Numerical simulation of droplet formation in a Co-flow microchannel capillary device

In this article, a numerical simulation of the droplet formation in a Co-flow microchannel capillary device, and the influencing factors of the formation of droplets are studied. The level set method is used to track the two-phase interface and droplet formation. In the Co-flow focusing device, we explored the influencing factors of the size of the generated droplets. In the Co-flow focusing device, we explored the influences of various factors on the droplet size, generation frequency, and the droplet pressure at the centerline. The results demonstrate that an increased ratio of dispersed phase velocity to continuous phase velocity leads to a significant increase in the volume of generated droplets, a significant decrease in droplet generation frequency, and a significant decrease in droplet pressure at the centerline. Furthermore, as the viscosity of continuous phase increases, the volume of generated droplets decreases significantly, the frequency of droplet generation increases significantly, and the pressure of droplets at the centerline decreases significantly. Additionally, an elevated contact angle between the continuous phase and the wall results in a slight increase in the volume of generated droplets, alongside a reduction in droplet generation frequency and a decrease in droplet pressure at the centerline. Moreover, with the increase in interfacial tension, there is a significant increase in the volume of droplet generation, a significant decrease in the frequency of droplet generation, and a significant increase in the pressure of droplets at the centerline.