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

1aPA5. Numerical modeling of unsteady flow in the neighborhood of a thermoacoustic stack.

A. S. Worlikar

O. M. Knio

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

A low-Mach-number compressible flow model for the simulation of acoustically driven flow fields within thermoacoustic couples is constructed. The model is based on the assumption that length of the thermoacoustic stack is much smaller than the wavelength of the driving standing wave. The latter assumption is used to obtain a simplified description of the impact of acoustic waves while retaining all of the essential features of the unsteady flow developing in the neighborhood of solid boundaries. Results of numerical simulations are presented which illustrate the nonlinear response of the flow to different driving amplitudes and frequencies. [Work supported by the Office of Naval Research.]