The Boundary Stress node adds a boundary condition that represents a general class of conditions also known as traction boundary conditions.
The Boundary condition options for the boundary stress are
General stress,
Normal stress, and
Normal stress, normal flow.
When General stress is selected, the components for the
Stress F should be specified. The total stress on the boundary is set equal to the given stress
F:
Normal Stress is described for the Open Boundary node.
For Normal stress, normal flow, the magnitude of the
Normal stress f0 should be specified. The tangential velocity is set to zero on the boundary:
If Normal Stress, Normal Flow is selected as the
Boundary condition, then to
Apply reaction terms on all dependent variables, the
All physics (symmetric) option should be selected. Alternatively, the
Individual dependent variables could be selected to restrict the reaction terms as needed.