Any material can consist of one or more materials. If a material contains only a single pure species, then it is known as a pure substance. If it contains more than one species, then it is known as a mixture. The materials are assumed to be mixed at the molecular level in the mixture.
The type of material is set using the following options:
The
Pure Substanceoption should be used to create a fluid whose properties, such as viscosity, density, or molar mass, are known. All existing and newly created pure substances appear in the materials list and you can then create mixtures from them. For details, see Material Details View: Pure Substance.The
Fixed Composition Mixtureoption should be used to create a mixture with fixed mass fractions of each material. The mass fraction of each material is specified and is not allowed to change during the course of the simulation in space or time. For details, see Material Details View: Fixed Composition Mixture.The
Variable Composition Mixtureoption should be used to create a mixture whose mass fractions are allowed to change during the course of a simulation in space and time. The mass fraction of each material is not specified when defining the fluid. You can use a fixed composition mixture as a material in a variable composition mixture.For details, see Material Details View: Variable Composition Mixture.
The
Homogeneous Binary Mixtureoption applies to equilibrium phase change calculations. For details, see Material Details View: Homogeneous Binary Mixture.The
Reacting Mixtureoption is used for a chemical reaction, such as combustion.For details, see Material Details View: Reacting Mixture.
The
Hydrocarbon Fueloption. For details, see Material Details View: Hydrocarbon Fuel.
The Material Group filter is used to group materials by type, as well as restrict what materials can be mixed when the physical models include reactions or phase change. A material can be a member of more than one material group if it has a consistent set of properties. Material Group will always be set to at least one of the following:
Any user-defined materials, not assigned to one of the other groups, are shown in or can be added to this group. For example, materials loaded from a previous CFX-Pre simulation are shown in this group.
This group contains Ideal Gas and constant property air. Constant properties are for dry air at both 0 [C], 1 [atm] (STP) and 25 [C], 1 [atm].
Contains solid substances that can be used for solid domains when performing conjugate heat transfer modeling.
These groups contain gas and liquid substances with constant properties.
The gas properties are calculated at STP (0 [C] and 1 [atm]). Gas materials in this group can be combined with NASA SP-273 materials for use in combustion modeling simulations.
No materials appear in this group by default, they must be loaded from a pre-supplied materials file. All materials in this group use the built-in Redlich-Kwong equation of state and are suitable for performing equilibrium, homogeneous, phase change modeling.
For any given pure substance, there are three different materials.
There is a material with a RK tag, used for dry
vapor calculations, and three materials with RKv, RKl and RKlv suffixes,
which are used for equilibrium phase change (wet vapor) calculations.
No materials appear in this group by default, they must also be loaded from a pre-supplied materials file. All materials in this group use the Redlich-Kwong equation of state with properties specified in an RGP file. These materials are suitable for performing equilibrium, homogeneous, phase change modeling.
Like the built-in Redlich Kwong group, for any given pure substance
there are three different materials. There is a material with a RK tag, used for dry vapor calculations, and three materials
with RKv, RKl and RKlv suffixes, which are used for equilibrium phase change
(wet vapor) calculations.
No materials appear in this group by default, they must also be loaded from a pre-supplied materials file. All materials in this group use the Redlich-Kwong equation of state with properties specified in an RGP file. These materials are suitable for performing equilibrium, homogeneous, phase change modeling.
Like the built-in Redlich Kwong group, for any given pure substance
there are three different materials. There is a material with a RK tag, used for dry vapor calculations, and three materials
with RKv, RKl and RKlv suffixes, which are used for equilibrium phase change
(wet vapor) calculations.
No materials appear in this group by default, they must also be loaded from a pre-supplied materials file. All materials in this group use the Redlich-Kwong equation of state with properties specified in an RGP file. These materials are suitable for performing equilibrium, homogeneous, phase change modeling.
Like the built-in Redlich Kwong group, for any given pure substance
there are three different materials. There is a material with a RK tag, used for dry vapor calculations, and three materials
with RKv, RKl and RKlv suffixes, which are used for equilibrium phase change
(wet vapor) calculations.
No materials appear in this group by default, they must also be loaded from a pre-supplied materials file. Materials in this group use the IAPWS equation of state. Again, the materials are suitable for either dry or wet steam calculations.
Contains materials that can be used for gas phase combustion. All materials in this group use the Ideal Gas equation of state. The specific heat capacity, enthalpy and entropy for each of the materials are specified using the NASA SP-273 format. For details, see NASA Format in the CFX-Solver Modeling Guide.
This group contains materials that can be used for Eulerian or Lagrangian interphase mass transfer. This group currently contains a number of materials that have liquid or gas reference states, which are consistent for performing phase change calculations. The gas phases use the ideal gas equation of state and temperature-dependent specific heat capacity. The associated liquid phases use constant properties.
Contains a list of solids that can be used in Particle Tracking calculations.
This group contains solid substances that can be used when performing soot calculations.
This parameter can be toggled on to view a detailed description
of the substance. Click Edit the Material Description 
to edit the description (to a maximum of 120
alphanumeric characters).
This parameter sets the state of a substance to solid, liquid or gas. There are certain limitations imposed by selecting a particular state. For example, a solid must always have at least density, specific heat capacity and thermal conductivity specified.
For material properties that are set using expressions containing X, Y, or Z, you may want to supply a custom coordinate frame as the basis for evaluation of such properties. For details, see Coordinate Frame, Coordinate Frames, and Coordinate Frames in the CFX-Solver Modeling Guide.