T型微通道中微液滴被动破裂的可视化实验研究

The Visualization Study of Breakup of Drops in T-Shaped Micro-Fluidic Devices

本文搭建了微流体实验平台,对T型微通道内微液滴的对称被动破裂进行可视化实验研究,探索微液滴破裂的机理。采用横截面为200μm×100μm或100μm×100μm的微通道,用改性硅油和花生油作为连续相,去离子水作为离散相,在毛细数为0~0.1的范围下,捕捉到了T型微通道被动破裂的隧道破裂、不连续阻塞破裂、永久阻塞破裂和未破裂等四种流型,绘制了流型图并获得了临界毛细数与微液滴的无量纲轴向长度经验关联式,用来预测不同结构及尺寸微通道发生破裂等与未破裂的条件.

In this paper,the experimental system was set up to study the symmetrical passive breakup of micro-droplet in T-shaped micro-fluidic chip.The process of the breakup of micro-droplet was observed and the mechanism was studied.In the experiment,the cross section of the micro-channel is 200 μm×100 μm or 100 μm×100 μm Silicone oil and peanut oil were used as continuous phase,while deionized water was used as dispersed phase.For Ca number ranging from 0 to 0.1,four types of droplets' symmetrical breakup,breakup with tunnels,breakup with discontinuous obstruction,breakup with permanent wall obstruction,non-breakup were captured.Finally,the phase diagram was drawn and empirical correlations about critical Ca number and the non-dimensional length of micro-droplet were obtained to predict the conditions of weather the micro-droplet will breakup in different structure and sizes of micro-fluidic chips.