Abstract
A VOF-IBM approach for the direct numerical simulation of three-phase flows is proposed. It resolves the flow around each bubble, droplets and solid particles in gas-liquid-solid or liquid-liquid-solid system. Implementation of moving rigid surface in a fluid is based on an immersed boundary method (IBM) of body-force type, which has been developed by the authors. In this method, the inter-phase momentum exchange is calculated by the distributed interaction-force field shared by both Eulerian and Lagrangian references. Interface between the two species of fluids is captured by volume of fluid (VOF) method. In this approach, a volume-averaged velocity field of the exiting solid and fluids phases is governed by the equation of continuity and the Navier-Stokes equation with the above interaction force and surface tension. Our method allows to solve interaction between each phase without using empirical correlations. The applicability of the present method is demonstrated through bubble-particle interaction problems in 2-D flow fields under the effect of gravity.
