This is about Rangue Vortex Tubes. See first link: http://www.visi.com/~darus/hilsch/ You can google for VORTEX TUBE COOLING and find many industrial applications.
a. It "turns" out that an ultrasonic wave is what makes the Rangue (Hilsch) vortex tube work... See 2nd link. http://www.amasci.com/wirbel.txt
I propose to try and make this sound with a slow moving vortex air column, and possibly receive simmilar results (hot air vs. cold air sepparation.
I hearby propose another series of experiments which would be very nice to try:
b. Creating a "no extra input tube" vortex: as follows - Air enters from periferal of "cold side" is fanned to a double (fast and slow) vortex, hot air leaves peripheral of other side and cold air extracted from this (cold) side. b. same as (a) only no parts in tube, only external fan (or suction caused by natural air flow) pulling air at hot side, and blades or openings at tubes end giving the air flow in the tube its vortex shape. A fan in middle of cold side extracts the cold air column (or perhaps a large fan on cold side with fins only near the tube fuselage PUSHING the incoming air and outgoing cold air flowing freely with tube elswhere (so doesn't re-enter tube). c. letting in humid air or even water spray into regualr vortex tube. d. Making miniature (mm and less) vortex tubes, which could work with lower pressures (less volume needed to reach effect) and thus applied in arrays, could become the next air conditioning unit. (no moving parts, no gas, possibly no electricity! (run by hot winds?)-- pashute, Aug 19 2003 vortex cooling tube explained http://www.visi.com/~darus/hilsch/google for the industrial units [pashute, Oct 04 2004, last modified Oct 21 2004] ultrasonic wave is what makes this phenominon http://www.amasci.com/wirbel.txttxt file but well explained [pashute, Oct 04 2004, last modified Oct 21 2004] random, halfbakery