A METHOD FOR THE PREDICTION OF THE MINIMUM PRESSURE IN TIP VORTICES FROM THREE-DIMENSIONAL FOILS

摘要

A method for the prediction of the minimum pressure in the core of a tip vortex shed from three-dimensional foils is presented. Moore's (1974) solution for the inviscid vortex sheet roll-up is combined with a generalised Lamb model for the tangential velocity distribution in the vortex. The viscous core radius is assumed to scale with the boundary layer thickness at the trailing edge on the suction side as computed by a two-dimensional viscous-inviscid interaction method. The method is applied to elliptical foils and the calculations compared with the cavitation inception data of Fruman et al (1992), McCormick (1962) and Platzer and Souders (1980).