); Two-Phase Flow, Phase Field (
); and Two Phase Flow, Moving Mesh (
) interfaces are used to model two fluids separated by a fluid-fluid interface. The moving interface is tracked in detail using the level set method, the phase field method, or by a moving mesh, respectively. The level set and phase field methods use a fixed mesh and solve additional equations to track the interface location. The moving mesh method solves Navier–Stokes equations on a moving mesh with boundary conditions to represent the interface. In this case, equations must be solved for the mesh deformation. Since a surface in the geometry is used to represent the interface between the two fluids in the Moving Mesh interface, the interface itself cannot break up into multiple disconnected surfaces. This means that the Moving Mesh interface cannot be applied to problems such as droplet formation in inkjet devices (in these applications the level set or phase field interfaces are appropriate). These physics interfaces support incompressible flows, where one or both fluids can be non-Newtonian.
) is used to track the interface between two fluids in porous medium.
) models laminar flow of three incompressible phases that can be Newtonian or non-Newtonian. The moving fluid-fluid interfaces between the three phases are tracked in detail using the phase-field method.