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EMdrive tested.

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dex

Sat May 04 2013, 07:40AM

Registered Member #2566 Joined: Wed Dec 23 2009, 05:52PM
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Chinese team say it works!

Conundrum

Sun May 05 2013, 11:08PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
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Posts: 4062

Really?
I'd like to see the test data, and if anyone wants to experiment in this area in my box o'junk is a microwave front end from a 2.2 GHz 2G transponder good for several tens of Watts.
Needs heatsinks and driver etc but the transistors all look OK.

Also have the PCB from an inverter microwave here.

-A

dex

Mon May 06 2013, 08:36AM

Registered Member #2566 Joined: Wed Dec 23 2009, 05:52PM
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Posts: 147

Conundrum wrote ...

Really?
I'd like to see the test data, and if anyone wants to experiment in this area in my box o'junk is a microwave front end from a 2.2 GHz 2G transponder good for several tens of Watts.
Needs heatsinks and driver etc but the transistors all look OK.

Also have the PCB from an inverter microwave here.

-A

on the provided page you have the link to their paper :

the concept seems crazy but measured max thrust of 0.72-0.75 N with 2.5 kw magnetron is clearly a noticable thing.dr.yang juan claims they eliminated various other possibilities that can be suspected in to give measured results .yes,it doesn't look like complicated machine and can be made at home.magnetron is easy to get from microwave oven.the bucket has to be of right geometry though.

Conundrum

Tue May 07 2013, 05:06AM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
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Posts: 4062

Yes, it also has to be run at resonance much like a Tesla Coil to ensure that a standing wave is generated or there is no thrust.

This would seem to be similar to a rocket engine's combustion chamber, if I understand correctly.
In fact, RF excitation of burning fuel has been theorised as a way to "juice up" a conventional rocket engine so the Isp is higher for the same fuel.

-A

dex

Tue May 07 2013, 11:46AM

Registered Member #2566 Joined: Wed Dec 23 2009, 05:52PM
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definitely,it's not similar to a rocket engine!that's the whole point.
looks like it violates the law of conservation of momentum (fundamental law of physics).

Mattski

Tue May 07 2013, 05:32PM

Registered Member #1792 Joined: Fri Oct 31 2008, 08:12PM
Location: University of California
Posts: 527

wrote ...
.dr.yang juan claims they eliminated various other possibilities that can be suspected in to give measured results

I'm sure he did claim that.

In reality it can be very tricky to perform accurate measurements in a sensitive setup. I know I've definitely performed measurements that were repeatable, tracked the stimulus level, and had a high signal to noise ratio, which turned out to be completely wrong due to unintentional coupling in the system which drowned out the actual signal. Accurately measuring tiny force in a system with 100-2.5kW RF power levels with the "thruster" mechanically connected through a waveguide sounds challenging.

Long story short: Don't believe everything you read online, especially when the results contradict accepted physics. Because the chances of physics being wrong is less than chances a researcher making a mistake or intentionally misrepresenting the results.

As always with stuff like this I'm happy to be proven wrong but so far I don't buy it =)

dex

Tue May 07 2013, 08:22PM

Registered Member #2566 Joined: Wed Dec 23 2009, 05:52PM
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Posts: 147

juan is she

Conundrum

Thu May 09 2013, 04:02PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

Surely an effective way to measure thrust from such a setup would be to mount an accelerometer, battery and datalogger in a double shielded box grounded to the case.
If there was any effect then the accelerometer would show a clear unambiguous acceleration only when the system was in resonance, even if the rotation was very slow indeed.

EDIT:

1983, microwave resonant chamber with strong magnetic field. Sound familiar?

I suggest that EmDrive does actually work, by converting normally undetectable solar axions into kinetic energy.
Can someone prove this can't work because if not I might be onto something here.

If this is indeed correct then a superconducting chamber might not work as expected because it would by definition exclude magnetic fields from its interior thus quenching the effect.

EDIT: Assuming MiHsC is correct (ie modified inertia) then this becomes a way to test the hypothesis.
So if it doesen't work as expected or the thrust drops when the superconductor is below Tc then
useful science can be done.

I've designed a simple setup involving superconducting plates and wire but the cost is horrendous.
Reckon if it went on Kickstarter people would just laugh?
This is using the highest possible Tc variant of Y123 doped with rare earths and lead.

Pyrolytic graphite doped with lead *might* work, as charge density waves have been observed as of August 2014 and I've seen evidence first hand that it can superconduct at 281K which if confirmed would be unprecedented.
It indeed it is a Type III (ie bipolaron, pairs of electrons/holes) then this could explain the high Tc and other previous observations by Profs Prins and Pablo.

-A

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