Phase split characteristics of slug and annular flow in a dividing micro-T-junction

The characteristics of slug and annular gas-liquid two-phase flow when moving through a rectangular micro-channel dividing T-junction were investigated with experiments focusing on the relationships between the phase split and the two-phase superficial velocity, liquid surface tension, and liquid effective viscosity. The effects of the pipe sizes and pipe cross section shapes on phase split were compared and analyzed. Phase split was tested using a 100 × 800 μm rectangular dividing micro-T-junction. Air was used as the gas medium and the liquid mediums were water, 0.01% SDS solution, 0.5% SDS solution, 0.1 wt% PAAm, 0.25 wt% PAAm, and 0.5 wt% PAAm. Results showed that whether the inlet flow pattern was slug or annular flow, the liquid taken off from side branch at the dividing T-junction decreases with an increase in liquid superficial velocity and that there is little effect of inlet gas flow rate on the liquid taken off. It was also found that the liquid taken off from side branch decreases with a decrease in liquid surface tension and increases with an increase in liquid effective viscosity. When results were compared to those from studies using channels of other diameters, it was seen that the phase split of the slug flow was similar at different sized dividing T-junction, while the phase split of annular flow varied at different pipe sizes. It was also seen that the phase split characteristics of a dividing micro-T-junction are dependent on the aspect ratios of the channel's cross section. A predictive model of phase split characteristics studied in this investigation was formulated with the regression analysis of the experimental data and verified by calculations showing little error.