Acoustic scattering from dual frequency incident fields

Abstract

The pressure field produced by the spatial interaction of two high frequency incident beams in a three-dimensional scattering object is investigated. Of particular interest is the radiated pressure produced in response to the difference-frequency component generated from the non-linear interaction between the beams and the scattering medium. The influence of high acoustic contrast and resonant scattering is considered in the analysis. This work presents a computational study of the scattered pressure that results from the Reynolds stress in a fluid scatterer. Using Padé approximants, it is shown that the stress tensor can be computed using a uniform expansion in the contrast gauge for the scattered pressure. This allows one to investigate scattering volumes characterized by high compressibility contrast.