考虑水蒸汽蒸发和冷凝的超声空化特性研究

Characteristic Research on Ultrasonic Cavitation Bubbles Considering the Evaporation and Condensation of Water Vapor

超声空化泡在溃灭时能够产生局部高温高压等极端物理化学效应。今在现有超声空化理论的基础上,考虑了水蒸汽的蒸发和冷凝效应,建立了超声空化动力学方程。文中采用数值方法,模拟了超声空化气泡运动状态参量变换规律。结果表明,不考虑水蒸汽的蒸发冷凝时,气泡在溃灭时最高温度和最大压力分别为27944 K和9.9072 GPa;而考虑水蒸汽的蒸发冷凝时,其最高温度和最大压力分别为3303.7 K和2.2342 GPa。因此水蒸汽的蒸发和冷凝对超声空化过程具有不可忽略的影响。

As a cavitation bubble collapse, extremely physical and chemical environments of thousands of degrees and thousands of atmospheres are generated within the bubble. In this paper, based on the dynamic equations of ultrasonic cavitation considering evaporation and condensation of water vapor, we study the impact of evaporation and condensation of water vapor on the ultrasonic cavitation characteristics by using Numerical Simulation Methods. The result shows that when without considering evaporation and condensation of water vapor, the maximum temperature and maximum pressure inside the bubble are 27944 K and 9.9072 GPa respectively; while considering the evaporation and condensation of water vapor, the maximum temperature and maximum pressure within the bubble are 3303.7 K and 2.2342 GPa respectively. So evaporation and condensation of water vapor have a great influence on the ultrasonic cavitation and are not able to be neglected.