Numerical analysis of tip vortex captation behavior and noise on hydrofoil

Abstract

In this study, tip vortex cavitation behavior and noise are numerically analyzed. Eulerian-Lagrangian approach is used to simulate the tip vortex cavitation on the hydrofoil. In this approach, the flow field and cavitation behavior are computed by Eulerian and Lagrangian point of view, respectively. The vortex flow field is simulated by combining Moore and Saffman's vortex core radius variation equation with Sculley vortex model. The tip vortex cavitation behavior is analyzed by coupled Rayleigh-Plesset equation and trajectory equation based on Newton's 2nd law. Kamiirisa's experimental nuclei data are adopted to produce computational cavitation nuclei population and the nuclei are released in the vortex flow field. The tip vortex cavitation trajectories and radius variations of the nuclei are calculated according to the initial sizes of the nuclei. Noise is analyzed using time dependent cavitation bubble position and radius variation data. When the acting pressure on the nucleus goes down below the vapor pressure, the nucleus grows into a cavitation bubble. And, the cavitation bubble emits very high amplitude noise during collapse stage. This study may become a foundation of the vortex cavitation study. Copyright ？ 2006 by ASME.