The Laminar Two-Phase Flow, Moving Mesh interface (), found under the Multiphase Flow>Two-Phase Flow, Moving Mesh branch (), is a multiphysics interface designed to model laminar two–phase flow of immiscible fluids separated by a moving interface. The velocity field, pressure, and mesh deformation are solved for, and the location of the interface is tracked by the deformed mesh.

When adding the Laminar Two-Phase Flow, Moving Mesh multiphysics interface, a Laminar Flow interface is added to the component, and a Moving Mesh interface with a Deforming Domain feature is added under the Definitions node. The Laminar Flow interface adds the Navier–Stokes equations and provides a way of defining the properties of the fluids. For each of the fluids the density and viscosity must be specified (these are typically taken from the corresponding materials, but can be user defined).

Simulations using the Laminar Two-Phase Flow, Moving Mesh interface are always time-dependent since the position of an interface is almost always dependent of its history. There are additional boundary conditions to describe how the fluid-fluid interface moves from the Laminar Flow context menu under the option Fluid Interface Features: