Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1876635 times)

Offline Rodal

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I keep thinking about flat versus curved. You can get a higher Q shaping the cavity to the spherical wave shape, but peaking the Q will also open the door to more sensitivity to thermal expansion effects thereby dropping the Q in unwanted waveforms and patterns that almost are uncontrolled and sure to be disruptive. At higher powers it could be a detrimental effect as the copper frustum warpage changes from varying heat signatures in the copper.

A flat plat will give a Q oh let's say 50-90k and might offer a more forgiving environment.

Shell
I like the way you are thinking about this. 

Concerning spherical vs. flat, here are some mechanical arguments for spherical ends:

1) For the EM Drive geometries that researchers have investigated so far the spherical ends give an arc that is very shallow: the difference between the spherical arc length and the diameter of the flat end is only about 1% or 2% at most for the geometries I examined.

2) A flat end can buckle, and if it buckles it will adopt a shallow spherical shape under axial thermal loads.  A spherical end is already spherical of course:  it takes a much larger stress (a pinch force from the convex side) to make it "snap-through buckling" (because that involves higher buckling modes taking more energy).

3) In essence the geometry of an egg has been well-tested by time as being less fragile in a sense than flat ends made of thin materials.  Curved shells are better to carry loads than flat plates.  Think of an arch as in Roman arches, etc.

7) the best end for a cylindrical vessel under internal or external pressure is hemi-spherical, better than flat ends. 
« Last Edit: 07/09/2015 07:40 PM by Rodal »

Offline WarpTech

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There was some question about growth in field strength in the resonant cavity. This shouldn't be a surprise.  This is a resonant cavity, an energy storage device, with some value of Q which may be modest or very high. It doesn't matter in this instance because we are working with only 32 cycles from the start at zero energy. 32 cycles is not enough input energy to build up the stored energy in the cavity to its potential. After 32 cycles the stored energy cannot be be close to saturation. We are expecting the stored energy to reach 1000 times that value. The energy (amplitude) within the cavity is increasing due to the constant energy input.

I guess this does underline the need to look at some much longer meep runs.

We may be overlooking the significance that I've mentioned several times already. It should only thrust when the thing is charging or discharging. Not when it is in steady state. In this charging phase, we are seeing a Poynting vector doing exactly what it is expected to do. Have a strong DC offset and increasing in amplitude, both of which imply there is thrust. Once it reaches steady state, please don't make the mistake of seeing an oscillating Poynting vector and no DC offset and saying "See, there should not be any thrust!". That would be a huge mistake, IMO.
Todd

Offline Rodal

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There was some question about growth in field strength in the resonant cavity. This shouldn't be a surprise.  This is a resonant cavity, an energy storage device, with some value of Q which may be modest or very high. It doesn't matter in this instance because we are working with only 32 cycles from the start at zero energy. 32 cycles is not enough input energy to build up the stored energy in the cavity to its potential. After 32 cycles the stored energy cannot be be close to saturation. We are expecting the stored energy to reach 1000 times that value. The energy (amplitude) within the cavity is increasing due to the constant energy input.

I guess this does underline the need to look at some much longer meep runs.

We may be overlooking the significance that I've mentioned several times already. It should only thrust when the thing is charging or discharging. Not when it is in steady state. In this charging phase, we are seeing a Poynting vector doing exactly what it is expected to do. Have a strong DC offset and increasing in amplitude, both of which imply there is thrust. Once it reaches steady state, please don't make the mistake of seeing an oscillating Poynting vector and no DC offset and saying "See, there should not be any thrust!". That would be a huge mistake, IMO.
Todd

Excellent thinking!

Yes, although the analysis may not be exactly what is going on (since we have not yet arrived at a formal proof that is universally accepted) the transient response is more important to understand than the standing wave response which is easier to understand and can be obtained from exact solutions.

Offline WarpTech

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The paradox with propellant driven space craft was explained too, by Dr. White. It occurs anytime "constant acceleration" is assumed, without taking into account the variables in the av(t) expression I posted. In the case of the EM drive where there is no exhaust, dm/dt is replaced by the change in potential energy from the small end, to the big end, per unit time, /c2.

And BTW, if the EM drive were to store every bit of energy put into it, with a high power source it would have to explode eventually. The energy either needs to escape, generate heat or move the thing in order to dissipate. Or else the source input will eventually become saturated until nothing more will go in.
Todd
Each time I try to stay on topic with this breakeven business, which you say I have "wrong", you throw another spanner in the works. Let's try and focus here. I want to understand what's "wrong" as you see it. So far, you're not making sense to me. If you do want to make sense to me, and convince me that I'm "wrong", you're going to have to take my derivation and show, line by line, the "right" substitution.

Over to you.

Here is how it's done, starting from your format to mine. The difference in potential energy is from the initial energy state at the small end, to the final energy state at the big end.
Todd

Thanks Todd. That gets me a lot closer to an understanding of your radically different approach. I have gone through your derivation and algebraically I have no issues with it. But I can't say I'm there yet, being ever mystified by this darned dm/dt term. Some comments:

1. Writing 'u' for the phase velocity, you get
k = u/c2 Newton/Watt = 1/c when u=c,
or in other words a pure photon rocket. But experimental evidence suggests a much higher value for k, and so if your formula is correct, it is predicting a superluminal phase velocity.
Is that your intent? Do you think that this observation is important?

2. When you derive the breakeven velocity for the condition dEin = dEout, this is tantamount to the power breakeven condition. In this case, I get vp = 1/k, and so do you. So at least on this point we are in accord.

3. Since, then, you actually derive a value for k (which I do not), you can specify the value
vp  = c2/u.
Since you're implying u >> c, it's unclear what the actual value of vp  might be, but it certainly is << c if u >> c.
e.g. if we write u = b*c (b >> 1), then
vp  = c/b << c

1. For a phase velocity >> c, the group velocity is << c. So F * vg will have a lot more Force with a lot less Power than a photon rocket. So yes, u >> c is very important.

The important thing is, Pin = Pout. The vehicle will accelerate dependent on the available input power until relativistic effects start to change the parameters of the problem. It never goes over-unity. That is simply a mis-inerpretation of what "break-even" means.
Todd

Offline Flyby

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If I get you correctly, you'd like to have a top view, cut through the middle of the waveguide?
It all depends on whether that waveguide is rectangular or cylindrical...

If it is cylindrical, i can generate such drawing, if it is square or rectangular, i'll need the width of it...
In the mean time, even I believe the drawing is most likely not accurate, I assumed it was and made the measurements proportional to the full height, that being 100%....
Thank you so much for dedicating your valuable time to make that drawing.

Much appreciated.

Yes I was looking for a guesstimate of what it would look like from a view at the plane at 90 degrees, assuming that the cavity is conical with a circular cross section perpendicular to the axis of axisymmetry.

huh...
I think you're forgetting that English is only my 3rd language and that i never had any math classes in English...
 I've been rereading your phrasing 4 times and still do not understand what you've been saying...sigh... :-[

To put it simple...If the provided drawing is a frontal view cut, do you want :
-left view cut
-right view cut (view towards the waveguide)
-top view cut?



btw, if you and/or aero (or any meep virtuoso) provide new images, could it be possible to use black backgrounds and bright colors, please?

It would allow me to extract an alpha channel from the image RGB values and render a pseudo-3D volumetric of the frustum cavity.

The sample below has only 1 image and took some serious color altering (hence not so accurate) to get an opacity channel from it.

For the final images/animation I can gradually interpolate (percentage mixing according angle) between the different images in the XY and the YZ plane to get a more accurate representation.

Offline SeeShells

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I keep thinking about flat versus curved. You can get a higher Q shaping the cavity to the spherical wave shape, but peaking the Q will also open the door to more sensitivity to thermal expansion effects thereby dropping the Q in unwanted waveforms and patterns that almost are uncontrolled and sure to be disruptive. At higher powers it could be a detrimental effect as the copper frustum warpage changes from varying heat signatures in the copper.

A flat plat will give a Q oh let's say 50-90k and might offer a more forgiving environment.

Shell
I like the way you are thinking about this. 

Concerning spherical vs. flat, here are some mechanical arguments for spherical ends:

1) For the EM Drive geometries that researchers have investigated so far the spherical ends give an arc that is very shallow: the difference between the spherical arc length and the diameter of the flat end is only about 1% or 2% at most for the geometries I examined.

2) A flat end can buckle, and if it buckles it will adopt a shallow spherical shape under axial thermal loads.  A spherical end is already spherical of course:  it takes a much larger axial stress to make it "snap-through buckling" (because that involves higher buckling modes taking more energy).

3) In essence the geometry of an egg has been well-tested by time as being less fragile in a sense than flat ends made of thin materials.  Curved shells are better to carry loads than flat plates.  Think of an arch as in Roman arches, etc.

7) the best end for a cylindrical vessel under internal or external pressure is hemi-spherical, better than flat ends.
It's not the end plates that concern me as much as the sidewalls, don't forget that copper conducts heat quite well. the expansion in the sidewalls will increase the overall length making the cavity resonate a little lower (we see this). The endplates on the other hand if made flat will not tend to buckle in and out of the plane of the cavity but expand outwards towards the sidewalls.

I'm not going to bolt or silver solder the endplate in but secure it in place with a shape deforming conductive gasket that will allow the plate to thermally expand.  A flatter plate allows this, but I might consider a shallow concave plate after looking some more.

Nasty paint pic following. lol

Shell

Offline Rodal

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I would appreciate a 1) top view cut and/or 2) left view cut to have an understanding of the waveguide dimension in the transverse direction.  But it looks like Yang does not provide the waveguide transverse dimension information, so it is not really possible unless someone like TheTraveller has some intuition (or inside information) as to what Yang did.  Do you agree? (we can guesstimate the cone transverse dimensions but not  the waveguide's for which we have no information)

Offline deltaMass

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The paradox with propellant driven space craft was explained too, by Dr. White. It occurs anytime "constant acceleration" is assumed, without taking into account the variables in the av(t) expression I posted. In the case of the EM drive where there is no exhaust, dm/dt is replaced by the change in potential energy from the small end, to the big end, per unit time, /c2.

And BTW, if the EM drive were to store every bit of energy put into it, with a high power source it would have to explode eventually. The energy either needs to escape, generate heat or move the thing in order to dissipate. Or else the source input will eventually become saturated until nothing more will go in.
Todd
Each time I try to stay on topic with this breakeven business, which you say I have "wrong", you throw another spanner in the works. Let's try and focus here. I want to understand what's "wrong" as you see it. So far, you're not making sense to me. If you do want to make sense to me, and convince me that I'm "wrong", you're going to have to take my derivation and show, line by line, the "right" substitution.

Over to you.

Here is how it's done, starting from your format to mine. The difference in potential energy is from the initial energy state at the small end, to the final energy state at the big end.
Todd

Thanks Todd. That gets me a lot closer to an understanding of your radically different approach. I have gone through your derivation and algebraically I have no issues with it. But I can't say I'm there yet, being ever mystified by this darned dm/dt term. Some comments:

1. Writing 'u' for the phase velocity, you get
k = u/c2 Newton/Watt = 1/c when u=c,
or in other words a pure photon rocket. But experimental evidence suggests a much higher value for k, and so if your formula is correct, it is predicting a superluminal phase velocity.
Is that your intent? Do you think that this observation is important?

2. When you derive the breakeven velocity for the condition dEin = dEout, this is tantamount to the power breakeven condition. In this case, I get vp = 1/k, and so do you. So at least on this point we are in accord.

3. Since, then, you actually derive a value for k (which I do not), you can specify the value
vp  = c2/u.
Since you're implying u >> c, it's unclear what the actual value of vp  might be, but it certainly is << c if u >> c.
e.g. if we write u = b*c (b >> 1), then
vp  = c/b << c

1. For a phase velocity >> c, the group velocity is << c. So F * vg will have a lot more Force with a lot less Power than a photon rocket. So yes, u >> c is very important.

The important thing is, Pin = Pout. The vehicle will accelerate dependent on the available input power until relativistic effects start to change the parameters of the problem. It never goes over-unity. That is simply a mis-inerpretation of what "break-even" means.
Todd
I believe, based on what I wrote above, that you have not made the case for "no power breakeven until v = c". Indeed, we agree that this breakeven speed is substantially less than c if we take your formula for k to be correct and we take the phase velocity to be superluminal. The question which intrigues me is what the value of 'b' might be (u = b*c). Do you have a handle on quantifying this phase velocity value?




Offline BL

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Re rfmwguy post #3776


“I hope all supporters and detractors drop you a couple of bucks for giving it a go. Posting is cheap...building is not.”

Just want to let all concerned, especially SeeShells and all the rest who are ‘putting their money where their hopes are’, that in spite of my incessant whining (opinion—would be happy to be proven wrong) about the horrors of oven magnetrons as frustum drivers I am VERY firmly in the supporter camp.  As I said before, if any of the DIY’ers are in the Northern VA/DC/Suburban MD area there is at least some possibility that I may be able to get them access to top of the line microwave test equipment, including broadband amplifiers (not magnetrons) in the +40/+50 dBm  range. 

Offline Flyby

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I would appreciate a 1) top view cut and/or 2) left view cut to have an understanding of the waveguide dimension in the transverse direction.  But it looks like Yang does not provide the waveguide transverse dimension information, so it is not really possible unless someone like TheTraveller has some intuition (or inside information) as to what Yang did.  Do you agree? (we can guesstimate the cone transverse dimensions but not  the waveguide's for which we have no information)

Does it make sense that the waveguide is a cylinder?
If that is plausible, then it is fairly straightforward to make a cut view.

Even if the waveguide has a square cross section, it is still possible...

However, if it is rectangular, then we need to find the depth dimension, either from another drawing or from the Chinese text, to complete such a drawing.

As the current drawing does not show a typical vertical axis-cut line (according international drawing conventions), we can relative safely assume that the waveguide enters the frustum in the center.
« Last Edit: 07/09/2015 08:05 PM by Flyby »

Offline rfmwguy

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Martin Tajmar - AAIA presentation this month - his possible presentation notes - FYI drbagelbites:

http://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_maschinenwesen/ilr/rfs/forschung/folder.2007-08-21.5231434330/ag_raumfahrtantriebe/Biefeld-Brown%20Effect%20AIAA%20Journal%20Revised.pdf

Worth reading as his 2004 paper deals with The Biefeld-Brown Effect: Misinterpretation of Corona Wind
Phenomena

IOW,

"1. The separation of the plates of the capacitor: the closer the plates, the greater the effect.
2. The dielectric strength of the material between the electrodes: the higher the strength, the greater the effect.
3. The area of the conductors: the greater the area, the greater effect.
4. The voltage difference between the plates: the greater the voltage, the greater effect.
5. The mass of the dielectric material; the greater the mass, the greater the effect."

Shawyers frustum appeared to have an insulated larger frustum plate, maybe both. In effect, these plates might have been charged electrodes creating "corona wind". Regardless, might be worth reading before attending his presentation.
« Last Edit: 07/09/2015 08:27 PM by rfmwguy »

Offline X_RaY

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So the real cavity has spherical or plane taps?
Thanks.  Excellent analysis.  NASA COMSOL FEA found some weird modes also that were a mixture, using plane ends.  Most of the researchers have used FLAT ends on their experiments with truncated cones.

All NASA experiments have had flat ends.  Some of Shawyer''s have had flat ends, from what I recall, according to TheTraveller, Shawyer's FlightThruster has spherical ends.

Prof. Yang's have flat ends.

Iulian Berca has flat ends.

Baby EM Drive has flat ends.

The exact solution I have been using uses spherical ends,  when approximating a flat end natural frequency I calculate the geometry that has spherical ends halfway between the circumscribed and the inscribed circles (that came close to NASA's COMSOL FEA analysis of all the modes between 0.8 and 2.6 MHz for.

Meep models have been using flat ends on conical cavities.
I keep thinking about flat versus curved. You can get a higher Q shaping the cavity to the spherical wave shape, but peaking the Q will also open the door to more sensitivity to thermal expansion effects thereby dropping the Q in unwanted waveforms and patterns that almost are uncontrolled and sure to be disruptive. At higher powers it could be a detrimental effect as the copper frustum warpage changes from varying heat signatures in the copper.

A flat plat will give a Q oh let's say 50-90k and might offer a more forgiving environment.

Shell

Hi :) Got a stupid question: Leads hyperbolic end plates to a higher Q than a spherical or a flat one? And a curved sidewall to a higher Q than a straight one?
« Last Edit: 07/09/2015 09:02 PM by X_RaY »

Offline flux_capacitor

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Shawyers frustum appeared to have an insulated larger frustum plate, maybe both. In effect, these plates might have been charged capacitors exhibiting the "corona wind".

Interesting. This raises two questions:
- Does the process of resonating microwaves inside a cavity is naturally known to produce an electric potential difference between two conductive plates (both isolated from the frustum and each other by a dielectric gasket) ?
- If so, for EmDrive designs with plates electrically isolated from the frustum, could we just connect the two plates together with a ground wire (outside of the cavity) to prevent any voltage and thus any ion wind around the cavity?

Offline Ricvil

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There was some question about growth in field strength in the resonant cavity. This shouldn't be a surprise.  This is a resonant cavity, an energy storage device, with some value of Q which may be modest or very high. It doesn't matter in this instance because we are working with only 32 cycles from the start at zero energy. 32 cycles is not enough input energy to build up the stored energy in the cavity to its potential. After 32 cycles the stored energy cannot be be close to saturation. We are expecting the stored energy to reach 1000 times that value. The energy (amplitude) within the cavity is increasing due to the constant energy input.

I guess this does underline the need to look at some much longer meep runs.


We may be overlooking the significance that I've mentioned several times already. It should only thrust when the thing is charging or discharging. Not when it is in steady state. In this charging phase, we are seeing a Poynting vector doing exactly what it is expected to do. Have a strong DC offset and increasing in amplitude, both of which imply there is thrust. Once it reaches steady state, please don't make the mistake of seeing an oscillating Poynting vector and no DC offset and saying "See, there should not be any thrust!". That would be a huge mistake, IMO.
Todd

Excellent thinking!

Yes, although the analysis may not be exactly what is going on (since we have not yet arrived at a formal proof that is universally accepted) the transient response is more important to understand than the standing wave response which is easier to understand and can be obtained from exact solutions.

Just another point of attention.

The resulting electromagnetic force, with the fields confined inside cavity, calculated  from the poyting vector, is F=-(1/c^2).d(integral_vol(S))/dt, where S=ExH
So a constant, at principle, make no difference to resulting force on whole cavity.
Of course, the graph is about one spacial point, and is a extrapolation of few temporal samples,  but the resulting force depends of all volume and the distribuition of the fields.
If one argument about a net force resulting of vibrations, changing the total volume/format of the cavity, will have to demonstrate it, and it will be very hard because the deformations are very tiny, cyclical and field dependent, resulting a zero net force at principle.
« Last Edit: 07/09/2015 08:37 PM by Ricvil »

Offline zellerium

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I would appreciate a 1) top view cut and/or 2) left view cut to have an understanding of the waveguide dimension in the transverse direction.  But it looks like Yang does not provide the waveguide transverse dimension information, so it is not really possible unless someone like TheTraveller has some intuition (or inside information) as to what Yang did.  Do you agree? (we can guesstimate the cone transverse dimensions but not  the waveguide's for which we have no information)

Does it make sense that the waveguide is a cylinder?
If that is plausible, then it is fairly straightforward to make a cut view.

Even if the waveguide has a square cross section, it is still possible...

However, if it is rectangular, then we need to find the depth dimension, either from another drawing or from the Chinese text, to complete such a drawing.

As the current drawing does not show a typical vertical axis-cut line (according international drawing conventions), we can relative safely assume that the waveguide enters the frustum in the center.

Judging by the tuning mechanisms used, looks like they used a rectangular waveguide.
In my opinion, I don't think they would go through the effort of drawing their picture to scale.
« Last Edit: 07/09/2015 08:51 PM by zellerium »

Offline rfmwguy

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Shawyers frustum appeared to have an insulated larger frustum plate, maybe both. In effect, these plates might have been charged capacitors exhibiting the "corona wind".

Interesting. This raises two questions:
- Does the process of resonating microwaves inside a cavity is naturally known to produce an electric potential difference between two conductive plates (both isolated from the frustum and each other by a dielectric gasket) ?
- If so, for EmDrive designs with plates electrically isolated from the frustum, could we just connect the two plates together with a ground wire (outside of the cavity) to prevent any voltage and thus any ion wind around the cavity?
So, I've been SLOWLY working on my own theory at the 40K ft level. Assymetrical (end) plates, insulated from one another are capacitive plates with a dielectric (air) medium. An even better capacitor would be created by putting in a dielectric puck, HDFE, which is what EW did. But don't think thats why they did it.

RF radiation striking the end plates impart Ev and a potential builds up ONLY if the plates are insulated from one another. The EW frustum does not appear to have insulated end-plates and I would not call it a capacitor, nor do I think it is exhibiting the corona/ion effect. Outgassing? Maybe.

Regardless, I've set my design up to be able to insulate the end plates, so I can test the capacitor/corona theory. My first test will be with uninsulated end plates, test #2 will be with insulated end plates...as it stands now.

Offline WarpTech

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1. For a phase velocity >> c, the group velocity is << c. So F * vg will have a lot more Force with a lot less Power than a photon rocket. So yes, u >> c is very important.

The important thing is, Pin = Pout. The vehicle will accelerate dependent on the available input power until relativistic effects start to change the parameters of the problem. It never goes over-unity. That is simply a mis-inerpretation of what "break-even" means.
Todd
I believe, based on what I wrote above, that you have not made the case for "no power breakeven until v = c". Indeed, we agree that this breakeven speed is substantially less than c if we take your formula for k to be correct and we take the phase velocity to be superluminal. The question which intrigues me is what the value of 'b' might be (u = b*c). Do you have a handle on quantifying this phase velocity value?

What can I say, except today I have a better handle on it than I did yesterday, or the day before... I'm learning too! Now, I understand that "break even" means that Pin = Pout, or 100% conversion efficiency. It doesn't mean anything more than that.

The phase velocity depends on the dimensions of the frustum and the frequency driving it. There will be more details on that in my forthcoming paper.
Todd

Offline DrBagelBites

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Martin Tajmar - AAIA presentation this month - his possible presentation notes - FYI drbagelbites:

http://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_maschinenwesen/ilr/rfs/forschung/folder.2007-08-21.5231434330/ag_raumfahrtantriebe/Biefeld-Brown%20Effect%20AIAA%20Journal%20Revised.pdf

Worth reading as his 2004 paper deals with The Biefeld-Brown Effect: Misinterpretation of Corona Wind
Phenomena

IOW,

"1. The separation of the plates of the capacitor: the closer the plates, the greater the effect.
2. The dielectric strength of the material between the electrodes: the higher the strength, the greater the effect.
3. The area of the conductors: the greater the area, the greater effect.
4. The voltage difference between the plates: the greater the voltage, the greater effect.
5. The mass of the dielectric material; the greater the mass, the greater the effect."

Shawyers frustum appeared to have an insulated larger frustum plate, maybe both. In effect, these plates might have been charged electrodes creating "corona wind". Regardless, might be worth reading before attending his presentation.

I'll be sure to take a look prior to the presentation. Thanks for the info

Offline demofsky

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Martin Tajmar - AAIA presentation this month - his possible presentation notes - FYI drbagelbites:

http://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_maschinenwesen/ilr/rfs/forschung/folder.2007-08-21.5231434330/ag_raumfahrtantriebe/Biefeld-Brown%20Effect%20AIAA%20Journal%20Revised.pdf

Worth reading as his 2004 paper deals with The Biefeld-Brown Effect: Misinterpretation of Corona Wind
Phenomena

IOW,

"1. The separation of the plates of the capacitor: the closer the plates, the greater the effect.
2. The dielectric strength of the material between the electrodes: the higher the strength, the greater the effect.
3. The area of the conductors: the greater the area, the greater effect.
4. The voltage difference between the plates: the greater the voltage, the greater effect.
5. The mass of the dielectric material; the greater the mass, the greater the effect."

Shawyers frustum appeared to have an insulated larger frustum plate, maybe both. In effect, these plates might have been charged electrodes creating "corona wind". Regardless, might be worth reading before attending his presentation.

Thanks for the link to this paper.  One thing that jumped out at me was the following from the bottom of page 4:
Quote
Two decades later, Talley studied Brown’s electrode configurations in vacuum chambers up to 10-6 Torr in great detail19,20. He found no thrust in the case of a static DC potential applied to the electrodes. However he noticed an anomalous force during electrical breakdowns when a current was flowing.

Hello duty cycle!  And in a vacuum!!

A few things from the my recollection of the Townsend Brown legends stood out for me while reading these discussions:

  -  He got started on his investigations when he noticed that an oscilloscope he was working with jumped noticeably when he turned off the power.  Hello fustrum.  Hello duty cycle.  Note that this was in the 1920's so the scopes of that time used high voltages to drive them.

  -  A lot of his work involved using solid dielectrics, allegedly, and he got good results with this. (So much for coronal wind.) Most interestingly was his claim that his dielectric levitation effect was a quantized one and not continuous!!  That is, the capacitors moved from one discrete level to another rather than smoothly rising.

Edit: tweaking clarity.
« Last Edit: 07/09/2015 10:01 PM by demofsky »

Offline rfmwguy

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Martin Tajmar - AAIA presentation this month - his possible presentation notes - FYI drbagelbites:

http://tu-dresden.de/die_tu_dresden/fakultaeten/fakultaet_maschinenwesen/ilr/rfs/forschung/folder.2007-08-21.5231434330/ag_raumfahrtantriebe/Biefeld-Brown%20Effect%20AIAA%20Journal%20Revised.pdf

Worth reading as his 2004 paper deals with The Biefeld-Brown Effect: Misinterpretation of Corona Wind
Phenomena

IOW,

"1. The separation of the plates of the capacitor: the closer the plates, the greater the effect.
2. The dielectric strength of the material between the electrodes: the higher the strength, the greater the effect.
3. The area of the conductors: the greater the area, the greater effect.
4. The voltage difference between the plates: the greater the voltage, the greater effect.
5. The mass of the dielectric material; the greater the mass, the greater the effect."

Shawyers frustum appeared to have an insulated larger frustum plate, maybe both. In effect, these plates might have been charged electrodes creating "corona wind". Regardless, might be worth reading before attending his presentation.

Thanks for the link to this paper.  One thing that jumped out at me was the following from the bottom of page 4:
Quote
Two decades later, Talley studied Brown’s electrode configurations in vacuum chambers up to 10-6 Torr in great detail19,20. He found no thrust in the case of a static DC potential applied to the electrodes. However he noticed an anomalous force during electrical breakdowns when a current was flowing.

Hello duty cycle!  And in a vacuum!!

A few things from the my recollection of the Townsend Brown legends stood out for me while reading these discussions:

  -  He got started on his investigations when he noticed that an oscilloscope he was working with jumped noticeably when he turned off the power.  Hello fustrum.  Hello duty cycle.  Note that this was in the 1920's so the scopes of that time used high voltages to drive them.

  -  A lot of his work involved using solid dielectrics, allegedly, and he got good results with this. (So much for coronal wind.) Most interestingly was his claim that his dielectric levitation effect was a quantized one and not continuous!!  That is, the capacitors moved from one discrete level to another rather than smoothly rising.

Edit: tweaking clarity.
Yep, with a lot of eyes on these types of papers, I'm convinced things will become clear in short order...hopefully not another 95 years ;^)

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