[Strajesko]

Hello everyone,


I'm actually running a simulation for a Poiseuille flow on a modified version of icoFoam that contain a scalar transport.


When I try to impose a BC at the inlet for the scalar field I encounter some interpolation probem with the other BC (zeroGradient) imposed on the walls :bc.jpg


As you cas see, instead of staying at 0, the scalar value goes up to 0.65 at the bottom and the top wall.


I coded the BC like this :

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2206                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      C;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0.13;

boundaryField
{
    top
    {
        type            zeroGradient;
    }

    floor
    {
        type            zeroGradient;
    }

    Inlet
    {
        type            codedFixedValue;
        value           uniform 0.;
        name            poiseuille;


        code
        #{
          const vectorField& Cf = patch().Cf();
          scalarField& field = *this;
          
          const scalar p0 = 1.52818931e-01;
          const scalar p1 = 1.09857452e-02 ;
          const scalar p2 = 1.14534928e-04 ;
          const scalar p3 = -5.58183299e-05;
          const scalar p4 = -3.93447609e-05;
          
          forAll(Cf, faceI)
          {
              const scalar y = Cf[faceI][1];
              
      
              field[faceI] = (p0+p1*y*1e6+p2*pow(y*1e6,2)+p3*pow(y*1e6,3)+p4*pow(y*1e6,4))*(erf(y*1e6+5)+erf(-y*1e6+6))/2+(erf(y*1e6+4)+erf(-y*1e6+6))/10*(1-(erf(y*1e6+5)+erf(-y*1e6+6))/2);
              
              
              

          }
        #};
    }
    

    Outlet
    {
    type         zeroGradient;
    }

    frontAndBack
    {
        type            empty;
    }
}


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

Do you know how I could solve this issue ?


Thanks in advance