[be_inspired]

Hi all,

My intention is know where is the cell with the lowest distance to the wall without using paraFoam. It would give me an indication about where is the problem in the mesh and where I have to change the mesh.

           Info<< "Calculating wall distance using wallDist function\n" << endl;
           wallDist y(mesh, true);
           Info<< "Writing wall distance to field zDistance" << endl;
           zDistance.internalField()= y;
           Info << " Minimum z Distance"<< min(zDistance) << endl;
           zDistance.write();
	   Info << "location"<< mesh.findCell(zDistance=??)<< endl;

I have looked for it around the forum but I do not know how to extract the cellID of that specific cell and so, to use the mesh.C() option.

Please, could someone help me.
Thanks.

[ngj]

Hi Marcelino,

As far as I know, you have to do a search for the cell in question. The brute-force solution is simply to do the following (note, just written out, it might be adjusted for compilation):

label cellIndex = 0;

forAll( mesh.C(), celli )
{
    if ( y[celli] < y[cellIndex] )
        cellIndex = celli;
}

Info << "The cell index with smallest distance:" << tab << cellIndex << endl;

This will be a bit slow, so I would suggest simply to search all of the cells along the boundaries. You could e.g. do something like the following:

label cellIndex = 0;

forAll( y.boundaryField(), patchi )
{
    const labelList & faceCells = mesh.boundaryMesh()[patchi].patch().faceCells(); // Something like this, but might not compile.
    
    forAll( faceCells, celli )
    {
        if ( y[faceCells[celli]] < y[cellIndex] )
             cellIndex = faceCells[celli];
    }
}

Info << "The cell index with smallest distance:" << tab << cellIndex << endl;

Kind regards

Niels

[be_inspired]

Hi Niels,

Thank you very much.I have chosen the second option and works great in a mesh of 20 millions of elements. The only point is that, al least for OF2.1.1, I had to delete a patch() word in one of your code lines.

I post the last version here if someone needs the tool or has to modify it for other purposes.

Thanks a lot
Marcelino

int main( int argc, char *argv[])
{
        
# include "setRootCase.H"
# include "createTime.H"
# include "createMesh.H"

           Info<< "Calculating wall distance using wallDist function\n" << endl;
           wallDist y(mesh, true);
           y.write();
           Info<< "Analyzing minimum cell Distance" << endl;
	   label cellIndex=0;
	   forAll ( y.boundaryField(),patchi)
{ 
		const labelList & faceCells = mesh.boundaryMesh()[patchi].faceCells();

		forAll (faceCells, celli)
	{
		if ( y[faceCells[celli]] < y[cellIndex] )
		cellIndex = faceCells[celli];
	}
}

	    Info << "The cell index with smallest distance:" << tab << cellIndex << endl;
	    Info << "Minimum wall distance" << tab << y[cellIndex] << endl;
 	 
	    Info << "Location of the cell with minimum wall distance (X Y Z)" << mesh.C()[cellIndex] << endl;
	
    

    return 0;
}