atmOmegaWallFunction

Table of Contents

Properties

  • The atmOmegaWallFunction boundary condition provides a wall constraint on the specific dissipation rate, i.e. omega, and the turbulent kinetic energy production contribution, i.e. G, for atmospheric boundary layer modelling.
  • The atmOmegaWallFunction condition inherits the traits of the omegaWallFunction boundary condition.

Required fields: 

omega    | Specific dissipation rate    [1/s]

Model equations

The boundary condition expression is ([59], [7]):

\[ \omega = \frac{w \sqrt{k} }{ C_\mu^{1/4} \kappa (y + z_0)} \]

where

\( \omega \) = Specific dissipation rate [1/s]
\( w \) = 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]

Usage

Example of the boundary condition specification: 

<patchName>
{
    // Mandatory entries (unmodifiable)
    type            atmOmegaWallFunction;

    // Mandatory entries (runtime modifiable)
    z0              uniform 0.001;

    // Optional (inherited) entries
    Cmu             0.09;
    kappa           0.41;
}

where the entries mean:

Property Description Type Required Default
type Type name: atmOmegaWallFunction 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

The inherited entries are elaborated in:

  • omegaWallFunction
  • PatchFunction1

Further information

Tutorial:

Source code

History

  • Introduced in version v2006