The Scattering Of Acoustic Waves By Buried Sphere For Subcritical Grazing Angles

The research background of this paper is detecting buried mines in shallow sea. Some kinds of sediment and the forming of buried mines are presented in the paper. The energy distribution in the sediment was analyzed, and the depth of shallow bury was defined.By using the corresponding relationships between spherical wave functions and sound fields of multi-pole sources, and using the expressions for reflected and refracted fields of spherical waves on the interface, formal solution of sound scattering on elastic sphere, lying near the interface of fluids, is given in the paper.Total internal reflection will occur at the grazing angle below the critical angle, but there is evanescent wave in the lower medium. In order to study the object's scattering in the evanescent wave field, a simplified model is given in the paper at first. A rigid ball's scattering is analyzed in the evanescent wave field. Numerical calculation had been carried out.