Quote from: aero on 06/30/2015 07:35 PM@Dr. RodalWould you like for me to change my coordinate system to make the z axis the axis of rotation? I could do that, most likely it would be quick, but I won't re-run the data that I have already uploaded so you would need to remember which runs are calculated with "image" coordinates and which runs are calculated with "physics conventions."No thanks. It is just that it was not clear to me what plane we were looking at. Now I understand that we are looking at the y-z plane. Thanks.Everything is OK at this point. Don't need a 12 GB file at this point .What I would is to get a trapezium view (instead of a circular view) numerical data for L=10.2 for one of the electric view that clearly showed 4 or 3 waves. It is very difficult to see visualize a circle as a square. It will be easier looking at a trapezium view.

@Dr. RodalWould you like for me to change my coordinate system to make the z axis the axis of rotation? I could do that, most likely it would be quick, but I won't re-run the data that I have already uploaded so you would need to remember which runs are calculated with "image" coordinates and which runs are calculated with "physics conventions."

Quote from: Rodal on 06/29/2015 07:40 PMQuote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=45) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE mode6) How can that be? An examination of the eigenvalue problem using Mathematica and the exact solution shows:TE114 = 2.434 GHzTM114 = 2.479 GHzCONCLUSION: TE114 is excited with strong participation of TM114 We see the strength of Meep: while all the other analysis (including COMSOL FEA by NASA) have been eigenvalue analyses, the Meep solution is a transient solution in time, hence it automatically incorporates a spectrum analysis: it looks at participation of nearby modes. (This can also be done with COMSOL FEA and other FEA programs of course, but nobody else has reported transient solutions up to now).Having two modes with equal m, n, p, nearby results in participation of both modes (having 114 mode shape).I was thinking that because the intensity scale is fixed over each complete view data set, and there is little or no increase in intensity from beginning to end of the run, then the cavity is not resonating very well, certainly not strongly. The fractal nature of the H fields support that thought, by indicating low energy. JMO. Perhaps I will make the same run using a Gaussian source. Noise Bandwidth say, What? What is the noise bandwidth of a magnatron?

Quote from: aero on 06/29/2015 06:22 PMViews of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.Since we continue without having any numerical result, we have to resort to some heuristic as following to interpret these pictures:1) Picture showing fractal are a numerical artifact due to values close to zero, hence pictures with fractals should be interpreted as low values close to zero2) Concentrate on images showing smooth and persistent contours (persistent in several frames)3) Use the field in the longitudinal x direction to determine mode shape4) Conduct independent eigenvalue analysis to determine frequencies of several modes at 10.2 inches.///////////////////Using the above-mentioned heuristics, we determine:1) The strong field in the longitudinal x direction is Ex, in this case Ex -y (the electric field in the longitudinal direction, seen in the x-z plane with normal y). This field shows 4 wave patterns in the longitudinal direction. Hence p=4. Notice that Ex - z is zero.2) Hx -y and Hx -z are fractal hence interpreted as close to zero3) Actually all magnetic fields in this case appear to be fractal, hence interpreted as very low, close to zero4) Ez is strong both in the planes with y and z normals. Both show p=45) The strong Ex points towards a TM mode. The lack of any strong H field in the transverse direcitons points towards a TE mode6) How can that be? An examination of the eigenvalue problem using Mathematica and the exact solution shows:TE114 = 2.434 GHzTM114 = 2.479 GHzCONCLUSION: TE114 is excited with strong participation of TM114 We see the strength of Meep: while all the other analysis (including COMSOL FEA by NASA) have been eigenvalue analyses, the Meep solution is a transient solution in time, hence it automatically incorporates a spectrum analysis: it looks at participation of nearby modes. (This can also be done with COMSOL FEA and other FEA programs of course, but nobody else has reported transient solutions up to now).Having two modes with equal m, n, p, nearby results in participation of both modes (having 114 mode shape).

Views of NSF-1701 are up:https://drive.google.com/folderview?id=0B1XizxEfB23tfklENXg2TWhrbUhneGxZQzJ0VVhkRFRwUUhCN2xKX24yOGM2bFQzdVV5NlE&usp=sharingThis file shows the 18 views of the E and H components from x, y and z directions.This is from a Meep model of rfmwguy's 10.2 inch cavity, in copper, driven by a 2.45000 GHz continuous Ez source. The resonant frequency of this cavity is somewhere close to 2.45 GHz but no resonance solutions indicate exactly 2.45 GHz. The continuous source used in this model is ideal and exact. There are no "shoulders" on the input power source, all input energy is at exactly the drive frequency, 2.45 GHz. The antenna model, a dipole, is oriented perpendicular to the central axis of rotation, one-half wavelength from the small end, and is 0.058 meters long.An important point is to note that these views use a fixed Max/Min range of power/color intensity. I'll leave it to the experts to analyse the characteristics shown.

It is well-known, since the seminal works by J.H. Poynting [1], that light carriesmomentum and angular momentum (AM) [2,3]. Typical plane-wave or Gaussian-beamstates exhibit longitudinal momentum associated with the wave vector k and alsolongitudinal spin AM associated with the degree of circular polarization (helicity) σ .Locally, optical momentum and angular-momentum densities can demonstrate unusualfeatures which have recently attracted considerable attention: “super-momentum” withvalues higher than (hbar)k per photon [4–8], transverse helicity-independent spin AM [9–12],and transverse helicity-dependent momentum [10,13,14]. So far, such abnormalmomentum and spin properties have appeared only in special field configurations, namely,evanescent waves and optical vortices. Here we find that the simplest propagating nonsingular field – two interfering plane waves – also exhibits a variety of extraordinary spinand momentum properties. Despite the seemingly planar and thoroughly-studied characterof the two-wave system, we discover that such field possesses a transverse (out-of-plane)helicity-independent spin AM, and also a transverse polarization-dependent momentumwith unusual physical properties.

Quote from: Rodal on 06/30/2015 07:42 PMQuote from: aero on 06/30/2015 07:35 PM@Dr. RodalWould you like for me to change my coordinate system to make the z axis the axis of rotation? I could do that, most likely it would be quick, but I won't re-run the data that I have already uploaded so you would need to remember which runs are calculated with "image" coordinates and which runs are calculated with "physics conventions."No thanks. It is just that it was not clear to me what plane we were looking at. Now I understand that we are looking at the y-z plane. Thanks.Everything is OK at this point. Don't need a 12 GB file at this point .What I would is to get a trapezium view (instead of a circular view) numerical data for L=10.2 for one of the electric view that clearly showed 4 or 3 waves. It is very difficult to see visualize a circle as a square. It will be easier looking at a trapezium view.The circle is not a square. The circle is embedded within the square. The radius of the circle is 11.01 inches = BIG DIAMETER = 0.29235399999999995 meters and compare with the dimensions of the square computational lattice, 0.3168268537142857 x 0.3168268537142857 meters. The circle is surrounded by the cone skin, thickness = 1/4 inch or 6.35 mm. Maybe you can find that in the data?

Quote from: X_RaY on 06/30/2015 08:35 PM....I can not belive this modes, i get TE013, TE114, TM113 near 2,45 GHz (analytical).TM114 is located at a much higher frequency (~2.9GHz) I cant't believe your numbers. What code are you using to get such a high frequency Have you ever checked your code against other solutions for a truncated cone?COMSOL's FEA analysis gives TM212 for L=9 inches at 2.45 GHz and TM114 at a much lower frequency. Are you using the formula for a cylinder? or some numerical approximation that is way too stiff?Sounds like something is wrong with your calculation for TM114

....I can not belive this modes, i get TE013, TE114, TM113 near 2,45 GHz (analytical).TM114 is located at a much higher frequency (~2.9GHz)

I was thinking about the "Thrust greater than a photon rocket" quandry, and came across something interesting.Source Paper: Transverse Spin and Momentum in Two-WaveInterference http://www.researchgate.net/publication/264276617QuoteIt is well-known, since the seminal works by J.H. Poynting [1], that light carriesmomentum and angular momentum (AM) [2,3]. Typical plane-wave or Gaussian-beamstates exhibit longitudinal momentum associated with the wave vector k and alsolongitudinal spin AM associated with the degree of circular polarization (helicity) σ .Locally, optical momentum and angular-momentum densities can demonstrate unusualfeatures which have recently attracted considerable attention: “super-momentum” withvalues higher than (hbar)k per photon [4–8], transverse helicity-independent spin AM [9–12],and transverse helicity-dependent momentum [10,13,14]. So far, such abnormalmomentum and spin properties have appeared only in special field configurations, namely,evanescent waves and optical vortices. Here we find that the simplest propagating nonsingular field – two interfering plane waves – also exhibits a variety of extraordinary spinand momentum properties. Despite the seemingly planar and thoroughly-studied characterof the two-wave system, we discover that such field possesses a transverse (out-of-plane)helicity-independent spin AM, and also a transverse polarization-dependent momentumwith unusual physical properties.I only speak pidgin math, but I think the paper translates to say "We predict radiation pressure effects greater than hk/c perpendicular to the plane of incidence when two polarized waves cancel out".Could I impose on someone to verify my translation?

Quote from: Rodal on 06/30/2015 08:47 PMQuote from: X_RaY on 06/30/2015 08:35 PM....I can not belive this modes, i get TE013, TE114, TM113 near 2,45 GHz (analytical).TM114 is located at a much higher frequency (~2.9GHz) I cant't believe your numbers. What code are you using to get such a high frequency Have you ever checked your code against other solutions for a truncated cone?COMSOL's FEA analysis gives TM212 for L=9 inches at 2.45 GHz and TM114 at a much lower frequency. Are you using the formula for a cylinder? or some numerical approximation that is way too stiff?Sounds like something is wrong with your calculation for TM114I used the L=10.2inch=259,08 mm; Big Diameter=259,08 mm; Small Diameter =148...155mm .I integrate over several frequencies given by a fixed length and the Diameter an any z position on this axis to get the eigenvalue of the mode (with respect to the given bessel-funktion of each mode)This works good enough. I work daily with this code to build conical cavities for NDT-Solutions (I calculate and build the cavities). The frequencies fits for the Eigenstates. (antenna and losses/London penetration depth gives a small frequency shift...). Got a good equipment available (Spec, VNA...!)TE013 2,540899898GHzTE114 2,4817950934GHzTM113 2,5445470879GHz

Quote from: X_RaY on 06/30/2015 09:04 PMQuote from: Rodal on 06/30/2015 08:47 PMQuote from: X_RaY on 06/30/2015 08:35 PM....I can not belive this modes, i get TE013, TE114, TM113 near 2,45 GHz (analytical).TM114 is located at a much higher frequency (~2.9GHz) I cant't believe your numbers. What code are you using to get such a high frequency Have you ever checked your code against other solutions for a truncated cone?COMSOL's FEA analysis gives TM212 for L=9 inches at 2.45 GHz and TM114 at a much lower frequency. Are you using the formula for a cylinder? or some numerical approximation that is way too stiff?Sounds like something is wrong with your calculation for TM114I used the L=10.2inch=259,08 mm; Big Diameter=259,08 mm; Small Diameter =148...155mm .I integrate over several frequencies given by a fixed length and the Diameter an any z position on this axis to get the eigenvalue of the mode (with respect to the given bessel-funktion of each mode)This works good enough. I work daily with this code to build conical cavities for NDT-Solutions (I calculate and build the cavities). The frequencies fits for the Eigenstates. (antenna and losses/London penetration depth gives a small frequency shift...). Got a good equipment available (Spec, VNA...!)TE013 2,540899898GHzTE114 2,4817950934GHzTM113 2,5445470879GHzSorry, it looks like your solution does not work good enough (at least for this case):You calculate TM113 2,5445470879GHz for L=10.2 inches, which shows that something is very wrong with your calculation.NASA COMSOL FEA calculates for L = 9 inches that TM113 has a lower frequency: TM113 at 2.273 GHz for L=9 inchesthe exact solution gives TM113 2.24832 GHz for L = 9 inches (good agreement with NASA COMSOL FEA)Frequency goes down with length, not up !!! So for L=10.2 the frequency of TM113 is even lower !!!instead of higher as you calculate (2.545 GHz for L=10.2 inches)NOTE: I notice that you are using cylindrical Bessel functions. The correct functions for truncated cone are the Associated Legendre function and the Spherical Bessel Functions.

...OK maybe (like i said that are analytical things! Maybe i have to increase the Points along the z-axis?)Did i used the right Diameter data?

I used the L=10.2inch=259,08 mm; Big Diameter=259,08 mm; Small Diameter =148...155mm ....OK maybe (like i said that are analytical things! Maybe i have to increase the Points along the z-axis? I use 15 at the moment this could be a little bit less for modes with higher p value )Did i used the right Diameter data?

Quote from: X_RaY on 06/30/2015 09:23 PMI used the L=10.2inch=259,08 mm; Big Diameter=259,08 mm; Small Diameter =148...155mm ....OK maybe (like i said that are analytical things! Maybe i have to increase the Points along the z-axis? I use 15 at the moment this could be a little bit less for modes with higher p value )Did i used the right Diameter data?It looks like your diameters are wrong:NASA FrustumHeight: 9.00 inch (228.6 mm)Top diam.: 6.25 inch (0.1588 mm) Bottom diam.: 11.01 inch (279.7 mm)Material: 101 Copper Alloy

.... The em-drive will eventually take its place next to cold fusion, polywater, and 300 MPH submarines in the Encyclopedia of Pseudoscience.

Quote from: Fractal on 06/30/2015 04:37 PMQuote from: rfmwguy on 06/30/2015 12:40 AMWeird, take a look at: http://jnaudin.free.fr/lifters/act/html/omptv1.htm"On January 31, 2002, the NASA patent application US2002012221 " Apparatus and Method for generating a thrust using a two dimensional asymmetrical capacitor module " has been granted."Looks alot like a shawyer frustum...From the article:The dielectric material of a capacitor under high voltage experiences a force. Based on the geometry of the capacitor, its material properties, and ambient conditions, the force can be predicted and utilized to move the entire capacitor and its mounting in a predictable direction.Are there any parts of the EM drive that may act as a high voltage capacitor?More like a high current inductor.

Quote from: rfmwguy on 06/30/2015 12:40 AMWeird, take a look at: http://jnaudin.free.fr/lifters/act/html/omptv1.htm"On January 31, 2002, the NASA patent application US2002012221 " Apparatus and Method for generating a thrust using a two dimensional asymmetrical capacitor module " has been granted."Looks alot like a shawyer frustum...From the article:The dielectric material of a capacitor under high voltage experiences a force. Based on the geometry of the capacitor, its material properties, and ambient conditions, the force can be predicted and utilized to move the entire capacitor and its mounting in a predictable direction.Are there any parts of the EM drive that may act as a high voltage capacitor?

Weird, take a look at: http://jnaudin.free.fr/lifters/act/html/omptv1.htm"On January 31, 2002, the NASA patent application US2002012221 " Apparatus and Method for generating a thrust using a two dimensional asymmetrical capacitor module " has been granted."Looks alot like a shawyer frustum...

Hey, quick question to those savvy with microwaves:We would like to determine how well the magnetron is matched with the manufacturers microwave box so that we have a baseline for safe operating impedance of the magnetron. My idea is to put several temperature probes on the magnetron outside core and heat sink fins and log data. Our probes max out at 130 C, does anyone have any idea how quickly an uncooled magnetron will get there?This method would allow a simple impedance measurement so that any subsequent cavity we create can be compared to the original microwave. [I'd be making the assumption that the manufacturer created a cavity that is well matched to the magnetron to minimize reflected power. Is this a valid assumption? ] Any thoughts, concerns, suggestions? Kurt

Quote from: Silvercrys3467 on 06/29/2015 10:57 PMBeen following this thread for a few weeks, decided to hop in to help if I could.Aero, do you need only the most recent MEEP package?I was going to go ahead and compile it from source for you but I found:http://ab-initio.mit.edu/wiki/index.php/Meep_DownloadAccording to the wiki, they have a precompiled source package available:"apt-get install meep h5utils"There is also a parallel source file:"apt-get install meep-mpi"If you need other packages compiled with it or the OpenMPI version, I will see what I can do.I saw that one as well and was going to try it out. If you want to help, you could try to create a Ubuntu package for Meep as aero uses Ubuntu (and so am I and a few others). http://packaging.ubuntu.com/html/I also do not know which compiler / optimization the source code would support, but you may want to explore recompiling the source using different compilers (gcc / LLVM / ICC / VC ...) and different optimization flags. It can also be that the source code could enjoy being made more compiler agnostic.

Been following this thread for a few weeks, decided to hop in to help if I could.Aero, do you need only the most recent MEEP package?I was going to go ahead and compile it from source for you but I found:http://ab-initio.mit.edu/wiki/index.php/Meep_DownloadAccording to the wiki, they have a precompiled source package available:"apt-get install meep h5utils"There is also a parallel source file:"apt-get install meep-mpi"If you need other packages compiled with it or the OpenMPI version, I will see what I can do.

...I suggest that you may wish to look at some of the fields generated with the Gaussian source as they appear to be much stronger than those calculated using the continuous source. Csv files are available for the big end base view, and I'll see about creating csv files for the "transverse" view.Regarding your observation, "observe that there are no field values outside the circle" I disagree. If there were no fields, the background would show as black, I think. There is some energy there, just the fields are so weak compared to the fields inside that they are not differentiated by color from some very small value.