The Barrier boundary condition models interior permeable walls, membranes, geotextiles, or perforated plates as thin permeable barriers. The Barrier boundary condition can only be applied on interior boundaries.

Enter a value or expression for the Thickness db (SI unit: m, the default is 0.1 m) and for the Permeability κb (SI unit: m2). The default Permeability κb uses the value From material. For User defined select Isotropic to define a scalar value or Diagonal, Symmetric, or Full to define a tensor value and enter another value or expression in the field or matrix.

Physics tab with Darcy’s Law or Richards’ Equation selected: