Analysis of droplet dynamics in a partially obstructed confinement in a three-dimensional channel

Abstract

This study presents droplet dynamics due to capillarity-wettability interaction through a partially obstructed channel confinement based on a mesoscopic, two-phase lattice Boltzmann model. To explore the dynamic behavior of droplet motion past an obstruction, the effects of the modified capillary number and surface wettability, including the obstruction size and architecture, are elucidated. In this work, a single spherical obstruction and different spherical agglomerate structures have been considered. The mesoscale simulations exhibit interesting two-phase flow physics and pattern formations due to droplet pinching, break up, and surface adherence owing to the underlying wettability-capillarity characteristics. This study further reveals a trade-off, between the time required for the bulk droplet fluid to pass by and/or through the obstruction and the fraction of the droplet fluid volume adhering to the surface, depending on the combination of the capillary number and surface wettability.