This section is available when a temperature-dependent density defined in a material is used. On the material frame, the density is evaluated in relation to a reference temperature in order to ensure conservation of the mass in the presence of temperature variations. By default the Common model input is used. This corresponds to the variable
minput.Tempref, which is set to 293.15 K by default. To edit it, click the
Go to Source button (
), and in the
Default Model Inputs node under
Global Definitions, set a value for the
Volume reference temperature in the
Expression for remaining selection section.
The other options are User defined and all temperature variables from the physics interfaces included in the model.
This section is available when material properties are temperature-dependent. By default, the temperature of the parent interface is used and the section is not editable. To edit the Temperature field, click
Make All Model Inputs Editable (
). The available options are
User defined (default),
Common model input (the
minput.T variable, set to 293.15 K by default) and all temperature variables from the physics interfaces included in the model. To edit the
minput.T variable, click the
Go to Source button (
), and in the
Default Model Inputs node under
Global Definitions, set a value for the
Temperature in the
Expression for remaining selection section.
This section is available only when the Local Thermal Nonequilibrium multiphysics coupling is included in the component to model porous media. It makes it possible to define different material properties for the porous matrix and the fluid.
Select any material from the list to define the Solid material. The default uses the
Domain material. See
Material Density in Features Defined in the Material Frame for the setting of a temperature-dependent density.
The thermal conductivity k describes the relationship between the heat flux vector
q and the temperature gradient
∇T in
q = −k∇T, which is Fourier’s law of heat conduction. Enter this quantity as power per length and temperature.
The default Thermal conductivity k is taken
From material. For
User defined select
Isotropic,
Diagonal,
Symmetric, or
Full based on the characteristics of the thermal conductivity, and enter another value or expression. For
Isotropic enter a scalar which will be used to define a diagonal tensor. For the other options, enter values or expressions into the editable fields of the tensor.
The components of the thermal conductivity k when given on tensor form (
kxx,
kyy, and so on, representing an anisotropic thermal conductivity) are available as
ht.kxx,
ht.kyy, and so on (using the default name
ht). The single scalar mean effective thermal conductivity
ht.kmean is the mean value of the diagonal elements
kxx,
kyy, and
kzz.
The heat capacity at constant pressure describes the amount of heat energy required to produce a unit temperature change in a unit mass.
In addition, the thermal diffusivity α, defined as
k ⁄ (
ρ Cp) (SI unit: m
2/s), is also a predefined quantity. The thermal diffusivity can be interpreted as a measure of thermal inertia (heat propagates slowly where the thermal diffusivity is low, for example). The components of the thermal diffusivity
α, when given on tensor form (
αxx,
αyy, and so on, representing an anisotropic thermal diffusivity) are available as
ht.alphaTdxx,
ht.alphaTdyy, and so on (using the default physics name
ht). The single scalar mean thermal diffusivity
ht.alphaTdMean is the mean value of the diagonal elements
αxx,
αyy, and
αzz. The denominator
ρ Cp is the effective volumetric heat capacity which is also available as a predefined quantity,
ht.C_eff.