ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

4pPA2. A model of the temperature discontinuities found between the elements of thermoacoustic engines.

James R. Brewster

Richard Raspet

Dept. of Phys. and Astron., Univ. of Mississippi, University, MS 38677

In experimental investigations of thermoacoustic engines, the temperature difference required to drive these devices at high amplitude has been found to be markedly higher than that predicted by linear theory. This discrepancy is due in part to a significant difference in temperature that has been observed between stack sections and their adjoining heat exchangers. It will be shown that the existence of a step in the longitudinal temperature profile is a finite-amplitude effect, not encompassed by the linear theory, and is essential if heat is to be transferred between elements of the engine. Physical insights obtained from a simple model of the heat transfer process based on the assumption that the working fluid is inviscid and incompressible will be presented. This will be followed by consideration of how the existence of viscosity and fluctuations in the density of the working fluid affect this model. [Work supported by the Office of Naval Research.]