Hi all,

I have a quick question concerning permeability tensor for 2D surfaces in 3D model using local coorinates.

From what I understood, it is used to give values of the permeabiltiy along the 2D surface (in my case a fault).

I checked the function CFiniteElementStd::CalcCoeffLaplace() in fem_ele_std.cpp but I still haven’t figured everything out.

So for the given material, I can write for example:

#MEDIUM_PROPERTIES

$GEOMETRY_DIMENSION

2

.

.

.

$PERMEABILITY_TENSOR

ORTHOTROPIC xx yy

Then to which direction exactly will the values xx and yy be assigned?

Is it also possible to specify the permeability **across** the surface element?

Thank you in advance.

Best,

Antoine

Hi Antoine,

So for the given material, I can write for example:

#MEDIUM_PROPERTIES

$GEOMETRY_DIMENSION

2

.

$PERMEABILITY_TENSOR

ORTHOTROPIC xx yy

Then to which direction exactly will the values xx and yy be assigned?

I'm not quite sure but guess that depends on each element. Current OGS rotates each surface element to XY plane, convert the given local permeability tensor to global one using the rotation matrix. For details of computing a rotation matrix, you can check CElem::FillTransformMatrix() in MSH/msh_elem.cpp

Is it also possible to specify the permeability *across* the surface

element?

No, you need a volume element for it.

## ···

--

Dr.-Ing. Norihiro Watanabe

Department of Environmental Informatics

Helmholtz-Zentrum für Umweltforschung GmbH - UFZ

Helmholtz Centre for Environmental Research GmbH - UFZ

Permoserstraße 15 / 04318 Leipzig / Germany

Telefon +49 341 235 1806

norihiro.watanabe@ufz.de / www.ufz.de

Sitz der Gesellschaft: Leipzig

Registergericht: Amtsgericht Leipzig, Handelsregister Nr. B 4703

Vorsitzender des Aufsichtsrats: MinDirig Wilfried Kraus

Wissenschaftlicher Geschäftsführer: Prof. Dr. Georg Teutsch

Administrativer Geschäftsführer: N.N.

Thanks for your answer Nori.

I will have a look at that.

Antoine