Experimental Study and Numerical Simulation for Sediment’s Promoting Effect on Cavitation Based on Flow Field Analysis

Sediment-laden water significantly exacerbates cavitation damage in hydraulic machinery compared to clear water, underscoring the importance of investigating the effects of sediment on cavitation. This study examines cavitation in sediment-laden water using a Venturi flow channel and a high-speed camera system is utilized to capture the morphology and evolution of cavitation clouds. Natural river sand samples with a median diameter of 0.05, 0.07, and 0.09 mm are selected, and sediment-laden water with a concentration of 10, 30, and 50 g/L is prepared for the study. The results indicate that increasing sediment concentration or reducing sediment size intensifies cavitation, shortens the evolution cycle of cavitation clouds, and elevates the frequency of cavitation cloud shedding. Meanwhile, numerical simulation is conducted based on a gas-liquid-solid phase mixing model. The findings indicate that a higher sediment concentration corresponds to a greater shear effect near the wall, which raises the drag on the attached sheet-like cavitation clouds and enhances the re-entrant jet which can intensify the shedding of cavitation clouds. Furthermore, sediment particles contribute to more vortex: they enhance the impact on smooth, wall-adjacent sheet-like vortex, while simultaneously consuming more energy during the vortex return process, resulting in the creation of additional small-scale vortices.