Effects of balanced skew and biased skew on the cavitation characteristics and pressure fluctuations of the marine propeller

Abstract

In order to study the relationship between ship propeller cavitation and induced pressure fluctuations, two propellers with different skew patterns are designed. The RANS method and the Schneer & Sauer cavitation model were used to solve the cavitation flow of the HSP-Ⅱpropeller and the results were in agreement with the measured data. At the cavitation condition, the balanced skew propeller shows a smaller cavitation volume than the biased skew propeller; for monitoring points above the propeller, skew type has little effect on the pressure fluctuations, the balanced propeller shows slightly lower pressure fluctuations. For a clockwise propeller (from the stern), the pressure fluctuations on the starboard are stronger than the port side. Finally, the fast Fourier transform (FFT) of the pressure signal shows that whether it is cavitation or full wetted flow, the point above the propeller contains first 3 harmonics of blade passing frequency (BPF), while the point in the wake shows only 1BPF at cavitation condition.