Study of Nuclei Distribution and Vortex Diffusion Influence on Nuclei Capture by a Tip Vortex and Nuclei Capture Noise

Abstract

Earlier studies of cavitation nuclei behavior in the presence of a Rankine tip vortex have shown that the nuclei is attracted or captured by the vortex pressure field and during this process noise is produced by the rapid nuclei growth. The present paper extends the study of Ligneul and Latorre (1989). The capture of nuclei by the tip vortex was characterized by an index M which depends on the nuclei radius, initial location, and the vortex circulation. To clarify the nuclei distribution effected by this capture process, the frequency of nuclei capture is derived in terms of the nuclei distribution N(R). The influence of the tip vortex axial diffusion on the nuclei capture process is formulated and number results presented to show how vortex diffusion delays the nuclei capture. The paper closes with a discussion of the numerical simulation of the nuclei capture and noise generation by the tip vortex.