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.