Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1799596 times)

Online RonM

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The TE modes are a better way to add stress into the frustum walls and one of the reasons I picked a TE mode.
This bears emphasizing: there has NOT been a single Meep computer run (csv file for sure, and I don't recall seeing any images for TE mode excitation either) for Yang/Shell exciting the frustum in a TE  (transverse electric) mode.  Not even one. Nada. Zilch.
I'm not sure what to do with this Jose. What do you expect me to do? I pretty much know what I'm going to see with this 6 degree frustum and like I said a few pages ago it is a start.

So if your intent is to get me so upset that I leave this forum by beating this dead horse into the ground, continue on this thread and I'll oblige you.

I have the other side of the build to finish so I'm off to the shop.

Shell

Don't let the theorists get you down. No one knows what is going on or even if there is anything going on. They can run all the simulations they want, but we won't know the truth until we have data. Proving or disproving EM drives is in the hands of people like you who can actually build and conduct experiments. Run your EM drive design and see what happens.

Offline DaCunha

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...
The TE modes are a better way to add stress into the frustum walls and one of the reasons I picked a TE mode.
This bears emphasizing: there has NOT been a single Meep computer run (csv file for sure, and I don't recall seeing any images for TE mode excitation either) for Yang/Shell exciting the frustum in a TE  (transverse electric) mode.  Not even one. Nada. Zilch.
I'm not sure what to do with this Jose. What do you expect me to do? I pretty much know what I'm going to see with this 6 degree frustum and like I said a few pages ago it is a start.

So if your intent is to get me so upset that I leave this forum by beating this dead horse into the ground, continue on this thread and I'll oblige you.

I have the other side of the build to finish so I'm off to the shop.

Shell

I smell a tensed atmosphere. This is why I am saying that simulation and optimization work should be the next point but not the present. You will not arrive at a consensus at this moment, because there is no real way to say who is right or wrong (although I am also more convinced by the theory that TE excitation is not possible).

Regardless of optimization, one should try to rebuild a frustrum with the same dimensions and material parameters as Shawyer's original drive (or use EW parameters) and find someone who has the means to let a high power microwave input > 100 kW  inside the frustrum. I am not saying this is an "elegant" way but this is all not about elegance, we have to demonstrate undeniable experimental fact.

Because measurements of µN or mN will not help us either. We need a visible effect to convince the scientific community and we have to convince the scientific community if we want the situation to change.

I think we should concentrate on this.  Who could have the means and could be willing to do this? How can we contact this person/organization?

Let us think and find a way

Offline Flyby

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I doubt it will be in a non-metal material. All those materials, except ceramics, have very low melting points.

so it has to be in a metal...
 
Titanium would be excluded, as I know from colleagues that it prices around 50euro/cm³....expensive to build solid welled objects in... ???

http://www.amazon.com/One-Pound-999-Fine-Titanium/dp/B007RFTC7I shows a one-pound bar of .999
fine titanium selling for less than $50, which is much less than 50 euros per cubic centimeter. Did you mean platinum?
As I do not own a metal 3dprinter, I asked a specialized local firm here for a quote, to see if titanium would be an alternative to (old fashion) bronze casting for an architectural model for blind people.
48€/cm³ was the price i got, which - sadly - landed the 3dprint on par with traditional bronze casting.

In 3dprinting, you pay for a lot more then just the raw materials...
Until recently (some new lowcost kickstarter programs), these specialized industrial grade 3dprinters easily go 300k-800k euro, if not more... and that's why you actually pay that much...

Offline Rodal

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... I am also more convinced by the theory that TE excitation is not possible...
The only reason why the TE mode has not been excited in the Meep software models run by aero is because aero has run Meep models using dipole antennas, as aero has explained, because he did not have a software means ready to simulate a loop antenna in Meep.  TE modes are more readily excited with a loop antenna, rather than a dipole antenna. X-Ray has suggested how to excite a TE mode with a dipole antenna but it requires to be done at a precise location and orientation which depends on the geometry and the precise mode shape (TE012, etc.).   

Theoretically there is no problem in exciting TE012 in the Yang/Shell actual fustrum geometry if suitable means are used.  NASA has reported practical problems exciting TE012 in their NASA report (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf ).

Quote from: Brady et al
Prior to the TM211 evaluations, COMSOL® analysis indicated that the TE012 was an effective thrust generation mode for the tapered cavity thruster being evaluated, so this mode was explored early in the evaluation process. Figure 22 shows a test run at the TE012 mode with an operating frequency of 1880.4 MHz. The measured quality factor was ~22,000, with a COMSOL prediction of 21,817. The measured power applied to the test article was measured to be 2.6 watts, and the (net) measured thrust was 55.4 micronewtons. With an input power of 2.6 watts, correcting for the quality factor, the predicted thrust is 50 micronewtons. However, since the TE012 mode had numerous other RF modes in very close proximity, it was impractical to repeatedly operate the system in this mode, so the decision was made to evaluate the TM211 modes instead

 Shawyer and TheTraveller report that Shawyer has excited TE012 and TE013 in Shawyer's EM Drives and so has Yang reported exciting the TE012 mode.
« Last Edit: 08/03/2015 05:59 PM by Rodal »

Offline TheTraveller

I smell a tensed atmosphere. This is why I am saying that simulation and optimization work should be the next point but not the present. You will not arrive at a consensus at this moment, because there is no real way to say who is right or wrong (although I am also more convinced by the theory that TE excitation is not possible).

Regardless of optimization, one should try to rebuild a frustrum with the same dimensions and material parameters as Shawyer's original drive (or use EW parameters) and find someone who has the means to let a high power microwave input > 100 kW  inside the frustrum. I am not saying this is an "elegant" way but this is all not about elegance, we have to demonstrate undeniable experimental fact.

Because measurements of µN or mN will not help us either. We need a visible effect to convince the scientific community and we have to convince the scientific community if we want the situation to change.

I think we should concentrate on this.  Who could have the means and could be willing to do this? How can we contact this person/organization?

Let us think and find a way

Got that all in hand.

Just realised my small end is a bit too tight, should give it a bit of headroom and use 150mm.

I expect my cordless and battery powered 100W EMDrive and rotary test rig to accelerate from 0 rpm to at least 120 rpm, with heaps of data being recorded and streamed live over the internet.

Will be almost impossible to deny the results, unless someone chooses to believes it is all a very elaborate trick.
« Last Edit: 08/03/2015 04:42 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline TheTraveller

... I am also more convinced by the theory that TE excitation is not possible...
The only reason why the TE mode has not been excited in the Meep software models run by aero is because aero has run Meep models using dipole antennas, as aero has explained, because he did not have a software means ready to simulate a loop antenna in Meep.  TE modes are more readily excited with a loop antenna, rather than a dipole antenna. X-Ray has suggested how to excite a TE mode with a dipole antenna but it requires to be done at a precise location and orientation which depends on the geometry.   

Theoretically there is no problem in exciting TE012 in the Yang/Shell actual fustrum geometry if suitable means are used.  NASA has reported practical problems exciting TE012 in their NASA report (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf ).

Quote from: Brady et al
Prior to the TM211 evaluations, COMSOL® analysis indicated that the TE012 was an effective thrust generation mode for the tapered cavity thruster being evaluated, so this mode was explored early in the evaluation process. Figure 22 shows a test run at the TE012 mode with an operating frequency of 1880.4 MHz. The measured quality factor was ~22,000, with a COMSOL prediction of 21,817. The measured power applied to the test article was measured to be 2.6 watts, and the (net) measured thrust was 55.4 micronewtons. With an input power of 2.6 watts, correcting for the quality factor, the predicted thrust is 50 micronewtons. However, since the TE012 mode had numerous other RF modes in very close proximity, it was impractical to repeatedly operate the system in this mode, so the decision was made to evaluate the TM211 modes instead

 Shawyer and TheTraveller report that Shawyer has excited TE012 and TE013 in Shawyer's EM Drives and so has Yang reported exciting the TE012 mode.

In a cylindrical waveguide, with planar wave fronts, it is simple to excite TE01 mode using a straight 1/4 lambda0 (external wavelength) stub antenna placed 1/4 lambdag (internal TE01 mode guide wavelength) away from an end plate.
« Last Edit: 08/03/2015 04:58 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline X_RaY

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... I am also more convinced by the theory that TE excitation is not possible...
The only reason why the TE mode has not been excited in the Meep software models run by aero is because aero has run Meep models using dipole antennas, as aero has explained, because he did not have a software means ready to simulate a loop antenna in Meep.  TE modes are more readily excited with a loop antenna, rather than a dipole antenna. X-Ray has suggested how to excite a TE mode with a dipole antenna but it requires to be done at a precise location and orientation which depends on the geometry.   

Theoretically there is no problem in exciting TE012 in the Yang/Shell actual fustrum geometry if suitable means are used.  NASA has reported practical problems exciting TE012 in their NASA report (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf ).

Quote from: Brady et al
Prior to the TM211 evaluations, COMSOL® analysis indicated that the TE012 was an effective thrust generation mode for the tapered cavity thruster being evaluated, so this mode was explored early in the evaluation process. Figure 22 shows a test run at the TE012 mode with an operating frequency of 1880.4 MHz. The measured quality factor was ~22,000, with a COMSOL prediction of 21,817. The measured power applied to the test article was measured to be 2.6 watts, and the (net) measured thrust was 55.4 micronewtons. With an input power of 2.6 watts, correcting for the quality factor, the predicted thrust is 50 micronewtons. However, since the TE012 mode had numerous other RF modes in very close proximity, it was impractical to repeatedly operate the system in this mode, so the decision was made to evaluate the TM211 modes instead

 Shawyer and TheTraveller report that Shawyer has excited TE012 and TE013 in Shawyer's EM Drives and so has Yang reported exciting the TE012 mode.

In a cylindrical waveguide, with planar wave fronts, it is simple to excite TE01 mode using a straight 1/4 lambda0 (external wavelength) stub antenna placed 1/4 lambdag (internal TE01 mode guide wavelength) away from an end plate.
Sorry, but that's wrong. Based on your drawing you want to excite the TE11.

EDIT:
I don't like to tell wrong things. ::) To make it clear, it is possible to excite the TE01 with the stub, but the coupling factor would be extremely worse.
Its like, you would use triangle tires on your car ;)
« Last Edit: 08/03/2015 06:44 PM by X_RaY »

Offline X_RaY

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The NASA and others would do it this way for example*.
YES its a loop in the right direction and at that position instead of a monopole  ---> TE01

*and of course there are other possibilities :)
« Last Edit: 08/03/2015 05:39 PM by X_RaY »

Offline Mulletron

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Just want to make sure I am reading Tajmar's paper correctly here.

His testing in hard vacuum only used the magnetic damper and did not feature the oil damper.

Right?

For curiosity's sake, is it even possible to use an oil damper in vacuum? Would the oil boil off and coat everything? What would be a suitable fluid?

« Last Edit: 08/03/2015 06:00 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Flyby

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....
I expect my cordless and battery powered 100W EMDrive and rotary test rig to accelerate from 0 rpm to at least 120 rpm, with heaps of data being recorded and streamed live over the internet.

Will be almost impossible to deny the results, unless someone chooses to believes it is all a very elaborate trick.

Keep in mind that your setup will have to convince the skeptics that claim you're rotation is due to vibration.

So you'll need to be able to have everything switched on , yet not load the cavity and another option that does load the cavity. If the loaded cavity produces circular motion and the unloaded cavity does not, then you have your path to immortality... ;)  but not sooner...

maybe build a deflector+absorption chamber that can absorb of the waves?  ???

Offline TheTraveller

Just want to make sure I am reading Tajmar's paper correctly here.

His testing in hard vacuum only used the magnetic damper and did not feature the oil damper.

Right?

For curiosity's sake, is it even possible to use an oil damper in vacuum? Would the oil boil off and coat everything? What would be a suitable fluid?

Magnetic damper was not used in the last test run. Oil damper was used.
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Offline deltaMass

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I have 3 computers busy running $$$ paying statistical work.  Won't be able to calculate that today, perhaps tonight?. (I only have 2 Mathematica licenses and both are running several hour long programs at the moment).  Mathematica does not allow you to run more simultaneous processes than the number of Mathematica licenses you have.
Interesting - and I know Mathematica allows GPU acceleration. Are you availing yourself of that with a GPU (and if not, why not)?

Offline Rodal

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...Interesting - and I know Mathematica allows GPU acceleration. Are you availing yourself of that with a GPU (and if not, why not)?
Although I have NVIDIA processors. I am not using CUDALink for these programs because my assessment  (after listening to CUDA Wolfram seminars) was that it would not help much for what I'm doing.  I would indeed spend the time writing the CUDA link modules if I would be using  image processing algorithms or standard discrete Fourier transforms, for example.   My assessment maybe outdated: I looked at this more than 1 year ago. 

« Last Edit: 08/03/2015 06:39 PM by Rodal »

Offline deltaMass

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I expect my cordless and battery powered 100W EMDrive and rotary test rig to accelerate from 0 rpm to at least 120 rpm, with heaps of data being recorded and streamed live over the internet.

Will be almost impossible to deny the results, unless someone chooses to believes it is all a very elaborate trick.

Keep in mind that your setup will have to convince the skeptics that claim you're rotation is due to vibration.

So you'll need to be able to have everything switched on , yet not load the cavity and another option that does load the cavity. If the loaded cavity produces circular motion and the unloaded cavity does not, then you have your path to immortality... ;)  but not sooner...

maybe build a deflector+absorption chamber that can absorb of the waves?  ???
Well-devised control experiments are key to successful verification. So here's a suggestion in very rough and qualitative  form. 
Since you plan building a self-contained rotator (which IMO is by far the best demonstration option), you are going to need something to balance the cavity in a diametrically opposite position on the rotor.  So I suggest that the balancer be a dummy load. Same moment of inertia as the cavity, same complex impedance at the same frequency. In this way you can switch between dummy and cavity at will.
« Last Edit: 08/03/2015 06:27 PM by deltaMass »

Offline TheTraveller

... I am also more convinced by the theory that TE excitation is not possible...
The only reason why the TE mode has not been excited in the Meep software models run by aero is because aero has run Meep models using dipole antennas, as aero has explained, because he did not have a software means ready to simulate a loop antenna in Meep.  TE modes are more readily excited with a loop antenna, rather than a dipole antenna. X-Ray has suggested how to excite a TE mode with a dipole antenna but it requires to be done at a precise location and orientation which depends on the geometry.   

Theoretically there is no problem in exciting TE012 in the Yang/Shell actual fustrum geometry if suitable means are used.  NASA has reported practical problems exciting TE012 in their NASA report (http://www.libertariannews.org/wp-content/uploads/2014/07/AnomalousThrustProductionFromanRFTestDevice-BradyEtAl.pdf ).

Quote from: Brady et al
Prior to the TM211 evaluations, COMSOL® analysis indicated that the TE012 was an effective thrust generation mode for the tapered cavity thruster being evaluated, so this mode was explored early in the evaluation process. Figure 22 shows a test run at the TE012 mode with an operating frequency of 1880.4 MHz. The measured quality factor was ~22,000, with a COMSOL prediction of 21,817. The measured power applied to the test article was measured to be 2.6 watts, and the (net) measured thrust was 55.4 micronewtons. With an input power of 2.6 watts, correcting for the quality factor, the predicted thrust is 50 micronewtons. However, since the TE012 mode had numerous other RF modes in very close proximity, it was impractical to repeatedly operate the system in this mode, so the decision was made to evaluate the TM211 modes instead

 Shawyer and TheTraveller report that Shawyer has excited TE012 and TE013 in Shawyer's EM Drives and so has Yang reported exciting the TE012 mode.

In a cylindrical waveguide, with planar wave fronts, it is simple to excite TE01 mode using a straight 1/4 lambda0 (external wavelength) stub antenna placed 1/4 lambdag (internal TE01 mode guide wavelength) away from an end plate.
Sorry, but that's wrong. Based on your drawing you want to excite the TE11.

TE01 and TE11 have very different guide wavelengths and thus different back plate to antenna spacing. As the external frequency is not changed, the 1/4 wave stud antenna length stays the same.

As an example for a waveguide of 200mm dia to be excited at TE01 at 2.45Ghz, the guide wavelength would be 0.1837m and for TE11 the guide wavelength would be 0.1310m. In each case the back plate to the antenna spacing would be 25% of the appropriate guide wavelength, so the excitation of the 2 modes requires a considerable difference in the antenna to the back plate spacing.

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Offline rfmwguy

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Just want to make sure I am reading Tajmar's paper correctly here.

His testing in hard vacuum only used the magnetic damper and did not feature the oil damper.

Right?

For curiosity's sake, is it even possible to use an oil damper in vacuum? Would the oil boil off and coat everything? What would be a suitable fluid?
I'd vote for Beer. Its reclaimable and environmental-friendly  :o

Offline TheTraveller

....
I expect my cordless and battery powered 100W EMDrive and rotary test rig to accelerate from 0 rpm to at least 120 rpm, with heaps of data being recorded and streamed live over the internet.

Will be almost impossible to deny the results, unless someone chooses to believes it is all a very elaborate trick.

Keep in mind that your setup will have to convince the skeptics that claim you're rotation is due to vibration.

So you'll need to be able to have everything switched on , yet not load the cavity and another option that does load the cavity. If the loaded cavity produces circular motion and the unloaded cavity does not, then you have your path to immortality... ;)  but not sooner...

maybe build a deflector+absorption chamber that can absorb of the waves?  ???
Well-devised control experiments are key to successful verification. So here's a suggestion in very rough and qualitative  form. 
Since you plan building a self-contained rotator (which IMO is by far the best demonstration option), you are going to need something to balance the cavity in a diametrically opposite position on the rotor.  So I suggest that the balancer be a dummy load. Same moment of inertia as the cavity, same complex impedance at the same frequency. In this way you can switch between dummy and cavity at will.

There are 4 x 12V 6AH SLA batteries on the table, plus the 100W Rf amp. More than enough to balance the frustum. All items mass centre will be on the same radii from the centre of rotation so the moment of inertial is easy to calculate.

Have not considered a dummy load is necessary as the goal is to accelerate the table from 0 RPM to 120 RPM. Internal frustum pressure will also be monitored and recorded, so no claims of hot N2 jets will pass muster.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline Donosauro

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I doubt it will be in a non-metal material. All those materials, except ceramics, have very low melting points.

so it has to be in a metal...
 
Titanium would be excluded, as I know from colleagues that it prices around 50euro/cm³....expensive to build solid welled objects in... ???

http://www.amazon.com/One-Pound-999-Fine-Titanium/dp/B007RFTC7I shows a one-pound bar of .999
fine titanium selling for less than $50, which is much less than 50 euros per cubic centimeter. Did you mean platinum?
As I do not own a metal 3dprinter, I asked a specialized local firm here for a quote, to see if titanium would be an alternative to (old fashion) bronze casting for an architectural model for blind people.
48€/cm³ was the price i got, which - sadly - landed the 3dprint on par with traditional bronze casting.

In 3dprinting, you pay for a lot more then just the raw materials...
Until recently (some new lowcost kickstarter programs), these specialized industrial grade 3dprinters easily go 300k-800k euro, if not more... and that's why you actually pay that much...

Oops! I didn't catch that the part was to be printed.... That's what I get for not reading more of the thread!

Offline TheTraveller

Just want to make sure I am reading Tajmar's paper correctly here.

His testing in hard vacuum only used the magnetic damper and did not feature the oil damper.

Right?

For curiosity's sake, is it even possible to use an oil damper in vacuum? Would the oil boil off and coat everything? What would be a suitable fluid?
I'd vote for Beer. Its reclaimable and environmental-friendly  :o

Beer is good and consumable. Better yet don't waste it as a damper. Consume it while discussing how best to damp.

As for me I would have very tightly twisted the maggie power leads, keep the magnetic dampers and drank the beer.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline flux_capacitor

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Back from the Dresden front! Martin Tajmar sent me an email today where he says he measured the internal height of his frustum. It seems he went to the lab to measure it himself before his student came back from holidays ;)

Quote from: Martin Tajmar
I measured it: the internal height is 72.8 mm (after adjustment for better resonance). Between the Cavity and the waveguide we used an adapter. The measures are all correct. We simulated it in COMSOL and also Shawyer with his calculation program assured us that the dimensions we used were correct.

So the official internal dimensions from Tajmar are now:

Db = 108.2 mm
Ds = 77 mm
Height = 72.8 mm

Can you guys verify this cavity resonates in your frustumator software? :)

EDIT: A WR340 waveguide measures 86.36 x 43.18 mm so Tajmar used a coupling adapter reducing the waveguide.
« Last Edit: 08/03/2015 08:55 PM by flux_capacitor »

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