Collision modeling between two non-Brownian particles in multiphase flow

In this paper, we develop a collision model for particle–particle and particle–wall interaction inside fluid medium based on stereomechanical impact model. One of the important parameters identified in literature that characterizes the interaction is the Stokes number (St), which is the ratio of the particles inertia and fluid viscosity. In dry air collisions, the coefficient of restitution (e) and coefficient of friction (f) are used to describe post-collision velocities on the basis of pre-collision velocities. In the case of collisions in fluid medium, we use the experimental results that provide the co-relation between the values of e and f as a function of the Stokes number. The collision models developed here are used in our direct numerical simulation of particulate flows to verify the model with some of the well-known behavior of particle interaction in fluids.