Modeling study of wake cavitation characteristics of DTMB propeller based on numerical computation

Abstract

Based on the RANS method using unstructured grids, numerical simulations of cavitation on the DTMB propeller under uniform inflow conditions were conducted. Through numerical studies of pressure pulsations under different cavitation numbers, it was found that at low cavitation numbers, the pressure fluctuations become irregular with higher amplitude and increased noise. As the cavitation number increases, the pressure tends to stabilize and exhibits periodic fluctuations. Two linear regression models were constructed by the correlation analyzing between the spectral characteristics of the pressure pulsation signals and the operating conditions. The model for the rotational speed and shaft frequency amplitude of the 4381 propeller indicates that the amplitude of the second harmonic of the shaft frequency increases with the advance coefficient. The model for the skew angle and the fourth harmonic amplitude shows that an increase in the skew angle leads to a gradual increase in the amplitude of the fourth harmonic.