Investigation on the cyclostationary noise of cavitating propeller in nonuniform inflow

This study investigates propeller cavitation noise under nonuniform inflow conditions using a high-skew model propeller tested in a cavitation tunnel. Cavitation regimes from non-cavitating to fully developed were examined through synchronized high-speed imaging and hydroacoustic measurements. Signal analysis was conducted in time, frequency, and cyclic domains. STFT and Welch methods showed that increasing cavitation severity leads to higher broadband noise levels, especially in low and high-frequency ranges. DEMON-based cyclostationary analysis revealed strong modulation at the blade-passing frequency during moderate cavitation, which weakens when cavitation becomes weak or fully developed. The modulation strength also varies with the advance coefficient. Results demonstrate that cavitation dynamics significantly influence both noise intensity and its modulation structure. The findings support the use of acoustic signal analysis for cavitation detection, condition monitoring, and underwater noise prediction in marine propulsion systems.