on 09/29/2015 07:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430943#msg1430943">Quote from: rfmwguy on 09/29/2015 06:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430941#msg1430941">Quote from: glennfish on 09/29/2015 06:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430931#msg1430931">Quote from: rfmwguy on 09/29/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430920#msg1430920">Quote from: glennfish on 09/29/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?
Its a good thing, as it confirms the hypothesis that ON does not provide instantaneous results, as in a square-wave voltage change. Mag heating, frequency and resonance shift all combine (my belief) for variances shown in the points you made above. On the other hand, mag OFF is rather calm and predictable, with mother nature taking over and gently thermal lifting the DUT.

Not sure if the 50% point is the best point to sub-divide, but the ON state variances versus the OFF state variances is a decent way to look at the data subset.

OK spreadsheet with analysis (no VBA)

Sheet:  raw.php
    raw data and processing

Sheet:  Sheet1
    summary & results

               m1>m2   m1<=m2        
Group ON       29                18        
Group OFF       14                33        

Fisher's exact test, two tailed p = .0035
Fisher's exact test, one tailed p = .0018
Nice glenn, for us stat-light posters out here, what does the data tell you?

stat-light... sounds like a beer :)

OK, there is a very significant difference between the slope behavior for on vs. off, given by the values of p.  Close to 1 is bad.  Close to 0 is good.

What this indicates is:

If ON, the slope is likely to become more negative during the cycle.
If OFF, the slope is likely to not change or become less negative during the cycle.

examples
              define m1 as the slope during the 1st half of the cycle and m2 as the slope during the last half of the cycle.
              if m1 = -2 and m2 = -3   then m1>m2 = TRUE
              if m1 = -2 and m2 = -1   then m1>m2 = FALSE
Ok, more confirmation of ON cycle changes. Looks like all roads leading to the conclusion that something is definitely happening, i.e. not a null test...positive not null. Fair statement?

I've been OCD like on not calling this effect thrust, and guess I will continue to do so. Without a true understanding of why this happens, it might as well be an attractive or repulsive force. Not 100% comfortable with thrust, so my shorthand is emdrive effect.

Guess a last piece of the puzzle is the open channel data points for relative system noise comparisons betwee on/off states. A quick glance, saw nothing significant in the numbers indicating an EMI induced spike or noise. Let me know if you concur.


Physics isn't my strong suit.  Simply put, when power is on, things are different than when power is off.  The data supports that. 

You have shared your data, and others here have shared their data and analysis.  It's fair game for anyone with an internet connection to review, critique, replicate, or ignore.

re the noise numbers in those other channels, I haven't looked extensively but a quick look shows they seem rather random.  I did a couple of quick correlation analyses and the rs were in the .00x range.  There are only a few discrete values and they look like the lowest possible DAC's deviation from a ground state.  They are definitely not correlated with your actual data.  I'll look again later, but they seem innocuous.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/29/2015 09:06 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430918#msg1430918">Quote from: graybeardsyseng on 09/29/2015 05:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430910#msg1430910">Quote from: aero on 09/29/2015 05:12 PM</a>
Regarding the null test. Aren't we pretty sure that a cylindrical resonator will not thrust? It will heat and do all the other things, but if something is escaping, that something should escape symmetrically, no thrust. If nothing is escaping then still no thrust due to symmetry.

Of course getting the heating rates right may be a little tricky when it comes to comparing to a real EM Drive configuration.

I do think the idea posted much earlier by (I forget who posted it), the idea of two identical frustums, one at each end of a balance beam, would go a long way toward eliminating thermal lift from the data. The idea was to mount both frustums upward, run to steady state then turn one off. Or mount one up, one down and run synchronously, doubling the thrust effect while significantly reducing the lift effect. This one would allow data collection from initial power on of the cold system and still reduce the effect of thermal lift.

Only problem is that it takes two frustums, but rfmwguy can tell us how much difficulty and cost would be involved in building the second identical frustum. And he could likely scope out the required modifications to the test rig as well.

And the difficulty with the word "identical"  meaning identical fabrication, feeding, power coupled etc.     Not easy.  Do-able, but not easy.
H

As has been mentioned, identical is good, but not necessary. They just need to be close enough that the second frustum mimics the thermal lift better than a hot plate and also better than nothing. The objective is to counterbalance the thermal effects in order to reduce the unbalanced thermal lift while adding to the the EM drive effect. This should pull the EM drive effect up out of the, now reduced, thermal noise.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/29/2015 09:09 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430973#msg1430973">Quote from: glennfish on 09/29/2015 08:49 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430963#msg1430963">Quote from: rfmwguy on 09/29/2015 07:59 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430947#msg1430947">Quote from: glennfish on 09/29/2015 07:05 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430943#msg1430943">Quote from: rfmwguy on 09/29/2015 06:39 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430941#msg1430941">Quote from: glennfish on 09/29/2015 06:26 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430931#msg1430931">Quote from: rfmwguy on 09/29/2015 06:03 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430920#msg1430920">Quote from: glennfish on 09/29/2015 05:25 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430899#msg1430899">Quote from: rfmwguy on 09/29/2015 04:42 PM</a>
@glennfish, attached is the original ft 2d spreadsheet with data channels 2-4 (columns b-d) unhidden. Its in the original file as well, just hidden.

Note on these hidden data channels: The data inputs are unloaded, meaning nothing is attached to them, unlike channel 1 (column a on the spreadsheet), the LDS voltage input. This might be useful in looking at system noise in mag ON/OFF conditions.

While I cannot quantify the randomness, it will be the most variable (very sensitive) since there is no load (resistor) on the inputs. If mag ON imparts system noise, these 3 channels and over 8,100 data points will be the most sensitive to noise and will show it.

Another note. The balanced impedance of channel 1 is 470 ohms. Data on channels 2-4 (columns b-c) are open (infinite impedance by comparison) and are not directly equivalent to channel 1. However general deviation comparisons to mag ON/OFF should give you a relative indication of any system noise attributable to EMI, if present.

Thank you.  Now ponder this with me  (before I downloaded your data):

1. The data trend overall is a negative slope.
2.  You suggested in the last 24 hours that -- the turn-on time to resonance could be seconds
3.  So what I did is for each group (on or off), asked, "was the first half of the slope > the 2nd half of the slope?"     i.e. was there a slope change from negative to more negative about midpoint in the interval?

Preliminary results

For off groups, that was true 14 out of 47 times
For on groups, that was true 29 out of 47 times

For results, Fisher's exact test for those wanting to learn stats...  :)

I have to check my work a few times, and when I do, I'll upload the analysis.

I've confused myself.  Would this result be a good thing or a bad thing?
Its a good thing, as it confirms the hypothesis that ON does not provide instantaneous results, as in a square-wave voltage change. Mag heating, frequency and resonance shift all combine (my belief) for variances shown in the points you made above. On the other hand, mag OFF is rather calm and predictable, with mother nature taking over and gently thermal lifting the DUT.

Not sure if the 50% point is the best point to sub-divide, but the ON state variances versus the OFF state variances is a decent way to look at the data subset.

OK spreadsheet with analysis (no VBA)

Sheet:  raw.php
    raw data and processing

Sheet:  Sheet1
    summary & results

               m1>m2   m1<=m2        
Group ON       29                18        
Group OFF       14                33        

Fisher's exact test, two tailed p = .0035
Fisher's exact test, one tailed p = .0018
Nice glenn, for us stat-light posters out here, what does the data tell you?

stat-light... sounds like a beer :)

OK, there is a very significant difference between the slope behavior for on vs. off, given by the values of p.  Close to 1 is bad.  Close to 0 is good.

What this indicates is:

If ON, the slope is likely to become more negative during the cycle.
If OFF, the slope is likely to not change or become less negative during the cycle.

examples
              define m1 as the slope during the 1st half of the cycle and m2 as the slope during the last half of the cycle.
              if m1 = -2 and m2 = -3   then m1>m2 = TRUE
              if m1 = -2 and m2 = -1   then m1>m2 = FALSE
Ok, more confirmation of ON cycle changes. Looks like all roads leading to the conclusion that something is definitely happening, i.e. not a null test...positive not null. Fair statement?

I've been OCD like on not calling this effect thrust, and guess I will continue to do so. Without a true understanding of why this happens, it might as well be an attractive or repulsive force. Not 100% comfortable with thrust, so my shorthand is emdrive effect.

Guess a last piece of the puzzle is the open channel data points for relative system noise comparisons betwee on/off states. A quick glance, saw nothing significant in the numbers indicating an EMI induced spike or noise. Let me know if you concur.


Physics isn't my strong suit.  Simply put, when power is on, things are different than when power is off.  The data supports that. 

You have shared your data, and others here have shared their data and analysis.  It's fair game for anyone with an internet connection to review, critique, replicate, or ignore.

re the noise numbers in those other channels, I haven't looked extensively but a quick look shows they seem rather random.  I did a couple of quick correlation analyses and the rs were in the .00x range.  There are only a few discrete values and they look like the lowest possible DAC's deviation from a ground state.  They are definitely not correlated with your actual data.  I'll look again later, but they seem innocuous.
Thanks again for all your hard work Glenn, it is greatly appreciated. As you said, I could find no correlation in noise to power on, it did seem random to me. I did take the time to do a rough overlay against an image provided by another poster (think it was Joe). Its shows all noise datapoints highly scattered regardless of on or off.

Readers should note that it is highly exaggerated (blue dots) in the Y axis showing is extremely small voltage changes in one of the open channels of the DAQ. So, highly exaggerated noise versus a beam deflection and power ON (pink lines) of FT 2D.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 09/29/2015 10:33 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430977#msg1430977">Quote from: aero on 09/29/2015 09:06 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430918#msg1430918">Quote from: graybeardsyseng on 09/29/2015 05:23 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430910#msg1430910">Quote from: aero on 09/29/2015 05:12 PM</a>
Regarding the null test. Aren't we pretty sure that a cylindrical resonator will not thrust? It will heat and do all the other things, but if something is escaping, that something should escape symmetrically, no thrust. If nothing is escaping then still no thrust due to symmetry.

Of course getting the heating rates right may be a little tricky when it comes to comparing to a real EM Drive configuration.

I do think the idea posted much earlier by (I forget who posted it), the idea of two identical frustums, one at each end of a balance beam, would go a long way toward eliminating thermal lift from the data. The idea was to mount both frustums upward, run to steady state then turn one off. Or mount one up, one down and run synchronously, doubling the thrust effect while significantly reducing the lift effect. This one would allow data collection from initial power on of the cold system and still reduce the effect of thermal lift.

Only problem is that it takes two frustums, but rfmwguy can tell us how much difficulty and cost would be involved in building the second identical frustum. And he could likely scope out the required modifications to the test rig as well.

And the difficulty with the word "identical"  meaning identical fabrication, feeding, power coupled etc.     Not easy.  Do-able, but not easy.
H

As has been mentioned, identical is good, but not necessary. They just need to be close enough that the second frustum mimics the thermal lift better than a hot plate and also better than nothing. The objective is to counterbalance the thermal effects in order to reduce the unbalanced thermal lift while adding to the the EM drive effect. This should pull the EM drive effect up out of the, now reduced, thermal noise.

True enough - it would definitely allow for a much better signal to noise ratio.   But regardless of how well it could be compensated for and used to boost S/N I suspect that the non-identical nature of the two drives would become a new source of doubt for some folks.   Definitely worth doing though as I think the better S/N would present a much clearer picture.

Even if I go with a rotating table approach, one set of tests I want to run is frustum v frustum - sort of a mano a mano UFC challenge for propellentless thrust.   (sorry - been a long day wading through Medicare paperwork - you haven't lived until you have done that). 

H

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 09/29/2015 11:44 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431015#msg1431015">Quote from: graybeardsyseng on 09/29/2015 10:33 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430977#msg1430977">Quote from: aero on 09/29/2015 09:06 PM</a>

Quote
And the difficulty with the word "identical"  meaning identical fabrication, feeding, power coupled etc.     Not easy.  Do-able, but not easy.
H

As has been mentioned, identical is good, but not necessary. They just need to be close enough that the second frustum mimics the thermal lift better than a hot plate and also better than nothing. The objective is to counterbalance the thermal effects in order to reduce the unbalanced thermal lift while adding to the the EM drive effect. This should pull the EM drive effect up out of the, now reduced, thermal noise.

True enough - it would definitely allow for a much better signal to noise ratio.   But regardless of how well it could be compensated for and used to boost S/N I suspect that the non-identical nature of the two drives would become a new source of doubt for some folks.   Definitely worth doing though as I think the better S/N would present a much clearer picture.

Even if I go with a rotating table approach, one set of tests I want to run is frustum v frustum - sort of a mano a mano UFC challenge for propellentless thrust.   (sorry - been a long day wading through Medicare paperwork - you haven't lived until you have done that). 

H

Remember, there is always the option to evaluate each frustum by itself simply by heating them both then running one or the other but not both, to detect individual EM drive characteristics, if any. And by now, I think there might well be an effect, just need to better pull it out of the noise.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 09/30/2015 12:34 AM
for completion sake, all VBA used in my analyses is provided below. 

Since this site didn't provide the ability to upload a Microsoft Exel spreadsheet with live VBA, I've provided the code for evaluation, critique, modification, or to use on birthday cards for your mother.  It was rushed & hacked and I didn't cover all possible conditions which especially threw out the last data set, but the code corresponds to the spreadsheets that I uploaded to this forum and is mapped to the buttons.  Sorry no comments in the code.  The code depends on the data being in explicit columns. Insert or delete a column, and it dies a horrible death.  The spreadsheets that I uploaded had the correct columns in the correct place.

Until the next data run, I'm going back to lurking.


Sub Button1_Click()

' find slope

Dim i As Integer
Dim col As Integer
Dim row As Integer
Dim indata As Boolean
Dim inone As Boolean
Dim inzero As Boolean
Dim outrow As Integer
Dim three As Integer

outrow = 1

indata = False
inone = False
inzero = False

col = 8
row = 1
For i = 2 To 2721
    If Range("E" & i).Value <> "K" Then GoTo escape
   
    If Range("D" & i).Value <> Range("D" & i - 1).Value Then
       three = 3
       If Range("D" & i - 1).Value = 0 Then three = 3
       Cells(2, col).Value = "=linest(" & ColLtr(col) & three & ":" & ColLtr(col) & row - 1 & "," & ColLtr(col - 1) & three & ":" & ColLtr(col - 1) & row - 1 & ")"
        If Range("D" & i - 1).Value = 1 Then
            Sheets("Sheet1").Cells(outrow, 1).Value = Cells(2, col).Value
        Else
            Sheets("Sheet1").Cells(outrow, 2).Value = Cells(2, col).Value
            outrow = outrow + 1
        End If
        col = col + 2
        Cells(1, col).Value = "ON"
        If Range("D" & i).Value = 0 Then
            Cells(1, col).Value = "OFF"
        End If
       
        row = 3
    End If
   
     Cells(row, col - 1).Value = Range("A" & i).Value
     Cells(row, col).Value = Range("B" & i).Value
     row = row + 1

       
escape:
Next i

End Sub


Sub Button2_Click()

'average displacement

Dim i As Integer
Dim col As Integer
Dim row As Integer
Dim indata As Boolean
Dim inone As Boolean
Dim inzero As Boolean
Dim outrow As Integer
Dim three As Integer
Dim stuff As String
Dim started As Boolean

started = False


outrow = 1

indata = False
inone = False
inzero = False

col = 8
row = 1
For i = 2 To 2721
    If Range("E" & i).Value <> "K" Then GoTo escape
   
    If Range("D" & i).Value <> Range("D" & i - 1).Value Then
       three = 3
       If Range("D" & i - 1).Value = 0 Then three = 3
       stuff = "=(max(" & ColLtr(col) & three & ":" & ColLtr(col) & row - 1 & ")- min(" & ColLtr(col) & three & ":" & ColLtr(col) & row - 1 & "))/" & row - 3
        If started Then Cells(2, col).Value = stuff
        started = True
         If Range("D" & i - 1).Value = 1 Then
            Sheets("Sheet1").Cells(outrow, 1).Value = Cells(2, col).Value
        Else
            Sheets("Sheet1").Cells(outrow, 2).Value = Cells(2, col).Value
            outrow = outrow + 1
        End If
        col = col + 2
        Cells(1, col).Value = "ON"
        If Range("D" & i).Value = 0 Then
            Cells(1, col).Value = "OFF"
        End If
       
        row = 3
    End If
   
     Cells(row, col - 1).Value = Range("A" & i).Value
     Cells(row, col).Value = Range("B" & i).Value
     row = row + 1

       
escape:
Next i

End Sub



Sub Button3_Click()

'coefficient of variation

Dim i As Integer
Dim col As Integer
Dim row As Integer
Dim indata As Boolean
Dim inone As Boolean
Dim inzero As Boolean
Dim outrow As Integer
Dim three As Integer
Dim stuff As String
Dim started As Boolean

started = False


outrow = 1

indata = False
inone = False
inzero = False

col = 8
row = 1
For i = 2 To 2721
    If Range("E" & i).Value <> "K" Then GoTo escape
   
    If Range("D" & i).Value <> Range("D" & i - 1).Value Then
       three = 3
       If Range("D" & i - 1).Value = 0 Then three = 3
       stuff = "=stdev(" & ColLtr(col) & three & ":" & ColLtr(col) & row - 1 & ")/" & "average(" & ColLtr(col) & three & ":" & ColLtr(col) & row - 1 & ")"
        If started Then Cells(2, col).Value = stuff
        started = True
         If Range("D" & i - 1).Value = 1 Then
            Sheets("Sheet1").Cells(outrow, 1).Value = Cells(2, col).Value
        Else
            Sheets("Sheet1").Cells(outrow, 2).Value = Cells(2, col).Value
            outrow = outrow + 1
        End If
        col = col + 2
        Cells(1, col).Value = "ON"
        If Range("D" & i).Value = 0 Then
            Cells(1, col).Value = "OFF"
        End If
       
   nbsp;     row = 3
    End If
   
     Cells(row, col - 1).Value = Range("A" & i).Value
     Cells(row, col).Value = Range("B" & i).Value
     row = row + 1

       
escape:
Next i
End Sub


Sub Button4_Click()

' compare 1st half of sequence with 2nd half

Dim i As Integer
Dim col As Integer
Dim row As Integer
Dim indata As Boolean
Dim inone As Boolean
Dim inzero As Boolean
Dim outrow As Integer
Dim three As Integer
Dim half As Integer

outrow = 1

indata = False
inone = False
inzero = False

col = 8
row = 1
For i = 2 To 2721
    If Range("E" & i).Value <> "K" Then GoTo escape
   
    If Range("D" & i).Value <> Range("D" & i - 1).Value Then
       three = 3
       If Range("D" & i - 1).Value = 0 Then three = 3
       half = (row - 4) / 2
       Cells(2, col).Value = "=linest(" & ColLtr(col) & three & ":" & ColLtr(col) & half + three & "," & ColLtr(col - 1) & three & ":" & ColLtr(col - 1) & half + three & ")>linest(" & ColLtr(col) & three + half + 1 & ":" & ColLtr(col) & row - 1 & "," & ColLtr(col - 1) & three + half + 1 & ":" & ColLtr(col - 1) & row - 1 & ")"
        If Range("D" & i - 1).Value = 1 Then
            Sheets("Sheet1").Cells(outrow, 1).Value = Cells(2, col).Value
        Else
            Sheets("Sheet1").Cells(outrow, 2).Value = Cells(2, col).Value
            outrow = outrow + 1
        End If
        col = col + 2
        Cells(1, col).Value = "ON"
        If Range("D" & i).Value = 0 Then
            Cells(1, col).Value = "OFF"
        End If
       
        row = 3
    End If
   
     Cells(row, col - 1).Value = Range("A" & i).Value
     Cells(row, col).Value = Range("B" & i).Value
     row = row + 1

       
escape:
Next i
End Sub

Function ColLtr(ByVal iCol As Long, Optional sCol As String = "") As String
    ' shg 2012
    If iCol = 0 Then
        ColLtr = sCol
    Else
        sCol = Chr(65 + (iCol - 1) Mod 26) & sCol
        iCol = (iCol - 1) \ 26
        ColLtr = ColLtr(iCol, sCol)
    End If
End Function
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ThinkerX on 09/30/2015 01:36 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430850#msg1430850">Quote from: SteveD on 09/29/2015 02:26 PM</a>
A while back, somebody noted an experiment that showed thrust by bouncing a laser back and forth.  Was this a photonic laser rocket (cool tech, well understood) or did you mean it showed thrust by bouncing a laser off several mirrors and measuring the thrust at the last mirror.  If so, can you post a link to the paper or report?

That was probably me.  I have suspected Since blundering across David Bae's work most of a year ago that it contains part of the key as to what is going on with the EM Drive.

Bae's website:

 http://ykbcorp.com/tech_precFormation.html

Article:

http://www.centauri-dreams.org/?p=29341

Test result from May 2015:

http://www.popularmechanics.com/space/a15545/photonic-laser-thrust-space-engine/

Links to papers:

http://www.thelivingmoon.com/41pegasus/02files/PLT_Photonic_Laser_Thruster_01.html

What gets me here is this 'photon recycling scheme' produces output power on the order of 5000 times that of the input power - which as I understand such things, is either 'free energy territory' or dang close to it.  Yet, the effects are well supported by laboratory work, and supposedly COE is not violated.

Which leads me to wonder: if the EM Drive is somehow doing something similar to Bae's device, would that constitute a COE violation?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/30/2015 02:42 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431085#msg1431085">Quote from: ThinkerX on 09/30/2015 01:36 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430850#msg1430850">Quote from: SteveD on 09/29/2015 02:26 PM</a>
A while back, somebody noted an experiment that showed thrust by bouncing a laser back and forth.  Was this a photonic laser rocket (cool tech, well understood) or did you mean it showed thrust by bouncing a laser off several mirrors and measuring the thrust at the last mirror.  If so, can you post a link to the paper or report?

That was probably me.  I have suspected Since blundering across David Bae's work most of a year ago that it contains part of the key as to what is going on with the EM Drive.

Bae's website:

 http://ykbcorp.com/tech_precFormation.html

Article:

http://www.centauri-dreams.org/?p=29341

Test result from May 2015:

http://www.popularmechanics.com/space/a15545/photonic-laser-thrust-space-engine/

Links to papers:

http://www.thelivingmoon.com/41pegasus/02files/PLT_Photonic_Laser_Thruster_01.html

What gets me here is this 'photon recycling scheme' produces output power on the order of 5000 times that of the input power - which as I understand such things, is either 'free energy territory' or dang close to it.  Yet, the effects are well supported by laboratory work, and supposedly COE is not violated.

Which leads me to wonder: if the EM Drive is somehow doing something similar to Bae's device, would that constitute a COE violation?
Thanks, had not studied this concept. 5K power increase? Going to have to read his papers closely, also beam confinement seems unlikely, but am open to read up. Trying to think of any energy that would play by these rules. Rf would need guides to contain it or it would instantly scatter. Additive? Now that's interesting.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Tellmeagain on 09/30/2015 03:36 AM
Where is our friend Rodal? It seems he has been quiet for half a month.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 09/30/2015 04:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431110#msg1431110">Quote from: Tellmeagain on 09/30/2015 03:36 AM</a>
Where is our friend Rodal? It seems he has been quiet for half a month.

I believe he is around just in lurking mode. Dr. Rodal follows EmDrive debate from the start, so in my opinion he also needs some time to focus on different things and some rest from this debate :). I also believe we may see many folks returing once we see data from NASA EW by the end of this year.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: zero123 on 09/30/2015 05:08 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431085#msg1431085">Quote from: ThinkerX on 09/30/2015 01:36 AM</a>
What gets me here is this 'photon recycling scheme' produces output power on the order of 5000 times that of the input power - which as I understand such things, is either 'free energy territory' or dang close to it.  Yet, the effects are well supported by laboratory work, and supposedly COE is not violated.

Which leads me to wonder: if the EM Drive is somehow doing something similar to Bae's device, would that constitute a COE violation?

There's no COE violation because as the photons bounce between the two mirrors, the speed of the mirrors relative to each other will increase as per the momentum change imparted by the reflected photon. This in turn means that the photons will get more and more red-shifted. This ensures that total kinetic energy gained can never exceed the energy spent on producing the photons. 

So, yes, it is more efficient than a simple photon drive but it only works if the mirrors are actually moving away from each other faster and faster after each bounce and this increase of speed must match the imparted momentum by each bounce. In the EMdrive case the photons are bouncing between the walls of the drive and the walls clearly don't increase their speed relative to each other in such a fashion, so it is a completely different situation.

Title: EM Drive Developments - related to space flight applications - Thread 4
Post by: Star One on 09/30/2015 07:15 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431136#msg1431136">Quote from: Chrochne on 09/30/2015 04:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431110#msg1431110">Quote from: Tellmeagain on 09/30/2015 03:36 AM</a>
Where is our friend Rodal? It seems he has been quiet for half a month.

I believe he is around just in lurking mode. Dr. Rodal follows EmDrive debate from the start, so in my opinion he also needs some time to focus on different things and some rest from this debate :). I also believe we may see many folks returing once we see data from NASA EW by the end of this year.

Can we be so sure of hearing anything from NASA EW within that timeframe, I'm not after past events?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/30/2015 12:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431162#msg1431162">Quote from: Star One on 09/30/2015 07:15 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431136#msg1431136">Quote from: Chrochne on 09/30/2015 04:58 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431110#msg1431110">Quote from: Tellmeagain on 09/30/2015 03:36 AM</a>
Where is our friend Rodal? It seems he has been quiet for half a month.

I believe he is around just in lurking mode. Dr. Rodal follows EmDrive debate from the start, so in my opinion he also needs some time to focus on different things and some rest from this debate :). I also believe we may see many folks returing once we see data from NASA EW by the end of this year.

Can we be so sure of hearing anything from NASA EW within that timeframe, I'm not after past events?
Only rumors from last year that new testing will be done by this past summers end. Lets cross our fingers.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/30/2015 12:51 PM

When I started posting on the NSF blog months ago there was chat that EagleWorks was going to have results and a paper by the end of July. Ya, well it may happen, when Santa delivers his toys. I know the poo storm they started on the last release and all I would say is that had to be viewed as bad publicity for NASA and I heard hear they were told to shut up and then went dark.
A new report, new data? I don't know, maybe it's the same soup in a different can, but new and improved... with a fresher scent and longer lasting.

Honestly, I'm not going to keep my hopes up too high for anything from EW anytime soon or ever, if anything comes from them it's going to be under a microscope and heat right from the start and it better be rock solid and able to withstand the instant criticism from people who are waiting to pounce.

Other than that, I'm sorry I have been a little quiet but I'm right in the grove of building this drive and the devil is in the details. Unlike the superstars over at EW or some of the Universities, what data I (just me with some great help from other here) get had better be of a bullet proof nature.

I want to thank the group here for data mining rfmwguy's test (IMPRESSIVE!) and for him giving me hope that  there just might be something there, just maybe and it's a big maybe I can get just a little cleaner data. My goal is to try to get this thing that's seen as thrust out of the noise and issues of thermal deviation of test data.

Shell

PS: Finally figured out a way to be able to fine tune the 2 plates in the test phase with VNA data and even during  power tests (off times) to be able to sweep the distance between the end cavities. The .5" quartz rod I'm using between the plates and captured in the large bottom plate. It not only allows the distance to be adjusted between the plates but will also keep the tune distance allowing the sidewalls of the frustum to slide past the top plate has been solved.

Using scavenged parts from an old SEM controls I'm attaching the quartz rod to one of the micrometer bodies to run up through the center of the frustum. This sits in the center of the Large plate.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/30/2015 01:08 PM

You are my hero, even tho your Mercedes Turbo Coup design makes mine look like a VW beetle.  8)

Godspeed in your build and tests. Thanks so much for the pics...you know, you have to take over for me for a while in pic & vid postings...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/30/2015 01:41 PM
Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.

Our best to you.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Flyby on 09/30/2015 01:56 PM
I've seen a few "like"s he made on some topics in the past 12 days, so Dr Rodal is still following the forum...
Consequently, I don't think there is a medical problem, like it was the case with TT going offline...

It just adds a bit more mystery... :o... certainly when you realize he has been posting several times per day ever since this topic started...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: TheTraveller on 09/30/2015 02:16 PM
I've started my radiation treatment, which should complete end Nov 2015. If that works as expected, maybe 2-3 weeks later can get back to doing my build. If not clear, I'll start chemo.

I say again. Guys get your prostate checked. This cancer has almost no signals, except for increased PSA and reduced flow, but in 30% of cases, PSA is not that elevated. Mine was 3.7 and the left half of my prostate was full of Gleason 9 cancer that had grown outside the prostate.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/30/2015 02:42 PM

Hum I've got one of Bae's papers.  Let me jump to the important bit

Quote
Under the auspice of NIAC/NASA, the author successfully demonstrated the proof-of-concept of a
PLT. [3,16] In this demonstration, a PLT was built from off-the-shelf optical components and a YAG
gain medium, and the maximum amplified photon thrust achieved was 35 μN for a laser output of 1.7 W
with the use of a HR mirror with a 0.99967 reflectance. This performance corresponds to an apparent
photon thrust amplification factor of ~3,000. More importantly, in the experimental demonstration, the
author accidentally discovered that the PLT cavity is highly stable against the mirror motion and
misalignment unlike passive optical cavities. In fact, in the demonstration experiment by the author, the
full resonance mode of the PLT was discovered to maintain even when one of the HR mirror was held,
moved, and tilted by a hand to the author’s surprise.
In a more systematic experiment, the PLT cavity
was systematically demonstrated to be highly stable against tilting, vibration and motion of mirrors.
Subsequent theoretical analysis by the author showed that PLT can indeed be used for propulsion
applications, and proposed Photonic Laser Propulsion (PLP), the propulsion with PLT. [15] The reason
for the observed stability results from that in the active optical cavities for PLT and PLP the laser gain
medium dynamically adapts to the changes in the cavity parameters, such as mirror motion, vibration and
tilting, which does not exist in the passive optical cavities.


I've included a diagram of a conventional laser and of a proposed photonic laser thruster to make what the author of the paper is doing a bit more clear.

Um hum, if the author can maintain an optical :o resonance by hand holding a mirror, then the gain medium must be capable of both redshifting and blueshifting the wavelength of the photon.  Well I suppose the gain medium is receiving photons from both ends so it has some way of knowing what the resonant frequency is.  I'd also note that, if the device only has to be in the ballpark of the right dimensions and the gain medium fixes the frequency for you, that would help to explain the functioning of every cheap $10 laser pointer ever made.

For an EMDrive, I wonder what would happen if you put a microwave gain media and a pump inside the cavity.  The gain media could either be a gas or a solid state media.  I wonder how big you could get a solid state media.  While I've read the almost all solid state gain media for a Maser need cryogenic cooling to work, if you have a superconductor on one end of the cavity you already need that cooling.

Hum according to some reading: Ammonia works as a gain medium at a frequency around where the hackaday EMDrive resonates and hydrogen can be a gain medium around 1.4ghz.

Can I jump up and down a couple times and say that I think Bae's observation is important.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: sghill on 09/30/2015 02:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431227#msg1431227">Quote from: SeeShells on 09/30/2015 01:41 PM</a>
Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.

Our best to you.

Shell

I spoke with him yesterday.  He's here.  He's fine.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chrochne on 09/30/2015 03:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431246#msg1431246">Quote from: sghill on 09/30/2015 02:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431227#msg1431227">Quote from: SeeShells on 09/30/2015 01:41 PM</a>
Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.

Our best to you.

Shell

I spoke with him yesterday.  He's here.  He's fine.


That "like" by Dr. Rodal now, was better shock than first beep of the Sputnik over the USA  ;D

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/30/2015 04:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431230#msg1431230">Quote from: Flyby on 09/30/2015 01:56 PM</a>
I've seen a few "like"s he made on some topics in the past 12 days, so Dr Rodal is still following the forum...
Consequently, I don't think there is a medical problem, like it was the case with TT going offline...

It just adds a bit more mystery... :o... certainly when you realize he has been posting several times per day ever since this topic started...

This is also the point in the Fall semester where students have their first set of tests/things due. 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/30/2015 04:29 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431246#msg1431246">Quote from: sghill on 09/30/2015 02:58 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431227#msg1431227">Quote from: SeeShells on 09/30/2015 01:41 PM</a>
Dr. Rodel, the troops would like a "I'm here and fine". Believe it when I say, we all miss your posts. But I understand when other life issues (maybe by making a living) take front stage.

Our best to you.

Shell

I spoke with him yesterday.  He's here.  He's fine.
Doc, ya had me scared for a second, just when my experiment went into hibernation after successful testing. I was hoping it had not inadvertedly beam you off-planet throught some sort of spacetime collapse or something  ;)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 09/30/2015 04:45 PM
Hum, plugging along when I should be doing something else.  Here is a visualization of a https://en.wikipedia.org/wiki/Whispering-gallery_wave (https://en.wikipedia.org/wiki/Whispering-gallery_wave) resonator.  I can't help but notice that the wave pattern looks very much like the "nodules" that appeared on the MEEP output of the big base of CE-3.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 09/30/2015 07:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431296#msg1431296">Quote from: SteveD on 09/30/2015 04:45 PM</a>
Hum, plugging along when I should be doing something else.  Here is a visualization of a https://en.wikipedia.org/wiki/Whispering-gallery_wave (https://en.wikipedia.org/wiki/Whispering-gallery_wave) resonator.  I can't help but notice that the wave pattern looks very much like the "nodules" that appeared on the MEEP output of the big base of CE-3.

This the one? ;)

Added...
A thumbs up for who can tell me this mode....

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 09/30/2015 08:50 PM
"Peer" review anyone?

I am ready to present my Paper on the NSF-1701 experiment. To keep with the spirit of scientific research, I would like to have it reviewed by fellow posters here. The only thing I ask is you take the time to read it and critique content, layout, spelling, anything you want.

I can credit you with a review on the paper if you want or not. That is up to you. PM me with the request to "peer review" think I'll need an email addess to send the file.

Dave
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Asteroza on 09/30/2015 11:45 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431241#msg1431241">Quote from: SteveD on 09/30/2015 02:42 PM</a>

For an EMDrive, I wonder what would happen if you put a microwave gain media and a pump inside the cavity.  The gain media could either be a gas or a solid state media.  I wonder how big you could get a solid state media.  While I've read the almost all solid state gain media for a Maser need cryogenic cooling to work, if you have a superconductor on one end of the cavity you already need that cooling.

Can I jump up and down a couple times and say that I think Bae's observation is important.

There was that recent discovery of solid state non-cryogenic masers using an organic crystal of sorts.

http://www.nature.com/nature/journal/v488/n7411/full/nature11339.html (http://www.nature.com/nature/journal/v488/n7411/full/nature11339.html)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/01/2015 12:12 AM
NSF-1701 paper review...Thanks, I've sent out several sets, and could probably use about 7 more reviewers...PM me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/01/2015 09:52 PM
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: ort on 10/01/2015 10:01 PM
Since its been quiet in here today.  I'd just like to offer congrats on the build and the experimental runs so far.  Back to lurking and observing...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: R.W. Keyes on 10/01/2015 10:57 PM
Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.

What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 12:11 AM
Sometimes you need a day, I took it today. I live in the Colorado Rockies and this time of year is afire with the leaves changing and good friends you haven't visited for awhile to simply visit. Dusted off the old 65 Pontiac and did just that. Got away from the building the EMDrive and test bed and enjoyed what little there is left of warm weather.

No new news today from the build, sorry... but the old gal building it feels much better!

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/02/2015 12:45 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431883#msg1431883">Quote from: R.W. Keyes on 10/01/2015 10:57 PM</a>
Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.

What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
You understand the situation well. My frustum was a collaboration of people here giving me specs on a design not using a dielectric. I believe it worked good enough to convince me to design and build next year.

I took a shotgun approach with a broadband magnetron spewing RF in to a cavity. The way I determined the match was good enough was carefully monitoring magnetron temperatures. I believe my frustum does resonate, but the Q is likely below 1000.

That being said, high Q proponents have to realize a phase lock or auto-tune system MUST be used to keep the CW signal (not broadband mag) locked at resonance. Any loss of lock on the resonance will result in immediate high standing waves damaging the source or dumping the reflections into a load (circulator) which means there is low RF applied to the frustum.

So, bottom line, there is probably a limit to what us DIY types can hope for. Cryogenic designs burn money faster than a sailor on shore leave. Or me in a microbrewery.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 10/02/2015 01:48 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

Looked over the spreadsheet and charts  for a bit tonight - I think you are on to something in your interpretation.  Concur that at least 75% of ON/OFF appear to have SOMETHING different happening in the ON portion.

 I'm rusty on my statistics but I think there are some noise or noise randomness metrics that might be applied comparing between OFF times ON/OFF time.  Maybe someone more up on the magic of stat analy ( and probably more awake) can do something definitive with this beyond the just visual interpretation.

  But kudos to Kashua !!! nice piece of work.  And I there is much here to glean for future builds - I will examine WRT my plans tomorrow after sleep.
H.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 10/02/2015 01:53 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431896#msg1431896">Quote from: SeeShells on 10/02/2015 12:11 AM</a>
Sometimes you need a day, I took it today. I live in the Colorado Rockies and this time of year is afire with the leaves changing and good friends you haven't visited for awhile to simply visit. Dusted off the old 65 Pontiac and did just that. Got away from the building the EMDrive and test bed and enjoyed what little there is left of warm weather.

No new news today from the build, sorry... but the old gal building it feels much better!

Shell

Good on you! Excellent way to recharge the batteries. 

My father passed on some words of wisdom years ago concerning retirement which I am just now finding out the value of.   He said - "Retirement is every day.  Its continuous, no weekends or holidays.  So every once in a while you have to make sure you take a day off." 

I find - when I am not sure what day of the week it is - its time for a day off.

H.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 02:01 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431910#msg1431910">Quote from: graybeardsyseng on 10/02/2015 01:53 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431896#msg1431896">Quote from: SeeShells on 10/02/2015 12:11 AM</a>
Sometimes you need a day, I took it today. I live in the Colorado Rockies and this time of year is afire with the leaves changing and good friends you haven't visited for awhile to simply visit. Dusted off the old 65 Pontiac and did just that. Got away from the building the EMDrive and test bed and enjoyed what little there is left of warm weather.

No new news today from the build, sorry... but the old gal building it feels much better!

Shell

Good on you! Excellent way to recharge the batteries. 

My father passed on some words of wisdom years ago concerning retirement which I am just now finding out the value of.   He said - "Retirement is every day.  Its continuous, no weekends or holidays.  So every once in a while you have to make sure you take a day off." 

I find - when I am not sure what day of the week it is - its time for a day off.

H.
OMG... I woke up this morning thinking it was Monday. Point on.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/02/2015 02:14 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431909#msg1431909">Quote from: graybeardsyseng on 10/02/2015 01:48 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

Looked over the spreadsheet and charts  for a bit tonight - I think you are on to something in your interpretation.  Concur that at least 75% of ON/OFF appear to have SOMETHING different happening in the ON portion.

 I'm rusty on my statistics but I think there are some noise or noise randomness metrics that might be applied comparing between OFF times ON/OFF time.  Maybe someone more up on the magic of stat analy ( and probably more awake) can do something definitive with this beyond the just visual interpretation.

  But kudos to Kashua !!! nice piece of work.  And I there is much here to glean for future builds - I will examine WRT my plans tomorrow after sleep.
H.
I told Kasuha that I would have never thought of speed and acceleration in a balance beam measurement, only straight line linear. But, if what I think is happening, the deceleration during ON is a good way to carve out data from lift.

However, a more precise clock will be needed for better resolution...will ponder that for several weeks I'm sure.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 02:29 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431917#msg1431917">Quote from: rfmwguy on 10/02/2015 02:14 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431909#msg1431909">Quote from: graybeardsyseng on 10/02/2015 01:48 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

Looked over the spreadsheet and charts  for a bit tonight - I think you are on to something in your interpretation.  Concur that at least 75% of ON/OFF appear to have SOMETHING different happening in the ON portion.

 I'm rusty on my statistics but I think there are some noise or noise randomness metrics that might be applied comparing between OFF times ON/OFF time.  Maybe someone more up on the magic of stat analy ( and probably more awake) can do something definitive with this beyond the just visual interpretation.

  But kudos to Kashua !!! nice piece of work.  And I there is much here to glean for future builds - I will examine WRT my plans tomorrow after sleep.
H.
I told Kasuha that I would have never thought of speed and acceleration in a balance beam measurement, only straight line linear. But, if what I think is happening, the deceleration during ON is a good way to carve out data from lift.

However, a more precise clock will be needed for better resolution...will ponder that for several weeks I'm sure.

I really like the way he did the speed and acceleration work up, nice work! It seems with each evaluation adding credence to thrust results, up and out of the noise. Gives me hope I can come close to your tests. Nice work rfmwguy and for those that are doing the data evaluation a huge thumbs up.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Tellmeagain on 10/02/2015 03:31 AM
I have just submitted our paper to a journal for peer review. Let's see.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Mezzenile on 10/02/2015 06:03 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1430977#msg1430977">Quote from: aero on 09/29/2015 09:06 PM</a>
As has been mentioned, identical is good, but not necessary. They just need to be close enough that the second frustum mimics the thermal lift better than a hot plate and also better than nothing. The objective is to counterbalance the thermal effects in order to reduce the unbalanced thermal lift while adding to the the EM drive effect. This should pull the EM drive effect up out of the, now reduced, thermal noise.
Most of the trouble with thermal dissipation comes from its natural convective heat transfer mode which entails air movement which has a random mechanical effect on the test set up. If we could reinforce the conductive and radiative modes of thermal dissipation, we should reduce the effects of convection and their random features.
To do so I see 3 possible actions:
1- Reduce as far as possible the hot temperature spots which initiate convection by using larger radiative surfaces to reduce temperature.
2- Increase radiation heat dissipation using black-body paint.
3- Prevent the formation of convection cells or chimney effect by imposing a geometrical stratification of air all along the frustum using for example horizontal sheets of aluminium or copper (minimal mass is preferable to limit the increase of the test device mechanical inertia which is not good for thrust sensitivity).

If the dual frustum configurations I proposed are certainly good for a compensation of the steady state part of the thermal effect, they will be less efficient for what concern random effects which of course are not synchronized on both frustum. The proposed design improvements should help to mitigate this problem.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: flux_capacitor on 10/02/2015 09:37 AM

McCulloch published a new peer-reviewed paper in EPL about the EmDrive:

McCulloch, M. E. (October 2015). "Testing quantised inertia on the emdrive". EPL (Europhysics Letters) 111(6): 60005. doi:10.1209/0295-5075/111/60005 (http://iopscience.iop.org/article/10.1209/0295-5075/111/60005/)


And he has just made the full text available on ResearchGate:
https://www.researchgate.net/publication/282357284_Testing_quantised_inertia_on_the_emdrive

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 11:38 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431883#msg1431883">Quote from: R.W. Keyes on 10/01/2015 10:57 PM</a>
Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.

What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
From DYIer perspective.

The Thermal Expansion Coefficient for copper is: 0.000017 (m/moC)
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thexp.html#c1

This TEC becomes a issue in the changing of the cavity length but also the warping of the hot zones within the copper at the modes points. If we were smarter we could build it of quartz (flashed with silver and gold) which is 28x less or some other 0o TEC material, but that becomes something expensive a DYier can't do.

So a DYier can do a couple things, go low power which is tough to get any readings or go higher power and try to negate by design the issue of TEC. I think the best of both worlds would be negating the TEC thru design (I've tried to do) ... and make it superconducting but I'm going for up to 2 KW into the frustum.

Right now I'm shooting for design control of the TEC and producing a clean RF through a modified magnetron inverter and removing the hot magnetron away from the frustum and feeding the RF into the frustum via antenna or waveguide. These designs have given a very high Q but it is to be seen if I can keep the higher Qs in a real world operation.

Simple thought, lower Qs mean the incoming RF signal is absorbed into the frustum and turned into simply generating heat. Unless I want to drive this with a megawatt(s) klystron turning the frustum into a white hot effervescent accelerating stream of gas, that might give me acceleration but it's outside of the box and a simple rocket then.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 10/02/2015 12:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

I'm not sure how to interpret his results.   His calculated values include data from OFF regions, when ON, and ON regions, when OFF.   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 10/02/2015 01:02 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432097#msg1432097">Quote from: glennfish on 10/02/2015 12:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

I'm not sure how to interpret his results.   His calculated values include data from OFF regions, when ON, and ON regions, when OFF.

The more I look at the spreadsheet the more questions I am having.   He is using delta Voltage over the fixed time interval as a velocity measure then appears to be calculating a moving average of the Delta Voltage aka Velocity.   Then apparently he "smooths " this moving average by (sequentially) taking the moving average of the moving average.  His first appears to be over 10 data points, then 9, then 8 (note - I may be counting wrong - only one cup of coffee so far).

  Subsequently he  uses that last moving average for  what he calls dV(off) if the magnetron was off for more than 4 of the data points in the range of the original average and dV (ON) if Maggie was on for more than 9 of the data points of the original range. 

He then calculates a ddV for each of the last set of moving averages to calculate acceleration and does the same type on off tests (now ddV ON and ddV OFF) as he did for velocity.

Due to the nature of this process he sometimes gets a moving average number for dV or ddV ON when the magnetron is ON and likewise dV and ddV  OFF when the magnetron is ON.

Been a long time BUT IIRC there were some things you had to be careful about in smoothing data and averages of averages.

Herman
 

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/02/2015 01:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432097#msg1432097">Quote from: glennfish on 10/02/2015 12:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

I'm not sure how to interpret his results.   His calculated values include data from OFF regions, when ON, and ON regions, when OFF.
It was a bit difficult from me as well, although I think he might be on to something about the acceleration analysis. Thermal lift will want to stabilize at a certain velocity and a power on condition should cause that velocity to change. Not sure how to set up the delta V/delta T formulas. Unfortunately the time stamp resolution is only 1 second, so rather poor resolution for a proper speed/velocity reading.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 10/02/2015 02:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432109#msg1432109">Quote from: rfmwguy on 10/02/2015 01:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432097#msg1432097">Quote from: glennfish on 10/02/2015 12:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

I'm not sure how to interpret his results.   His calculated values include data from OFF regions, when ON, and ON regions, when OFF.
It was a bit difficult from me as well, although I think he might be on to something about the acceleration analysis. Thermal lift will want to stabilize at a certain velocity and a power on condition should cause that velocity to change. Not sure how to set up the delta V/delta T formulas. Unfortunately the time stamp resolution is only 1 second, so rather poor resolution for a proper speed/velocity reading.

Well just for jollies, I decided to look at the differences.  Even if I don't like his spreadsheet, it is an interesting idea.  I did some visual basic to do the following:
1. find the difference between two measurements (v) (didn't use the timestamp)
2. for each group of on or off, find the average (v) for that group
3. calculate the number of times adjacent Voff>Von and adjacent Von>=Voff

Here are the results for the 47 pairs (groups)

Voff>Von:   16
Von>=Voff: 31

The actual is about 66%, RFMWGUY was off by 9%.  Better than government contractors for sure.  :)

Let's make someone on Reddit do the stats.  :)

I'll upload the spreadsheet & VBA if anyone asks.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/02/2015 03:13 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432141#msg1432141">Quote from: glennfish on 10/02/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432109#msg1432109">Quote from: rfmwguy on 10/02/2015 01:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432097#msg1432097">Quote from: glennfish on 10/02/2015 12:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

I'm not sure how to interpret his results.   His calculated values include data from OFF regions, when ON, and ON regions, when OFF.
It was a bit difficult from me as well, although I think he might be on to something about the acceleration analysis. Thermal lift will want to stabilize at a certain velocity and a power on condition should cause that velocity to change. Not sure how to set up the delta V/delta T formulas. Unfortunately the time stamp resolution is only 1 second, so rather poor resolution for a proper speed/velocity reading.

Well just for jollies, I decided to look at the differences.  Even if I don't like his spreadsheet, it is an interesting idea.  I did some visual basic to do the following:
1. find the difference between two measurements (v) (didn't use the timestamp)
2. for each group of on or off, find the average (v) for that group
3. calculate the number of times adjacent Voff>Von and adjacent Von>=Voff

Here are the results for the 47 pairs (groups)

Voff>Von:   16
Von>=Voff: 31

The actual is about 66%, RFMWGUY was off by 9%.  Better than government contractors for sure.  :)

Let's make someone on Reddit do the stats.  :)

I'll upload the spreadsheet & VBA if anyone asks.
I ask  :D

I'd like to have folks on reddit do the stats, but since I know your qualifications...I feel comfortable with your stats. I do find many on the other forum more emotionally attached to the belief that there is nothing to the emdrive effect. While I think critique is a healthy part of the process, some of the posts there devolve into absolutism and name-calling...sad.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 10/02/2015 03:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432142#msg1432142">Quote from: rfmwguy on 10/02/2015 03:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432141#msg1432141">Quote from: glennfish on 10/02/2015 02:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432109#msg1432109">Quote from: rfmwguy on 10/02/2015 01:13 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432097#msg1432097">Quote from: glennfish on 10/02/2015 12:27 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431821#msg1431821">Quote from: rfmwguy on 10/01/2015 09:52 PM</a>
A reddit user, Kasuha, has created a very interesting spreadsheet on NSF-1701 FT2D (full test). His interpretation of the data was all noise, but without understanding the test stand particulars, he has actually shown a definitive negative drop in both speed and acceleration (of the frustum end of the balance beam) as soon as the magnetron is powered ON (those traces are Red).

Note they almost always follow the 11 second mag OFF (Blue) condition where speed and acceleration were on the rise.

Maybe this is another way to separate out the EmDrive Effect from the thermal lift. You can see lift bubbling up in between test runs when mag is OFF. The frequency and amplitide of the trace in this region is quite different that the ON/OFF period. Remember, there is Doc's oil dampening system on the beam so this is all thermal lift variations (in the Blue-only regions).

Regardless, I appreciate his work and appears to me that in 75% or more of the ON/OFF cycles, mag ON forces a drop in speed and acceleration.

He shared this openly and if this helps future experimenters, he is please to do so.

I'm not sure how to interpret his results.   His calculated values include data from OFF regions, when ON, and ON regions, when OFF.
It was a bit difficult from me as well, although I think he might be on to something about the acceleration analysis. Thermal lift will want to stabilize at a certain velocity and a power on condition should cause that velocity to change. Not sure how to set up the delta V/delta T formulas. Unfortunately the time stamp resolution is only 1 second, so rather poor resolution for a proper speed/velocity reading.

Well just for jollies, I decided to look at the differences.  Even if I don't like his spreadsheet, it is an interesting idea.  I did some visual basic to do the following:
1. find the difference between two measurements (v) (didn't use the timestamp)
2. for each group of on or off, find the average (v) for that group
3. calculate the number of times adjacent Voff>Von and adjacent Von>=Voff

Here are the results for the 47 pairs (groups)

Voff>Von:   16
Von>=Voff: 31

The actual is about 66%, RFMWGUY was off by 9%.  Better than government contractors for sure.  :)

Let's make someone on Reddit do the stats.  :)

I'll upload the spreadsheet & VBA if anyone asks.
I ask  :D

ok, this "feature" is in two parts.

On the main sheet there is a new button called derivative.  This calculates the differences and dumps them onto Sheet7

On Sheet7 is a button called find average v.  This passes through the differences and calculates the average within a group and dumps that into column I.  Column L is the paired comparisons and results are in the yellow.

Sheet9 has the new VBA code

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 10/02/2015 03:36 PM
almost forgot the stats.

courtesy:  http://stattrek.com/online-calculator/binomial.aspx
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: R.W. Keyes on 10/02/2015 03:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432091#msg1432091">Quote from: SeeShells on 10/02/2015 11:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431883#msg1431883">Quote from: R.W. Keyes on 10/01/2015 10:57 PM</a>
Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.

What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
From DYIer perspective.

The Thermal Expansion Coefficient for copper is: 0.000017 (m/moC)
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thexp.html#c1

This TEC becomes a issue in the changing of the cavity length but also the warping of the hot zones within the copper at the modes points. If we were smarter we could build it of quartz (flashed with silver and gold) which is 28x less or some other 0o TEC material, but that becomes something expensive a DYier can't do.

So a DYier can do a couple things, go low power which is tough to get any readings or go higher power and try to negate by design the issue of TEC. I think the best of both worlds would be negating the TEC thru design (I've tried to do) ... and make it superconducting but I'm going for up to 2 KW into the frustum.

Right now I'm shooting for design control of the TEC and producing a clean RF through a modified magnetron inverter and removing the hot magnetron away from the frustum and feeding the RF into the frustum via antenna or waveguide. These designs have given a very high Q but it is to be seen if I can keep the higher Qs in a real world operation.

Simple thought, lower Qs mean the incoming RF signal is absorbed into the frustum and turned into simply generating heat. Unless I want to drive this with a megawatt(s) klystron turning the frustum into a white hot effervescent accelerating stream of gas, that might give me acceleration but it's outside of the box and a simple rocket then.

MgB2 electroplated onto SiC would be pretty stable at low cryogenic temp, though. Still not easy to do. Magnetrons have messy spectrum but you can clean them up with a PLL.

It seems to me that a high-Q cavity is necessary for high power, otherwise there's going to be a lot of heat, possibly leading to mechanical failure/explosion. But unless that match is good, Q will be horribly high, leading to heat, and in the case of a superconductor, thermal runaway to disaster. So, a good design might have signal generator of adjustable power and frequency (but a good, clean sine wave), and the cavity be superconducting high-Q but have a tunable Q. At startup, power is low and Q is low. the frequency of the signal generator is tuned to the middle of resonance, then the Q is increased and power increased, and the cycle repeated until emdrive effect is strong.

This requires that the adjustment of the Q is stable, and that it be protected against thermal runaway.

If some of the about language/thought seems unclear, please excuse me, I haven't yet had my coffee

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Blaine on 10/02/2015 04:19 PM
http://www.sciencedaily.com/releases/2015/10/151002082311.htm

So, a study in Germany at the University of Konstanz have found direct measurements for the ground state of the quantum vacuum.  Haha, so, yeah, thought that would be an interesting read for everyone.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SteveD on 10/02/2015 04:30 PM
Hi guys.  I've got a bug in a spreadsheet that relates to going from real numbers to an integer.  Either I've got something wrong or something really strange is going on here. 

I did up a spreadsheet to see if the redshift from a photon reflecting off the frustum and imparting a portion of its momentum on it could cause a problem at very high Q's.  To figure this out I took the energy in one watt/second (one joule), found the energy in a single photon at a particular frequency (frequency * Plank constant) and then did (Energy in one Watt Second)/(Energy Per Photon) = Total Number of Photons.  I then found the energy being imparted to a photon rocket (1/C) or in a photon bounce (2/C), subtracted it from the total energy available and divided by total number of photons.  The answer is that, at 2.4ghz, each bounce redshifts the photon by about 16hz.  If you bounce it thousands of times, then bandwidth at high Q is going to be an issue (the only way around this problem I can see is to use a maser where the gain media wants photons on the same wavelength as the frustum generates as black body radiation, i.e. heat, as a pump).

I'm very sure of, at least, the first set of relativistic equations on the spreadsheet. They describe a photon rocket.  Enter 299792458 watts into the spreadsheet and it spits out one newton of force.  That's exactly what the peer reviewed literature says it should be (and after programming this thing I think I can see why this is so). 

Here's the problem, I said that each bounce wants to redshift the light by "about" so many hertz.  For light, one hertz is one plank constant.  The plank constant is the smallest possible unit of energy in the Universe.  It has to be an integer.

If you just look at the relativistic mass of a the energy involved, it is released at point A, travels to point B and both points A and B are acted on symmetrically by the same relativistic mass.

If ignore fractional quanta then point A gains 8hz of momentum in one direction, the wave travels, and point B gains 8hz of momentum in the opposite direction.  Both points are acted on symmetrically.

Try to combine the two and everything falls apart.  (I'll use 2.28Ghz as the example frequency because it makes the problem easy to see).  Point A emits photons.  According to relativity each photon needs to give up enough energy to the emitting point to redshift it 7.6503 hz.  The plank constant is the smallest possible unity of energy.  You can't redshift by anything but an integer.  So round up to 8hz of redshift.  That means that point A has gained more energy and thus been acted upon by a greater relativistic mass than it should.  Further, because we took extra energy out, the relativistic mass of the photons reaching point B is decrease, the mass is light.  The two points are acted upon in a non-symmetrical manner (nulling Noether which only applies to symmetrical systems).

As far as I can tell the answer to this problem involves either creating more energy to get the correct relativistic mass, violating conservation of energy, or allowing the two points to gain differing momentum, violating conservation of momentum.  (Or 3, I'm mistaken in my reasoning relating to relativistic mass). 

The most likely explanation is that I have made an error in programming my spreadsheet somewhere.  I originally thought the error related to a measuring error in one of the constants.  Then I started getting redshift of 0.6 htz, that implies a fairly large measurement error somewhere.  Since I'm pulling the photon rocket equations from published literature, the error has to be in how I'm calculating the redshift (possibly in the number of photons).   Anyone know what I should be doing to get redshift as an integer?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 10/02/2015 05:53 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432160#msg1432160">Quote from: SteveD on 10/02/2015 04:30 PM</a>


The most likely explanation is that I have made an error in programming my spreadsheet somewhere.  I originally thought the error related to a measuring error in one of the constants.  Then I started getting redshift of 0.6 htz, that implies a fairly large measurement error somewhere.  Since I'm pulling the photon rocket equations from published literature, the error has to be in how I'm calculating the redshift (possibly in the number of photons).   Anyone know what I should be doing to get redshift as an integer?

I'm not sure what you're doing, but it looks like in your Total Redshift column you're trying to make it an integer.  In fact, that hasn't happened.  You've set the display to show nothing after the decimal, but all those decimal numbers are still stored in that cell.  You just can't see them.

Your final entry on row 517 is 7,613, but if you were doing roundup integer math, it would be 8,008.

Also if that column is the core to any of your calculations, you're not using it in any calculations.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DanP on 10/02/2015 05:55 PM
Good morning.  I have been lurking and observing various emdrive communities for quite a long time.  Mostly, I wonder and read, hoping people will talk about what I'm wondering about. I tend not to ask questions because my ignorance of the subject matter is profound, but for the last few days, my curiosity has really been a source of frustration.

What is the source of the resonance in the resonance cavity?  Is the copper acting as a mirror for the microwaves, or is there some mechanism at work other than reflection?

If it is acting as a mirror, then I have some questions about an unrelated set of experiments I read about some time ago.  A group of researchers apparently made some kind of microwave mirror out of an "electrical short circuit", that they were able to vibrate over a nano-meter at 0.25c.  Doing so coaxed virtual photons into becoming actual photons, through some theorized property of the Casimir effect.  I do not fully understand what they mean by the vague term in quotes, but it seems curious regardless.


Given that the vibrations they reported are 0.25c, does this mean the surface of their microwave mirror is not a physical surface but rather some kind of field?

If the surface of their microwave mirror is not a physical surface, would it be possible to create a non-physical microwave mirror surface in an emdrive, and if so, would there be any worthwhile benefits to doing so such as greater control of resonance, a more flexible/dynamic shape, mitigation of thermal deformation, ruling out potential error sources, etc?

In either case, if an emdrive's current copper frustum is acting as a microwave mirror, is it possible that resonance is somehow creating a similar nano-scale vibration at relativistic speeds, coaxing virtual particles into becoming real particles?  If so, what would be the implications for thrust signals?

I am a software developer and not a scientist or engineer, so I am fully aware that these questions are likely quite misguided.  Still, I can only contain my curiosity for so long, and I figure there's little harm in wondering aloud once in a while.  Thank you for all the great reading over the months.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 10/02/2015 06:32 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432179#msg1432179">Quote from: DanP on 10/02/2015 05:55 PM</a>
Good morning.  I have been lurking and observing various emdrive communities for quite a long time.  Mostly, I wonder and read, hoping people will talk about what I'm wondering about. I tend not to ask questions because my ignorance of the subject matter is profound, but for the last few days, my curiosity has really been a source of frustration.

What is the source of the resonance in the resonance cavity?  Is the copper acting as a mirror for the microwaves, or is there some mechanism at work other than reflection?

If it is acting as a mirror, then I have some questions about an unrelated set of experiments I read about some time ago.  A group of researchers apparently made some kind of microwave mirror out of an "electrical short circuit", that they were able to vibrate over a nano-meter at 0.25c.  Doing so coaxed virtual photons into becoming actual photons, through some theorized property of the Casimir effect.  I do not fully understand what they mean by the vague term in quotes, but it seems curious regardless.


Given that the vibrations they reported are 0.25c, does this mean the surface of their microwave mirror is not a physical surface but rather some kind of field?

If the surface of their microwave mirror is not a physical surface, would it be possible to create a non-physical microwave mirror surface in an emdrive, and if so, would there be any worthwhile benefits to doing so such as greater control of resonance, a more flexible/dynamic shape, mitigation of thermal deformation, ruling out potential error sources, etc?

In either case, if an emdrive's current copper frustum is acting as a microwave mirror, is it possible that resonance is somehow creating a similar nano-scale vibration at relativistic speeds, coaxing virtual particles into becoming real particles?  If so, what would be the implications for thrust signals?

I am a software developer and not a scientist or engineer, so I am fully aware that these questions are likely quite misguided.  Still, I can only contain my curiosity for so long, and I figure there's little harm in wondering aloud once in a while.  Thank you for all the great reading over the months.
Welcome to the forum. :) 
You got good questions so far.  ???
Are you able to refind the paper you are talking about?  If yes please post a link!! Sounds interesting.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DanP on 10/02/2015 06:34 PM
I have not read any actual papers about it, just a series of articles reporting on it.

You can find a lot of links here:
https://www.google.com/search?q=mirror+virtual+photon+to+actual+photon (https://www.google.com/search?q=mirror+virtual+photon+to+actual+photon)

This is one of the links I found most useful, personally:
http://phys.org/news/2011-11-scientists-vacuum.html (http://phys.org/news/2011-11-scientists-vacuum.html)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Stormbringer on 10/02/2015 06:44 PM
Putting this here in case Dr White is correct:

http://phys.org/news/2015-10-team-sampled-electric-field-vacuum-fluctuations.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 10/02/2015 06:46 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432191#msg1432191">Quote from: DanP on 10/02/2015 06:34 PM</a>
I have not read any actual papers about it, just a series of articles reporting on it.

You can find a lot of links here:
https://www.google.com/search?q=mirror+virtual+photon+to+actual+photon (https://www.google.com/search?q=mirror+virtual+photon+to+actual+photon)
May be you mean this? http://arxiv.org/abs/1105.4714
Have to read by myself

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DanP on 10/02/2015 06:50 PM
That seems consistent with what I read, yes.  :-)
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: lmbfan on 10/02/2015 06:57 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432160#msg1432160">Quote from: SteveD on 10/02/2015 04:30 PM</a>
For light, one hertz is one plank constant.

I am not a physicist, but are you sure that 1 cycle per second (1 hertz) is one Planck unit of energy?  My google-fu may be failing me, but I can't find a lower limit to frequency other than possibly the physical size of the universe (an upper limit appears to be related to energy density and black holes).

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 10/02/2015 07:12 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432199#msg1432199">Quote from: DanP on 10/02/2015 06:50 PM</a>
That seems consistent with what I read, yes.  :-)
OK i am reading the paper...
and i find the following:
"If we consider the literal experiment of moving a physical mirror near the speed light,
we quickly see that this experiment is not feasible. Braggio et al. considered[6] the case of moving a typical microwave mirror in an oscillating motion at a frequency of 2 GHz with a displacement of 1 nm. This produces a velocity ratio of only
v/c~10^-7 with an expected photon production rate of approximately 1 per day.
Nevertheless, it requires an input of mechanical power of 100 MW while, at the same time, the system would need to be cooled to ~20 mK to ensure that the EM feld is in its vacuum state...."

The actual experiments (also in vacuum) work at room(ambient radiation) temperature.
Nevertheless its a very interesting paper!

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: DanP on 10/02/2015 07:20 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432207#msg1432207">Quote from: X_RaY on 10/02/2015 07:12 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432199#msg1432199">Quote from: DanP on 10/02/2015 06:50 PM</a>
That seems consistent with what I read, yes.  :-)
OK i am reading the paper...
and i find the following:
"If we consider the literal experiment of moving a physical mirror near the speed light,
we quickly see that this experiment is not feasible. Braggio et al. considered[6] the case of moving a typical microwave mirror in an oscillating motion at a frequency of 2 GHz with a displacement of 1 nm. This produces a velocity ratio of only
v/c~10^-7 with an expected photon production rate of approximately 1 per day.
Nevertheless, it requires an input of mechanical power of 100 MW while, at the same time, the system would need to be cooled to ~20 mK to ensure that the EM feld is in its vacuum state...."

The actual experiments (also in vacuum) work at room temperature.
Nevertheless its a very interesting paper!

I believe in that particular quote, they are discussing movement of a physical mirror and how it would be a bad idea because you'd have to use 100 MW, cool the heck out of it, and still get abysmal results.  They did something different, by somehow oscillating the electrical distance instead of physically moving something, meaning the massive energy requirements are not applicable, and perhaps the cooling also would not be?

Anyway, I will not pretend to understand it.  I am just curious about whether or not similar forces are either already at work in an emdrive, and/or whether similar mechanisms could be applied to the emdrive for a net benefit of some kind.

They seem to be using a lot of terms reminiscent of various theories of emdrive operation.  Virtual quantum vacuum this-and-that, radiation pressure, etc.  This may just be my feeble attempt to find a connection where none exists.  :-)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 07:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432151#msg1432151">Quote from: R.W. Keyes on 10/02/2015 03:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432091#msg1432091">Quote from: SeeShells on 10/02/2015 11:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431883#msg1431883">Quote from: R.W. Keyes on 10/01/2015 10:57 PM</a>
Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.

What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
From DYIer perspective.

The Thermal Expansion Coefficient for copper is: 0.000017 (m/moC)
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thexp.html#c1

This TEC becomes a issue in the changing of the cavity length but also the warping of the hot zones within the copper at the modes points. If we were smarter we could build it of quartz (flashed with silver and gold) which is 28x less or some other 0o TEC material, but that becomes something expensive a DYier can't do.

So a DYier can do a couple things, go low power which is tough to get any readings or go higher power and try to negate by design the issue of TEC. I think the best of both worlds would be negating the TEC thru design (I've tried to do) ... and make it superconducting but I'm going for up to 2 KW into the frustum.

Right now I'm shooting for design control of the TEC and producing a clean RF through a modified magnetron inverter and removing the hot magnetron away from the frustum and feeding the RF into the frustum via antenna or waveguide. These designs have given a very high Q but it is to be seen if I can keep the higher Qs in a real world operation.

Simple thought, lower Qs mean the incoming RF signal is absorbed into the frustum and turned into simply generating heat. Unless I want to drive this with a megawatt(s) klystron turning the frustum into a white hot effervescent accelerating stream of gas, that might give me acceleration but it's outside of the box and a simple rocket then.

MgB2 electroplated onto SiC would be pretty stable at low cryogenic temp, though. Still not easy to do. Magnetrons have messy spectrum but you can clean them up with a PLL.

It seems to me that a high-Q cavity is necessary for high power, otherwise there's going to be a lot of heat, possibly leading to mechanical failure/explosion. But unless that match is good, Q will be horribly high, leading to heat, and in the case of a superconductor, thermal runaway to disaster. So, a good design might have signal generator of adjustable power and frequency (but a good, clean sine wave), and the cavity be superconducting high-Q but have a tunable Q. At startup, power is low and Q is low. the frequency of the signal generator is tuned to the middle of resonance, then the Q is increased and power increased, and the cycle repeated until emdrive effect is strong.

This requires that the adjustment of the Q is stable, and that it be protected against thermal runaway.

If some of the about language/thought seems unclear, please excuse me, I haven't yet had my coffee

"It seems to me that a high-Q cavity is necessary for high power, otherwise there's going to be a lot of heat, possibly leading to mechanical failure/explosion. "

Yes, that's what I said.

There are three ways one can assure the maintenance of a high Q system and this is true for room temperature drives and superconducting.

First, build it out of a nearly 0 degee TEC material. There are plenty of them to choose from. All are expensive and not easy to make but they can be done.

Second. As the frustum heats up and deforms changing the resonate window, shift the incoming frequency to center it again. It will still heat up and deform the frustum in the growth of the side walls and in the deformation of heated zones when generated modes are made. It is unavoidable. 

Third. Knowing the frustum is going to heat up and thermally expand regardless of where you shift the incoming frequency to match. The frustum assures in it's operation that the wave formed modes will collapse and or the different modes will interact with each other. That interaction and or collapse when it happens in a destructive way creates heat. It is in it's design nature to heat up. Design for the thermal expansion.

What I've done in this design is realize that the frustum will continue to heat as long as RF is pumped into the chamber, even when the incoming signal is phased locked to Q.

I capture the two end plates with a quartz rod between running through the center. Quartz is virtually transparent to microwaves and has a very low TEC for growth. (see pic) The large plate is secured to the sidewall with the quartz rod freely running through it and attaches to the small endplate which the tuning micrometer can change the resonate length by sliding the small plate in and out of the tubular tuning chamber at the top. (see pic).

The frustum is going to heat up, the sidewalls are going to expand and the endplates are going to want to deform from mode generation. Capture the endplates setting the resonance distance and secure the copper endplates onto a ceramic plate keeping them from warping. The copper side wall can slide past the small endplate that has a sliding gasket of beryllium copper. Let it expand as its nature to do so but keep the resonance distance between the plates within the magnetron's RF envelope. This can be used at a future date along with a RF locked Q and do it at room temperature.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 10/02/2015 07:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432215#msg1432215">Quote from: SeeShells on 10/02/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432151#msg1432151">Quote from: R.W. Keyes on 10/02/2015 03:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432091#msg1432091">Quote from: SeeShells on 10/02/2015 11:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431883#msg1431883">Quote from: R.W. Keyes on 10/01/2015 10:57 PM</a>
Hi everyone, I've been away for a while, and I have tried to catch up but there's just so much to read.

What is that general opinion about a high Q being necessary for the emdrive to work efficiently? I haven't seen much about going to the extremes of high-Q, such as superconducting cavities at cryogenic temperatures. I understand that such a cool temperature makes test conditions more difficult, but if high Q will result in greater efficiency, isn't this worth trying? Also, magnesium diboride shouldn't be too hard to form (type II, cuprate superconductors might be quite a bit more of a chore). One thing, though, that concerns me: with such a high Q, the bandwidth would be very narrow, and that unless the microwave source is extremely well matched to the cavity's resonance, it will require tuning. From my experience with tuning high-Q antennas in amateur radio, I know that it is possible to just slide right past the point of resonance if tuning is too coarse. One solution to the problem might be to temporarily drop the Q, just so it's easier to find the proper range, and then gradually tighten it in fine tuning. Though I have a hunch that the highest-Q, available from superconducting cavities, might create such a shape bandwidth that none of our signal sources are going to be precise and stable enough to stay tuned to it, so we might have to always artificially drop the Q from what a superconducting cavity might be capable of. I haven't put this to the test, nor have I even done any numerical reasoning on the idea, but I think it's worth mentioning.
From DYIer perspective.

The Thermal Expansion Coefficient for copper is: 0.000017 (m/moC)
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thexp.html#c1

This TEC becomes a issue in the changing of the cavity length but also the warping of the hot zones within the copper at the modes points. If we were smarter we could build it of quartz (flashed with silver and gold) which is 28x less or some other 0o TEC material, but that becomes something expensive a DYier can't do.

So a DYier can do a couple things, go low power which is tough to get any readings or go higher power and try to negate by design the issue of TEC. I think the best of both worlds would be negating the TEC thru design (I've tried to do) ... and make it superconducting but I'm going for up to 2 KW into the frustum.

Right now I'm shooting for design control of the TEC and producing a clean RF through a modified magnetron inverter and removing the hot magnetron away from the frustum and feeding the RF into the frustum via antenna or waveguide. These designs have given a very high Q but it is to be seen if I can keep the higher Qs in a real world operation.

Simple thought, lower Qs mean the incoming RF signal is absorbed into the frustum and turned into simply generating heat. Unless I want to drive this with a megawatt(s) klystron turning the frustum into a white hot effervescent accelerating stream of gas, that might give me acceleration but it's outside of the box and a simple rocket then.

MgB2 electroplated onto SiC would be pretty stable at low cryogenic temp, though. Still not easy to do. Magnetrons have messy spectrum but you can clean them up with a PLL.

It seems to me that a high-Q cavity is necessary for high power, otherwise there's going to be a lot of heat, possibly leading to mechanical failure/explosion. But unless that match is good, Q will be horribly high, leading to heat, and in the case of a superconductor, thermal runaway to disaster. So, a good design might have signal generator of adjustable power and frequency (but a good, clean sine wave), and the cavity be superconducting high-Q but have a tunable Q. At startup, power is low and Q is low. the frequency of the signal generator is tuned to the middle of resonance, then the Q is increased and power increased, and the cycle repeated until emdrive effect is strong.

This requires that the adjustment of the Q is stable, and that it be protected against thermal runaway.

If some of the about language/thought seems unclear, please excuse me, I haven't yet had my coffee

"It seems to me that a high-Q cavity is necessary for high power, otherwise there's going to be a lot of heat, possibly leading to mechanical failure/explosion. "

Yes, that's what I said.

There are three ways one can assure the maintenance of a high Q system and this is true for room temperature drives and superconducting.

First, build it out of a nearly 0 degee TEC material. There are plenty of them to choose from. All are expensive and not easy to make but they can be done.

Second. As the frustum heats up and deforms changing the resonate window, shift the incoming frequency to center it again. It will still heat up and deform the frustum in the growth of the side walls and in the deformation of heated zones when generated modes are made. It is unavoidable. 

Third. Knowing the frustum is going to heat up and thermally expand regardless of where you shift the incoming frequency to match. The frustum assures in it's operation that the wave formed modes will collapse and or the different modes will interact with each other. That interaction and or collapse when it happens in a destructive way creates heat. It is in it's design nature to heat up. Design for the thermal expansion.

What I've done in this design is realize that the frustum will continue to heat as long as RF is pumped into the chamber, even when the incoming signal is phased locked to Q.

I capture the two end plates with a quartz rod between running through the center. Quartz is virtually transparent to microwaves and has a very low TEC for growth. (see pic) The large plate is secured to the sidewall with the quartz rod freely running through it and attaches to the small endplate which the tuning micrometer can change the resonate length by sliding the small plate in and out of the tubular tuning chamber at the top. (see pic).

The frustum is going to heat up, the sidewalls are going to expand and the endplates are going to want to deform from mode generation. Capture the endplates setting the resonance distance and secure the copper endplates onto a ceramic plate keeping them from warping. The copper side wall can slide past the small endplate that has a sliding gasket of beryllium copper. Let it expand as its nature to do so but keep the resonance distance between the plates within the magnetron's RF envelope. This can be used at a future date along with a RF locked Q and do it at room temperature.

Shell
Heat caused by the MW energy is everywhere in such high power experiments, the question is where it is:
@ low Q the power will be reflected and heats the magnetron/source
@ matched resonance frequency/impedance it will heat the frustum
point ::)
But i think your tunable design is great for this experiments, also the modified loop antenna(PS: my favorite design for the TE01p mode! You know with kind of antenna i think about ;) :) )

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 08:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432220#msg1432220">Quote from: X_RaY on 10/02/2015 07:50 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432215#msg1432215">Quote from: SeeShells on 10/02/2015 07:35 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432151#msg1432151">Quote from: R.W. Keyes on 10/02/2015 03:57 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432091#msg1432091">Quote from: SeeShells on 10/02/2015 11:38 AM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1431883#msg1431883">Quote from: R.W. Keyes on 10/01/2015 10:57 PM</a>
Heat caused by the MW energy is everywhere in such high power experiments, the question is where it is:
@ low Q the power will be reflected and heats the magnetron/source
@ matched resonance frequency it will heat the frustum
point ::)
But i think your tunable design is great for this experiments, also the modified loop antenna(my favorite design for the TE01p mode)! You know with kind of antenna think about ;) :)
I'm killing 2 birds with one stone. (old saying) I'm building a dual waveguide injector system and the same frustum will allow the antennas in the small end plate.
Simulations in meep have shown a high Q an extraordinary beautiful waveform action with the dual waveguide injection. Because of this I'm doing both in one frustum. Taking a little more time but utterly worth it.

Dual injectors... see meep animation attached.

Shell

PS: It will be a modified horseshoe shaped loop U ,  like a u-turn dipole but not a full circle.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: glennfish on 10/02/2015 08:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432227#msg1432227">Quote from: SeeShells on 10/02/2015 08:16 PM</a>

Dual injectors... see meep animation attached.

Shell

Dumb questions as a data miner:
1.  Does that animated gif show a field propogation from one end to the other?
2.  If so, is there a thermal gradient that follows that propogation?
3.  If so, on the outside of the wall, would there be a comparable thermal gradient that also propogates?

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: A_M_Swallow on 10/02/2015 08:39 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432160#msg1432160">Quote from: SteveD on 10/02/2015 04:30 PM</a>
{snip}
Here's the problem, I said that each bounce wants to redshift the light by "about" so many hertz.  For light, one hertz is one plank constant.  The plank constant is the smallest possible unit of energy in the Universe.  It has to be an integer.
{snip}

It may have to be in an integer but Planks's constant has not been given the value 1 but 6.626070040(81)×10−34 J.s

You have to change the physical sizes to multiples of Plank's constant and also change the time units. This means 1 second is not a single digit integer but a 34 digit number in the new units. The same applies to the 8Hz.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/02/2015 08:55 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432236#msg1432236">Quote from: glennfish on 10/02/2015 08:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432227#msg1432227">Quote from: SeeShells on 10/02/2015 08:16 PM</a>

Dual injectors... see meep animation attached.

Shell

Dumb questions as a data miner:
1.  Does that animated gif show a field propogation from one end to the other?
2.  If so, is there a thermal gradient that follows that propogation?
3.  If so, on the outside of the wall, would there be a comparable thermal gradient that also propogates?
It would appear it does propagate to the small end. As far as the thermal gradient I would assume it would follow the highest energy modes. Don't forget that what you're seeing here is happening only during one cycle of 2.47 billion in one second. The copper will not thermally conduct patterns looking like this at those speeds.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/03/2015 12:00 AM
http://www.sciencedaily.com/releases/2014/07/140722091425.htm
Theorists propose way to amplify force of vacuum fluctuations

Interesting also.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: aero on 10/03/2015 01:10 AM
Shell:

Thinking about your sliding end plate and the effect of uneven heating. Since expansion of copper is linear with change in temperature, if both the small end circumference of the frustum and the diameter of the small end plate are heated equally, the relative change in the diameters will be the same. Unfortunately, if the end plate heats more than the small end circumference of the frustum, won't the end plate diameter expand then bind rather than move?

I know you're thorough and so must have considered this.

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/03/2015 02:58 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432295#msg1432295">Quote from: aero on 10/03/2015 01:10 AM</a>
Shell:

Thinking about your sliding end plate and the effect of uneven heating. Since expansion of copper is linear with change in temperature, if both the small end circumference of the frustum and the diameter of the small end plate are heated equally, the relative change in the diameters will be the same. Unfortunately, if the end plate heats more than the small end circumference of the frustum, won't the end plate diameter expand then bind rather than move?

I know you're thorough and so must have considered this.

aero
This is why I bonded the copper sheet onto the Ceramic plates, ceramic is relatively unaffected by the thermal expansion. The bottom plate is locked on to the sidewalls of the frustum and the top plate is secured to the quartz rod and from the side of the small plate to the side of the top tune chamber is a flexible beryllium gasket that allows it to slide freely for tuning and also the copper walls of the frustum to slide past it as they expand.


Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 10/03/2015 01:49 PM
For the diy's
Found this paper
Please have a look for interest sake, and I would make the same recommendations stated.
the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful  as well

I'm of the thought, that targeting "thermal air eddy elimination"  will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise  component for easier isolation and removal. I like the quote earlier on a few pages back
"A surrogate to noise is the standard deviation or variance."
so its logical to minimise it.

Schlieren Optics is tell us its there... but that we just cannot see it yet...  [thermal air eddies and noise]
much like turbulence you experience in an air plane

One other thermal  management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy  air flow that's why you find slots in more common use on computers.
and yet another promotes what is called 'pin finning' instead of normal  finning on Electronic chips

https://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systems
and how about fin orientation vertical vs horizontal?

another one of those things  to ponder about

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/03/2015 03:38 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432414#msg1432414">Quote from: Silversheep2011 on 10/03/2015 01:49 PM</a>
For the diy's
Found this paper
Please have a look for interest sake, and I would make the same recommendations stated.
the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful  as well

I'm of the thought, that targeting "thermal air eddy elimination"  will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise  component for easier isolation and removal. I like the quote earlier on a few pages back
"A surrogate to noise is the standard deviation or variance."
so its logical to minimise it.

Schlieren Optics is tell us its there... but that we just cannot see it yet...  [thermal air eddies and noise]
much like turbulence you experience in an air plane

One other thermal  management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy  air flow that's why you find slots in more common use on computers.
and yet another promotes what is called 'pin finning' instead of normal  finning on Electronic chips

https://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systems
and how about fin orientation vertical vs horizontal?

another one of those things  to ponder about
Nice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/03/2015 04:52 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432439#msg1432439">Quote from: rfmwguy on 10/03/2015 03:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432414#msg1432414">Quote from: Silversheep2011 on 10/03/2015 01:49 PM</a>
For the diy's
Found this paper
Please have a look for interest sake, and I would make the same recommendations stated.
the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful  as well

I'm of the thought, that targeting "thermal air eddy elimination"  will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise  component for easier isolation and removal. I like the quote earlier on a few pages back
"A surrogate to noise is the standard deviation or variance."
so its logical to minimise it.

Schlieren Optics is tell us its there... but that we just cannot see it yet...  [thermal air eddies and noise]
much like turbulence you experience in an air plane

One other thermal  management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy  air flow that's why you find slots in more common use on computers.
and yet another promotes what is called 'pin finning' instead of normal  finning on Electronic chips

https://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systems
and how about fin orientation vertical vs horizontal?

another one of those things  to ponder about
Nice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.

Hook up those dual muffin fans like I suggested, if you wouldn't mind, blowing horizontally off from the top.
Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 10/03/2015 11:04 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432462#msg1432462">Quote from: SeeShells on 10/03/2015 04:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432439#msg1432439">Quote from: rfmwguy on 10/03/2015 03:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432414#msg1432414">Quote from: Silversheep2011 on 10/03/2015 01:49 PM</a>
For the diy's
Found this paper
Please have a look for interest sake, and I would make the same recommendations stated.
the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful  as well

I'm of the thought, that targeting "thermal air eddy elimination"  will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise  component for easier isolation and removal. I like the quote earlier on a few pages back
"A surrogate to noise is the standard deviation or variance."
so its logical to minimise it.

Schlieren Optics is tell us its there... but that we just cannot see it yet...  [thermal air eddies and noise]
much like turbulence you experience in an air plane

One other thermal  management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy  air flow that's why you find slots in more common use on computers.
and yet another promotes what is called 'pin finning' instead of normal  finning on Electronic chips

https://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systems
and how about fin orientation vertical vs horizontal?

another one of those things  to ponder about
Nice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.

Hook up those dual muffin fans like I suggested, if you wouldn't mind, blowing horizontally off from the top.
Shell

I'm glad to see its of interest to both  seashells and rfmguy
 but  I can see possible trouble with that arrangement shells...

while I'm enjoying morning coffee, and looking over sketch's it appears there is the makings of an airplane wing here the same effect as blowing over top of a sheet of paper - could be mild lift but I'm sure its there.
So up for some ideas?
1. start by allowing some air space "under" the magnetron so that it disconnects it from the top plate sheet surface perhaps use some adjustable spacer legs
2. consider using  he balance beam to find a counter lift angle could be found by adding a few degrees say it works out at 1°-2° of  down rake via the adjustable legs  to counter  balance out any lifting force being  generated by the cooling fans. looks like it could be a very much likely to be trial and error  approach for a while.
I do give credit though, blowing through sideways seems to be the best mounting direction for fans compared to top and bottom mounting fans.

there is another aspect to think about on this issue: all the heat has go 'somewhere' and that  'somewhere' has to be dissipated heat into air, there is simply no other path.

- its going to mean a lot of hot air going up, and a lot of cold air going down.-

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/03/2015 11:35 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432531#msg1432531">Quote from: Silversheep2011 on 10/03/2015 11:04 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432462#msg1432462">Quote from: SeeShells on 10/03/2015 04:52 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432439#msg1432439">Quote from: rfmwguy on 10/03/2015 03:38 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432414#msg1432414">Quote from: Silversheep2011 on 10/03/2015 01:49 PM</a>
For the diy's
Found this paper
Please have a look for interest sake, and I would make the same recommendations stated.
the need to place 'a gap at the bottom' of a rack to the first electronic amplifier component for increasing the free air movement and whether we could do the samething could apply to test setups involving magnetrons. There are also some do's and don't do that could be useful  as well

I'm of the thought, that targeting "thermal air eddy elimination"  will bring everybody a better and more accurate results in that desire to isolating out the direct EM Drive effect by removing or at least minimising and/or linearizing the thermal noise  component for easier isolation and removal. I like the quote earlier on a few pages back
"A surrogate to noise is the standard deviation or variance."
so its logical to minimise it.

Schlieren Optics is tell us its there... but that we just cannot see it yet...  [thermal air eddies and noise]
much like turbulence you experience in an air plane

One other thermal  management reference's pointed to using rectangular slotted holes as being better than round holes for purposes of easy  air flow that's why you find slots in more common use on computers.
and yet another promotes what is called 'pin finning' instead of normal  finning on Electronic chips

https://en.wikipedia.org/wiki/Thermal_management_of_electronic_devices_and_systems
and how about fin orientation vertical vs horizontal?

another one of those things  to ponder about
Nice info! I have decided to construct a home-built Schlieren Optic system over the next several weeks to analyze the NSF-1701 assembly, under power and not on the balance beam. I will video this.

Hook up those dual muffin fans like I suggested, if you wouldn't mind, blowing horizontally off from the top.
Shell

I'm glad to see its of interest to both  seashells and rfmguy
 but  I can see possible trouble with that arrangement shells...

while I'm enjoying morning coffee, and looking over sketch's it appears there is the makings of an airplane wing here the same effect as blowing over top of a sheet of paper - could be mild lift but I'm sure its there.
So up for some ideas?
1. start by allowing some air space "under" the magnetron so that it disconnects it from the top plate sheet surface perhaps use some adjustable spacer legs
2. consider using  he balance beam to find a counter lift angle could be found by adding a few degrees say it works out at 1°-2° of  down rake via the adjustable legs  to counter  balance out any lifting force being  generated by the cooling fans. looks like it could be a very much likely to be trial and error  approach for a while.
I do give credit though, blowing through sideways seems to be the best mounting direction for fans compared to top and bottom mounting fans.

there is another aspect to think about on this issue: all the heat has go 'somewhere' and that  'somewhere' has to be dissipated heat into air, there is simply no other path.

- its going to mean a lot of hot air going up, and a lot of cold air going down.-

The magnetron is rfmwguy's main issue with hot air eddies rising vertically up from the frustum. this creates a low pressure directly above the frustum and the air below the frustum gets pulled along the sidewalls to fill the void. Chaotic actions occur because of the pressure differentials between bottom and top.

By blowing the thermal heated air to the side it can be allowed to rise without adding a chaotic component to the frustum.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Silversheep2011 on 10/04/2015 01:27 AM
Quote:"The magnetron is rfmwguy's main issue with hot air eddies rising vertically up from the frustum. this creates a low pressure directly above the frustum and the air below the frustum gets pulled along the sidewalls to fill the void. Chaotic actions occur because of the pressure differentials between bottom and top.

By blowing the thermal heated air to the side it can be allowed to rise without adding a chaotic component to the frustum."


Seashells, Agree with comment- and on further thinking about it.  Wouldn't  it make sense to test  with the magnetron Off, and the cooling fans On first in the actual beam configuration as part of a  mock up in a calibrating pre-run? and  see what the numbers say?
if there was no noticeable movement up or down, or oscillations, with fans On only operation
you would have to say only then that's its onto a "good thing" to do as a standard part off the setup on EMD runs  [run cooling air sideways to magnetron with cooling fans],   if correct. And if not, well it means looking  for other alternatives or ways to mitigate those  thermal and air movement effects?
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/04/2015 01:57 AM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432549#msg1432549">Quote from: Silversheep2011 on 10/04/2015 01:27 AM</a>
Quote:"The magnetron is rfmwguy's main issue with hot air eddies rising vertically up from the frustum. this creates a low pressure directly above the frustum and the air below the frustum gets pulled along the sidewalls to fill the void. Chaotic actions occur because of the pressure differentials between bottom and top.

By blowing the thermal heated air to the side it can be allowed to rise without adding a chaotic component to the frustum."


Seashells, Agree with comment- and on further thinking about it.  Wouldn't  it make sense to test  with the magnetron Off, and the cooling fans On first in the actual beam configuration as part of a  mock up in a calibrating pre-run? and  see what the numbers say?
if there was no noticeable movement up or down, or oscillations, with fans On only operation
you would have to say only then that's its onto a "good thing" to do as a standard part off the setup on EMD runs  [run cooling air sideways to magnetron with cooling fans],   if correct. And if not, well it means looking  for other alternatives or ways to mitigate those  thermal and air movement effects?

Absolutely! You need a baseline test without the magnetron to characterize the effects of the fans. Then do your powered test and since you have the non-fan powered tests you would have simply more data to digest and hopefully the heat making the vertical chaotic component would be greatly negated by horizontally diverting it to the outside of the frustum. You should get clearer data.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cl33250 on 10/04/2015 06:19 AM
Please don't waste time increasing airflow across the magnetron.  Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/04/2015 02:26 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432584#msg1432584">Quote from: cl33250 on 10/04/2015 06:19 AM</a>
Please don't waste time increasing airflow across the magnetron.  Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.
Thank you for your post. This is an open discussion and any thoughts on this are very welcome.

So what you're saying is the the hot vertical air rising from the magnetron cannot be diverted to the sides of the frustum changing chaotic air movements from a vertical component to a horizontal one that doesn't effect the vertical measurements as much? The will effect the vertical measurements now be more then just letting it rise as a convection current?

I also think there might be another factor, because the top of rfmwguy's frustum has sides and could also be trapping hot air generated from the frustum.
https://www.youtube.com/watch?v=Dd-xTvxb0LU

Shell

Edit: speeling

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/04/2015 03:22 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432584#msg1432584">Quote from: cl33250 on 10/04/2015 06:19 AM</a>
Please don't waste time increasing airflow across the magnetron.  Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.
I would agree the horizontal fans may increase the chimney effect and create unwanted horizontal oscillations. Thermal plumes can only be controlled by ambient air temp equaling device temp...or vacuum testing.

This thought experiment has kept me up at nights...finally thought it best to not add anything and characterize lift, using dsoftware to "extract" displacement changes during mag ON state. Following an ON state, the lift rises a a fairly predictanbe rate with some minor variations as the heat plumes exit the frustum somewhat uniformly.

However, am curious enough to use Schleiren photography to see this for myself. Though my test stand is temporarily disassembled, can do a static power test and shoot some video later this year...if I get some donation help. The proper mirrors and light sources are not cheap.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: cl33250 on 10/04/2015 03:47 PM
In reply to shell:  Assymetric horizontal airflow creates lift.  Since the magnetron is not a symmetric airfoil, it will have chaotic, turbulent airflow around it at best.  Characterizing the resulting forces accurately enough to discern an underlying mN signal under it would be difficult.

Considering that, work to streamline the magnetron may help regulate the lift and drag from the convection currents. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/04/2015 04:10 PM
Disappointed to notice wallofwolfstreet has left the building here and on reddit apparently. Anyone have the details on this? I enjoyed his posts, even tho he was not a firm believer...
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/04/2015 04:58 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432637#msg1432637">Quote from: cl33250 on 10/04/2015 03:47 PM</a>
In reply to shell:  Assymetric horizontal airflow creates lift.  Since the magnetron is not a symmetric airfoil, it will have chaotic, turbulent airflow around it at best.  Characterizing the resulting forces accurately enough to discern an underlying mN signal under it would be difficult.

Considering that, work to streamline the magnetron may help regulate the lift and drag from the convection currents.

Thanks, that helps me understand.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 10/04/2015 05:36 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432634#msg1432634">Quote from: rfmwguy on 10/04/2015 03:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432584#msg1432584">Quote from: cl33250 on 10/04/2015 06:19 AM</a>
Please don't waste time increasing airflow across the magnetron.  Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.
I would agree the horizontal fans may increase the chimney effect and create unwanted horizontal oscillations. Thermal plumes can only be controlled by ambient air temp equaling device temp...or vacuum testing.

This thought experiment has kept me up at nights...finally thought it best to not add anything and characterize lift, using dsoftware to "extract" displacement changes during mag ON state. Following an ON state, the lift rises a a fairly predictanbe rate with some minor variations as the heat plumes exit the frustum somewhat uniformly.

However, am curious enough to use Schleiren photography to see this for myself. Though my test stand is temporarily disassembled, can do a static power test and shoot some video later this year...if I get some donation help. The proper mirrors and light sources are not cheap.

I've been thinking about this quite a bit as well.   I agree that the use of active (fan) cooling is likely to introduce very chaotic flow and -at the level of signal we are looking for here - more noise than they eliminate.

Vacuum is one way of course - likely the best and as is typically for the best - the most expensive route.   One of the reasons I am strongly considering a rotary stage setup for my DIY configuration is that then the force vector being measured will be perpendicular to thermal effects (if designed carefully). 

Another approach which we touched on a few pages back was the second cavity arranged in such a way as to cancel (or nearly so ) thermal effects while adding "emdrive" effects.   While I was advocating the need for making the cavities as near identical as possible - in reality I was wrong and as was pointed out that really isn't necessary - just getting "close" will improve the S/N.   

Just random thoughts on a Sunday afternoon.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: graybeardsyseng on 10/04/2015 05:54 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432641#msg1432641">Quote from: rfmwguy on 10/04/2015 04:10 PM</a>
Disappointed to notice wallofwolfstreet has left the building here and on reddit apparently. Anyone have the details on this? I enjoyed his posts, even tho he was not a firm believer...

I have also been noticing a drop in post count here and reddit too - particularly from some of the more prolific contributors.   If I were a conspiracy oriented person - which I am not - I would wonder if it has anything to do with the recent reports with  more and better quality data saying SOMETHING is happening that needs looked at.

  Surely if the data were unequivocally indicating "nothing to see here, move along, we've all been wasting our time" some previous purveyors of preserving the status quo would be shouting that from the rooftops but instead I find myself hearing crickets from them. 

But likewise some of those who were either supportive of the concept or at least supportive of impartially investigation and welcoming of data of all sorts seemed to have dropped of in volume and scope of their posts, not everyone by any means - but some real luminaries none the less.

If it were August I would suspect that lots of folks were just taking a late summer vacation or if September I would suspect many are just getting down to the new semester at their institutions.   

If this was a Hollywood conspiracy theory movie I would be suspecting the hero was going to find these missing voices were part of a vast group of commercial/government/academic investigators who had found something really significant and had been told to be quiet. And of course he/she would have to expose them and the secret and get the girl/boy and live happy ever after (perhaps on Pluto heh heh).

But of course that's just crazy talk - so I suspect they have all been off waiting in line to see "The Martian" in 3D.   (planning to myself RSN). 

Just some weirder thoughts on a Sunday afternoon - after an adult beverage or two.

Herman

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: SeeShells on 10/04/2015 05:56 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432666#msg1432666">Quote from: graybeardsyseng on 10/04/2015 05:36 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432634#msg1432634">Quote from: rfmwguy on 10/04/2015 03:22 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432584#msg1432584">Quote from: cl33250 on 10/04/2015 06:19 AM</a>
Please don't waste time increasing airflow across the magnetron.  Pressure/lift is related to velocity squared, and the fans blowing any air around the magnetron will create chaotic air currents with orders of magnitude more force than relatively slow thermal air currents.
I would agree the horizontal fans may increase the chimney effect and create unwanted horizontal oscillations. Thermal plumes can only be controlled by ambient air temp equaling device temp...or vacuum testing.

This thought experiment has kept me up at nights...finally thought it best to not add anything and characterize lift, using dsoftware to "extract" displacement changes during mag ON state. Following an ON state, the lift rises a a fairly predictanbe rate with some minor variations as the heat plumes exit the frustum somewhat uniformly.

However, am curious enough to use Schleiren photography to see this for myself. Though my test stand is temporarily disassembled, can do a static power test and shoot some video later this year...if I get some donation help. The proper mirrors and light sources are not cheap.

I've been thinking about this quite a bit as well.   I agree that the use of active (fan) cooling is likely to introduce very chaotic flow and -at the level of signal we are looking for here - more noise than they eliminate.

Vacuum is one way of course - likely the best and as is typically for the best - the most expensive route.   One of the reasons I am strongly considering a rotary stage setup for my DIY configuration is that then the force vector being measured will be perpendicular to thermal effects (if designed carefully). 

Another approach which we touched on a few pages back was the second cavity arranged in such a way as to cancel (or nearly so ) thermal effects while adding "emdrive" effects.   While I was advocating the need for making the cavities as near identical as possible - in reality I was wrong and as was pointed out that really isn't necessary - just getting "close" will improve the S/N.   

Just random thoughts on a Sunday afternoon.

You know another effect you could see is when you turn one 180 from the other and run.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: rfmwguy on 10/04/2015 06:06 PM
NSF-1701 Paper Update. With thanks to many, I am releasing my paper a day early. I look forward to your commentary.

All the best,
Dave
Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: jstepp590 on 10/04/2015 07:50 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432674#msg1432674">Quote from: rfmwguy on 10/04/2015 06:06 PM</a>
NSF-1701 Paper Update. With thanks to many, I am releasing my paper a day early. I look forward to your commentary.

All the best,
Dave

Long time lurker here. I have been following the forum avidly for months, and I have donated to Shells experimental setup. I am so far out of my depth it is ridiculous, but I have learned so much and thank you. The reason why I am writing has to do with rfmwguy's funding. I noticed that you posted your results on YouTube and they're great. However, I believe what could help with your next project and also Shells is that, when posting onto YouTube to make a couple of changes.
The first is to list that these are tests of the EmDrive in the title, and also to add advertising like most of the other video posters. The reason to add EmDrive to the title of your YouTube posts is that very few people are going to look for NSF-1701 and Electromagnetic Engine Experiment as they have no idea what that is. People look for keywords and they will be looking for EmDrive so you are probably missing a lot of results and searches. With more search hits you will make more money from advertising, which will help fund your good work. Just what I hope is a helpful suggestion.  :)

Back to lurking...

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: X_RaY on 10/04/2015 08:08 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432674#msg1432674">Quote from: rfmwguy on 10/04/2015 06:06 PM</a>
NSF-1701 Paper Update. With thanks to many, I am releasing my paper a day early. I look forward to your commentary.

All the best,
Dave
Can't agree (or at least I am not sure about) your Q definition is really helpful, I think it leads to some confusion about it, S11 and S12 measurements are well defined IMHO.
Nevertheless congratulations to your revealing test report. I like your professional work.
And i wish you good luck for your next project in 2016! :)

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: tchernik on 10/04/2015 08:16 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432670#msg1432670">Quote from: graybeardsyseng on 10/04/2015 05:54 PM</a>
<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432641#msg1432641">Quote from: rfmwguy on 10/04/2015 04:10 PM</a>
Disappointed to notice wallofwolfstreet has left the building here and on reddit apparently. Anyone have the details on this? I enjoyed his posts, even tho he was not a firm believer...

I have also been noticing a drop in post count here and reddit too - particularly from some of the more prolific contributors.   If I were a conspiracy oriented person - which I am not - I would wonder if it has anything to do with the recent reports with  more and better quality data saying SOMETHING is happening that needs looked at.

  Surely if the data were unequivocally indicating "nothing to see here, move along, we've all been wasting our time" some previous purveyors of preserving the status quo would be shouting that from the rooftops but instead I find myself hearing crickets from them. 

But likewise some of those who were either supportive of the concept or at least supportive of impartially investigation and welcoming of data of all sorts seemed to have dropped of in volume and scope of their posts, not everyone by any means - but some real luminaries none the less.

If it were August I would suspect that lots of folks were just taking a late summer vacation or if September I would suspect many are just getting down to the new semester at their institutions.   

If this was a Hollywood conspiracy theory movie I would be suspecting the hero was going to find these missing voices were part of a vast group of commercial/government/academic investigators who had found something really significant and had been told to be quiet. And of course he/she would have to expose them and the secret and get the girl/boy and live happy ever after (perhaps on Pluto heh heh).

But of course that's just crazy talk - so I suspect they have all been off waiting in line to see "The Martian" in 3D.   (planning to myself RSN). 

Just some weirder thoughts on a Sunday afternoon - after an adult beverage or two.

Herman

I'm really wishing you are right and this is the calm before the storm, and for EagleWorks or some other important lab or agency to come with a big news splasher around the holidays (for making them even better).

But I guess people are simply taking some time for themselves after the frenzy of the latter months. Some may be back if we do get some big news or not, but some others may simply be moving on.

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: wallofwolfstreet on 10/04/2015 08:27 PM

<a href="http://forum.nasaspaceflight.com/index.php?topic=38203.msg1432641#msg1432641">Quote from: rfmwguy on 10/04/2015 04:10 PM</a>
Disappointed to notice wallofwolfstreet has left the building here and on reddit apparently. Anyone have the details on this? I enjoyed his posts, even tho he was not a firm believer...

I appreciate that you feel my posts have been constructive.

I haven't left actually, just have some other things taking up more time.  I deleted my reddit account because whenever I commented on /r/emdrive, I found myself wasting time just looking through random posts on /r/all.  Someone with better impulse control could have saved the account and just posted less, but I went for the burnt bridge option.   

Title: Re: EM Drive Developments - related to space flight applications - Thread 4
Post by: Chris Bergin on 10/04/2015 08:30 PM
And on to thread 5. Over 3,000,000 views on the EM Drive Threads now.

Pick up here:
http://forum.nasaspaceflight.com/index.php?topic=38577.0