Study of the Hydraulic Characteristics of Slug Flow in the Microfluidic Y-shaped Junctions of Three Different Cross Angles

Abstract The slug flow in microchannels has been applied for microdroplet/bubble production in recent years. The comparison investigation of hydrodynamic properties of slug flow in three different Y-shaped microchannels was conducted by numerical methods. The numerical simulation results show that the VOF model can describe the velocity and pressure field in the Y-shaped microchannel. It was found that the pressure in the microchannel from upstream to downstream showed an overall decreasing trend, and the liquid phase pressure between the two gas slugs was less than the internal pressure of the adjacent gas slug. The midline pressure of the bubble generation moment is less than the rest of the state. Among the three Y-shaped junctions, the absolute value of the pressure difference at the moment of slug bubble formation is the smallest when the angle of the Y-junction is 90°. Compared to 120° and 90° Y-junctions, the pressure and velocity field of the 60° Y-junction is the most unstable when the slug flow generates.