Effect of Channel Wetting Properties on Flow Characteristics of Gas-Liquid Two-Phase Flow in a Microchannel

An optical measurement system and video camera were used to investigate gas-liquid two-phase flow characteristics in wetting and poorly wetting circular microchannels of 100 μm diameter. By examining the optical sensor signals from which void fraction and the lengths and velocities of gas slugs and liquid slugs were measured, the effects of wetting on the adiabatic two-phase flow characteristics of nitrogen gas and water were investigated. The data were obtained using a T-junction with the same internal diameter as the microchannel, but the T-junction itself was well wetting in both experiments. Besides the flat nose and tail of gas slugs at low gas and liquid flow rates, poorly wetting microchannel showed higher void fraction and friction pressure drop compared to the well wetting microchannel. The poorly wetting microchannel also showed the presence of short and low moving liquid slugs which were absent in well-wetting microchannel.