Numerical Study of Cavitating Turbulent Flow Around Propellers: Relationship of Cavity Volume Evolution and Pressure Fluctuation

Abstract

The cavitating turbulent flows around two marine propellers, where one is a conventional propeller (CP) and the other is a highly skewed propeller (HSP), operating in non-uniform wake have been simulated by applying a mass transfer cavitation model based on Rayleigh-Plesset equation and k-omega SST turbulence model. From comparison of the numerical results with the experiment, it is noted that the unsteady cavitation patterns as well as the pressure oscillation amplitudes of the dominant components of marine propellers in non-uniform wake are reasonably predicted by present numerical methods. The results indicate that the effect of skew angle is very important on the cavitation characteristics as well as pressure fluctuations, and the amplitude of pressure fluctuation for HSP is reduced by 50–70% compared with that for CP. Therefore, the HSP propeller may help to avoid noise and vibration rather than the CP propeller. Further, the relation between hull pressures and changing cavitation patterns is verified based on CFD results, as the blades sweep through the high wake region. It is demonstrated that volumetric acceleration is the main reason for the pressure fluctuation, which agrees with the experiment by Duttweller and Brennen (2002).