Material properties are volume conditions in the Multiphase module that refer to selected volumes.

The material properties appear in the Properties panel when you select a fluid domain in the Flow Analysis Tree under Domains.

You can specify the density for a selected volume under the Multiphase and Common module in the Properties panel.

Density of a mixture is computed from the densities of the individual components by using the following options:

Density of components is specified only under the Common module as any of the following: Constant Density, Ideal Gas Law, Isentropic Gas Law, Compressible Liquid, or User Specified by using the Expression Editor.

Viscosity of components is specified only under the Flow module as any of the following: Constant Dynamic Viscosity, Constant Kinematic Viscosity, Sutherland Law, Bingham models, Herschel-Bulkley model, User Defined Function (NonNewtonian) or User Specified using the Expression Editor.

For multiphase flow problems involving heat transfer, Enthalpy Model and Conductivity are specified.

You can specify Enthalpy Model for the mixture under both the Multiphase and Heat modules.

Enthalpy model of a mixture is determined from the enthalpies of the individual components using one of the following methods:

You can specify conductivity of a mixture under both the Multiphase and Heat modules.

Conductivity of a mixture is computed from the conductivities of the individual components using one of the following methods:

Consider the surface tension for components in a selected volume. The surface tension is only activated under the Flow module for the components that make up the mixture.

Surface tension and the associated value should only be selected for one component. Surface tension for the other components should be set to No. Whether surface tension needs to be activated depends on its magnitude relative to momentum and other forces. Weber number and Bond number serve as a measure whether to activate surface tension.