Numerical computation on the scattering sound field distribution of rigid sphere in shallow water waveguide

Numerical computational model about the scattering fields of rigid sphere in shallow water waveguide is accomplished using boundary element method and normal mode model. A kind of modified CHIEF boundary element method is used to solve the non-uniqueness problem at characteristic frequency for exterior sound field computation. The green function for shallow water waveguide acoustic wave propagation is modified based on the normal mode model. The acoustic pressure in the far field yields Kirchhoff Helmholtz equation and the scattering sound field distribution of rigid sphere in a Pekeris waveguide is achieved. Also the scattering sound field distribution of rigid sphere in the free field is calculated. The results indicate that the waveguide influences the sound propagation, and it need to pay attention during the test.