Mechanocaloric Effect

mechanocaloric effect

[¦mek·ə·nō·kə′lȯr·ik i‚fekt]
(cryogenics)
An effect resulting from the fact that a temperature gradient in helium II is invariably accompanied by a pressure gradient, and conversely; examples are the fountain effect, and the heating of liquid helium left behind in a container when part of it leaks out through a small orifice.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Mechanocaloric Effect

 

an effect observed in liquid helium below the temperature of the transition into the super-fluid state (below 2.19°K): when helium flows out of a vessel through a narrow (approximately 1 μ) capillary or orifice, the helium remaining in the vessel is heated. This effect was discovered in 1939 by the British physicists J. G. Daunt and K. Mendelssohn; the effect was explained by the quantum theory of superfluidity. The inverse effect—the flow of helium induced by the introduction of heat—is called the thermomechanical effect.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.