CFD Online Discussion Forums - Sum over non-boundary cells

Quote:

Originally Posted by Soder (Post 365029)

Hi,
I would like to make a post-process skript where I sum only non-boundary cell values. Does anyone know how this can be done?

Example mass (pseudo-code)

forAll(mesh.V(), celli)
{
if cell != boundaryCell
{
mass = (mesh.V()[celli]*rho[celli]);forAll(mesh.V(), celli)
massSum += mass;
}
}

best regards
Martin Soder

Just an idea (no code):

Create a list of bools for each cell of your mesh and mark each with "true", for example,

Code:

 

PackedBoolList isInterior(mesh.nCells(), true);

Loop over the boundary faces, marking the cell owner (which is a boundary cell) as being non-interior:

Code:

const labelUList& owner = mesh.faceOwner();

for (label faceI=mesh.nInternalFaces(); faceI < mesh.nFaces(); ++faceI)

{

     isInterior.unset(owner[faceI]);

     //OR isInterior.set(owner[faceI], false);

}

The cells in isInterior that are still 'true' must be your interior cells.
The easiest is probably to use this as a mask when iterating over all cells:

Code:

forAll(mesh.V(), cellI)

{

    if (isInterior[cellI])

    {

    ...

    }

}

There may be a more elegant way, but this should at least get you going.