二维T型微通道内液滴生成与梯状网络内液滴相位同步问题数值模拟

Numerical simulation of the droplet generation in 2D T-junction microchannel and their synchronization in microfluidic ladder network

基于格子玻尔兹曼方法(lattice Boltzmann method,LBM)的颜色梯度模型,研究了T型微通道内液滴生成过程,分析了连续相毛细数和两相流量比对液滴生成尺寸和液滴生成频率的影响。在此基础上,研究了微流控梯状网络中两个弹状液滴相位同步问题,分析了连续相毛细数、旁通管数目和液滴初始相位长度对液滴相位同步程度的影响。计算结果表明,T型微通道内连续相毛细数和两相流量比对液滴生成尺寸和液滴生成频率有很大影响;在液滴相位同步问题上,连续相毛细数对液滴相位同步程度有较大影响,液滴初始相位长度和旁通管数目对液滴相位同步有一定程度改善,但不能实现液滴相位的完全同步。

Based on the color gradient model of the lattice Boltzmann method,the droplet generation process in the T-junction microchannel was studied in this paper.The influences of capillary number of the continuous phase and two-phase flow rate ratio on the size and generation frequency of the droplet were analyzed.The problem of the slug droplet synchronization in the microfluidic ladder network was investigated.The influential factors such as capillary number of the continuous phase,the bypass number and initial distance of the droplets were analyzed.The simulation results showed that the capillary number of the continuous phase and the two-phase flow rate ratio had a great influence on the size and generation frequency of the droplets in a T-junction microchannel.In the aspect of the droplet synchronization,the capillary number of the continuous phase affected the droplet synchronization greatly.The initial distance of the droplets and the bypass number improved the droplet synchronization to a certain degree,but the complete droplet synchronization couldn’t be achieved.