INFLUENCE OF MEAN FLOW ON BOUNDARY-LAYER GENERATED INTERIOR NOISE

An analysis is made of the ''interior noise'' produced by high, subson ic turbulent how over a thin elastic plate partitioned into ''panels'' by straight edges transverse to the mean flow direction. This configu ration models a section of an aircraft fuselage that may be regarded a s locally flat. The analytical problem can be solved in closed form to represent the acoustic radiation in terms of prescribed turbulent bou ndary layer pressure fluctuations. Two cases are considered: (i) the p roduction of sound at an isolated panel edge (i.e., in the approximati on in which the correlation between sound and vibrations generated at neighboring edges is neglected), and (ii) the sound generated by a per iodic arrangement of identical panels. The latter problem is amenable to exact analytical treatment provided the panel edge conditions are t he same for all panels. Detailed predictions of the interior noise dep end on a knowledge of the turbulent boundary layer wall pressure spect rum, and are given here in terms of an empirical spectrum proposed by Laganelli and Wolfe. It is expected that these analytical representati ons of the sound generated by simplified models of fluid-structure int eractions can used to validate more general numerical schemes. (C) 199 6 Acoustical Society of America.