Perhaps a poll would be in order?
Quote from: Hauerg on 07/22/2015 08:06 pmACDAsymmetric Cavity DriveThis debate is actually not really helpful. The one who explains the correct physics will give it a name in his paper, or do it democratically, but let's go back to science right now This for example: ghost modes in imperfect waveguideshttp://bayes.wustl.edu/etj/articles/ghost.modes.pdf
ACDAsymmetric Cavity Drive
DIYer head's up. Copper flashing seems to be a cost-effect solution for frustum walls if you are not using mesh. As I was looking around for supplies, found this: http://www.acehardware.com/product/index.jsp?productId=1290779&KPID=984489&kpid=984489&pla=pla_984489A 10ft roll seems to be the smallest length. I'd recommend the 14 inch for frustum heights to 11 inches. I can say from experience that .021 thickness will not be self-supporting and an exoskeleton will be needed. When I switched to a magnetron, the 1/8 in square copper supports were not ideal. I'd move to 1/4 in copper struts or possibly tubing.Top and bottom plates on nsf-1701 were 1/2 oz copper clad pc board, again too flimsy for a 750g magnetron. Try the next size up. Solid copper plates would weigh too much, I stick with the pcb stuff, just make sure there are plated thru-holes or plenty of bolts to connect the 2 ground planes.Any metal above ground potential will be subject to plasma discharge, so "mind the gaps" p.s. Bonus points for anyone who knows that phrase...
The Space Show will have Dr. Jim Woodward on tonight. Tuesday, July 21, 2015; 7-8:30 PM PDT (10-11:30 PM EDT; 9-10:30 PM-1 PM CDT): We welcome DR. JJIM WOODWARD back to the show to update us on his work with a Mach effect drive impulse engine- and gravitational physics. http://www.thespaceshow.com/
Cut-off is a concept that applies to constant section waveguides. It does not apply to tapered waveguides, as it has been remarked and shown in several peer-reviewed papers I have pointed out ... In a tapered waveguide modes do not get cut-off, instead the modes persist, with a larger diameter region where the wave is a traveling wave to a transition region to a region near the apex where the wave becomes evanescent.
@SeeShell - Your .png and .csv files data is/are up have been uploaded here:https://drive.google.com/folderview?id=0B1XizxEfB23tfm04QWNVVVVvT3gtcVAzRUp6T1BCLVpoV0EyeVVKR2ZxQkp2a3NKcUNPMU0&usp=sharingI uploaded my meep data request file/form to hopefully explain what the data is, although it needs more English and fewer Scheme statements. The inside big end is at row 15 and small end at row 216 of the csv files, and the total run meep time t = 13.054 (6527 timesteps).
{snip}Any metal above ground potential will be subject to plasma discharge, so "mind the gaps" p.s. Bonus points for anyone who knows that phrase...
Quote from: rfmwguy on 07/22/2015 08:11 pmDIYer head's up. Copper flashing seems to be a cost-effect solution for frustum walls if you are not using mesh. As I was looking around for supplies, found this: http://www.acehardware.com/product/index.jsp?productId=1290779&KPID=984489&kpid=984489&pla=pla_984489A 10ft roll seems to be the smallest length. I'd recommend the 14 inch for frustum heights to 11 inches. I can say from experience that .021 thickness will not be self-supporting and an exoskeleton will be needed. When I switched to a magnetron, the 1/8 in square copper supports were not ideal. I'd move to 1/4 in copper struts or possibly tubing.Top and bottom plates on nsf-1701 were 1/2 oz copper clad pc board, again too flimsy for a 750g magnetron. Try the next size up. Solid copper plates would weigh too much, I stick with the pcb stuff, just make sure there are plated thru-holes or plenty of bolts to connect the 2 ground planes.Any metal above ground potential will be subject to plasma discharge, so "mind the gaps" p.s. Bonus points for anyone who knows that phrase...Had to do with electric trolleys I think. Before my time.One thing you need to be aware of in copper is that it's mixed with tin to prevent corrosion, 80-90% mix is normal and if not 99% pure copper it will cause more heating signal loss and not be as a good cavity.ShellPS:I'm still waiting (have some time) for my last piece of copper is holed out to my specs, was hoping to have a simulation run, it is 99% pure the same they use in waveguides.
Quote from: rfmwguy on 07/22/2015 08:11 pm{snip}Any metal above ground potential will be subject to plasma discharge, so "mind the gaps" p.s. Bonus points for anyone who knows that phrase...Seems appropriate for an underground transport system.
Quote from: aero on 07/22/2015 07:08 am@SeeShell - Your .png and .csv files data is/are up have been uploaded here:https://drive.google.com/folderview?id=0B1XizxEfB23tfm04QWNVVVVvT3gtcVAzRUp6T1BCLVpoV0EyeVVKR2ZxQkp2a3NKcUNPMU0&usp=sharingI uploaded my meep data request file/form to hopefully explain what the data is, although it needs more English and fewer Scheme statements. The inside big end is at row 15 and small end at row 216 of the csv files, and the total run meep time t = 13.054 (6527 timesteps).I see a number of files labeled as follows: AxialAnt-##-eXBc.csv and AxialAnt-##-eXSc.csv where I suppose ## stands for the time slice number, X stands for components x, y and z, and "B" stands for BigBase and "S" stands for SmallBase.However, these are all Electric Field components. I don't see any files labeled AxialAnt-##-hXBc.csv or AxialAnt-##-hXSc.csv with the Magnetizing H field components. To calculate the stresses I need all 6 components: all E components and all H components.Are the Magnetizing H field component files for the AxialAnt case somewhere and I missed them ?
Quote from: VAXHeadroom on 07/21/2015 08:15 pmThe Space Show will have Dr. Jim Woodward on tonight. Tuesday, July 21, 2015; 7-8:30 PM PDT (10-11:30 PM EDT; 9-10:30 PM-1 PM CDT): We welcome DR. JJIM WOODWARD back to the show to update us on his work with a Mach effect drive impulse engine- and gravitational physics. http://www.thespaceshow.com/The show has archived: http://thespaceshow.com/detail.asp?q=2509Direct link to audio: http://archived.thespaceshow.com/shows/2509-BWB-2015-07-21.mp3Both Sonny White and Paul March were mentioned in passing, but EM Drive was not specifically discussed.~Kirk
...I wondered why that went quicker last night. Not quick but a little quicker. I guess you found out. Check it again, they are there now.
To all those proposing to use Thruster in the name, I reiterate what rfmwguy said:Quote from: rfmwguy on 07/22/2015 06:10 pmElectromagnetic Drive or Reactor seems safe, perhaps a little better than Thruster since we're not 100% sure its pushing rather than pulling.
Electromagnetic Drive or Reactor seems safe, perhaps a little better than Thruster since we're not 100% sure its pushing rather than pulling.
Quote from: aero on 07/22/2015 11:50 pm...I wondered why that went quicker last night. Not quick but a little quicker. I guess you found out. Check it again, they are there now.I'm looking at the Yang/Shell Axial Antenna at Big Base case now: very unusual: the stress, and hence the force at the small base is practically zero. The stress at the big base is a central point stress from the antenna. Close inspection of this mode looks like another TM11 transverse magnetic mode but with drastically different amplitude.QUESTION1: was the mesh kept the same as in the previous csv Yang/Shell case, and you are sure this is the stress at the small base and not outside it?Most important: QUESTION2: did Meep give you a Q value for this case ?Thanks
Quote from: leomillert on 07/22/2015 08:00 pmTo all those proposing to use Thruster in the name, I reiterate what rfmwguy said:Quote from: rfmwguy on 07/22/2015 06:10 pmElectromagnetic Drive or Reactor seems safe, perhaps a little better than Thruster since we're not 100% sure its pushing rather than pulling.What could the possible difference be between "pushing" and "pulling"?