atmEpsilonWallFunction
boundary condition provides a wall constraint on the turbulent kinetic energy dissipation rate, i.e. epsilon
, and the turbulent kinetic energy production contribution, i.e. G
, for atmospheric boundary layer modelling.atmEpsilonWallFunction
condition inherits the traits of the epsilonWallFunction
boundary condition.Required fields:
epsilon | Turbulent kinetic energy dissipation rate [m2/s3]
The boundary condition expression is (([63], Eq. 8), ([59], Eq. 7)):
\[ \epsilon = \frac{w C_\mu^{3/4} k^{3/2}}{\kappa (y + z_0)} \]
when \(y^+ < y^+_{lam}\) and lowReCorrection=true
:
\[ \epsilon = \frac{2.0 w k \nu }{(y + z_0)^2} \]
where
\( \epsilon \) | = | Turbulent kinetic energy dissipation rate [m2/s3] |
\( w \) | = | Cell-corner weights [-] |
\( C_\mu \) | = | Empirical model constant [-] |
\( k \) | = | Turbulent kinetic energy [m2/s2] |
\( \kappa \) | = | von Kármán constant [-] |
\( y \) | = | Ground-normal height [m] |
\( z_0 \) | = | Surface roughness length [m] |
\( \nu \) | = | Kinematic viscosity of fluid [m2/s2] |
Example of the boundary condition specification:
<patchName> { // Mandatory entries (unmodifiable) type atmEpsilonWallFunction; // Mandatory entries (runtime modifiable) z0 uniform 0.001; // Optional (inherited) entries Cmu 0.09; kappa 0.41; lowReCorrection false; }
where the entries mean:
Property | Description | Type | Required | Default |
---|---|---|---|---|
type | Type name: atmEpsilonWallFunction | word | yes | - |
z0 | Surface roughness length [m] | PatchFunction1<scalar> | yes | - |
Cmu | Empirical model constant | scalar | no | 0.09 |
kappa | von Kármán constant | scalar | no | 0.41 |
lowReCorrection | Flag: apply low-Re correction | bool | no | false |
The inherited entries are elaborated in:
Tutorial:
Source code
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