The Porous Medium Discontinuity boundary condition can only be applied on interior boundaries, and only when on both sides of the boundary a Phase and Porous Media Transport Properties domain condition is active. Set this condition at boundaries over which the capillary pressure function is discontinuous in the phase saturations due to the different properties of the porous matrix on both sides of the discontinuity.

This section is only available if the automatic settings are not used for the Porous Medium Discontinuity Settings, or when the Porous Medium Discontinuity Settings section is not available, which is the case if there are three or more phases present.

Specify on which side of the discontinuity the lower permeable medium is located using the settings for the of the Location of lower permeable medium.

Specify the Entry capillary pressure pec (SI unit: Pa) for all phases, except the one computed from the volume constraint. Make sure the values correspond to the settings for the capillary pressure model in the adjacent domain conditions.

To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box. You can find details about the different constraint settings in the section Constraint Reaction Terms in the COMSOL Multiphysics Reference Manual.