See this article on a holey waveguide analysis with Meep:http://ab-initio.mit.edu/wiki/index.php/Meep_Tutorial/Band_diagram,_resonant_modes,_and_transmission_in_a_holey_waveguideIf anybody attempts to model the bases with holes in Meep, please note that this would involve a greater number of FD nodes that at present in the circular cross-section, and therefore the number of FD nodes in the circular cross section would end up being greater than in the longitudinal direction (unless those are also increased). If the FD cell defined by a number of FD nodes is too distorted (a long rectangle instead of an ideal square, or worse a geometrical figure with very different inscribed angles) numerical issues ensue, so please look into acceptable Finite Difference mesh distortion before meshing and calculating.

Wonder what would happen if I arrived at SpaceX reception, with several working 1N/kW EMDrive complete systems in tow and asked to see Elon Musk?

Quote from: TheTraveller on 07/15/2015 10:24 AMWonder what would happen if I arrived at SpaceX reception, with several working 1N/kW EMDrive complete systems in tow and asked to see Elon Musk? I would recommend the EMDrives towing you.

And no I'm not jumping the gun. It is all doable.

Quote from: TheTraveller on 07/15/2015 10:58 AMAnd no I'm not jumping the gun. It is all doable.I admire your confidence, but even as a hopeful and optimistic observer, you're really counting your chickens before they've hatched.

This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.

Quote from: TheTraveller on 07/15/2015 11:19 AMThis is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.Tangent question: Is there an off-the shelf source for a (preferably inexpensive) Sterling engine/generator combo? I saw a kickstarter for one a few years ago but that's it.I choose to ignore the high-quality perpetual motion machine bait.

Quote from: RotoSequence on 07/15/2015 11:05 AMQuote from: TheTraveller on 07/15/2015 10:58 AMAnd no I'm not jumping the gun. It is all doable.I admire your confidence, but even as a hopeful and optimistic observer, you're really counting your chickens before they've hatched. No not really. You see I have no doubt the EMDrive works as Shawyer claims. My plan just engages known knowledge plus engineer $s and hours to achieve a desired end result. I have committed $20k to the 1st and 2nd stages.1) Build EMDrive, CMS and rotary table to demo continual acceleration. SPR did this back in 2006 but their table could only turn a few revs due to cords. My table can turn an unlimited number of turns as it is cordless.2) Build and distribute 7 x 100W EMDrive complete systems to Force verifiers.Then commercial production of a 1kW Rf amp powered 1N/kW EMDrive becomes interesting. This system may be 2.45GHz or 5.8GHz or even 24GHz. Depends on test data.This is like building a conventional Sterling Engine and Generator combo but this Sterling Engine doesn't need any heat input to generate output energy to turn the Generator.

A 1kW RF amp that doesn't put any heat into the system... I wish! You could make a lot of money on just that alone if it were true.

Quote from: WarpTech on 07/15/2015 03:56 AMToddTodd,Any EMDrive theory must show the direction of the dielectric generated Force (Small to Big) at 180 deg opposite the non dielectric case (Big to Small) and the dielectric Force to be much weaker than the non dielectric case.Can your theory do that?

Todd

Momentum, spin, force, acceleration, mass, magnetic, electric forces of light, light is even a particle and a wave that exhibits quantum effects (slit experiment) and spooky actions of entanglement with superluminal instantaneous actions across long distances, evanescent waves like a stripped down version of a wave that can impart first order forces and control the movement of small particles. All of these forces and actions are carried in a wave. I keep remembering Einstein's equation E=MC2 and remind myself that light (energy) is simply a form of the forces that make matter what it is. If there is a formula for controlling mass and acceleration and warping spacetime like matter does it is in the waves (energy) on the other side of the equation. Making all this work like it does is the Quantum Vacuum of space-time.There are about 12 theories out there and each has pluses and minuses understanding how the fundamental makeup of light (RF shoved into in the EMDrive) can be modified to give us an effect that takes us places with out thrust. We really are not violating anything but using what mother nature gave us in E=MC2.So why is light massless?Einstein's special relativity says E2=p2c2+m2c4 and if E=pc, then we're all okay (? Ha) with zero mass... nonvanishing energy and momentum... my head spins.My hat is off to you here who can find the Betty Crocker ingredients in a photon to rip and cajole out mass and momentum.Shell Note to self. quit playing physics. Because some neutrinos are not massless. Another note: What Betty Crocker mix makes some neutrinos show mass and some not?

Quote from: SeeShells on 07/15/2015 02:44 PMMomentum, spin, force, acceleration, mass, magnetic, electric forces of light, light is even a particle and a wave that exhibits quantum effects (slit experiment) and spooky actions of entanglement with superluminal instantaneous actions across long distances, evanescent waves like a stripped down version of a wave that can impart first order forces and control the movement of small particles. All of these forces and actions are carried in a wave. I keep remembering Einstein's equation E=MC2 and remind myself that light (energy) is simply a form of the forces that make matter what it is. If there is a formula for controlling mass and acceleration and warping spacetime like matter does it is in the waves (energy) on the other side of the equation. Making all this work like it does is the Quantum Vacuum of space-time.There are about 12 theories out there and each has pluses and minuses understanding how the fundamental makeup of light (RF shoved into in the EMDrive) can be modified to give us an effect that takes us places with out thrust. We really are not violating anything but using what mother nature gave us in E=MC2.So why is light massless?Einstein's special relativity says E2=p2c2+m2c4 and if E=pc, then we're all okay (? Ha) with zero mass... nonvanishing energy and momentum... my head spins.My hat is off to you here who can find the Betty Crocker ingredients in a photon to rip and cajole out mass and momentum.Shell Note to self. quit playing physics. Because some neutrinos are not massless. Another note: What Betty Crocker mix makes some neutrinos show mass and some not?Before particles began to mix things up, photonic energy was considered ripples in space-time itself...simply a resonance of the fabric so to speak. A ripple on the ocean contains only the ocean; a massless force that created the ripple.So then came particles and the assumption of mass.

Quote from: TheTraveller on 07/15/2015 04:22 AMQuote from: WarpTech on 07/15/2015 03:56 AMToddTodd,Any EMDrive theory must show the direction of the dielectric generated Force (Small to Big) at 180 deg opposite the non dielectric case (Big to Small) and the dielectric Force to be much weaker than the non dielectric case.Can your theory do that?Traveller, is it true that a tapered waveguide with a dielectric insert in the small end will thrust towards the big end, and that the same tapered waveguide without the dielectric will thrust toward the small end? Do I have that right?With that in mind, how does Shawyer's variable group velocity ==> variable radiation pressure theory explain this flipping thrust direction?

Continued from here: http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404893#msg1404893Dissipation leads to decay of a wave form. Dispersion leads to gradual separation of wave patterns into a train of oscillations This depends upon constructive and destructive interference of Fourier components. Although many partial differential equations are nondispersive their Finite Difference approximations are almost invariably dispersive. Phase and group velocity analysis depend upon the problem being linear and nondissipative. Thus this problem (EM Drive truncated cone with RF feed ON) is not as trivial as R. Shawyer makes it to be nor as its detractors make it to be. The whole discussion about "phase vs. group velocity" is too simplistic for a truncated cone with the RF feed ON. In a numerical scheme like Finite Differences (used by Meep) group velocity has more physical meaning than phase velocity. On a periodic grid any Fourier mode can be represented in terms of infinitely many possible choices of frequency and wavevector that are indistinguishable physically. Each choice gives a different phase velocity.One cannot tell how fast a pure complex exponential wave is moving if one sees it at only intermittent points in space or time for one wave crest is indistinguishable from another. By contrast the group velocity is well defined since it depends only on the slope which is a local property formula.But if the problem entails dissipation as well dispersion, the discussion about phase vs. group velocity (and what they mean) approaches being moot, since such confining discussion would ignore the dissipation aspect of the problem.