Numerical study of droplet formation in a Y-junction microchannel

This study investigates the formation process of droplets in a Y-junction microchannel using
two immiscible fluids: water as the continuous fluid and oil as the dispersed phase. We have
examined the influence of the capillary number, flow rate ratio and viscosity ratio between
the two fluids; parameters which determine the length and generation frequency of the
droplets. Numerical simulations have been performed using the software Ansys Fluent with
the interface capture method Volume of Fluid (VOF) for solving the governing equations.
Three different algorithms have been tested for the pressure-velocity coupling: SIMPLE,
SIMPLEC and PISO. The results are quite similar for SIMPLE and SIMPLEC, however
it turned out that PISO is a better algorithm to solve the two-phase flow. Additionally,
another Y-junction is coupled in the initial geometry to observe a symmetric breakup of the
droplets and their formation is explained using the pressure field and the velocity field.