......I'm shooting for TE112 first shot but meep is a little lacking using an antenna other than the placements. Have a few ideas other than just throwing the antenna in the cavity.Wasn't aero going to try to excite a mode in the side wall with a snub center to top and bottom today with the itsybitsy cavity? It was also suggested that a square pad could be made simulating a loop that could excite a TE mode, wonder what happened to that line of thought?Thanks for the feedback, it was helpful.Shell
Quote from: rfmwguy on 07/28/2015 12:27 amSpaceflight. I've avoided useage of the term without enough ground test results, but it might be time to plant a seed of discussion for the future considering Tajmar's paper. We will need to think about electric power for a smallsat. That will not be easy.A magnetron is not 100% efficient, meaning that this type of device would require north of 1kW of electric power. This is not easily attainable on a satellite. RTGs are usually much below this.:https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generatorSolar panels appear to be the best choice at levels above 1kW:https://en.wikipedia.org/wiki/Solar_panels_on_spacecraftSo dreams of deep space travel might look like this: Solar Panels to ? AU, jetison, then RTG takeover when out of solar influence. IOW, a hybrid power design. Moral of story, optimize for max performance to weight ratio/effeciency. Partner with solar panel and/or RTG provider. Agreed on solar power for inside the asteroid belt. However, What do you think abuot fuel cells?
Spaceflight. I've avoided useage of the term without enough ground test results, but it might be time to plant a seed of discussion for the future considering Tajmar's paper. We will need to think about electric power for a smallsat. That will not be easy.A magnetron is not 100% efficient, meaning that this type of device would require north of 1kW of electric power. This is not easily attainable on a satellite. RTGs are usually much below this.:https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generatorSolar panels appear to be the best choice at levels above 1kW:https://en.wikipedia.org/wiki/Solar_panels_on_spacecraftSo dreams of deep space travel might look like this: Solar Panels to ? AU, jetison, then RTG takeover when out of solar influence. IOW, a hybrid power design. Moral of story, optimize for max performance to weight ratio/effeciency. Partner with solar panel and/or RTG provider.
Quote from: SeeShells on 07/28/2015 12:47 am......I'm shooting for TE112 first shot but meep is a little lacking using an antenna other than the placements. Have a few ideas other than just throwing the antenna in the cavity.Wasn't aero going to try to excite a mode in the side wall with a snub center to top and bottom today with the itsybitsy cavity? It was also suggested that a square pad could be made simulating a loop that could excite a TE mode, wonder what happened to that line of thought?Thanks for the feedback, it was helpful.ShellDid you notice my post where I wrote that the Wolfram Mathematica / Meep runs reveal that SeeShells was right that having the lateral antenna at the big end is better than at the small end for Yang/Shell?Unfortunately so far we only know this for TM modes (since TE modes cannot be excited by a dipole antenna). aero is running rfmwguy with the antenna at the big end. We'll see whether what we found for Yang/Shell is also the case for NSF-1701.____PS: I thought you were shooting for TE012 instead of TE112.
I show the calculated TE111 Electric Field in theta polar direction for Tajmar's TU Dresden University EM Drive, to compare it with his COMSOL FEA calculationAssumed dimensions:Big diameter = 0.1062 m = (2*0.0541m - 0.002 m)Small diameter = 0.075 m = (2*0.0385 m - 0.002 m)Axial Length = 0.100842 m = 0.735*2*0.0686 mAs per TheTraveller I have subtracted 2 mm for copper thickness from the external dimensions, however this has a negligible influence on the resultsThe axial internal length is 73.5% of the exterior length (it is adjusted internally with a screw prior to testing)TE111 Natural frequency = 2.446 GHzI enclose strictly for discussion, research and illustration purposes Fig. 2 a of Tajmar et.al. COMSOL FEA analysis for comparison with my calculations “…for purposes such as criticism, comment, news reporting, scholarship, or research…” under US Fair Usehttp://fairuse.stanford.edu/overview/fair-use/what-is-fair-use/This is the American Institute of Aeronautics and Astronautics link to Martin Tajmar's et.al. paper, that should be obtained from the American Institute of Aeronautics and Astronautics:Direct Thrust Measurements of an EM Drive and Evaluation of Possible Side-Effects M. Tajmar and G. Fiedler51st AIAA/SAE/ASEE Joint Propulsion Conference http://arc.aiaa.org/doi/pdf/10.2514/6.2015-4083
Quote from: birchoff on 07/28/2015 12:47 amQuote from: rfmwguy on 07/28/2015 12:27 amSpaceflight. I've avoided useage of the term without enough ground test results, but it might be time to plant a seed of discussion for the future considering Tajmar's paper. We will need to think about electric power for a smallsat. That will not be easy.A magnetron is not 100% efficient, meaning that this type of device would require north of 1kW of electric power. This is not easily attainable on a satellite. RTGs are usually much below this.:https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generatorSolar panels appear to be the best choice at levels above 1kW:https://en.wikipedia.org/wiki/Solar_panels_on_spacecraftSo dreams of deep space travel might look like this: Solar Panels to ? AU, jetison, then RTG takeover when out of solar influence. IOW, a hybrid power design. Moral of story, optimize for max performance to weight ratio/effeciency. Partner with solar panel and/or RTG provider. Agreed on solar power for inside the asteroid belt. However, What do you think abuot fuel cells?A little unclear on those babies. You might have to upskill me a bit.
Agreed on solar power for inside the asteroid belt. However, What do you think abuot fuel cells?
Quote from: birchoff on 07/28/2015 12:47 amAgreed on solar power for inside the asteroid belt. However, What do you think abuot fuel cells?Fuel cells may have a use for powering aircraft on oxygen free places like Venus.
Wasn't aero going to try to excite a mode in the side wall with a snub center to top and bottom today with the itsybitsy cavity? It was also suggested that a square pad could be made simulating a loop that could excite a TE mode, wonder what happened to that line of thought?
Quote from: mrseanpaul81 on 07/27/2015 09:20 pmQuote from: SeeShells on 07/27/2015 06:57 pmQuote from: mittelhauser on 07/27/2015 05:06 pmQuote from: TheTraveller on 07/27/2015 06:58 amQuote from: demofsky on 07/27/2015 06:30 amThe device used by Tajmar looks more like a version of Shawyer's first fustrum than the latest work by Yang, et al. It would be very nice if we could get actual schematics of Tajmar's fustrum rather than squinting at pictures trying to figure out what he did...<clip>So if you or one of your friends within that 50 mile radius want to put a couple bucks to help not to make more millions but because they choose to dream, I'll welcome it.ShellI am game. Maybe you can get a kickstarter togetger. I would contribute and I am sure more people would tooIt's at the bottom of my post under Crazy Eddie is getting a little more crazy. Thank You!!
Quote from: SeeShells on 07/27/2015 06:57 pmQuote from: mittelhauser on 07/27/2015 05:06 pmQuote from: TheTraveller on 07/27/2015 06:58 amQuote from: demofsky on 07/27/2015 06:30 amThe device used by Tajmar looks more like a version of Shawyer's first fustrum than the latest work by Yang, et al. It would be very nice if we could get actual schematics of Tajmar's fustrum rather than squinting at pictures trying to figure out what he did...<clip>So if you or one of your friends within that 50 mile radius want to put a couple bucks to help not to make more millions but because they choose to dream, I'll welcome it.ShellI am game. Maybe you can get a kickstarter togetger. I would contribute and I am sure more people would too
Quote from: mittelhauser on 07/27/2015 05:06 pmQuote from: TheTraveller on 07/27/2015 06:58 amQuote from: demofsky on 07/27/2015 06:30 amThe device used by Tajmar looks more like a version of Shawyer's first fustrum than the latest work by Yang, et al. It would be very nice if we could get actual schematics of Tajmar's fustrum rather than squinting at pictures trying to figure out what he did...<clip>So if you or one of your friends within that 50 mile radius want to put a couple bucks to help not to make more millions but because they choose to dream, I'll welcome it.Shell
Quote from: TheTraveller on 07/27/2015 06:58 amQuote from: demofsky on 07/27/2015 06:30 amThe device used by Tajmar looks more like a version of Shawyer's first fustrum than the latest work by Yang, et al. It would be very nice if we could get actual schematics of Tajmar's fustrum rather than squinting at pictures trying to figure out what he did...
Quote from: demofsky on 07/27/2015 06:30 amThe device used by Tajmar looks more like a version of Shawyer's first fustrum than the latest work by Yang, et al. It would be very nice if we could get actual schematics of Tajmar's fustrum rather than squinting at pictures trying to figure out what he did...
The device used by Tajmar looks more like a version of Shawyer's first fustrum than the latest work by Yang, et al. It would be very nice if we could get actual schematics of Tajmar's fustrum rather than squinting at pictures trying to figure out what he did...
Quote from: A_M_Swallow on 07/28/2015 01:59 amQuote from: birchoff on 07/28/2015 12:47 amAgreed on solar power for inside the asteroid belt. However, What do you think abuot fuel cells?Fuel cells may have a use for powering aircraft on oxygen free places like Venus.http://www.lockheedmartin.com/us/products/compact-fusion.htmlLockheed Martin: Compact Fusion Research & Development at the Skunk Works is working on this and since we're talking about future tech I think this would scale quite well to space.
Random thoughts:A microwave oven Maggie, operating at 200C in a vacuum may out gas from its radiator. This could cause the appearance of something that looks like working mass, but isn't.Once again, the Edison Effect predates the discovery of the electron by over a decade. Who knows what we could be spitting out the business end... Has anyone considered a fractal antenna, to try and maximize the power dumped into the frustum?
2 comments I'd like to make:First: Solar power. The ISS arrays are about as big as you would want to build. With 80's solar cells they are good for about 30KW at 1 AU and beginning of life. The latest cells are about 3 times more efficient. If you used the same size arrays with the latest high efficiency cells you could eek out maybe 90-100KW per array or roughly 3/4 of a MW for something ISS sized. If you are in orbit, battery charging for night passes reduces usable power by over half. The arrays tend to be rather fragile as well. I think I'd rather hook an EM drive up to a nuclear reactor. ....
Quote from: DrLOAC on 07/28/2015 03:21 am2 comments I'd like to make:First: Solar power. The ISS arrays are about as big as you would want to build. With 80's solar cells they are good for about 30KW at 1 AU and beginning of life. The latest cells are about 3 times more efficient. If you used the same size arrays with the latest high efficiency cells you could eek out maybe 90-100KW per array or roughly 3/4 of a MW for something ISS sized. If you are in orbit, battery charging for night passes reduces usable power by over half. The arrays tend to be rather fragile as well. I think I'd rather hook an EM drive up to a nuclear reactor. ....This is exactly what I would have expected. Remember though that EM (and other electric) Drives are very gentle so it does not matter if a tug uses massive (monstrous?) arrays that are fragile. This thing will change course slowly and things will not fly off. They use chemical rockets on the ISS and so the stress is much higher.Edits: Clarification.