Phase split of gas–non‐Newtonian fluid two‐phase flow in a ψ‐shaped branching microchannel

Abstract An experiment of phase split was conducted in a horizontal ψ‐shaped branching microchannel to study the phase distribution and pressure drop at the bifurcation. The pressure drop at the test section and the flow rates of the gas and liquid phases through the three branches were measured. The pressure drop gradients at the inlet and branches were predicted by the correlation based on the separated flow model. The critical condition for the split of the two‐phase flow was determined. The results showed that the gas phase separated from the side arm was more than the liquid phase. A uniform distribution could be achieved for the churn flow in water. Pressure drop occurred at the bifurcation of the side arm under the effect of the vortex in the liquid slug near the bubble nose; the pressure drop was much greater than that at the bifurcation of the run.