A Study on Underwater Radiated Noise Characteristics of Naval Vessel with PRAIRIE According to Air Leakage Condition

Recently, a propeller air-induced emitting (PRAIRIE) system has been adopted for naval vessels to reduce propeller cavitation noise. However, air leakage occurs around the injection hole because of the low pressure around the propeller blade. To investigate the noise characteristics of air leakage, we measured underwater radiated noise during sea trials using a shut-off valve. Noise data were analyzed in terms of the band energy level and signal modulation. We found that the air leakage of the PRAIRIE system affects the characteristics of the underwater radiated noise.