Characteristics of liquid-liquid two-phase flow in a constructal honeycomb reactor

Inspired by the bionic structure, a honeycomb network was designed according to Bejan's Constructal theory and manufactured via 3D-printing. The flow characteristics of the liquid–liquid system with an extremely low viscosity ratio (λ ~ 0.001) were investigated. Typical dumbbell-like plugs were observed and the evolution of their forms in the straight channel was presented. The overall flow status in the honeycomb network was classified into three types, namely, asymmetrical flow, symmetrical flow, and sphere flow. The uneven breakup of mother droplet at the Y-junction of part 2, which caused the final uniformity of droplets distribution, was attributed to the feedback from unbalanced flow resistance of downstream channels. The competition behaviors of the droplet pair, including squeezing, splitting and no-collision, were observed in the convergences, while the coalescence did not occur. Furthermore, it was found that the present constructal design with varied channel size was beneficial to the droplet breakup. The size of droplet decreased and the number of them increased along the honeycomb network, leading to the increased the contact area between the two phases. © 2020 Elsevier B.V.