PREDICTION OF CAVITATION ON SHIPS

The emphasis of this paper is on challenges in simulation of cavitating flows, especially flows around propeller and rudder. First the sources of errors in predictions based on Computational Fluid Dynamics (CFD) are highlighted: the accuracy of geometry, grid quality and fineness, turbulence modeling and cavitation modeling. The interaction between errors from different sources is also discussed. The importance of turbulence in the flow upstream of propeller and the difficulty of accounting for it is described next. Special attention is paid to the prediction of tip-vortex cavitation and to scale effects. Results from simulations are compared to experimental data from SVA Potsdam, except for the full-scale analysis of flow around hull, propeller and rudder, for which no experimental data is available. It is concluded that cavitation can be predicted to a degree which makes simulation an indispensable tool for design and optimization of maritime vessels.