Ranque-Hilsch Vortex Tube (Interactive Simulation)

Organized by textbook: learncheme.com/ Demonstrates how to use the interactive simulation that models a Ranque-Hilsch tube, which splits high-pressure air into hot and cold air at lower pressure. The simulation is located at httpss://www.learncheme.com/simulations/thermodynamics/thermo-1/ranque-hilsch-vortex-tube . Made by faculty at the University of Colorado Boulder, Department of Chemical & Biological Engineering.

[@jboone8561]

Yep we use these at work to cool off slitting saws when machining material we can't use coolant on.

[@basheermigdadi3375]

what is the tube length? cold and hot orifice diameters?

[@kreynolds1123]

How does length and diameter of tube effect performance?
Also, I'm wondering if liquid cooling on the tube's outside exterior can drop the cold side temp further, or would that just cool the hot side exhaust without impacting the cold side much?

[@timh.6872]

Cooling the exterior might help to some degree, as the cooling of the inner vortex is caused by the outer vortex "stealing" energy to stay at the outside. Or perhaps the inner vortex is pushing energy into the outer gas because it has a tighter radius. Either way, it's energy transfer towards the outer vertex. If we pull energy away from that outer vortex by keeping it cool, then we should see a drop in temperature at both ends, a larger feed fraction at the cold end, or perhaps a reduction in tube length, as the energy needed to keep the outer vortex spinning is increased.

[@kreynolds1123]

@@timh.6872 I see that in theory, a larger diameter and longer tube will have more surface area to give up its extra heat, maybe increasing the COP. Furthermore, actively cooling the outside of the tube will cool the cold side gasses. But, active cooling the outside is another issue. Either way, we don't see really long huge tubes for some reason.
Maybe there's more friction with the wall, or more time for friction between the inner and outer vortex. Or maybe other factors.
I think the inlet gas stream is a gas of molecules with various velocities. I think that as it vortexes, the faster higher energy molecules tend to the outside while the slower ones tend to the inside.

[@timh.6872]

@@kreynolds1123 I did far too much research on this last night. The consensus, currently, on how it works is that the two vorticies trade energy from inner to outer, essentially making a simultaneous compressor and expander. This only works if the vorticies are distinct, so making the tube even longer might break the clean biaxial flow we need for it to work.
It's also general consensus that this only works at high pressure differences, 1.9:1 inlet to outlet or better, as there are supersonic effects at play in the swirl chamber.
However, I did come across a paper that seemed to show significant cooling at much lower pressure ratios, so I'm not completely convinced that a low-pressure "temperature separator" vortex tube is impossible

[@kreynolds1123]

@@timh.6872 I had almost forgotten this. Now I want to know 😉 Too bad, I have 100 other projects vying for my time and not enough money for each. 😎

[@oadka]

Ah, the coefficient of performance is very low, only 0.15. Air conditioners usually have more than 2 while refrigerators are even better with CoP greater than 10.

[@de0509]

Nope. Still sounds like black magic to me...

[@azemali231]

any chance of visiting Frank and this production unit, I live in Germany and willing and able to visit and first of thank you for such a visionary invention, my work involves Victor S, Wilhelm R and the like os Tesla, who were all god Fearing men!. and only copied natur, Frank thank you.

[@InservioLetum]

*despite being fantasy-fearing men

[@ryarbrough1195]

... ... ... to whom are you speaking? ... .. .

[@1.4142]

Marble run