Investigation of cavitation jet erosion based on the Eulerian-Lagrangian approach coupled with dynamic mesh

Cavitation jet nozzles are widely used for cutting, crushing, cleaning, etc., but the erosion behavior of cavitation jets remains highly unpredictable owing to the multiscale complexity of cavitation. The present work integrates an energy balance approach with a hybrid Eulerian–Lagrangian cavitation model, and incorporates the dynamic mesh approach to represent the erosion morphology explicitly. The large eddy simulation approach is used to calculate the turbulent flow dynamics, while a random nucleation method is applied to consider cavitation nuclei. A two-way transformation algorithm is employed for bridging between the continuous phase (modeled in the Eulerian framework) and the discrete bubbles (tracked through the Lagrangian approach). An erosion prediction indicator using the material derivative of multiscale vapor volumes is used to assess the cavitation erosion distribution and compare with the previous experiment [Liu and Ma, “Erosion behavior of aluminum by an inclined cavitating jet,” Wear 474–475, 203751 (2021)]. A hybrid model coupling cavitation erosion risk with the dynamic mesh technique is proposed to enable high-fidelity prediction of erosion hotspots. The proposed model demonstrates enhanced accuracy in cavitation features through multiscale coupled simulation of large cavities and tiny bubbles, as well as in cavitation erosion distributions by dynamically adjusting mesh nodes according to the erosion risk distribution and achieving specimen surface morphology reconstruction. The results indicate that the multiscale model considering tiny bubbles well reveals the secondary erosion area, and the dynamic mesh coupled method better captures the erosion area compared with the method with a static mesh.