Modeling of droplet breakup in a microfluidic T--shaped junction with a phase--field model

TL;DR

This paper uses a phase-field model to simulate droplet breakup in a microfluidic T-junction, accurately capturing experimental phase diagrams and analyzing how flow parameters influence breakup.

Contribution

It introduces a three-dimensional phase-field simulation approach to model droplet breakup in microfluidic T-junctions, aligning well with experimental observations.

Findings

Model reproduces experimental phase diagram.

Critical capillary number depends on viscosity contrast.

Flow rate and surface tension influence droplet breakup.

Abstract

A phase--field method is applied to the modeling of flow and breakup of droplets in a T--shaped junction in the hydrodynamic regime where capillary and viscous stresses dominate over inertial forces, which is characteristic of microfluidic devices. The transport equations are solved numerically in the three--dimensional geometry, and the dependence of the droplet breakup on the flow rates, surface tension and viscosities of the two components is investigated in detail. The model reproduces quite accurately the phase diagram observed in experiments performed with immiscible fluids. The critical capillary number for droplet breakup depends on the viscosity contrast, with a trend which is analogous to that observed for free isolated droplets in hyperbolic flow.