Comparative study of different cavitation erosion assessment methods in cavitating flow around a Delft Twist hydrofoil

Abstract

Abstract Cavitation erosion is a common phenomenon in hydraulic machines, which severely threatens their stable operation. Although several methods for erosion risk assessment have been proposed, few researchers work on the comparative study of different cavitation erosion assessment methods. Therefore, this study utilized Large Eddy Simulation (LES) combined with Zwart-Gerber-Belamri (ZGB) cavitation model to conduct the numerical simulation for the cavitating flow around a Delft Twist hydrofoil. The Erosive Power Method (EPM), Improved Gray Level Method (IGLM) and Energy Conservative Method (ECM) are employed separately to evaluate the cavitation erosion. Among the three results, the EPM results cannot accurately predict erosion in the middle region and trailing edge region, where the U-shaped vortex collapse. The results of IGLM and ECM can predict the erosion in the middle region and erosion caused by the U-shaped vortex at the trailing edge. IGLM still needs artificial thresholds, while ECM emphasizes areas with higher cavitation risk by amplifying parameter n. The ECM method is more objective from the simulation results.