Gas Compression With No Moving Parts

Scramjet has one moving part, the vehicle.

David A. Smith

The application I have in mind is static, moving gas from a low pressure system to a high pressure one. This is not a "low delta_p - high flow" nor a "high delta_p - low flow" but somewhere inbetween, closer to the latter. I am thinking of a standing-wave accoustic tube with some kind of one-direction flow devices (Tesla valves) placed at velocity nodes. Any other suggestions?

Violates conservation of energy, unless the gas is moving fast enough. (Bernoulli)

Doesn't help. How did you get the gas to move in the first place?

Moving parts.

Ionize the gas, and use magnetohydrodynamics to compress the stream before it recombines and you lose your grip on the stream. Don't know what you'd make the containment vessel out of, unless you have really low pressures both before and after (like sub-1-Torr).

David A. Smith

Of course there has to be external energy input, not trying to break any laws of physics.

Not necessarily, it can be a thermo-accoustic heat engine, but I am ok with a vibrating membrane and linear motor if it can run maintenance free for 10+ years.

I am trying to figure out if it's possible to build a refrigeration system that is very close to a typical vapor compression system in terms of refrigerating capacity, energy efficiency and overall size but has close to zero moving parts (no friction, seals, bearings, lubrication) and can run virtually maintenance free. This mainly targets the motors, compressors and pumps. The cost is also a factor of course.

Dear Tomy M:

On Nov 22, 8:55=A0pm, Tony M wrote: ...

Ah. That *has* been done:

The good old ammonia absorption cycle. I was looking into this a while back to be powered with solar heat. Way too inefficient to be cost- effective (COP 0.5 vs 3.2 for a commercial vapor compression system) but it works if you don't have another choice, or got loads of free waste heat available.