Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1803504 times)

Offline txdrive

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Not that this all matters, because 1: Shawyer's formula for computing thrust has been definitely falsified by EagleWorks down to 1..2%

EW did not use the correct excitation frequency as per the SPR resonance method, so nothing is disproven.
They tried a whole bunch of resonant modes, at resonance. They really really tried hard to see thrust where there isn't any (to the point of seeing thrust into their errors, at least for now, but I'm sure it'll eventually get resolved).

They're incredibly biased in favour of it working and incredibly motivated to get it working, but all they get is a tiny inconsistent torque of unknown origin (given 180 degree rotation disparity, likely not even a force acting on the drive itself), at a tiny fraction of Shawyer's predicted thrust.
« Last Edit: 06/01/2015 02:54 AM by txdrive »

Offline TheTraveller

Not that this all matters, because 1: Shawyer's formula for computing thrust has been definitely falsified by EagleWorks down to 1..2%

EW did not use the correct excitation frequency as per the SPR resonance method, so nothing is disproven.
They tried a whole bunch of resonant modes, at resonance. They really really tried hard to see thrust where there isn't any (to the point of seeing thrust into their errors, at least for now, but I'm sure it'll eventually get resolved)

But did they ask Shawyer for assistance? I mean they were trying to replicate his EM Drive, getting nowhere but seemingly ignoring him, his equations and methods to calc frustum resonance at virtually any TX,m,n,p mode you desire.

As you can see from my EM Drive Calculator, the process is simple and straight forward.

BTW I thought there was only a brief test without a dielectric inside the cavity? the SPR method doesn't use dielectrics, Shawyer has said so, yet EW put them in.
« Last Edit: 06/01/2015 02:59 AM by TheTraveller »
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Offline txdrive

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Not that this all matters, because 1: Shawyer's formula for computing thrust has been definitely falsified by EagleWorks down to 1..2%

EW did not use the correct excitation frequency as per the SPR resonance method, so nothing is disproven.
They tried a whole bunch of resonant modes, at resonance. They really really tried hard to see thrust where there isn't any (to the point of seeing thrust into their errors, at least for now, but I'm sure it'll eventually get resolved)

But did they ask Shawyer? I mean they were trying to replicate his EM Drive, getting nowhere but seemingly ignoring his equations and methods to calc frustum resonance at virtually any TX,m,n,p mode you desire.

As you can see from my EM Drive Calculator, the process is simple and straight forward.
At the risk of repeating every competent physicist that ever came into this thread: Shawyer's calculations are completely confused even in simplest details. There's no point of contact between what he's doing and the discipline known as "physics".

What are you suggesting here, that EagleWorks didn't actually run the cavity at the resonance? From what I recall they had actually measured the Q with a sense antenna. There's a well known formula for calculating resonant modes of a truncated cone. It is certainly correct - tested to death in many practical devices. And they're also tuning the frequency to hit the actual resonance if the shape is a little off (due to thermal heating for instance).
« Last Edit: 06/01/2015 03:00 AM by txdrive »

Offline aero

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I got the complex permittivity coded into my control file using a single frequency formula, the drive frequency. The only thing that is systematially repeatable in Harminv is that the Q drops dramatically, and of course for no dielectric, the resonant frequencies go up.
 
For the two frequencies at which Harminv detects resonance, I get:

 Q                                  epsilon
3220.3403488183        e = 2.7 + i 0.00135
907.4933785116

 Q
316800.187593835       e = 2.7 
30154.1161727352

 Q
900280.7079367            e = 1
35859.5072834475

The frequency only changes (up 10% to 15%) for e = 1 and none of the other outputs show any systematic changes.

Note: This is using the Brady cavity model that I posted yesterday.
« Last Edit: 06/01/2015 03:10 AM by aero »
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Offline TheTraveller

At the risk of repeating every competent physicist that ever came into this thread: Shawyer's calculations are completely confused even in simplest details. There's no point of contact between what he's doing and the discipline known as "physics".

Yet SPR and the Chinese calculate resonance their way and measure significant thrust, while EW, following their conventional COMSOL approach, see nothing.

4 to 6 weeks from now, I'll open up the streaming links and you can watch to see if there is thrust or not.
« Last Edit: 06/01/2015 03:30 AM by TheTraveller »
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Offline Taven

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Not that this all matters, because 1: Shawyer's formula for computing thrust has been definitely falsified by EagleWorks down to 1..2%

EW did not use the correct excitation frequency as per the SPR resonance method, so nothing is disproven.
They tried a whole bunch of resonant modes, at resonance. They really really tried hard to see thrust where there isn't any (to the point of seeing thrust into their errors, at least for now, but I'm sure it'll eventually get resolved)

But did they ask Shawyer? I mean they were trying to replicate his EM Drive, getting nowhere but seemingly ignoring his equations and methods to calc frustum resonance at virtually any TX,m,n,p mode you desire.

As you can see from my EM Drive Calculator, the process is simple and straight forward.
At the risk of repeating every competent physicist that ever came into this thread: Shawyer's calculations are completely confused even in simplest details. There's no point of contact between what he's doing and the discipline known as "physics".

They don't have to be right, they just have to produce thrust. TheTraveller is attempting to reproduce Shawyer's thrust and is following the data to do so. It doesn't matter if the equations that lead him there are off, or are merely coincidence, or not even correct, his goal is thrust. Shawyers work has lead to producing thrust consistently and potentially explains the thrust of others, so if the aim is to replicate it, that's the starting point. If every competent physicist that ever came into this thread knew exactly what was going on and the math behind it, this discussion wouldn't exist and the EmDrive wouldn't be producing thrust.
« Last Edit: 06/01/2015 03:50 AM by Taven »

Offline zen-in

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At the risk of repeating every competent physicist that ever came into this thread: Shawyer's calculations are completely confused even in simplest details. There's no point of contact between what he's doing and the discipline known as "physics".

Yet SPR and the Chinese calculate resonance their way and measure significant thrust, while EW, following their conventional COMSOL approach, see nothing.

4 to 6 weeks from now, I'll open up the streaming links and you can watch to see if there is thrust or not.

I don't believe "streaming links" will convince me that Shawyer's experiments show any thrust.   Youtube has a lot of that already.   To convince me and any physicists who might be still reading your frequent posts you will have to supply raw test data and some proof that his experiments have been replicated.   Extraordinary claims require extraordinary proof.

Offline TheTraveller

I don't believe "streaming links" will convince me that Shawyer's experiments show any thrust.   Youtube has a lot of that already.   To convince me and any physicists who might be still reading your frequent posts you will have to supply raw test data and some proof that his experiments have been replicated.   Extraordinary claims require extraordinary proof.

There will be data, real time data and all the data logged and downloadable.

As for results, EW gets 30uN or the mass of 1 snowflake of thrust and the Flight Thruster get 170mN of thrust.

EW:     000,030uN with a dielectric and resonate frequencies that are discovered via spectrum scan or COMSOL.
SPR:    170,000uN with no dielectric. Calculated resonance frequency, from actual frustum dimensions.
NWPU: 710,000uN with no dielectric. Calculated resonance frequency from actual frustum dimensions.

I too find it hard to accept EW 30uNs (snowflake mass) of thrust is real but not the Flight Thrusters 170,000uNs of thrust nor the Chinese massive 710,000uNs of thrust.

Massive difference. Like the difference between Chalk and Cheese.
« Last Edit: 06/01/2015 04:23 AM by TheTraveller »
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Offline Mulletron

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Offline WarpTech

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...

What are you suggesting here, that EagleWorks didn't actually run the cavity at the resonance? From what I recall they had actually measured the Q with a sense antenna. There's a well known formula for calculating resonant modes of a truncated cone. It is certainly correct - tested to death in many practical devices. And they're also tuning the frequency to hit the actual resonance if the shape is a little off (due to thermal heating for instance).

The point missing is, if you tune it for the highest Q and resonance, it reduces the thrust. I've proven to myself anyway, that the thrust happens due to the interference between the standing wave k and the evanescent wave Beta, phase factors.  Where they interfere is where the phase shift is happening due to attenuation, as it propagates into the small end. Optimal thrust will occur when the amplitude of the standing waves is nearly the same as the amplitude of the evanescent waves and the two are out of phase. If you concentrate only on higher Q at resonance like EW did, it will minimize the evanescent waves that drive the thrust. Therefore, a lower Q is more likely to have positive results. Perhaps @TheTraveler's point is true, that had EW tested it at the Df frequency, it may have provided more thrust. So nothing is falsified by their test except the idea that they understand how it works.

I'm still trying to crunch all this into design equations that are hopefully, more accurate and informative. It may take me a while.

Todd
« Last Edit: 06/01/2015 04:49 AM by WarpTech »

Offline TheTraveller

...

What are you suggesting here, that EagleWorks didn't actually run the cavity at the resonance? From what I recall they had actually measured the Q with a sense antenna. There's a well known formula for calculating resonant modes of a truncated cone. It is certainly correct - tested to death in many practical devices. And they're also tuning the frequency to hit the actual resonance if the shape is a little off (due to thermal heating for instance).

The point missing is, if you tune it for the highest Q and resonance, it reduces the thrust. I've proven to myself anyway, that the thrust happens due to the interference between the standing wave k and the evanescent wave Beta, phase factors.  Where they interfere is where the phase shift is happening due to attenuation, as it propagates into the small end. Optimal thrust will occur when the amplitude of the standing waves is nearly the same as the amplitude of the evanescent waves and the two are out of phase. If you concentrate only on higher Q at resonance like EW did, it will minimize the evanescent waves that drive the thrust. Therefore, a lower Q is more likely to have positive results. Perhaps @TheTraveler's point is true, that had EW tested it at the Df frequency, it may have provided more thrust. So nothing is falsified by their test except the idea that they understand how it works.

I'm still trying to crunch all this into design equations that are hopefully, more accurate and informative. It may take me a while.

Todd

Please correct me if I misunderstood but if the small end operates just above cutoff, as Shawyer suggests for highest Df and thrust, there will be no evanescent waves generated?
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Offline aero

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What are you suggesting here, that EagleWorks didn't actually run the cavity at the resonance? From what I recall they had actually measured the Q with a sense antenna. There's a well known formula for calculating resonant modes of a truncated cone. It is certainly correct - tested to death in many practical devices. And they're also tuning the frequency to hit the actual resonance if the shape is a little off (due to thermal heating for instance).

The point missing is, if you tune it for the highest Q and resonance, it reduces the thrust. I've proven to myself anyway, that the thrust happens due to the interference between the standing wave k and the evanescent wave Beta, phase factors.  Where they interfere is where the phase shift is happening due to attenuation, as it propagates into the small end. Optimal thrust will occur when the amplitude of the standing waves is nearly the same as the amplitude of the evanescent waves and the two are out of phase. If you concentrate only on higher Q at resonance like EW did, it will minimize the evanescent waves that drive the thrust. Therefore, a lower Q is more likely to have positive results. Perhaps @TheTraveler's point is true, that had EW tested it at the Df frequency, it may have provided more thrust. So nothing is falsified by their test except the idea that they understand how it works.

I'm still trying to crunch all this into design equations that are hopefully, more accurate and informative. It may take me a while.

Todd

Please correct me if I misunderstood but if the small end operates just above cutoff, as Shawyer suggests for highest Df and thrust, there will be no evanescent waves generated?

Remember that this is still a real physical system, there are no lines in the sand or brick walls over or through which nothing passes. This is using a noisy magnatron, there are frequencies both higher and lower than the design frequency. There will be evanescent waves created by the lower frequencies. The only penalty is that there may be fewer, at the cost of slightly higher resonance and/or lower power consumption. With those costs it becomes a trade-off as to which side of the cut-off to err on. Only careful experiments will determine that and we all hope that it doesn't end up requiring each EM thruster to be a custom device. We seek a model that will tell us exactly but we need careful experimentation to develop needed data for the model.
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Offline TheTraveller

Remember that this is still a real physical system, there are no lines in the sand or brick walls over or through which nothing passes. This is using a noisy magnatron, there are frequencies both higher and lower than the design frequency. There will be evanescent waves created by the lower frequencies. The only penalty is that there may be fewer, at the cost of slightly higher resonance and/or lower power consumption. With those costs it becomes a trade-off as to which side of the cut-off to err on. Only careful experiments will determine that and we all hope that it doesn't end up requiring each EM thruster to be a custom device. We seek a model that will tell us exactly but we need careful experimentation to develop needed data for the model.

Good point. But also need to factor in how close the frustum Df is to 1.0 at the SPR method resonate frequency. The farther below 1.0 the design Df gets, the more head room on the frequency to vary around resonance and the small end stays well above cutoff. If the Df was say 0.98, well the small end is just barely above cutoff and yes you could see some evanescent waves being formed as the guide wavelength at the small end dips below cutoff.

However for my Flight Thruster replications, I'm using a narrow band Rf generator that I can step in 1kHz increments. The frequency range to be used will be well above the small end cutoff as the design Df is ~0.65. As such don't expect any evanescent waves to be generated.

According to the EM Drive Calculator, if my cavity achieves a Q of 50,000, I should see around 20mN of thrust or around 2gf at 100W input.

Once I get my 1st unit well settled in, I do plan to try to get a unit operating at Df 0.95 and see what happens when it dips into cutoff territory. With the 1kH increments of the Rf generator, under USB control from my laptop, it is possible to gather such data.
« Last Edit: 06/01/2015 05:37 AM by TheTraveller »
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Offline zen-in

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What are you suggesting here, that EagleWorks didn't actually run the cavity at the resonance? From what I recall they had actually measured the Q with a sense antenna. There's a well known formula for calculating resonant modes of a truncated cone. It is certainly correct - tested to death in many practical devices. And they're also tuning the frequency to hit the actual resonance if the shape is a little off (due to thermal heating for instance).

The point missing is, if you tune it for the highest Q and resonance, it reduces the thrust. I've proven to myself anyway, that the thrust happens due to the interference between the standing wave k and the evanescent wave Beta, phase factors.  Where they interfere is where the phase shift is happening due to attenuation, as it propagates into the small end. Optimal thrust will occur when the amplitude of the standing waves is nearly the same as the amplitude of the evanescent waves and the two are out of phase. If you concentrate only on higher Q at resonance like EW did, it will minimize the evanescent waves that drive the thrust. Therefore, a lower Q is more likely to have positive results. Perhaps @TheTraveler's point is true, that had EW tested it at the Df frequency, it may have provided more thrust. So nothing is falsified by their test except the idea that they understand how it works.

I'm still trying to crunch all this into design equations that are hopefully, more accurate and informative. It may take me a while.

Todd

Again, this doesn't make any sense.   When the RF that is coupled into a cavity is at the resonant frequency the Q will be maximal.   That means the return loss is also at a maximum and almost all the power goes into the cavity.   Any frequency that results in a lower Q will have a lower return loss and so there will be more power reflected back from the cavity.  If the return loss is 10 dB lower at the frequency with a lower Q and "better for producing thrust"  then the effective RF power transmitted to the cavity is just 1/10 of the power transmitted to the cavity at the resonant frequency where the Q is maximal.   So maybe less RF power is the key.   Reduce the RF power and get more thrust.   Reduce it further and get even more thrust...  ad infinitum until with no power you get infinite thrust.
« Last Edit: 06/01/2015 05:42 AM by zen-in »

Offline Mulletron

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« Last Edit: 06/01/2015 08:09 AM by Mulletron »
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Offline dustinthewind

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@ Mulltron sorry I can't help more and hopefully I understand this correctly.  I think I understand a little bit about what Chirality is in that it is the apparent spin of a charge or particle with respect to its velocity but there is only spin up or spin down or fractions of spin up and down (quantum in nature).  If many electrons get separated by spin with a magnet they make two spots instead of spreading evenly. 

Spin being similar to a current in a conductor loop if an observer is moving relative to the loop then by relativity there appears to be charge bunching up on one side of the loop.  Time passes by slower for the negative current with a higher relative velocity so there is a buffer effect which can be paralleled to pancaking (an Edward Purcell term from his book) of electric fields.  The positive lattice atoms in a wire don't have rotation and are not effected the same way as the negative charges moving in a circle.  This resulting dipole electric field should correspond to the magnetic field (1/r^3 behavior outside the loop and the constant field inside.)  I guess the electron appears to have such a spin and by relativity to bunch up like a current loop with respect to relative velocity [it has its own magnetic field].  That is probably the limit of what I know about it.  The anomaly appears to be more in depth than I know and concerning conservation of chrial current I think.  Hopefully I didn't butcher anything terribly.

For anyone interested in what Chirality is. http://en.wikipedia.org/wiki/Chirality_(physics)

On another note, I was about to go to bed when it hit me that I saw an adjustable cavity some where in the thread.  An adjustable cavity I would think should be the same as having a non-adjustable cavity but changing the frequency.  Maybe a different way of testing changing the frequency is instead slightly changing the cavity dimensions.   

One downside however is with the end-plate adjustable I would imagine that might interfere with some TM modes?  Current would have to jump the air gap to get to the adjustable plate.  Maybe that would be desirable/undesirable. 
« Last Edit: 06/01/2015 10:08 AM by dustinthewind »

Offline Paul Novy

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Some theories have thrust inversely proportional to frequency (hence this one at 24 GHz should have ~10 times less thrust than the ones at 2.4 GHz so far tested, based on inverse of linear proportionality alone)

So as it is inversely proportional to frequency the higher photon energy has no influence on the mechanism of action?


25 GHz - e-4 eV
2.5 GHz  - e-5 eV


I find this replication rather interesting because of somewhat different approach but as their RF source is 0.0something Watts I would not expect it to show measurable results.

Offline OttO

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I found this paper interesting:

http://www.jpier.org/PIER/pier151/07.15022404.pdf

Fig 6-8"gradient force acting on a water drop of r = 10μm radius in a rectangular waveguide at the xy plane due to an evanescent wave"

I understand that it is well known by specialists but the longer I take a look at all the stuff that is presented in this thread, the more fun it becomes (and my math is improving... :))

Online Rodal

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I found this paper interesting:

http://www.jpier.org/PIER/pier151/07.15022404.pdf

Fig 6-8"gradient force acting on a water drop of r = 10μm radius in a rectangular waveguide at the xy plane due to an evanescent wave"

I understand that it is well known by specialists but the longer I take a look at all the stuff that is presented in this thread, the more fun it becomes (and my math is improving... :))
Thank you, excellent, very relevant, very new (2015) paper.

A gradient force in the waveguide, the evanescent wave propagates at a frequency which is less than the cutoff frequency.

The authors calculate the radiation pressure acting on a particle placed in a rectangular waveguide for both propagating and evanescent waves using the Lorentz force.

A particle in a rectangular waveguide can be pulled towards the light source or pushed away from the light source just by varying the frequency around the waveguide cutoff frequency.

All of the fields and forces analytical calculations are validated using COMSOL Multiphysics Finite Element Analysis

How did you find it?
« Last Edit: 06/01/2015 12:48 PM by Rodal »

Offline Paul Novy

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What boggles my mind now is a thought experiment on replication of the experiment through different EM wavelengths to check what is its effect on the phenomena. Maybe it would give us better insight on what's going on.

It would be inconvenient (imagine 100000 mile frustum for ELF), or technically difficult for THz submilimiter, or the device would be to small as for infrared and above, or we could not pump considerable amount of energy in resonance. Besides that we are short on X-ray and gamma lasers. But maybe if we figure out what's behind all this the most effective would be array of microscopic "engines" pumped by visible light laser?

Just thinking out loud.

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