[GCMS_A]

Hi everyone,

I have this code that I would like to modify to fit to my problem :

// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void velocityChannelWallFunctionFvPatchField::updateCoeffs()
{
    if (this->updated())
    {
        return;
    }

//  Set up access to the mesh
    const fvMesh& mesh = patch().boundaryMesh().mesh();

//  Set up access to the internal velocity field.
    const volVectorField& UCell = db().objectRegistry::lookupObject<volVectorField>("U");

//  Interpolate velocity on the cell faces.
    surfaceVectorField UFace = fvc::interpolate(UCell);


//  Get face areas (individual and global sum) (note that "gSum" is used as
//  opposed to "sum" because "gSum" is parallel-aware --- it gathers sums from
//  each processor to which this patch belongs and makes the global sum)
    const scalarField area = patch().magSf();
    scalar areaTotal = gSum(area);
//  Get perpendicular distance from cell center to boundary.  In other words,
//  the height of the y_1/2 grid level.
    const scalarField y12 = 1.0/patch().deltaCoeffs();

//  Get face normal vectors
    vectorField normal = patch().nf();

I have modified it like this :

// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void velocityChannelWallFunctionFvPatchField::updateCoeffs()
{
    if (this->updated())
    {
        return;
    }

//  Set up access to the mesh
    const fvMesh& mesh = patch().boundaryMesh().mesh();

//  --------

    label patchIndexUp = mesh.boundaryMesh().findPatchID("topWall");
    Info << "patchIndexUp =" << patchIndexUp << endl; 

    label patchIndexDown = mesh.boundaryMesh().findPatchID("bottomWall");
    Info << "patchIndexDown =" << patchIndexDown << endl; 

//  --------



//  Set up access to the internal velocity field.
    const volVectorField& UCell = db().objectRegistry::lookupObject<volVectorField>("U");

//  Interpolate velocity on the cell faces.
    surfaceVectorField UFace = fvc::interpolate(UCell);


//  Get face areas (individual and global sum) (note that "gSum" is used as
//  opposed to "sum" because "gSum" is parallel-aware --- it gathers sums from
//  each processor to which this patch belongs and makes the global sum)
    const scalarField area = patch().magSf();
    scalar areaTotal = gSum(area);
//  Get perpendicular distance from cell center to boundary.  In other words,
//  the height of the y_1/2 grid level.
    const scalarField y12 = 1.0/patch().deltaCoeffs();

//  Get face normal vectors
    vectorField normal = patch().nf();

but I don't know how can I get the area, face normal vectors ... of the patchIndexUp & the patchIndexDown.

If anybody know how to do this, I would be very happy to have explanations.

Thank you

Anass

[GCMS_A]

Hi everyone,
I finaly found how to get the face area for the two patches (patchIndexUp & Down).

My code became as follow :

// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

void velocityChannelWallFunctionFvPatchField::updateCoeffs()
{
    if (this->updated())
    {
        return;
    }

//  Set up access to the mesh
    const fvMesh& mesh = patch().boundaryMesh().mesh();

//  --------

    label patchIndexUp = mesh.boundaryMesh().findPatchID("topWall");
    Info << "patchIndexUp =" << patchIndexUp << endl; 

    label patchIndexDown = mesh.boundaryMesh().findPatchID("bottomWall");
    Info << "patchIndexDown =" << patchIndexDown << endl; 

//  --------



//  Set up access to the internal velocity field.
    const volVectorField& UCell = db().objectRegistry::lookupObject<volVectorField>("U");

//  Interpolate velocity on the cell faces.
    surfaceVectorField UFace = fvc::interpolate(UCell);


//  Get face areas (individual and global sum) (note that "gSum" is used as
//  opposed to "sum" because "gSum" is parallel-aware --- it gathers sums from
//  each processor to which this patch belongs and makes the global sum)
//  const scalarField area = patch().magSf();
//  scalar areaTotal = gSum(area);


//  --------
    const surfaceScalarField& magSf = mesh.magSf();
    scalar areaUpTotal = gSum(magSf.boundaryField()[patchIndexUp]);
    scalar areaDownTotal = gSum(magSf.boundaryField()[patchIndexDown]);
//  --------

//  Get perpendicular distance from cell center to boundary.  In other words,
//  the height of the y_1/2 grid level.
    //const scalarField y12 = 1.0/patch().deltaCoeffs();


//  --------
    const scalarField yUp = mesh.boundary()[patchIndexUp].deltaCoeffs();
    const scalarField yDown = mesh.boundary()[patchIndexDown].deltaCoeffs();
//  --------

//  Get face normal vectors
    //vectorField normal = patch().nf();

//  --------
    vectorField normalUp = mesh.Sf().boundaryField()[patchIndexUp];
    vectorField normalDown = mesh.Sf().boundaryField()[patchIndexDown];

My question now is : For this part of code :

//  Set up access to the internal velocity field.
    const volVectorField& UCell = db().objectRegistry::lookupObject<volVectorField>("U");

//  Interpolate velocity on the cell faces.
    surfaceVectorField UFace = fvc::interpolate(UCell);

Is someone could explain to me the meaning of these lines of code ? and how can I change them if I want to find the values ​​of Ucell and UFace for the patchIndexUp and patchIndexDown ?


Thank you

Anass

[pvpnrao]

GCMS_A

Thank you very much for posting the fix for calculating the areas of other boundaries within a boundary condition.

You saved me a lot of time today. I understand your query in in the second post is three years old. I am sure you must have figured it.

Let me know if you still need this information.