Numerical investigation on the evolution of cavitating dynamics and energy loss around a hydrofoil in fluoroketone under different temperatures

Abstract

To investigate the effects of variable free-stream temperatures on cavitation evolution and entropy production in fluoroketone cavitation flows. The Zwart cavitation model with the thermodynamic effect and the modified RNG k-ε turbulent model with the compressibility of the gas-liquid mixed phase are used to run the simulation. Numerical results demonstrate that the intensity of cavitation decreases as free-stream temperatures rises, resulting in the cavitation thermal effect. Because cavitation shedding caused a negative pressure gradient, the main flows on the hydrofoil pressure surface at the trailing edge went back along the suction surface. The re-entrant at the trailing edge is caused by the interaction between returned flows and the process of cavitation growth. The process of cavitation interphase mass transfer alters the internal temperature field. In addition to the local temperature decrease induced by evaporation, condensation causes a local temperature increase. And, evaporation is more intense than condensation. The entropy production caused directly by temperatures is very small, and primarily caused indirectly by the velocity pulsation in the flow field. This study could help to comprehend the unsteady cavitation flow in fluoroketone while accounting for the thermodynamic effect, as well as the rational design of fluid machinery for transporting thermo-sensitive fluids.