Structure Noise Prediction of Submarine by Propeller Excitation

Abstract

When boundary element (BE) was coarse, the general Gauss quadrature of Helmholtz integral equation (HIE) on it was not accurate. A mesh-less refined integral algorithm (RIA) of BEM was used to overcome this problem. Then RIA coupled with FEM/CFD was applied to predict submarine propeller excited hull underwater noise. The thrust and torque excitations of propeller simulated via CFD were loaded on to submarine respectively to calculate the acoustic response, and the sound power and main peak frequencies were obtained. Results show that, thrust mainly excites submarine axial mode and high sound area appears at the two conical-type ends, and torque mainly excites circumferential mode and high sound area appears at the broadside of cylindrical section, but with rather smaller sound power and radiation efficiency than the former. So, main attention should be focused on thrust excitation when perform the sound radiation reduction of submarine that propeller excited. Keywords: Submarine, Propeller excitation, Refined integral algorithm, Vibro-acoustic, CFD/FEM.