New Developments Around Sheet and Tip Vortex Cavitation on Ships Propellers

Abstract

A concept of tip vortex cavitation on propellers is described qualitatively, leading to the distinction of trailing vortices, local tip vortices and leading edge vortices. Improvements of the inception behaviour using this distinction are presented. Observations on developed tip vortex cavitation are given to show that the concept of vortex bursting seems inadequate. The problem of "broadband" vibrations due to a cavitating tip vortex is illustrated. Arguments are given for the fact that a three dimensional approach is necessary to describe shedding of cloud cavitation at the trailing edge of a sheet cavity.