The Laminar Flow version of the Rotating Machinery, Mixture Model (mm) interface () is used to model low to moderate Reynolds number flow of a multiphase mixture in equipment containing one or more rotating parts. The mixture consists of a liquid with dispersed particles, bubbles, liquid droplets, or solid particles, which are assumed to always travel with terminal velocity.

There are two study types available for this physics interface. For the Time Dependent study type the rotation is achieved by moving mesh functionality, also known as sliding mesh. For the Frozen Rotor study type the rotating parts are kept frozen in position, and the rotation is accounted for by the inclusion of centrifugal and Coriolis forces.

When this physics interface is added, the following default nodes are also added in the Model Builder under Mixture Model, Laminar Flow — Mixture Properties, Wall, and Initial Values. A Moving Mesh interface with a Rotating Domain node is added automatically in the Model Builder under the Definitions node. Then, from the Physics toolbar, add other nodes that implement, for example, boundary conditions. You can also right-click Mixture Model, Laminar Flow to select physics features from the context menu.

The Label is the default physics interface name.

The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.

The default Name (for the first physics interface in the model) is mm.

To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog. Normally these settings do not need to be changed.

Select the Use pseudo time stepping for stationary equation form checkbox to add pseudo time derivatives to the equation when the Frozen Rotor equation form is used. (Frozen rotor is a pseudo stationary formulation.) When selected, also choose a CFL number expression — Automatic (the default) or Manual. Automatic sets the local CFL number (from the Courant–Friedrichs–Lewy condition) to the built-in variable CFLCMP which in turn triggers a PID regulator for the CFL number. For Manual enter a Local CFL number CFLloc (dimensionless).