Use the Wall node to model the most common conditions at solid surfaces. This is the default boundary condition. This condition contains both a mechanical and a thermal selection. The default is a no-slip and isothermal condition applicable in most cases. More advanced conditions at boundaries can be set up by combining any of the
Mechanical and
Thermal conditions available.
The Wall condition is also the default condition added when the physics interface is set up. Note that the selections in this default condition can be changed (they are not locked to all boundaries). When used together with a perfectly matched layer (PML) it is recommended to use the no-slip option at the outer boundary of the layer. Specifically, using the slip condition in combination with a rational scaling in the PML will lead to a singularity and an error.
Select a Mechanical condition —
No slip (the default) or
Slip. See the
No Slip and
Slip conditions for further details.
Select a Thermal condition —
Isothermal (the default) or
Adiabatic. See the
Isothermal and
Adiabatic conditions for further details.
To display this section, click the Show More Options button (
) and select
Advanced Physics Options in the
Show More Options dialog box. If
Slip is selected for the
Mechanical condition and
Use weak constraints is enabled, then the default discontinuous Galerkin (penalty like) formulation is switched to a Lagrange multiplier formulation instead. See the
Slip condition for details. For the
No-slip and
Isothermal selections a weak formulation is used instead of a pointwise constraint.
) and select