Numerical study of the effect of different flow conditions on the dynamics of droplet collisions between two opposite moving plates

The collision of deformable drops in the flow between two opposite moving plates (shear flow) has been studied numerically by solving the Navier-Stokes equations completely. The numerical finite difference/front tracking method is used. This method is a mixed of capturing and drop tracking methods. For a fluid bulk, a structured fixed, cubic and staggered grid would be used, but the drop is tracked using a separate grid triangle irregular and moving grid with a lower dimension than channel fluid grid. The surface tension effects are accounted for by adding appropriate source terms into the governing equations. The results showed that as the computational domain increases, the droplets are more affected by the vortex created by the intermittent reaction of the walls, and their crossing themselves motion path turns to return path. Also, by increasing the effects of inertia due to the increase in Reynolds number, the droplets make a reciprocating motion in the larger channel. As the capillary number increases, the droplets move further towards each other.