Quote from: rfmwguy on 05/13/2015 02:13 amQuote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/It is getting pretty hot and heavy in here and I'm not sure I am keeping up either. Love it though.I've been mulling around the ideas of harmonics and wondered if anyone has considered injecting 2 RF sources into the cavity, One set and the other variable in frequency? I've been slowly working my way through this but like I said it's been slow. I welcome and inputs and thoughts.I've been wondering about that, and also it looks like this has a high reflected, so feeding it with a 4 port circulator and running the reflected back into antenna 2, and it's reflected into antenna 3.
Quote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/It is getting pretty hot and heavy in here and I'm not sure I am keeping up either. Love it though.I've been mulling around the ideas of harmonics and wondered if anyone has considered injecting 2 RF sources into the cavity, One set and the other variable in frequency? I've been slowly working my way through this but like I said it's been slow. I welcome and inputs and thoughts.
Quote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/
...Best Regards,Todd
I was hoping to build a mini EmDrive using modified intruder alarm (22 GHz) modules as these can be tuned by simply adjusting the voltage and physical dimensions of the Gunn diodes resonant cavity.
Quote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...@WarpTech or other proponents of "dependence of the effect on acceleration", please run the numbers. What would be the acceleration of frustum needed to really drift out of bandwidth for Q around 10000 or otherwise reach a magnitude significant to behaviour of waves inside ?I read it in Shawyer's recent paper, he simulated it on a computer. I don't have that type of software. I've been wishing I did for decades. Since the system moves by attenuation and dissipation, the photons lose momentum and are red-shifted, while the frustum either gains momentum or gains heat from them. You're correct, that the momentum it gains from the photons is in the direction of the photons, but results from the difference in the attenuation in each direction. The photons lose more momentum moving inward than moving outward, because they become evanescent waves. They do not increase their energy, except what they can take away from the frustum. So I see it like ringing a bell. It is the exponential decay from a higher energy state that is giving the thrust. Attempting to make the Q very high to sustain resonance requires reducing the losses, but it is the losses that give it thrust. So... Shawyer increases the angle to make it more like a pill box. Anything over pi/6 is very close to a pill box. Then it should have a higher Q, but it should also have less efficient use of it.If a photon rocket is: F/P = 1/cand the Frustum is: F/P ~ Q/c x pulse widthDesign efficiency should then target: (F*c)/(P*Q) = 1 but in practice < 1This would imply maximizing thrust with a lower value of Q, i.e., we do not want to maximize Q, we want to maximize asymmetry in the attenuation, which is what I'm working on at the moment.Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/
Quote from: frobnicat on 05/13/2015 12:14 am...@WarpTech or other proponents of "dependence of the effect on acceleration", please run the numbers. What would be the acceleration of frustum needed to really drift out of bandwidth for Q around 10000 or otherwise reach a magnitude significant to behaviour of waves inside ?I read it in Shawyer's recent paper, he simulated it on a computer. I don't have that type of software. I've been wishing I did for decades. Since the system moves by attenuation and dissipation, the photons lose momentum and are red-shifted, while the frustum either gains momentum or gains heat from them. You're correct, that the momentum it gains from the photons is in the direction of the photons, but results from the difference in the attenuation in each direction. The photons lose more momentum moving inward than moving outward, because they become evanescent waves. They do not increase their energy, except what they can take away from the frustum. So I see it like ringing a bell. It is the exponential decay from a higher energy state that is giving the thrust. Attempting to make the Q very high to sustain resonance requires reducing the losses, but it is the losses that give it thrust. So... Shawyer increases the angle to make it more like a pill box. Anything over pi/6 is very close to a pill box. Then it should have a higher Q, but it should also have less efficient use of it.If a photon rocket is: F/P = 1/cand the Frustum is: F/P ~ Q/c x pulse widthDesign efficiency should then target: (F*c)/(P*Q) = 1 but in practice < 1This would imply maximizing thrust with a lower value of Q, i.e., we do not want to maximize Q, we want to maximize asymmetry in the attenuation, which is what I'm working on at the moment.Best Regards,Todd
...@WarpTech or other proponents of "dependence of the effect on acceleration", please run the numbers. What would be the acceleration of frustum needed to really drift out of bandwidth for Q around 10000 or otherwise reach a magnitude significant to behaviour of waves inside ?
Entropy is keeping me out of bed....I'm too old for this (etc. etc.)Force is dependent on the rate of change of entropy, (need to get to a thermo book tomorrow), so depends on Power. Degree of change depends on ratio of order to disorder, so Q as representing the difference between a highly monochromatic frequency distribution and the Boltzman distribution of the dissipated power as heat IN AN ASYMMETRICAL FORM DEPENDENT ON THE CAVITY SHAPE AND THE MODE !Good Night ! (I hope ??)
Quote from: SeeShells on 05/13/2015 02:33 amQuote from: rfmwguy on 05/13/2015 02:13 amQuote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/It is getting pretty hot and heavy in here and I'm not sure I am keeping up either. Love it though.I've been mulling around the ideas of harmonics and wondered if anyone has considered injecting 2 RF sources into the cavity, One set and the other variable in frequency? I've been slowly working my way through this but like I said it's been slow. I welcome and inputs and thoughts.From what I gather a magnetron source is full of harmonics and subharmonics...one called it "dirty" which is a good visual... spectrum-wise.I'm not looking at that dirty, more a controlled dirty in the harmonics and sub-harmonics. I remember looking at the spectrum of a magnetron years ago and was appalled at the wild mixture spewing out of it. I don't think a magnetron will do unless a notch filters are used. Still working my way through it, but time for bed.
Quote from: rfmwguy on 05/13/2015 02:13 amQuote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/It is getting pretty hot and heavy in here and I'm not sure I am keeping up either. Love it though.I've been mulling around the ideas of harmonics and wondered if anyone has considered injecting 2 RF sources into the cavity, One set and the other variable in frequency? I've been slowly working my way through this but like I said it's been slow. I welcome and inputs and thoughts.From what I gather a magnetron source is full of harmonics and subharmonics...one called it "dirty" which is a good visual... spectrum-wise.
Quote from: rfmwguy on 05/13/2015 02:13 amQuote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/It is getting pretty hot and heavy in here and I'm not sure I am keeping up either. Love it though.I've been mulling around the ideas of harmonics and wondered if anyone has considered injecting 2 RF sources into the cavity, One set and the other variable in frequency? I've been slowly working my way through this but like I said it's been slow. I welcome and inputs and thoughts.
Quote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/
Quote from: frobnicat on 05/13/2015 12:14 am...Best Regards,Todd
Quote from: Notsosureofit on 05/13/2015 03:24 amEntropy is keeping me out of bed....I'm too old for this (etc. etc.)Force is dependent on the rate of change of entropy, (need to get to a thermo book tomorrow), so depends on Power. Degree of change depends on ratio of order to disorder, so Q as representing the difference between a highly monochromatic frequency distribution and the Boltzman distribution of the dissipated power as heat IN AN ASYMMETRICAL FORM DEPENDENT ON THE CAVITY SHAPE AND THE MODE !Good Night ! (I hope ??)Oh I get it! EM Drive = Entropy Maximization Drive ! Good night!
Email received from Roger Shawyer in regard to a question to verify if Dr. Rodal's Df excel equation is correct....http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=829894
The mapping Shawyer defines can be modelled byDF = 1 - c-dwhere d = difference in diameters >=0and c is some constant >=1; c=e for example
Quote from: WarpTech on 05/13/2015 05:42 amQuote from: Notsosureofit on 05/13/2015 03:24 amEntropy is keeping me out of bed....I'm too old for this (etc. etc.)Force is dependent on the rate of change of entropy, (need to get to a thermo book tomorrow), so depends on Power. Degree of change depends on ratio of order to disorder, so Q as representing the difference between a highly monochromatic frequency distribution and the Boltzman distribution of the dissipated power as heat IN AN ASYMMETRICAL FORM DEPENDENT ON THE CAVITY SHAPE AND THE MODE !Good Night ! (I hope ??)Oh I get it! EM Drive = Entropy Maximization Drive ! Good night!Well, yes, in that sense. The entropy is one more condition, like the Equivalence Principle, that the EM drive has to satisfy. The interesting point is that the entropy change can be related to a force vector. Think back to the semi-permeable membrane example in Thermodynamics 1.
The law that entropy always increases holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.
Quote from: WarpTech on 05/12/2015 02:16 pm...Quote from: Notsosureofit on 05/11/2015 08:50 pm...Todd and Notsosureofit:I found a textbook that is in Google Books that has some formulas (including calculating the Q) for (slabs and also for coaxial) dielectric inserts in a cylindrical cavity. See this:The Google URL is huge, I hope this URL shortener works:start at page 111 on this link http://bit.ly/1FiKoz6Propagation, Scattering and Dissipation of Electromagnetic Waves By A. S. Ilʹinskiĭ, A. Ya SlepyanSeries: IEEE Electromagnetic Waves Series (Book 36)Publisher: The Institution of Engineering and Technology; First Edition edition (December 2, 1993)ISBN-10: 0863412831ISBN-13: 978-0863412837Hopefully this can help you further in analyzing the thrust of a cylindrical EM Drive with a dielectric insert
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Quote from: SeeShells on 05/13/2015 02:33 amQuote from: rfmwguy on 05/13/2015 02:13 amQuote from: WarpTech on 05/13/2015 01:05 amQuote from: frobnicat on 05/13/2015 12:14 am...Best Regards,ToddBarely able to keep pace Todd...its a good thing. maximizing asymmetry in attenuation different from absorption like the stuff I used to work with?http://www.westernrubber.com/products/himag-microwave-absorbers/himag-cavity-resonance-absorbers/It is getting pretty hot and heavy in here and I'm not sure I am keeping up either. Love it though.I've been mulling around the ideas of harmonics and wondered if anyone has considered injecting 2 RF sources into the cavity, One set and the other variable in frequency? I've been slowly working my way through this but like I said it's been slow. I welcome and inputs and thoughts.Maybe first try to state what kind of nonlinear coupling effects could be at play to make a difference ? Linear system => result(wave1+wave2)=result(wave1)+result(wave2) so doing wave1+wave2 would bring nothing new, qualitatively, without a mechanism to explain result(single wave)!=0 in the first place...
An important consequence of thiswork is the demonstration that the loss computed for degeneratemodes propagating simultaneously is not simplyadditive. In other words, the combined loss of two co-existingmodes is higher than adding the losses of two modespropagating independently. This can be explained by themode coupling effects, which is significant when the phaseconstants of two propagating modes are different yet veryclose.
Quote from: TheTraveller on 05/13/2015 08:28 amEmail received from Roger Shawyer in regard to a question to verify if Dr. Rodal's Df excel equation is correct....http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=829894The equation that you refer to was derived by me as an honest effort to elucidate variables, "reading tea leaves", that Shawyer had not explicitly defined (originally with @aero and others to compare numerical predictions with experimental measurements). You repeatedly asked me for Shaywer's Design Factor equation. Obviously, if you had been given the Design Factor equation by Shawyer, or if this expression was obvious to you from reading Shawyer's writings, there was no point in asking me for Shaywer's Design Factor (I hope and fully expect that in that case you would have made Shawyer's Design Factor available to the forum). What was expected from Shawyer, the author of the equation, is to produce his equation: to answer "this is my equation:..." (defining the Design Factor and its variables, and not resorting to references where the variables are not explicitly defined). Instead, his response, relayed through you as a messenger, communicating behind a curtain, is an unconstructive response: Shawyer's Design Factor equation is never provided. Certainly not provided to this forum (was his equation provided instead to you in private?). Not a response one would expect in an Engineering or a Scientific journal, where the editors expect disclosure (and hence a definition) of what is being discussed (in this case what is Shawyer's Design Factor equation ?) before asserting that somebody's interpretation is wrong. This response stands in direct contrast to the direct, constructve responses of others: Paul March (NASA) who consistently provided geometrical dimensions, defined variables, and provided honest answers to honest questions. Same for Prof. McCulloch who answered questions directly (not using messengers) both in this forum and in his blog, instead of keeping obscure what are his equations.I look forward to your providing to this forum what is Shawyer's Design Factor equation (and then we can have a discussion of my effort to ascertain Shawyer's Design Factor, vis-ŕ-vis Shawyer's previous papers that I had to rely on).I also look forward to Shawyer providing the big and small diameters and the length of the truncated cones used in his experiments, so that this forum can verify the claims being made in his papers regarding the validity of his Design Factor (instead of having to rely on assessing dimensions from photographs, or resorting to parametrization of variables over a whole range, as NASA had to do to guess Shawyer's dimensions).
Hi Roger,I have posted your email to the forum and agree working with high power anything can be dangerous. Your warning is very timely as others are buying magnetrons and screwing them to homemade cavities.My approach is to use a programmable Rf generator (with programmable output level), connected to a max 20W Rf amp and SLOWLY increase the power applied as I vary the Rf frequency to parametrise the cavities characteristics. My cavity and Rf amplifier will be inside a tight Alum mesh 6 sided Faraday Cage (FC) to ensure no energy gets out to cause any problems. Even with the FC in place, I don't plan on getting any closer than 2 meters when it is powered on. Like you I have seen what high power and high voltage in high Q circuits can do.As I really don't like working with bad data nor reinventing the wheel, would you please send me your Df equation in either excel or just as a corrected formula in the form below.This would really help me understand the dynamics occurring inside a cavity as the applied Rf versus the Df derived from that frequency and cavity dimensions vary.If I understand you correctly, no matter what the frequency nor cavity dimensions, the calculated Df should always be in the range 0 - 1 even if the small end diameter is below the cutoff frequency? In the Rodal version, if I set a really large big diameter, a really large length, small diameter to 0.299705m, the Df does = 1.0000 at 1GHz but will go above 1 if the small end diameter is less than the frequency wavelength (less than 0.299705m at 1GHz). Should that not happen?Cl = cavity lengthCb = cavity big end diameterCs = cavity small end diameterf = applied frequencyc = light speed in selected mediumDf = 2c * (Cl^2) * SQRT(4 + (c / (Cl * f))^2) * f * (Cb - Cs) / (4 * Cb * Cs * (Cl * f)^2 + (c^2) * (Cb * Cs - (2 * Cl)^2))