HIGH-FREQUENCY RADIATION OF SOUND FROM BODIES OF ARBITRARY SHAPE.

In this paper the problem of calculating the sound field in a three-dimensional fluid of infinite extent due to a body of arbitrary shape which is vibrating harmonically is considered. Interest is focused on the case in which the parameter a/ lambda is large, where a is some characteristic dimension of the radiator. The approach here is to replace the familiar Helmholtz integral formula with an algebraic relationship which is approximately valid on the surface S of the body and to use this relationship to determine the acoustic potential at each point on S, given the normal gradient of the acoustical potential at that point. The acoustic potential exterior to the body is then calculated by numerical evaluation of the Helmholtz formula.