Directivity of spherical acoustic scattering based on COMSOL

Abstract

The acoustic scattering characteristics of spheres are the basis for studying the sound scattering law of the target. The directivity of acoustic scattering is one of the most important characteristics of the target sound scattering law. In this paper, the acoustic scattering characteristics of rigid spheres and elastic spherical shells are analyzed from the two typical basic models of the rigid sphere and elastic spherical shell. The sound scattering directivity corresponding to different ka values under different models is analyzed by COMSOL finite element simulation analysis. The change law of spheroid scattering directivity of spheres under different elastic backgrounds of the rigid sphere and elastic spherical shell is compared and studied. It is found that the scattering directivity of both rigid spheres and elastic spherical shells will change with the change of ka value. The larger the ka, the stronger the forward directivity, and the more side lobes for rigid spheres. The backward directivity is greater than the forward directivity at ka≤1, while the forward directivity of the elastic spherical shell is always greater than the backward direction. And it is not difficult to find that the directivity of rigid spheres is relatively uniform in backward scattering when ka=1. When ka>1, the directivity increases with ka, the forward directivity becomes stronger and stronger, and the side lobes gradually increase. The elastic spherical shell uses air as the internal filler, and its directivity has always been forward than backward. The forward directivity also increases with the increase of ka, and the side lobes also increase with the increase of frequency.