Hydro-acoustic and noise analysis of DTMB4119 marine propeller at different advance coefficients using DES turbulence model

Investigating the Hydro-acoustic behaviour and noise of marine propellers is very important, especially in underwater vessels and submarines. The present study aims to numerically model the hydrodynamic noise of a benchmark marine propeller using the computational fluid dynamics method based on the finite volume method under open water conditions. The DES turbulence model is used in the numerical simulation, which is a good model for modelling small eddies near the wall and covers the advantages of both LES and RANS models. To increase the accuracy of the numerical solution, a finer grid has been used on the blades tips, hub, and boss. According to the investigations, time step independence occurs for 0.001 s. In the following, the numerical analysis of the hydrodynamic noise of the DTMB4119 propeller has been extracted at the advance coefficients of 0.5–1.1 and distances of 1D to 10D from the propeller in the axial directions and perpendicular to the fluid flow. Based on the obtained results, the highest level of noise emission in the flow direction is related to low frequencies, and with the increase in frequency and distance from the noise source, the emitted noise level decreases. Increasing the distance from the noise source from 1D to 10D decreases the emitted noise level by 40 dB. For every 0.1 reduction in the advance coefficient, 10 dB is added to the noise emission level in the axial direction.