[Noor Ilyana]

Hi,

I need help to set up symmetry boundary condition in OpenFoam. I set up a case to study fluid flow through a rectangular opening. My boundaries includes INLET, OUTLET, WALL and BOX1 (left and right planes) and BOX2 (front and back planes). I constructed the mesh using ICEM CFD 18.2 and used fluent.msh file in the OpenFoam. I would like to assign BOX1 and BOX2 to be a symmetical boundary so that I could eliminate the wall effect on the fluid flow. The results shows that the fluid velocity field is smaller near the wall than in the middle which mean the boundary set up maybe wrong. Could anyone help me to set up the symmetry boundary condition correctly? Below are the command used in the OpenFoam boundary files.

*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.7.x |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object Ksl;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [1 -3 -1 0 0 0 0];

internalField uniform 0;

boundaryField
{
OUTLET
{
type zeroGradient;
}
WALL
{
type zeroGradient;
}
INLET
{
type zeroGradient;
}
BOX1
{
type symmetry;
}
BOX2
{
type symmetry;
}
}


// ************************************************** *********************** //

Attached are the results from the simulation for your reference.