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

Preprint, 2025

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-omega turbulence model. An erosion indicator based on the squared material derivative of pressure 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.