Temperature inside a cavitation on a hydrofoil in hot water

Abstract

Thermodynamic effect of cavitation is a favorable effect for pumps, in which cavity volume is suppressed and suction performance of the pump is improved. When evaporation occurs in low pressure region inside the pump, local temperature is decreased by the latent heat, the local saturated pressure decreases, then the cavity is suppressed. The thermodynamic effect is known to appear when the main stream temperature closes to critical temperature of the fluid. In order to clarify the basic characteristics of the thermodynamic effect of cavitation, high temperature and high pressure water tunnel is constructed, in which the free stream temperature can be increased to 140°C. In this study, by using high accuracy measuring technique of temperature inside a cavity, temperature distribution inside a supercavitation on a hydrofoil in a hot water at 80°C and the variation of temperature depression inside a supercavitation from room temperature water at 20°C to hot water at 80 °C are measured. And the temperature depression is predicted in more high temperature region by using theoretical prediction. Additionally, through comparison of cavity length between room temperature water and hot water, the thermodynamic effect in hot water is discussed.

Keywords

• cavitation tunnel
• hot water
• thermistor
• naca0015
• cavity length