A validation study of the model test method for propeller cavitation noise prediction

Abstract

Propeller cavitation noise, one of the main sources of ship noise, has recently gained much attention owing to its possible adverse effects on marine life. In order to predict full-scale propeller cavitation noise, a model test method using the large cavitation tunnel at the Korea Research Institute of Ships & Ocean engineering (KRISO) was developed. The standard procedure consists of reproduction of the noise source, noise measurement, post-processing, and noise scaling. The propeller cavitation is reproduced in the same manner as in the cavitation observation test, and the noise is measured. After correcting the multipath effect and the background noise, the model-scale source level (SL) is estimated. The transfer function (TF), which represents the multipath effect, can be measured using a virtual source (or two sources for the twin propeller). Finally, the full-scale SL is predicted by a scaling method. This paper focused on validation of the TF correction and the scaling methods that most affect noise prediction. Validation tests were performed on two ships: a 14,000 TEU container carrier with a single propeller and a 176 K LNG carrier with twin propellers. The validation study confirmed the effectiveness of the model test method in predicting full-scale propeller cavitation noise.