Use this node to set up transport across boundaries where both convective inflow and outflow occur. On the parts where fluid flows into the domain, an exterior species concentration is prescribed. On the remaining parts, where fluid flows out of the domain, a condition equivalent to the Outflow node is instead prescribed.

The Open Boundary condition is only available for exterior boundaries adjacent to a Phase Transport Properties domain and thus it is not applicable for exterior boundaries adjacent to a porous domain.

Specify a value or expression for the Exterior volume fraction for each phase not computed from the volume constraint.