Model of cavitation noise modulation spectrum of ships with skewed propellers

摘要

A theoretical model of a propeller cavitation noise modulation spectrum of ships with skewed propellers is proposed.According to the relationships between the wake velocity and the cavitation noise volume and between the propeller rotational speed and the number of bubbles,a mathematical expression of the cavitation noise modulation spectrum is derived.Theoretical analysis and simulation show that the difference between the blades is the main reason for the existence of a shaft frequency line spectrum in the modulation spectrum and that the main affecting factors of the modulation spectrum intensity of blade frequency in the modulation spectrum are the propeller’s skew angle and revolution.The results presented in this study provide a theoretical basis for the analysis and extraction of modulation spectrum characteristics of the radiated noise and also have a reference value for the low-noise structure design of ship propellers.