Prediction of tip vortex cavitation inception using coupled spherical and nonspherical bubble models and Navier?Stokes computations

• Published in: Journal of marine science and technology 2004-01, Vol.8 (3), p.99-108
• Main Authors: Hsiao, Chao-Tsung, Chahine, Georges
• Format: Article
• Language: English
• Subjects: Boundary conditions; Cavitation; Free surfaces; Marine; Naval engineering; Physics; Reynolds number
• ISSN: 0948-4280; 1437-8213
• DOI: 10.1007/s00773-003-0162-6

A spherical and a nonspherical bubble dynamics models were developed to study cavitation inception, scaling, and dynamics in a vortex flow. The spherical model is a modified Rayleigh-Plesset model to account for bubble slip velocity and for nonuniform pressures around the bubble. The nonspherical model is embedded in an unsteady Reynolds-averaged Navier-Stokes code with appropriate free-surface boundary conditions and a moving chimera grid scheme around the bubble. The effect of nonspherical deformation and bubble/flow interaction on bubble dynamics is illustrated by comparing spherical and nonspherical models. It is shown that nonspherical deformations and bubble/flow interactions are important for an accurate prediction of cavitation inception. The surface-averaged pressure-modified Rayleigh-Plesset scheme is a significant improvement over the conventional spherical model, and is able to capture the volume changes of a bubble during its capture. It is also a fast scheme for studying scaling. In a preliminary study, the scaling effects on cavitation inception were examined using two different Reynolds numbers owing to two different chord lengths. The nuclei-size effect on the prediction of cavitation inception was also studied, and its important effects are highlighted.