Numerical investigation of mass transfer behavior of a gas–liquid two-phase Taylor flow in a microchannel by a volume-of-fluid multiphase flow system

The microchannel reactor is the most commonly used microreaction technology, an innovative reaction system developed in recent years. This study investigates the mass transfer behavior of a gas–liquid two-phase Taylor flow in a microchannel by coupling the volume-of-fluid model and the species transport model. The concentration distribution and the volumetric mass transfer coefficient of the gas solute are determined and discussed in detail. The simulation results reveal that the double-circulation flow influences the concentration distribution in the liquid slug. The highest value is observed at the bubble's surface and decreases rapidly along the vertical direction of the bubble. The increase of bubble velocity leads to a more apparent decreasing trend. The gas–liquid interface renewal rate of the bubble is accelerated with increasing bubble velocity, resulting in an increase in the average mass transfer rate in all regions of the bubble surface with an increase in bubble velocity. The results also indicate that the liquid film area contributes the most to the mass transfer behavior due to the most significant proportion and average mass transfer rate of the liquid film among the bubble.