Numerical investigation of gas–liquid slug formation in T-junction microchannel using OpenFOAM

Gas–liquid two-phase flow in a T-junction microchannel was investigated numerically. The computational fluid dynamics (CFD) model was developed using OpenFOAM and the volume of fluid (VOF) method. The CFD model was validated by comparing the results with the available data in the literature. Air and water superficial velocities were 0.01–0.25 m/s and 0.025–0.5 m/s, respectively. Three flow regimes (squeezing, dripping, jetting) were observed. The contribution of pressure in the bubble formation stages was investigated by monitoring the temporal variation of pressure. The effect of geometry was investigated by studying the impact of the diameter ratio between the dispersed and continuous phase channels. Five different contact angles θ at 0°, 30°, 60°, 90°, and 110° were chosen to study the effect of wall adhesion on the bubble size, shape, and detachment time. Finally, the impact of contact angle with various Capillary number and diameter ratio on bubble length was investigated.