Three-dimensional Acoustic Effect by Seamounts in Shallow Sea

The complex shallow sea topography will lead to stronger three-dimensional (3D) acoustic effect. The direct numerical simulation of 3D shallow sea sound field under seamount environment is carried out by using the Finite Element Method (FEM). Taking acoustic transmission loss as the research object, the influence of seamounts on the propagation of low frequency acoustic signals in shallow sea in the range of kilometers is analyzed by controlling the seamounts' cross section and the sound source frequency. The simulation results show that the increase of the seamount radius in the direction of the source axis will decrease the blocking effect and increase the backscattering effect. The increase of the radius of seamount in the direction perpendicular to the source axis will increase the 3D scattering effect at azimuth obviously. At the same time, with the increase of the source frequency, the 3D scattering effect will gradually increase.