Simulation of drop motion and breakup in narrow pores

Abstract

We used a boundary-integral algorithm to simulate drops passing through narrow pores, with three possible outcomes: passage without breaking, breakup due to contact with a bifurcation or corner, and breakup due to elongation. Smaller drops with low capillary numbers and high viscosities are more likely to go through the pores without breaking, larger drops are more prone to hit a pore bifurcation and break, and drops with large capillary numbers and same or lower viscosities than the bulk fluid are more likely to experience elongation and breakup. Pore geometry also has a strong effect, with relatively little breakup when there is no bifurcation. Finally, the post-pore size distribution of droplet sizes is relatively broad when the pre-pore size of the parent drops is large, but the post-pore size distribution is narrow for smaller parent drops (due to little or no breakup). These results may help guide emulsification processes.