Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2099025 times)

Offline Cinder

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The point there being, AIUI, that you can't develop those compelling theories under an "ignore the theory" MO; and that a thread excluding that approach would necessarily cause friction: minor friction in individuals exercising that discipline and major friction for moderators exercising it for those who won't.
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Online Rodal

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 "There is NO accepted theory" doesn't justify "Follow the Data. Ignore the theory".  On the contrary.

Although I have been personally involved in experiments all my life,  I am not familiar with anybody following that approach (Ignore any theories) at Universities or private R&D companies. 

I think it may be an exaggeration to overemphasize a point, as we all tend to do.  Nobody conducts completely random experiments in the hopes of trying to find a new physical result by pure lack.  Unexpected results many times turn out, that later have to be explained, but that is different from conducting completely random experiments on purpose. 

There is nothing wrong with "Follow the data".   The wrong part is "Ignore the theory" if by ignoring the theory means abandoning all human knowledge.

I think that what was probably meant should have been "Ignore a particular theory that is contradicted by the data"

All fundamental R&D at leading institutions deals with problems in which there is "no accepted theory" of course. That is what fundamental research means.

If there would be a single, universally accepted theory, with experimental verification at multiple research locations, then it would not be fundamental research  :).

CERN does not use the approach "Follow the Data. Ignore the theory".  :)
« Last Edit: 05/07/2015 04:35 PM by Rodal »

Offline Mulletron

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The point I'm making is this. You see these men sitting at the table together in this video? They're all on the same team....trying to figure out how to pull off interstellar flight. For the good of all of us. Now they're duking it out in an interview in Wired. They (like us) should all be working together, pooling resources, combined knowledge and experience. Instead a rift has formed, which will likely kill progress.

I do not want that to happen to this thread, which mas made pretty darn good progress so far. Not bad for a once unknown internet forum. Now back to work.

« Last Edit: 05/07/2015 02:19 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Flyby

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Dr. Rodal,
with all respect , but I do tend to follow Mulletron in this.
Due to the absence of THE theory, there are several theories and solutions being discussed at once. Agreed , that causes some confusion, certainly for a layman like me, but at the same time, it makes it interesting and easier to compare the ideas.

Is your irritation not more due to the fact that these interesting theoretical discussions are crosscut by the pragmatic talk of those ppl who are build test setups?

If there would be any split up needed then, i would suggest to split the engineering part of the home builders apart from the pure theoretical/mathematical discussions.
But in all honesty, that would be regrettable, because it would make cross-fertilization harder (fe, like the radial wire mesh you've found in those theoretical papers)

I don't think anyone's ignoring the theory (or should be).  It's just that data is a lot easier to produce than theory, and a couple of the builders have been particularly active lately.

I'd like to hear more about WarpTech's theory about momentum transfer once the resonant waves reach their break-off limit.  He compares it to an event horizon, though perhaps not in the physical sense.  I'm not clear on that or exactly how the transfer would occur.  Also, why, if there is an event due to the physical constraints of the waveguide, would it necessarily be a momentum transfer rather than a heat transfer?

Thank you.
« Last Edit: 05/07/2015 02:35 PM by lasoi »

Offline Iulian Berca

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Hello, I`m new in this forum.

I read almost all the papers that can be found on Emdrive.com website and a part of this thread, and think is not so difficult to replicate the EMdrive.

I have electrical engineering studies, i build some brushless motor for electric cars and scooters,  motor controllers (inverters), lifters in the past, and other thinks.

As i noticed, Juan Yang professor from Xian Northwestern University China, had the best trust results.

I have some questions about building the emdrive.

I can not find the exact dimensions for her drive. Maybe you can help me with them.

1. It is possible to use a microwave oven magnetron and  assume that i will still produce trust?
If yes :
2. Can i just make a hole to the cone and put the antenna of the magnetron inside like in the attachment.
The wave guide has other purpose than feed microwaves to the resonance chamber ?
I will make the cone length to be adjustable (+/- 2cm) to be able to tune the of the resonator cavity for around 2,45Ghz frequency.

The power will be adjustable from ~ 200W- 800W . I`m not sure if i also need to decrease the current to the filament.
I will build myself the voltage regulator or i will just use an AutoTransformer to adjust the input power.
The cone material will be cooper 0.6m thikness.

I will try with different materials on the both ends of the cone. ( bare Cooper, HDPP, PCB, metaglas, and any other materials you may suggest).
I will post all the construction progress and the results, after i receive all the materials, in a couple of days.

Iulian


« Last Edit: 05/07/2015 02:46 PM by Iulian Berca »

Offline TheTraveller

"Follow the data, theory be dammed!"

As stated by Paul March:
http://forum.nasaspaceflight.com/index.php?topic=36313.msg1356062#msg1356062

Quote
Dr. Rodal:

As promised, find attached a few related papers from work.  As to the rest of your and Mulletron's concerns over the Eagleworks evolving theoretical musings on the EM-Drive propulsion topic, I leave you with Boyd Bushman's, (was senior scientist at LM/FW, now retired and passed-on), admonition to me when I first met him back in 2000 when discussing Jim Woodward's Mach-Effect work with Boyd's boss, "Follow the data, theory be dammed!"  We intend to do just that, no matter where it might take us.

Best,  Paul M.
« Last Edit: 05/07/2015 02:43 PM by TheTraveller »
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Offline D_Dom

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Feeling incapable of contributing much to the theoretical analysis I feel competent in building a device and providing accurate data. I have learned to think carefully before experiment/measurement so that I understand what is being measured, what the data is expected to reveal and why it is relevant. My point is both disciplined theoretical analysis and experimental data are useful.
« Last Edit: 05/07/2015 02:51 PM by D_Dom »
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Offline Blaine

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I'm new here and I just thought I would post this video for you all.  Its a very VERY sloppy experimental setup of something like the what people on this forum are talking about.  The interesting thing here is the man in the video doesn't use end-plates and its quite a bit slimmer than the EM Drive.  Here is the video:



What are some thoughts about the video posted?
Weird Science!

Online Rodal

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I'm new here and I just thought I would post this video for you all.  Its a very VERY sloppy experimental setup of something like the what people on this forum are talking about.  The interesting thing here is the man in the video doesn't use end-plates and its quite a bit slimmer than the EM Drive.  Here is the video:

youtube.com/watch?v=vcaOKX7Ko7w

What are some thoughts about the video posted?

Rough translation (From original in Russian):

Quote
Created Shawyer  (EM Drive) engine is very easy and simple in its design . It provides the necessary thrust " by the oscillation of the microwaves inside the vacuum container ."
http: //hi-news.ru/technology/v-nasa-i ...
I decided that the system should not be closed



It is a waveguide with one end open.  The Russian author points out (later in his Russian text) that he thinks that Shawyer, and others are wrong in using a closed cavity.

The reference (Cullen) given by Shawyer to support his theory also used in his experimental measurements of pressure, a cavity with one end open (with a transparent glass)


It is known that a microwave waveguide having one end open will display directional thrust, as the microwave photons escape the waveguide.  The problem with the EM Drive is that it is a closed cavity, hence it cannot be explained solely based on Maxwell's equations. Something else is needed: General Relativity, QV,  something else.

A waveguide with one end open will behave as a very inefficient photon rocket: thousands of times less thrust per power input than what is claimed in the EM Drive experiments.
« Last Edit: 05/07/2015 03:53 PM by Rodal »

Offline TheTraveller

Feeling incapable of contributing much to the theoretical analysis I feel competent in building a device and providing accurate data. I have learned to think carefully before experiment/measurement so that I understand what is being measured, what the data is expected to reveal and why it is relevant. My point is both disciplined theoretical analysis and experimental data are useful.
Glad to get another builder on board.

We all have different skill sets and look at the world through different eyes. Thus we ALL bring to the table, different skills, experience, risk tolerance, outlooks and desires, which when combined synergistically, will allow test and theory to go forward TOGETHER, based on respect for each others ability to contribute and think outside the square.

One thing I learned very early on in life:
"None of us is as smart as ALL of us".
« Last Edit: 05/07/2015 03:15 PM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
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Online Rodal

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Now, that's something we can all agree with  :)

Offline jknuble

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Following on what jknuble said about the multipactor-like effect as a possible cause of thrust. http://en.wikipedia.org/wiki/Multipactor_effect  I can't help but wonder about what's going on with the copper surface of the frustum. A quick back of the envelope (well, python) calculation shows that there's certainly enough energy in these devices to somehow atomize a small amount of copper , and propel them with enough momentum to produce a small amount of thrust.

For example, a 30 watt emdrive where 0.001% of the energy went towards atomization and 1% went toward addtional momentum of the particles... You'd have a device with 91uN thrust, propelling 1.4ng of copper a second at 65500m/s.

I can think of 3 ways to debunk this. 1) perhaps that amount of particles going that fast would be noticeable with the naked eye, so this isn't really a valid explanation. 2) stick a detector behind the thruster (are they ionized?). 3) SEM of the surface compared to scraps from the same batch of copper not used in the thrustum.

Just how would we get a net-thrust from a closed cavity with atomization.  Even if atoms are being ioniozed inside the cavity I don't see how that could result in a net thrust.  Atomization results in immediate thrust but then that creates impact on the other side of the cavity canceling out the propulsion.
I'm talking about signs of atomization on the *outside* surface of the frustum. Although it would probably be happening in the inside as well. The copper atoms would be the propellent. I'm not sure what the mechanism would be, but it's obviously more than a thermal effect, and the whole reversal in phase/thrust would be difficult to explain. It seems more simple than QV or relativity models, but it's still probably interesting physics.

It might also explain the interferometer results.


Hi Everyone,

Just checking in and reading through some comments.  Thanks for taking a look at the potential forces involved, rgreen. I believe a force from atomized particles on the interior could have similar - or stronger - effect than being generated on the exterior even if your design is properly vented in vacuum. Especially if the cavity was not designed to be hermetic but is not intentionally vented.  Think of a balloon with a pin-hole in it.  I did some searching and couldn't find the word "hermetic" or "vented" in the paper or discussions but perhaps the design is vented.  If it is designed to be hermetic I would suggest publishing the results of a fine and gross leak test as a hermetic design of this size with braised glass seals for the launch is non-trivial.  With a small leak you could have built a simple thruster.  The sensitivity of that leak test would need to be appropriate to catch a particle stream that equates to millionths-of-a-pound (more tangible units than "micronewtons" to me) of thrust.  This effect could occur in our out of vacuum. This is all speculation and hand-waving though as I don't know all the details of your assembly.  While I can't say the exact mechanism that would cause a force to occur, I think it is possible this force is present (sound familiar? :) ).   

Regardless, putting on my "NASA Independent Reviewer" hat, I would say that if you are claiming to have developed a technology which can provide propulsion without a propellant, you have a burden of proof to show that you are not self-generating your propellant due to RF energy interacting with the materials in your setup.  These materials could include your metals, coatings, adhesives, dielectrics and / or contaminants. I don't believe there is sufficient evidence from the test points over a range of power levels and in and out of vacuum and across test teams (US, China, Britain) to confirm or refute this as I can imagine situations where particle generating effects would occur in any case due to out-gassing, breakdown, corona, multipaction etc.  I am not involved in your effort at all so please forgive my intrusion but from an RF engineering perspective it would be great to see a paragraph in a paper someday explaining how you tested for these effects and can now dismiss them and that you havn't inadvertently built a conventional thruster or ion drive.  I saw an earlier post suggesting a wiki be developed which would include potential sources of error and this topic could be filed there.

I believe a good test would involve at least following (again, my apologies if these were done in part or seem obvious.. I am also repeating myself a bit here from earlier posts):

1 - Add sufficient vent holes to the RF cavity.  Ensure the hole diameter is small enough such that their wave-guide effects do not effect the S11 of the system in the range you're operating in.  It seems you do have an ability to do 3D e-mag simulations but here is a tool you can use to verify the venting does not have a significant electrical impact: http://multipactor.esa.int/features.html. Unless you have specifically designed the system to be hermetic with glass seals etc, it will slowly leak and confuse the test and possibly be the source of thrust.  Hopefully you are not currently relying on your antenna launch or fasteners on the cavity caps for venting.  Testing under vacuum is actually the best way to resolve this issue and is the "relevant space environment" (i.e. high TRL!) so hermetic designs should be avoided as this helps your case anyways.  The proposed physics don't require a gas to be present, correct?  To be clear, whether or not you are currently vented does not confirm or refute anything as I can envision scenarios where a force would be generated even with a properly vented design in normal atmosphere from the momentum imparted by the particles at the focused atomization point (millionths-of-a-pound!)... so this is just a first step.

2 - Ensure you perform an un-powered elevated temperature bake-out of the DUT and support electronics at 50 to 60C for least 24 hours under vacuum.  This is generally what we do for RF space-flight hardware as that is what is required to get most of the typical volatiles out of a system.  It looks like this was done for the chamber but the DUT does not appear to have been heated.  This needs to include any support electronics - in fact, move all but the bare minimum of electronics outside the chamber.  Completion of most out-gassing should be observed not with your vacuum pump monitor but with a TQCM in real-time (http://en.wikipedia.org/wiki/Quartz_crystal_microbalance).  Note- this bake-out is a pretty crucial step to eliminate the possibility of simple out-gassing being the culprit for this phenomenon.  Out-gassing can be a non-linear behavior in some materials.  Some materials out-gas at a rate proportional to their temperature.  Others will not begin out-gassing until they reach a certain temperature.  So the experimenter should perform an un-powered bake-out over the range of temperatures the *powered* system should expect to see.  So if you are dissipating 2.6W in your cavity a thermal analysis should be done to see what temperature the system (especially the launch) would get to in vacuum.  Alternatively just instrument it properly and run a test first.  A bake-out will need to be properly done prior to every test as re-exposure to atmosphere will re-coat the DUT with contaminants and your dielectric will absorb moisture.  A mistake we made on the Aquarius mission (http://aquarius.nasa.gov/) was not performing a high temperature bake-out with our heaters once we reached orbit.  Consequently it took weeks for the system to stabilize as the dielectrics out-gassed moisture and we could observe the dielectric constant of RF boards drifting.  In short, ensure the un-powered temperatures reach and exceed the temperatures caused by RF heating when operational at the test temperature.

[General note on the 2.6W case as it is often used for an argument against the causes I have listed:  Some have noted the 2.6W test is "low" but that is a huge amount of power for parts to handle in my field (RF radiometry). For example, consider that few of the passive parts sold by these folks can handle more than a watt or 10s of watts unless they are specially engineered for high power applications: http://www.minicircuits.com/  Consider what is actually occuring in the part when you reach the maximum power level and could that effect generate enough particles to create millionths-of-a-pound of pressure.  Also, in many components the limiting factor is the launch design.  Returning to your test setup, your PTFE insert will certainly heat and out-gas due due to a portion of the 2.6W of RF power being dissipated within it.  I note the slow time-constant on the plot in Figure 22 looks an awful lot like what you would see from a thermal effect, particularly as thrust slowly decays after RF power is removed:  http://arc.aiaa.org/doi/pdf/10.2514/6.2014-4029.  Also I interpret the setup as 2.6W being dissipated in chamber but with 28W incident from the power amps with the related electric field levels of 28W in your system.  This is my understanding based on this statement in Part B of http://arc.aiaa.org/doi/pdf/10.2514/6.2014-4029: " In this test configuration, the VNA system indicated a quality factor of ~7320, and the difference of power forward and power reflected as reported by the power meters was indicated to be ~16.92 watts as a result of manual tuning to maximize the power difference. " So for purposes of thermal effects, 2.6W is correct.  But for breakdown effects, the electric field strength associated with 28W is what should be considered, simulated and evaluated against breakdown.]

3 - Once the system is stabilized, I would turn on the RF power transmitting into an RF coaxial short rather than a load, perhaps with an RF switch. A full reflection which is a worst-case in your system could cause issues on your source and induce some out-gassing or breakdown from that device.  Ensure the TQCM does not detect anything. This will let you know if your setup would cause a false-negative for the test I'm proposing. Generally, ensure you have brought on an experienced materials or contamination engineer to set this test up for you. Also this would serve as further proof there are not a conducted or radiated interference issue.  The paper notes the DC currents from the power amps do effect the measurement to a degree so this case is more similar to what the amps are actually driving just to be thorough. 

4 - Turn on your system in the normal test setup and observe the TQCM.  If particles are detected you may have found the culprit as these may be the result of out-gassing, breakdown, corona, multipaction, etc.  These effects all generate particles and correspond to different power levels and environments. This step can be tricky but I've seen it work well when experienced people are involved.  When you have pulled a vacuum, small particle generation detection is more reliant on Brownian motion etc. to cause particles to exit the vent holes and get to the detector so some care is required here.  As I mentioned in an earlier comment this was the method used to verify that multipaction was occuring within the SMAP diplexers and not a purely reactive effect.

5- Allow the system to run for at least a week to ensure the force does not dissipate or change due to a propellant being expended.  Also, if possible, increase the sampling rate of your force sensor to be faster than what one would see from thermal effects.  I'm not at all familiar with the proposed physics to explain the phenomenon but generally a purely RF cause should result in "instantaneous" force.  Faster than milliseconds should be enough to discount thermal effects although not all the sources of error I have mentioned are thermal.   

6 - (Mentioned this previously) - Open the cavity and have someone experienced inspect the materials for any evidence of breakdown.  A detailed inspection and cleaning should be done before the unit is sealed if that is possible.

So hopefully some of this is helpful.  Someone else may be able to devise a more compelling test for the hypothesis. In summary, there are a variety of particle generating effects of high RF power including out-gassing, corona breakdown, multipaction, plasmas, etc.  Each can occur at different power levels, some will occur in vacuum, some not.  It is possible each of the teams is seeing one or more of these effects depending on these variables during any given test.   The above statements are general and also apply to the tests done by the Chinese and British teams and any future test.  So while "multipaction" may not be the current culprit with the setup at 28W it could be as testing is done at higher power levels.  I have focused much of the above discussion on the small 28W case in the referenced paper but KW of RF energy are known to cause somewhat violent events including (but not always) magic smoke and burned components.  So generating a newton of force during these events seems conceivable.

I dug around online for resources related to high power breakdown at RF frequencies and couldn't find much.  Here are a few things but these may a bit too basic.

http://en.wikipedia.org/wiki/Electrical_breakdown

http://www.microwaves101.com/encyclopedias/power-handling

Helpful tool:

http://multipactor.esa.int/

I hope this post wasn't too rambling or too full of misconceptions regarding the tests you have performed.  I don't envy you folks trying to make progress on this complex issue via a public internet forum. Good luck, and again, I hope I'm wrong!

-Joseph Knuble,
NASA GSFC Code 555
Microwave Instrument Technology Branch

Final note for any students here who are curious about RF: This is far below the power levels I believe you have operated at but for future consideration at the 100W to KW level note the acoustic (i.e. pressure) effects of this demonstration which uses a 2.4GHz magnetron in a closed cavity with a contaminant:   Depending on the dynamics involved, teams which have tested at high power could be seeing the effects of a similar unstable vibration (think of your vibrating cell-phone skittering across the table.)

Offline CW

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I think that the solution is really simple, if it's about demonstrating a thrust effect that is many times larger than measurement precision: Crank up the RF power. A lot. There is really no two ways about it. Please don't even try to play with a power level that even a 9V-battery can put out.. . Personally, I'd play in a power regime of about 1kW (actually I do, but that's another story..) . 1KW is a level that can easily be handled by readily available parts and off-the-shelf electronics, but is still not excessive.
Which battery types would you recommend for 1 KW operation?

I personally use LiFePO4 batteries, as they are inherently safer than alternatives. For instance, I have one (about 1kg) with 8400mAh capacity and 30C continuous discharge capability (252 amps). You can extract ~1kW for a couple minutes, which should be enough for measurements. Recharging is also fast.
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Online SeeShells

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Now, that's something we can all agree with  :)

I second that statement! You know I have some old wire mesh (old front door screen) to build a cone shaped can, connect some wires to an old and discarded microwave, power it and Bingo, Warp Drive! It's not that simple and what if I, by the shot in the dark make something that does work better than anything out there? I've accomplished very little as the other part of the equation of why, isn't there. Theory, Design, Engineering and Testing all go hand in hand. One aspect may leapfrog another during a process.
I have no solid clue why this EM drive works, sure there are some great theories (some of them have "warped" my little brain) out there. I have no doubt a answer will make itself known by Developing Theories, Designing, Building, Testing in synergy.

Online Rodal

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I will post here the solution for a very simple set-up of a cube cavity maintaining a single mode and show the way the laser beam propagates inside it. This resonant cavity seems to be very good for engineering of space-time rather than else.

May I respectfully ask that you also include a visualization of the solution if possible?  I'd very much like to see this.
StrongGR  may be talking about a closed-form solution for that case (without the dielectric insert), therefore a mathematical formula.  Not necessarily including plots, as they are necessary for numerical solutions. 

Given the closed-form solution (for which we would be most thankful  :) ) then all of us could make plots using our own software, for any numerical values we are interested in.

That's why closed-form solutions rock :)

Correct, I am providing some closed form equations for a simplified case that should describe correctly what observed recently at Eagleworks. As said before, I cannot find an explanation for thrust in the framework of general relativity. In the aforementioned Minotti's paper it is shown that one needs to modify the theory to account for it. Minotti's paper can be helpful to discuss the full problem and this will be work for the (very) near future. The point that I would like to understand is if the linearized Einstein theory could be enough. Probably so but my analysis for the simplified problem makes me think that a cavity can yield more for a laser propagating inside.

Eagleworks' results about the laser and the cavity are exciting because could pave the way both to table-top experiments in general relativity and space-time engineering as the technology to manage electromagnetic fields is well acquired.

Feel free to comment on this first draft.

What an original contribution !

this is very interesting:

Quote from: Marco Frasca
One sees that there is an additional component to the laser field exiting the cavity that interacts with the mode inside. This can have terms with the frequency shifted and is a purely gravitational effect.

This result is extremely interesting. 

Quote from: Marco Frasca
I have shown how a plane wave could produce a gravitational effect inside a cavity that could be observed using a propagating laser beam inside it. The effect could be unveiled using an interferometer or observing the components of the laser field outside the cavity. Components with a shifted frequency, due to the modes inside the cavity, should be seen. This could explain recent results at Eagleworks with a resonator having the form of a truncated cone. A local warp of the geometry due to the electromagnetic field pumped inside the cavity could be a satisfactory explanation

This justifies Dr. White's attempts to measure these effects with an interferometer



I'm looking forward to your attempt at dealing with a truncated cone geometry (difficult geometry to analyze)
« Last Edit: 05/07/2015 05:03 PM by Rodal »

Offline TheTraveller

I hope this post wasn't too rambling or too full of misconceptions regarding the tests you have performed.  I don't envy you folks trying to make progress on this complex issue via a public internet forum. Good luck, and again, I hope I'm wrong!

-Joseph Knuble,
NASA GSFC Code 555
Microwave Instrument Technology Branch

Final note for any students here who are curious about RF: This is far below the power levels I believe you have operated at but for future consideration at the 100W to KW level note the acoustic (i.e. pressure) effects of this demonstration which uses a 2.4GHz magnetron in a closed cavity with a contaminant:   Depending on the dynamics involved, teams which have tested at high power could be seeing the effects of a similar unstable vibration (think of your vibrating cell-phone skittering across the table.)
Appreciate your post. Food for thought.

Do have concerns about gaseous venting from inside my heated cavity, Plan to have a very fine hole in the centre of the small and large end plates, which can be block if so desired. As in both ends, any venting should counter balance. Being able to block or not either or both will generate additional experimental data sets.

Seeing that Shawyer used vertical cavity orientation and balanced Teeter Totter beams says to me he knew of the issues and took steps to avoid them. Which encourages me his thrust data is real and I can replicate it.

BTW I'm not using a magnetron as my RF source but instead using a variable frequency narrow band RF generator (1kHz steps) and a solid state RF amplifier, so no vibrational noise generation issue. Biggest noise generator would be the fan on my laptop.
« Last Edit: 05/07/2015 04:02 PM by TheTraveller »
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Offline WarpTech

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The point I'm making is this. You see these men sitting at the table together in this video? They're all on the same team....trying to figure out how to pull off interstellar flight. For the good of all of us. Now they're duking it out in an interview in Wired. They (like us) should all be working together, pooling resources, combined knowledge and experience. Instead a rift has formed, which will likely kill progress.

I do not want that to happen to this thread, which mas made pretty darn good progress so far. Not bad for a once unknown internet forum. Now back to work.




Starship Congress 2015 was just announced. I hope to be there this time!

https://www.eventbrite.com/e/starship-congress-2015-interstellar-hackathon-tickets-16813758404?aff=efblike&fb_ref=Default


Offline TheTraveller

Quote from: TheTraveller
Plan is to replicate the Flight Thruster using 100Ws of RF during the static tests. At 150W, Shawyer got around 40mN or 4gf of thrust, which would give me around 25mN or 2.5gf. As my setup will be much lighter than Shawyers rotary system and will be using magnetic bearings, 2.5gf should be more than enough thrust to run load versus power consumed tests and generate a descent curve to show COE is obeyed or not.
I imagine the chief source of friction will be the generator bearings. Or can these also be magnetic?
Generator frictional losses will be significant. Scrap that idea.

Thought is now to add mass to both sides of the rotary test rig, so to incrementally increase the acceleratory mass load on the EM Drive, which should have the same effect as putting increased loads on the system.

I'm also thinking about a counter balanced weight pulley system which keeps the test cavity in the same orientation as the static test rig and allows the test article to move up or down from thrust generation. More KISS than a fully rotary test rig.

Pity I can't use the "knife edge" bearings of the Teeter Totter balance system.

This is interesting, yes I know it still has one point of frictional contact but I'm sure I could get it to work for the rotary test rig and for the pulley based test rig. Stiction would be VERY low:

« Last Edit: 05/07/2015 04:45 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 saucyjack

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The EM Drive wiki project is starting to take shape - thanks in particular to @MazonDel who has begun adding and organizing content, including links back to the relevant posts and attachments on this forum and elsewhere.  It's still very early, so any assistance is greatly appreciated!  The site is run on MediaWiki (the same software used by Wikipedia) so it's quite easy to jump in and start contributing.

For those building their own test articles, I invite you to update this page with your plans and links to any relevant photos, diagrams, videos, etc.  We also have sections to list out the various theory proposals, possible error sources and a placeholder FAQ.

@Chris Bergin, feel free to link to this from the forums, when and if you think it would be of value to your visitors (particularly the newer ones).

-Rolf

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