# Mass_Open

Syntax

  Bc Diffuse For Mass_Balance [{of} SpeciesName | {in} MaterialPhaseName | {ls} {a | b | c}] {@ | at | for | on | over} Mesh Extent Name [Touching TouchingMeshExtent | Opposing OpposingMeshExtent] = Mass_Open [Using Data Specification Data Spec Name] [Pressure = pressure]

Summary

  A weakly enforced pressure condition for open flow from a porous flow domain

Description

  This model weakly enforces a pressure condition on the boundary of a porous domain, either equal to the specified constant `PRESSURE`, or set using the `BOUNDARY_PRESSURE` model from the surface material.

  Note

  This should only be used with porous flow equations.

Parameter | Value | Default
--- | --- | ---
{of} | {of | species | subindex} | –
SpeciesName | string | –
{in} | {in | material_phase} | –
MaterialPhaseName | string | –
{ls} | {levelset_phase | ls} | –
Mesh Extent Name | string | –
TouchingMeshExtent | string | –
OpposingMeshExtent | string | –
Data Spec Name | string | –
pressure | real | 0