....I in particular am trying fervently to find a solution for an unloaded conical frustum geometry resonant at 2437mhz at TE111 to start with. 2450mhz is a good start. From there you can perturb the cavity down to 2437mhz at will (mostly trial and error)...
...I am still unsure if angle by the apex is truly important for resonance, but according to Egan, it is: http://www.gregegan.net/SCIENCE/Cavity/Cavity.html But if my hunch about the importance of the QV to spacetime is correct (pretty much has to be), 45 and 90 degrees by the apex is important. ..
I learned a new trick. Here are some images of the ez field along the x coordinate. The imaginary and real parts are shown at x=194, because that showed a powerful signal.The imaginary and real parts are shown at x=216, because that is the big end of the cavity.The imaginary and real parts are shown at x=39, because that is the just inside the dielectric at the small end.I'll see if I can get some magnetic field images.
I will try to get additional views as time and health permits. My boy brought something home from school and we've all contracted it. Unfortunately for me, I didn't throw it off like the wife and boy did. This image is in 3D, which means very low resolution, so no its not like the other one. It's the same cavity and same drive frequency though so it should be generally very similar.
Quote from: aero on 02/01/2015 06:57 pmI learned a new trick. Here are some images of the ez field along the x coordinate. The imaginary and real parts are shown at x=194, because that showed a powerful signal.The imaginary and real parts are shown at x=216, because that is the big end of the cavity.The imaginary and real parts are shown at x=39, because that is the just inside the dielectric at the small end.I'll see if I can get some magnetic field images.For these truncated cone calculations, you reported (in the movie attachment to http://forum.nasaspaceflight.com/index.php?topic=36313.msg1321460#msg1321460 ) that the value of the relative permittivity (dielectric constant) you used was 2.3.I did not find the value of relative permeability ( the degree of magnetization of the material ) you used for your truncated cone (NASA Brady et.al.) calculations.Just to be sure, could you please confirm that you used a value of 1 (one) for the relative permeability in the above calculations ?
Quote from: Rodal on 02/02/2015 02:10 pmQuote from: aero on 02/01/2015 06:57 pmI learned a new trick. Here are some images of the ez field along the x coordinate. The imaginary and real parts are shown at x=194, because that showed a powerful signal.The imaginary and real parts are shown at x=216, because that is the big end of the cavity.The imaginary and real parts are shown at x=39, because that is the just inside the dielectric at the small end.I'll see if I can get some magnetic field images.For these truncated cone calculations, you reported (in the movie attachment to http://forum.nasaspaceflight.com/index.php?topic=36313.msg1321460#msg1321460 ) that the value of the relative permittivity (dielectric constant) you used was 2.3.I did not find the value of relative permeability ( the degree of magnetization of the material ) you used for your truncated cone (NASA Brady et.al.) calculations.Just to be sure, could you please confirm that you used a value of 1 (one) for the relative permeability in the above calculations ? I used the dielectric constant of 1.76 for the dielectric disk. That number was 2.3 in the movie but I only use 1.76 now that I've decided that 1.76 is the correct value. To investigate resonance of an empty cavity I can replace the dielectric material with "air." The value is 1.76 for the above runs...
Quote from: Rodal on 02/02/2015 02:10 pmQuote from: aero on 02/01/2015 06:57 pmI learned a new trick. Here are some images of the ez field along the x coordinate. The imaginary and real parts are shown at x=194, because that showed a powerful signal.The imaginary and real parts are shown at x=216, because that is the big end of the cavity.The imaginary and real parts are shown at x=39, because that is the just inside the dielectric at the small end.I'll see if I can get some magnetic field images.For these truncated cone calculations, you reported (in the movie attachment to http://forum.nasaspaceflight.com/index.php?topic=36313.msg1321460#msg1321460 ) that the value of the relative permittivity (dielectric constant) you used was 2.3.I did not find the value of relative permeability ( the degree of magnetization of the material ) you used for your truncated cone (NASA Brady et.al.) calculations.Just to be sure, could you please confirm that you used a value of 1 (one) for the relative permeability in the above calculations ? ..." I do move the antenna location around and often forget to put it back to the most representative location for the run type. I move it because when I run Harminv using Cylindrical coordinates, the antenna must be on the central axis of rotation of the cone. If it is not, then in Cylindrical coordinates, nothing excites the cavity.
Quote from: Mulletron on 01/30/2015 06:40 pm...I am still unsure if angle by the apex is truly important for resonance, but according to Egan, it is: http://www.gregegan.net/SCIENCE/Cavity/Cavity.html But if my hunch about the importance of the QV to spacetime is correct (pretty much has to be), 45 and 90 degrees by the apex is important. ..@Mulletron, why do you think that the cone angle (thetaw in Egan's nomenclature), of an EM Drive, should (ideally) be 45 degrees ? (I don't recall the reasons(s), please refresh my mind).
"Currently have two ways to find the electromagnetic field of the rectangular and circular waveguides, the eigen-value equation which is an analytical method and numerical solution, when finding solution for the resonator, Maxwell equation in is need to be created in a spherical coordinate system, because the complexity of the spherical coordinate fielder equation, has not found anyone using eigen-value method to calculated the distribution of the resonant field. Only find in Paper [4] using asymptotic method for conical waveguide. That method assume a equivalent radius ae, believes field of wavefront sphere of cone waveguide Eo,EФ,Ho,HФ can use its wavefront position radius ae equivalent circular waveguide field Er,EФ,Hr,HФ, this method of finding the field distribution within the conical resonator can be used as reference, but the accuracy reduced as the cone half opening angle increases. Using finite element to numerically simulate the Maxwell electromagnetic equation for the idealised conical resonator, the distribution of electromagnetic can be obtained directly, this method is not limited by the cavity structure and microwave mode."
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.
(*"Shawyer EXPERIMENTAL geometry"shawyerExpLength=0.156 meter;shawyerExpBigDiameter=0.16 metershawyerExpSmallDiameter=0.127546 meter;*)(*" Shawyer DEMO geometry"shawyerDemoLength=0.345 meter;shawyerDemoBigDiameter=0.28 meter;shawyerDemoSmallDiameter=0.128853 meter;*)
Quote from: Rodal on 01/31/2015 03:20 pm(*"Shawyer EXPERIMENTAL geometry"shawyerExpLength=0.156 meter;shawyerExpBigDiameter=0.16 metershawyerExpSmallDiameter=0.127546 meter;*)(*" Shawyer DEMO geometry"shawyerDemoLength=0.345 meter;shawyerDemoBigDiameter=0.28 meter;shawyerDemoSmallDiameter=0.128853 meter;*)These were both 2450mhz experiments. Where did the small diameters and lengths come from? I see the Large diameters here: http://www.emdrive.com/yang-juan-paper-2012.pdf.
Suppose that there was a box with hypothetical 100% reflecting internal walls. It would be possible to trap some light energy in such a box. A freely propagating photon is a massless particle, but what about a “confined photon” trapped in the box. That photon is forced to have the box’s specific frame of reference. A calculation at the end of chapter 1 shows that the photon pressure exerted on the walls of the box is uniform if the box is not accelerating, but the pressure becomes unequal if the box is accelerated. This difference in pressure results in a net force which resists acceleration. This is the inertia of the confined photon energy and it exactly equals the inertia of an equal amount of energy in the form of matter particles. This is not a coincidence.
.......the photon pressure exerted on the walls of the box is uniform if the box is not accelerating, but the pressure becomes unequal if the box is accelerated. This difference in pressure results in a net force which resists acceleration.
A photon trapped in such a cavity behaves as if it had mass; in other words, the cavity creates a "trapping potential," keeping the photons from escaping.
However, if light is trapped in a box with perfect mirrors so the photons are continually reflected back and forth in both directions symmetrically in the box, then the total momentum is zero in the box's frame of reference but the energy is not. Therefore the light adds a small contribution to the mass of the box.
....Keeping first principles in mind concerning the QV model for how these thrusters may work. If they do interact with the QV somehow, their design should obviously be complimentary to the geometry of spacetime (there are crazy folks out there http://www.onlyspacetime.com/, I'm one of them, who believe spacetime emerges from the quantum world.) I wanted to test whether opening angle had any significance. When faced with choosing an opening angle amongst seemingly arbitrary angles I've found amongst Shawyer's prototypes, I wondered if a light cone opening angle of 45 degrees (measured from the longitudinal axis for a total of 90 as measured from outside) would be of any benefit or not. http://en.wikipedia.org/wiki/Minkowski_diagram After seeing that a light cone setup would be a ginormous cone after factoring in the necessary conical sections for front and end walls, I further halved it to 22.5 degrees (total of 45). That's why I have 2 drawn up in CAD. So it really came down to a question of what angle to pick out of so many choices. Those two I want to try. Trying to reconcile the above ideas with simultaneously hunting a viable rf solution is proving daunting. Mostly due to the lack of resources. I may not be afforded the option to choose an opening angle and stay on freq and within reasonable size limits. As I'm researching this it is becoming clear that opening angle will be dominated by chosen frequency and practical considerations.After following up on Aero's post: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1274400#msg1274400 about this: http://www.emdrive.com/NWPU2010translation.pdf trying to see if I can find a good solution for calculating exact solutions for conical frustums, I learned that no such method exists to find closed form solutions to that problem. The Egan method is similar to what we need but it doesn't address the problem. None of what we're dealing here has spherical end caps. And honestly, the Egan way is way too high speed for me.Quote"Currently have two ways to find the electromagnetic field of the rectangular and circular waveguides, the eigen-value equation which is an analytical method and numerical solution, when finding solution for the resonator, Maxwell equation in is need to be created in a spherical coordinate system, because the complexity of the spherical coordinate fielder equation, has not found anyone using eigen-value method to calculated the distribution of the resonant field. Only find in Paper [4] using asymptotic method for conical waveguide. That method assume a equivalent radius ae, believes field of wavefront sphere of cone waveguide Eo,EФ,Ho,HФ can use its wavefront position radius ae equivalent circular waveguide field Er,EФ,Hr,HФ, this method of finding the field distribution within the conical resonator can be used as reference, but the accuracy reduced as the cone half opening angle increases. Using finite element to numerically simulate the Maxwell electromagnetic equation for the idealised conical resonator, the distribution of electromagnetic can be obtained directly, this method is not limited by the cavity structure and microwave mode."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.They're basically saying: (1) That I'm hosed trying to calculate such things. Simulating the conical frustum using FEM software is the way to go. Which I simply don't have access to. (2) Also they're saying that as the opening angle opens up, approximating the resonant modes becomes more and more difficult. (3) You have to shorten the cavity height as opening angle increases to maintain resonance at desired frequency, but it lowers Q. So I should probably (for now) re-think using such wide opening angles.So I'm switching gears a bit using what I've learned from the above reporting. (1) Keeping Cannae in mind, who says we need a cone anyway? We've discussed the commonality between Shawyer and Cannae in thread 1. http://forum.nasaspaceflight.com/index.php?topic=29276.msg1298712#msg1298712 So I'm thinking it would be smart to use what we've learned about cylinders and try a cylinder experiment.(2) Instead of trying to optimize right out of the gate by throwing around light cones. It would be smarter to use the dims we already have for Shawyer experimental and demo, which you provided on the previous page.(3) If I ever get this build going, I'm going to have to easter egg it anyway using a sig-gen and a power meter to find the resonant frequency (treat it like a filter, tune it until I get get an output from sample port), so I don't need to have exact calculations. I just need to be close enough to be within tunable limits.