Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1797179 times)

Offline SeeShells

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« Last Edit: 08/05/2015 03:21 AM by SeeShells »

Offline zen-in

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{snip}
It has become obvious to me the EM-drive is bogus science.   I don't believe anything Mr. Shawyer claims.   The Eagleworks project just got less and less "thrust".   Yang doesn't want to discuss the research she did.   Maybe the Chinese authorities see a benefit in using it for a misinformation campaign, akin to the USAF UFO hoax of the 50's.   So I don't think it is worth polluting RF spectrum anymore with this pointless activity.


Something is causing this box to move.



It's anyone's guess what is happening there.   There are fans, fluid pumps, kiloWatts of DC power, and hundreds of Watts of RF power.   That video is from 2006, 9 years ago.   Since then no one has independently researched the device to rule out obvious mundane reasons.   Show me a paper by a competent scientist who has been allowed to examine this contraption.   Someone who has been given unfettered access to examine it.   I suspect the engineers at Boeing were given this opportunity after signing an NDA.     History is full of this kind of stuff.   Do a Google search for John Ernst Worrell Keely.   Very similar situation except 120 years previous to this hoax.   Or how about Josef Papp?    He made the news in 1966 with the claim of a 300 MPH midget submarine that was built a few miles from where I lived at the time.   I knew people who believed his wild claims.   There are many who claim fantastic discoveries.   These individuals all operated the same way: extravagant claims, tightly controlled demonstrations,  many disenchanted investors, and gobblydygook theory of operation.    The EM-Drive is just a rebranded perpetual motion machine.

http://www.hisutton.com/300mph%20home-build%20Supercavitating%20midget%20submarine.html
« Last Edit: 08/05/2015 02:59 AM by zen-in »

Online WarpTech

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I've stumbled across a bit of difficulty.

Mr. Shawyer's theory paper cites Cullin, p3, Equation 15 indicates that the force from radiation pressure is proportional to guide wavelength.

Jones, p361 Table 1 that the force is in proportion to the phase velocity index of refraction, not the group velocity index.

Q: Is there an obvious reason why dielectric materials would behave differently from waveguides in this regard?

Thanks.

Shawyer's theory Paper
http://www.emdrive.com/theorypaper9-4.pdf

The Measurement of Optical Radiation Pressure in Dispersive Media
R. V. Jones and B. Leslie
Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences
Vol. 360, No. 1702 (Apr. 4, 1978), pp. 347-363
http://www.jstor.org/stable/79586

Absolute Power Measurement at Microwave Frequencies
A.L. Cullen
1951, Journal unknown.
https://dl.dropboxusercontent.com/u/3621645/1951%20Cullen%20Power%20at%20MW%20Frequencies%2011-09-1951.pdf


It isn't different. When you plug in the formula for guide wavelength into Cullen's equation, you get 1/v-phase.
Todd

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Shell, I didn't realize they were both gifs. When I click the big one to enlarge it makes me cross-eyed.
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Offline SeeShells

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Shell, I didn't realize they were both gifs. When I click the big one to enlarge it makes me cross-eyed.
It does tend to make you think of Tie Die T shirts.

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Shell, I didn't realize they were both gifs. When I click the big one to enlarge it makes me cross-eyed.

Looks like random bouncing. I don't really see any standing wave pattern to it. The antenna is offset from the middle? In that configuration, you may need to run the simulation longer to develop a standing wave that has more amplitude than the antenna. Once the Q factor takes over in the cavity, the antenna should be a smaller contribution. Since we are looking at such a short slice, and during the turn-on transient, I think what we see has more to do with the antenna than the cavity resonance, IMO.
Todd

Offline meberbs

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I've stumbled across a bit of difficulty.

Mr. Shawyer's theory paper cites Cullin, p3, Equation 15 indicates that the force from radiation pressure is proportional to guide wavelength.

Jones, p361 Table 1 that the force is in proportion to the phase velocity index of refraction, not the group velocity index.

Q: Is there an obvious reason why dielectric materials would behave differently from waveguides in this regard?

DeltaMass already had a good link that explains that phase velocity is the correct answer. Waveguides are a bit different, so guide wavelength tends to be what equations are written in terms of. I would like to point out that Shawyer's paper is not a good place to go for explanations of the EM drive. There are many places in the paper where his physics is wrong (and sometimes not even wrong).

He tries to use existing theories to explain the thrust, but standard physics calculations when done correctly would yield no thrust. Either new physics is needed to explain it, or (more likely in my opinion) the thrust is some type of experimental artifact (e.g. thermal expansion).

A theory to the EM Drive Thrust

When you shine light or thrust from any of the electromagnetic wavelength the object you are hitting will move in the opposite direction and the force applied will bounce off. But when two wavelenghts of different amplitude collide they cancel each other out

The reason the Em Drive has a net thrust in one direction is because when the electromagnetic wave reaches the wide end there is a greater likelihood of the waves being canceled out, equating in a net thrust at the smaller end.

It would be simpler to just have a copper plate and bounce the wavelenghts off this.

Pieces:
1. Two intersecting waves of the same frequency may add or subtract their total amplitudes, depending on if the waves are in phase or not.  If the Frequencies are not the same, they will combine to create a new "beat frequency" wave that is lower than both.


Your explanation of beat frequency is correct. I will add that the frequency everywhere in the cavity is the same, so the reflections of waves traveling in opposite directions will create a standing wave pattern. I am not sure if that is relevant to Quintaglio's theory, since I don't understand what he is trying to say, especially with statements such as "the force applied will bounce off". My guess for that one is that he means to say photons bounce off.
« Last Edit: 08/05/2015 05:37 AM by meberbs »

Online ThinkerX

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Perhaps one of our intrepid DIY types here will be able to duplicate the experiment, minus most of the artefact producing bells and whistles. 

Something else I have been meaning to ask you:  David Bae's photon recycling laser system - the one requiring two spacecraft that amplifies photonic power 5000 times.   To me, despite being accepted as legit, it seems like
the static version could be twisted by a real clever engineer type into a free energy device (power output 5000 times greater than input).  A CoE violation.  You agree?

Also, if the EM Drive is somehow doing something similar, would that still constitute a violation of CoE?   
« Last Edit: 08/05/2015 09:35 AM by Carl G »

Offline deltaMass

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I'll be the first to point out that the folks here have probably had quite enough of me discussing CoE and over-unity. But to Bae...

I had the same thought. The situation is indeed similar. He is asking us to believe that thrust is proportional to the number of bounces, which is directly related to the Q. So he also has a P*Q factor in his thrust equation. And the obvious question is: how can it be that a cavity which is being pumped steady-state with input power P can yield a force that depends on P*Q? How can that be sustainable for seconds and minutes? It appears that one's extracting more than goes in. 

I confess to being uncertain about this. I saw his experiment where he got thrust that was indeed 2*P*Q/c. The saving grace might well be that photon mirrors only become efficient as the mirror velocity with respect to the light source approaches c. By this logic, he is only sipping at each beam, and despite the fact that multiple reflections are simultaneously in play (which intensifies the beam of course) he is only taking a small fraction out of each individual beam.

But that's an unsatisfactory explanation too, because one could engineer around it. Probably only a mathematical argument could settle it for me.
« Last Edit: 08/05/2015 09:35 AM by Carl G »

Offline TheTraveller

During the cordless and totally self contained rotary table EMDrive experiments, the following data will be monitored, data logged and streamed live.

Force generated - calculated
Angular velocity - measured
Angular acceleration - calculated & measured
Forward Rf power - measured
Reflected Rf power - measured
VSWR - calculated
Frequency - measured
Rf amp power consumed - measured
Internal frustum pressure - measured
End plate, side wall and ambient temperature - measured

Any comments on something else to monitor?
« Last Edit: 08/05/2015 09:04 AM by TheTraveller »
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Offline flux_capacitor

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Any comments on something else to monitor?

Filming both end plates with an IR camera to show mode shapes?

Offline Carl G

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A reminder. You need to quote members properly. It's very simple and avoids misquotes and no way of finding the original quote otherwise. It's a forum rule.

A good example:

Any comments on something else to monitor?

Filming both end plates with an IR camera to show mode shapes?

A bad example:

Quote
Any comments on something else to monitor?

Thanks.

Offline Silversheep2011

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During the cordless and totally self contained rotary table EMDrive experiments, the following data will be monitored, data logged and streamed live.

Force generated - calculated
Angular velocity - measured
Angular acceleration - calculated & measured
Forward Rf power - measured
Reflected Rf power - measured
VSWR - calculated
Frequency - measured
Rf amp power consumed - measured
Internal frustum pressure - measured
End plate, side wall and ambient temperature - measured

Any comments on something else to monitor?

If I'm reading Yang's 2014 paper: to quote about 1/2 way through: "When using a  work chamber, heat loss makes the skin produce heat deep cavity deformation within the fixed lower {limits?} bolt of thermal expansion and that the wall is outwardly convex; this volume change however is very small."

So another one to look for thermal distortion effects on the copper plates particularly perhaps the large flat end plate to  causing it to "bow out convex" it may be relevant in making slight volume changes.
 I'm not sure if you can measure with device powered on.

 but anyway picking a few set 'reference points' and coming back exactly to those points with a a set of feeler gauges with a steel ruler might do it.
 
note: it maybe that it takes several heating and cooling cycles to see "if" the effect exists [Hot skin on inside, cold skin on outside] for an analogy: Go look at your 'used' frypan in the kitchen and note the way its now has a warped flat surface compared to new. 

so makes sense to get a baseline now.
then again it may not be significant... who knows....?
 
 

Offline TheTraveller

Any comments on something else to monitor?

Filming both end plates with an IR camera to show mode shapes?

Thanks for the comment.

Mode shapes?

I expect the spherical waves will bounce off the matched spherical end plates with very little phase distortion. Ie the whole end plate should get uniformly hot.

As the end plates are 2mm thick oxygen free copper, if there were any localised heating, it might be hard to spot.

Will consider how to do this.
« Last Edit: 08/05/2015 10:49 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
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Offline SeeShells

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During the cordless and totally self contained rotary table EMDrive experiments, the following data will be monitored, data logged and streamed live.

Force generated - calculated
Angular velocity - measured
Angular acceleration - calculated & measured
Forward Rf power - measured
Reflected Rf power - measured
VSWR - calculated
Frequency - measured
Rf amp power consumed - measured
Internal frustum pressure - measured
End plate, side wall and ambient temperature - measured

Any comments on something else to monitor?
Time
Date
Local Magnetic Field
Apx location
Temperature
Humidity
A compass close by to view
Vibration
Digital Stop Watch
Heavy Power Devices locally ie: Transformers
Any High Voltage Power Lines
Turn off Any Fluorescent Lights or if needed screen in Faraday cage (transformer inside)

About all I can think of after the first sip cup of coffee.

Shell

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Shell, I didn't realize they were both gifs. When I click the big one to enlarge it makes me cross-eyed.

Looks like random bouncing. I don't really see any standing wave pattern to it. The antenna is offset from the middle? In that configuration, you may need to run the simulation longer to develop a standing wave that has more amplitude than the antenna. Once the Q factor takes over in the cavity, the antenna should be a smaller contribution. Since we are looking at such a short slice, and during the turn-on transient, I think what we see has more to do with the antenna than the cavity resonance, IMO.
Todd

Todd: you are 100% correct concerning this pattern.  Ditto for the previous run.  I examined the csv files and arrived at the same conclusion.
The previous runs with the dipole antenna in the middle had established clear TM11 standing wave modes. The last two runs are fluctuating, asymmetric fluctuations due to the antenna being very asymetrically placed. 
Placing the antenna in an asymmetric location in the Meep model (rather than centrally symmetrically located), rather than exciting a TE mode ends up producing very asymmetric fields and a lack of resonance  The Q is thousands of times lower.   There are no standing waves being formed. 

1) No conclusions should be ever be drawn without looking at the NUMERICAL MAGNITUDE of the response.   Runs should not be compared without taking into account that the electric and magnetic fields numerical magnitude patterns are much smaller than others.

2) Anything looking fractal or contour plots that are not smooth indicated noise and very low magnitude.

3) The Meep output for Q should be taken into account.  Q of millions (previous runs) means that the resistivity is way too low in the model.  Q's of thousands with the same model (when it should be millions, due to the unphysically low resisitvity) means lack of resonance.  The physical reality should not be confused with the numerical model.  The present numerical model gives a Q of millions (which is unphysical) when there is resonance,because the Drude model constants being used are tantamount to a superconducting cavity.  If the same Drude model (which is tantamount to superconductivity due to its effective very low resistivity) gives a Q of thousands it means that the cavity is not in resonance, since the Q is thousands of times lower than what it should be.  If people are uncomfortable with Q of millions, this can be addressed by changing the Drude model variables so that the resistivity is increased such that the Q becomes realistic.

Another observation: there has not been a single excitation of a TE mode in any MEEP run for Yang/Shell up to now.

Further exploration is required in order to find out how to excite TE modes using Meep.

Asymmetric location of the antenna just results in very asymmetric fields being excited.
« Last Edit: 08/05/2015 11:03 AM by Rodal »

Offline TheTraveller

During the cordless and totally self contained rotary table EMDrive experiments, the following data will be monitored, data logged and streamed live.

Force generated - calculated
Angular velocity - measured
Angular acceleration - calculated & measured
Forward Rf power - measured
Reflected Rf power - measured
VSWR - calculated
Frequency - measured
Rf amp power consumed - measured
Internal frustum pressure - measured
End plate, side wall and ambient temperature - measured

Any comments on something else to monitor?
Time
Date
Local Magnetic Field
Apx location
Temperature
Humidity
A compass close by to view
Vibration
Digital Stop Watch
Heavy Power Devices locally ie: Transformers
Any High Voltage Power Lines
Turn off Any Fluorescent Lights or if needed screen in Faraday cage (transformer inside)

About all I can think of after the first sip cup of coffee.

Shell

All the data will be logged every 10ms, (100 samples per second) with a microsecond resolution date and time clock.

Ambient temp is recorded.

Digital clock and live data will be part of the video stream.

Will add humidity even though the frustum is sealed and the pressure is monitored and logged. So no hot N2 jets.

Frustum is inside a Faraday Cage as is the RF amp. Raspberry 2B control system & Rf gen will be inside a cast metal box. All electrical leads will be shielded.

1st streamed run will be done in my workshop. If all goes well, the next streamed tests will be done at a local Uni's physics dept lab. We are in discussions for them to do a test and measurement run and write a paper for peer review on the results. Of course they need to see it working and have the data to analyse.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline TheTraveller

During the cordless and totally self contained rotary table EMDrive experiments, the following data will be monitored, data logged and streamed live.

Force generated - calculated
Angular velocity - measured
Angular acceleration - calculated & measured
Forward Rf power - measured
Reflected Rf power - measured
VSWR - calculated
Frequency - measured
Rf amp power consumed - measured
Internal frustum pressure - measured
End plate, side wall and ambient temperature - measured

Any comments on something else to monitor?

If I'm reading Yang's 2014 paper: to quote about 1/2 way through: "When using a  work chamber, heat loss makes the skin produce heat deep cavity deformation within the fixed lower {limits?} bolt of thermal expansion and that the wall is outwardly convex; this volume change however is very small."

So another one to look for thermal distortion effects on the copper plates particularly perhaps the large flat end plate to  causing it to "bow out convex" it may be relevant in making slight volume changes.
 I'm not sure if you can measure with device powered on.

 but anyway picking a few set 'reference points' and coming back exactly to those points with a a set of feeler gauges with a steel ruler might do it.
 
note: it maybe that it takes several heating and cooling cycles to see "if" the effect exists [Hot skin on inside, cold skin on outside] for an analogy: Go look at your 'used' frypan in the kitchen and note the way its now has a warped flat surface compared to new. 

so makes sense to get a baseline now.
then again it may not be significant... who knows....?

The freq tracking system will auto compensate for heating effects altering frustum resonance and the 2mm thick oxygen free copper end and wall thickness will distribute any localised heating very quickly. Input power is only 100w MAX and so don't expect much thermal dimensional changes.

Input power is totally programme controlled. From 79mWs to 100Ws in 1dBM steps. Will only use the power level that is required to get the rotary test rig to accelerate from 0 rpm to 120 rpm in a reasonable time. Stressing the Rf amp and the Frustum at max power is not on the agenda.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline TheTraveller

...The EM-Drive is just a rebranded perpetual motion machine...

Will enjoy watching you eat those words.

Have a folder of other such NSF quotes that will be posted after my test data is in.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

Offline TheTraveller

I've stumbled across a bit of difficulty.

Mr. Shawyer's theory paper cites Cullin, p3, Equation 15 indicates that the force from radiation pressure is proportional to guide wavelength.

Jones, p361 Table 1 that the force is in proportion to the phase velocity index of refraction, not the group velocity index.

Q: Is there an obvious reason why dielectric materials would behave differently from waveguides in this regard?

Thanks.

Shawyer's theory Paper
http://www.emdrive.com/theorypaper9-4.pdf

The Measurement of Optical Radiation Pressure in Dispersive Media
R. V. Jones and B. Leslie
Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences
Vol. 360, No. 1702 (Apr. 4, 1978), pp. 347-363
http://www.jstor.org/stable/79586

Absolute Power Measurement at Microwave Frequencies
A.L. Cullen
1951, Journal unknown.
https://dl.dropboxusercontent.com/u/3621645/1951%20Cullen%20Power%20at%20MW%20Frequencies%2011-09-1951.pdf


Inside a waveguide, nothing travels at phase velocity as it is above c. Information, energy and momentum travel at group velocity:

http://www.microwaves101.com/encyclopedias/waveguide-mathematics#velocity

Cullen, Shawyer and Prof Yang are correct, as attached, to use the guide wavelength inside their waveguides (other side of the same coin as group velocity) to calc the end plate reflected Force generation.
« Last Edit: 08/05/2015 11:10 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick

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