Influence of shallow ocean front on propagation characteristics of low frequency sound energy flow

Abstract

To clarify environment of shallow ocean front propagation mechanism and characteristic of low frequency sound signal, using the Finite Element Method (FEM), set up a little bit of sound source under the action of shallow water waveguide all low frequency sound field of numerical model, and using the model the simulation analysis of the different nature of the oceanic front, oceanic front gradient and oceanic front slant range of shallow water waveguide all the influence law of low frequency sound energy flow propagation characteristics. The simulation results show that, compared with the case without ocean front, the low-frequency sound energy flow will significantly leak to the sea bottom in the ocean front area under the transition from warm water area to cold water area. In the case of transition from cold water zone to warm water zone, the low frequency sound energy flow will reduce the energy leakage to the seabed from ocean front zone, and more energy is confined to the sea layer. With the decrease of the absolute value of the ocean front gradient, the energy leakage from the ocean front to the seabed gradually decreases, and the main leakage location also moves backward. The variation of ocean front tilt distance has little influence on the propagation of sound energy flow in the ocean front area, but at the rear of the ocean front area, the sound energy flow gradually leaks to the seabed with the increase of ocean front tilt distance.