关键词: 微通道, 可视化, 液-液两相流, 流型

Abstract: High speed digital camera was employed to investigate the liquid-liquid two-phase flow behavior in a double T-type microchannel with a rectangular cross-section， a hydraulic diameter of 0.176mm and an aspect ratio of 2.4. By changing the volumetric flow ratios of silicon oil （continuous phase） and water （dispersed phase），the two-phase flow pattern as well as the flow evolvement process were recorded and analyzed. At the upstream T-junction of the microchannel，the droplet，slug，wavy parallel，and parallel flow were observed. At the middle zone of the microchannel，a flow pattern map was presented on the basis of Weber numbers of water and oil. In addition，linear relationships between the dimensionless length of slug/droplet and water/oil flow ratios were established. Also，it was found that the velocity of slug/droplet was larger than the two-phase mixture superficial velocity，and a correlation for well predicting the velocity of slug/droplet was developed. Finally，droplet behaviors at the downstream T-junction of the microchannel were investigated，and two different flow modes，breaking and non-breaking were observed and analyzed. Corresponding two different regimes of breakup were singled out as well.

Key words: microchannel, visualization, liquid-liquid two-phase flow, flow pattern