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#200
by
Rodal
on 15 Dec, 2015 14:06
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Worth a read...mr li is a poster here but forgot nick: http://arxiv.org/abs/1510.07752
Was that (Li) the paper that motivated a short-lived return by Paul March (NASA) to these threads? If that is the case, did Paul March address the paper vis-a-vis the NASA experiments in his short-lived return to these NASA threads?
(I was not active in these threads at the time of those exchanges.)
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#201
by
rfmwguy
on 15 Dec, 2015 14:07
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Would you agree that the Li's paper positing lorentz force describing a torsional (rotary) force of up to a few micronewtons is irrelevant for horizontal beam measurements?
rfmwgy, I appreciate your doing your own experiment. I read NFS occasionally, and happen to see your question when I am having a sick leave today. Actually our paper (the Li's paper) had shown Lorentz force up to 41 micro-Newtons (see fig 4 of the paper), and that was with the NASA style second generation damper. If we use NASA's first generation damper, that number can be easily doubled or even tripled. Yes, I believe all NASA saw in their 2014 paper were Lorentz force. The ball is now in NASA's court. They need to address this issue in their next paper. Are there ways to eliminate/control for Lorentz force in an experiment? Yes, there are, but they missed that in their 2014 paper.
There you are! Sorry mr li, bad memory. For us horizontal balance beam types, were wondering if you measured any non- torsional or y axis lorentz forces? - dave
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#202
by
rfmwguy
on 15 Dec, 2015 14:09
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Worth a read...mr li is a poster here but forgot nick: http://arxiv.org/abs/1510.07752
Was that (Li) the paper that motivated a short-lived return by Paul March (NASA) to these threads? If that is the case, did Paul March address the paper vis-a-vis the NASA experiments in his short-lived return to these NASA threads?
(I was not active in these threads at the time of those exchanges.)
Yes, and mr li would be best to comment on pauls response...it was a very interesting topic.
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#203
by
rfmwguy
on 15 Dec, 2015 14:19
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#204
by
Tellmeagain
on 15 Dec, 2015 14:21
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Would you agree that the Li's paper positing lorentz force describing a torsional (rotary) force of up to a few micronewtons is irrelevant for horizontal beam measurements?
rfmwgy, I appreciate your doing your own experiment. I read NFS occasionally, and happen to see your question when I am having a sick leave today. Actually our paper (the Li's paper) had shown Lorentz force up to 41 micro-Newtons (see fig 4 of the paper), and that was with the NASA style second generation damper. If we use NASA's first generation damper, that number can be easily doubled or even tripled. Yes, I believe all NASA saw in their 2014 paper were Lorentz force. The ball is now in NASA's court. They need to address this issue in their next paper. Are there ways to eliminate/control for Lorentz force in an experiment? Yes, there are, but they missed that in their 2014 paper.
There you are! Sorry mr li, bad memory. For us horizontal balance beam types, were wondering if you measured any non- torsional or y axis lorentz forces? - dave
We didn't measure the Lorentz force on the y axis (meaning vertical?). This is because the current loops in our experiment were vertical, so the Lorentz forces we saw would be confined in the horizontal direction. Remember that The Lorentz force is perpendicular both to the magnet field and to the current.
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#205
by
Rodal
on 15 Dec, 2015 14:30
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Doc, here is pauls reply from T5:
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
Seems they've moved to a balance beam
Oh, I see. Has Li answered and addressed the following statement by Paul March ? (Bold added for emphasis)
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.
that seems to be in conflict (again I was not active in the thread at that time, so I am not clearly following this) with this latest statement (
are Li and Paul March referring to the same "2nd generation" damper when Li states "that was with the NASA style second generation damper" ?):
Would you agree that the Li's paper positing lorentz force describing a torsional (rotary) force of up to a few micronewtons is irrelevant for horizontal beam measurements?
rfmwgy, I appreciate your doing your own experiment. I read NFS occasionally, and happen to see your question when I am having a sick leave today. Actually our paper (the Li's paper) had shown Lorentz force up to 41 micro-Newtons (see fig 4 of the paper), and that was with the NASA style second generation damper. If we use NASA's first generation damper, that number can be easily doubled or even tripled. Yes, I believe all NASA saw in their 2014 paper were Lorentz force. The ball is now in NASA's court. They need to address this issue in their next paper. Are there ways to eliminate/control for Lorentz force in an experiment? Yes, there are, but they missed that in their 2014 paper.
(Bold added for emphasis)
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#206
by
Tellmeagain
on 15 Dec, 2015 14:35
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#207
by
Rodal
on 15 Dec, 2015 14:38
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#208
by
Tellmeagain
on 15 Dec, 2015 14:43
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Doc, here is pauls reply from T5:
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1440938#msg1440938
Seems they've moved to a balance beam
Oh, I see. Has Li answered and addressed the following statement by Paul March ? (Bold added for emphasis)
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.
that seems to contradict this latest statement (are Li and Paul March referring to the same "2nd generation" damper when Li states "that was with the NASA style second generation damper" ?):
Would you agree that the Li's paper positing lorentz force describing a torsional (rotary) force of up to a few micronewtons is irrelevant for horizontal beam measurements?
rfmwgy, I appreciate your doing your own experiment. I read NFS occasionally, and happen to see your question when I am having a sick leave today. Actually our paper (the Li's paper) had shown Lorentz force up to 41 micro-Newtons (see fig 4 of the paper), and that was with the NASA style second generation damper. If we use NASA's first generation damper, that number can be easily doubled or even tripled. Yes, I believe all NASA saw in their 2014 paper were Lorentz force. The ball is now in NASA's court. They need to address this issue in their next paper. Are there ways to eliminate/control for Lorentz force in an experiment? Yes, there are, but they missed that in their 2014 paper.
(Bold added for emphasis)
I didn't comment on Paul's statement. Yes we mimicked their second generation damper, but it was not emphasized enough in the paper. It is shown in fig 1 of our paper, where the damper is enclosed. We also have photos in supplemental materials, which is available with request. I attach them here so you can see that we used the closed face magnet damper. As it always happens, nothing is perfect in engineering, so there is still leaked magnetic field, as we have shown in the first two attached photos.
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#209
by
Tellmeagain
on 15 Dec, 2015 14:48
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I didn't comment on Paul's statement. Yes we mimicked their second generation damper, but it was not emphasized enough in the paper. It is shown in fig 1 of our paper, where the damper is enclosed. We also have photos in supplemental materials, which is available with request. I attach them here so you can see that we used the closed face magnet damper. As it always happens, nothing is perfect in engineering, so there is still leaked magnetic field, as we have shown in the first two attached photos.
It was not very different from NASA's second generation damper, seen at
http://nextbigfuture.com/2014/09/paul-march-is-providing-more.html
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#210
by
Rodal
on 15 Dec, 2015 15:04
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I didn't comment on Paul's statement. Yes we mimicked their second generation damper, but it was not emphasized enough in the paper. It is shown in fig 1 of our paper, where the damper is enclosed. We also have photos in supplemental materials, which is available with request. I attach them here so you can see that we used the closed face magnet damper. As it always happens, nothing is perfect in engineering, so there is still leaked magnetic field, as we have shown in the first two attached photos.
It was not very different from NASA's second generation damper, seen at
http://nextbigfuture.com/2014/09/paul-march-is-providing-more.html
In early threads, I advocated the use of a simple oil damper (as used in classical physics experiments to measure gravitational forces a long time ago) instead of any magnetic damper.
Brito Marini and Galian (and later on Marini and Galian) nullified the claims of propellant-less thrust from a Mach-Lorentz Woodward effect thruster using a simple pendulum with the thruster all self-contained and using oil damping:
http://arc.aiaa.org/doi/abs/10.2514/6.2009-5070 http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpphttps://www.researchgate.net/profile/Ricardo_Marini
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#211
by
Tellmeagain
on 15 Dec, 2015 15:18
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I now comment on Paul's other statements. He said:
"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."
I need to see their next paper to comment on their new grounding scheme. However, the 2 uN dummy load test could not imply a successful grounding scheme. Remember that their dummy load was not grounded to the beam (see our paper for this point). If their frustum was grounded to the beam, then the dummy load test and frustum test were with different DC distribution.
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#212
by
Tellmeagain
on 15 Dec, 2015 15:26
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In early threads, I advocated the use of a simple oil damper (as used in classical physics experiments to measure gravitational forces a long time ago) instead of any magnetic damper.
Brito Marini and Galian (and later on Marini and Galian) nullified the claims of propellant-less thrust from a Mach-Lorentz Woodward effect thruster using a simple pendulum with the thruster all self-contained and using oil damping:
http://arc.aiaa.org/doi/abs/10.2514/6.2009-5070
http://arc.aiaa.org/doi/abs/10.2514/1.46541?journalCode=jpp
https://www.researchgate.net/profile/Ricardo_Marini
Good points. NASA should try the oil damper, as Tajmar did. They should also rotate their test bed and measure thrusts with different directions relative to the earth magnetic field. A better grounding scheme ,such as the star grounding scheme see-shell mentioned, will help. With that, the grounding of the frustum should be only through the shield of the RF cable.
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#213
by
rfmwguy
on 15 Dec, 2015 15:31
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Now, this is just weird...a vna sweep of an unmodified baritone bell...36dB return loss(!) centering about 2.14 GHz. Simple copper board clamped on end, no other modifications, mag antenna probe I've been usin for NSF-1701 sweeps.
Will try closing off narrow end and see where it tunes up in frequency. Can I tune it to 2.45 GHz? Maybe...
1st tune (steel wool in bore - don't be a hater) resulted in 2.74 GHz resonance and 20dB RL. Yep, I can tune it.
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#214
by
Rodal
on 15 Dec, 2015 16:15
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Now, this is just weird...a vna sweep of an unmodified baritone bell...36dB return loss(!) centering about 2.14 GHz. Simple copper board clamped on end, no other modifications, mag antenna probe I've been usin for NSF-1701 sweeps.
Will try closing off narrow end and see where it tunes up in frequency. Can I tune it to 2.45 GHz? Maybe...
1st tune (steel wool in bore - don't be a hater) resulted in 2.74 GHz resonance and 20dB RL. Yep, I can tune it.
This is a Do-It-Yourself-at-home
experimental confirmation by RFMWGUY of what I have been stating for a long time in these threads:
that Shawyer's claim that there is a cut-off frequency for electromagnetic cavity resonance is incorrect (as was already known from undergraduate textbooks).
It is easy to show that the small throat end of the tested wind instrument has a dimension smaller than corresponding to the so-called cut-off frequency.
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#215
by
OnlyMe
on 15 Dec, 2015 16:32
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Now, this is just weird...a vna sweep of an unmodified baritone bell...36dB return loss(!) centering about 2.14 GHz. Simple copper board clamped on end, no other modifications, mag antenna probe I've been usin for NSF-1701 sweeps.
Will try closing off narrow end and see where it tunes up in frequency. Can I tune it to 2.45 GHz? Maybe...
1st tune (steel wool in bore - don't be a hater) resulted in 2.74 GHz resonance and 20dB RL. Yep, I can tune it.
This is a Do-It-Yourself-at-home experimental confirmation by RFMWGUY of what I have been stating for a long time in these threads: that Shawyer's claim that there is a cut-off frequency for electromagnetic cavity resonance is incorrect (as was already known from undergraduate textbooks).
It is easy to show that the small throat end of the tested wind instrument has a dimension much smaller than corresponding to the so-called cut-off frequency.
I believe the only way this is applicable to Shawyer's cutoff statement is if you begin with the assumption that there is no thrust. His statement seems tied to a cutoff frequency associated with generating thrust.
Separately...
Something that might be interesting is if rfmwguy were to rerun the initial test (without the steel wool) and instead of closing the mouth piece end with a plate, terminate it into a faraday cage with ground isolated from the baritone. Maybe even try to set up some means of determining if any microwaves in the range produced by the magnetron even escape through the mouth piece end. The diameter and geometry of the instrument may wind up grounding out all microwaves before they reach a open mouth piece. This would experimentally confirm the last comment above.
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#216
by
CraigPichach
on 15 Dec, 2015 16:36
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An update on our 100kW test project. Model using HFSS using eigenmode solver, TE013 mode 914.85MHz Q=133526. Loop coupled design for ease of build, cost and stress concerns.
As we are planning to use a high power coax line and are designing as a pressure vessel, one recommendation is to use copper cladded stainless steel... does anyone see any objections to the use of this material so long as we clad the internals with copper? This would help us with vessel integrity and cooling; while I do think we will achieve resonance is there any EM-Drive Q thruster theories that say not to do this (i.e. impacting the quantum vacuum??).
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#217
by
Rodal
on 15 Dec, 2015 16:37
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Now, this is just weird...a vna sweep of an unmodified baritone bell...36dB return loss(!) centering about 2.14 GHz. Simple copper board clamped on end, no other modifications, mag antenna probe I've been usin for NSF-1701 sweeps.
Will try closing off narrow end and see where it tunes up in frequency. Can I tune it to 2.45 GHz? Maybe...
1st tune (steel wool in bore - don't be a hater) resulted in 2.74 GHz resonance and 20dB RL. Yep, I can tune it.
This is a Do-It-Yourself-at-home experimental confirmation by RFMWGUY of what I have been stating for a long time in these threads: that Shawyer's claim that there is a cut-off frequency for electromagnetic cavity resonance is incorrect (as was already known from undergraduate textbooks).
It is easy to show that the small throat end of the tested wind instrument has a dimension much smaller than corresponding to the so-called cut-off frequency.
I believe the only way this is applicable to Shawyer's cutoff statement is if you begin with the assumption that there is no thrust. His statement seems tied to a cutoff frequency associated with generating thrust.
Separately...
Something that might be interesting is if rfmwguy were to rerun the initial test (without the steel wool) and instead of closing the mouth piece end with a plate, terminate it into a faraday cage with ground isolated from the baritone. Maybe even try to set up some means of determining if any microwaves in the range produced by the magnetron even escape through the mouth piece end. The diameter and geometry of the instrument may wind up grounding out all microwaves before they reach a open mouth piece. This would experimentally confirm the last comment above.
There is no statement in Shaywer's papers (that I have seen) stating that his cut-off equations are only applicable to anomalous thrust effects. Shawyer makes the statements about cut-off frequency without any such "thrust dependence" justification in his papers. Actually, Shawyer conflates open waveguides and resonating cavities in his papers and presents his equations (including quoting Prof. Cullen's Ph.D. thesis out of context for a resonating cavity) without such modifiers in his papers.
If anyone is to interpret Shawyer's equations (including his strange special relativity modifications) as only applicable to thrust, such "thrust dependent" constraint on special relativity and "thrust dependent" constraint on resonance should be proven (or at least discussed) by Shawyer, rather than assumed ab ibnitio by the reader of his papers.
There is no explanation as to why resonance above cut-off would result in anomalous thrust while resonance below cut-off would result in no thrust. Shawyer does not even state that his cut-off equations are only applicable to anomalous thrust effects.
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#218
by
Rodal
on 15 Dec, 2015 16:39
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An update on our 100kW test project. Model using HFSS using eigenmode solver, TE013 mode 914.85MHz Q=133526. Loop coupled design for ease of build, cost and stress concerns.
As we are planning to use a high power coax line and are designing as a pressure vessel, one recommendation is to use copper cladded stainless steel... does anyone see any objections to the use of this material so long as we clad the internals with copper? This would help us with vessel integrity and cooling; while I do think we will achieve resonance is there any EM-Drive Q thruster theories that say not to do this (i.e. impacting the quantum vacuum??).
It is noteworthy to remark that this is the ONLY test by anyone (as far as I know) where there is a deliberate attempt to test for anomalous thrust forces that are way beyond the forces produced by thermal effects.
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#219
by
Tellmeagain
on 15 Dec, 2015 16:49
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An update on our 100kW test project. Model using HFSS using eigenmode solver, TE013 mode 914.85MHz Q=133526. Loop coupled design for ease of build, cost and stress concerns.
As we are planning to use a high power coax line and are designing as a pressure vessel, one recommendation is to use copper cladded stainless steel... does anyone see any objections to the use of this material so long as we clad the internals with copper? This would help us with vessel integrity and cooling; while I do think we will achieve resonance is there any EM-Drive Q thruster theories that say not to do this (i.e. impacting the quantum vacuum??).
It is noteworthy to remark that this is the ONLY test by anyone (as far as I know) where there is a deliberate attempt to test for anomalous thrust forces that are way beyond the forces produced by thermal effects.
Assuming the frustum is resonating with 100KW input, won't we see 100KW of heat generated by the furstum? If we see 100W heat only, we can only assume that 99.9% power are reflected back and this test is no better than a 100W test.