New coarsening mechanisms for spinodal decomposition having droplet pattern in binary fluid mixture: Collision-induced collisions

The elementary process of droplet coarsening has been studied for phase-separating binary liquid mixtures. For a slightly asymmetric quench, we have found two new types of coarsening behavior: (i) a multiple collision caused by the coupling effect between the shape relaxation after binary collision and the geometrical configuration of neighboring droplets and (ii) a collision-induced collision likely caused by collision-diffusion coupling. For a nearly symmetric mixture the droplet density is so high that we probably need to consider new mechanisms of droplet coarsening unique to fluid systems, which originate from the coupling between concentration and velocity fields.