Thermoacoustics.

[FuzzyOnDetails]

I have been lampworking borosilicate glass for a living for over sixteen years. Every once in a while I have a piece of glass start "singing", sometimes quite loudly. Eventually, I learned this is an example of what are called Sondhauss oscillations. And so I was exposed to the topic.

The most commercially viable application of this emerging technology is refrigeration. Regular vapour compression refrigeration is compressing a gas, letting it dissipate the heat, and then decompressing it, allowing it to absorb heat. A sound wave is just a fluctuating pressure wave, so it too has the ability to pump heat, with no moving parts other than the sound wave itself. Sounds cool? (forgive me) Praxair is doing it to liquify natural gas. Ben and Jerry's use it to make ice cream. Liquifying oxygen, nitrogen, and other cryogenic liquids. The list goes on.

If you are looking to learn more, here is a good place to start:

http://www.lanl.gov/thermoacoustics/

If you are looking for the world leaders in this technology, I would say it is these folks:

http://www.qdrive.com/

[kimmy]

Thanks, this seems interesting. I will read more!

-k

[Bonam]

Looks pretty interesting, I'll read through it as well. Do you know if it can be used to liquefy helium (4.2 K)?

[FuzzyOnDetails]

Looks pretty interesting, I'll read through it as well. Do you know if it can be used to liquefy helium (4.2 K)?

Not currently, but it can be the first of a two stage refrigeration setup, instead of needing a four stage cascade system.