Author Topic: EM Drive Developments - related to space flight applications - Thread 6  (Read 1493658 times)

Offline rfmwguy

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The top plate is 12 square inches in case anyone wants to put solid number together

Offline SteveD

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Urm, can we establish a floor above which it becomes unlikely that a device not specifically engineered to produce thrust will be able to reach.  Seems like there should be a point, on a N/kw basis where you need some kind of propeller or rocket nozzle.  An efficiency beyond that point, and something is happening. 

Offline rfmwguy

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Unless someone demonstrates or points out a potential error source that approaches a triple-digit micronewton level, I will not chase those phantoms. Lorentz force in the horizontal axis falls into this category as does thermal plume turbulence (fluid analysis), imho. Show me a non-jet down force test result or example and I may take that off of my phantom list. There were no jets identified on the top plate emanating from the mag per my thermal scans, nor was there uneven heating of any of the outer surfaces; a clear sign of air jets.

So, statistics are most straight-forward way to analyze beam displacement variances between mag on and mag off cycles. No other error source hypothesis approaches the force level needed to interrupt the thermal lift track; Lorentz, air jets, plume turbulence, thermal expansion, etc., etc.

If anyone has other ideas...I'm all ears and will test for them if funding allows next year.

Well I had thought that the transformer hum might have vibrated the hot air trapped in the heat sink chamber, causing more of it to spill out, reducing lift.  Would think that this would have shown up clearly on the thermal camera though.  Best was I can think of to test for this would be simply proceeding as planned.  If you remove the magnetron from the top of the thing and it goes down more with higher Q . . . well that's interesting.

I think the big problem with mangetrons are that their outputs can take a random walk.  Sometimes you get very little in resonance and sometimes you get more.  Statistics would seem to be an excellent way of dealing with an rf source given to random walks. 
 
The transformer is in a separate box several feet away, not on the frustum. The small box on top is simple RLC circuitry, tapping the 4kV line to help power the filament. No transformers there.

Offline SteveD

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I don't believe gyroscopic precession can be used to explain Shawyer's video.  The pump is not spinning fast enough for gyroscopic effects.   But just having a motor mounted with its shaft parallel to the rotational axis of the apparatus is enough to start it rotating.   Several years ago I mounted a motor on a rotating table.   When the motor was spun up the table rotated.  When the motor was switched off the table rotated back to its original position.  We don't now enough about Shawyers apparatus to be able to analyze what is happening.   That's why the focus has been on DIY experiments.

Hum, didn't the rotation start like 20 minutes into the test?  Would think the fans on the laptop would be a more likely cause.

Offline SeeShells

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Except therm vids show little heating below mag
One thing that's important that I didn't do the first time in my post testing prior to a full scale run was monitor the spectrum of the magnetron with my Spectrum Analyzer. It can show when the magnetron powers on, reaches lock or not and even shifting out of lock during a run.

I will be doing so in the next tests because that time stamp data can be used to overlay any thrust or lack of thrust data from the digital acceleration or digital force profiles.

Shell

Offline rfmwguy

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Except therm vids show little heating below mag
One thing that's important that I didn't do the first time in my post testing prior to a full scale run was monitor the spectrum of the magnetron with my Spectrum Analyzer. It can show when the magnetron powers on, reaches lock or not and even shifting out of lock during a run.

I will be doing so in the next tests because that time stamp data can be used to overlay any thrust or lack of thrust data from the digital acceleration or digital force profiles.

Shell
Couple of pages back, I mentioned overlapping windows on the laptop screen with the smaller window being the spec an trace. Screen recording software can then lock these 2 together output one avi file. Worked well for me.

Offline Kenjee

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Maybe?

Offline aero

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It is explained by thermal convection on a plate that is heated above the plate (by the magnetron).  Convection currents are generated whereby the hotter air above the plate experiences a buoyancy force going upwards.  As a result of this the plate is virtually "sucked up" experiencing a lift force and the colder air above the hot air goes downward to occupy the space previously occupied by the hotter air.  This convection is time-dependent, the fluid flow is not laminar, but it involves vortices above and below the plate.  Vortex shedding takes place intermittently.  The lift experienced by the plate and by the hot magnetron partially open cavity (due to their own buoyancy) is a chaotic function of time (due to the nonlinear nature, time dependent nature of the Navier-Stokes equation, particularly in this low Reynolds number regime).  Due to the low Reynolds number regime being above Stokes flow, in an intermediate region of the Navier-Stokes flow which is difficult to model (unless done numerically) the time dependence of the convection and vortex shedding is complicated, involving chaotic fluctuations with time.  The turning ON and OFF the magnetron further complicates the time-dependent nature of these fluctuations.

The chaotic time dependence of the lift force, and its direction is not subject to intuition any more than you can intuit the time dependence and direction of lift of a wing in the region of stall, beyond the critical angle of attack.

Just a thought - It is well understood that turbulent flow is very difficult to model in detail. However, streamlining is a proven technique to minimize turbulence in airflow around high speed vehicles, cars and aircraft, resulting in near total laminar flow. Laminar flow is much more amenable to mathematical modelling.

Is it within the reach of a DYI'ers to construct a very low mass attachment for each end of the frustum to streamline the apparatus and thereby significantly reducing or eliminating turbulence?

@Kenjee - cross posted, we're thinking along the same lines.
« Last Edit: 12/18/2015 07:12 pm by aero »
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Offline Rodal

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It is explained by thermal convection on a plate that is heated above the plate (by the magnetron).  Convection currents are generated whereby the hotter air above the plate experiences a buoyancy force going upwards.  As a result of this the plate is virtually "sucked up" experiencing a lift force and the colder air above the hot air goes downward to occupy the space previously occupied by the hotter air.  This convection is time-dependent, the fluid flow is not laminar, but it involves vortices above and below the plate.  Vortex shedding takes place intermittently.  The lift experienced by the plate and by the hot magnetron partially open cavity (due to their own buoyancy) is a chaotic function of time (due to the nonlinear nature, time dependent nature of the Navier-Stokes equation, particularly in this low Reynolds number regime).  Due to the low Reynolds number regime being above Stokes flow, in an intermediate region of the Navier-Stokes flow which is difficult to model (unless done numerically) the time dependence of the convection and vortex shedding is complicated, involving chaotic fluctuations with time.  The turning ON and OFF the magnetron further complicates the time-dependent nature of these fluctuations.

The chaotic time dependence of the lift force, and its direction is not subject to intuition any more than you can intuit the time dependence and direction of lift of a wing in the region of stall, beyond the critical angle of attack.

Just a thought - It is well understood that turbulent flow is very difficult to model in detail. However, streamlining is a proven technique to minimize turbulence in airflow around high speed vehicles, cars and aircraft, resulting in near total laminar flow. Laminar flow is much more amenable to mathematical modelling.

Is it within the reach of a DYI'ers to construct a very low mass attachment for each end of the frustum to streamline the apparatus and thereby significantly reducing or eliminating turbulence?

@Kenjee - cross posted, we're thinking along the same lines.

If people insist on using a magnetron...

Yes any of these ideas are better than the NSF-1701 test configuration (the naked magnetron on top of the plate).

Berca had it on the side of the EM Drive (that eliminates the lift from the EM Drive end-plate but still gives lift from the hot magnetron, and it is unsymmetric on Berca's case).

But even better is Shell's idea to remove the magnetron from the top of the EM Drive all together, have the magnetron far away, and feed the EM Drive with dual symmetric waveguides.  Using waveguides has been the proven technique in Meep to excite TE modes.
« Last Edit: 12/18/2015 07:30 pm by Rodal »

Offline X_RaY

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Maybe?
This would reinforce the balloon effect...
I think to separate the magnetron from the cavity (like Shells design) is on of the best possibilities, especially at ambient pressure.
« Last Edit: 12/18/2015 07:55 pm by X_RaY »

Offline SeeShells

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Urm, can we establish a floor above which it becomes unlikely that a device not specifically engineered to produce thrust will be able to reach.  Seems like there should be a point, on a N/kw basis where you need some kind of propeller or rocket nozzle.  An efficiency beyond that point, and something is happening.
Anything beyond the thrust of a photon rocket or on par with a ion engine is a game changer in many many ways.

But here is the kicker, we not even sure if what we're seeing is thrust, maybe masses are being changed somehow, maybe it can't accelerate, just somehow reduce mass? This is why I'm doing acceleration profiles with a moving beam and static pressure readings on the same DUT and test stand. Is there a difference? I don't honestly know.


Shell

Offline Possibles

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Hi Guys...

Been a long time since I have posted here. The place seems to have "Thinned out" somewhat... and gotten down to grass roots. :)

Can someone put a quick summary up? Got to admit I'm a bit fearful of reading through it all. And I'm worn out.

I did have a thought though. And probably the only one that makes sense to me. And its to do with our understanding of space-time. The topic here is "Potential" and how we see it. Let me try to explain, and please remember I'm not Einstein.

Visualize for a moment a Black Hole.  Mathematics breaks down beyond the event horizon, but we can still infer things. The main problem is that everything becomes indistinct. And that is EXACTLY the point. Space and Time become "Potential" They become free of the shackles that our Universe imposes on them.

There is a very interesting viewpoint I have come up with. And there is NO way of testing it. Boiling it down to the absolute core, we as humans perceiving the Universe cannot equate the concept of "Nothingness" unless we have an opposition. Our brains simply cannot and will not do that. Take the logical path of this sentence for example: "Nothingness nothings itself out of existence" It cannot exist without a human definition, so, like God in the Hitchhikers, he gives up and goes away. Because we are the human observers, and we are the problem.
Ergo, we are screwed.

Unless the Universe works the same way we do? Now that would be weird eh? Now. Im going to stop right here, as Chris might get a bit miffed with off topic stuff. And I don't want to interrupt the progress here. Im not sure what to do in this regard. (Perhaps some guidance...some pills?)
 But I do believe we might just be disrupting the POTENTIAL of space-time but not space-time itself. They are two very, very different things. The former is Timeless, and the latter is that instant of creation where our Universe sprung into existence and instantly tried to spring out of it again.

We are the guys and gals stuck in that lattice of instant confusion.

I hope that wasn't too foolish.

Quick mod for clarity. You don't need black hole energies to do things like this. Maybe the best way of looking at the EmDrive is as a "Filter"
« Last Edit: 12/18/2015 09:28 pm by Possibles »

Offline OnlyMe

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Could this effect, in any way, start causing superconductivity in the copper? Is their any possible way that this could happen? I'm not thinking along the lines of Roger Shaywer.  I'm think maybe if their is super conductivity then gravitons could be reflecting off the surface of the copper.

Super conductors of theirselves don't react differently to gravity than anything else.

Drop an apple and a super conductor rock and they fall at the same rate.

Offline Blaine

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Could this effect, in any way, start causing superconductivity in the copper? Is their any possible way that this could happen? I'm not thinking along the lines of Roger Shaywer.  I'm think maybe if their is super conductivity then gravitons could be reflecting off the surface of the copper.

Super conductors of theirselves don't react differently to gravity than anything else.

Drop an apple and a super conductor rock and they fall at the same rate.
Thank you for the reply.  I was actually just taking an idea from this article: http://www.livescience.com/50119-superconductors-physicists-gravity-particles.html
Weird Science!

Offline glennfish

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RE: calculating thermals.

Given any of the DIY designs under consideration...

Assuming resonance is the path ...

Given the magnetrons in play today, what is the easiest way to take a DIY design and just dump heat AND destroy any meaningful resonance?  I have a vision of stuffing steel wool into the frustum as a first approximation, but there might be a simpler way to totally detune a frustum.  Bring the Q as close to zero (one?) as possible.

To me, that would be the cheap and dirty way to get a thermal lift measurement as a baseline data set.

Then, if you tuned for optimal resonance, highest possible Q, you'd have a baseline thermal for comparison.

Critiques?  Ideas?
« Last Edit: 12/18/2015 09:55 pm by glennfish »

Offline Rodal

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Hi Guys...

Been a long time since I have posted here. The place seems to have "Thinned out" somewhat... and gotten down to grass roots. :)

Can someone put a quick summary up? Got to admit I'm a bit fearful of reading through it all. And I'm worn out.

....

The last institutional published experimental report was by Tajmar at the Technische Universität Dresden in Germany.

We are waiting to hear news from NASA regarding:

1) Publication of NASA's Eagleworks EM Drive tests performed in vacuum, including discussion/analysis of thermal expansion effects and effects from forces resulting from the magnetic damper.

2) Confirmation of whether or not a new testing campaign will commence at NASA Glenn to replicate the tests at NASA Johnson (Eagleworks), and if so when are the NASA Glenn results expected to be announced/reported.

Remarkably, Yang (in China) has not published any new results for a considerable amount of time, and her last publication dealt with the considerable thermal effects on her experiments (her paper on temperature vs. time measurements throughout a heated EM Drive using embedded thermocouples).

Concerning Do-It-Yourself experiments, the last experimental report was by RFMWGUY (NSF-1701 test).  We are waiting to hear from Shell on her meticulously and thoroughly designed testing program.

Offline SteveD

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Maybe?
This would reinforce the balloon effect...
I think to separate the magnetron from the cavity (like Shells design) is on of the best possibilities, especially at ambient pressure.

I thought the issue was thermal effects creating the illusion of movement against lift?

Offline SteveD

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Urm, can we establish a floor above which it becomes unlikely that a device not specifically engineered to produce thrust will be able to reach.  Seems like there should be a point, on a N/kw basis where you need some kind of propeller or rocket nozzle.  An efficiency beyond that point, and something is happening.
Anything beyond the thrust of a photon rocket or on par with a ion engine is a game changer in many many ways.

But here is the kicker, we not even sure if what we're seeing is thrust, maybe masses are being changed somehow, maybe it can't accelerate, just somehow reduce mass? This is why I'm doing acceleration profiles with a moving beam and static pressure readings on the same DUT and test stand. Is there a difference? I don't honestly know.


Shell

Well if the thing can produce thrust at the same N/kw as a Cesna engine, then it would seem to have clear terrestrial applications even as a thermal effect.

Reduced mass shouldn't be a downward movement.  If this thing really is playing with mass then I'm pretty sure the implications for physics are mind blowing.

Offline SeeShells

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Urm, can we establish a floor above which it becomes unlikely that a device not specifically engineered to produce thrust will be able to reach.  Seems like there should be a point, on a N/kw basis where you need some kind of propeller or rocket nozzle.  An efficiency beyond that point, and something is happening.
Anything beyond the thrust of a photon rocket or on par with a ion engine is a game changer in many many ways.

But here is the kicker, we not even sure if what we're seeing is thrust, maybe masses are being changed somehow, maybe it can't accelerate, just somehow reduce mass? This is why I'm doing acceleration profiles with a moving beam and static pressure readings on the same DUT and test stand. Is there a difference? I don't honestly know.


Shell

Well if the thing can produce thrust at the same N/kw as a Cesna engine, then it would seem to have clear terrestrial applications even as a thermal effect.

Reduced mass shouldn't be a downward movement.  If this thing really is playing with mass then I'm pretty sure the implications for physics are mind blowing.
ANY thrust or deviation from nothing happening is going to upset the apple cart SteveD.

Shell

Offline OnlyMe

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Urm, can we establish a floor above which it becomes unlikely that a device not specifically engineered to produce thrust will be able to reach.  Seems like there should be a point, on a N/kw basis where you need some kind of propeller or rocket nozzle.  An efficiency beyond that point, and something is happening.
Anything beyond the thrust of a photon rocket or on par with a ion engine is a game changer in many many ways.

But here is the kicker, we not even sure if what we're seeing is thrust, maybe masses are being changed somehow, maybe it can't accelerate, just somehow reduce mass? This is why I'm doing acceleration profiles with a moving beam and static pressure readings on the same DUT and test stand. Is there a difference? I don't honestly know.


Shell

Well if the thing can produce thrust at the same N/kw as a Cesna engine, then it would seem to have clear terrestrial applications even as a thermal effect.

Reduced mass shouldn't be a downward movement.  If this thing really is playing with mass then I'm pretty sure the implications for physics are mind blowing.
ANY thrust or deviation from nothing happening is going to upset the apple cart SteveD.

Shell

Well you stepped into this one... Should get ready to pick up apples?

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