Quote from: flux_capacitor on 07/25/2015 10:08 pmFrom the intro in the abstract paper:How can Tajmar says:QuoteAfter developing a numerical model to properly design our cavity for high efficiencies in close cooperation with the EM Drive's inventorand then measure:QuoteDue to a low Q factor of <50Why was the Q so desperately low? What could possibly have gone wrong with all those experts onboard and Dresden leading-edge technologies?Take a look at my prior posts (the ones were I suggested questions for Dr. Bagelbytes to ask). I think that there was gross overcoupling.Perhaps intentional to the magnetron's bandwidth.
From the intro in the abstract paper:How can Tajmar says:QuoteAfter developing a numerical model to properly design our cavity for high efficiencies in close cooperation with the EM Drive's inventorand then measure:QuoteDue to a low Q factor of <50Why was the Q so desperately low? What could possibly have gone wrong with all those experts onboard and Dresden leading-edge technologies?
After developing a numerical model to properly design our cavity for high efficiencies in close cooperation with the EM Drive's inventor
Due to a low Q factor of <50
Tajmar Experimental resultsCavity Length(m) = 0.0686Big Diameter(m) = 0.0541Small Diameter(m) = 0.0385
The Q is a major question mark why so low and you might be right on the coupling or placement of insertion, but still no air filled cavity in vacuum and we still see the major difference in vacuum and air.Shell
Quote from: WarpTech on 07/25/2015 09:26 pmI appreciate the help. Now i understand the issue. However, wouldn't a ray-vector approach show the same behavior without the need for spherical harmonics?Below is what Zeng & Fan wrote for impedances. Impedance is basically u0*velocity. The TE mode is the phase velocity, the TM mode is the group velocity. How do we plot this as a function of kr? I can't interpret something I don't understand and this just looks like gibberish to me, without some way to plot it out and visualize it. Sorry, I'm an engineer not a mathematician. ToddI think they are Henkel spherical functions. I could plot it with Mathematica but I have some $$$ work to do. Didn't Zeng and Fan have some plots of impedance in their paper?
I appreciate the help. Now i understand the issue. However, wouldn't a ray-vector approach show the same behavior without the need for spherical harmonics?Below is what Zeng & Fan wrote for impedances. Impedance is basically u0*velocity. The TE mode is the phase velocity, the TM mode is the group velocity. How do we plot this as a function of kr? I can't interpret something I don't understand and this just looks like gibberish to me, without some way to plot it out and visualize it. Sorry, I'm an engineer not a mathematician. Todd
Quote from: dustinthewind on 07/25/2015 06:44 pmQuote from: RonM on 07/25/2015 03:48 pmQuote from: Notsosureofit on 07/25/2015 03:34 pmQuote from: RonM on 07/25/2015 03:15 pmI agree. By accepted theory, there should be no thrust whatsoever beyond a photon rocket. If there really is verifiable excess thrust, no matter how small, then this a breakthrough.If by accepted theory you include General Relativity, then there should be a small thrust as long as you can accept some deviation from perfectly "flat" space. (the swimming spaceman was a good example)Good point, but I believe conventional wisdom is that space is flat. Of course, conventional wisdom could be wrong. If space isn't perfectly flat, then maybe we are on to something that would make a good drive for spaceflight. Still, no flying cars. space time is only flat where there is no gravity. This is why light follows a curved path in the presence of a gravitational well. http://www.math.brown.edu/~banchoff/STG/ma8/papers/dstanke/Project/curved_space.htmlIf you can artificially engineer a gravitational well of sorts, "maybe not exactly gravity but mimic it at a specific frequency", then you might be able to effectively curve space and time/energy at that particular wavelength. Spacetime is curved in the presence of gravity but all measurements up to now is that space itself (not spacetime) is Euclidean flat. RonM's statement was that space is (Euclidean) flat. He is correct.Experimental data from various, independent sources (WMAP, BOOMERanG and Planck for example) confirm that the universe is flat with only a 0.4% margin of error.https://en.wikipedia.org/wiki/Shape_of_the_universe#Curvature_of_UniverseThis is an important distinction.Spacetime should not be confused with space.
Quote from: RonM on 07/25/2015 03:48 pmQuote from: Notsosureofit on 07/25/2015 03:34 pmQuote from: RonM on 07/25/2015 03:15 pmI agree. By accepted theory, there should be no thrust whatsoever beyond a photon rocket. If there really is verifiable excess thrust, no matter how small, then this a breakthrough.If by accepted theory you include General Relativity, then there should be a small thrust as long as you can accept some deviation from perfectly "flat" space. (the swimming spaceman was a good example)Good point, but I believe conventional wisdom is that space is flat. Of course, conventional wisdom could be wrong. If space isn't perfectly flat, then maybe we are on to something that would make a good drive for spaceflight. Still, no flying cars. space time is only flat where there is no gravity. This is why light follows a curved path in the presence of a gravitational well. http://www.math.brown.edu/~banchoff/STG/ma8/papers/dstanke/Project/curved_space.htmlIf you can artificially engineer a gravitational well of sorts, "maybe not exactly gravity but mimic it at a specific frequency", then you might be able to effectively curve space and time/energy at that particular wavelength.
Quote from: Notsosureofit on 07/25/2015 03:34 pmQuote from: RonM on 07/25/2015 03:15 pmI agree. By accepted theory, there should be no thrust whatsoever beyond a photon rocket. If there really is verifiable excess thrust, no matter how small, then this a breakthrough.If by accepted theory you include General Relativity, then there should be a small thrust as long as you can accept some deviation from perfectly "flat" space. (the swimming spaceman was a good example)Good point, but I believe conventional wisdom is that space is flat. Of course, conventional wisdom could be wrong. If space isn't perfectly flat, then maybe we are on to something that would make a good drive for spaceflight. Still, no flying cars.
Quote from: RonM on 07/25/2015 03:15 pmI agree. By accepted theory, there should be no thrust whatsoever beyond a photon rocket. If there really is verifiable excess thrust, no matter how small, then this a breakthrough.If by accepted theory you include General Relativity, then there should be a small thrust as long as you can accept some deviation from perfectly "flat" space. (the swimming spaceman was a good example)
I agree. By accepted theory, there should be no thrust whatsoever beyond a photon rocket. If there really is verifiable excess thrust, no matter how small, then this a breakthrough.
Quote from: Rodal on 07/25/2015 10:10 pmQuote from: flux_capacitor on 07/25/2015 10:08 pmFrom the intro in the abstract paper:How can Tajmar says:QuoteAfter developing a numerical model to properly design our cavity for high efficiencies in close cooperation with the EM Drive's inventorand then measure:QuoteDue to a low Q factor of <50Why was the Q so desperately low? What could possibly have gone wrong with all those experts onboard and Dresden leading-edge technologies?Take a look at my prior posts (the ones were I suggested questions for Dr. Bagelbytes to ask). I think that there was gross overcoupling.Perhaps intentional to the magnetron's bandwidth.Not sure if it was overcoupling. But the magnetron only outputted 2.4ghz. They would have needed something that outputed 3Ghz to get a higher Q
With such small thrust and the apparatus not being self-contained, I am wary to break out any champagne here.
And here is the COMOSOL plot.
Quote from: birchoff on 07/25/2015 09:14 pmTajmar Experimental resultsCavity Length(m) = 0.0686Big Diameter(m) = 0.0541Small Diameter(m) = 0.0385Ugh... This thruster is teeny. Like half a shot glass. Edit: corrected cut
Quote from: Prunesquallor on 07/25/2015 10:32 pmQuote from: birchoff on 07/25/2015 09:14 pmTajmar Experimental resultsCavity Length(m) = 0.0686Big Diameter(m) = 0.0541Small Diameter(m) = 0.0385Ugh... This thruster is teeny. Like half a shot glass. Edit: corrected cutDr. Rodal - using your exact solution, what is the resonant frequency of this cavity?And does that huge waveguide hanging off the side make the device something other than a conical frustum? Looks like different geometry to me.aero
Excellent point. I should analyze that when I have a chance. Now I have to have a couple of beers , a Martini, to join Ron M
Quote from: Rodal on 07/25/2015 07:58 pmQuote from: dustinthewind on 07/25/2015 06:44 pmQuote from: RonM on 07/25/2015 03:48 pmQuote from: Notsosureofit on 07/25/2015 03:34 pmQuote from: RonM on 07/25/2015 03:15 pmI agree. By accepted theory, there should be no thrust whatsoever beyond a photon rocket. If there really is verifiable excess thrust, no matter how small, then this a breakthrough.If by accepted theory you include General Relativity, then there should be a small thrust as long as you can accept some deviation from perfectly "flat" space. (the swimming spaceman was a good example)Good point, but I believe conventional wisdom is that space is flat. Of course, conventional wisdom could be wrong. If space isn't perfectly flat, then maybe we are on to something that would make a good drive for spaceflight. Still, no flying cars. space time is only flat where there is no gravity. This is why light follows a curved path in the presence of a gravitational well. http://www.math.brown.edu/~banchoff/STG/ma8/papers/dstanke/Project/curved_space.htmlIf you can artificially engineer a gravitational well of sorts, "maybe not exactly gravity but mimic it at a specific frequency", then you might be able to effectively curve space and time/energy at that particular wavelength. Spacetime is curved in the presence of gravity but all measurements up to now is that space itself (not spacetime) is Euclidean flat. RonM's statement was that space is (Euclidean) flat. He is correct.Experimental data from various, independent sources (WMAP, BOOMERanG and Planck for example) confirm that the universe is flat with only a 0.4% margin of error.https://en.wikipedia.org/wiki/Shape_of_the_universe#Curvature_of_UniverseThis is an important distinction.Spacetime should not be confused with space.Does the 0.4% margin of error in space being Euclidean flat leave enough room for a General Relativity explanation of EM drive thrust?
Quote from: deltaMass on 07/25/2015 10:37 pmWith such small thrust and the apparatus not being self-contained, I am wary to break out any champagne here.I'll drink a couple of beers to it. Then again, I was planning on doing that tonight anyway. Still, the results are positive. There's more work to do to figure out what is or is not going on....
This graph clearly shows that the group velocity for small kr is faster than light.