A review of two-phase gas–liquid adiabatic flow characteristics in micro-channels

A literature review of recent research on two-phase flow in micro-channels is provided in this article. Researches on the micro-hydrodynamics concerned with two-phase gas–liquid adiabatic flow characteristics in both circular and non-circular micro-channels are discussed. This review aims to survey and identify new findings obtained from this attractive area, which may contribute to optimum design and process control of high performance miniature devices comprising extremely small channels. The results obtained from a number of previous studies show that the flow behaviors in the micro-channels deviate significantly from those in ordinarily sized channels. A clear understanding of the flow behaviors encountered is necessary to answer the fundamental questions related to the two-phase flow phenomena. Similar to the ordinarily sized channels, it is expected that the flow pattern, pressure drop and void fraction will influence the two-phase pressure drop, holdup, system stability, exchange rates of momentum, heat and mass during the phase-change heat transfer processes. It is obvious that publications available on micro-channels are relatively small compared to those for ordinarily sized channels and further systematic studies of two-phase gas–liquid adiabatic flow in micro-channels are required.