Numerical study of acoustic characteristics of a marine propeller in non-uniform flow

The impact of increased Underwater Radiated Noise (URN) over the past two decades on marine mammals has resulted in the pressing requirement to reduce it. Shipping contributes immensely to the URN. Propeller noise is a major source of URN. The reduction in Propeller noise can hence significantly help in the reduction of URN. With the sole objective of improving the hydrodynamic performance and ways to prevent cavitation are being employed in design propellers. However, the reduction of non cavitating noise produced by the propeller would still remain a challenge. In this present study, effect of 2D non-uniform flow on the acoustic and hydrodynamic characteristics is presented. The non-uniformity in the flow is generated by placing a flat plate in front of the propeller. The SPL has been calculated by using the two-step Ffowcs William and Hawkings (FW-H) equations from the pressure distribution at various points around the propeller. SPL at various points in the downstream and propeller disk plane are numerically predicted and discussed.