nutkRoughWallFunction

Description

The nutkRoughWallFunction is boundary condition that provides a wall-function for the turbulent viscosity (i.e. nut) when using wall functions for rough walls, based on the turbulent kinetic energy (i.e. k). The condition manipulates the wall roughness parameter (i.e. E) to account for roughness effects.

Parameter ranges:

• Roughness height (i.e. Ks)= sand-grain roughness (0 for smooth walls)
• Roughness constant (i.e. Cs) = 0.5-1.0.

Usage

The condition requires entries in both the boundary and field files.

Boundary file

<patchName>
{
    type            wall;
    ...
}

Field file

<patchName>
{
    // Mandatory entries
    type            nutkRoughWallFunction;
    Ks              <scalarField>;
    Cs              <scalarField>;

    // Inherited entries
    ...
}

where:

Property	Description	Type	Required	Default
type	Type name: nutkRoughWallFunction	word	yes	-
Ks	Sand-grain roughness height	scalarField	yes	-
Cs	Roughness constant	scalarField	yes	-

The inherited entries are elaborated in:

• nutkWallFunctionFvPatchScalarField.H

Further information

Tutorial:

• damBreakWithObstacle

Source code:

• nutkRoughWallFunction

API:

• Foam::nutkRoughWallFunctionFvPatchScalarField

History: Introduced in version 2.4.0