Prediction of cavitation erosion with different erosion risk indicators

Abstract

This present work devoted to simulate the unsteady cavitating flow around a hydrofoil and assess its erosion power predicted by different erosion risk indicators. For that, the behavior of unsteady cloud cavity is numerically reproduced using density corrected Shear Stress Transport (SST) k-¿ turbulence model and the mass transfer between vapor and water phases is modelled with the Schnerr-Sauer cavitation model. The definitions of different erosion risk indicators are mathematically derived and their performance on predicting erosion power is compared systematically. The results demonstrate that indicator, defined only with the rapid temporal variations of the pressure, is unable to distinguish the erosion area caused by cavity collapse. And the erosion risk indicator defined by time derivative of flow properties is unable to capture the main erosion occurred on the cavity closure region because the high erosion power on such area is mainly contributed by the advection term. In addition, it is founded that the full form of erosion power definition, defined by material derivative, is the best erosion indicator which can well predict the most eroded area and thus is recommended to be applied in the industrial and practical applications.