关键词: 气液两相流, T形微通道, 相分离

Abstract: Using air as gas working fluid and with liquids of different surface tensions （pure water，0.01% SDS solution，0.5% SDS solution，ethanol） as working fluids，a visualization experiment was conducted to study the split of annular flow through a T-junction with a rectangular cross section （100 μm×800 μm）. The results showed that the liquid preferentially enters the side branch. Liquid taken off mainly concentrated in 0.25—0.65 and gas taken off mainly concentrated in 0.1—0.8. The rate of increase of liquid taken off become bigger with increase of gas taken off. It was found that the liquid taken off of annular flow decreases with an increase of superficial liquid velocity at a certain superficial gas velocity. When the superficial liquid velocity is certain，there is very little effect of inlet gas flow rate on the liquid taken off. We also found that the decrease in liquid surface tension make the liquid taken off increase. When the present data were compared to those from other diameter junctions，it is seen that the phase split characteristics of the annular flow is very dependent on pipe size.

Key words: annular flow, micro-T-junction, phase splitting