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Cavitation plasma induction impulse drive

Tiny engine which produces plasma by ultrasound and electromagnetic induction
  [vote for,

A microscopic spacecraft contains a liquid-filled chamber closed to the vacuum through a valved pore. The walls of the chamber can be "twanged" piezoelectrically, producing a shock wave. This shock wave compresses and rarefies the liquid, forming a cavity which then collapses, leading to ionisation and the conversion of the liquid to a plasma. The pore is opened immediately after this and a wave of electromagnetic induction is passed along the chamber, expelling it at considerable velocity. The spacecraft is pushed forward.

All of this occurs in a spacecraft whose largest dimension is less than a hundred microns, but forms a swarm with other spacecraft.

nineteenthly, Aug 31 2011


       This is definitely cool, but I'm just wondering about the shape of the chamber. I know a sphere would work for the compression, but not the exhaustion. A cylinder is the natural for the exhaust but not the compression. Maybe a sphere with a cone exhaust? Or a portion 1/8th to a 1/2 of a sphere and the pore at the center?   

       PS Did you ever read about the guys who were doing this to create fusion?   

MisterQED, Aug 31 2011

       No i didn't, that sounds interesting but insufficient. Shape, hmm. Would a short enough pulse of current act as induction in these circumstances?
nineteenthly, Aug 31 2011

       // "twanged" piezoelectrically, producing a shock wave. This shock wave compresses and rarefies the liquid, forming a cavity which then collapses, leading to ionisation and the conversion of the liquid to a plasma.// But does it?
MaxwellBuchanan, Aug 31 2011

       your craft will run out of fuel very, very quickly.
Voice, Sep 01 2011

       Well, [MB], mantis shrimp can generate plasma by cavitation, so if this doesn't work i strongly suspect there's another way of getting it to work on this scale with similar equipment.   

       [Voice], yes indeed but there are several answers to that. One is that this is one droplet of liquid and more could be provided, another is that it could still accelerate it up to the velocity required - i envisage this happening in interplanetary space, far from any large masses, and a third is that there is such a thing as the pressure of sunlight.
nineteenthly, Sep 01 2011

       Taews glands more like. These are not going to cool things down.
nineteenthly, Sep 02 2011

       Don't. I was put off bread for ages by that talking loaf with the eyes.
nineteenthly, Sep 02 2011

       //your craft will run out of fuel very, very quickly.// Any particular reason why?   

       My guess is that [nineteenthly] intends to harness the energy out there (wheresoever "there" is) for a fuel-less drive. The energy harnessed would provide the mechanism to generate the cavitation. No fluid actually being used as fuel. The geometry of the object would induce a direction of force. Look Ma, no hands!   

       I guess the hard part is the geometry of the object. But considering that the pioneer anamoly is thought to be created by the geometry of the craft inducing resultant forces in a particular vector, it can't be far from the truth.
4whom, Sep 05 2011

       // My guess is that [nineteenthly] intends to harness the energy out there (wheresoever "there" is) for a fuel-less drive //   

       That's another idea i'm working on now, to do with harvesting antimatter, but that's not for here and in fact there is fuel. No, my thought was to have a reservoir of powder which was then melted in the chamber one particle at a time.
nineteenthly, Sep 05 2011

       Here me out [nine...]. There was a proposition a few years ago, for an M-drive (IIRC). Basically, a cavity magnetron with a certain geometry, similar to a cone, or more acurately, the area described by some conic section. The developer claimed to have achieved a fuel-less drive. Obviously this was greeted with the contempt it did'nt deserve. Quite recently, researchers investigating the pioneer anomaly found that the geometry presented (all things considered) a similar geometry. Low and behold when you plug the numbers in you can describe the acceleration observed.   

       It must be said that the above anamoly accounts for solar winds, etc, yet still exists. However the accounting for more accurate measurement can never be, uhh, taken into account. Nor can the non-accounting of unknown unknowns. However it does suggest that certain geometries can produce resultant forces that at first seem to violate Newton's Second. At least for the mean time.   

       Fuel-less drives are a reality. Quite how we can master them, or if we can, is still a matter of some debate.
4whom, Sep 05 2011

       Clearly there can in a sense be fuelless drives, for instance there are, i think, monorails which use magnetohydrodynamic propulsion, but they still have an energy input. Hmm, i don't know, but i very much want to find out. I presume you don't mean something over-unity?
nineteenthly, Sep 05 2011

       Yes, of course they have an energy input, but they carry no fuel. No-one wants a free ride, (ie not over unity) but you don't need to use fuel in the vehicle in space, you want to use available energy. You would also like to use minimal surface material. Surface material being the materials garnered from your planet of origin. Therefore the use of cavitation may be more appropriate than a 1km^2 solar sail, for example.   

       Now, I am presuming a few things. Firstly, the examination of the pioneer anomaly, as mentioned earlier, is correct. Secondly, the anomaly produced is more efficient than using solar wind, or other. Both of these are untested but the possibility exists that they are true, or at least one of them is true.   

       I am not looking for over-unity. But fuel-less drives are very interesting. More specifically, fuel-less drives not using energy from our sun are very interesting. By creating a mini-sun (plasma spheriod) inside a working medium you can maybe create a resultant force, (obviously the jury is still out on this) without the use of onboard fuel. How do we create the energy to create this cavitation. Why, by harnessing the power of the sun, or suns, etc.   

       I find this interesting because it uses a minimal amount of earth based materials to replicate an effect that uses a lot of earth sourced materials. Not because it is magick.
4whom, Sep 05 2011

       //There was a proposition a few years ago, for an M-drive//   

       And it was bollocks.   

       //Fuel-less drives are a reality.//   

       No, they're not.
BunsenHoneydew, Sep 05 2011

       Well, in a sense fuel-less motors are a reality, if by motor you mean "physical device for achieving movement of a vehicle" and by fuel you mean "substance contained within said device", because then a sail would be an example, solar or otherwise.
nineteenthly, Sep 05 2011

       [Bunsen..] in your own words explain, including usage of onboard fuel:   

       1. The pioneer anomaly.
2. Orbits. (We have to presume they are burning fuel, in your world)
3. Solar sails.
4. Acceleration of galaxies away from any chosen point in the universe.
5. Newton's spinning bucket.
Bear in mind I said nothing of "reactionless" drives. Granted: the M-drive may be contrived bollocks, as first advertised. I maintain that the principles of cavitation may be included as a power source as a solar sail would be employed, given the correct construction of the device.
4whom, Sep 05 2011


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