Microfluidics relies on droplet formation in cross-shaped micromixers to regulate chemical processes, material creation, and biological testing. These devices form droplets via shear forces and interfacial tension at a perpendicular junction of two immiscible fluids. As the continuous phase runs along the main channel, a side arm introduces the dispersed phase, forming droplets at the junction. Based on the reference paper [ Mixing Efficiency Analysis on Droplet Formation Process in Microchannels by Numerical Methods ], the CFD simulation is conducted.

Simulation Process

The cross-shaped junction is primarily designed using Design Modeler. Then, a structured grid discretized the computational domain into X distinct cells. The simulation is executed using the Volume Of Fluid (VOF) approach. The VOF Multiphase approach can accurately conduct liquid-liquid two-phase flow in microchannels and is capable of transient tracking on the liquid-liquid/gas interface.

Post-processing

Diffusion dominates mixing in microfluidic devices, making it exceedingly challenging to attain an acceptable mixing efficiency. The use of droplet-based methods to solve this issue is becoming more and more popular. The dispersed phase becomes smaller droplets due to the interaction of the two phases when they are injected into the microchannel; this restricts the mixing process inside the droplet. The mixing performance may be greatly boosted by the shortened diffusion distance and improved internal circulation inside droplets. This formation process is perfectly portrayed in the animation.