Spectral Analysis of Noise Characteristics Caused by Ship Propeller Cavitation

The theoretical model of ship propeller cavitation noise described by random acoustic pulse sequence is presented in this paper. To mathematically describe the basic propeller cavitation noise spectral characteristics, a quasi-periodical pulse series with random position modulation described by odd bilateral exponential attenuate function is proposed. The general spectral formula of propeller cavitation noise is derived. Comparison between the theoretical results and data analysis proves the correctness of the theoretical model. And the line spectrum frequencies and altitudes can be predicted by this model for ships with different types and speeds.