Energy-Based Cavitation Erosion Risk Modeling of Sheet-to-Cloud Cavitation of a Hydrofoil

Cavitation erosion presents a major challenge in hydraulic machinery and naval applications, damaging material surfaces and increasing maintenance costs; however, the relationship between hydrodynamic behavior and the resulting material response is not fully understood. High Reynolds number cavitation erosion experiments were recently performed in the US Navy’s William B. Morgan Large Cavitation Channel. Surface pitting statistics and near-surface hydrodynamic quantities were measured on a hydrofoil subject to sheet-to-cloud cavitation. To complement the experiments, we incorporated a cavitation erosion risk model based on the pressure and vapor volume fraction into large-eddy simulations. The risk model is derived using an energy-balance approach analyzing the potential energy within a cavity. Simulations of the most erosive regime where the cavity length is about half the chord are validated with the experimental measurements corresponding to nearly full-scale naval control surface conditions. The highest levels of local energy impact rate and accumulated energy, used in erosion aggressiveness quantities, occur near the transition from sheet-to-cloud cavitation at the 50% chord location. Correlations between surface pressure and other hydrodynamic quantities, as well as the accumulated energy, are analyzed, along with the quantification of intermittency. The spatial distribution of the aggressiveness indicators is compared to the experimentally observed pit distributions.