The Rotating Machinery, Laminar Flow, Level Set multiphysics interface () found under the Multiphase Flow > Rotating Machinery, Two-Phase Flow, Level Set branch (), is a multiphysics interface designed to track the interface between two immiscible fluids in equipment containing one or more rotating parts. The flow is assumed to be laminar, that is, to be of low to moderate Reynolds number.

When adding the Rotating Machinery, Laminar Two-Phase Flow, Level Set multiphysics interface, a Laminar Flow and a Level Set interface are added to the Model Builder. A Moving Mesh interface with a Rotating Domain node is added automatically in the Model Builder under the Definitions node. In addition, a multiphysics coupling feature, The Two-Phase Flow, Level Set Coupling Feature, is added automatically under the Multiphysics node. The Wetted Wall Coupling Feature is also added, but with empty selection. Other Wetted Wall multiphysics coupling features and The Interior Wetted Wall Coupling Feature can be added when needed to model walls.

By default the fluid flow discretization is set to P1+P1, and the level set discretization is set to Linear. This combination provides exact conservation of the integral of the level set variable when using the nonconservative form of the level set equation.