Sound radiation from a thin infinite plate in contact with a layered inhomogeneous fluid

Abstract

In this paper the sound radiation from a thin infinite plate in contact with a layered inhomogeneous fluid subjected to single point excitation is studied. Sources contributing to the inhomogeneity are discussed, and the fluid is analytically expressed as a layered inhomogeneous field. Using Hankel transform, the equations governing the fluid–structure interaction are solved. The asymptotic form of the radiation pressure at far field is obtained using the method of stationary phase. Numerical examples show that the sound radiation patterns from a plate in contact with an inhomogeneous fluid is much more complicated than that in a homogeneous fluid. Three different radiation patterns (bell, disc, and their combination) were observed in the numerical examples, and the radiation patterns are sensitive to the field parameters. Depending on frequency, the sound pressure at far field is either magnified or reduced compared with that in a homogeneous fluid. And beyond some frequency the sound pressures are almost zero.