Effect of Geometry Configuration on the Merged Droplet Formation in a Double T-Junction

摘要

The merged droplets have great practical application value in protein synthesis and crystallization. In this paper, the effect of geometry configuration on the merged droplet formation in a double T-junction microchannel is studied by three-dimensional numerical simulation using the level-set method. There are three important parameters in the geometry configuration of the microchannel, namely angle between two phases (alpha), height-to-width ratio (Lambda= H/w(c)), and intersection width ratio (Gamma=w(d)/w(c)). In this study we found that a critical value of the two-phase angle is 60 degrees. When the angle is 60 degrees, the effective diameter of the merged droplet is the smallest and the generation frequency is the fastest under the same physical condition. We found that height-to-width ratio and intersection width ratio have a critical value of 1.0. When height-to-width ratio or intersection width ratio is 1.0, the shearing capacity of the continuous relative dispersed phase reaches a maximum, thus the droplet diameter is minimized and the frequency is the fastest. Therefore, reasonable adjustment of these three factors is an effective method to solve the problem of the high-throughput monodispersemerged droplet formation. This work lays a solid theoretical foundation for the merged droplets in practical applications.