Wave Noise on High Speed Ships - Source Characterization and Modeling

Compartmental noise levels on high speed craft are influenced by engine and propulsor sources, though significant noise is also generated through hydrodynamic effects. The hydrodynamic source of interest here is sometimes referred to as 'wave noise', which is caused by unsteady pressures developed on the hull when the vessel displaces water. This effect is typically a concern for vessels transiting at 20+ knots. The resulting hull vibrations can produce hazardous noise levels in forward compartments if left untreated. This situation is amplified for small vessels where receiver compartments can be close to both machinery spaces and forward spaces where wave noise originates. Mitigating wave noise requires an understanding of where the noise is produced, its magnitude relative to different vessel conditions, and the pertinent paths to receiver compartments. This paper shows that it is possible to improve accuracy of noise predictions by including wave noise sources in computer-aided acoustic modeling tools. Comparisons of predictions to measurement are presented. However, additional work is needed to improve estimates of the location and magnitude of this hydrodynamic source prior to measurement.