11.3.1 BOUNDARY_CONDITIONS

A boundary condition is a source which is applied over a set of faces. It should be noted that these faces need not be external to the solution domain. It is allowable to apply any of the following source types to any face, internal or on the boundary, in the solution domain.

In the .geo file the last entry on each line defining the points at the corner of a face is a face patch number. This face patch number is used in the inform to identify to which faces a boundary condition should be applied. For example, if a face has a face patch number equal to 2 then any boundary conditions applied to PATCH 2 in the inform will be applied to the face.

The following sub sections describe the standard PHYSICA sources. In the following text it will be assumed that the face is on the external boundary. Using this assumption the face is associated with only one element. If the face is internal to the domain then it will be associated with two elements and the source will be applied to both elements.