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#2040 by Rodal on 20 Jan, 2016 20:32
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Haven't fully followed up on those complex quantities. (good excuse for a "secret sauce")
Edit: (just made it to computer) Yes ... your edit is correct. Note all real gasses will have some imaginary components which will lower (?) the Q. By how much is a question.
Just got back again.. (troublesome vacuum equipment, as per usual)
Anyway, to continue, as the dielectric constant is increased, the frequency of the resonances decreases so the size of the cavity decreases for the same frequency and the Q decreases for the same surface conductivity as well as by the loss tangent of the dielectric. That may be close to breakeven or a slight loss ?
Yes, as the dielectric constant is increased the natural frequency decreases, for example for NASA, the natural frequency decreased from around 2.16 GHz to around 1.9 GHz, less than 15% decrease
The Q also decreases, as the result of the loss tangent. But here observe what we learnt from NASA: it was much better to use HDPE as a dielectric than to use Neoprene rubber as a dielectric. Although Neoprene rubber had a larger real part of the permittivity, Neoprene has also a much larger tan delta which resulted in lower Q and much lower "anomalous force".
Using HDPE (and PTFE which was almost as good, but HDPE appears better) they decreased the natural frequency just a little (less than 15) with minimal decrease in Q (they got Q=20,000) because HDPE has such a small value of tan delta.
Also, of course the size of the dielectric plays a role. They amount of volume taken by the HDPE is relatively small and placed at the small end.
That's regarding polymers as a dielectric.
___________________________
I don't have the tan delta for Ammonia (let me know if you find a value), but strictly going on the fact that Ammonia is used so successfully in Masers (of course due to emitting at 24 GHz) it seems that Ammonia is certainly worth a try
So the idea is to let the frequency fall (not a problem w/ a variable source) and optimize the thickness of (still got to look at that) the dielectric at the small end (I agree, that is the best position) using some dielectric w/ a minimum loss tangent.
That is very well stated. I agree. I have to look back and see how Paul March selected the thickness of the dielectric (probably he did it on the the basis of Prof. Woodward's hypothesis), but I'm sure that he realized that having a small tan delta was important, as I recall discussing that with him (the best dielectrics he tested: HDPE and PTFE have very small tan delta values).
QUESTION: What happened with your force equation for an asymmetrically placed dielectric in a cylindrical cavity?
I could not find that equation in the Hypothesis page in the Wiki. -
#2041 by rfmwguy on 20 Jan, 2016 20:41
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Sorry you feel this way after just one observational experiment. Normally, I would have left your post uncommented on, but for this paragraph:Update on FEKO.
Lite will not run my frustum and I've heard others telling me the same thing.
Also: (quote) Full FEKO evaluation license valid for 45 days is no longer available. Only the FEKO LITE version which is a restricted version is available to download for free.(end quote)
Nice user interface and I was able to model my frustum and the change I wanted quite quickly but that's where it stopped. They want you to buy the full version and I'm waiting for some pricing.
Shell
There are other programs beside FEKO.
RFPlumber has access to COMSOL and has used it effectively. COMSOL can readily calculate the natural frequencies and mode shapes of cavities with asymmetrically placed dielectrics. Also COMSOL can readily display numerical values of the electromagnetic fields in SI units for a 3-D truncated cone that is readily digested and understood.
Sorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order tokeep the illusion alive, stay in business, get more fundingwhatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature.
"At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order tokeep the illusion alive, stay in business, get more fundingwhatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature."
Speaking for myself only, I counter that there IS credible evidence, depending on what you define as "credible". Monitor the aiaa.org website for a paper release soon for your evidence. Secondly, you insinuate people bend the facts which I find disingenuous as you have no proof of this. This is unscientific and intellectually dishonest. Thirdly, its actually a sign of the BEST of human nature; to question, collaborate and ponder "what if". This citizen science project was not for you and I get that, but please don't diss the community, many from both sides I consider my friends.
Speaking as the Moderator of this community, I appreciate you contribution and your are welcome to continue to follow the projects here and elsewhere. -
#2042 by Rodal on 20 Jan, 2016 20:54
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...Sorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground....
I call this the "tar baby aspect of the EM Drive":
Quote"I'll learn ya!" Brer Rabbit yelled. He took a swing at the cute little Tar Baby and his paw got stuck in the tar.
"Lemme go or I'll hit you again," shouted Brer Rabbit. The Tar Baby, she said nothing.
"Fine! Be that way," said Brer Rabbit, swinging at the Tar Baby with his free paw. Now both his paws were stuck in the tar, and Brer Fox danced with glee behind the bushes.
"I'm gonna kick the stuffin' out of you," Brer Rabbit said and pounced on the Tar Baby with both feet. They sank deep into the Tar Baby. Brer Rabbit was so furious he head-butted the cute little creature until he was completely covered with tar and unable to move.
Compensating for this, it is fun and intellectually stimulating to have these discussions with the NSF community
-
#2043 by SeeShells on 20 Jan, 2016 21:13
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http://forum.nasaspaceflight.com/index.php?topic=39004.msg1480658#msg1480658Quote
Sorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order to keep the illusion alive, stay in business, get more funding whatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature.
RFPlumber,
You maybe right, maybe there is nothing there and we're wasting our time, but when I read your comments I couldn't help but remember a email from Paul March of EagleWorks and I'll re-post it here lest we forget.
Shell
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
All:
I wish I could show you all the pictures I've taken on how we saluted and mitigated the issues raised by our EW Lab's Blue-Ribbon PhD panel and now Potomac-Neuron's paper, on the possible Lorentz force interactions. That being the Lorentz Interactions with the dc currents on the EW torque pendulum (TP) with the stray magnetic fields from the torque pendulum's first generation open-face magnetic damper and the Earth's geomagnetic field, but I can't due to the restrictive NASA press release rules now applied to the EW Lab.
However since I still can't show you this supporting data until the EW Lab gets our next peer-reviewed lab paper published, I will tell you that we first built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. I also changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. Finally we rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Current null testing with both the 50 ohm dummy load and with the integrated test article rotated 90 degrees with respect to the TP sensitive axis now show less than one uN of Lorentz forces on the TP due to dc magnetic interactions with the local environment even when drawing the maximum RF amp dc current of 12 amps.
Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938 -
#2044 by SeeShells on 20 Jan, 2016 21:55
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...Sorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground....
I call this the "tar baby aspect of the EM Drive":Quote"I'll learn ya!" Brer Rabbit yelled. He took a swing at the cute little Tar Baby and his paw got stuck in the tar.
"Lemme go or I'll hit you again," shouted Brer Rabbit. The Tar Baby, she said nothing.
"Fine! Be that way," said Brer Rabbit, swinging at the Tar Baby with his free paw. Now both his paws were stuck in the tar, and Brer Fox danced with glee behind the bushes.
"I'm gonna kick the stuffin' out of you," Brer Rabbit said and pounced on the Tar Baby with both feet. They sank deep into the Tar Baby. Brer Rabbit was so furious he head-butted the cute little creature until he was completely covered with tar and unable to move.
Compensating for this, it is fun and intellectually stimulating to have these discussions with the NSF community
Few things in science remain questionable and within the grasp and budgets of individuals other than astronomy and the newest Pet Rock. (unless you're Elon Musk)....
Shell -
#2045 by RFPlumber on 20 Jan, 2016 22:05
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Sorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order tokeep the illusion alive, stay in business, get more fundingwhatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature.
Sorry you feel this way after just one observational experiment. Normally, I would have left your post uncommented on, but for this paragraph:
"At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order tokeep the illusion alive, stay in business, get more fundingwhatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature."
Speaking for myself only, I counter that there IS credible evidence, depending on what you define as "credible". Monitor the aiaa.org website for a paper release soon for your evidence. Secondly, you insinuate people bend the facts which I find disingenuous as you have no proof of this. This is unscientific and intellectually dishonest. Thirdly, its actually a sign of the BEST of human nature; to question, collaborate and ponder "what if". This citizen science project was not for you and I get that, but please don't diss the community, many from both sides I consider my friends.
...
There are always seem to be some un-anticipated side effects... There is nothing wrong with this community. It was not my intention at all to somehow offend anyone here, or hurt anyone's feelings. Quite the opposite, I just spent a few months of my spare time and a few thousand dollars contributing to the effort and pursuing something which most likely does not even exist, and most certainly does not exist at the levels, which some people go out of their way to make others believe. I feel somewhat cheated But then I only have myself to blame. All the papers are out there, all it takes is to read them slowly and carefully and without bias. And then add the remaining known facts about the history of this saga. For those with too much excitement, like myself and a few others here, it does not hurt to go and try to replicate the experiment. But in hindsight this likely wasn't strictly necessary in my case. I just happened to miss the part that EW 200 uN result was before their tests in vacuum. I wouldn't have started this project if I knew up front about their in-vacuum result, yet the way their paper is written does not make it particularly easy to confirm this simple fact. Apparently, this has already been pointed out on this same forum before (I happened to stumble on the post when googling for something else, and was stunned when it turned out to be true).
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#2046 by rq3 on 20 Jan, 2016 22:17
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Update on FEKO.
Lite will not run my frustum and I've heard others telling me the same thing.
Also: (quote) Full FEKO evaluation license valid for 45 days is no longer available. Only the FEKO LITE version which is a restricted version is available to download for free.(end quote)
Nice user interface and I was able to model my frustum and the change I wanted quite quickly but that's where it stopped. They want you to buy the full version and I'm waiting for some pricing.
Shell
"The other" thread is now showing dielectric insert designs thanks to FEKO (while in this thread we are just talking about dielectrics
):
https://www.reddit.com/r/EmDrive/comments/41slhi/the_islandplaya_virtual_em_drive/
This includes a FEKO a S-parameter plot (never seen an S-parameter plot produced by Meep users ), including calculation of the frequency bandwidth
Acknowledgement to Island Playa and FEKO for the images below
It's fascinating to sit here and watch everyone re-invent the Dielectric Resonant Oscillator (DRO). -
#2047 by Rodal on 20 Jan, 2016 23:36
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Update on FEKO.
Lite will not run my frustum and I've heard others telling me the same thing.
Also: (quote) Full FEKO evaluation license valid for 45 days is no longer available. Only the FEKO LITE version which is a restricted version is available to download for free.(end quote)
Nice user interface and I was able to model my frustum and the change I wanted quite quickly but that's where it stopped. They want you to buy the full version and I'm waiting for some pricing.
Shell
"The other" thread is now showing dielectric insert designs thanks to FEKO (while in this thread we are just talking about dielectrics ):
https://www.reddit.com/r/EmDrive/comments/41slhi/the_islandplaya_virtual_em_drive/
This includes a FEKO a S-parameter plot (never seen an S-parameter plot produced by Meep users ), including calculation of the frequency bandwidth
Acknowledgement to Island Playa and FEKO for the images below
It's fascinating to sit here and watch everyone re-invent the Dielectric Resonant Oscillator (DRO).
Shawyer apparently used similar dielectric materials as used in Dielectric Resonant Oscillators (DRO): ceramics with high relative electric permittivity values, but Shawyer is reported to have abandoned the use of these materials, and it is reported that Shawyer did not use these ceramic dielectric materials in his Demonstrator or FLight Thruster experiments. Shawyer is reported to have abandoned these ceramic dielectrics because they lowered the Q and resulted in lower anomalous force. In one of his patents (UK Patent Application GB 2 334 761 A, date of publication 01.09.1999, application No 9809035.0, date of filing 29.04.1998), Shawyer reports using a dielectric ceramic with relative permittivity =38
Paul March discussed the use of a number of materials as dielectrics for the EM Drive. My recollection is that the use of ceramics as used in DRO's produced no significant values of the "anomalous thrust", and that they settled with HDPE and PTFE, that have much lower values of relative permittivity. Although HDPE has much lower value of relative electric permittivity (2.26@1-3GHz), it resulted in the highest value of "anomalous thrust" of all the materials they tested.
Picture of a dielectric resonant oscillator with a ceramic cylinder dielectric:
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#2048 by zen-in on 20 Jan, 2016 23:41
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...
There are always seem to be some un-anticipated side effects... There is nothing wrong with this community. It was not my intention at all to somehow offend anyone here, or hurt anyone's feelings. Quite the opposite, I just spent a few months of my spare time and a few thousand dollars contributing to the effort and pursuing something which most likely does not even exist, and most certainly does not exist at the levels, which some people go out of their way to make others believe. I feel somewhat cheated But then I only have myself to blame. All the papers are out there, all it takes is to read them slowly and carefully and without bias. And then add the remaining known facts about the history of this saga. For those with too much excitement, like myself and a few others here, it does not hurt to go and try to replicate the experiment. But in hindsight this likely wasn't strictly necessary in my case. I just happened to miss the part that EW 200 uN result was before their tests in vacuum. I wouldn't have started this project if I knew up front about their in-vacuum result, yet the way their paper is written does not make it particularly easy to confirm this simple fact. Apparently, this has already been pointed out on this same forum before (I happened to stumble on the post when googling for something else, and was stunned when it turned out to be true).
I think you are justified in being somewhat peeved that some information appears to be misrepresented. That is part of the long drawn out saga of the em-drive. Maybe it's due to the tendancy of inventors to not want to disclose everything and to puff up what they have done and to obfuscate any who they perceive to be competitors. Elisha Gray would be one to agree with that modus operandi. I think you have earned the right to be critical and to make yourself unpopular; although I'm sure that is not your intent. You built a test unit and performed your experiments in a professional and exacting way. No one can accuse you of fudging your data or of jumping to conclusions. That is how science is done and everyone can learn from your example. -
#2049 by zen-in on 20 Jan, 2016 23:48
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http://forum.nasaspaceflight.com/index.php?topic=39004.msg1480658#msg1480658
QuoteSorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order to keep the illusion alive, stay in business, get more funding whatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature.
RFPlumber,
You maybe right, maybe there is nothing there and we're wasting our time, but when I read your comments I couldn't help but remember a email from Paul March of EagleWorks and I'll re-post it here lest we forget.
Shell
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
All:
I wish I could show you all the pictures I've taken on how we saluted and mitigated the issues raised by our EW Lab's Blue-Ribbon PhD panel and now Potomac-Neuron's paper, on the possible Lorentz force interactions. That being the Lorentz Interactions with the dc currents on the EW torque pendulum (TP) with the stray magnetic fields from the torque pendulum's first generation open-face magnetic damper and the Earth's geomagnetic field, but I can't due to the restrictive NASA press release rules now applied to the EW Lab.
However since I still can't show you this supporting data until the EW Lab gets our next peer-reviewed lab paper published, I will tell you that we first built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. I also changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. Finally we rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Current null testing with both the 50 ohm dummy load and with the integrated test article rotated 90 degrees with respect to the TP sensitive axis now show less than one uN of Lorentz forces on the TP due to dc magnetic interactions with the local environment even when drawing the maximum RF amp dc current of 12 amps.
Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
And where is this blue ribbon peer reviewed paper? It's been over 2 months since Paul March's post where he more or less acknowledges the anomalous thrust is a thermal phenomena when tested in a vacuum. If there really is an em-drive thrust at STP it won't be useful in outer space. The NASA EW program appears to be just fading away, like so many others. -
#2050 by Rodal on 20 Jan, 2016 23:55
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...
I think that NASA Eagleworks is still functioning and Paul March and Dr. White are still there.
And where is this blue ribbon peer reviewed paper? It's been over 2 months since Paul March's post where he more or less acknowledges the anomalous thrust is a thermal phenomena when tested in a vacuum. If there really is an em-drive thrust at STP it won't be useful in outer space. The NASA EW program appears to be just fading away, like so many others.
Prof. Yang we understand is retired and writing poetry as per the latest information posted in this thread. When it was first reported that Prof. Yang was no longer working in the EM Drive, TheTraveller said he was going to check this information with Roger Shawyer. I don't recall reading an update from TT on this, and it has been some time since that information was disclosed, so apparently nobody has denied the veracity of that information.
Tajmar was supposed to continue his EM Drive testing, according to his paper, but there are no updates on his website.
TheTraveller posted this about Shawyer going to be featured in a BBC Horizons program, and also NASA (Eagleworks ?), about 3 months ago:
https://forum.nasaspaceflight.com/index.php?topic=38577.msg1437386#msg1437386
but I don't recall if it actually happened or whether it is going to happen, and if so when, does anybody know?
-
#2051 by SeeShells on 21 Jan, 2016 00:28
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http://forum.nasaspaceflight.com/index.php?topic=39004.msg1480658#msg1480658
QuoteSorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order to keep the illusion alive, stay in business, get more funding whatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature.
RFPlumber,
You maybe right, maybe there is nothing there and we're wasting our time, but when I read your comments I couldn't help but remember a email from Paul March of EagleWorks and I'll re-post it here lest we forget.
Shell
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
All:
I wish I could show you all the pictures I've taken on how we saluted and mitigated the issues raised by our EW Lab's Blue-Ribbon PhD panel and now Potomac-Neuron's paper, on the possible Lorentz force interactions. That being the Lorentz Interactions with the dc currents on the EW torque pendulum (TP) with the stray magnetic fields from the torque pendulum's first generation open-face magnetic damper and the Earth's geomagnetic field, but I can't due to the restrictive NASA press release rules now applied to the EW Lab.
However since I still can't show you this supporting data until the EW Lab gets our next peer-reviewed lab paper published, I will tell you that we first built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. I also changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. Finally we rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Current null testing with both the 50 ohm dummy load and with the integrated test article rotated 90 degrees with respect to the TP sensitive axis now show less than one uN of Lorentz forces on the TP due to dc magnetic interactions with the local environment even when drawing the maximum RF amp dc current of 12 amps.
Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
And where is this blue ribbon peer reviewed paper? It's been over 2 months since Paul March's post where he more or less acknowledges the anomalous thrust is a thermal phenomena when tested in a vacuum. If there really is an em-drive thrust at STP it won't be useful in outer space. The NASA EW program appears to be just fading away, like so many others.
You would expect to see it take time if questions arise from the peer review of EagleWorks theories and data. Realize if EagleWorks and Dr. Harold Sonny White is still proposing his Quantum Vacuum Virtual Particle theory or a modified one from the last presentation it will be a revolution in current theories and I'd expect it to take time. This is the other side of your question. I would encourage patience.
Shell
verbiage garbage corrected -
#2052 by rfmwguy on 21 Jan, 2016 01:00
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I would suggest checking this link from time to time for the possibility of a new peer reviewed journal paper from ew:
http://arc.aiaa.org/action/doSearch?displaySummary=true&contents=articlesChapters&AllField=&Title=Anomalous+Thrust+Production&
Since new papers are released to a variety of journals, I have no idea which one might be their choice, I simply created a search using the first words of their old conference paper assuming these words might be included in a potential new journal paper. This search will also bring up the old conference paper as well.
Disclaimer: No inside info here, just some logical guesses as to where a new journal paper might appear. -
#2053 by forgravity on 21 Jan, 2016 01:17
-
...
I think that NASA Eagleworks is still functioning and Paul March and Dr. White are still there.
And where is this blue ribbon peer reviewed paper? It's been over 2 months since Paul March's post where he more or less acknowledges the anomalous thrust is a thermal phenomena when tested in a vacuum. If there really is an em-drive thrust at STP it won't be useful in outer space. The NASA EW program appears to be just fading away, like so many others.
Prof. Yang we understand is retired and writing poetry as per the latest information posted in this thread. When it was first reported that Prof. Yang was no longer working in the EM Drive, TheTraveller said he was going to check this information with Roger Shawyer. I don't recall reading an update from TT on this, and it has been some time since that information was disclosed, so apparently nobody has denied the veracity of that information.
Tajmar was supposed to continue his EM Drive testing, according to his paper, but there are no updates on his website.
TheTraveller posted this about Shawyer going to be featured in a BBC Horizons program, and also NASA (Eagleworks ?), about 3 months ago:
https://forum.nasaspaceflight.com/index.php?topic=38577.msg1437386#msg1437386
but I don't recall if it actually happened or whether it is going to happen, and if so when, does anybody know?
Based on this it sounds like it will be released around Feb.
https://www.reddit.com/r/EmDrive/comments/3y2tfc/roger_shawyers_email_to_all_emdrive_builders/ -
#2054 by TheTraveller on 21 Jan, 2016 03:13
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Disclaimer: No inside info here, just some logical guesses as to where a new journal paper might appear.
Would suggest it will also show up on the NASA search site under Dr. Harold White:
http://ntrs.nasa.gov/search.jsp?Nm=4294903350|Author|White,%20Harold&N=0 -
#2055 by Prunesquallor on 21 Jan, 2016 03:26
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http://forum.nasaspaceflight.com/index.php?topic=39004.msg1480658#msg1480658
QuoteSorry, I am not likely to be spending much more time on this effort other than to write a summary paper. At this point the "EmDrive" at DIY level is obviously just an RF playground. There is literally zero credible evidence that any experiment to date has produced any abnormal force anywhere above the noise level. Note the word credible above, as it is simply unbelievable to what extremes people are willing to bend and massage the facts in order to keep the illusion alive, stay in business, get more funding whatever their agenda is. This was a fun exercise in RF techniques, but even more so this was just another sad encounter with human nature.
RFPlumber,
You maybe right, maybe there is nothing there and we're wasting our time, but when I read your comments I couldn't help but remember a email from Paul March of EagleWorks and I'll re-post it here lest we forget.
Shell
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
All:
I wish I could show you all the pictures I've taken on how we saluted and mitigated the issues raised by our EW Lab's Blue-Ribbon PhD panel and now Potomac-Neuron's paper, on the possible Lorentz force interactions. That being the Lorentz Interactions with the dc currents on the EW torque pendulum (TP) with the stray magnetic fields from the torque pendulum's first generation open-face magnetic damper and the Earth's geomagnetic field, but I can't due to the restrictive NASA press release rules now applied to the EW Lab.
However since I still can't show you this supporting data until the EW Lab gets our next peer-reviewed lab paper published, I will tell you that we first built and installed a 2nd generation, closed face magnetic damper that reduced the stray magnetic fields in the vacuum chamber by at least an order of magnitude and any Lorentz force interactions it could produce. I also changed up the torque pendulum's grounding wire scheme and single point ground location to minimize ground loop current interactions with the remaining stray magnetic fields and unbalanced dc currents from the RF amplifier when its turned on. This reduced the Lorentz force interaction to less than 2 micro-Newton (uN) for the dummy load test. Finally we rebuilt the copper frustum test article so that it is now fully integrated with the RF VCO, PLL, 100W RF amp, dual directional coupler, 3-stub tuner and connecting coax cables, then mounted this integrated test article at the opposite end of the torque pendulum, as far away as possible from the 2nd generation magnetic damper where only the required counterbalance weights now reside. Current null testing with both the 50 ohm dummy load and with the integrated test article rotated 90 degrees with respect to the TP sensitive axis now show less than one uN of Lorentz forces on the TP due to dc magnetic interactions with the local environment even when drawing the maximum RF amp dc current of 12 amps.
Given all of the above TP wiring and test article modifications with respect to our 2014 AIAA/JPC paper design baseline needed to address these Lorentz force magnetic interaction issues, we are still seeing over 100uN of force with 80W of RF power going into the frustum running in the TM212 resonant mode, now in both directions, dependent on the direction of the mounted integrated test article on the TP. However these new plus and minus thrust signatures are still contaminated by thermally induced TP center of gravity (cg) zero-thrust baseline shifts brought on by the expansion of the copper frustum and aluminum RF amp and its heat sink when heated by the RF, even though these copper and aluminum cg shifts are now fighting each other. (Sadly these TP cg baseline shifts are ~3X larger in-vacuum than in-air due to the better insulating qualities of the vacuum, so the in-vacuum thrust runs look very thermally contaminated whereas the in-air run look very impulsive.) So we have now developed an analytical tool to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP. Not being satisfied with just this analytical impulsive vs thermal signal separation approach, we are now working on a new integrated test article subsystem mounting arrangement with a new phase-change thermal management subsystem that should mitigate this thermally induced TP cg baseline shift problem once and for-all.
And yet the anomalous thrust signals remain...
Best, Paul March
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
And where is this blue ribbon peer reviewed paper? It's been over 2 months since Paul March's post where he more or less acknowledges the anomalous thrust is a thermal phenomena when tested in a vacuum. If there really is an em-drive thrust at STP it won't be useful in outer space. The NASA EW program appears to be just fading away, like so many others.
Wow, I respectfully suggest you actually READ the material you quoted. Paul said the vacuum tests look "very thermally contaminated" but EW has come up with a tool "to help separate the EM-Drive thrust pulse waveform contributions from the thermal expansion cg induced baseline shifts of the TP". He does NOT acknowledge the anomalous thrust is a thermal phenomenon, neither "more or less".
I suggest you do not try to interpret what he says, but rather take it literally.
And as I've written before, even IF for some bizarre reason the EMDrive needed to be pressurized to work, so what? Pressurize it and run it in outer space. It's a closed frustum and nothing comes flowing out the back. -
#2056 by Tellmeagain on 21 Jan, 2016 03:46
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I would suggest checking this link from time to time for the possibility of a new peer reviewed journal paper from ew:
http://arc.aiaa.org/action/doSearch?displaySummary=true&contents=articlesChapters&AllField=&Title=Anomalous+Thrust+Production&
Since new papers are released to a variety of journals, I have no idea which one might be their choice, I simply created a search using the first words of their old conference paper assuming these words might be included in a potential new journal paper. This search will also bring up the old conference paper as well.
Disclaimer: No inside info here, just some logical guesses as to where a new journal paper might appear.
The AIAA conference papers are not peer-reviewed. I remembered I once checked their requirement and got to know that they reviewed the abstracts only. -
#2057 by TheTraveller on 21 Jan, 2016 03:50
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And as I've written before, even IF for some bizarre reason the EMDrive needed to be pressurized to work, so what? Pressurize it and run it in outer space. It's a closed frustum and nothing comes flowing out the back.
You do note the very large number of end plate securing bolts employed in the Flight Thruster. Would suggest to me that whatever is inside the Flight Thruster is designed to stay there no matter where the Flight Thruster is operated.
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#2058 by Tellmeagain on 21 Jan, 2016 03:54
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There are always seem to be some un-anticipated side effects... There is nothing wrong with this community. It was not my intention at all to somehow offend anyone here, or hurt anyone's feelings. Quite the opposite, I just spent a few months of my spare time and a few thousand dollars contributing to the effort and pursuing something which most likely does not even exist, and most certainly does not exist at the levels, which some people go out of their way to make others believe. I feel somewhat cheated
But then I only have myself to blame. All the papers are out there, all it takes is to read them slowly and carefully and without bias. And then add the remaining known facts about the history of this saga. For those with too much excitement, like myself and a few others here, it does not hurt to go and try to replicate the experiment. But in hindsight this likely wasn't strictly necessary in my case. I just happened to miss the part that EW 200 uN result was before their tests in vacuum. I wouldn't have started this project if I knew up front about their in-vacuum result, yet the way their paper is written does not make it particularly easy to confirm this simple fact. Apparently, this has already been pointed out on this same forum before (I happened to stumble on the post when googling for something else, and was stunned when it turned out to be true).
Thank you for your nice work. It was well designed and well carried out. It is true that one needs to read the EW paper carefully to get everything. I think I read more than 5 times, expect for the speculation section, which I have not read even once. -
#2059 by Prunesquallor on 21 Jan, 2016 04:14
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And as I've written before, even IF for some bizarre reason the EMDrive needed to be pressurized to work, so what? Pressurize it and run it in outer space. It's a closed frustum and nothing comes flowing out the back.
You do note the very large number of end plate securing bolts employed in the Flight Thruster. Would suggest to me that whatever is inside the Flight Thruster is designed to stay there no matter where the Flight Thruster is operated.
Yep. But you could also enclose the whole thruster inside a pressurized compartment if you wanted to. That is if there really is nothing material being exhausted out of it.
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