Numerical investigation of the effect of microfluidic flow parameters and physical properties on double emulsion droplet forming

The preparation of double emulsion droplet is a significant development direction in droplet microfluidics. In this paper, we simulate the droplet formation inside a six-way type microchannel. The effects of flow rate, viscosity, and interfacial tension of microfluid on the process of droplets preparation are investigated, i.e., the forming quality of droplets under different flow parameters and physical properties of microfluid, which is of reference significance for the preparation of microdroplets such as double emulsion droplet. In this paper, it is found that when the flow rate of the outer phase increases, the area of the inner and outer droplets of double emulsion droplets decreases; when the flow rate of the middle phase increases, the area of the inner droplet decreases, while the area of the outer droplet increases; the viscosity affects the forming flow pattern, and the location where the area ratio of inner and outer droplets changes more intensely is near the flow pattern transition node; the interfacial tension has a significant influence on the forming size of droplets.