Periodic Condition
Use this node to add a periodic condition to at least two boundaries (source and destination boundaries). It applies a pressure condition as follows:
Flow Condition
Specify either a Pressure difference Δp or a Mass flow . If the mass flow option is selected, the pressure difference is computed such that
Boundary Selection and Orientation
The software usually automatically identifies the boundaries as either source or destination boundaries, as indicated in the selection list. This works fine for cases like opposing parallel boundaries. In other cases, right-click Periodic Flow Condition and select Manual Destination Selection to control the destination.
More details on how to handle curved boundaries and mapping between source and destination are located in the Periodic Boundary Conditions section in the Comsol Multiphysics Reference Manual.