Periodic Condition
Use this node to prescribe periodic conditions on moisture. Depending on the domain condition active in the adjacent domain, the constraint is applied either on relative humidity, vapor concentration or vapor mass fraction on boundary pairs. For periodic temperature and pressure conditions, all these constraints are equivalent.
Boundary Selection
The software automatically identifies the boundaries as either source boundaries or destination boundaries. The selection for the destination can be changed by right-clicking the Periodic Condition node to add a Destination Selection subnode.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.
The Constraint settings can be set to Nitsche constraints (default), Pointwise constraints or Weak constraints. The Nitsche constraints option ensures continuity of the diffusive flux. This option may work better than the Pointwise constraints or Weak constraints when the meshes of the source and destination boundaries do not coincide. Alternatively, select the Pointwise constraints option. Select Weak constraints to replace the standard constraints with a weak implementation.
Orientation of Source
To display this section, click the Show More Options button () and select Advanced Physics Options.
See Orientation of Source and Destination in the COMSOL Multiphysics Reference Manual.
Mapping between Source and Destination
To display this section, click the Show More Options button () and select Advanced Physics Options.
See Mapping Between Source and Destination in the COMSOL Multiphysics Reference Manual.
Location in User Interface
Context Menus
Ribbon
Physics Tab with interface as Moisture Transport in Air, Moisture Transport in Building Materials, or Moisture Transport in Porous Media selected: