小曲率蛇形微通道弯头处弹状流流动及传质特性的数值研究

采用CLSVOF（coupled level set and volume of fluid）方法，以空气和水为工作流体对小曲率矩形截面蛇形微通道内气液两相流动进行模拟研究。验证模型的合理性后，研究了曲率对弯通道内压降的影响，曲率及气相速度对弹状流气泡及液塞长度的综合影响；同时深入分析了弯管内气液两相流动的传质特性，包括不同曲率下气泡长度的变化，弯管内液侧体积传质系数与液膜体积传质系数的比较，曲率及气相速度对液相体积传质系数的影响。同时，对比了回转弯道与直微通道传质系数的差异，发现弯微通道可以强化传质。

Numerical simulation on gas-liquid flow and mass transfer in curve part of serpentine micro-channel with small curvature

A numerical analysis of flow pattern in a serpentine microchannel with small curvature and rectangular cross-section was made using the CLSVOF(coupled level set and volume of fluid method) multiphase model.The gas and water were used as working fluids.After verifying the rationality of the model with the experiment, the effect of curvature on the pressure drop in curved microchannel was studied, the combined influence of curvature and gas velocity on bubble and liquid slug length were investigated.At the same time, the mass transfer characteristics of gas-liquid two-phase flow in curve microchannel were analyzed deeply, including the change of bubble length under different curvature, and comparison of liquid volumetric mass transfer coefficient and mass transfer coefficient of liquid film in curve microchannel.Also, effect of curvature and gas phase velocity on liquid phase volumetric mass transfer coefficient was observed.Meanwhile, the difference of mass transfer coefficient between the curve and straight microchannel was compared, which leaded to a conclusion that the curve micro-channel can enhance the mass transfer.