Numerical simulation of mixing-induced dynamic interfacial tension inside droplet by lattice Boltzmann method

Miscible reagents inside moving droplets with uneven interfacial tension result in a radically different mixing mechanism due to the dynamic interfacial tension. It is still challenging to measure mixing-induced dynamic interfacial tension via experimental technology. Herein, a ternary color-gradient lattice Boltzmann model was adopted to investigate the effect of dynamic interfacial tension on the mixing inside moving droplets under different initial component distributions. The present model has the advan-tage of independently setting diffusion coefficient and interfacial tension with high accuracy. The simu-lation results showed that dynamic interfacial tension influences the mixing by redistributing components, which primarily counts on the relative position of components and the inner swirls. Especially for the typical component distribution, the mixing performance inside droplets with dynamic interfacial tension would be significantly improved compared to various channels. Moreover, it was also found that the wall constraint reduces the positive effect on mixing caused by dynamic interfacial tension.(c) 2023 Elsevier Ltd. All rights reserved.