Porous medium models

This class allows the optional activation of a double porosity model for fluid flow in porous medium.

The porous medium model can be specified using the keyword :

porousMediumModel dualPorosity;

in the constant/transportProperties file.

If not defined, the solver considers the of the simple porosity model (simplePorosity).

Warning

Dual porosity is available only for unsaturated Richards solver, i.e. groundwaterFoam solver and groundwaterTransportFoam solver.

Simple porosity

For the simple porosity model, you may specifiy uniform porosity or permeability in constant/transportProperties:

eps [0 0 0 0 0 0 0] 0.305;
K [0 2 0 0 0 0 0] 1.25e-12;

Note that you may specify non-uniform permeability or porosity field in constant/K or constant/eps.

Dual porosity

In the case of dual porosity model, you may specify the properties of the second porous region in a dedicated dictionary dualPorosityCoeffs in the constant/transportProperties :

KFracture [0 2 0 0 0 0 0] 1.1798e-12;

dualPorosityCoeffs
{
  a [0 1 0 0 0 0 0] 0.01;
  beta [0 0 0 0 0 0 0] 3;
  gammaW [0 0 0 0 0 0 0] 0.4;
  Kmatrix [0 2 0 0 0 0 0] 1.1798e-14;
  Kexchange [0 2 0 0 0 0 0] 1.17982e-16;
}

where :

a/beta/gammaW :: the coefficient related to the dual porosity model
Kmatrix :: the permeability of the matrix medium
Kexchange :: the permeability exchange between the two medium

Note that the dualPorosity model use KFracture field instead of the classical permeability K to avoid confusion

As for simple porosity model, the permeabilities can be specified as non-uniform in constant/KFracture, constant/Kmatrix and constant/Kexchange.

Parameters for relative permeabilities and capillary pressure should be specified for each medium, Fracture and Matrix, in constant/transportProperties:

VanGenuchtenCoeffs
{
  //- fracture properties
  thetaFracturemin 0;
  thetaFracturemax 0.025;
  alphaFracture 5.0;
  mFracture 0.5;
  //- matrix properties
  thetaMatrixmin 0.10;
  thetaMatrixmax 0.475;
  alphaMatrix 0.5;
  mMatrix 0.333333;
}