I figure this may be of interest to @Rodal (you dig Finite element analysis) and @Notsosureofit (your hypothesis featuring an accelerated frame of reference).
http://people.clarkson.edu/~nanosci/jse/B/inpress/vaish.pdf
Yes, that is exactly what the Notsosureofit hypothesis is based on.
Assume that the wave guide is rectangular and the gravitational potential
U is generated by a piece of point matter located at the point (R, 0). Then,
U(x, y) = − GM ((x − R)2 + y2)1/2
where G is the gravitational constant and M is mass of the earth. The
waveguide cross section is [0, A] × [0, B] where R >> A, B. For example,
we can take A = 3, B = 2 and R = 10 and formulate the finite element
technique for this problem.
)
Remember that 10^-17 ?

...
I had little control over what was modeled or presented only was asked for the dimensions of the cavity in the FEKO model.
I've requested a version of FEKO to run and confirm my cavity actions. Waiting for a email from them to be able to download.
I stated I was after TE012.
As far as meep goes other than pulling out the CSV file and log files you have little idea of values.
Didn't you and aero come up with a agreed on X, Y, Z coordinate system where the frustum as viewed sitting flat on the large end plate? See attachment
According to the convention we had agreed, which is the same as the picture you show, then SEZ_vueEx should be the Electric field in the direction parallel to the end plate, and measured at the small end (SE).
But then, the SEZ_vueEx (and other) images shown in the Meep files you linked to do not make any sense. No mode shape can result in an electric field parallel to a metal, measured at the metal.
BOUNDARY CONDITION FOR AN ELECTRIC FIELD: The tangential Electric Field will always be zero on a metal surface. This is because the free charge will swim around and cancel it out, simply by the attractive nature of charge.
Either the Meep model is not correctly modeling the boundary conditions, in which case the whole Meep model is complete nonsense, or SEZ_vueEx has a value very close to zero. If SEZ_vueEx is showing a very small number, there is no way to tell what the images mean: they have no numerical field values and there is no way to tell which images are significant. From your answer << have little idea of values.>> you cannot tell either, since the Meep files do not show the numerical fields.
So, there is no way to tell from these Meep images which ones make any sense, except to tell that SEZ_vueEx for example does not make any sense and therefore there is no way to tell what is going on, much less to tell what mode shape is present.
I snagged this image from the reference:
https://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_maschinenwesen/ilr/rfs/forschung/folder.2007-08-21.5231434330/ag_raumfahrtantriebe/JPC%20-%20Direct%20Thrust%20Measurements%20of%20an%20EM%20Drive%20and%20Evaluation%20of%20Possible%20Side-Effects.pdf
and counted pixels using a tool new to me, so the count was not very repeatable, but these are the numbers:
Small diameter = 134 px
big diameter = 184 - 187 px
slant height = 142 - 147 px
Using small diameter, Ds = 77 mm and calculating by ratio, gives big diameter ~ 105.7 mm to 107.5 mm and slant height ~ 81.6 mm to 84.5 mm
I don't know what that proves, but as a sanity check it doesn't seem all that close to anyone's numbers.Please take into account that the internal height is adjusted internally with a screw prior to testing, so the internal height at resonance can be much smaller than the actual exterior height of the cavity
Yes, consider that it can be shorter. But it can't be longer which kind of rules out axialLength = 2*(0.0686 - 0.003) meter (since the wall thickness is 3 mm)
Which means that
The dimensions I calculated a long time ago here: https://forum.nasaspaceflight.com/index.php?topic=39004.msg1477474#msg1477474
Axial Length = 0.100842 m = 0.735*2*0.0686 m
are very much in play !
Welll... The next thing I did was to snag the COMSOL image from the reference, attached. It seems to me that this drawing should be to scale and should show the interior dimensions. Using the pixel measuring method, I find:
px px ref. 77 77
sd 244 241.9 77 77 ave
bd 341.1 339.2 107.6422131148 107.0426229508 107.3424180328
shi 211.4 206.8 66.712295082 65.2606557377 65.9864754098
shi 212.5 208.1 67.0594262295 65.6709016393 66.3651639344
66.1758196721
That is, with small diameter = 0.77 mm, by ratio the big diameter = 107.34 mm and the height = 66.176 mm. But at least that is close to one of the dimensions given previously.

I'll just have to make sure I fix that so I can have something other than questionable models, this includes FEKO and meep.
Shell
I'll just have to make sure I fix that so I can have something other than questionable models, this includes FEKO and meep.
Shell
Nicely said.
TE01x mode has a unique end plate characteristic. The end plate currents do not cross over to the side walls & there is only 1 annular current ring. See attached.
No other TE & TM mode does this. Should be very easy to see this on any sim.
Have also read building in a thin but totally insulating gap between the end plates to the side walls suppresses all modes that need end plate to side wall currents to exits (so the mode can form). This should stop the degenerative but equal guide wavelength TM11x mode from trying to form / forming.
Anyway just look at the end plate for a single annular current ring. If it is not there, it is not TE01x mode.

No, that can not be an electric current ring at the end plate of an EM Drive, that would only be true for an open waveguide without any metallic ends !!!
Again, the tangential electric field, parallel to a metal, must be zero at the metal end plates.
I'll just have to make sure I fix that so I can have something other than questionable models, this includes FEKO and meep.
Shell
Nicely said.
TE01x mode has a unique end plate characteristic. The end plate currents do not cross over to the side walls & there is only 1 annular current ring. See attached.
No other TE & TM mode does this. Should be very easy to see this on any sim.
Have also read building in a thin but totally insulating gap between the end plates to the side walls suppresses all modes that need end plate to side wall currents to exits (so the mode can form). This should stop the degenerative but equal guide wavelength TM11x mode from trying to form / forming.
Anyway just look at the end plate for a single annular current ring. If it is not there, it is not TE01x mode.
<<Anyway just look at the end plate for a single annular current ring. If it is not there, it is not TE01x mode.>>
No, that can not be an electric current ring at the end plate of an EM Drive, that would only be true for an open waveguide without any metallic ends !!!
Again, the tangential electric field, parallel to a metal, must be zero at the metal end plates.
The only field that can show up at the end plates of the EM Drive having metal end plates for mode TE01p is a magnetic field.
People, we learned this at school: BOUNDARY CONDITIONS for Electric Fields, remember
NASA Eagleworks does not have this misunderstanding. NASA got the fields correct, including the boundary conditions from the very first COMSOL analysis run by Frank Davis.
The EM Drive metallic ends cannot be ignored. The EM Drive is not a waveguide with open ends !!!!
There are boundary conditions at the ends due to the metal !!!
The electric field at the metal end plates in mode TE012 is a big zero (see plot below)
...
This was just posted on the other site. Things are now making a little more sense.
Quote
Some quick notes.
The movies are mislabelled.
The TE01 mode should be TE10. It is not any reference to the frustum, but the dominant mode of the waveguides that are excited by the RF source. I should have not have mentioned the rectangular waveguide mode, it is confusing.
The Feko solver I'm using is method of moments.
The E-field magnitudes shown are not taken on the surface of the frustum (Where they are zero) but 2mm inside.
Feko calculates the standing waves. The animation in these movies are made my changing the phase of the RF sources so affecting the instantaneous E-field magnitude displayed. At 2.47 Ghz, this would be pretty fast!
The frustum walls are perfect conductors.
Note that the E-field scale is logarithmic. This can be misleading or helpful, I'm not sure. Will maybe try a linear scale next time.
I'll do an update with an improved model using copper and S-port measurements soon.
End Quote
I'll just have to make sure I fix that so I can have something other than questionable models, this includes FEKO and meep.
Shell
Nicely said.
TE01x mode has a unique end plate characteristic. The end plate currents do not cross over to the side walls & there is only 1 annular current ring. See attached.
No other TE & TM mode does this. Should be very easy to see this on any sim.
Have also read building in a thin but totally insulating gap between the end plates to the side walls suppresses all modes that need end plate to side wall currents to exits (so the mode can form). This should stop the degenerative but equal guide wavelength TM11x mode from trying to form / forming.
Anyway just look at the end plate for a single annular current ring. If it is not there, it is not TE01x mode.
<<Anyway just look at the end plate for a single annular current ring. If it is not there, it is not TE01x mode.>>
No, that can not be an electric current ring at the end plate of an EM Drive, that would only be true for an open waveguide without any metallic ends !!!
Again, the tangential electric field, parallel to a metal, must be zero at the metal end plates.
The only field that can show up at the end plates of the EM Drive having metal end plates for mode TE01p is a magnetic field.
People, we learned this at school: BOUNDARY CONDITIONS for Electric Fields, remember
NASA Eagleworks does not have this misunderstanding. NASA got the fields correct, including the boundary conditions from the very first COMSOL analysis run by Frank Davis.
The EM Drive metallic ends cannot be ignored. The EM Drive is not a waveguide with open ends !!!!
There are boundary conditions at the ends due to the metal !!!
The electric field at the metal end plates in mode TE012 is a big zero (see plot below)This was just posted on the other site. Things are now making a little more sense.
Quote
Some quick notes.
The movies are mislabelled.
The TE01 mode should be TE10. It is not any reference to the frustum, but the dominant mode of the waveguides that are excited by the RF source. I should have not have mentioned the rectangular waveguide mode, it is confusing.
The Feko solver I'm using is method of moments.
The E-field magnitudes shown are not taken on the surface of the frustum (Where they are zero) but 2mm inside.
Feko calculates the standing waves. The animation in these movies are made my changing the phase of the RF sources so affecting the instantaneous E-field magnitude displayed. At 2.47 Ghz, this would be pretty fast!
The frustum walls are perfect conductors.
Note that the E-field scale is logarithmic. This can be misleading or helpful, I'm not sure. Will maybe try a linear scale next time.
I'll do an update with an improved model using copper and S-port measurements soon.
End Quote
No, that does not make any sense whatsoever
There is no such thing as mode shape TE10 !!!!!!!!!!!!!!!!!!!!
n in TEmnp can never be zero. n can only be 1,2,3, etc.
This is why I'm going to take the time to download and learn FEKO. This just messes with me and the work I've done.
Thanks Dr. Rodal for your time and insight in this.

No, that can not be an electric current ring at the end plate of an EM Drive, that would only be true for an open waveguide without any metallic ends !!!
Again, the tangential electric field, parallel to a metal, must be zero at the metal end plates.
It is for a resonant cavity end plate. Think H field.
See
http://www.ganino.com/BSTJ/images/Vol26/bstj26-1-31.pdf
As per the attached, Blue = H field, the NASA & Bell lab data for the currents in the end plate of a resonant cavity align.
There are no end-plate to end-walls currents in the TE01X modes only if the symmetry in the cavity is perfect to within ~1/100th of wavelength of the driven frequency. For a 2.45 GHz drive signal that has a wavelength of 0.1223643 meters in-vacuum, that implies a required frustum build tolerance of +/-1.2mm.
No, that can not be an electric current ring at the end plate of an EM Drive, that would only be true for an open waveguide without any metallic ends !!!
Again, the tangential electric field, parallel to a metal, must be zero at the metal end plates.
It is for a resonant cavity end plate. Think H field.
See
http://www.ganino.com/BSTJ/images/Vol26/bstj26-1-31.pdf
As per the attached, Blue = H field, the NASA & Bell lab data for the currents in the end plate of a resonant cavity align.
Recent quote from an expert I respect. No not from Roger.QuoteThere are no end-plate to end-walls currents in the TE01X modes only if the symmetry in the cavity is perfect to within ~1/100th of wavelength of the driven frequency. For a 2.45 GHz drive signal that has a wavelength of 0.1223643 meters in-vacuum, that implies a required frustum build tolerance of +/-1.2mm.
So Shell YES, you can easily identify TE01x mode excitation by the end plate H field pattern & if available by the single annular current ring induced in the end plate by the H field and by the lack of end plate to side wall currents.
Eddy currents produced by the magnetic field in mode shape TE01p will be present even with zero tolerance.[/b]
The quadrupole represents how stretched-out along some axis the mass is. A sphere has zero quadrupole. A rod has a quadrupole. A flat disk also has a quadrupole, with the opposite sign of the quadrupole of a rod pointing out from its flat sides. The rod is a sphere stretched along that axis and the disk is a sphere squashed along that axis. In general, objects can have quadrupole moments along three different axes at right angles to each other. (The quadrupole moment is something called a tensor.)
Here’s to successfully modified frustum which now happily resonates at 2,331 MHz. I removed 8 mm from the small end, resulting in a shorter central length and a bigger diameter of the small end, thus pushing the small end cut-off frequency further down and away from resonance. New cut-off freq is 2,256 MHz which is 75 MHz below test frequency.
These resonance cavities turn out to be remarkably predictable. Simulating new dimensions (in COMSOL) was showing a freq shift of +20 Mhz (2323 MHz-> 2343 Mhz). Actual as-measured freq moved by +19 MHz (2312 MHz->2331 Mhz). 80(?) years-old technologies rule.
New dimensions:
D_big: 264 mm (as before)
D_small: 162 mm (+4 mm)
L_center: 196 mm (-8 mm)
TE012 freq (MHz): Simulated: 2343, Actual: 2331.
Df: 0.69
Small end cut-off: 2,256 MHz.
Q factor (at -3 dB S11): 2300 (went down from the original 3100, not sure if this is due to coupling mismatch under new dimensions, or oxidation from minor torch work, or just aging since the last time it was measured).
If anyone knows why this frustum should not be producing thrust then speak now or forever hold your peace.
Ladies and Gentleman, you can now make your bets. (I have already simulated mode frequency shifts for difference thicknesses of HDPE disks at the small end, so this gives a good hint as to what my own prediction for this upcoming test is…)
0.0019 Newtons (1900 uN). Looking forward to seeing your results.
That Woodward's and White's formulations respect Relativity, including time dilation, does not, by itself, preclude the Alcubierre metric "warp drive". Rather, the Alcubierre "warp drive" problem is the need for "negative mass/energy", something that is not available (and hence considered by many physicists as a non-starter), and it has other important dificulties: https://en.wikipedia.org/wiki/Alcubierre_drive#Difficulties . The creator of the Alcubierre concept, Alcubierre himself is on record saying that the "Alcubierre drive" is not something that can be done:Quote from: Alcubierre"from my understanding there is no way it can be done, probably not for centuries if at all" https://twitter.com/malcubierre/status/362011821277839360