I really wish I could get somebody else on board with this idea because I absolutely will fail on my own.

Quote from: Notsosureofit on 03/10/2015 01:29 am@ RODALJust got a minute but from your p expression;If L1/c1 = L2/c2del f = (1/2*f)*((c1*c2)/(L1*L2))*b^2*((1/dD1^2)-(1/dD2^2))might be a solution ??Got to check the thinking later.Night !I find your previous expressiondel f = ( f/(2*c^2)) * (c1^2-c2^2)more physically appealing, since it goes to zero for equal dielectric constants, regardless or their dielectric length, while on the other hand del f = (1/2*f)*((c1*c2)/(L1*L2))*b^2*((1/dD1^2)-(1/dD2^2))goes to zero for equal dielectric lengths, regardless of their dielectric constants.

@ RODALJust got a minute but from your p expression;If L1/c1 = L2/c2del f = (1/2*f)*((c1*c2)/(L1*L2))*b^2*((1/dD1^2)-(1/dD2^2))might be a solution ??Got to check the thinking later.Night !

With the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.

@Star-Drive :I'm still asking about the huge discrepancy between the expected linear displacement of 32.3µm (assuming only flexure bearings restoring torque) in response to a calibration pulse of 29.1µm and the actual readings on chart vertical scale of a linear displacement between 1µm to 2.5µm for the calibration pulses.There is an inconsistency of an order of magnitude between values as expected from flexure stiffness and as recorded on the display. Is it acknowledged or investigated by the team at Eagleworks ?I'm not objecting that the thrusts measurements would not be proportional (ie for twice the deviation of cal. pulse => twice 29.1µN) but since the fixed ratio of µm displacement per µN of thrust is at the heart of the experiment, such discrepancy can only weaken the case for the charts published so far. This needs to be clarified anyhow. It could be a problem of calibration of the Philtec D63 gain, or a biased scaling factor between the analog outputs of the D63 and the final rendering of vertical scale on display...

Quote from: Rodal on 03/10/2015 01:42 amQuote from: Notsosureofit on 03/10/2015 01:29 am@ RODALJust got a minute but from your p expression;If L1/c1 = L2/c2del f = (1/2*f)*((c1*c2)/(L1*L2))*b^2*((1/dD1^2)-(1/dD2^2))might be a solution ??Got to check the thinking later.Night !I find your previous expressiondel f = ( f/(2*c^2)) * (c1^2-c2^2)more physically appealing, since it goes to zero for equal dielectric constants, regardless or their dielectric length, while on the other hand del f = (1/2*f)*((c1*c2)/(L1*L2))*b^2*((1/dD1^2)-(1/dD2^2))goes to zero for equal dielectric lengths, regardless of their dielectric constants.The previous expression is only valid approximation for a "uniformly varying dielectric". There is no L1 and L2 in that case.What do you think might maximize the second expression ? (valid only for L1/c1 = L2/c2 )

By keep the diameter of the Small End constant, increase the large end of the cavity, in order to have the same resonant frequency, cavity height must be reduced, quality factor also reduce.

http://www.emdrive.com/NWPU2010translation.pdfIn the conclusion area, last sentence in 3rd paragraph, next to last page.QuoteWith the Small End of the cavity unchanged, the quality factor and thrust decrease with the increase in the Large End.Seems to be a summary of this on page 8:QuoteBy keep the diameter of the Small End constant, increase the large end of the cavity, in order to have the same resonant frequency, cavity height must be reduced, quality factor also reduce.

Quote from: frobnicat on 03/10/2015 09:50 am@Star-Drive :I'm still asking about the huge discrepancy between the expected linear displacement of 32.3µm (assuming only flexure bearings restoring torque) in response to a calibration pulse of 29.1µm and the actual readings on chart vertical scale of a linear displacement between 1µm to 2.5µm for the calibration pulses.There is an inconsistency of an order of magnitude between values as expected from flexure stiffness and as recorded on the display. Is it acknowledged or investigated by the team at Eagleworks ?I'm not objecting that the thrusts measurements would not be proportional (ie for twice the deviation of cal. pulse => twice 29.1µN) but since the fixed ratio of µm displacement per µN of thrust is at the heart of the experiment, such discrepancy can only weaken the case for the charts published so far. This needs to be clarified anyhow. It could be a problem of calibration of the Philtec D63 gain, or a biased scaling factor between the analog outputs of the D63 and the final rendering of vertical scale on display... Frobnicat & Crew:Dr. White and his NASA interns are the folks who performed the original force calibration work on this torque pendulum, so your questions might be bettered answered by him. However, it's my understanding that the torque pendulum's actual micron displacement observed for each test run is dependent on its specific total active mass load, balance weights and all their locations on the torque pendulum arm for the test run in question. So as long as we reference the near constant calibration force from our electrostatic fin calibration system before and after each test run, and then use that specific displacement yardstick of the moment as the true measure of the test article's generated forces, it doesn't matter what the actual micron displacement turns out to be for each data run. And that has been what we've used to date report our generated forces. If there is a major problem with that approach please let us know. Best, Paul M.

Quote from: Rodal on 03/09/2015 11:32 pmQuote from: RotoSequence on 03/09/2015 11:07 pmWe've been laser-focused on materials with greater dielectric constants, but what about materials with similar dielectric constants, like fused quartz? Will the EM drives behave differently?If Paul March discussed testing with dielectric materials other than Teflon and HD PE, I don't recall. It would be interesting if Paul could comment (or if Paul already discussed this, if somebody could bring the experimental results to our attention).I understand that Roger Shawyer tested non-polymer materials as dielectrics, but the specific results and the dimensions and material properties of the dielectrics tested were not disclosed (again, if anyone has more specific details, please bring them to our attention).Dr. Rodal:We've only tried polyethylene, Teflon, neoprene rubber and aluminum oxide discs so far, with PE and PTFE being the most productive. However what dielectric if any will prove to be optimal in generating the most thrust in these EM-Drive like thrusters is really dependent on what physics is really driving their operation. So far the dielectrics with the largest electrostrictive coefficient combined with a largest Q-factor appear to be the winners. This implies to me that fused quartz may be a good candidate, since it has a large Q-factor with moderate electrostrictive coefficient and piezoelectric responses. BTW, these dielectrics may prove to be the E&M/gravity field to mechanical converters needed to generate thrust. On the other hand if Shawyer and the Chinese are right in their statements that they used no dielectrics in their tens to hundreds of milli-Newton thrusters, then these dielectrics may just be means of amplifying the underlying effects that are generated just by the action of the E&M fields on the copper or silver atoms in the walls of the frustum resonant cavity. Remember that though copper and silver only have a real permittivity of 1.0, in temporal space they have a complex permittivity of greater than 100. and this is the parameter that drives E to B-field phase shifting over very small distances at microwave frequencies, (~2 microns deep at 2.0 GHz). I.e. these metallic atoms can undergo very large cyclic accelerations around their crystal lattice positions as the E&M wave fronts are dissipated in them.

Quote from: RotoSequence on 03/09/2015 11:07 pmWe've been laser-focused on materials with greater dielectric constants, but what about materials with similar dielectric constants, like fused quartz? Will the EM drives behave differently?If Paul March discussed testing with dielectric materials other than Teflon and HD PE, I don't recall. It would be interesting if Paul could comment (or if Paul already discussed this, if somebody could bring the experimental results to our attention).I understand that Roger Shawyer tested non-polymer materials as dielectrics, but the specific results and the dimensions and material properties of the dielectrics tested were not disclosed (again, if anyone has more specific details, please bring them to our attention).

We've been laser-focused on materials with greater dielectric constants, but what about materials with similar dielectric constants, like fused quartz? Will the EM drives behave differently?

Quote from: Mulletron on 03/10/2015 07:32 amI really wish I could get somebody else on board with this idea because I absolutely will fail on my own.I'm sorry that I can't be of much help in this area, but for what it's worth, I think your theories are worth exploring by those who have the knowledge, background, and ability to do so.

@Dr. Rodel - Did you use your magic formulas to calculate the resonance frequencies of the newest Eagleworks cavity from Paul? Including dielectric effects? If so, what were the numbers?

Quote from: aero on 03/10/2015 10:06 pm@Dr. Rodel - Did you use your magic formulas to calculate the resonance frequencies of the newest Eagleworks cavity from Paul? Including dielectric effects? If so, what were the numbers?I obtained exact solutions so far for:1) Truncated cone with only one dielectric medium in the cavity2) Cylindrical cavity with two dielectric coupled mediumsI haven't had the time to derive the formula for the Truncated Cone with two dielectric mediums to consider the case with vacuum and HD-PE. I did calculate the Eagleworks cavity without the HD-PE dielectric section.

I did calculate the Eagleworks cavity without the HD-PE dielectric section.

....QuoteI did calculate the Eagleworks cavity without the HD-PE dielectric section.And what number did you get?