Numerical prediction of cavitation erosion with emphasis on investigating the influence of driving pressure definition

This work devoted to analyzing the influence of the definition of driving pressure on the erosion prediction. For that, the density-corrected shear stress transfer turbulence model and the Sauer cavitation model are used to simulate the unsteady cavitating flow around a twisted hydrofoil. The numerical results were verified by compared to the cavitation shedding rate and the transient cavity behaviors in the experiment. The erosion energy in the flow field was defined based on the transient pressure and time-averaged pressure field, respectively, and the wall erosion load was predicted by mapping the erosion energy to the hydrofoil surface. It is found that using the time-averaged pressure as the driving pressure can predict more reasonable and more agreeable erosion simulation results, the instantaneous wall erosion load is more consistent with the transient evolution of cavity structures, and the distribution of accumulated wall erosion load is comparable to the erosion region in the experiment. Meanwhile, it is found that the main eroded area on the middle of the hydrofoil is caused by the continuous collapse of the small vapor structures shedding from the sheet cavity closure region, and the scattered pitting area in the middle of the trailing edge is mainly related to the ultimate collapse of cloud cavity.