| Chronology | Current Month | Current Thread | Current Date |
| [Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
DS: This will not be very helpful but possibly interesting. When I was a high school teacher in 1960, one of my students built a set of such devices and did some rudimentary experiments as a class project. He actually got some pretty amazing temperature differences. I, too, looked for explanations that I could (a) understand and (b) believe. I gave up too soon to keep this from remaining the empty set. I'm sure I have long since lost all my material on this topic.
It may help your search if you know that back then I think these things were called Hilsche tubes rather than R-H tubes.
Howard Voss
----------
From: David Strasburger-fac
Reply To: phys-l@lists.nau.edu: Forum for Physics Educators
Sent: Monday, April 24, 2000 1:06 PM
To: PHYS-L@lists.nau.edu
Subject: Ranque-Hilsche Vortex tube
Can anyone recommend any good references on the Ranque-Hilsch Vortex tube?
I have a very dedicated and resourceful student (high school senior) who
wants to build one (his idea, not mine.) We have looked together for
references but not turned up much that was helpful.
Most references we found were fairly vague as to construction details.
There is, apparently, a good reference in the Amateur Scientist column in
the November 1958 issue of Scientific American, but we're still working on
getting our hands on a copy.
I would also like to hear it if anyone had a good way of explaining how
this thing works. The descriptions I have read have been fairly
hand-wavy. Not that I could probably understand a highly technical
explanation -- my grasp of fluid dynamics is pretty elementary. Even so,
this is a pretty remarkable-sounding device and I'd love to have a better
understanding of what makes it work.
I am guessing that many readers are not familiar with the Ranque-Hilsche
Vortex tube. (When my student asked me about it I had no idea what he was
talking about....) Here is a rough description: compressed air enters a
small round chamber along a tangential path, creating a vortex inside the
chamber. Two tubes leave the chamber along the axis of the vortex. The
air that exits one tube is cold, the other is hot. This separation is
accomplished by a tiny demon who sits inside the chamber carefully sorting
fast moving molecules from slow ones to the infuriation of all teachers of
thermodynamics...... oops, wrong story. No, this separation is
accomplished by a valve (this I find hard to believe) which allows the
fast moving outer layers of the vortex to exit from one tube and forces
the remainder of the air to exit the second tube where it experiences a
drop in pressure and consequently in temperature.
And if you believe that I have some swampland in Dedham to sell you.
My student's first model R-H tube did not accomplish any appreciable
temperature differences.
Construction suggestions? Help with theory?
David Strasburger
Noble and Greenough School
Dedham MA