【作者】 李林；

【导师】 朱家骅；

【作者基本信息】 四川大学 ， 化学工艺， 2006， 硕士

【摘要】 超声波作为一种能量形式在液体中所引起的超声空化,以及空化气泡与液相相互作用而产生的各种效应己在物理、化学、生物等学科的基础研究和应用技术开发中展示出十分广阔的前景。超声空化是一个极其复杂的过程。空化气泡在超声波的作用下,膨胀、收缩、再膨胀、再收缩,多次周期性振荡直至崩裂,从而引发许多物理、化学效应,如破坏生物组织,加快化学反应速度,产生光辐射等。因此,超声场下空化气泡的形成及运动的研究具有十分重要的理论基础和实际应用意义。本文依据空化气泡在超声波的作用下,膨胀、收缩的运动规律,把气泡看作为一个以液体为负载的振子,沿用Rayleigh方程推导方法,由能量守恒推导出多参数下空化气泡壁的运动方程。利用Matlab进行程序编写对方程进行了模拟求解并探讨了各因素对超声空化的影响。计算结果表明:超声频率变大,空化泡的振幅变小,不利于声空化;随着声压幅值的增加,空化泡的运动加剧,利于声空化;低黏度液体中空化效果更好;低的大气压利于声空化;气泡直径小于或等于共振尺寸时利于声空化;较低的气泡内压利于声空化;气体导热系数小空化效果更好。数值模拟结果证明:超声波功率、气泡内压、气泡直径对空化气泡的运动影响较大。本文进一步探讨了超声场对传质过程的强化。依据液体“格子”模型推导了超声场作用下溶液中溶质扩散的分子动力学模型的修正式,探讨了超声强对液相粘度和扩散系数的影响。分析结果表明:超声场的引入使得溶剂分子要受到更多还原

【Abstract】 The acoustic cavitation in the liquid due to the ultrasonic which effecting in a energy form and a lot of effects by the reciprocity of the cavitation bubble and the liquid has been applied in many fields, such as physics, chemistry, biology, etc.. It has a great future in these basic research and application technologies. The acoustic cavitation is a very complex process. The generation, growth and collapse of the of the cavitation bubble due to the ultrasonic could arouse many physical and chemic effects such as accelerating the chemic reaction, destroying the biologic organization, generating the luminescence etc.. Therefore, the research of the generation and the motion of the cavitation bubbles are very important.According to the cavitation bubble motion regulation of the generation, growth and collapse of the cavitation bubble; this investigation regards a cavitation bubble as a bob, which is filled with liquid. This investigation has detruded the cavitation bubble motion equation by the method of Rayleigh equation. A numerical simulation on the cavitations bubble motion was done employing by Matlab and the influence on the acoustic cavitations of many correlative parameters was discussed. It was founded that with the decreasing of ultrasonic frequency the amplitude of cavitations bubbles decreased, which made against for cavitation. Meanwhile with the increasing of acoustic pressure the motion of cavitation bubbles was enhanced, which was in favor of acoustic cavitation. It showed that with lower liquid viscosity, lower更多还原