A comprehensive review on liquid–liquid two-phase flow in microchannel: flow pattern and mass transfer

Liquid–liquid two-phase flow in microchannel is very common in micro-chemical and micro-biological system, etc. Deep understanding of the liquid–liquid two-phase flow mechanisms and mass transfer in microchannel can promote industrial applications significantly. To summarize the recent research progress on the liquid–liquid two-phase flow in microchannel, this paper collects research work about this topic, especially focusing on flow pattern and mass transfer. To begin with, flow patterns observed in various conditions are identified and factors which influence the flow patterns are analyzed. Then, mass transfer in liquid–liquid two-phase flow is discussed, especially the mass transfer during droplet flow, with both experiments and simulations. Furthermore, energy dissipation involved in liquid–liquid two-phase flow in microchannel is also briefly discussed. Finally, future needs are proposed for extending the researches on liquid–liquid two-phase flow and enlarging its application fields.