DANSK DSF/ISO/FDIS 20233-2 PDF

This document specifies a model test method for propeller cavitation noise evaluation in ship design focusing mainly on the noise source localization. In order to specify the location of noise source, visual observation of cavitation is the most practical way in view of spatial resolution and efficiency, as the main source of hydrodynamic noise in merchant ship is cavitation. In addition to this observation, noise source localization technique using hydrophone array is under development for supporting the observed results.[1] The procedure comprises of model test set-up, noise measurements, data processing and source localization. The target noise source is propeller cavitation. Thus, this document describes the test set-up and conditions to reproduce the cavitation patterns of the ship, which is the same as in the ISO/DIS 20233-1. The noise measurements are performed using a hydrophone array for the source localizations. Therefore, the instrumentation of the hydrophone array is to be addressed as well as a suitable array signal processing of the measured data. Finally, a method how to visualize and to interpret the results is to be presented.