Numerical study of droplet breakup in an asymmetric T-junction microchannel with different cross-section ratios

In this study, numerical simulations are conducted to investigate droplet breakup in an asymmetric T-junction microchannel with different cross-section ratios. To this approach, a two-phase model based on the volume of fluid (VOF) method is adopted to study the three-dimensional feature of droplet motion inside T-junctions. The comparison reveals that the present results are in good agreement with previous studies. The effects of the capillary number (Ca), the non-dimensional droplet length (L*), and the non-dimensional width ratio (W*) on the breakup time and splitting ratio of daughter droplets are studied. Five distinct regimes are observed involving the non-breakup, breakup with tunnel, breakup without tunnel, asymmetric breakup, and sorting. Achieved results indicate that the time of breakup (t(breakup)*) increases about 15% when the Ca is increased from 0.0134 to 0.0268 (about 100%). It is also found that the mass center of the mother droplet in the primary channel is shifted to a larger wide branch, which facilitates the asymmetric breakup of the droplet in a T-junction microchannel.

Automated summary

In this study, numerical simulations are performed to investigate droplet breakup in an asymmetric T-junction microchannel. The results show good agreement with previous studies, and the effects of capillary number, non-dimensional droplet length, and non-dimensional width ratio on the breakup time and splitting ratio are studied. It is also found that the mass center of the mother droplet is shifted to a wider branch, facilitating the asymmetric breakup in the T-junction microchannel.