Add a Multiphase Material node (

) under a
Materials node in a model component to define a material composed of two or more immiscible phases. Instead of resolving the exact position in space of each phase, they are approximated by their volume fraction, and the effective properties of the material are obtained from a set of mixing rules.
The Volume fraction definition can either be
Locally defined or controlled from a physics interface providing volume fractions, such as the
Level Set,
Phase Field,
Ternary Phase Field, and
Phase Transport interfaces. The default is
Locally defined. When the volume fractions are defined locally, they can be specified as user inputs in each
Phase (Subnode) subnode or in the phases table described below. The Multiphase Material feature will automatically constrain each volume fraction to be between 0 and 1.
Use the Constrained phase setting to control which phase that does not have an explicit definition of its volume fraction but instead gets the remaining volume fraction as 1 minus the sum of fractions from the other phases. The default is
First phase.
The Phases table displays a summary of all of the phases in the material, the source of their material properties, and their volume fraction expression. See
Phase (Subnode) for more information.
When the Mixing rule for a material property is set to
From homogenized properties, enter values or expressions for the properties in the
Homogenized Properties section.
From the Material list, choose the material to represent the homogenized material properties:
Locally defined (the default), or select any other material that you have added. Click the
Go to Material button (

) to move to the selected material’s node. Click the
Add Material from Library button (

) to add a material from the
Add Material from Library window. You can also click the downward arrow next to the button and choose
Blank Material to add a new blank material. In both cases, the added material becomes selected in the
Material list.
Material properties that use From homogenized properties instead of a specific mixing rule are shown in the
Homogenized Properties table. The properties are to be thought of as homogenized in some matter other than through the available mixing rules. When the
Material in the
Homogenized Material section is
Locally defined, enter values or expressions for the properties in the
Value column. You can also click the
Edit button (

) below the table to enter the property values.