Use the Pressure node to specify the pressure on a boundary. In many cases the distribution of pressure is known, giving a Dirichlet condition
p =
p0 where
p0 is a known pressure given as a number, a distribution, or an expression involving time,
t, for example.
If this node is selected from the Pairs menu, choose the pair to apply this condition to. A pair must be created first. See
Identity, Contact, and Sector Symmetry Pairs in the
COMSOL Multiphysics Reference Manual for more details.
Enter a value or expression for the Pressure p0 (SI unit: Pa). Enter a relative pressure value in
p0 (SI unit: Pa).
For the Subsurface Flow Module, the Pressure node provides the pressure
P0 as a condition on edges in 3D models. Then select the edges under
Edge Selection.
As an attribute to the Fracture boundary condition or as boundary condition to
The Fracture Flow Interface (which are available in the Subsurface Flow Module and the Porous Media Flow Module), the pressure can also be specified on edges (in 3D) or points (in 2D) surrounding the fracture domain. In other cases, pressure constraints on edges or points are not implemented.
) and select Advanced Physics Options in the Show More Options dialog.