Effects of Channel Length on Gas-Liquid Two-Phase Flow Phenomena in a Microchannel

An optical measurement system was used to investigate the effect of microchannel length on the characteristics of adiabatic gas-liquid two-phase flow. Experiments were conducted with a 1,676 mm long, circular microchannel with an inner diameter of 100 μm. Two-phase flow patterns, void fraction and velocities of gas plug/slug and liquid slugs were measured at different locations between the gas-liquid mixer and channel exit. The experimental values of the mean void fraction and the mean velocity of liquid slug agreed well with the homogeneous flow model predictions when the liquid flow rate was constant and the mass velocity of the gas was low. The flow pattern transition from slug flow to ring film flow was observed when the mass velocity of the gas was increased while the liquid flow rate was kept constant.