Sedimentation and flow through porous media: Simulating dynamically coupled discrete and continuum phases

Abstract

We describe a method to address efficiently problems of two-phase flow in the regime of low but non-zero particle Reynolds number and negligible Brownian motion. One of the phases is an incompressible continuous fluid and the other a discrete particulate phase which we simulate by following the motion of single particles. Interactions between the phases are taken into account using locally defined drag forces. We apply our method to the problem of flow through random media at high porosity where we find good agreement to theoretical expectations for the functional dependence of the pressure drop on the solid volume fraction. We undertake further validations on systems undergoing gravity induced sedimentation. In this context we address the effects of modeling assumptions. (c) 1995 The American Physical Society