Number 104 : December 2000 |
The Ranque (or better Ranque-Hilsch) effect was discovered more or less by accident by Georges Ranque : G Ranque : "Expériences sur la détente giratoire avec productions simultanées d'un échappement d'air chaud et d'un échappement d'air froid." Journal de Physique et le Radium 4, 1125-1155, 1933 and rediscovered by Hilsch : R Hilsch : Rev Sci Inst 18(2) 108 1947.
A typical R-H device has one input port and two outputs; compressed air at room temperature is fed in and heated air flows from one output and cooled air from the other. It is effectively a refrigerator with (apart from the air streams) no working fluid and no moving parts. Such devices have industrial uses as convenient and localized sources of very cold air and are manufactured by a number of firms, for example C C Steven in California. (www.ccsteven.com/FRAMES/SPOTCOOL.htm).
C C Steven's website states :
"Fluid that rotates about an axis -- like a tornado -- is called a vortex. A vortex tube creates a vortex from compressed air and separates it into two air streams -- one hot and one cold. Compressed air enters a cylindrical generator which is proportionately larger than the hot (long) tube where it causes the air to rotate. Then, the rotating air is forced down the inner walls of the hot tube at speeds reaching 1,000,000 rpm. At the end of the hot tube, a small portion of this air exits through a needle valve as hot air exhaust. The remaining air is forced back through the center of the incoming air stream at a slower speed. The heat in the slower moving air is transferred to the faster moving incoming air. This super-cooled air flows through the center of the generator and exits through the cold air exhaust port."
Remarkably, although the R-H effect has been known for many years it is not yet fully understood. A number of researchers have studied it with so far limited success.
See for example: W. Fröhlingsdorf, H. Unger: Untersuchungen zur kompressiblen Strömung und Energietrennung im Wirbelrohr nach Ranque und Hilsch, Dissertation, Shaker Verlag (ISBN 3-8265-2829-8), Ruhr-Universität Bochum, 1997. Tim Cockerill : www.cockerill.net (this website carries detailed information about research on the R-H effect).
In recent years the R-H effect (or rather a garbled version of it) has been brought into play to 'explain' alleged shortcomings of astrophysical theory. See Renzo Boscoli in Infinite Energy Magazine (www.mv.com/ipusers/zeropoint/ - a forum for heterodox views on 'Cold Fusion'), Richard Milton ('Is the Sun hot ?') in Mensa Magazine (Nov 1999) and Commensal No. 103, and Bob Cooper ('The Ranque Effect - Key to the Mysteries of the Universe ?') also in Commensal No. 103.
The R-H effect is exemplified by an ingenious but highly artificial device whose detailed functioning is still only partly understood. I find it difficult, looking at the matter with a background of physics and engineering (plus just common sense) to see how the working of such a device has any relevance to the processes taking place, for example, in the interior of the Sun.
Alan Edmonds