超声对近壁微气泡溃灭过程的影响*

近壁微气泡溃灭特性的深入研究对靶向给药和基因治疗等技术具有较好的指导作用。该文基于数值模拟技术,采用有限体积法结合流体体积模型对超声作用下的近壁微气泡溃灭特性进行了研究,分析了超声对近壁微气泡溃灭动力学过程的影响。结果表明气泡溃灭最大射流速度与近壁距离无量纲参数在1.1~1.6范围内时成正比,与超声频率在10~60 Hz范围内时成正比,与气泡初始半径在50~100μm范围内时成反比;近壁气泡的二次溃灭最大射流速度大于一次溃灭,二次溃灭的作用更加明显。超声参数对近壁气泡溃灭过程存在较大影响,该研究为超声在医学上的应用提供了依据。

The effect of ultrasound on the collapse of near-wall microbubble

Deep understanding of the characteristics of near-wall microbubble collapse has an important influence on targeted drug delivery and gene therapy. Based on the numerical simulation, the finite volume method together with the Volume Of Fluid (VOF) model were carried out to investigate the characteristics of near-wall microbubble collapse. The effect of ultrasound on the collapse process is studied in detail. The results show that the maximum jet velocity of microbubble is proportional to the distance and the ultrasonic frequency, but inversely proportional to the initial bubble radius. The maximum velocity of bubble second-collapse is larger than that of the first collapse, which means the impact of the second-collapse is more important. In this paper, the mechanism of near-wall microbubble collapse under ultrasonic field is further revealed, which provides a basis for ultrasonic application in medical treatment.