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
mt.
In 2D and 1D axisymmetric components, set the Thickness dz, which is the thickness of the domain in the out-of-plane direction. The default value is 1 m.
In 1D components, set the Cross sectional area Ac and the
Cross sectional perimeter Pc of the domain. Default values are 1 m
2 and
, respectively.
Set the Reference vapor concentration which is used when the moisture transport interface is coupled to a fluid flow interface with the
Incompressible flow option selected in the
Compressibility list. In this case, the fluid density is evaluated at the
Reference pressure level (defined in the
Physical Model section of the fluid flow interface), at the reference temperature defined in the moisture transport interface (293.15 K), and at the
Reference vapor concentration specified in this section.
Note that in hygroscopic porous media domains, the Concentrated species formulation is always used, and this setting is not used. In building materials domains, this setting has no effect either.
The Streamline diffusion check box is selected by default and should remain selected for optimal performance for applications that include a convective or translational term.
Crosswind diffusion provides extra diffusion in regions with sharp gradients. The added diffusion is orthogonal to the streamlines, so streamline diffusion and crosswind diffusion can be used simultaneously. The
Crosswind diffusion check box is also selected by default.
The Isotropic diffusion check box is not selected by default. To add isotropic diffusion, select the
Isotropic diffusion check box. The field for the tuning parameter
δid then becomes available. The default value is 0.25; increase or decrease the value of
δid to increase or decrease the amount of isotropic diffusion.
To display this section, click the Show More Options button (
) and select
Advanced Physics Options. These settings only apply to the domains in which either a
Moist Air feature or an
Hygroscopic Porous Medium feature is active. Select a
Convective term —
Non-conservative form (the default) or
Conservative form. The latter should be used for compressible flow.
To display all settings available in this section, click the Show More Options button (
) and select
Advanced Physics Options in the
Show More Options dialog box. The shape functions used for the relative humidity are by default
Quadratic Lagrange in building materials and porous media, and
Linear in moist air.