Cavitation noise characterization of two B-series propeller models in the cavitation tunnel

Analysing characteristics of propeller cavitation noise is necessary in relation with the identification of noise signature in conjunction with both surface ship and submarine operations. Since, the noise signature is determined by propeller, flow and machinery noise then any vessel that has certain propeller, hull shape and machines will have a peculiar signature. The propeller cavitation noise can be generated by means of experiment performed in a cavitation tunnel. This study reports some results of the noise characterization experiment conducted in the Cavitation Tunnel available at the Indonesian Hydrodynamic Laboratory, Surabaya, Indonesia. Two B-series propeller models, i.e., 4 and 7-blade were studied in the experiment. Time-Frequency distribution, namely Wigner-Ville Distribution (WVD) is applied to observe the characteristics of the cavitation noise. Results show that the WVD can differentiate whether the propeller cavitation noise is generated either by the 4 or 7-blade propeller. In this study, three different kinds of categories in the appearance of cavitation are distinguished, i.e., when the propeller does not experience cavitation, if only hub and tip vortex cavitation develop and when various cavitations occur simultaneously.