Incorporation of lubrication effects into the force-coupling method for particulate two-phase flow

We investigate the performance of the force-coupling method (FCM) for particulate flow at microscales. In this work, we restrict attention to flows where we may neglect fluid inertia (Stokes flows), particle inertia and Brownian motion. The FCM performs well when distances between solid boundaries are sufficiently large, however it does not capture the local effects of viscous lubrication forces for small gap widths. To improve the results, we develop a parameterization of the lubrication forces for inclusion in the model. This is based on exact results for isolated pairs of particles and single particle–wall configurations. The correction is imposed through the addition of a lubrication barrier force on affected particles. The parameterization is tested for several cases, illustrating both the improvements possible and the limitations.