Description🔗
The atmNutkWallFunction
is a boundary condition that provides
a wall constraint on the turbulent viscosity (i.e. nut
) based on the
turbulent kinetic energy (i.e. k
) for atmospheric boundary layer modelling.
It is designed to be used in conjunction with the atmBoundaryLayerInletVelocity
boundary condition.
The governing equation of the boundary condition:
\[u = \frac{u^*}{\kappa} ln \left(\frac{z + z_0}{z_0}\right)\]where:
Property | Description |
---|---|
\(u^*\) | Friction velocity |
\(\kappa\) | von Karman constant |
\(z_0\) | Surface roughness length [m] |
\(z\) | Ground-normal coordinate |
References🔗
-
Theoretical expressions (tag:HW):
Hargreaves, D. M., & Wright, N. G. (2007). On the use of the k–ε model in commercial CFD software to model the neutral atmospheric boundary layer. J. of wind engineering and industrial aerodynamics, 95(5), 355-369. DOI:10.1016/j.jweia.2006.08.002
Usage🔗
The condition requires entries in both the boundary and field files.
Boundary file🔗
<patchName>
{
type patch;
...
}
Field file🔗
<patchName>
{
// Mandatory entries
type atmNutkWallFunction;
z0 <PatchFunction1<scalar>>;
// Optional entries
boundNut <bool>;
// Inherited entries
...
}
where:
Property | Description | Type | Required | Default |
---|---|---|---|---|
type |
Type name: atmNutkWallFunction
|
word | yes | - |
z0 |
Surface roughness length [m] | PatchFunction1<scalar> | yes | - |
boundNut |
Flag to zero-bound nut near wall | bool | no | false |
The inherited entries are elaborated in:
- nutkWallFunctionFvPatchScalarField.H
- PatchFunction1.H
Further information🔗
Tutorial:
Source code:
API:
History:
- Introduced in version v2006