[kodexys]

Hello everyone, could someone please explain to me what the values in boundary patches specify? I'm trying to run simulations with roughness and I'm not sure what OpenFOAM is doing when I set something like

type     nutkRoughWallFunction
Ks        uniform 0;
Cs        uniform 0.5;
value     uniform 0;

[anishtain4]

if you look for the file in the source code you'll find this:

Description
This boundary condition provides a turbulent kinematic viscosity condition
when using wall functions for rough walls, based on turbulence kinetic
energy. The condition manipulates the E parameter to account for roughness
effects.

Parameter ranges
- roughness height = sand-grain roughness (0 for smooth walls)
- roughness constant = 0.5-1.0

\heading Patch usage

\table
Property | Description | Required | Default value
Ks | sand-grain roughness height | yes |
Cs | roughness constant | yes |
\endtable

Example of the boundary condition specification:
\verbatim
myPatch
{
type nutkRoughWallFunction;
Ks uniform 0;
Cs uniform 0.5;
}
\endverbatim

[kodexys]

Thanks Mahdi for your reply.

However, I don't see how it answers my question of what the values in boundary patches specify.