空泡在T型微通道中的分裂特性

Breakup Characteristics of Bubble Moving in T-Junction Micro-Channel

在不同流速下通过精确控制空气和水的入口速度比,获得了不同体积的空泡.借助高速摄像系统记录产生的空泡在T型微通道分岔处分裂的全过程,并采用计算流体动力学对空泡运动过程进行数值模拟.分析了空泡体积和流场速度对空泡分裂特性的影响,从而得出空泡分裂的判据.结果表明:空泡在T型微通道中的分裂包含5种方式,与流场速度和空泡体积相关—流场速度越大,空泡体积越小,空泡发生分裂越剧烈;微通道尺度越小,流体黏性、表面张力以及流速对空泡分裂特性的影响越显著.

Under different flow field velocities, bubbles with different volumes were gained by accurate control of inlet velocity of air and water. The breakup process of the generated bubbles in T-junction mi- cro-channel was recorded by high-speed imaging system. In addition, computational fluid dynamics was used to simulate the breakup process of bubble. The criterion of estimating the bubble breakup was ob- tained. The results show that the bubble breakup contains five major modes in T-junction micro-channel, depending on flow field velocity and bubble volume. The higher the flow field velocity and the smaller the bubble volume, the more intense the bubble breakup. The effects of fluid viscosity, surface tension and flow field velocity on bubble breakup become more significant for smaller micro-channel.