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#2640 by Rodal on 07 Nov, 2017 19:58
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TU Dresden reported achieving Q from 40,000 to 500,000, according to my recollection (will have to wait for video to confirm)
There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it....
1) Isn't that much better than the Q's from Eagleworks?
2) Wouldn't an un-symmetric electromagnetic field inside the EM Drive result in much lower Q's (rather than higher Q's)? Calculations show that the most symmetric TE modes like TE012 lead to highest Q
3) <<put the input at one end or the other. Not only is it better for exciting symmetrical TE modes>> That's not my understanding from the literature, particularly the books by Robert Collin. The high Q's reported by TU Dresden argue in favor of the placement of their antenna.
In the center of the TE excited cavity, you just have an axial magnetic field.
Perhaps X_Ray can throw further light on this matter, as I recall that X_Ray had studied the placement of the antenna using several computer programs.
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#2641 by dustinthewind on 07 Nov, 2017 20:23
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One method to eliminate the earths magnetic field is to use the Helmholtz coils.
Another method that can work is to encase the moving part of the pendulum in a ferrous box that moves with it and then separately encase that in a non-moving ferrous box. The non-moving ferrous box shunts the earths magnetic field around the apparatus while the ferrous box that moves with the pendulum arm shunts any magnetic fields from the the pendulum back to the pendulum. It should minimize any magnetic fields between the non-moving ferrous box and the pendulum arm that could cause interference.
-Not sure the 2nd option isn't more complicated than the 1st.
-A way of eliminating thermal effects could be built into the ferrous box apparatus as a possible bonus - insulation maybe. -
#2642 by WarpTech on 07 Nov, 2017 20:28
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TU Dresden reported achieving Q from 40,000 to 500,000
There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it....
1) Isn't that much better than the Q's from Eagleworks?
2) Wouldn't an un-symmetric electromagnetic field inside the EM Drive result in much lower Q's (rather than higher Q's)? Calculations show that the most symmetric TE modes like TE012 lead to highest Q
3) <<put the input at one end or the other. Not only is it better for exciting symmetrical TE modes>> That's not my understanding from the literature, particularly the books by Robert Collin. The high Q's reported by TU Dresden argue in favor of the placement of their antenna.
In the center of the TE excited cavity, you just have an axial magnetic field.
Perhaps X_Ray can throw further light on this matter, as I recall that X_Ray had studied the placement of the antenna using several computer programs.
I recall Jamie did a lot of different antenna simulations to get the best 50-Ohm matching impedance location. He determined that to be on the axis of the frustum.
IMO, as an expert Power Transformer designer; I would want to drive the resonant field the same way I would drive the secondary coil of a transformer. Considering the loop antenna as the primary coil, I want the two coils to be concentric (on the same axis) to maximize the coupling of the axial magnetic field, and the circular electric field parallel to the antenna wire. It is the magnetic gauge potential that provides the coupling, so we want this field to be parallel and concentric to both coils. If the antenna is on the side wall, it would be like designing a transformer with two orthogonal coils. No... just no!
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#2643 by Star-Drive on 07 Nov, 2017 21:10
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Paul,
Jose':
"Can you make sense out of that as something that is not an artifact due to external magnetic fields?"
Why yes I can, and so can Dr. White using his Q-Thruster conjecture based on the reality of the Quantum Vacuum (QV) as pointed out by Todd (WarpTech) in the quote from Milonni's "The Quantum Vacuum" Quantum Electrodynamics (QED) book.
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I understand that (the quoted) Dr. Milonni himself does not support White's explanation of the Quantum Vacuum as a means of propulsion for the EM Drive tested at Eagleworks.
We certainly missed you being there to argue in favor of White's theory and to argue (separately) for the validity of the test results at Eagleworks. Several experts on Quantum Mechanics were there: Prof. John Cramer (author of the excellent book "The Quantum Handshake" which I highly recommend: https://www.amazon.com/Quantum-Handshake-Entanglement-Nonlocality-Transactions/dp/3319246402/ref=sr_1_1?ie=UTF8&qid=1510085833&sr=8-1&keywords=the+quantum+handshake and Prof. Ray Chiao of Berkeley (now at Merced).
The discussion about focusing the force: the EM Drive made at TU Dresden had a Q (40,000 to 500,000) higher than those reported by Eagleworks. Shouldn't it have been better "focused"?
But let's get to experimental facts, instead of discussing controversial theories. There are more theories than physicists, and in the end what matters are experimental results.
Did NASA Eagleworks ever place the EM Drive with the longitudinal axis parallel to the arms of the torsional pendulum and measured a force perpendicular to the pendulum's arms?
Did Eagleworks also measure a considerable force in this direction?
Thanks
Jose':
"Did NASA Eagleworks ever place the EM Drive with the longitudinal axis parallel to the arms of the torsional pendulum and measured a force perpendicular to the pendulum's arms?[/b][/color]"
Yes we did. See attached slide of the Integrated Copper Frustum Test Article (ICFTA) as mounted with its longitudinal thrust axis parallel to the torque pendulum arm with its small OD end pointed to the vacuum chamber door. Due to an obstruction issue we could not mount the ICFTA with the BOD end pointed toward the vacuum chamber door.
"Did Eagleworks also measure a considerable force in this direction?"
Define considerable. With 60W of RF applied we measured anywhere ~10 to ~30 uN of prompt side thrust that was not attributed to the thermal center of gravity shifts we were trying to quantify in this test series. See attached slide with the first data run in this series. I also noticed in this test series that the phase adjustment of the coaxial phase adjuster had a marked affect on the thrust magnitude and direction.
As to defending Dr. White's QV conjecture I think there is a strong kernel of truth in his work that parallels Paul Murad's and John Brandenburg's Gravity E&M or GEM work. See attached papers. The rest is up to Sonny.
Best, Paul March
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#2644 by Star-Drive on 07 Nov, 2017 21:24
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TU Dresden reported achieving Q from 40,000 to 500,000
There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it....
1) Isn't that much better than the Q's from Eagleworks?
2) Wouldn't an un-symmetric electromagnetic field inside the EM Drive result in much lower Q's (rather than higher Q's)? Calculations show that the most symmetric TE modes like TE012 lead to highest Q
3) <<put the input at one end or the other. Not only is it better for exciting symmetrical TE modes>> That's not my understanding from the literature, particularly the books by Robert Collin. The high Q's reported by TU Dresden argue in favor of the placement of their antenna.
In the center of the TE excited cavity, you just have an axial magnetic field.
Perhaps X_Ray can throw further light on this matter, as I recall that X_Ray had studied the placement of the antenna using several computer programs.
Jose':
In my opinion the QV slosh pattern of the frustum is driven first by the shape of the frustum and the driven resonant mode with its associated ExB Poynting vectors and then the product of the loaded Q-factor times the input power. So the key factor in determining the QV slosh pattern is what the various ExB Poynting vectors are established over a full RF cycle, with a given frustum shape, and the selected resonant mode. In other words its really hard to beat the Mach Lorentz Thruster (MLT) with its geometrically well defined E-and B-fields when it comes to a well culminated and focused QV flow pattern.
Best, Paul M. -
#2645 by SteveD on 07 Nov, 2017 21:26
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There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it....
2) Wouldn't an un-symmetric electromagnetic field inside the EM Drive result in much lower Q's (rather than higher Q's)? Calculations show that the most symmetric TE modes like TE012 lead to highest Q
Actually under KISS the asymmetry is created by EM/photons moving more swiftly through the center of the can than KE around the skin. This is a result of the geometry of the can. A symmetrical field in the center of the can does not preclude an EM drive effect based on the cans asymmetrical geometry. -
#2646 by SteveD on 07 Nov, 2017 22:05
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Sigh KISS theory:
There are two frames of reference in the EMDrive. The rest frame and the motive frame.
The motive frame is created when a photon hits and bounces off point C. This causes a photon rocket effect.
The photon now travels by the most direct possible path to the end plate.
the length of line CD is c * t where c is the speed of light and t is the time elapsed sing emission of the photon at point C.
Line CA is of length Sqrt(CD^2+0.5AB^2) this length must be longer than c * t.
Because of this point A is outside of the light cone of point C when the photon arrived at point D.
Since point D cannot accelerate without point A first accelerating it is in the rest reference frame.
Geometry, plus the speed of light, has split one device into two reference frames. The acceleration has not happened yet for point A. It is not in the proper light cone. As far as point A is concerned everything is as it was before the release of the photon at point D.
Relativity has isolated Point C and Point D from each other as far as acceleration is concerned. The two points might as well be unattached to each other and floating freely in space. The effect is the same as a photonic laser thruster.
Now things get interesting. The Photon has increased the kinetic energy of motive frame by 0.5mvs^2 where v2 is the new velocity of the rocket.
It has only decreased the velocity of the rest frame by 0.5mv1^2 where v1 is the original velocity of the drive.
This leaves KE = v2^2 - v1^2 as yet to be accounted for.
Now my hunch is that this generates a mass fluctuation giving rise to a Mach effect as the can interacts with universal gravitation in order to preserve Noether's theorum (translation, it has to move and it has to interact with an external field to do so).
If the EM enters the can from the side, the same effect could conceivably created a lateral movement as the photons bounce around and generate the effect in a pattern more complex than simply moving from point C to Point D in a optimal line.
The key is that relativity has created two reference frames in what appears to be one solid unit.
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#2647 by rq3 on 07 Nov, 2017 22:34
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Paul,
Jose':
"Can you make sense out of that as something that is not an artifact due to external magnetic fields?"
Why yes I can, and so can Dr. White using his Q-Thruster conjecture based on the reality of the Quantum Vacuum (QV) as pointed out by Todd (WarpTech) in the quote from Milonni's "The Quantum Vacuum" Quantum Electrodynamics (QED) book.
...
I understand that (the quoted) Dr. Milonni himself does not support White's explanation of the Quantum Vacuum as a means of propulsion for the EM Drive tested at Eagleworks, and certainly nobody I can recall that spoke at the workshop last week. We missed you being there to argue in favor of that theory and to argue (separately) for the validity of the test results at Eagleworks. Several experts on Quantum Mechanics were there: Prof. John Cramer (author of the excellent book "The Quantum Handshake" which I highly recommend: https://www.amazon.com/Quantum-Handshake-Entanglement-Nonlocality-Transactions/dp/3319246402/ref=sr_1_1?ie=UTF8&qid=1510085833&sr=8-1&keywords=the+quantum+handshake and Prof. Ray Chiao of Berkeley (now at Merced).
One must say that if this theory by White, that the Quantum Vacuum gives chaotic forces in all directions, would apply, it looks like the center of mass will not get accelerated in any well-defined direction when placed in Space (if the forces balance each other over suitable periods of time). Let's say that they don't balance in the orthogonal directions.
Also, if you have a force perpendicular to the longitudinal axis as well as a longitudinal force, it looks like the EM Drive would not travel parallel to the longitudinal axis.
But let's get to experimental facts, instead of discussing controversial theories. There are more theories than physicists, and in the end what matters are experimental results.
Did NASA Eagleworks ever place the EM Drive with the longitudinal axis parallel to the arms of the torsional pendulum and measured a force perpendicular to the pendulum's arms?
Did Eagleworks also measure a force in this direction?
Thanks
There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it.
Also, just FYI: The difference between my QV model of gravity and Dr. Whites Q-thruster theory, is that I do not require electron-positron pairs. I only require the EM field in free space. IMO and as I see it, despite Heisenberg, electron-positron pairs can only be created where there is matter present to provide a sufficiently strong EM field above the Schwinger limit. Such as, the field in the immediate vicinity of an electron or charged ion. In free space, I expect that they are few and far between.
It is the presence of the e-p pairs, their numbers and life-times, that lead to Dr's. Fearn and Woodward's refutation of Dr. Whites theory in the JBIS article published earlier this year; (Vol. 69, No. 9/10, Sept./Oct. 2016). In my model, this refutation would not apply.
What I'm working on is to determine is how to relate momentum exchange to gravito-magnetic flux being emitted from the frustum, using a gravito-magnetic gauge field. And, how to generate it.
Electron-positron synthesis in thunderstorms. Pretty much "free space", and old news:
https://www.nasa.gov/mission_pages/GLAST/news/fermi-thunderstorms.html
I don't think any resonant cavity yet contructed, anywhere, has a Q sufficient to yield a field strength at or above the Schwinger limit. -
#2648 by flux_capacitor on 08 Nov, 2017 00:32
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{…}
Now my hunch is that this generates a mass fluctuation giving rise to a Mach effect as the can interacts with universal gravitation in order to preserve Noether's theorum (translation, it has to move and it has to interact with an external field to do so).
Rather than a relation to Mach effects, your developments make me think about Shawyer's controversial claim:Quote from: Roger ShawyerThe inevitable objection raised, is that the apparently closed system produced by this arrangement cannot result in an output force, but will merely produce strain within the waveguide walls. However, this ignores Einstein’s Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light. Thus the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separate frames of reference.
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#2649 by Bob Woods on 08 Nov, 2017 01:37
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You know, just when this thread get slow, it always gets VERY interesting again.
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#2650 by Monomorphic on 08 Nov, 2017 10:30
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TU Dresden reported achieving Q from 40,000 to 500,000
I would be very interested in how this Q was measured. What VNA was used? We are trying to track down a copy of Tajmar's presentation now.
The US Navy reported a Q factor of 16,500 at 1.9GHz. I've never been able to get a Q factor of more than 40,000 in simulations using nearly perfect geometry.
I'm a little skeptical that Tajmar's team was able to go from a cavity with a Q factor of 20 to one better than everyone else, including the US Navy. -
#2651 by Rodal on 08 Nov, 2017 12:27
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<<I would be very interested in how this Q was measured.>>TU Dresden reported achieving Q from 40,000 to 500,000
I would be very interested in how this Q was measured. What VNA was used? We are trying to track down a copy of Tajmar's presentation now.
The US Navy reported a Q factor of 16,500 at 1.9GHz. I've never been able to get a Q factor of more than 40,000 in simulations using nearly perfect geometry.
I'm a little skeptical that Tajmar's team was able to go from a cavity with a Q factor of 20 to one better than everyone else, including the US Navy.
My recollection is that it was measured from the amplitude vs frequency response using an analyzer (−3 dB at a voltage gain of 0.707 or half-power bandwidth). I did not inquire further as I was interested in other things. Now it is not as straightforward to do as when one has a chance to be face to face with four (4) people from TU Dresden that can give you tons of information. Imagine that: it was not just Tajmar who was there, but 3 of his Ph.D. students as well. A unique opportunity. They were all very open to talk and exchange information. When you want information there is nothing better than face to face interaction. Face to face interaction is infinitely better than reading reports, as you can ask all kinds of details that may not appear in reports.
To get a higher loaded Q from experimental measurements, pay attention to the coupling factor!
Match the load to the power source.
Concerning your numerical simulations compare with an exact solution, and perform a convergence study of your numerical model by varyiing the number of nodes.
Concerning <<better than everyone else, including the US Navy.>> that is mixing different things.
Q is highly dependent on mode shape. My understanding (according to my recollection) is that TU Dresden aimed for mode shapes TE01p which produce highest Q, while my understanding (according to my recollection) is that the US Navy Research Lab aimed for TM212 like NASA Eagleworks that has lower Q (as one can show analytically). Also, my understanding (according to my recollection) is that the US Navy RL is going to test with dielectrics, dielectrics have lower Q.
Finally, my understanding (according to my recollection) is that TU Dresden had a program to measure with spherical plates as well as flat ends, while US Navy RL only used flat ends, like NASA Eagleworks.
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#2652 by Peter Lauwer on 08 Nov, 2017 12:44
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There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it.
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I also have the input at the centre of the small endplate [1]. I haven't figured out, though, 'where to leave the dielectric plate'. On the small endplate with a hole in it?
Btw, can any of you tell whether Tajmar used dielectrics in any of his recent experiments?
Thanks, Peter.
[1] like the new one, made of semi rigid cable (RG402), placed off-centre (so the centre of the loop is in the centre, of course). Inner diam = 10 mm, distance from endplate is 15 mm (the RG402 inner conductor is diam 0.9 mm). I hope to compare this loop with the 'Zhang et al. 3-fold loop', about which I posted earlier, with a network analyser (soon). The endplate needs to be polished first, though.
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#2653 by TheTraveller on 08 Nov, 2017 12:54
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To get a higher loaded Q from experimental measurements, pay attention to the coupling factor!TU Dresden reported achieving Q from 40,000 to 500,000
I would be very interested in how this Q was measured. What VNA was used? We are trying to track down a copy of Tajmar's presentation now.
The US Navy reported a Q factor of 16,500 at 1.9GHz. I've never been able to get a Q factor of more than 40,000 in simulations using nearly perfect geometry.
I'm a little skeptical that Tajmar's team was able to go from a cavity with a Q factor of 20 to one better than everyone else, including the US Navy.
Match the load to the power source.
Concerning your numerical simulations compare with an exact solution, and perform a convergence study of your numerical model by varyiing the number of nodes.
Hi Jose,
You beat me to the coupling factor. Very important. Then mode. TE01x generates the highest Q. Plus POLISH, end plate parallelism, both end plates at right angle to the frustum axis, build geometry to better than +-10 um. Q is also highly geometry related, ie better to have bigger big end dia than longer frustum length. -
#2654 by Rodal on 08 Nov, 2017 12:56
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...can any of you tell whether Tajmar used dielectrics in any of his recent experiments?
NO!
Thanks, Peter. ...
My understanding (according to my recollection) is that NO dielectrics used in the experiments by TU Dresden reported at the workshop last week.
In contrast, my understanding (according to my recollection) is that the US Navy Research Lab reported that they plan to use dielectric inserts, as their program is to reproduce NASA Eagleworks tests. Please recall that dielectric inserts lower the Q, due to the losses (tandelta) of the dielectric. -
#2655 by TheTraveller on 08 Nov, 2017 12:59
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There is one point that hasn't been mentioned. The Eagleworks frustum and the one at TU Dresden both have the MW coax cable and antenna on the "side". Unless the input port is oriented "Up" or "Down", I would not rule out that the input antenna contributes a significant amount of thrust. This is why I encouraged Jamie and anyone, to put the input at one end or the other. Not only is it better for exciting symmetrical TE modes, it also keeps the input momentum in line with the expected thrust vector, not orthogonal to it.
...
I also have the input at the centre of the small endplate [1]. I haven't figured out, though, 'where to leave the dielectric plate'. On the small endplate with a hole in it?
Btw, can any of you tell whether Tajmar used dielectrics in any of his recent experiments?
Thanks, Peter.
[1] like the new one, made of semi rigid cable (RG402), placed off-centre (so the centre of the loop is in the centre, of course). Inner diam = 10 mm, distance from endplate is 15 mm (the RG402 inner conductor is diam 0.9 mm). I hope to compare this loop with the 'Zhang et al. 3-fold loop', about which I posted earlier, with a network analyser (soon). The endplate needs to be polished first, though.
Hi Peter,
Forget the dielectric. Total waste of time, effort and money.
EW results:
Small end dielectric: 1.2mN/kW
Big end dielectric: 2.0mN/kW
NO dielectric: 3.9mN/kW
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#2656 by tleach on 08 Nov, 2017 13:36
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If the mass and energy of the frustum (and indeed of the universe itself) is just information, then by gosh, all we're trying to do is move around a bunch (a WHOLE bunch) of 1s and 0s.
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No, it's not. The universe is a quantum computer, not a binary one.
'-)
Peter
Lol! Well, I guess we'll have to keep all those 1s and 0s in superposition while we move 'em! That would make thinga a little more difficult... -
#2657 by Mulletron on 08 Nov, 2017 14:01
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TU Dresden reported achieving Q from 40,000 to 500,000
I would be very interested in how this Q was measured. What VNA was used? We are trying to track down a copy of Tajmar's presentation now.
The US Navy reported a Q factor of 16,500 at 1.9GHz. I've never been able to get a Q factor of more than 40,000 in simulations using nearly perfect geometry.
I'm a little skeptical that Tajmar's team was able to go from a cavity with a Q factor of 20 to one better than everyone else, including the US Navy.
What is the source of this image and other data? All I have found about this is from here:
http://forum.nasaspaceflight.com/index.php?topic=42978.msg1719490#msg1719490 -
#2658 by Rodal on 08 Nov, 2017 14:05
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If this is from an unpublished report: before posting images or actual data or actual text from unpublished reports please check whether the copyrights and permissions allow it. We can discuss what we recall hearing at a public presentation, which is different from posting images of the presentation, or posting the presentation itself (because our recollection, memory and understanding are imperfect and subjective). To post images or the presentation itself one needs permission from the author.
What is the source of this image and other data? All I have found about this is from here:
http://forum.nasaspaceflight.com/index.php?topic=42978.msg1719490#msg1719490
My understanding is that ssi.org has the correct agreements with the presenters and that some of the presentations and some of the videos (the presentations where the author gave the permission to post video, images and text) will be at the SSI.ORG website within a few weeks. -
#2659 by TheTraveller on 08 Nov, 2017 14:52
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There are 2 very major difference in EmDrive torsion arm test rigs.
1) allowing sufficient background external forces, vibration, that will generate enough initial small end forward acceleration to trigger the self sustaining Motor mode
2) uN/um sensitivy which defines displacement available to support free acceleration before the torsion wire generates enough back force/torque to stop acceleration and when acceleration stops, thrust generation stops. .
As example the
1) EW test rig rates at 24uN/um
2) Jamie's test rig 0.18uN/um
Which says the EW torsion test rig is 133 times stiffer than Jamie's test rig. Being tighter means for the same thrust, the EmDrive would have 133x LESS displacement/movenent to self accelerate and get solidly into Motor mode.
I believe Dave's test rig was looser than Jamie's as his test rig arms were longer. Maybe Dave will provide the uN/um sensitivity for his test rig?
Jamie's measured 3.5uN is equilivant to 19.4um of free to accelerate displacement.
I suggest 20um is a good number for experimenters to design their torsion rigs to support and don't isolate all the external forces or there will be no thrust generated.
Which says an EmDrive torsion test rig needs to be designed to be EmDrive thrust generation friendly.
