Study on the Influence of Unsteady Cavitation on the Hydrodynamic Performance of Propeller

Abstract

Aiming at the effect of cavitation on the propeller performance of underwater vehicles during navigation, this paper is based on the Reynolds Averaged Navier Stokes method combined with the Schnerr-Sauer cavitation model and the RNG \(k - \varepsilon\) turbulence model. The comprehensive effects of cavitation number, advance coefficient, rotational speed and skew angle on the cavitation hydrodynamic characteristics of the MAU4-40 propeller widely used in marine industry are systematically analyzed. The results show that the cavitation phenomenon will gradually decrease with the increase of the advance coefficient or the cavitation number. With the increase in cavitation number, the thrust and torque of the propeller increase gradually. With the increase in propeller rotational speed, the hydrodynamic characteristics of the propeller show the trend of first increasing and then decreasing, with the maximum value appearing at \(n = 30rps\). The blade vorticity cloud and wake tip vorticity of the propeller show different changing trends. The cavitation area and hydrodynamic force of the propeller decrease with the increase of the skew angle, and thrust and torque reach their maximum when the skew angle \(\theta = 18^{^\circ }\). This study not only focuses on the overall effect of cavitation on propeller performance, but also goes deep into the details of thrust and torque, blade vorticity cloud map and wake tip vortex morphology, so as to conduct a comprehensive and in-depth analysis of propeller cavitation hydrodynamic characteristics. The complex effects of several key parameters on its performance are revealed, which provides powerful theoretical support and practical guidance for the optimal design of the propeller.