A simplified thermodynamic effect model for cavitating flow in hot water

Abstract

When cavitation occurs, under the evaporation cooling effect, the local temperature decreases, saturated vapor pressure decreases, then cavitation is suppressed. This is known as “thermodynamic effect” of cavitation, which is normally neglected in water cavitation at room temperature. Due to the low liquid-vapor density ratio, the thermodynamic effect becomes much more important and cannot ignore in hot water cavitation. Therefore, in numerical simulation, the thermodynamic effect needs to be taken into account. This study, a simplified thermodynamic model, which has been applied to liquid nitrogen cavitation, combining with our cavitation model is extended to hot water cavitation. The cavitation experiment on a 2-D triangle cylinder in the water at 90°C is conducted. The temperature depression in cavity under thermodynamic effect is measured by using the thermistor probe. Then, experimental data is used for validating the present simplified thermodynamic model. Furthermore, the present model is extended to cryogenic cavitation. The numerical result shows good agreement in cavity volume and temperature comparison with experiment in the present hot water and cryogenic liquid.