Acoustic detection of propeller cavitation

Some of the acoustic correlations of cavitation noise caused by a propeller were analyzed. Digital signal processing techniques were used to quantify the dynamic structure of the cavitation produced by many ships. Consistent differences were observed between ships as to position, bandwidth, and rate of spectral transitions. It was found that there are no invariant cues across ships for cavitation noise. Some rising, falling, or complex transitions were found. It seems that the rotation speed of the propeller cannot explain these differences. Several original hypotheses are proposed to explain these findings