Numerical study of the hydrofoil cavitation flow with thermodynamic effects

Abstract

High-temperature water exhibits evident thermodynamic effects during cavitation, which influences the cavitation flow and generates complex flow characteristics. To reveal the mechanism of thermodynamic effects on the cavitation flow in high-temperature water, a flow around NACA 0015 hydrofoil was simulated. Based on the existing isothermal cavitation model, the thermodynamic effects were considered by correcting evaporation and condensation source terms and coupling physical parameters with temperature. Numerical results obtained from the thermodynamic effect cavitation model agree well with the available experiments. A comparative analysis of performance characteristics, cavitation shape, and interphase mass transfer rate was performed. The thermodynamic effects on the cavitation flow of hydrofoil under different temperature were presented. The existence of the thermodynamic effects lowers the local temperature of the cavitation, reduces the vapor phase volume fraction of the cavitation area, and inhibits the development of cavitation. Moreover, a novel entropy production analysis was conducted to reveal the thermodynamic effects on the energy loss. The difference of local entropy production rate in the cavitation flow with and without thermodynamic effects was revealed. The analyses show that the existence of the thermodynamic effects reduces the energy loss owing to the reduction of the dissipation loss caused by the velocity gradient. When the thermodynamic effects are considered, the energy loss caused by the temperature gradient shows an increase; however, the proportion of this loss is still small.