超声清洗过程环境压力对声空化效应的影响

The influence of ambient pressure on acoustic cavitation during the process of ultrasonic cleaning

在不同深度条件下的水下构建物超声清洗中,声空化是重要的源动力之一。为探明水下环境压力对声空化的影响,本文基于数值计算的方法,通过对超声波作用下气泡动力学的研究,讨论了环境压力对空化泡溃灭时的气泡最大半径、释放能量以及溃灭功率等因素的影响。结果表明:空化泡最大半径与环境压力在一定范围内呈近似线性关系;随着环境压力增大,空化泡释放能量和溃灭功率均显著减小,且两者在变化趋势和变化幅度上几乎一致;当环境压力大于声压幅值时,空化泡的最大半径、内部压强、内部温度与释放能量均远低于空化发生在环境压力小于声压幅值时的情形。

Ultrasonic cavitation is one of the most important sources in the application of ultrasonic cleaning for submerged structure in different depths. In order to investigate the influence of ambient pressure on ultrasonic cavitation, a numerical approach was used to study the bubble dynamics under ultrasonic operation. In this paper, the effect of ambient pressure on the maximum radius, released energy and collapsing power of cavitation bubbles was investigated. The results indicate that the relationship between the bubble＇s maximum radius and ambient pressure is approximately linear to some extent. The bubble＇s released energy and collapsing power are both significantly reduced with the increasing ambient pressure and have the same change trend in the variation of amplitude. When ambient pressure is greater than acoustic amplitude, the bubble＇s maximum radius, internal pressure, internal temperature and released energy are far below their values in the situation where ambient pressure is lower than acoustic amplitude.