Numerical prediction of cavitation erosion in a water-jet propulsion system

• Numerical cavitation erosion assessment of a commercial waterjet propulsion system. • RANS-based modeling combined with a (DP/Dt) 2 - based erosion indicator. • Erosion risk predictions validated against experimental paint erosion tests. • Multiple operating conditions analyzed to assess methodology robustness. • Computationally efficient tool for early-stage industrial erosion assessment. This study presents a numerical method for predicting erosion in a commercial water-jet pump. The multiphase flow is modeled using the Schnerr-Sauer cavitation model within an unsteady RANS framework, employing the SST k- ω turbulence model. An erosion indicator based on the squared material derivative of pressure, ( D P / D t ) 2 , is used to identify high-risk regions of aggressive cavitation collapse. Three operating conditions are investigated to assess the robustness of the numerical methodology and effect of the operating conditions. This study uniquely examines cavitation erosion risk under multiple operating conditions, providing a comprehensive assessment of numerical prediction methods. The numerical predictions successfully captured erosion-prone regions, showing good agreement with experimental data. However, RANS-based modeling exhibited limitations in resolving transient cavitation structures, leading to an underestimation of erosion extent. Despite the limitations, the proposed RANS-based framework serves as a computationally efficient early-stage assessment tool for cavitation erosion in industrial applications.