Numerical modeling and experimental investigation of gas–liquid slug formation in a microchannel T-junction

Abstract

Gas-liquid two-phase flow in a microfluidic T-junction with nearly square microchannels of 113 μm hydraulic diameter was investigated experimentally and numerically. Air and water superficial velocities were 0.018-0.791 m/s and 0.042-0.757 m/s, respectively. Three-dimensional modeling was performed with computational fluid dynamics (CFD) software FLUENT and the volume-of-fluid (VOF) model. Slug flow (snapping/breaking/jetting) and stratified flow were observed experimentally. Numerically predicted void fraction followed a linear relationship with the homogeneous void fraction, while experimental values depended on the superficial velocity ratio U G /U L . Higher experimental velocity slip caused by gas inlet pressure build-up and oscillation caused deviation from numerical predictions. Velocity slip was found to depend on the cross-sectional area coverage of the gas slug, the formation of a liquid film and the presence of liquid at the channel corners. Numerical modeling was found to require improvement to treat the contact 2 angle and contact line slip, and could benefit from the use of a dynamic boundary condition to simulate the compressible gas phase inlet reservoir.

Spurious Current Suppression in VOF-CSF Simulation of Slug Flow through Small Channels

“…3c) which are pertinent to micro-reactor systems [5][6][7][8] and heat transfer [18,19,[23][24][25][26].…”

“…Liquid-gas slug flow in small capillary tubes and microchannels is important in heat transfer applications [1][2][3][4], micro-reaction systems [5,6], and microfluidic control [7,8]. Bretherton [9] pioneered theoretical analysis of single bubble motion in a rigid round channel under a lubrication assumption that at low Capillary numbers, viscous forces only affect the static interface profile near the wall.…”

Comparison of experimental data and numerical simulation of two-phase flow pattern in vertical minichannel

“…In the literature a lot of work on numerical calculations of two-phase flows in micro-and minichannels has been published. As an example one can cite the work of (Gupta et al, 2009;Pohorecki and Kula, 2008;Qian and Lawal, 2006;Santos and Kawaji 2010). An analysis of the literature shows that numerical simulation of a two-phase flow in a minichannel can be achieved by developing one's own prediction model (Pohorecki and Kula, 2008) or using commercial software (Gupta et al, 2009;Qian and Lawal, 2006;Santos and Kawaji, 2010).…”

“…As an example one can cite the work of (Gupta et al, 2009;Pohorecki and Kula, 2008;Qian and Lawal, 2006;Santos and Kawaji 2010). An analysis of the literature shows that numerical simulation of a two-phase flow in a minichannel can be achieved by developing one's own prediction model (Pohorecki and Kula, 2008) or using commercial software (Gupta et al, 2009;Qian and Lawal, 2006;Santos and Kawaji, 2010). Pohorecki and Kula (2008), Qian and Lawal (2006) made a numerical simulation of two-phase flow in a minichannel in two dimensions, while Santos and Kawaji (2010) used a three-dimensional geometry to make calculations.…”

“…An analysis of the literature shows that numerical simulation of a two-phase flow in a minichannel can be achieved by developing one's own prediction model (Pohorecki and Kula, 2008) or using commercial software (Gupta et al, 2009;Qian and Lawal, 2006;Santos and Kawaji, 2010). Pohorecki and Kula (2008), Qian and Lawal (2006) made a numerical simulation of two-phase flow in a minichannel in two dimensions, while Santos and Kawaji (2010) used a three-dimensional geometry to make calculations. Among the commercial software, one of the most commonly used is ANSYS FLUENT (Gupta et al, 2009;Qian andLawal 2006, Santos andKawaji 2010).…”