采用计算流体力学(CFD)方法，对宽型微米级T-型微通道中微液滴形成机制进行了数值模拟。通过与已有文献实验结果的对比，证明了数值模拟的准确性；发现液滴在微通道中的形成过程可分为液滴形成和成长、液滴与分散相的脱离和液滴从通道壁的脱落3个阶段。首次系统分析了通道壁的润湿性对液滴形成的影响，发现当分散相在通道壁上的接触角小于90°时，才能形成微液滴；通道壁越疏分散相，微液滴越容易形成，并且从通道壁上脱离的时间也越短。通过分别改变连续相的黏度、流速以及两相间界面张力，研究了毛细准数Ca对微液滴的形成机制及液滴大小的影响。发现在T-型通道中能形成液滴的范围内，Ca越大，则形成的微液滴体积越小；当Ca大于0.067时，微液滴的直径与连续相Ca的倒数之间存在明显的线性关系。

Droplet formation in a microfluidic T-junction is simulated by using computational fluid dynamics (CFD) method. The accuracy of CFD study is verified by comparing the simulation result with the experimental results in literatures. It is found that the formation of droplets in the T-junction can be divided into 3 steps: droplet emergence and growing up, separation with the dispersed phase, and detachment from the channel wall. The study on the wetting property of the channel wall shows that it has a remarkable influence on the droplet formation. Only when the contact angle of the dispersed phase on the wall is smaller than 90°, the droplets can be formed. Moreover, the wetting property of the channel significantly affects the detachment time of the droplets from the wall. The effect of the capillary number, Ca, on droplet formation is studied by varying the viscosity, and velocity of the continuous phase or the interfacial tension, respectively. In the range that the droplets can be formed, the droplet size decreases with the increase of Ca，and when Ca is bigger than 0.067, droplet diameter shows an obvious linear relationship with 1/Ca.

重庆市自然科学基金资助项目(CSTC,2008BB0059)；教育部留学人员回国启动基金资助项目(教外司留(2009)8-1)；中央高校基本科研业务费科研专项“研究生科技创新基金”资助项目(CDJXS10221140，CDJXS11221169)；中央高校基本科研业务费资助项目(CDJXS10220006)