ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

1aPA2. Simplified model for the study of nonlinear processes in thermoacoustic engines.

A. Prosperetti

M. Watanabe

Dept. of Mech. Eng., Johns Hopkins Univ., Baltimore, MD 21218

Upon integrating the governing equations over the cross section of a thermoacoustic device, a simplified one-dimensional model is obtained. While only approximate, this model renders the study of nonlinear effects very amenable to analysis. In particular, for a thermoacoustic prime mover, the stability limits are calculated and the steady-state amplitude is estimated on the basis of a weakly nonlinear theory. For larger amplitudes, numerical results are presented. The marked propensity of the system to develop shock waves is found to be a very strong factor limiting its efficiency. [Work supported by the Office of Naval Research.]