A phase‐field based model for coupling two‐phase flow with the motion of immersed rigid bodies

The interaction of immersed rigid bodies with two-phase flow is of high interest in many applications. A model for the coupling of a Hohenberg–Halperin type model for two-phase flow and a fictitious domain method for consideration of rigid bodies is introduced leading to a full multiphase-field method to address the overall problem. A normalized phase variable is used alongside a method for application of wetting boundary conditions over a diffuse fluid-solid interface. This enables the representation of capillary effects and different wetting behavior based on Young's law. A number of simulations is conducted in order to validate the model and highlight its ability to handle a variety of setups for two-phase particulate flow. This includes dynamic wetting situations, the motion of multiple particles within the two-phase flow and the interaction with arbitrarily shaped solid structures inside the domain.