[ChaldExals]

Hello All,

I am new to OpenFOAM and currently trying to run a test case of turbulent channel flow with Smagorinsky LES (using pisoFoam solver). My geometry domain is 6.4m*1m*2.4m. Bulk reynolds number in terms of half channel height is 125000. I am using a simple mesh by using 50,40, and 40 cells in x,y,and z directions respectively. I am applying streamwise and spanwise cyclic boundary conditions so that i can simulate a fully developed flow. The simulation runs without any error. However, the pressure in the entire flow domain is almost 0 (around 10^-8). There should be some pressure gradient. Also, i can't get any visible eddies in the flow field. I know my mesh isn't that fine but i guess there should be something to see. Could you help me with this situation? Initial conditions for p,U, and nut are given as can be seen below.

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2012 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
inlet
{
type cyclic;
}

outlet
{
type cyclic;

}

upperWall
{
type zeroGradient;
}

lowerWall
{
type zeroGradient;
}

leftWall
{
type cyclic;
}

rightWall
{
type cyclic;
}
}

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

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2012 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform (3.7 0 0);

boundaryField
{
inlet
{
type cyclic;
}

outlet
{
type cyclic;
}

upperWall
{
type noSlip;
}

lowerWall
{
type noSlip;
}

leftWall
{
type cyclic;
}

rightWall
{
type cyclic;
}
}

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

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2012 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -1 0 0 0 0];

internalField uniform 0;

boundaryField
{
inlet
{
type cyclic;
}

outlet
{
type cyclic;
}

upperWall
{
type zeroGradient;
}

lowerWall
{
type zeroGradient;
}

leftWall
{
type cyclic;
}

rightWall
{
type cyclic;
}
}

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

I used meanVelocityForce in fvSolutions as seen below.

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2012 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object fvOptions;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

momentumSource
{
type meanVelocityForce;
active yes;

meanVelocityForceCoeffs
{
selectionMode all;

fields (U);
Ubar (3.7 0 0);
}
}


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

Thank you in advance.
Regards,