Effect of solid particle size on cavitation around hydrofoil

Abstract

Pumps and turbines are widely used in marine engineering, and hydrofoil cavitation, a fundamental form of pump and turbine cavitation, is often used as a simplified hydraulic model to study cavitation issues. However, oceans and lakes contain many particulate impurities that can exacerbate the instability of the cavitation flow field around hydrofoils. Currently, there are few studies on solid particle-induced cavitation in hydrofoils. To investigate the influence of small particles on blade cavitation, the National Advisory Committee for Aeronautics 0006 hydrofoil was used as a simplified blade model. Using the large eddy simulation-volume of fluid method and the discrete phase model, the three-dimensional cavitation flow field around the hydrofoil was analyzed for nine different particle sizes at a 3% particle concentration and compared to the flow field in clean water. The results show that small particles cannot penetrate the bubble film but move along the surface of the cavity, slightly increasing the vortex and turbulence intensity within the cavitation flow field, thereby promoting cavitation development and reducing the hydrofoil's hydrodynamic performance. As particle size increases, the overall effect of particle number becomes stronger, while the reduction of particle number leads to a reduced impact of small particles on the cavitation flow field.