Numerical Investigation of Propeller Cavitation Noise Characteristics and Sound Generation Mechanism

Objectives Cavitation, as one of the most important noise sources around the propeller, significantly enhances the far-field radiated noise and brings many adverse effects. In order to effectively suppress the propeller cavitation noise, it is necessary to carry out research on the propeller cavitation noise characteristics and sound generation mechanism. Methods In this study, the cavitation noise around a PPTC propeller is simulated using the Large Eddy Simulation (LES) coupled with the permeable Ffowcs Williams and Hawkings (PFW-H) equation, focusing on the effect of cavitation on the spectral characteristics of far-field noise and the cavitation noise generation mechanism. Results The predicted hydrodynamic results agree well with the experimental data. It is found that there is a significant periodicity in the evolution of both sheet cavity (SC) and tip vortex cavity (TVC) around the propeller, and thus both contribute high intensity dominant frequency noise. Sheet cavity evolves with incipient and collapsing processes, which are accompanied by transient cavity volume variations, leading to an intensification of high-frequency broadband noise. Tip vortex cavity evolves with a volume rebound behavior, which induces high-intensity continuous acoustic pressure pulsations, and thus induces significant noise peaks at frequencies above the dominant frequency. Conclusions This paper provides a theoretical basis for the proposal and implementation of propeller cavitation noise control strategies in engineering.