微通道内气液Taylor流网格局部加密数值模拟

Numerical study of the gas-liquid two-phase Taylor flow in micro-channels with the local mesh encryption

采用VOF模型和局部非均匀加密的网格划分方法对交错T型微通道内Taylor流进行了数值模拟。模拟结果表明,较之常见的均匀加密方法,局部非均匀加密方法使得计算时间节省,并且实现了对气液两相界面的精确捕捉,利于后期的对液膜厚度对传热等方面的数据处理分析。此外,还研究了接触角和毛细管数对流型的影响。θ<90°时,气泡和液柱长度与接触角呈凹函数关系,但总体影响较小。但当θ>90°时气泡生成周期会明显增大。同时,通过观察液膜还发现毛细管数越大液膜越厚。

This paper simulated the gas - liquid two phase Taylor flow pattern in a staggered T - junction micro - channel u- tilizing Volume of Fluid （VOF） model and local mesh non- uniform encryption method . The results suggested that the calcula- tion time had saved comparing with uniform encryption method. Simultaneously, the paper caught the gas - liquid two phase in- terface accurately using the method. In addition, this paper studied the influence of contact angle and Capillary number change to flow pattern. There exists concave function between contact angle and the length of the bubble and liquid column. Especially, bubble generation cycle saw a significant increase when θ〈90°. We also found the capillary number is proportional to the thick- ness of liquid film.