T-型微通道中液滴形成机制的CFD模拟

CFD simulation of droplet formation in microfluidic T-junction

对微米级窄型T-型微通道中微液滴的形成机制进行了CFD模拟,验证了随毛细准数Ca的增加,液滴的形成会经历"squeezing"和"dripping"机制,且2个机制之间明显的存在着一个"transient"机制。通道壁的润湿性能对液滴的形成过程有显著影响,只有当通道壁更亲连续相时,微液滴才能形成。但与"dripping"机制不同,在"squee-zing"机制下,通道壁的润湿性对形成液滴的体积有明显的影响。

Droplet formation in a narrow-type microfluidic T-junction was simulated using the CFD package, FLUENT. The results confirm that with an increase in the capillary number, the drop formation in the T-junction investigated experiences the ＂ squeezing＂ and ＂ dripping＂ regimes successively, and between them, a ＂ transient＂ regime obviously exists. Under both the two regimes, the wettability of the channel wall has a significant influence on the droplet formation. Droplets can be formed only when the continuous phase fluid preferentially wets the channel wall, and on the contrast to the ＂dripping＂ regime ,the wettability of the channel wall significantly affects the drop size in the ＂squeezing＂ regime.