Propeller cavitation noise investigations of a research vessel using medium size cavitation tunnel tests and full-scale trials

The rising environmental awareness of various adverse emissions by commercial shipping has recently targeted Underwater Radiated Noise (URN) due to its potential impact on marine mammals. Amongst the various sources on-board a commercial ship, cavitation is the dominating one following its inception. In order to ensure acceptable noise levels for sustainable shipping, accurate prediction of the noise signature is vital. Within this framework, a widely utilized method for full-scale noise prediction is to conduct model tests in cavitation tunnels and to extrapolate to full-scale. The aim of this paper is to provide invaluable URN data of a full-scale vessel and its prediction using cavitation tests from a medium-sized tunnel to evaluate the prediction methodology. Extrapolated URN data based on the tunnel tests was compared with the data obtained from the full-scale trials with The Princess Royal in order to assess the prediction methodology. The comparisons indicate that, whilst the ideal experimental approach is to conduct such involving tests with a full-hull model in large cavitation tunnels, the medium size facilities using dummy-hull models with wake screens, can still provide a very useful means for the URN investigations with a rapid turn around and an economical way of conducting such tests.