-
#1840 by rfmwguy on 17 Jan, 2016 16:22
-
Rfplumbers em weapon
- add another grounded fr4 board to small end, metal tape, whatever...to increase cavity reflectivity. Repeat as needed. Measuring FS in all orientations is an excellent idea.
Edit - another thought...aluminum tape uses non conductive adhesive. Might try old fashioned solder wick around cleaned seam...tape in place. -
#1841 by zen-in on 17 Jan, 2016 16:25
-
Major RF Leak
I will appreciate any advice and hints.
...
Came to about 20 dB, ok, about 1W leaking, no big deal, let us cover all the gaps with adhesive copper foil and be done with it. Re-measured Q – it didn’t change, doesn’t matter… re-measured leak… it didn’t appear to change either… umm… I thought my little WiFi antennas may not be showing the real picture
...
Which makes me believe that replacing all that adhesive copper with a better solution will not change much.
How is this possible?? I am not even sure what to try next about it... Solder the small end to the main body for good? Replace the small end with copper sheet instead of FR4? Neither of these should even be related…
The only time I have used adhesive Copper to fix an RF problem we burned the adhesive off and soldered it in. The adhesive is an insulator to RF. When you apply adhesive Copper to something you are just making a big capacitor. Do you remember those no-drill cell antennas they used to put on cars? That's the same idea. A capacitor couples the RF to the exterior antenna. You should remove the adhesive from that stuff and solder it in place. There is an advantage to soldering sheets of Copper over the gaps vs filling the gaps in with lead solder, or even worse conductive epoxy. To make the fustrum RF-tight there have to be Copper surfaces everywhere and no glue. -
#1842 by rfmwguy on 17 Jan, 2016 16:35
-
Beat me to it zen...
-
#1843 by birchoff on 17 Jan, 2016 16:43
-
NASA's experiments conclusively showed NO thrust with TE012 without a dielectric insert: see https://forum.nasaspaceflight.com/index.php?topic=39214.msg1469685#msg1469685I have kind of a general question:
quote
Since now it is proven, that the dielectric insert is needed to get thrust it seems that Woodward effect and not
Alcubierre space-time warping is what constitutes the physical background of the thrust.
Am I right to conclude, that any spaceship with an EMthruster would be subject to
time dilatation and relativistic mass increase?
E.g. meaning that, while a trip to a different solar system with such a ship, given an EMThruster that can accelerate to some 0.999.. c in an acceptable short time, could take a couple of weeks in the ship coordinate system, it could take years in earth and target planet coordinate systems.
"Since now it is proven, that the dielectric insert is needed to get thrust it seems that Woodward effect and not
Alcubierre space-time warping is what constitutes the physical background of the thrust."
I don't think it has been proven that a dielectric insert is needed but. if one is used running TE012 mode where the energy of the E-fields is focused in the small ends of the frustum would be highly desirable.
On another site someone took my frustum dimensions with dual waveguides and simulated one cycle of 2.45 GHz into the cavity. What is interesting is meep and FEKO agree on the modes but where meep visualizes internals FEKO visualized the cavity walls.
So if a dielectric insert was a way to seed and amplify the effect it seems that a TE012 or another mode exciting the small end is the way to go.
Shell
https://drive.google.com/file/d/0B6juR48k_XoTc1Eya01XeG1SME0/view
This NASA test is very important because it was conducted with exactly the same mode shape claimed by Prof. Yang for her experiments claiming the largest force/PowerInput ever claimed for an EM Drive ( http://emdrive.wiki/Experimental_Results ). And Roger Shawyer has apparently used TE012 and TE013 mode shapes for his Demonstrator and Flight Thruster. So this NASA test is very relevant.
TheTraveller claims that the reason is that NASA's EM Drive small end was slightly below the cut-off condition for open waveguides. Since the EM Drive is a closed resonant cavity and we learned at school that such condition does not apply to closed resonant cavities, and since Shawyer has never published any experiments whatsoever supporting his strange claim for the cut-off condition, this explanation is not convincing. Furthermore, independent calculations show that the NASA test without dielectric should have had strong theoretical Q (79,000), that the cut-off condition is completely irrelevant for resonance of a closed cavity and even more important, the experimental evidence from NASA shows strong confirmation that the NASA test without dielectric was in resonance.
There is no reported test ever by NASA showing thrust for an EM Drive without a dielectric insert.
____________________
...
While I agree that EW was able to pull off an experiment of a Frustum with no dielectric and recorded no anomalous force. I am not ready to accept that a dielectric is absolutely needed to generate the anomalous force. As I understand it all the DIY experiments being done here will not be using dielectrics so assuming their experimental setup will be accurately recorded I will wait until those results are disclosed before closing the door on this matter. -
#1844 by Rodal on 17 Jan, 2016 16:50
-
...
The show
While I agree that EW was able to pull off an experiment of a Frustum with no dielectric and recorded no anomalous force. I am not ready to accept that a dielectric is absolutely needed to generate the anomalous force. As I understand it all the DIY experiments being done here will not be using dielectrics so assuming their experimental setup will be accurately recorded I will wait until those results are disclosed before closing the door on this matter.QuoteIt ain't over till the fat lady sings
https://en.wikipedia.org/wiki/It_ain%27t_over_till_the_fat_lady_sings
-
#1845 by birchoff on 17 Jan, 2016 17:03
-
That Woodward's and White's formulations respect Relativity, including time dilation, does not, by itself, preclude the Alcubierre metric "warp drive". Rather, the Alcubierre "warp drive" problem is the need for "negative mass/energy", something that is not available (and hence considered by many physicists as a non-starter), and it has other important dificulties: https://en.wikipedia.org/wiki/Alcubierre_drive#Difficulties . The creator of the Alcubierre concept, Alcubierre himself is on record saying that the "Alcubierre drive" is not something that can be done:I have kind of a general question:
Yes[...]
Since [...]
That is unfortunate... I had the hope that we could see a realization of Alcubierre metric within the EMThruster.
But well, it is no use complaining. It is like it is.
This will mean that there is and will be a limit of travelling distance. Although not a technical but a social one.
Since very long travel would mean you could get to other solar systems in weeks but thousands of years would have past when you come back to earth. So you will leave everyone and everything behind.Quote from: Alcubierre"from my understanding there is no way it can be done, probably not for centuries if at all" https://twitter.com/malcubierre/status/362011821277839360
. On the other hand, concerning Dr. White's views on this, Dr. White seems to say that it is possible, pay particular attention to this question from a NASA Ames scientist:
"A question with no answer" (acknowledgment to NSF user "StrongGR", Dr. Marco Frasca)
Wikipedia (https://en.wikipedia.org/wiki/Alcubierre_drive#Experiments) states: <<In 2013, the Jet Propulsion Laboratory published results of a 19.6-second warp field from early Alcubierre-drive tests under vacuum conditions>> but it shows no reference to support this statement. The only such experiments I'm aware of are the ones by Dr. White's group at NASA Johnson Eagleworks Lab instead of at JPL (https://en.wikipedia.org/wiki/White%E2%80%93Juday_warp-field_interferometer#Results).
So I think most people come at the EmDrive and Woodwards MET as being valuable because they would drastically reduce the cost of colonizing space. While that is one side effect of either or both being true. From where I stand the real value is that they will yield a new way to observe and interact with spacetime/quantum vaccum.
If the EmDrive/MET is shown to be consistent with either Dr.White's/Woodward's theory both men are of the belief that it may be possible to open up exploration of the galaxy. From Dr. White's perspective it is leveraging his understanding of EmDrive (which he believes is a QThruster) to create a Warp Drive. And for Woodward, assuming his proposal about the electron's true mass is accurate then you would be able to create worm hole generators.
So the time dilation limitation of either of these, what I would call first generation, devices is not anything to worry about. If they do work, they will serve us well in many ways. However, if they do work they continue to leave the door open for the more interesting conclusions of Dr. White's/Woodwards theories. -
#1846 by SeeShells on 17 Jan, 2016 17:04
-
The FEKO simulation (https://drive.google.com/file/d/0B6juR48k_XoTOUZjTTdTeW14X0U/view) of Shell's experiment, with a 180 degree phase shift, shows a TM21p mode shape instead of TM11p with 0 degree phase shift. This higher order (quadrupole) transverse magnetic mode shape is similar (on the circular cross-section) as NASA's mode shape used for their experiments in vacuum (TM212 for NASA).
Yes, many questions indeed.
This mode shape is also inconsistent with the expectation of a TE013 mode shape.
The poles for this TM21p mode FEKO simulation are not equal in size (they should be completely equal in size for a well-formed axisymmetric TM21p mode shape). This maybe due to the asymmetry imposed by the dual waveguides: observe that the poles that align with the waveguides axis are smaller in size that the poles that are perpendicular to the waveguides axis.
The FEKO mode shape for this 180 degree phase shift on the lateral conical walls is not axisymmetric. This appears to be a consequence of the asymmetry imposed by the lateral waveguides that distort what would have otherwise been an axisymmetric mode shape.
_______
Can't comment more than that as I did not find out more information about what particular FEKO module simulation was used (is the FEKO Finite Difference in time and space being used? or is it the FEKO Boundary Element Method (which the author calls Method of Moments) ?, or is the FEKO Finite Element simulation being used. Many questions ...
Here is a run with the dual waveguide Cu drude model of the E components in December. tell me what you see.
One thing is apparent with the dual waveguides (hopefully with the direct waveguide design the phases as well), plus the tune chamber, is I can control and generate multiple modes and how they form and propagate or not.
https://drive.google.com/folderview?id=0ByMNWRlWDxlxYXRRV2JjWE1Pb1U&usp=sharing
Shell
Added
Also if you look at the arrows into the waveguides you'll see the RF insertion was not the same as my model. They used the endplate of the waveguide instead of the side wall. This will want to produce a TM mode.
-
#1847 by RERT on 17 Jan, 2016 17:32
-
Dr. Rodal, RFPlumber -
Many thanks for posting the COMSOL data for the 100W frustrum. I'm only phone in a cafe now, and will do more justice to reviewing it when I get to my desk tomorrow.
FWIW, I'm counting 498 A/m versus my SWAG of 1900 (for some random frustrum!) as at least a score-draw. Also interesting to note that the 498 might be nearer 1000 if anyone managed to get half of the 800w of magnetron power into a frustrum.
Why is the number interesting? Well, two papers, Furza and Tuval's have pointed to arrangements if current loops as having potentially significant effects.
The first says that current loops can produce (barely) detectable gravitational effects.
The second points out that current loops with varying current can produce a non-zero net force on the total system. In any case, the Lorentz forces on internal current loops are relevant to the matter at hand.
Obviously, the two are unrelated, and not likely in themselves to explain any EMDrive effect.
However, between them, they are more than sufficient to motivate me to want to know the rough size of the currents we are creating in the frustrum walls.
I hope that helps, I've probably been brief enough earlier to make my interest seem entirely random.
Thanks again,
R. -
#1848 by TheUberOverLord on 17 Jan, 2016 18:12
-
Was there some kind of recent change made less than an hour ago. I ask because I was not allowed to see page 93 until I formally logged in which was not required 45 minutes or so ago. The error was "Only registered members are allowed to view this area, please login".
IMHO, if this was not some fluke. Would this not be a bad idea to do since it was not required to be a member or formally login to gain access to these Forum threads in the past? For viewing purposes.
Don
-
#1849 by Rodal on 17 Jan, 2016 18:25
-
I see:The FEKO simulation (https://drive.google.com/file/d/0B6juR48k_XoTOUZjTTdTeW14X0U/view) of Shell's experiment, with a 180 degree phase shift, shows a TM21p mode shape instead of TM11p with 0 degree phase shift. This higher order (quadrupole) transverse magnetic mode shape is similar (on the circular cross-section) as NASA's mode shape used for their experiments in vacuum (TM212 for NASA).
Yes, many questions indeed.
This mode shape is also inconsistent with the expectation of a TE013 mode shape.
The poles for this TM21p mode FEKO simulation are not equal in size (they should be completely equal in size for a well-formed axisymmetric TM21p mode shape). This maybe due to the asymmetry imposed by the dual waveguides: observe that the poles that align with the waveguides axis are smaller in size that the poles that are perpendicular to the waveguides axis.
The FEKO mode shape for this 180 degree phase shift on the lateral conical walls is not axisymmetric. This appears to be a consequence of the asymmetry imposed by the lateral waveguides that distort what would have otherwise been an axisymmetric mode shape.
_______
Can't comment more than that as I did not find out more information about what particular FEKO module simulation was used (is the FEKO Finite Difference in time and space being used? or is it the FEKO Boundary Element Method (which the author calls Method of Moments) ?, or is the FEKO Finite Element simulation being used. Many questions ...
Here is a run with the dual waveguide Cu drude model of the E components in December. tell me what you see.
One thing is apparent with the dual waveguides (hopefully with the direct waveguide design the phases as well), plus the tune chamber, is I can control and generate multiple modes and how they form and propagate or not.
https://drive.google.com/folderview?id=0ByMNWRlWDxlxYXRRV2JjWE1Pb1U&usp=sharing
Shell
Added
Also if you look at the arrows into the waveguides you'll see the RF insertion was not the same as my model. They used the endplate of the waveguide instead of the side wall. This will want to produce a TM mode.
1) A Meep output labeled with labels that are not readily understood by a general reader "BEZ" ,"SEZ", what does B, and S and Z mean?. I guess that BE and SE may stand for big and small ends, and that Z stands for the z axis being perpendicular to those surfaces ?
What does SEZ vueEx mean ? does that mean the electric field in the x direction and hence parallel to the Small End? How can that have a non-zero value at the small end?
By contrast, the physical significance of the FEKO model is much easier to readily digest:
2) FEKO readily shows the fields on the lateral conical walls. FEKO shows the truncated cone, so one does not have to guess what is what: it is clear in FEKO what is the small end, what is the big end. The Meep model does not show the truncated cone or the conical walls.
3) FEKO shows the electromagnetic fields in numerical SI units that one can relate to. Meep electromagnetic field images are being shown without a conversion ribbon to ascertain the numerical magnitude of the electromagnetic fields (and when it has been shown in the past, Meep uses dimensionless units that frequently are not converted to physical SI units) . Hence I cannot tell what is the significance of what is being shown by Meep, since numerical values are not being shown, nor are SI units being shown for the Meep figures.
4) What is the location of a picture labeled like SEZ_vueEx_t12 for example?
Cannot go any further until one knows the location of the images, the orientation of the axes, and what is the magnitude of the fields being shown by Meep, to know their significance. If SEZ_vueEx is the electric field in the x direction parallel to the end plate, measured at the end plate, then the pictures should show zero. Otherwise the boundary conditions are not being correctly modeled...
The tangential Electric Field will always be zero on a metal surface. This is because the free charge will swim around and cancel it out, simply by the attractive nature of charge.
So,
1) either the boundary conditions are not being correctly satisfied, in which case nothing makes sense
or
2) SEZ_vueEx is not the electric field in a direction parallel to the small end, in which case how is one supposed to know in which direction are the axes ? (what is the meaning of Z in SEZ ?)
or
3) SEZ_vueEx is NOT being shown at the small end, in which case I, or the readers can have NO idea of where it is being shown
or
4) SEZ_vueEx is practically zero, and if this is practically zero neither I nor any reader can tell what is practically significant or almost zero, since the Meep results are not shown with any numerical value for somebody to know what is going on.
In either case, it is an enigma how to make sense of these Meep output images (without further information) while the FEKO images are intuitively obvious, as the whole truncated cone is being shown, and as the numerical value of the fields is being shown in SI units for the FEKO solution.
In any case, I don't recognize the mode shape that was expected: TE013 in any of these Meep images. -
#1850 by RotoSequence on 17 Jan, 2016 18:27
-
Was there some kind of recent change made less than an hour ago. I ask because I was not allowed to see page 93 until I formally logged in which was not required 45 minutes or so ago. The error was "Only registered members are allowed to view this area, please login".
IMHO, if this was not some fluke. Would this not be a bad idea to do since it was not required to be a member or formally login to gain access to these Forum threads in the past? For viewing purposes.
Don
Nothing nefarious; the forums were set to user-only mode to cope with the influx of traffic from today's SpaceX launch. -
#1851 by StrongGR on 17 Jan, 2016 19:24
-
"A question with no answer" (acknowledgment to NSF user "StrongGR", Dr. Marco Frasca)
...
Wikipedia (https://en.wikipedia.org/wiki/Alcubierre_drive#Experiments) states: <<In 2013, the Jet Propulsion Laboratory published results of a 19.6-second warp field from early Alcubierre-drive tests under vacuum conditions>> but it shows no reference to support this statement. The only such experiments I'm aware of are the ones by Dr. White's group at NASA Johnson Eagleworks Lab instead of at JPL (https://en.wikipedia.org/wiki/White%E2%80%93Juday_warp-field_interferometer#Results).
The question has no answer yet but the idea to use strong e.m. fields to manipulate space-time is a real hope for the future with respect to other "exotic" proposals. Still waiting to hear from EW. -
#1852 by rfmwguy on 17 Jan, 2016 19:28
-
Elon musk tweeted 1st stage tipped over after leg failed to lock on sea pad landing. Satellite successfully deployed. Interesting new stuff from L2 section here.Was there some kind of recent change made less than an hour ago. I ask because I was not allowed to see page 93 until I formally logged in which was not required 45 minutes or so ago. The error was "Only registered members are allowed to view this area, please login".
IMHO, if this was not some fluke. Would this not be a bad idea to do since it was not required to be a member or formally login to gain access to these Forum threads in the past? For viewing purposes.
Don
Nothing nefarious; the forums were set to user-only mode to cope with the influx of traffic from today's SpaceX launch.
http://forum.nasaspaceflight.com/index.php?topic=37596.120 -
#1853 by TheUberOverLord on 17 Jan, 2016 19:33
-
Was there some kind of recent change made less than an hour ago. I ask because I was not allowed to see page 93 until I formally logged in which was not required 45 minutes or so ago. The error was "Only registered members are allowed to view this area, please login".
IMHO, if this was not some fluke. Would this not be a bad idea to do since it was not required to be a member or formally login to gain access to these Forum threads in the past? For viewing purposes.
Don
Nothing nefarious; the forums were set to user-only mode to cope with the influx of traffic from today's SpaceX launch.
Never thought was for nefarious ("extremely wicked or villainous; iniquitous") reasons.
That said. One needs to have knowledge that this is done at times or be clairvoyant as a visitor ("Non member") here that things like that even take place. I've been here since thread 1 and never knew things like that are/were done, from time to time.
At least visitors now know ("Later, when they can read this") that this does take place from time to time and that soon they can come back and do some reading here. Without needing to become a member, if they so choose.
Thanks
Don
-
#1854 by Cinder on 17 Jan, 2016 20:36
-
Guests could be funneled and restricted to viewing this thread meanwhile: http://forum.nasaspaceflight.com/index.php?topic=31697.0
-
#1855 by SeeShells on 17 Jan, 2016 21:32
-
I see:
1) A Meep output labeled with labels that are not readily understood by a general reader "BEZ" ,"SEZ", what does B, and S and Z mean?. I guess that B and S may stand for big and small ends, and that Z stands for the z axis being perpendicular to the surface ?
What does SEZ vueEx mean ? does that mean the electric field parallel to the Small End? How can that have a non-zero value at the small end?
By contrast, the physical significance of the FEKO model is much easier to readily digest:
2) FEKO readily shows the fields on the lateral conical walls. FEKO shows the truncated cone, so one does not have to guess what is what: it is clear in FEKO what is the small end, what is the big end. The Meep model does not show the truncated cone or the conical walls.
3) FEKO shows the electromagnetic fields in numerical SI units that one can relate to. Meep electromagnetic field images are being shown without a conversion ribbon to ascertain the numerical magnitude of the electromagnetic fields (and when it has been shown in the past, Meep uses dimensionless units that frequently are not converted to physical SI units) . Hence I cannot tell what is the significance of what is being shown by Meep, since numerical values are not being shown, nor are SI units being shown for the Meep figures.
4) What is the location of a picture labeled like SEZ_vueEx_t12 for example?
Cannot go any further until one knows the location of the images, the orientation of the axes, and what is the magnitude of the fields being shown by Meep, to know their significance. If SEZ_vueEx is the electric field in the x direction parallel to the end plate, measured at the end plate, then the pictures should show zero. Otherwise the boundary conditions are not being correctly modeled...
The tangential Electric Field will always be zero on a metal surface. This is because the free charge will swim around and cancel it out, simply by the attractive nature of charge.
So,
1) either SEZ_vueEx is NOT being shown at the small end, in which case I, or the readers can have NO idea of where it is being shown
or
2) SEZ_vueEx is practically zero, and if this is practically zero neither I nor any reader can tell what is practically significant or almost zero, since the Meep results are not shown with any numerical value for somebody to know what is going on.
In either case, it is an enigma how to make sense of these Meep output images (without further information) while the FEKO images are intuitively obvious, as the whole truncated cone is being shown, and as the numerical value of the fields is being shown in SI units for the FEKO solution.
In any case, I don't recognize the mode shape that was expected: TE013 in any of these Meep images.
I was never after TE013 Dr. Rodal. The only person I know of seeking that mode is TT. TT is pushing because Shawyer told him it is the mode to shoot for.
I will agree that FEKO has some very good points and I even understand there are modules that support the GPU which could mean a nice performance boost. Understand I'm using the tools I have and had access to.
On the mode shape being shown you will as I did look at it as I have, a hybrid mode. The SEZ_vueEx is on the small end but you see a mix of two modes.
On the FEKO antenna placement. The source was placed at the very end of the waveguide cavity instead of a dipole on the side ref: http://www.wikarekare.org/Antenna/Waveguide.html This will cause unexpected effects if not modeled correctly. You know this Dr. Rodal.
-
#1856 by Rodal on 17 Jan, 2016 21:57
-
[...
I was never after TE013 Dr. Rodal. The only person I know of seeking that mode is TT. TT is pushing because Shawyer told him it is the mode to shoot for.
I will agree that FEKO has some very good points and I even understand there are modules that support the GPU which could mean a nice performance boost. Understand I'm using the tools I have and had access to.
On the mode shape being shown you will as I did look at it as I have, a hybrid mode. The SEZ_vueEx is on the small end but you see a mix of two modes.
On the FEKO antenna placement. The source was placed at the very end of the waveguide cavity instead of a dipole on the side ref: http://www.wikarekare.org/Antenna/Waveguide.html This will cause unexpected effects if not modeled correctly. You know this Dr. Rodal.
I thought you thought the mode shape was TE013
because:
1) The FEKO files that you referred to in your e-mail have been labeled as "SeeShell TE01" (please look at the labels in https://drive.google.com/folderview?id=0B6juR48k_XoTVi1FWDc4R2pMWTA&usp=sharing )
2) When discussing what did you expect that the thermal camera was going to show in your present experiment, I recalled you answered that you expected a TE013 mode. Is my memory correct? If it is, is the present experiment different from the model in this FEKO files, or what is the reason for expecting the thermal camera to show TE013?
____________
The Meep image files do not make any sense to me, for the reasons previously pointed out.
A "hybrid mode" or any mode shape for that matter cannot result in an electric field parallel to the copper wall, at the copper small end plate. Either the Meep model is not correctly modeling the boundary conditions, in which case the whole Meep model is complete nonsense, or SEZ_vueEx is not what one would expect. Not way for me to know since the numerical fields are not shown, and the directions are not specified.
So, what is SEZ_vueEx ? in what direction are the X, Y and Z axes? How can SEZ_vueEx be at the small end and not be zero???
Isn't the inner wall made of a metal ?
If SEZ_vueEx is showing a very small number, how can you tell what images in the Meep file correspond to practically zero values and which ones correspond to significant values ?
By comparison, the FEKO model is a pleasure to see, because even though it is mislabeled (as TE01), one can tell immediately what is going on (it is TM112), and that boundary conditions are being respected in the FEKO model. -
#1857 by SeeShells on 17 Jan, 2016 22:43
-
I had little control over what was modeled or presented only was asked for the dimensions of the cavity in the FEKO model.[...
I was never after TE013 Dr. Rodal. The only person I know of seeking that mode is TT. TT is pushing because Shawyer told him it is the mode to shoot for.
I will agree that FEKO has some very good points and I even understand there are modules that support the GPU which could mean a nice performance boost. Understand I'm using the tools I have and had access to.
On the mode shape being shown you will as I did look at it as I have, a hybrid mode. The SEZ_vueEx is on the small end but you see a mix of two modes.
On the FEKO antenna placement. The source was placed at the very end of the waveguide cavity instead of a dipole on the side ref: http://www.wikarekare.org/Antenna/Waveguide.html This will cause unexpected effects if not modeled correctly. You know this Dr. Rodal.
I thought you thought it was TE013 because:
1) The FEKO files that you referred to in your e-mail have been labeled as TE01 (please look at the labels in https://drive.google.com/folderview?id=0B6juR48k_XoTVi1FWDc4R2pMWTA&usp=sharing ) instead of TM112
2) I recalled that when discussing what did you expect that the thermal camera was going to show in your experiment, I recalled you answered that you expected a TE013 mode. Is my memory correct? If it is, is the present experiment different from the model in this FEKO files, or what is the reason for expecting the thermal camera to show TE013?
____________
The Meep image files do not make any sense to me, for the reasons previously pointed out.
A "hybrid mode" or any mode shape for that matter cannot result in an electric field parallel to the copper wall, at the copper wall. Either the Meep model is not correctly modeling the boundary conditions, in which case the whole Meep model is complete nonsense, or SEZ_vueEx is not what one would expect. Not way for me to know since the numerical fields are not shown, and the directions are not specified.
So, what is SEZ_vueEx ? in what direction are the X, Y and Z axes? How can SEZ_vueEx be at the small end and not be zero???
If SEZ_vueEx is showing a very small number, how can you tell what images in the Meep file correspond to practically zero values and which ones correspond to significant values ?
By comparison, the FEKO model is a pleasure to see, because even though it is mislabeled, one can tell immediately what is going on, and that boundary conditions are being respected in the Meep model.
I've requested a version of FEKO to run and confirm my cavity actions. Waiting for a email from them to be able to download.
I stated I was after TE012.
As far as meep goes other than pulling out the CSV file and log files you have little idea of values.
Didn't you and aero come up with a agreed on X, Y, Z coordinate system where the frustum as viewed sitting flat on the large end plate? See attachment
-
#1858 by Rodal on 17 Jan, 2016 22:53
-
...
I had little control over what was modeled or presented only was asked for the dimensions of the cavity in the FEKO model.
I've requested a version of FEKO to run and confirm my cavity actions. Waiting for a email from them to be able to download.
I stated I was after TE012.
As far as meep goes other than pulling out the CSV file and log files you have little idea of values.
Didn't you and aero come up with a agreed on X, Y, Z coordinate system where the frustum as viewed sitting flat on the large end plate? See attachment
According to the convention we had agreed, which is the same as the picture you show, then SEZ_vueEx should be the Electric field in the direction parallel to the end plate, and measured at the small end (SE).
But then, the SEZ_vueEx (and other) images shown in the Meep files you linked to do not make any sense. No mode shape can result in an electric field parallel to a metal, measured at the metal.
BOUNDARY CONDITION FOR AN ELECTRIC FIELD: The tangential Electric Field will always be zero on a metal surface. This is because the free charge will swim around and cancel it out, simply by the attractive nature of charge.
Either the Meep model is not correctly modeling the boundary conditions, in which case the whole Meep model is complete nonsense, or SEZ_vueEx has a value very close to zero. If SEZ_vueEx is showing a very small number, there is no way to tell what the images mean: they have no numerical field values and there is no way to tell which images are significant. From your answer << have little idea of values.>> you cannot tell either, since the Meep files do not show the numerical fields.
So, there is no way to tell from these Meep images which ones make any sense, except to tell that SEZ_vueEx for example does not make any sense and therefore there is no way to tell what is going on, much less to tell what mode shape is present.
-
#1859 by Notsosureofit on 17 Jan, 2016 22:57
-
I figure this may be of interest to @Rodal (you dig Finite element analysis) and @Notsosureofit (your hypothesis featuring an accelerated frame of reference).
http://people.clarkson.edu/~nanosci/jse/B/inpress/vaish.pdf
Yes, that is exactly what the Notsosureofit hypothesis is based on.
- add another grounded fr4 board to small end, metal tape, whatever...to increase cavity reflectivity. Repeat as needed. Measuring FS in all orientations is an excellent idea.
I will appreciate any advice and hints.
because: