Development of ship radiated noise transfer functions and near-field to far-field measured signature comparisons

Abstract

Various methods exist to determine the vibration level on the wetted hull plate of a vessel—whether they be measured or predicted. Transfer functions are discussed that relate the hull vibration levels and ship’s physical parameters to the far-field radiated noise. These methods are useful to predict the noise from fisheries research vessels and other vessels such as work or cruise boats. The former need to ‘‘sneak-up’’ on fish to perform stock assessment and the latter may need to operate in environmentally sensitive areas. Predicted radiated noise is compared to measured noise to assess the accuracy. Data is also presented on measured noise data for several vessels at various separation distances approximating near- and far-field conditions. These data were taken with the vessel at zero speed.