Noise from Tip Vortex and Bubble Cavitation

摘要

This paper presents results from experiments designed to study the sound fromdifferent types of propeller cavitation. The propellers used in the tests produced tip vortex and travelling bubble cavitation. The spectral content, directivity, and waveform of the far-field sound were measured, in essentially free-field conditions up to 100 kHz. These data were then correlated with information about the cavity dynamics, obtained from visual observations. Vibrational modes on the tip vortex cavities produced sound at characteristic frequencies. Bubble cavitation by itself produced very broadband noise, and strongly affected the vortex cavitation noise mechanisms if the free bubbles entered the tip vortices. The noise from both kinds of cavitation was directional. Keywords: Propeller, Cavitation, Noise, Spectra, Directivity, Waveform, Canada. (JHD)