Quote from: space_britannia on 06/18/2015 02:33 pmApologies if this has already been raised, but this paper on propulsion of a graphene sponge by electron ejection (excited by a laser) has been doing the rounds: http://nextbigfuture.com/2015/05/graphene-sponge-can-absorb-light-and.htmlHave any attempts been made to measure an electron plume from the EmDrive? Are the devices building up a charge?Concerning charge, see this : http://forum.nasaspaceflight.com/index.php?topic=37642.msg1390599#msg1390599
Apologies if this has already been raised, but this paper on propulsion of a graphene sponge by electron ejection (excited by a laser) has been doing the rounds: http://nextbigfuture.com/2015/05/graphene-sponge-can-absorb-light-and.htmlHave any attempts been made to measure an electron plume from the EmDrive? Are the devices building up a charge?
...(set! fsi 3.87295489E+009) ; Drive frequencyNot a lot of CPU time at all. Two to 5 minutes, depending on noise BW....Yes, its the same machine.There's also the question of where the antenna should be located and should it be excited by Ez (currently) or by Hy components?
Cavity Length (m) big diameter (m) small diameter (m)0.1386 0.2314 0.1257Congratulations on making such great progress with MEEP where you can now run 3D models. Additionally, there is the issue of what the excitation RF frequency was. In Shaywer's publications, Shawyer gives 3.85 GHz for the Flight Thruster, but in that quotation TheTraveller is saying that External Rf was instead 3.90 GHz?What excitation frequency did you use for your MEEP 3 D analysis ? (3.85 GHz or 3.90 GHz ?)How much computer time do these MEEP 3D runs take ?Are you running them on the same computer that you were using to run the MEEP 2D models ?There's also the question of where the antenna should be located and should it be excited by Ez (currently) or by Hy components?
Quote from: aero on 06/18/2015 03:12 pm...(set! fsi 3.87295489E+009) ; Drive frequencyNot a lot of CPU time at all. Two to 5 minutes, depending on noise BW....Yes, its the same machine.There's also the question of where the antenna should be located and should it be excited by Ez (currently) or by Hy components?That's fantastic, I recall when people where suggesting using a more powerful machine or to do your calculations in the cloud !!!QUESTION1: Is your solution an eigenvalue (frequency) solution (using the MEEP frequency solver)?QUESTION2: Can you attempt to also perform a time -marching solution, to see the time-decaying effect of evanescent waves and other effects that Warp-Tech, Shell and myself are interested in? (Such a solution will take much more computer time of course, and you will have to use a time step small enough to satisfy stability of the central difference scheme)I still don't see the motivation for me to re-run calculations for slightly different dimensions and slightly different frequencies for the Flight Thruster, based on unpublished numbers that contradict what Shawyer published (3.85 GHz for the Flight Thruster) but you if you are interested in further exercising MEEP, you could try what TheTraveller is suggesting. I'm not clear as to what are the dimensions that go with the 3.90.......GHz frequency, you may have to obtain that directly from him. And I am still not clear as to whether the Flight Thruster has spherical ends or flat ends, and all the other questions regarding antenna placement, etc.
...I guess you are having a bad day as you seem to be getting confused.I supplied my estimated Flight Thruster dimensions to Shawyer and asked him what would be the resonant frequency. He replied 3.9003GHz. So my estimated dimensions were close to those of the Flight Thruster's 3.85GHz but not spot on. How can you NOT be clear as I have stated this now many times??? It would seem you do not read what I post???Shawyer has stated the Flight Thruster has Spherical ends and a Q of 50,000. Do you read any of what he has published?All I see is more hand waving as you seem to be determined to NOT post what your method produces for resonance at my estimated dimensions.
Quote from: Rodal on 06/18/2015 03:42 pmQuote from: aero on 06/18/2015 03:12 pm...(set! fsi 3.87295489E+009) ; Drive frequencyNot a lot of CPU time at all. Two to 5 minutes, depending on noise BW....Yes, its the same machine.There's also the question of where the antenna should be located and should it be excited by Ez (currently) or by Hy components?That's fantastic, I recall when people where suggesting using a more powerful machine or to do your calculations in the cloud !!!QUESTION1: Is your solution an eigenvalue (frequency) solution (using the MEEP frequency solver)?QUESTION2: Can you attempt to also perform a time -marching solution, to see the time-decaying effect of evanescent waves and other effects that Warp-Tech, Shell and myself are interested in? (Such a solution will take much more computer time of course, and you will have to use a time step small enough to satisfy stability of the central difference scheme)I still don't see the motivation for me to re-run calculations for slightly different dimensions and slightly different frequencies for the Flight Thruster, based on unpublished numbers that contradict what Shawyer published (3.85 GHz for the Flight Thruster) but you if you are interested in further exercising MEEP, you could try what TheTraveller is suggesting. I'm not clear as to what are the dimensions that go with the 3.90.......GHz frequency, you may have to obtain that directly from him. And I am still not clear as to whether the Flight Thruster has spherical ends or flat ends, and all the other questions regarding antenna placement, etc.I guess you are having a bad day as you seem to be getting confused.I supplied my estimated Flight Thruster dimensions to Shawyer and asked him what would be the resonant frequency. He replied 3.9003GHz. So my estimated dimensions were close to those of the Flight Thruster's 3.85GHz but not spot on. How can you NOT be clear as I have stated this now many times??? It would seem you do not read what I post???Shawyer has stated the Flight Thruster has Spherical ends and a Q of 50,000. Do you read any of what he has published?All I see is more hand waving as you seem to be determined to NOT post what your method produces for resonance at my estimated dimensions.
He's not replying to you with the full solution because doing this calculation properly takes time. Both the thinking time and the compute time. You should try to solve some problems with a FEM solver instead of walking out some kludgy guided wavelength thing. You should be extremely content with the fact that Rodal has continued to reply and be civil with you as 99.9% of the people in the EM measurement industry would have just given up and disappeared once you started pushing clearly wrong computation so aggressively.
Quote from: aero on 06/18/2015 03:12 pm...(set! fsi 3.87295489E+009) ; Drive frequencyNot a lot of CPU time at all. Two to 5 minutes, depending on noise BW....Yes, its the same machine.There's also the question of where the antenna should be located and should it be excited by Ez (currently) or by Hy components?That's fantastic, I recall when people where suggesting using a more powerful machine or to do your calculations in the cloud !!!QUESTION1: Is your solution an eigenvalue (frequency) solution (using the MEEP frequency solver)?QUESTION2: Can you attempt to also perform a time -marching solution, to see the time-decaying effect of evanescent waves and other effects that Warp-Tech, Shell and myself are interested in? (Such a solution will take much more computer time of course, and you will have to use a time step small enough to satisfy stability of the central difference scheme) ... snip ...
Please Mr. Traveller be more civil. I love this debate, but there is no need for this kind of attitude. Dr. Rodal means no harm. In fact this debate has such high standard thanks to him and other scientist. Let get back to the civil side of debate, where we respect each others ideas. Your ideas are great too.With kind regards. Your EmDrive followers.
Blaine wrote an hour ago Okay, this is clearly not working as a reliable method of testing for you guys. But, do you have another plan? Use oil if you continue with this method. Apparently, that would help a lot according to Rodal.movax wrote 7 minutes ago Yes. We will put it on a swimming platform, stabilized by a ring magnet on the ground an another one under the platform.What does anyone think of the teams idea? Of his idea?
Quote from: aero on 06/18/2015 03:12 pm...(set! fsi 3.87295489E+009) ; Drive frequencyNot a lot of CPU time at all. Two to 5 minutes, depending on noise BW....Yes, its the same machine.There's also the question of where the antenna should be located and should it be excited by Ez (currently) or by Hy components?That's fantastic, I recall when people where suggesting using a more powerful machine or to do your calculations in the cloud !!!QUESTION1: Is your solution an eigenvalue (frequency) solution (using the MEEP frequency solver)?QUESTION2: Can you attempt to also perform a time -marching solution, to see the time-decaying effect of evanescent waves and other effects that Warp-Tech, Shell and myself are interested in? (Such a solution will take much more computer time of course, and you will have to use a time step small enough to satisfy stability of the central difference scheme)snip
...I would be back to the need for a more powerful machine as soon as I increased the computational lattice looking for any RF energy outside of the cavity. (like modeling a screen end, instead of a solid plate) By using a totally enclosed cavity with quarter inch perfect metal skin, I'm not concerned with Meep detecting anything external to the cavity....
Quote from: Chrochne on 06/18/2015 05:01 pmPlease Mr. Traveller be more civil. I love this debate, but there is no need for this kind of attitude. Dr. Rodal means no harm. In fact this debate has such high standard thanks to him and other scientist. Let get back to the civil side of debate, where we respect each others ideas. Your ideas are great too.With kind regards. Your EmDrive followers.I have asked many times for the calcs. We need to establish if Dr Rodal's method can actually compute the resonate frequency for the real life Flight Thruster. People are starting to build EM Drives. They need to know their dimensions will achieve resonance or they will see NO THRUST.Knowing a DIYers dimensions will get resonance with their Rf gen is critical as most have very little ability to change frequency.We have ONE real world example of internal dimension to resonance frequency, yet no one seems to understand the significance of those SPR supplied numbers. Having Dr Rodal verify his method gives the same value is critical to anyone using his numbers.If you use dimensions that do not produce resonance you will get NO thrust, then you will stop and the EM Drive will get a bad name.Of everything you can do, in building a EM Drive, getting dimensions that will produce resonance with your Rf gen is the most critical step. That is why I was SO HAPPY when SPR give me the resonance of my estimated Flight Thruster dimensions, cause I could then verify my SS generated the same result.I really can't understand why Dr Rodal is not revealing his Flight Thruster resonance frequency. Surely he wants to generate good data, so DIYers can go forward, with faith their Rf generators and frustum dimensions will achieve the resonance he has predicted?
...Considering these simple facts I've decided to make my Frustum(s) so that it will be able to change the internal dimensions to fine tune from my own best estimate and this is why I plan on building 3 different frustums and all will be adjustable. I stated designing the flexibility in my first one when I joined this group. ...
Quote from: Rodal on 06/18/2015 03:42 pmQuote from: aero on 06/18/2015 03:12 pm...I would be back to the need for a more powerful machine as soon as I increased the computational lattice looking for any RF energy outside of the cavity. (like modeling a screen end, instead of a solid plate) By using a totally enclosed cavity with quarter inch perfect metal skin, I'm not concerned with Meep detecting anything external to the cavity.My solution is still the same Harminv generated answers. Harminv does seem to work a little better in 3D, at least it is easier to find resonance in my current setup. In order to use the frequency solver, I think I would need to recompile and install meep from source. I'm still running the binary downloaded from the Debian web site. This is an older version and I don't think it includes the frequency solver, unless you are referming to MPB, then I know that requires a compile from source in order to install it.I generate the time solution with every run. It only adds the time needed to output the data files which is not much. My problem is converting the 4D data set then piecing it together. In particular the colors usually come out very weak and faded so there is not a lot to see. That is because the field strength near the antenna is high, while it is low in the areas of interest. This becomes a scaling problem for the color map. If I get a good set of images I will send them off to Tom Ligon who is good enough to convert them to a movie, then I will post the movie. But don't hold your breath.Enclose your model with a larger model and thereby limiting the number of calculations and keep the this walls?Just a thought.Shell
Quote from: aero on 06/18/2015 03:12 pm...I would be back to the need for a more powerful machine as soon as I increased the computational lattice looking for any RF energy outside of the cavity. (like modeling a screen end, instead of a solid plate) By using a totally enclosed cavity with quarter inch perfect metal skin, I'm not concerned with Meep detecting anything external to the cavity.My solution is still the same Harminv generated answers. Harminv does seem to work a little better in 3D, at least it is easier to find resonance in my current setup. In order to use the frequency solver, I think I would need to recompile and install meep from source. I'm still running the binary downloaded from the Debian web site. This is an older version and I don't think it includes the frequency solver, unless you are referming to MPB, then I know that requires a compile from source in order to install it.I generate the time solution with every run. It only adds the time needed to output the data files which is not much. My problem is converting the 4D data set then piecing it together. In particular the colors usually come out very weak and faded so there is not a lot to see. That is because the field strength near the antenna is high, while it is low in the areas of interest. This becomes a scaling problem for the color map. If I get a good set of images I will send them off to Tom Ligon who is good enough to convert them to a movie, then I will post the movie. But don't hold your breath.
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Quote from: SeeShells on 06/18/2015 06:47 pm...Considering these simple facts I've decided to make my Frustum(s) so that it will be able to change the internal dimensions to fine tune from my own best estimate and this is why I plan on building 3 different frustums and all will be adjustable. I stated designing the flexibility in my first one when I joined this group. ...That's a fantastic idea I'm working on a paper that shows what happens if you extend the cone into much smaller small diameters than what have been tried up to now. While extending the truncated cone into a cylinder is easy and has been done (using the cylinder to change the variable length) extending the cone, keeping the same cone angle , going to smaller and smaller bases and exploring what happens with Q, and the thrust, is one thing we need to explore.