微型方直管中液滴的流动与变形

Flow and Deformation of Droplets in a Microfluidic Straight Quadratic Device

讨论了二相流体在微型管中的流动问题、边界条件与表面浸润现象，给出了微型管中二相流体的输运方程．针对方形微型管道，利用有限差分法给出了输运方程的数值求解方法．模拟了方形直管中单个和多个液滴的流动与变形过程，通过数值模拟结果发现，量纲为一的参数Pe和Ca对液滴的变形有很大影响，随着Pe的增大，液滴的变形急剧增大，当毛细数在0．35～0．50之间时，液滴尾部的曲率逐渐减小，由正值开始变成负值，形成一个凹陷．

Based on the phase-field method, the problem of two-phase flow in a micro-fluidic device and the interaction of the fluid components with a wall are discussed, and the transport equations for the two-phase flow given. Then, a numerical technique to solve equations for microfluidic quadrate devices is proposed by the finite difference method, and the numerical simulation of the flow and deformation of a droplet and multiple droplets in a cubic pipe demonstrated. It is found that the dimensionless constants Pe, Ca are important parameters, and affect the deformation of the droplet. The deformation of the droplet increases with high Pe. If the parameter Ca is between 0.35 and 0.50, the curvature at the end of the droplet decreases gradually from a positive value to negative, and become concave at the end.