A pseudo friction law with no bottom friction. More...
#include <dumux/material/fluidmatrixinteractions/frictionlaws/nofriction.hh>
A pseudo friction law with no bottom friction.
Public Member Functions | |
FrictionLawNoFriction ()=default | |
Constructor. More... | |
Dune::FieldVector< Scalar, 2 > | bottomShearStress (const VolumeVariables &volVars) const final |
Compute the bottom shear stress. More... | |
virtual Dune::FieldVector< Scalar, 2 > | shearStress (const VolumeVariables &volVars) const |
Scalar | limitRoughH (const Scalar roughnessHeight, const Scalar waterDepth) const |
Limit the friction for small water depth. More... | |
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default |
Constructor.
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inlinefinalvirtual |
Compute the bottom shear stress.
volVars | Volume variables |
Compute the bottom shear stress due to bottom friction. The bottom shear stress is a projection of the shear stress tensor onto the river bed. It can therefore be represented by a (tangent) vector with two entries. For this law without bottom friction, the bottom shear stress is zero.
Implements Dumux::FrictionLaw< VolumeVariables >.
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inlineinherited |
Limit the friction for small water depth.
We define a water depth minUpperH. If the water depth is smaller, we start to limit the friction. So the friction term get's not extreme large for small water depths.
----------------------— minUpperH --------—
---------------------—roughnessHeight ------------— /\ /\ roughness /grain\ ----------------------------—bottom ---------------— /////////////////////////////////////////////////
For the limiting the LET model is used, which is usually applied in the porous media flow to limit the permeability due to the saturation. It employs the three empirical paramaters L, E and T, which describe the limiting curve (mobility).
auto mobility = (mobility_max * pow(sw,L))/(pow(sw,L) + E * pow(1.0-sw,T));
For the limitation of the roughness height L = 0.0, T = 2.0 and E = 1.0 are choosen. Therefore the calculation of the mobility is simplified significantly.
roughnessHeight | roughness height of the representative structure (e.g. largest grain size). |
waterDepth | water depth. |
< maximal mobility
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inlinevirtualinherited |