Development of integrated noise analysis systems for ship propellers considering hull wake

Recently, the requirements for underwater radiated noise (URN) reductions in ships have become significant issues, driven by concerns over the impact of naval vessel performance and noise on marine ecosystems. The majority of URN generated from ships is attributed to the propeller. This study developed the integrated noise analysis systems that predict and analyze all the significant noises generated from the propellers, considering the hull wake. Since each type of noise has different sources and mechanisms, it is essential to analyze all types of noise to evaluate the propeller noise performances comprehensively. The model was developed for cavitation noise by compression and expansion motion of bubbles to evaluate the radiated noise. For non-cavitation noise, a noise model on the frequency domain was derived to cover the noise generated by changes in the wake. The unsteady pressure on the rotating blade was obtained using flow fields and wall pressure spectrum, extending to high frequencies. The developed system provides a valuable tool for propeller optimization designs by minimizing URN while considering the shape of the hull and appendages.