The issues of noise and vibration related to the propulsion system of vessels shines a bright light over the present day operation of sea going vessels. Some of the principal issues coming to the front are not new and are concerned with passenger and crew comfort which has been a touchstone for a decade or more. The most recent, more ominous issue is transmission of noise from transiting vessels and how this noise affects marine mammals. The tools used to analyse and define the expected levels of vibration and noise in the design phase are becoming more and more robust. The paper describes the use of computational fluid dynamics to predict the noise and vibration generated by hydrodynamic flow over the hull and the propeller(s) of the vessel. The analysis is carried out using the program OpenFOAM comparing the operating propeller performance coefficients with the open water propeller coefficients. The paper also looks at the effects of cavitation, vessel trim and propeller loading on a 140 meter car ferry. The loading, noise and vibration data will be quantified and compared to full scale vessel data.
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