Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2099538 times)

Online Galactic Penguin SST

It appears my previous post got deleted.

So I'll ask again. Has this psudoscience nonsense been found to be false yet? Have any proper scientists tested this contraption so that they can show that it doesn't work?

I'm sure some "proper scientists" will come round for a look eventually. In the meantime, history has a lot to teach us about these sorts of things:

http://amasci.com/weird/vindac.html
http://www.lifehack.org/articles/lifestyle/6-world-changing-ideas-that-were-originally-rejected.html
http://www.cracked.com/article_18822_5-famous-scientists-dismissed-as-morons-in-their-time.html

Every previous world changing idea didn't try to violate a founding principal of all physics, namely CoE and CoM.

Quote
Quote
...so that they can show that it doesn't work

Just curious, what makes you so certain that it doesn't work? I mean, I have no idea if it works or not. The only certain thing I know here is that I don't know for certain if it works or doesn't.

There is a growing body of evidence which suggest that it does work. It hasn't been proven by anybody that it doesn't work.

I'm still waiting for an actual test of the operation of this craft. There haven't been any non-faulty experiments done yet that actually show it producing any thrust. Namely it must be tested in a vacuum. I don't try to merge philosophy and science and currently this "EM Drive" is purely in the realm of philosophy with no actual data yet. Thus I dismiss it just like the people claiming they made an anti-gravity drive in their garage.

It's rather insulting that this forum topic even exists here.

The main thing is that these guys here are completely skeptical of the original "theory" and are trying to do their own experiments - from what I read here it seems that they were skeptical of the "experimental results" as well but they want to do an independent experiment as well to settle the case, whether there is some effect that could be used in spaceflight or, if I read correctly, more probably if there is some other thing in action that cannot be used as a thruster.

At least, that is what I understand from my own undergraduate level physics anyway (some of the math is beyond my level, but at least I knew what a Bessel function is  ;)). So I don't see why such a thread here is "insulting" as long as those guys aren't hopping to a conclusion that this "EM drive" works with completely wrong physics explanations?

Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline Mulletron

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It appears my previous post got deleted.

So I'll ask again. Has this psudoscience nonsense been found to be false yet? Have any proper scientists tested this contraption so that they can show that it doesn't work?

I'm sure some "proper scientists" will come round for a look eventually. In the meantime, history has a lot to teach us about these sorts of things:

http://amasci.com/weird/vindac.html
http://www.lifehack.org/articles/lifestyle/6-world-changing-ideas-that-were-originally-rejected.html
http://www.cracked.com/article_18822_5-famous-scientists-dismissed-as-morons-in-their-time.html

Every previous world changing idea didn't try to violate a founding principal of all physics, namely CoE and CoM.

Quote
Quote
...so that they can show that it doesn't work

Just curious, what makes you so certain that it doesn't work? I mean, I have no idea if it works or not. The only certain thing I know here is that I don't know for certain if it works or doesn't.

There is a growing body of evidence which suggest that it does work. It hasn't been proven by anybody that it doesn't work.

I'm still waiting for an actual test of the operation of this craft. There haven't been any non-faulty experiments done yet that actually show it producing any thrust. Namely it must be tested in a vacuum. I don't try to merge philosophy and science and currently this "EM Drive" is purely in the realm of philosophy with no actual data yet. Thus I dismiss it just like the people claiming they made an anti-gravity drive in their garage.

It's rather insulting that this forum topic even exists here.

Well I can't fault you for being skeptical, but I do urge you to review the pages of this thread. Things start getting rather interesting around page 20 or so. Many of your concerns have been addressed here, such as the vacuum testing, which has been completed with data provided, and reported here by an engineer at Eagleworks.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1326608#msg1326608

Also interesting:
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1333835#msg1333835

And, in my humble opinion, there has been plenty of existing, published in reputable journals...science uncovered, which can shed light on how the EMdrive can thrust, without violating any conservation laws.
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1330846#msg1330846
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1333392#msg1333392

Also @Notsosureofit has developed his own very plausible ideas about how EMdrive can thrust, using good old established science. @Rodal, @Aero, and @Frobnicat have all provided exhaustive data and calculations both for and against the reports of measured thrust at Eagleworks and NWPU China.

We're openly hostile to pseudoscience here, but at the same time, we must be mindful that in order to get to the bottom of this mystery, we have to be willing to step outside of our comfort zones.

From a practical standpoint, I find it extremely unlikely that the only means mankind will ever have to propel spacecraft through the vacuum, is to carry along stores of fuel and shoot propellant out the back side.

If EMdrives aren't the answer, the lessons learned from this may lead to the answer. Once field propulsion is a reality, we can consider the solar system to be unlocked.

Now that is worth a look.
« Last Edit: 04/04/2015 04:52 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Star One

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Also how many times in the history of science have things been declared to be nonsense by the majority only later turning out to be correct and the status quo wrong.

By the way aren't Eagleworks approaching the end of the period of time when they have to produce the results for this party testing?

« Last Edit: 04/04/2015 05:17 PM by Star One »

Online MichaelBlackbourn

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Great post Mulletron about the why of doing this.

I'm hopeful something like EMdrive or WoodwardME ends up being possible.

Both are a little like the Polywell, 10-20 million and you could settle the issue conclusively. The payoff on any of these if they come up legit would be immense. Even better if you can pair a polywell with an EMdrive.... Then we're in business with just a pocket full of boron and hydrogen.

I wonder what the math is on pushing a 3m polywell chamber with pb+j He conversion equipment and an EMdrive... Wait, maybe you could just bypass the EMdrive with a polywell and just fire the He out one side... Hmm. Either way... We need to investigate these possibilities... The rocket equation is too brutal.

Offline Star One

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Problem is no one is going to give that kind of money unless they are proved to work at the level they are now.

Online MichaelBlackbourn

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Problem is no one is going to give that kind of money unless they are proved to work at the level they are now.

I would guess that if not now, then in 10-15 years someone like spacex might get into a bit more speculative research once they have their mars plans in action. Let's hope.

Offline Notsosureofit

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FYI

Still fussing in short bursts to find an integral version of the dispersion speculation.


@RODAL

One thing that seems to keep coming through is that the step change of dielectric in the mid-waveguide (cylindrical) case has twice the thrust of a linear change, all else being equal.

Got to run but more on this later.


Online Rodal

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You accurately and completely answered the questions I asked.  Unfortunately, I didn't ask my questions very well.  :)

http://forum.nasaspaceflight.com/index.php?topic=36313.msg1354235#msg1354235

A constant-amplitude standing wave does indeed result in a zero time-average Poynting vector.  However, I am questioning your conclusion that a constant-amplitude standing wave accurately represents a real resonator cavity such as the as-tested EM drive frustum.  Instead, I would expect a decaying amplitude standing wave to be a more accurate model/plot (as would be derived from a full solution to Maxwell's equations with proper boundary conditions such as non-zero resistance, etc).

Once a time-decaying standing wave is used for computation of a time-average Poynting vector, I'm having trouble seeing how the incident and reflected energy can perfectly cancel and become zero.  I'll readily admit I may be oversimplifying and/or missing a fundamental concept;  it's been a long time since I actually computed time constants for resonant cavities using Maxwell's equations and non-zero resistances.

Phrased a bit differently, I believe only excited modes with current/thermal losses in the base plates will significantly weight the direction of the time-average Poynting vector.  Each pair of incident/reflected waves would have a larger energy loss at the base plate with the excited E field (and therefore excited currents) than the energy loss at the opposing base plate.  For modes with near-zero E fields at the base plate boundaries, each incident/reflected wave pair would have a near equal energy delta regardless of which base plate they came in contact with;  the resulting time-averaged direction would be random and magnitude limited by the energy lost in the very first reflection (randomly either the large or small base, with a magnitude very close to zero).

I view this Poynting vector discussion to be completely independent of whether Dr. White's QV interactions, or some other classical physics can explain the EM drive anomalous thrust.  Just wanted to chime in on a what appeared to be the use of a constant-amplitude standing wave to describe a real-world system.  Your earlier observation of a non-zero time averaged Poynting vector seemed like a reasonable statement given that only excited modes with current/thermal losses in the base plates would quickly diverge from the simplified constant-amplitude standing wave model. 

Regards,
James
James, thank you for the interesting, thought-provoking discussion.  :)

Let's calculate some numbers to estimate what we are discussing.

The electromagnetic fields transition from the air or vacuum medium (where they are out of phase by 90 degrees) to the copper over an extremely small distance: a boundary layer. The skin depth for copper at 2 GHz is 1.48 micrometers = 58.2 microinches .  When showing the Poynting vector field distribution this distance is infinitesimal compared to the rest of the cavity.  In this very small distance inside the copper (1.48 micrometers ) the electromagnetic fields in the copper are out of phase by approximately 45 degrees (due to the high conductivity of copper).  For a transverse magnetic (TM) mode, the only electromagnetic field component that is continuous across the vacuum/copper interface is the electric field component tangent to the copper surface.

More interestingly (for this thread's discussion due to the significance that the NASA experimenters have placed on the dielectric being responsible for providing the measured thrust) is what happens in the High Density PolyEthylene (HDPE) dielectric polymer insert.  Because the dimensions of the dielectric are not negligible compared to the EM Drive's dimension, and the dielectric is not modeled as just a boundary condition.

The loss tangent of HDPE is reported to be

tan delta = 0.0004

Therefore the intrinsic impedance angle is

intrinsic impedance angle =(ArcTan[0.0004])/2

Therefore, inside the HDPE dielectric the electric and magnetic fields, instead of being out of phase by 90 degrees (as they are in the air or vacuum medium), will be out of phase by:

90 - (180/Pi) (ArcTan[0.0004])/2 = 89.98854084470854

This phase angle (89.9885 degrees)  will show practically no visual difference with 90 degrees at the resolution of the following image :



The Poynting vector inside the HDPE dielectric, instead of having a zero time average, will have the following factor multiplying ExB/mu :

Cos[(Pi/180) (90 - (180/Pi) (ArcTan[0.0004])/2)]/2= 0.00009999999400006368

So, inside the HDPE polymer dielectric the Poynting vector has this small magnitude over a period (or multiples thereof).

So, the extent of this approximation, for the HDPE dielectric is about 0.01 % (which is negligible in comparison to several other approximations).


Now, let's examine what this (very small intensity Poynting vector time average) means, concerning the discussion in this EM Drive.

If one were to posit that the EM Drive's thrust is due to the very small magnitude of the time average of the Poynting vector due to these thermal losses (in the HDPE dielectric or in the copper):

1) It would mean that there should be more thrust with lower Q.  This is the complete opposite of what the experimenters like Shawyer claims (Shawyer claims that the higher the Q, the greater the thrust).  Notice that

Tan [loss angle] = Tan[ 2 impedance angle ]= 1/Q

2) All the equations proposed so far (by Shawyer, McCulloch and @Notsosureofit) have predicted thrust proportional to Q.  This is the complete opposite of what such a Poynting vector would predict (it would predict thrust proportional to 1/Q instead), because

Tan delta= 1/Q

measured Q        effective tan delta

7320                  1.366* 10 ^(-4)
22000                4.545* 10 ^(-5)
10^6                  10^(-7)

3) It would mean that experimenters like Shawyer and Fetta are in the completely wrong track pursuing superconducting EM Drives, as superconducting EM Drives would lead to practically no thrust (the opposite of what they claim) because superconducting EM Drives would display practically no heat losses and hence zero time average Poynting vector.

4) Considering the HDPE dielectric acting as a sink (energy flowing from the EM Drive towards the HDPE where the energy is dissipated internally in the dielectric polymer due to its tandelta and hence irretrievably lost instead of being reflected), the Poynting vector would be directed towards the HDPE dielectric, that is towards the small base, and hence the EM Drive should experience a recoil force and acceleration towards the big base.  This is the opposite direction force found in NASA's experiments with the dielectric.  (Recall that NASA Eagleworks found no thrust force with mode TE012 without a HDPE dielectric and that with the HDPE dielectric inserted at the small base they found a force and acceleration directed towards the small base.)

« Last Edit: 05/08/2015 02:21 PM by Rodal »

Offline jmossman

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I realize this is dredging up an old discussion, but wanted to suggest an additional factor that may have been overlooked in the Chinese/Shawyer/Eagleworks comparison:  the losses from the antenna within the cavities.

Folks:

In the meantime, lets ask why 60 watts of relatively harmonic free sine-wave RF power at the 1,937.118 MHz AKA the TM212 resonant frequency in this copper frustum cavity, can only generate a paltry ~60uN, whereas the Chinese claimed to have produce 160,000uN using just ~150 watts of 2,450 MHz RF signals from a magnetron?  The magnetron RF signal source that is anything but a pure sine-wave generator, that instead has a modulated FM bandwidth of at least +/-30 MHz that is also concurrently amplitude modulated (AM) with thermal electron noise. 


Taking a critical look at this question, and knowing that the spectral shape of a magnetron looks like (see below) compared to a CW spike. It seems evident that a CW spike isn't the best waveform to use if you want to maximize thrust. Dollars to donuts says the Chinese are making full use of the available bandwidth of their resonant cavity by using that noisy magnetron. Magnetrons have lots of phase noise too. You can't easily use them on phased array radars because of that for example.
...
I agree with Mulletron that the answer to Paul March's question is that it is much more effective to have a distributed power spectral density than the power concentrated at a single frequency spike.  When the natural frequency changes in an unpredictable manner, it is much more effective to have a distributed power spectral density of excitation (it is the power spectral density ( http://en.wikipedia.org/wiki/Spectral_density#Power_spectral_density ) over the spectrum of changing natural frequencies that matters).
...
This is evident from the very low Q's reported by NASA (7K to 22K) compared with the Chinese, who report a Q=117K
Quote from: Juan Yang
the resonant frequency and quality factor of the independent microwave resonator system are 2.44895 GHz and 117495.08 respectively
...
NASA's reported Q for the vacuum experiment is a meager Q = 6726, which is 17 times smaller than the Chinese reported Q = 117495.

Zen-in nicely summarized the effect of an antenna within a resonant cavity:
...
A long time ago an RF engineer friend explained to me that cavities, filters and LC circuits are never dissipative.   The power either goes through them or is reflected.   If an RF signal with 20 MHz of bandwidth at 2085 MHz is sent through a 5 pole cavity filter with 5 MHz passband a large fraction of the RF power is simply reflected back to the amplifier.   

In the diagrams I have seen of both the Chinese and latest Shawyer designs, I see an effective antenna source which is significantly more efficient at injecting energy into the cavity than extracting energy out of the cavity.   In contrast, I see a loop antenna within the Eagleworks design which does not have nearly the same effective beam shape, and therefore couples/extracts energy from the cavity far more than the Chinese/Shawyer designs.

I've attached some incredibly crude annotated diagrams trying to show a hypothetical path of a reflected wave.  I've taken huge artistic license and the diagrams are no where close to be scientifically accurate (reflection angles, etc).  However, the use of the magnetron has more than just a wide bandwith;  the waveguide port feeding the cavity will look like a very directional antenna and will not couple/extract energy efficiently that is traveling perpendicular to the waveguide port.  Once a resonance is excited within the cavity/frustum, a majority of the energy will be in the axle direction which is perpendicular to the injection waveguide port.

This contrasts sharply with the loop antenna within the Eagleworks cavity.  While I don't know the exact antenna beam pattern/shape, I suspect a dipole isn't a bad approximation;  this means that the loop antenna couples/injects and couples/extracts equally well in the parallel direction to the conical walls.  While a majority of the resonant energy is between the small and big plates, some energy will be parallel to the conical walls where the loop antenna can couple/extract energy which gets fed back to the amplifier.

If the above reasoning is sound (and perhaps it is not;  I am not an RF engineer and haven't dealt with these concepts in many years), then the frustum when excited by a magnetron/waveguide perpendicular to the conical major axis can build to energy levels higher than the Eagleworks loop antenna design (using the same input energy).  From my layperson's perspective, the magnetron/waveguide approach would also seem to introduce a time constant into mix as a cavity "charge time" (and discharge time).

Best Regards,
James

Offline Mulletron

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From the letter linked to below:

Quote
Note here that we are choosing to work with the
momentum density associated with the canonical energy
momentum tensor rather than the Poynting vector; the
latter is expected to integrate to zero [9]

Quote
Further,
they should be arranged so that the resulting tetrahe-
dron (with the four particles placed at the vertices) has
no parity symmetry so that the vacuum photons get to
see a chiral structure. If these conditions are fulfilled
then a non-zero momentum develops which scales as the
fourteenth inverse power of the length scale of the tetra-
hedron
.

http://arxiv.org/pdf/1011.4376.pdf
http://iopscience.iop.org/0295-5075/93/4/41002/fulltext/epl_93_4_41002.html

Don't think I've linked to this one before.

Quote
Structure of polyethylene consists of directed tetrahedral configuration of sp3 hybridized carbon bonds along repeat structure with no free valence electrons.
http://plastics.tamu.edu/class-resources/semi-conducting_polymers

« Last Edit: 04/05/2015 12:22 AM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Online Rodal

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From the letter linked to below:

Quote
Note here that we are choosing to work with the
momentum density associated with the canonical energy
momentum tensor rather than the Poynting vector; the
latter is expected to integrate to zero [9]

Quote
Further,
they should be arranged so that the resulting tetrahe-
dron (with the four particles placed at the vertices) has
no parity symmetry so that the vacuum photons get to
see a chiral structure. If these conditions are fulfilled
then a non-zero momentum develops which scales as the
fourteenth inverse power of the length scale of the tetra-
hedron
.

http://arxiv.org/pdf/1011.4376.pdf
http://iopscience.iop.org/0295-5075/93/4/41002/fulltext/epl_93_4_41002.html

Don't think I've linked to this one before.

Quote
Structure of polyethylene consists of directed tetrahedral configuration of sp3 hybridized carbon bonds along repeat structure with no free valence electrons.
http://plastics.tamu.edu/class-resources/semi-conducting_polymers

Thank you for bringing attention to this paper.  Easier to read because it is shorter than their usual papers !.  I noticed that they used Mathematica as well to calculate their functions.  I am adding calculating the momentum density associated with the canonical energy momentum tensor to my "list of things to do when I have a chance."  At first glance it seems to me that unless one takes into account an anisotropic HDPE dielectric I am not going to find anything new, because I expect all the terms of the divergence of the canonical energy momentum tensor (for  the EM Drive with an isotropic HDPE dielectric section) to average zero over a period (or multiples thereof).

I also notice that they state the non-trivial contribution is a 4th order term in a perturbation analysis of the nonlinear problem of  mapping between object profile and scattered field: http://en.wikipedia.org/wiki/Lippmann%E2%80%93Schwinger_equation
http://www.ece.neu.edu/faculty/devaney/ppt/stanford.ppt
 
!

Quote
It is shown that the first non-trivial contribution of the momentum transfer to the object from the radiation field occurs at fourth order in the Born series.
The fourth order terms are usually neglected in most treatises !  Actually, sometimes the second order Born terms are taken into account (for example in http://en.wikipedia.org/wiki/Grazing-incidence_small-angle_scattering  ), but I don't know of applications that have used the 3rd order term and much less the 4th order term. 

So even if the authors are correct, it is no wonder that this is stuff that is usually neglected.
.  According to the authors it only appears when there is

1) an anisotropic (chiral) medium
and
2) taking into account 4th order terms in a perturbation analysis




Let's look again at the energy-momentum tensor:







I have already calculated the divergence of the Poynting vector for the EM Drive (without any HDPE dielectric insert), that is the divergence of the momentum density components Sx/c =T01 , Sy/c =T02 , Sz/c =T03 and will post the images when I have a chance and have checked my results.

EDIT 1: yes, the paper itself states:

Quote
One should also note that for purely dielectric scatterers, the momentum is expected to vanish as the electromagnetic momentum density coincides with the Poynting vector.

So perhaps the only experimenters that have found something along these lines is NASA Eagleworks due to Paul March trying the PTFE and HDPE dielectric polymer inserts, and without them there is really no thrust (one of the very interesting things disclosed by Paul March is that Neoprene Rubber gave negligible thrust force). This would mean that the experimental forces measured by Shawyer and Juan Yang in China for EM Drives (using much higher power input) without thermoplastic inserts maybe just thermal effect artifacts.

EDIT 2: It the authors are correct and one needs to take into account nonlinearity + anisotropy to get momentum from the quantum vacuum, this is much more complicated stuff than what Dr. White or Dr. Woodward have been considering.  It will be much more difficult to prove or disprove ....There are non-uniqueness issues associated with an inverse nonlinear problem, and many other complications...There is no unique canonical correction to the energy-stress tensor, there are several and it is not clear which one is right for the problem....

« Last Edit: 04/05/2015 03:59 AM by Rodal »

Offline ThinkerX

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Quote
So perhaps the only experimenters that have found something along these lines is NASA Eagleworks due to Paul March trying the PTFE and HDPE dielectric polymer inserts, and without them there is really no thrust (one of the very interesting things disclosed by Paul March is that Neoprene Rubber gave negligible thrust force). This would mean that the experimental forces measured by Shawyer and Juan Yang in China for EM Drives (using much higher power input) without thermoplastic inserts maybe just thermal effect artifacts.

EDIT 2: It the authors are correct and one needs to take into account nonlinearity + anisotropy to get momentum from the quantum vacuum, this is much more complicated stuff than what Dr. White or Dr. Woodward have been considering.  It will be much more difficult to prove or disprove ....There are non-uniqueness issues associated with an inverse nonlinear problem, and many other complications...There is no unique canonical correction to the energy-stress tensor, there are several and it is not clear which one is right for the problem....

So is this a brick wall or a convoluted maze for the EM Drive?  Are these thermoplastic inserts suitable long term use in the environment created by the EM Drive?  (thinking of the amount of heat this device produces)  Is there someway they could be modified to increase thrust?

Offline Star-Drive

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Dr. Rodal:

I think that the reason why the Neoprean rubber didn't generate any detectable thrust with the ~30W of available power was that it's carbon loaded which increases its RF loss tangent from that of HDPE or PTFE (~0.0004) up to 0.02 which really loads down the net E-field generated in the cavity for a given input power.  And since we think that the thrust effect we are observing is proportional to E-field squared (E^2) that could make a huge difference in performance.

Now please note that I concur with your analysis on the E&M Poynting vector time averaging to zero in the frustums.  For example when the Cannae pillbox cavity's input RF power feed is well Z-matched with a VSWR= ~1.00, the RF Poynting power flow into the cavity is always towards the large OD pancake section of the cavity.  If one envisions the quantum vacuum (Q-V) as a semi-virtual electrical plasma as Dr. White does, that would imply that the Poynting power flow vector would entrain the Q-V plasma and send it on its way toward the pillbox end of the cavity and then out of the cavity, the back-reaction on the cavity should be in the opposite direction towards the RF feed end of the Cannae test article, but the observed thrust vector is opposite to that surmise, i.e. toward the shorter RF sense antenna end of the cavity per the attached slide. 

Now Per the newly authored Q-V plasma simulation code that Dr. White just finished, the equal bidirectional Q-V plasma flow for the Cannae cavity comes from the high-Q pancake section with a Q of ~9,000 for the un-slotted version of the cavity.  However due to the high E-field region created n the throat of the RF feed, this cylindrically shaped high E-field volume acts as an obstruction to the Q-V plasma flow.  This E-field obstruction created in the PTFE cylinder then accelerates the Q-V plasma around it in a Bernoulli like effect that accelerates the Q-V plasma flow coming from the main pillbox cavity.  This unbalanced and accelerated Q-V plasma flow that goes away from the large pill box cavity in the direction of the RF input section is what generates the NET thrust in our model.   

Next, using this new Q-V plasma simulation tool that utilizes the instantaneous E&M fields from COMSOL for one complete RF cycle in 5 degree increments as its input file, we are now seeing why we need the PTFE or HDPE dielectrics in the frustum while using near pure sine wave power levels below ~100W in the ~2.0 GHz frequency range to generate detectable thrust, and why Shawyer and the Chinese didn't while pumping 80W to 2,500W using magnetron RF sources.  We think the reasons are two fold. 

The first is that Shawyer and the Chinese both used magnetron RF sources for their experiments.  An RF source that generates large AM, FM and PM modulation of the carrier wave with typical FM modulation bandwidth on the order of at least +/-20 MHz.  (These time rate to change of energy modulations increase the Q-V density in our model.) 

The second reason we found running these 3D Q-V plasma simulations for the EMPTY copper frustum, was that increasing the input power tends to focus the Q-V plasma flow from near omnidirectional from the frustum at low powers, to a much more jet like beam at higher powers measured in kW to tens of kW-rf.  In fact the simulation for the 100W run predicted only ~50uN for our pure RF system with dielectric, while the 10kW run predicted a thrust level of ~6.0 Newton without a dielectric in the cavity.  And at 100kW-rf it was now up to ~1300 Newton, but the input power to thrust production nonlinearity was starting to taper off around 50kW.   Of course these Q-V plasma thrust predictions are based on the Q-V not being immutable and non-degradable, a feature we admit is not widely accepted by the mainstream physics community, at least at the moment. :)

Lastly, due to the above non-linear thrust scaling with input power predictions, we have started the build up of a 100W-to-1,200W waveguide magnetron RF power system that will drive one of our aluminum RF frustum cavities.  Initially the test rig will follow Shawyer's first generation test rig that used a tetter-totter balance system in air only to see if we can generate similar thrust levels that Shawyer reported using a hermetic sealed box, which were in the ~16 to 300 milli-Newton range dependent on the Q-Factor of the frustum.

BTW, the reason we included the "what-if" Eagleworks can make this thing work solar system trajectory section on our 2014 JPC paper was that we have to continually tell management the value proposition for why they should fund our research, much in the same way we have to convince Chris Bergin here at NSF we really will be talking about space applications for these Q-Thruster like devices, once we get our hands around the physics they are using.  However when we do, the solar system and beyond will be ours for the picking...

Best, Paul M.

Offline Stormbringer

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My analysis: "Mind Blown...resetting."   ;D

When antigravity is outlawed only outlaws will have antigravity.

Offline flux_capacitor

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Moving to higher power magnetron-based experiments is VERY good news! :)

Lastly, like any busy lab, Eagleworks could always use extra funding to deal with its daily heart burns and required salaries to keep it going.  However we are currently a NASA sponsored facility, which sadly precludes being able to accept crowd sourcing or any other outside source of funding, unless it's through a commercial NASA Space Act Agreement that has to be approved up through NASA headquarters in Washington DC.

Paul, a contributor on Talk-Polywell forums, Carl White, asked this interesting question:
Quote
They can't accept dollars, but can they still accept donations of equipment? What about equipment "sold" to them for $1? Could provide some RF amplifiers for example.
So would it be possible to give you some contribution in kind? If so, what do you need?

Offline Paul451

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Carl White, asked this interesting question:
Quote
They can't accept dollars, but can they still accept donations of equipment? What about equipment "sold" to them for $1? Could provide some RF amplifiers for example.
So would it be possible to give you some contribution in kind? If so, what do you need?

In general, government regs forbidding accepting gifts include "or value" precisely to avoid that loophole.╣ So equipment, whether donated or "sold" for $1, is still a donation of value. IIRC, even volunteering your own labour is forbidden unless specifically authorised.

It's the same with NASA's unused facilities. NASA can't donate time to a private company, even if the facility (or staff!) would otherwise go unused, because they are required to charge "full equivalent commercial rates" or similar wording. The only exemption is if NASA and the private user "exchange services of equivalent value" via an SAA. NASA has been interpreting "equivalent value" as the private user letting NASA researchers play with their toys, which Congress has cracked down on recently.

That said, an exemption for crowd-sourced donations makes sense. Similarly, a Patreon type system where fanbois sponsor their favourite research project via a small monthly amount. It may be something worth lobbying for. Even if it is just a pro-forma authorisation for agency officials to be able to use SAA's for specific crowd-sourcing efforts. Unfortunately, SAA's have been tightened even further by Congress.

╣ For example, if I pay the tuition fees for the children of a government official to go to a private-school/top-university, or give them a free car/house/cheap-loan, etc, it's still bribery even though there was no cash-in-hand.
« Last Edit: 04/05/2015 03:09 PM by Paul451 »

Offline Star-Drive

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Carl White, asked this interesting question:
Quote
They can't accept dollars, but can they still accept donations of equipment? What about equipment "sold" to them for $1? Could provide some RF amplifiers for example.
So would it be possible to give you some contribution in kind? If so, what do you need?

In general, government regs forbidding accepting gifts include "or value" precisely to avoid that loophole.╣ So equipment, whether donated or "sold" for $1, is still a donation of value. IIRC, even volunteering your own labour is forbidden unless specifically authorised.

It's the same with NASA's unused facilities. NASA can't donate time to a private company, even if the facility (or staff!) would otherwise go unused, because they are required to charge "full equivalent commercial rates" or similar wording. The only exemption is if NASA and the private user "exchange services of equivalent value" via an SAA. NASA has been interpreting "equivalent value" as the private user letting NASA researchers play with their toys, which Congress has cracked down on recently.

That said, an exemption for crowd-sourced donations makes sense. Similarly, a Patreon type system where fanbois sponsor their favourite research project via a small monthly amount. It may be something worth lobbying for. Even if it is just a pro-forma authorisation for agency officials to be able to use SAA's for specific crowd-sourcing efforts. Unfortunately, SAA's have been tightened even further by Congress.

╣ For example, if I pay the tuition fees for the children of a government official to go to a private-school/top-university, or give them a free car/house/cheap-loan, etc, it's still bribery even though there was no cash-in-hand.

What Paul451 said.

All:

Just to make Chris happy, lets assume that the Eagleworks' current Q-V plasma code thrust predictions for the TM010 or TM011, 942 MHz resonant mode running at 100kW is correct for our copper frustum, see attached slide, and we then attached it to a commercial 100kW, 2.45 GHz magnetron, see second attached slide.  What you might get is a ~2,000 Newton thruster with an effective Isp of well over one million seconds dependent on the attributes of the selected power plant needed to drive it.  Now what could one do with that kind of thruster system for a human Mars or say Saturn trips if we specified the use of an LENR based 1.0 MWe reactor that needs very little radiation shielding.

Best, Paul M.

Offline flux_capacitor

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If a cubesat experiment in space cannot be done (due to insufficient funding for now), very high power experiments (10-100 kW) in ambient air are the only way to go, to prove the EmDrive does work as expected:

- Shawyer experiments in ambient air (as well as newer superconducting designs) are now kept under a shroud of secrecy. 

- Chinese mid-to-high power experimental results (~ 2000 W) in ambient air are on the contrary regularly published in academic journals, but are still uncertain because Pr. Juan Yang is not able to share additional data, and spurious causes like air currents are not ruled-out.

- Eagleworks ruled-out the possibility of ambient air currents, running the experiments in a hard vacuum. But because the setup needs to be compact and light enough to sit into the vacuum chamber and hang on the sensitive torsion pendulum (power source included), the amp had to be very weak (10 to 30 watts only) and moreover leaked/sparked in that lower pressure environment. Hence, sadly, less than a hundred micronewtons of thrust. Because of the tiny thrust signatures just above the seismic noise, the results published so far created more questions about other possible spurious causes (EM interaction with the torsion pendulum, the walls of the chamberů).

IMHO, only a very high power experiment producing a very high thrust (above a newton and more), and if possible even lift-off, where air flow circulation around the cavity could not account for the enormous thrust measured by equipment and observed with our own eyes, will settle the case. And will open the colonization of our solar system.
« Last Edit: 04/05/2015 08:03 PM by flux_capacitor »

Online Cinder

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LENR
Probably beyond the speculation tolerance of NSF :(  Does no proven power source (e.g. SEP, but even nuclear) make for a propulsion system that's competitive enough with existing and more conventional propulsion schemes, for short term applications?

Nuclear currently is, separately, a non-starter as well.  But opening up the solar system as conjectured with EM propulsion -- that would probably upset the public and industrial status quo enough to cause some reconsideration.. ?  EM merely needs to beat the alternatives:
we have to continually tell management the value proposition for why they should fund our research, [...] once we get our hands around the physics they are using.
  Utter revolution is accessory as a very short term goal; but probably inevitable anyway, if EM propulsion took off.
« Last Edit: 04/05/2015 08:29 PM by Cinder »
The pork must flow.

Offline tchernik

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IMHO, only a very high power experiment producing a very high thrust (above a newton and more), and if possible even lift-off, where air flow circulation around the cavity could not account for the enormous thrust measured by equipment and observed with our own eyes, will settle the case. And will open the colonization of our solar system.

Fully agree. Subtle pushes able to move a paper sheet in the vacuum of space in 0G are unlikely to attract any funding, because even if it works, it won't convince people that have already made their minds and are certain things like that can't be real.

While a self propelled chariot moving around on EM thrust alone would make some heads turn. And a flying demonstrator would be nearly irrefutable.
« Last Edit: 04/05/2015 08:31 PM by tchernik »

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