A novel approach for description of nonlinear field radiated from a concave source with wide aperture angle

Abstract

A new approach is proposed to study the nonlinear sound field radiated from a concave spherical source with a wide aperture angle. The nonlinear sound field is theoretically described by a set of equations deduced reversely from the second-order Westervelt nonlinear wave equation. To examine the validity of the theoretical model, numerical calculations are performed on a concave spherical radiator with the aperture angle wide up to 40°. Numerical calculation is implemented by the finite difference time domain algorithm in the oblate spheroidal coordinate system. Numerical results are in agreement with those obtained by Kamakura’s solutions.