Droplet behavior and its effects on flow characteristics in T-junction microchannels

Abstract

The single-phase flow and droplet flow are investigated in a rectangular microchannel with a T-junction, through experiments and simulations to improve the understanding of a droplet flow and its effect on overall flow in channels with junctions. Droplet behavior can be divided into three modes: flow into the side branch, a split at the junction, and flow into the downstream channel. In branches of the junction, the flow rate ratio and the pressure difference are affected by droplets with the same flow behavior flowing in the junction. The change in the volumetric flow rate ratio and pressure difference between two channels also depend on droplet size and flow conditions. Furthermore, the length of the droplet affects whether the droplet splits at the junction, and this behavior can be documented by a power law relationship between the capillary number Ca and droplet length.