ASA 125th Meeting Ottawa 1993 May

4pSA6. Sound pressure field into reverberant chamber containing structures excited acoustically.

Hugues Nelisse

Alain Berry

F. Charron

Jean Nicolas

G.A.U.S., Mech. Eng. Dept., Univ. de Sherbrooke, Sherbrooke, PQ J1K 2R1, Canada

A method has been developed to obtain the sound pressure field for all points in a large reverberant chamber whether or not it contains a flexible structure excited acoustically by a so-called diffuse field. The approach is based on an integral equation method for the pressure in the chamber. The Helmholtz--Kirchhoff theorem is expressed using a pressure jump function across the surface of the structure [see, for instance, D. Ouellet et al., J. Acoust. Soc. Am. 89, 2131--2139 (1991)]. A modal expansion over modes of rigid cavity and in-vacuo modes of the structure is used. It leads to a set of linear coupled equations reflecting the existence of a fluid--structure interaction. Numerical resolution of the set of equations allows one to obtain physical quantities of interest, such as the distribution of pressure on each side of the panel and consequently the jump of sound pressure across the structure. Convergence of the solution, as well as its frequency range of validity, will be discussed.