AN EMPIRICAL APPROACH FOR PROPELLER TIP VORTEX CAVITATION NOISE

Abstract

In this study, the TVI (Tip Vortex Index) technique has been applied to a marine propeller to predict the noise due to tip vortex cavitation. The benchmark DTMB4119 model propeller has been chosen for the hydro-acoustic performance analysis in open water condition. The flow around the model propeller has been solved both under non-cavitating and cavitating conditions by lifting surface method (LSM) based on potential flow theory and RANS (Reynolds Averaged Navier Stokes) approach based on finite volume method. TVI technique has been coupled with LSM. Uncertainty study based on grid convergence index (GCI) has also been done for RANS approach to determine the optimum grid number. The results of LSM and RANS methods have been validated with the available experimental data under non-cavitating condition. LSM and RANS methods have also been compared in terms of cavity patterns and hydrodynamic performance. The effects of blade number, cavitation number and advance coefficient on propeller tip vortex cavitation noise have been discussed.