Influence of source motion, wind, and temperature profiles on the effective impedance of an absorptive surface

This paper presents a theoretical study of the sound field due to a moving source placed above an absorptive surface in a stratified medium in the presence of wind and sound speed profiles. The current analysis starts with the general equations for an isentropic inviscid flow field. A monopole source is assumed to be traveling parallel to the absorptive surface at a constant speed. The standard Lorentz transform can be applied and the Fourier decomposition can be used to express the sound field in an integral form that is amenable to further mathematical treatments. Either the fast field computation or the method of steepest descent can be used to evaluate the integral. A two-dimensional formulation was considered initially, but it can subsequently be extended to three-dimensional flow fields. The effect of source motion, wind, and temperature profiles on the acoustic properties of the absorptive surfaces have been explored.