Simulation Analysis of the Effects of the Flow around Underwater Moving Bodies on the Acoustic Signal

The underwater moving bodies interacting with the water flow form a complex flow field. The changing flow field can cause the time-varying Doppler frequency shift of the acoustic signal propagating in the flow field. In this paper, the finite volume method is used to simulate the flow field behind the underwater cylindrical moving body and the horizontal rudder with different deflection angles. The simulation results show that the flow velocity behind the underwater cylindrical moving body does not change dramatically with time, while the flow field behind the rudder blade with a certain deflection angle changes dramatically with time and space. As the rudder blade deflection angle or the moving speed increases, the frequency changing period decreases and the frequency variation increases.