Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 3126250 times)

Offline Fugudaddy

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Shawyer opinion: He found something. If he knew what, this group would have figured out his math by now. He thinks he has, Boeing seems to think he has. I think there's 'something else' happening. *shrug*

Science question, straightforward.
Thermodynamic/aerodynamic effects- shouldn't they be neutralized if the thing is tested in a 'right to left' then 'left to right' configuration?

Science question- more complex.

I don't math; but I get the language of symbology.  This is about gravity and those effects that EW seemed to measure.

So let's call 'p' a point of gravity in our hypothetical fustrum that is strong enough to create a 'gravitational lensing' effect. So waves can't pass over/through p, but have to pass around it.

Waves bouncing around in general (coming into the space) will pass through and carry on the other side, balancing out the effects of p.

Waves coming straight back up the narrowing (or expanding, whichever) are perturbed enough by p so that by the time the wave 'comes together' on the other side of p, the size of the wave has changed from where it was, so its energy (or something) has to change to match its new size, right?

If that is the case, would reducing 'p' enough so that the waves are disturbed, but not necessarily 'broken' by p be enough to introduce this energy change and if so, would that be enough to help explain where that extra 'push' is coming from?

There's no pushing off of QV or anything, since waves that pass around galaxies do so without any magic hoohoo. But the difference there is that's in space, so there's no 'changing' the wave dimensions since the 'sides' of the space those waves are moving through is, in effect, infinite.

It's a vague handwaving understanding, from the thought of the waves in the fustrum somehow managing to create a mini black hole for a moment, what would happen then?

Thanks. :)

(just as an aside- would *love* to see more DiY results. Some measurable result is far more important than proving the most effective result possible, imho).

Offline Rodal

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The Frank Davies mode analysis (attached) did a really good covering most of the frustum TEmnp and TMmnp modes.

TE013 is missing and may be of interest as the E field intensity at the small end may be very large.

Can anybody supply the E and H field analysis as NASA did but for the missing TE013 mode? It will be worth your time.
There are an infinite (yes infinite) number of natural frequencies in the real world, that are missing from the calculations because they have a natural frequency beyond the range covered in the eigenvalue analysis (which goes to 2.5 GHz).

In order to accurately model the higher natural frequencies, a finer discretization mesh is needed.  To obtain all the infinite number of natural frequencies one would need an infinite number of finite elements.  The matrix that needs to be inverted to get the eigenvalues grows with the square of the finite element mesh, so it quickly becomes overwhelming.

cylTE013 as well as cylTE01p with p equal or greater than 3 have a frequency higher than 2.5 GHz for the NASA Eagleworks geometry.

There are a number of other mode shapes next to cylTE013.  Is there any particular reason why you are interested in cylTE013 ?


I write cylTEmnp because these are mode shapes close to the equivalent mode shape in a cylinder, but there are other mode shapes in the truncated cone that have no close analog in the cylinder.
« Last Edit: 05/25/2015 06:31 pm by Rodal »

Offline TheTraveller

Is there any particular reason why you are interested in TE013 ?

More breadcrumbs have appeared :)

Was told by Roger Shawyer to use TE013 mode to design my Flight Thruster replication. He said otherwise I was on the right track. Appears he is monitoring this forum.
« Last Edit: 05/25/2015 06:32 pm by TheTraveller »
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Offline mwvp

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1) UL certified Copper epoxy will be used to join the 2 end flanges to the frustum and then cover the butt joint.
http://www.supergluecorp.com/super-glue/epoxies/copper-bond

Does anyone have an opinion on this joining method?


I would solder or plate, as was recommended. The glue, from the MSDS, is 90-100% epoxy. Surely is non-conductive, not to mention that because of the skin effect even conductive glue particles could be resistive and a place for Q attenuation and arcing.

I wonder if Nasa was limited to 30W because of arcing in the vacuum chamber? That what killed their RF amp? A low mode high-Q cavity may high problems around sharp points and edges.

Didn't one of the photos closeups of the inside of Shawyers frustrum show a link-coupling near the inside of the cavity wall? It was a dozen or so pages back in the 2nd thread.

I'm half-ready to build one of these. I'll have a look at Meep and simulating it, then buzzing out some flimsy hastily-built cavities to figure out the feedpoint.

Offline zen-in

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...

Quote
Safe and easy to use Copper-Bond® is UL listed for joining copper tube used in fire sprinkler systems and NSF approved for hot and cold water systems.

As my max power input is 100W, I feel the joint temperatures should be well with-in the UL rating.

There will also be alum supporters as per the 1st Experimental device, so will get additional surface area to radiate heat. All this will be inside a sealed Faraday Cage as Shawyer used.

The UL rating is immaterial to your application.  Plumbing fittings are inherently much stronger than all other types because one tube is inside the other.   Since you will be using the epoxy like putty the advertised strength will not be there.   One option to consider is to assemble the parts and hold it together with light gauge iron wire before soldering it.   Wrapping the wire around everything will hold it in place when it is soldered.   The Copper doesn't expand very much when lead solder is used.

Offline TheTraveller


1) UL certified Copper epoxy will be used to join the 2 end flanges to the frustum and then cover the butt joint.
http://www.supergluecorp.com/super-glue/epoxies/copper-bond

Does anyone have an opinion on this joining method?


I would solder or plate, as was recommended. The glue, from the MSDS, is 90-100% epoxy. Surely is non-conductive, not to mention that because of the skin effect even conductive glue particles could be resistive and a place for Q attenuation and arcing.

I wonder if Nasa was limited to 30W because of arcing in the vacuum chamber? That what killed their RF amp? A low mode high-Q cavity may high problems around sharp points and edges.

Didn't one of the photos closeups of the inside of Shawyers frustrum show a link-coupling near the inside of the cavity wall? It was a dozen or so pages back in the 2nd thread.

I'm half-ready to build one of these. I'll have a look at Meep and simulating it, then buzzing out some flimsy hastily-built cavities to figure out the feedpoint.

Thanks for the comments.

Will be putting a thin & fine copper mesh over the joints. Then 2 thin layers of silver epoxy to electrically bond the copper mesh to the copper frustum. Next use the copper epoxy as an overlayer to give added structural strength. No epoxy will be inside the cavity.

I'm paying for laser cut accuracy so the ends are parallel to each other by very small fraction of a degree. I fell this is needed to get the highest Q to make up for my low 100W power.
« Last Edit: 05/25/2015 07:19 pm by TheTraveller »
It Is Time For The EmDrive To Come Out Of The Shadows

Offline TheTraveller


...

Quote
Safe and easy to use Copper-Bond® is UL listed for joining copper tube used in fire sprinkler systems and NSF approved for hot and cold water systems.

As my max power input is 100W, I feel the joint temperatures should be well with-in the UL rating.

There will also be alum supporters as per the 1st Experimental device, so will get additional surface area to radiate heat. All this will be inside a sealed Faraday Cage as Shawyer used.

The UL rating is immaterial to your application.  Plumbing fittings are inherently much stronger than all other types because one tube is inside the other.   Since you will be using the epoxy like putty the advertised strength will not be there.   One option to consider is to assemble the parts and hold it together with light gauge iron wire before soldering it.   Wrapping the wire around everything will hold it in place when it is soldered.   The Copper doesn't expand very much when lead solder is used.

Thanks.  Good points. Will think on your and others suggestions.
It Is Time For The EmDrive To Come Out Of The Shadows

Offline Notsosureofit

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@WarpTech raises a very good point.  Any system which provides propellant-less acceleration should also work as an accelerometer.   Photon resonators are already used as accelerometers. (and by extension, gravity wave detectors)
« Last Edit: 05/25/2015 07:43 pm by Notsosureofit »

Offline Rodal

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Is there any particular reason why you are interested in TE013 ?

More breadcrumbs have appeared :)

Was told by Roger Shawyer to use TE013 mode to design my Flight Thruster replication. He said otherwise I was on the right track. Appears he is monitoring this forum.

                            Truncated cone    Truncated cone    Truncated cone      Approximation using
Mode Shape          Rodal Exact          NASA COMSOL    Difference             Cylindrical Cavity  (GHz)
                            solution (GHz)      solution (GHz)     NASA vs. exact     Diameter=Mean (*)
                           
TE011                  1.78972              1.77048             1.08%                   1.79324

TE012                  2.20244              2.1794               1.05%                   2.12264

TE013                  2.65493              ?                         ?                           2.57980

Note:  Rodal Truncated Cone exact solution has spherical ends, COMSOL FEA and Cylindrical Soltution have flat ends.

(*) Cylindrical Solution http://en.wikipedia.org/wiki/Microwave_cavity#Cylindrical_cavity
using Diameter = (1/2)(bigDiameter  + smallDiameter )



Geometrical dimensions: 

bigDiameter = 11.00 inches used by Rodal, 11.01 inches used by Jerry Vera for his COMSOL FEA solution
smallDiameter = 6.25 inches;
axialLength = 9 inches;

spherical coordinate r1 = 0.300789 meters

spherical coordinate r2 = 0.529389 meters
 
cone half angle = 14.7827 degrees

speed of light in medium = 299792458 meter/second (Vacuum)

« Last Edit: 05/25/2015 10:22 pm by Rodal »

Offline WarpTech

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@WarpTech raises a very good point.  Any system which provides propellant-less acceleration should also work as an accelerometer.   Photon resonators are already used as accelerometers. (and by extension, gravity wave detectors)

Exactly, that's where Dr. McCulloch's work comes in, though I'm not well versed in his model yet. Accelerating a cavity full of energy, oscillating in modes will cause a doppler shift to propagate through. Here, that doppler shift is being caused by energy lost to the cavity.

Momentum is being input to the cavity via the microwaves, dp_in/dt, and is stored in the oscillating modes, Q*dp_in/dt. The rate of dissipation of that momentum, -dp/dt = F, will determine the forces on each surface. If that rate is not simply a constant of the metal, but a variable of the geometry, there will be asymmetrical forces, velocities and doppler shifts. Agreed?

Todd



Offline X_RaY

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Is there any particular reason why you are interested in TE013 ?

More breadcrumbs have appeared :)

Was told by Roger Shawyer to use TE013 mode to design my Flight Thruster replication. He said otherwise I was on the right track. Appears he is monitoring this forum.


Mode Shape          Rodal Exact solution (GHz)       NASA COMSOL FEA solution (GHz)  Difference

TE011                  1.78972                                 1.77048                                       1.08%

TE012                  2.20244                                  2.1794                                        1.05%

TE013                  2.65493                                  ?                                                  ?

Note:  Rodal solution has spherical ends, COMSOL FEA has flat ends.

Geometrical dimensions: 

bigDiameter = 11.00 inches used by Rodal, 11.01 inches used by Jerry Vera for his COMSOL FEA solution
smallDiameter = 6.25 inches;
axialLength = 9 inches;

spherical coordinate r1 = 0.300789 meters

spherical coordinate r2 = 0.529389 meters
 
cone half angle = 14.7827 degrees

speed of light in medium = 299792458 meter/second (Vacuum)



Hello i am new in this forum. Based on my own simple model(flat end plates) the frequency has to be approximately 2.52GHz.
I hope this is helpfull :)

Offline R.W. Keyes

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There's much on this subject I don't understand. I feel like if I had another twenty years to study this, I might be able to have a better grasp.

But there are some things I might be able to address, because of some of the practical experience I've had in RF. If worried about the shift away from resonance due to thermal expansion in a high-Q frustum, would a useful remedy be to choose a longer wavelength, and larger frustum, so that the deformation is a small portion of a wavelength? Now, I understand that there may be other reasons to want to operate at a shorter wavelength (more power).

I have noted that Shawyer uses a silicon carbide structural base, and then plates this with a superconductor. Silicon carbide is very stiff in regards to temperature changes (note: now it can also be 3D-printed). At what wavelengths is it sufficiently stiff at a superconducting temperature?

Offline Rodal

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..If worried about the shift away from resonance due to thermal expansion in a high-Q frustum, would a useful remedy be to choose a longer wavelength, and larger frustum, so that the deformation is a small portion of a wavelength? Now, I understand that there may be other reasons to want to operate at a shorter wavelength (more power)...

For a simple uniaxial case, for a plate (plane stress state):

Thermal Strain = coefficientOfThermalExpansion *(delta T)
                       = (delta L) / L  (if free to change in length)

For a given change in temperature (delta T), the longer L, the greater the change in length due to thermal expansion if unrestrained.  Thermal strain is independent of length.



Thermal Stress = (Thermal Strain) *ModulusOfElasticity /(1-PoissonRatio2
                       = ( ModulusOfElasticity /(1-PoissonRatio2)  ) *coefficientOfThermalExpansion *(delta T)

(if plate is restrained, and prevented from thermal expansion)

For a given change in temperature (delta T), the thermal strain and stress are the same, governed by material properties (coefficient of thermal expansion, modulus of elasticity and Poisson's ratio). 
« Last Edit: 05/25/2015 09:44 pm by Rodal »

Offline TheTraveller

There's much on this subject I don't understand. I feel like if I had another twenty years to study this, I might be able to have a better grasp.

But there are some things I might be able to address, because of some of the practical experience I've had in RF. If worried about the shift away from resonance due to thermal expansion in a high-Q frustum, would a useful remedy be to choose a longer wavelength, and larger frustum, so that the deformation is a small portion of a wavelength? Now, I understand that there may be other reasons to want to operate at a shorter wavelength (more power).

I have noted that Shawyer uses a silicon carbide structural base, and then plates this with a superconductor. Silicon carbide is very stiff in regards to temperature changes (note: now it can also be 3D-printed). At what wavelengths is it sufficiently stiff at a superconducting temperature?

Shawyers solution for the high Q Flight Thruster, which I'm following,  is to use a variable frequency Rf generator that samples the cavity E field and varies the frequency to stay in resonance. Then thermal changes to generated thrust should be minimised.
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Offline WarpTech

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I think this paper may be of some interest for those not so familiar with tensor equations.

https://www.dropbox.com/s/wxzz2nf3dlqvibc/Puthoff_EnergyDensity_0904.1617.pdf?dl=0

"Abstract: It is well understood that various alternatives are available within EM theory for the definitions of energy density, momentum transfer, EM stress-energy tensor, and so forth. Although the various options are all compatible with the basic equations of electrodynamics (e.g., Maxwell’s equations, Lorentz force law, gauge invariance), nonetheless certain alternative formulations lend themselves to being seen as preferable to others with regard to the transparency of their application to physical problems of interest. Here we argue for the transparency of an option based on use of the EM potentials alone."

I like Puthoff's method of explaining things, he is very clear and doesn't overwhelm me with too much information.

So, remember yesterday when I said the Divergence of S and of n*T were zero? Turns out, that's only true if the energy is already stored in the cavity and the microwave source is turned "off". As long as the source of microwaves is turned on, there is a non-zero divergence corresponding to the input power flux. So I take it back, the divergence is not zero with the microwave motor running.

Todd

Offline Rodal

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How the Maser was invented also is useful to get us to think about the nature of the EM Drive in more conventional ways.  There are three keys to the Maser's operation:

1) Find a gas which energetically emits at the same frequency at which we want to operate the cavity.  In the first Maser, they used the Ammonia molecule because after WWII microwave technology had been developed for Radar, and it was noted that the ammonia molecule happens to strongly emit at 23.79 GHz ( https://en.wikipedia.org/wiki/Ammonia#Structure ).

2) Segregate the population of molecules in the gas so that the stimulated emission overrides absorption.  (In the first maser this was done by physically segregating the lower energy levels of the ammonia gas).

3) Intensify the action by using a resonant  cavity of high Q.


Scientists after WWII took advantage of the already known fact that ammonia gas molecules react to a non-uniform electric field in ways that depend on the energy levels of the ammonia gas molecules.  This offered a way to segregate the high-energy molecules from the low energy molecules.  In the first Maser ammonia gas was made to flow through a cylinder where an electric field draws the low-energy molecules away to the inner surfaces of the cylinder while the high-energy molecules of ammonia flow through, into a cavity.  With a large excess of high-energy molecules the cavity is set for Maser action.  A 24 GHz photon entering this energy-laden gas soon encounters  a high energy molecule and knocks out another 24 GHz photon , which results in amplification.  However, without further aid this process is not intense enough to build up usable strength.
It was crucial to success that the inventor of the Maser understood there would have to be a way to intensify the action.  The inventor realized that this amplification could be obtained by harnessing the phenomenon of resonance of a cavity: high Q.  The cavity was designed to resonate with standing waves at the same frequency of 24 GHz at which the ammonia gas energetically emits.  In the reverberant space of the cavity the photons are kept rocketing back and forth through the energy-loaded gas so as to build a vigorous sustained oscillation.  The 24 GHz vibration entering the cavity is amplified 100 times in power. 

Hm.  As has been noted many times both Sawyer and Yangs experiments are ran at atmospheric pressure and are furthermore (as far as anyone can tell) well sealed...One defence for this hypotheses is the difference in measured effects between the Yang and Sawyer devices and the Eagleworks vacuum tests.

To me, this is a really crucial bit of info.  If these devices loose this much performance in a vacuum, then are they really all that superior to a photon rocket?  ...

It is indeed noteworthy that although Shawyer has been working on the EM Drive for decades, that no experiment in a vacuum has been reported by Mr. Shawyer.

Prof. Yang has been working on EM Drive experiments since prior to 2010, yet we are in 2015 and we have not yet heard of her performing experiments in a vacuum.

It took NASA Eagleworks less than a year to perform an EM Drive experiment in a vacuum and the results showed significantly less thrust/InputPower than the one measured in air.

So it definitely has to be considered whether the gas molecules inside the EM Drive may not indeed be undergoing segregation between high-energy and low-energy, and whether the gas molecules may be playing a role (beyond the obvious one of air convection, gas exiting the EM Drive under higher pressure than ambient, buoyancy due to higher temperature, etc.)

In this regard it is interesting that Prof. Yang asks the reader to consider the case of a gas of charged particles inside the EM Drive as a means to understand how it is able to accelerate without breaking the law of Conservation of Momentum.

As Todd has been writing, for the EM Drive there appears to be the need of a balance between high Q resonance and absorption.  If there is a gas (air) inside the cavity that has charged particles (some ionization produced within the Microwave cavity), and whose molecules can be segregated by the electric field, then so much the better for this process of amplification (almost like in the Maser).

http://b.gatech.edu/1cX7sXj

http://www.mike-willis.com/Tutorial/gases.htm


http://www.jpier.org/PIERB/pierb15/09.09041706.pdf

http://www1.lsbu.ac.uk/water/microwave_water.html

« Last Edit: 05/26/2015 02:50 am by Rodal »

Offline ThinkerX

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Quote
In this regard it is interesting that Prof. Yang want the reader to consider the case of a gas of charged particles inside the EM Drive as a means to understand how it is able to accelerate without breaking the law of Conservation of Momentum.

As Todd has been writing, for the EM Drive there appears to be the need of a balance between high Q resonance and absorption.  If there is a gas (air) inside the cavity that has charged particles (some ionization produced within the Microwave cavity), and whose molecules can be segregated by the electric field, then so much the better for this process of amplification (just like in the Maser).

So...if I am following this correctly, then even for a spacecraft version, you'd still want the frustum to be pressurized...though possibly with something other than nitrogen/oxygen.  That seems doable, unless the device's continuous operation degrades the atmosphere over time.

Offline deltaMass

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When it all starts becoming too much to comprehend, and a headache begins to develop, the best remedy is to dip one's quantum oar into the quantum vacuum and pull on it a little.  :P

Offline TheUberOverLord

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Would like to thank everyone for such diversified input on this since I have been silently following this topic since "thread one". Personally, I have a deep respect for each persons current thoughts on this.

While I do realize that this is "Way out there!".

Is it possible that whatever reactions/movements AKA "Thrust" could be being caused by the inverse of what's being done to slow down atoms using frequencies of light Atomic telescope brings atoms to standstill by using microwave frequencies to excite virtual particles, dark matter or even dark energy?

I ask because this also seems to at least potentially show a classical to quantum transition taking place in some form.

Unless it turns out that all prior experiments have had the same non discovered faults/flaws inside and outside a vacuum.

Don
EM Drive builders can use these free Interfaces to show their tests live using any IP Cameras in websites Click for live demo examples

Offline rfmwguy

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Would like to thank everyone for such diversified input on this since I have been silently following this topic since "thread one". Personally, I have a deep respect for each persons current thoughts on this.

While I do realize that this is "Way out there!".

Is it possible that whatever reactions/movements AKA "Thrust" could be being caused by the inverse of what's being done to slow down atoms using frequencies of light Atomic telescope brings atoms to standstill by using microwave frequencies to excite virtual particles, dark matter or even dark energy?

I ask because this also seems to at least potentially show a classical to quantum transition taking place in some form.

Unless it turns out that all prior experiments have had the same non discovered faults/flaws inside and outside a vacuum.

Don
Good question don...thread 1 reader myself; got courage to post late in thread 2. All data by shawyer and others leaves open questions. Myself, I believe we are seeing a legit discovery, not yet fully explained. Not sure if its thrust, attraction or  a surfing a space-time wave. We live in warped space time, a gravity well...do these experiments overide our warped space or do they create a new one? This is what fascinates me and why I follow this topic and braintrusts here. Stay tuned!  PS wasn't reading thread for 2 days and now feel 1.4 lightyears behind  ;)

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