Author Topic: EM Drive Developments - related to space flight applications - Thread 5  (Read 941367 times)

Offline D_Dom

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Thread topic is EM Drive, just sayin'.
Space is not merely a matter of life or death, it is considerably more important than that!

Offline Mulletron

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A shout out from PBS.

Yes I'm still alive. I'm wrapped around gravitoelectromagnetism (the theory(ies) is/are a mess) and whether photons with effective mass within waveguide can create GEM fields which in turn influence the motion of moving air molecules via the Gravitational Lorentz Force within the frustum. I'm devoting all of my time to understanding the hypothetical graviphoton. Yes I'm in way over my head. 😁

I get the sense that GR is completely correct of course but it is not the end. There is much more to learn.

And my experimental efforts are on hold until I stop failing. I really need a better high power solid state solution which I can power with DC and my battery solution is not going well. I'm probably going to have to wait until I get back home to America.
And I can feel the change in the wind right now - Rod Stewart

Offline rfmwguy

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A shout out from PBS.

Yes I'm still alive. I'm wrapped around gravitoelectromagnetism (the theory(ies) is/are a mess) and whether photons with effective mass within waveguide can create GEM fields which in turn influence the motion of moving air molecules via the Gravitational Lorentz Force within the frustum. I'm devoting all of my time to understanding the hypothetical graviphoton. Yes I'm in way over my head. 😁

I get the sense that GR is completely correct of course but it is not the end. There is much more to learn.

And my experimental efforts are on hold until I stop failing. I really need a better high power solid state solution which I can power with DC and my battery solution is not going well. I'm probably going to have to wait until I get back home to America.
Safe travels. Panasonic is experimenting with solid state cooking "magnetrons" not there yet I'm afraid.

Not sure about others, but think we need some null data to add to emdrive.wiki to show where someone has gone before and not hit paydirt yet. Consider this and let me know if you agree. Could save some grief down the road.

Offline Mezzenile

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That's a good idea and time permitting I might do one. Here is another from MIT that reconstructs acoustics wave patterns from an object through glass with video of that remote object. Video patterns are simply vibrations and movement of a surface. I was thinking it would be a great way to monitor movement of not only movements in air, but through a vacuum chamber window.
This reminds me of the attempts to find the voice of the craftsman who was registered in ceramics while he was working on his potter's wheel.
This would return the voices of potters living in the days of antiquity !  :)

Offline Prunesquallor

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That's a good idea and time permitting I might do one. Here is another from MIT that reconstructs acoustics wave patterns from an object through glass with video of that remote object. Video patterns are simply vibrations and movement of a surface. I was thinking it would be a great way to monitor movement of not only movements in air, but through a vacuum chamber window.
This reminds me of the attempts to find the voice of the craftsman who was registered in ceramics while he was working on his potter's wheel.
This would return the voices of potters living in the days of antiquity !  :)

Ah, the "Lazarus Bowl" (X-Files).
Retired, yet... not

Offline Prunesquallor

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It might look as if someone else had do something like this, way before us. This is just one small step, isn't it?
Little off topic but it's the driving reason we are all here.

http://www.theatlantic.com/science/archive/2015/10/the-most-interesting-star-in-our-galaxy/410023/

Cross-referenced to the last few pages of this thread:  http://forum.nasaspaceflight.com/index.php?topic=16581.0  One of the authors of the paper being cited in The Atlantic is actively discussing the Kepler team findings on the thread, so hit him up with questions (read the paper first please!!! http://arxiv.org/pdf/1509.03622v1.pdf).

The paper is an excellent analog to EMDrive done right, IMHO. It starts by describing an unusual phenomenon, examines and eliminates the potential for measurement error, examines and eliminates "traditional" explanations and describes future investigations that should be performed to help figure out what is going on. It even involves citizen scientists (a much better term than "amateurs") and "DiY" analysis.

Kudos to everyone involved.
« Last Edit: 10/16/2015 10:54 AM by Prunesquallor »
Retired, yet... not

Offline rfmwguy

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Guess where I'll be going this weekend: http://bucyruscopperkettle.com/

Online SeeShells

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Guess where I'll be going this weekend: http://bucyruscopperkettle.com/
TOTALLY forgot about this place, knew it was there when I lived in Ohio. What a great idea!!!!

Offline Notsosureofit

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Yes I'm still alive. I'm wrapped around gravitoelectromagnetism (the theory(ies) is/are a mess) and whether photons with effective mass within waveguide can create GEM fields which in turn influence the motion of moving air molecules via the Gravitational Lorentz Force within the frustum. I'm devoting all of my time to understanding the hypothetical graviphoton. Yes I'm in way over my head. 😁

I get the sense that GR is completely correct of course but it is not the end. There is much more to learn.

And my experimental efforts are on hold until I stop failing. I really need a better high power solid state solution which I can power with DC and my battery solution is not going well. I'm probably going to have to wait until I get back home to America.

Glad to hear it ! (you being alive, that is)

Reminded me that I meant to comment (back a bit!) when the topic was Nother's Theorem and separate conservation laws for energy and momentum.  I think required reading should be:

Sachs, M.,"The Mach Principle and the Origin of Inertia
From General Relativity", see: mendelsachs.com/wp-content/uploads/articles/the-mach-principle.pdf


"I am not aware that Einstein gave any explicit reason for this requirement in his writings. However, I believe that it can be based on the empirical requirement that the (local) flat spacetime limit of the general field theory in a curved spacetime, must include laws of conservation – of energy, linear momentum and angular momentum. For, according to Noether’s theorem,4 the analyticity of the field solutions is a necessary and a sufficient condition for the existence of these conservation laws. Strictly, there are no conservation laws in general relativity because, covariantly, a ‘time rate of change’ of some function of the spacetime coordinates in a curved spacetime cannot be separated from the rest of the formulation that can go to zero. Thus, the laws of conservation apply strictly only to the local domain. The conservation laws are then a local limit of global laws in general relativity."

Havn't even had time to follow up though, barley even able to read the forum at the moment.

PS:  I do have, of course, a good selection of vacuum chambers if we ever get that far....

Offline Space Time Engineer

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That's a good idea and time permitting I might do one. Here is another from MIT that reconstructs acoustics wave patterns from an object through glass with video of that remote object. Video patterns are simply vibrations and movement of a surface. I was thinking it would be a great way to monitor movement of not only movements in air, but through a vacuum chamber window.
This reminds me of the attempts to find the voice of the craftsman who was registered in ceramics while he was working on his potter's wheel.
This would return the voices of potters living in the days of antiquity !  :)

Ah, the "Lazarus Bowl" (X-Files).


Actually this concept was utilized frequently in the "Fringe" TV series (getting voice data from glass).  I do chuckle as well that Walter Bishop was always talking about "resonant frequencies" while opening portals to alt universe.......  A little far fetched EMDrive humor for this morning.....

Dr B
« Last Edit: 10/16/2015 04:54 PM by Space Time Engineer »

Offline DaCunha

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Dear all

I thought this could be interesting for other DIYers.

I am manufacturing a self-made  two-chamber klystron in my local FabLab. I will manufacture the buncher and catcher cavities with the help of a 3D printer and I am going to order tungsten wires for the electron gun filament. The accelerating anodes will be made of a circular aperture electrode The most difficult/expensive part will be the helmholtz coil for the external e- beam confining axial magnetic field.

The bandwidth will be very limited as for all klystron, so you guys have to fit your geometries to it if you want to use it, but several tens of kW should be realistic if operated as an oscillator with chamber feedback.

Once finished I would lend the klystron to all other DIYers here!

I'd wish I had more time to spend on this but I am only free on weekends.

You either don't have the money or you don't have the time, when you're young.

If you find grammar or spelling mistakes in the text above, you may keep them ;-)


Offline Stormbringer

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There was some discussion of quantum fluctuations in earlier iterations of this thread such as with Dr White's QVPT thing. Well here is something that will allow someone investigating this hypothesis to tell what those sneaky fluxes are up to:

http://www.sciencedaily.com/releases/2015/10/151013103115.htm

When antigravity is outlawed only outlaws will have antigravity.

Offline Notsosureofit

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There was some discussion of quantum fluctuations in earlier iterations of this thread such as with Dr White's QVPT thing. Well here is something that will allow someone investigating this hypothesis to tell what those sneaky fluxes are up to:

http://www.sciencedaily.com/releases/2015/10/151013103115.htm

This is the superconducting version of a very old experiment. (did this as a teenager w/ war-surplus gear, great fun!)

By going to a superconductor, the usual resistive losses are eliminated and the variation in Q can be blamed on the vacuum fluctuations, but the influence of the reflected (virtual ?) wave remains the same.

They have another very interesting experiment using a superconducting-transition ring resonator showing time-reversal symmetry-broken states, which could also be relevant.

Håkansson, M., Löfwander, T. and Fogelström, M. (2015) Spontaneously broken time-reversal symmetry in high-temperature superconductors. Nature Physics (1745-2473). Vol. 11 (2015), 9, pp. 755-760.
dx.doi.org/10.1038/nphys3383
 

Online SeeShells

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There was some discussion of quantum fluctuations in earlier iterations of this thread such as with Dr White's QVPT thing. Well here is something that will allow someone investigating this hypothesis to tell what those sneaky fluxes are up to:

http://www.sciencedaily.com/releases/2015/10/151013103115.htm

This is the superconducting version of a very old experiment. (did this as a teenager w/ war-surplus gear, great fun!)

By going to a superconductor, the usual resistive losses are eliminated and the variation in Q can be blamed on the vacuum fluctuations, but the influence of the reflected (virtual ?) wave remains the same.

They have another very interesting experiment using a superconducting-transition ring resonator showing time-reversal symmetry-broken states, which could also be relevant.

Håkansson, M., Löfwander, T. and Fogelström, M. (2015) Spontaneously broken time-reversal symmetry in high-temperature superconductors. Nature Physics (1745-2473). Vol. 11 (2015), 9, pp. 755-760.
dx.doi.org/10.1038/nphys3383
"This is the superconducting version of a very old experiment. (did this as a teenager w/ war-surplus gear, great fun!)"

I am so impressed, all I did was build a radio and TV. You were doing superconducting experiments!

The longer I'm here the more humble I become, what a wonderful brilliant and great group you all are. You have given me the greatest gift of hope, hope that we will not only solve this conundrum but make it better, finer and ultimately of value to our future generations.

Just a pat on the back to all...

Shell

Offline original_mds

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You may want to step through the distance between the end plates and see the resonances. It will be interesting to compare. Also did you see the parts bins in the pictures of the shop, that's just part of all of them... ::) yes I have spares parts and beads

Just back from daily rad. Will do the analysis runs this evening or early tomorrow and report back.

Take apart the bottom maggie assy where the heater leads are. Should find an inline filter on each lead. Might as well remove them from the dead maggie and put them in series on the -DC feed from your inverter.

I mentioned this earlier and am not sure if it was missed or ignored.  Can a meep run be done without having the end cap being perfectly axially aligned with the frustrum body?  I can't help but reflect on all the geometry discussions that have occurred, but we still don't have any idea about how good the alignment has to be to get the modes to stabilize.  E.g does the alignment have to be within a degree, or a thousandth of a degree?  Does meep even have the resolution to be able to evaluate this type of sensitivity?

Online SeeShells

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You may want to step through the distance between the end plates and see the resonances. It will be interesting to compare. Also did you see the parts bins in the pictures of the shop, that's just part of all of them... ::) yes I have spares parts and beads

Just back from daily rad. Will do the analysis runs this evening or early tomorrow and report back.

Take apart the bottom maggie assy where the heater leads are. Should find an inline filter on each lead. Might as well remove them from the dead maggie and put them in series on the -DC feed from your inverter.

I mentioned this earlier and am not sure if it was missed or ignored.  Can a meep run be done without having the end cap being perfectly axially aligned with the frustrum body?  I can't help but reflect on all the geometry discussions that have occurred, but we still don't have any idea about how good the alignment has to be to get the modes to stabilize.  E.g does the alignment have to be within a degree, or a thousandth of a degree?  Does meep even have the resolution to be able to evaluate this type of sensitivity?
Meep can do it but it's the real world tests that will make it apparent the level of co-planar that's going to be needed.

I was concerned of the alignments of the two plates. To try and keep the top plate aligned with the bottom I've done several things. One was to have the copper water jet cut to better than .001". Second the bottom plate is flat to better than .001".

The top tuning chamber is the concern with the small end plate. I'm building it to make sure the tuning cylinder is perpendicular to the frustum by using a simple laser alignment. (I'll post pictures when I do it). On the top of the small top plate I have three long sections of PTFE pushed out to the side walls to keep it from tilting during tuning and co-planar to the bottom plate. Testing will tell how well that aligns the whole system.

Shell
« Last Edit: 10/17/2015 04:46 PM by SeeShells »

Offline Notsosureofit

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"This is the superconducting version of a very old experiment. (did this as a teenager w/ war-surplus gear, great fun!)"

I am so impressed, all I did was build a radio and TV. You were doing superconducting experiments!

Shell

Sorry about that Shell.  Was doing the non-superconducting, room temperature version back then.....

Offline aero

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You may want to step through the distance between the end plates and see the resonances. It will be interesting to compare. Also did you see the parts bins in the pictures of the shop, that's just part of all of them... ::) yes I have spares parts and beads

Just back from daily rad. Will do the analysis runs this evening or early tomorrow and report back.

Take apart the bottom maggie assy where the heater leads are. Should find an inline filter on each lead. Might as well remove them from the dead maggie and put them in series on the -DC feed from your inverter.

I mentioned this earlier and am not sure if it was missed or ignored.  Can a meep run be done without having the end cap being perfectly axially aligned with the frustrum body?  I can't help but reflect on all the geometry discussions that have occurred, but we still don't have any idea about how good the alignment has to be to get the modes to stabilize.  E.g does the alignment have to be within a degree, or a thousandth of a degree?  Does meep even have the resolution to be able to evaluate this type of sensitivity?

Can it be done? Of course it can be done, meep source code is available, meep is a numerical algorithm running with a geometric model (in our case). Any reasonable model you care to take the time to construct in a meep control file can be run. Here are the components you have to work with in native mode.

http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#geometric-object

Of course if needed, you can add stuff using the C++ language and recompile.

But the first question I have is, "Why would you want to model misalignment, what is to be gained?"
Retired, working interesting problems

Quote
But the first question I have is, "Why would you want to model misalignment, what is to be gained?"

he wants to see how good the alignement has to be to get the modes to stabilize.

Offline original_mds

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I mentioned this earlier and am not sure if it was missed or ignored.  Can a meep run be done without having the end cap being perfectly axially aligned with the frustrum body?  I can't help but reflect on all the geometry discussions that have occurred, but we still don't have any idea about how good the alignment has to be to get the modes to stabilize.  E.g does the alignment have to be within a degree, or a thousandth of a degree?  Does meep even have the resolution to be able to evaluate this type of sensitivity?

Can it be done? Of course it can be done, meep source code is available, meep is a numerical algorithm running with a geometric model (in our case). Any reasonable model you care to take the time to construct in a meep control file can be run. Here are the components you have to work with in native mode.

http://ab-initio.mit.edu/wiki/index.php/Meep_Reference#geometric-object

Of course if needed, you can add stuff using the C++ language and recompile.

But the first question I have is, "Why would you want to model misalignment, what is to be gained?"
As many of us have experienced first hand, the real world tends to rarely (never) have perfect builds.  Fortunately, most systems have some margin for imperfections.  For cutting edge stuff, not having a good handle on what that margin is can result in a lot of wasted time, effort, and cash.

For example, a project I was working on last year spent millions on trying to trace down the source of an intermittent issue that was threatening the entire program.  Similar to the EM builds, it wasn't possible to take measurements of the parameters we wanted while the device was in use, so there was a heavy reliance on FEA modeling.  Our perfect models showed some potential weaker points in the design, but nothing that was the clear culprit. We went through several fix/test cycles, but the issue remained intermittent. 

Ultimately, it appears the issue was a very minor misalignment that led to asymetries in the forces being applied to the uni, resulting in its destruction.  Tolerances were similar to Seashell's work, but we found inconsistencies in measurements when using different measurement systems.  When we did additional runs with the misalignment modeled, it quickly became obvious that the design was quite sensitive  to alignment.  Tightening the spec and increasing the number of data points when checking alignment resulted in perfect performance ever since.

In the EM drive, every model that has been discussed for attempting to establish the best modes assumes perfect alignment.  IIRC, Seashell's current design is supposed to have an absurdly high Q.  How sensitive is it to alignment?  AFAICT, we have no idea.  Given a few more simulation data points, we may find that her chosen build tolerance gives a range of possible Q spanning several orders of magnitude.  Or, we may see that she can increase her build tolerance 10x with little expected impact on the results, making her build easier to accomplish.

I'd like to chip in on the modeling effort, but have some outside projects on the house that need to get done before it gets too cold.  I may have more time when the snow flies.

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