Numerical study of droplet behavior passing through a constricted square channel

Snap-off is a crucial mechanism for drop breakup in multiphase flow within porous media. However, the systematic investigation of snap-off dynamics constricted capillaries with varying pore and throat heights remains limited. In this study, we conducted three-dimensional simulations behavior square capillary non-uniform depth, employing color-gradient lattice Boltzmann model. Our analysis encompassed comprehensive range parameters, including geometrical factors physical properties, such as number, initial size, viscosity ratio, constriction length, presence soluble surfactants. Depending on these exhibited either or deformation it traversed constriction. Upon occurrence, quantified two significant aspects: time t̂b, which represents interval between front passing center event, volume first daughter V̂d generated by mechanism. Consistently, observed power-law relationship t̂b number Ca. variation Ca more complex behavior, influenced additional factors, ratio surfactants, break linear increase Notably, inclusion surfactants able to homogenize drop. Through our numerical provide valuable insight into process capillaries. This research contributes understanding facilitates optimization processes involving