Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1872032 times)

Offline Rodal

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It is deceptive to use the efficiency parameter (N/kW) when you see on Yang's graph's that when you increase power you end up with a way lower efficiency (720mN/2.5kW).

What this shows that the thermal impact has a far bigger impact then you assume and that with and increased Q you're massing up gigantic power intensities in the resonance patterns.

With needed Q's in the order of 10^10 i really doubt if cooled nitrogen will be able to keep the frustum walls cooled...
IIRC, Shawyer talked about 17MW of stored energy in the cavity, by only using "700W to 1kW-ish" microwave generators and with a Q of barely 50k....

Agreed, i'm no specialist in the matter, but it looks to me a near impossible engineering challenge, to pack all that in a minimal configuration, with a low enough weight to power ratio, so it can fly...

IF the EMdrive ever turns out to be something (no hard evidence till today), it will be usable for orbit positioning, interplanetary travel and maybe interstellar probes...but terrestrial liftoff vehicles ? nah...

The thermal degeneration on the Q is only going to grow the more power you put into it...at certain point, even supercooled liquids wont be enough to handle the thermal issues....

Just adding on to this, does anyone have any idea (@rfmqguy in particular) what the highest Q ever obtained by an electromagnetic resonator (whether a cavity or circuit) is?  Ie. in the actual physical world, what is the best Q ever obtained?

10^10 to 10^11 for superconducting single cell cavities

in the chart below Qo is the Intrinsic Q
« Last Edit: 07/31/2015 02:43 PM by Rodal »

Offline wallofwolfstreet

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Awesome, I guess we know that the high Q's needed have at least been obtained before

Offline deltaMass

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@TT:
There's a video of Shawyer's device slowly rotating (you've posted it many times; you know the one). There's also a graph of power and thrust over time (you've also posted many times).
Are you sure that they go together?

Reason I ask is that the speed looks about constant - there is little discernable acceleration at all.

Offline flux_capacitor

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I asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed internal radii instead of diameters.

He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.

For now, the updated paper is online on the UD-Dresden website.

In the updated paper the height is still confirmed to be 68.6 mm:
Quote from: Martin Tajmar
Our final tapered cavity design had an internal top radius of 38.5 mm, a bottom radius of 54.1 mm and a height of 68.6 mm

So:
- internal big diameter = 0.1082 m
- internal small diameter = 0.077 m
- height = 0.00686 m

To @Rodal, @TheTraveller and others: can you try to find resonances and modes with your COMSOL and spreadsheets programs with those dimensions?
« Last Edit: 07/31/2015 03:02 PM by flux_capacitor »

Offline rfmwguy

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I tried this yesterday, but failed miserably...here is the google+ page where you can see all my videos:

https://plus.google.com/102151053813184986030/videos

When ?, what is the latest estimated date for the first experiment measuring thrust?

Where is going to be the RF feed located during the first experiment? (big base or small base?)
Patience grasshopper... ;)

Power insertion is 1/4 wave from side, longitudinally aligned with axis on small base.

More power testing tonight or tomorrow. I will do this repeatedly until I'm convinced magnetron match is good and there are no signs of degradation or arcing in the frustum. Goal is 90 deg C magnetron stability. Yes, I will attempt 5 minutes at full power.

Once I am satisfied with this config, its on the fulcrum. First with wired power leads. Mainly because Galinstan is so expensive and I'll need 3 small cups of it. Perhaps if I begged the interwebs, I could get donations and make it sooner ;)

Long story short, I estimate about 10 days for first thrust test, similar to Julian's without wet contacts.

Offline Rodal

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I asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed radii instead of diameters.

He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.

For now, the updated paper is online on the UD-Dresden website.

In the updated paper the height is still confirmed to be 68.6 mm.
That height (68.6mm) does not result in resonance at 2.44 GHz.  Did you discuss the height with him as well?

Offline Rodal

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Awesome, I guess we know that the high Q's needed have at least been obtained before

Electropolishing required to eliminate multipaction:

the reason for electropolishing to eliminate surface defects and work well with high Q has nothing to do with the wavelength, etc., of course.  The reason for electropolishing is to eliminate multipaction problem

Multipaction is the problem associated with resonant cavities that the NASA guy had mentioned as the possible source of the anomalous thrust of the EM Drive. 

Multipaction is a phenomenon in which an electromagnetic field causes a free electron to impact a surface, resulting in the surface emitting one or more secondary electrons. If the surface geometry and electromagnetic fields are appropriately arranged, the secondary electrons can then be accelerated and again impact a surface in the bounding geometry. If the net number of secondary electrons participating in multipactor is non-decreasing, then the process can repeat indefinitely.

Norbert Holtkamp, ORNL - SNS

Seminar at MIT

http://filburt.mit.edu/cast/seminars/20050615holtkamp.pdf
« Last Edit: 07/31/2015 03:30 PM by Rodal »

Offline flux_capacitor

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I asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed radii instead of diameters.

He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.

For now, the updated paper is online on the UD-Dresden website.

In the updated paper the height is still confirmed to be 68.6 mm.
That height (68.6mm) does not result in resonance at 2.44 GHz.  Did you discuss the height with him as well?

I know. I will ask him in return if this value of 68.6 mm is the external height, or the internal maximal height, and what is exactly the final internal height at resonance after the tuning screw was fixed.

Offline WarpTech

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...
http://forum.nasaspaceflight.com/index.php?topic=37642.msg1404523#msg1404523
Why is vacuum Energie ^120 times to big? ???
Because of the mathematical singularities associated with Quantum Mechanics, and the inability up to now to come up with a unified theory of Quantum Gravity.  So, I take the ^120 problem as a symptom of the fact that we don't yet have a satisfactory theory of Quantum Gravity.  I would rather rely on the astronomical measurements pointing towards the value of the cosmological constant than relying on Quantum Mechanics calculations for the vacuum energy.  I would not rely on Quantum Mechanics calculations of the vacuum energy until we have a theory of Quantum Gravity.  We were able to explain inflation without a theory of Quantum Gravity.

I have a working model of QG that works very well, matches GR and QED and explains inflation. It's all in my warp drive paper, which I am STILL waiting on JBIS to review, since January. The 120 orders of magnitude problem is a problem with our understanding of how the ZPF works. It doesn't gravitate, it is the field inside protons that inflates them to the size they are in our local spacetime. All mater is in equilibrium with this field, that is why it doesn't gravitate. So that problem is a non-issue in my QG. It is only in the Classical sense that matter is immutable where it becomes an issue.
Todd

Offline Rodal

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I asked Martin Tajmar directly by email about cavity dimensions that would be off by a factor 2, and he replied confirming the numbers were indeed radii instead of diameters.

He added he already uploaded a revised manuscript altogether with some other typo corrections and some additional clarifications at the AIAA website, but revisions from the conference will appear only after 21st of August.

For now, the updated paper is online on the UD-Dresden website.

In the updated paper the height is still confirmed to be 68.6 mm.
That height (68.6mm) does not result in resonance at 2.44 GHz.  Did you discuss the height with him as well?

I know. I will ask him in return if this value of 68.6 mm is the external height, or the internal maximal height, and what is exactly the final internal height at resonance after the tuning screw was fixed.

Quote
To @Rodal, @TheTraveller and others: can you try to find resonances and modes with your COMSOL and spreadsheets programs with those dimensions? 

Already answered in my previous posts showing the fields and the resonance results.  A height close to the big diameter 0.10 m  is needed to resonate at 2.44 GHz.  Lower heights means higher resonant frequency

Besides, as mentioned multiple times by WarpTech and TheTraveller, the waveguide canNOT attach to the cavity with the 68.6 mm height !

Wish that when the wrong dimensions were pointed out to Tajmar he would have asked people at this lab to do a thorough job at double checking ALL numbers and not just the radii ...

Sigh ...
« Last Edit: 07/31/2015 03:21 PM by Rodal »

Offline rfmwguy

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It is deceptive to use the efficiency parameter (N/kW) when you see on Yang's graph's that when you increase power you end up with a way lower efficiency (720mN/2.5kW).

What this shows that the thermal impact has a far bigger impact then you assume and that with and increased Q you're massing up gigantic power intensities in the resonance patterns.

With needed Q's in the order of 10^10 i really doubt if cooled nitrogen will be able to keep the frustum walls cooled...
IIRC, Shawyer talked about 17MW of stored energy in the cavity, by only using "700W to 1kW-ish" microwave generators and with a Q of barely 50k....

Agreed, i'm no specialist in the matter, but it looks to me a near impossible engineering challenge, to pack all that in a minimal configuration, with a low enough weight to power ratio, so it can fly...

IF the EMdrive ever turns out to be something (no hard evidence till today), it will be usable for orbit positioning, interplanetary travel and maybe interstellar probes...but terrestrial liftoff vehicles ? nah...

The thermal degeneration on the Q is only going to grow the more power you put into it...at certain point, even supercooled liquids wont be enough to handle the thermal issues....

Just adding on to this, does anyone have any idea (@rfmqguy in particular) what the highest Q ever obtained by an electromagnetic resonator (whether a cavity or circuit) is?  Ie. in the actual physical world, what is the best Q ever obtained?
Good question wolfy, air cavities can exceed 10,000 with silver and gold plating and tight tolerances. But this is measuring Q in the classic center resonance/3dB bandwidth and NOT return loss; i.e. forward power. IOW a 2 port measurement.

These frustums are being tested with a single port, like an antenna, and they are calculating 3dB below either zero insertion, relative 3dB (to insertion loss) or in the case of China, 3dB above center return loss notch (that of course gives ridiculous Q).

So, guess I'll stick with around 10K in a classic 2 port configuration. All else is a foreign language to my way of testing.

Offline deltaMass

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So TT is deluding himself when he quotes 6-figure Q values from Yang because they are unrealistic (and wrong).

Offline rfmwguy

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For conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo.
The balancing force to gravity is labeled dark matter to explain the imbalance of forces.

I'm not sure how that follows.  Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive?  Dark matter behaves just like regular matter gravitationally.   

What imbalance of forces are you referring to specifically here?  There is no imbalance of forces in gravity from a Newton's 3rd law perspective.
Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.

Offline rfmwguy

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So TT is deluding himself when he quotes 6-figure Q values from Yang because they are unrealistic (and wrong).
I would think so. Superconductivity can jack up Qs for sure, but 100K Qs, measured in the classic sense, are...uhhh...posturing if you want my honest opinion.

Think of it as horsepower in the cavity world. The bigger the better, right? Over the top pronouncements get attention. When anyone claims super high Qs, its all relative to they test methodology they are using in the real world.

Way to solve the problem? Have them take it to: http://www.bsigroup.com or similar authority. I visitem them with a CE product test in a previous life. These guys can certify RF and Microwave performance to a T.

Offline deltaMass

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For conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo.
The balancing force to gravity is labeled dark matter to explain the imbalance of forces.

I'm not sure how that follows.  Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive?  Dark matter behaves just like regular matter gravitationally.   

What imbalance of forces are you referring to specifically here?  There is no imbalance of forces in gravity from a Newton's 3rd law perspective.
Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.
There is some indication of balance that the mainstream currently espouses - the inflaton and dark energy. Both act in an anti-gravitic sort of way. But as you probably know, the inflaton ran out of gas very quickly, and dark energy is yet to truly come into its own. So yes, gravity wins for now.
« Last Edit: 07/31/2015 03:57 PM by deltaMass »

Offline WarpTech

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For conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo.
The balancing force to gravity is labeled dark matter to explain the imbalance of forces.

I'm not sure how that follows.  Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive?  Dark matter behaves just like regular matter gravitationally.   

What imbalance of forces are you referring to specifically here?  There is no imbalance of forces in gravity from a Newton's 3rd law perspective.
Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.

Haven't you heard of Exotic Matter? It represents repulsive gravity and causes inflation. The ZPF is the driving force, setting the scale of protons and sub-atomic particles which are in equilibrium with it. Where the ZPF power is decreasing, we have gravity and gravitational length contraction and time dilation as matter deflates. Where the ZPF is increasing (think, going up-hill) the opposite is true. The ZPF is gaining power and matter is inflated in the process of lifting it. (The opposite of length contraction and time dilation.)

Exotic Matter, is simply normal matter immersed in a more powerful ZPF. The ZPF increases the energy stored but it also inflates the volume of that matter, such that the equilibrium energy density is lower than it would be in a less powerful ZPF, or in a gravity well. It is the ZPF that is responsible for gravity, it doesn't gravitate, it inflates.
Todd

Offline SeeShells

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Dr. Rodal,

I'm reviewing all my collected data this morning sorting and categorizing. I can't locate the data sets for the cavity dimensions on the Rodal-complete ez data set we ran on June 23?

https://drive.google.com/folderview?id=0B1XizxEfB23tfjVmb1RiZXpaajd6WGpGQmpSWDkxRlV3cG10TEJmWVVEbTd2U0t4MC1aa1E&usp=sharing

Thanks,
Shell

Offline rfmwguy

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For conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo.
The balancing force to gravity is labeled dark matter to explain the imbalance of forces.

I'm not sure how that follows.  Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive?  Dark matter behaves just like regular matter gravitationally.   

What imbalance of forces are you referring to specifically here?  There is no imbalance of forces in gravity from a Newton's 3rd law perspective.
Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.
There is some indication of balance that the mainstream currently espouses - the inflaton and dark energy. Both act in an anti-gravitic sort of way. But as you probably know, the inflaton ran out of gas very quickly, and dark energy is yet to truly come into its own. So yes, gravity wins for now.
Yep, this conundrum has to be resolved...whats wrong with these scientist-type guys? C'mon lets get-er-done!  8)

Offline rfmwguy

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For conservation of E & M folks, Dark Matter disappearing from theory is like saying Newton was a fraud, imo.
The balancing force to gravity is labeled dark matter to explain the imbalance of forces.

I'm not sure how that follows.  Maybe you meant dark energy there, because it is "repulsive" while familiar mass-energy is attractive?  Dark matter behaves just like regular matter gravitationally.   

What imbalance of forces are you referring to specifically here?  There is no imbalance of forces in gravity from a Newton's 3rd law perspective.
Sloppily saying gravity is the only know force without a repulsive condition, thus an imbalance in the big scheme of things.

Haven't you heard of Exotic Matter? It represents repulsive gravity and causes inflation. The ZPF is the driving force, setting the scale of protons and sub-atomic particles which are in equilibrium with it. Where the ZPF power is decreasing, we have gravity and gravitational length contraction and time dilation as matter deflates. Where the ZPF is increasing (think, going up-hill) the opposite is true. The ZPF is gaining power and matter is inflated in the process of lifting it. (The opposite of length contraction and time dilation.)

Exotic Matter, is simply normal matter immersed in a more powerful ZPF. The ZPF increases the energy stored but it also inflates the volume of that matter, such that the equilibrium energy density is lower than it would be in a less powerful ZPF, or in a gravity well. It is the ZPF that is responsible for gravity, it doesn't gravitate, it inflates.
Todd
Yep, exotic/dark matter and other theories. When it is eventually proven, so leads the way to GUT...at least thats my guess.

Offline flux_capacitor

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Exotic Matter, is simply normal matter immersed in a more powerful ZPF. The ZPF increases the energy stored but it also inflates the volume of that matter, such that the equilibrium energy density is lower than it would be in a less powerful ZPF, or in a gravity well. It is the ZPF that is responsible for gravity, it doesn't gravitate, it inflates.
Todd

I also like Woodward's hypothesis of exposing the negative bare mass of the electron in the ADM model, being the exotic matter, described chapters 7 and 8 in his book.
« Last Edit: 07/31/2015 04:12 PM by flux_capacitor »

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