[fshak92]

Hi,

Assume that i have a simple cubic domain with Cartesian grids.
Does anybody know how i can access these values, either with a function, or accessing to the 'blockMeshDict' file.

1) number of cells in each direction. I know mesh.nCells() or mesh.cells().size() returns the total number of cells, but i need the number in each direction.

2) length of the domain (x, y and z)

3) length of cells edges in each direction to have dx, dy and dz.(the cells are uniform in each direction)
(at the moment, i compute dx, dy and dz by computing the distance between cell's centers, but i'm looking for any other ways)

Of course, either (1) or (2) can solve my problem, because having two of those three cases can be used to evaluate the remained one.

Tnx,

[chrisb2244]

If you have access to the polyMesh object, then

 meshObject.edges()[edgeLabel].mag()

returns the scalar length of the edge indexed by the variable 'edgeLabel'. If your edges are all the same length, then that should sort your problems. If only your edges in each direction are the same, then you'll need an edge for each direction.

Using

 labelList listOfCellEdges(meshObject.cEdges()[cellLabel]);
forAll(listOfCellEdges, edgeI)
{
   // Iterate through the edges of cellI, which if your cells are uniform,
   // can be any cell
   // Use meshObject.edges()[edgeI].vec() to get the vector along the edge, or 
   // meshObject.edges()[edgeI].mag() to get it's magnitude.
}

Comparing these with the directions you're interested in shouldn't be too hard, I don't think. Then you just need to selectively store the ones you're interested in (eg first x, first y, first z direction).


If your region is cube/cuboid, then you can get the range of the directions by taking

vector extent(mesh_.cellCentres[mesh_.nCells()] - mesh_.cellCentres[0]);
extent += vector(dx, dy, dz) // where dx,y,z are set already, 
// since these take cell centres...
scalar sizeInXDirection = extent[0]; //etc

[jhoepken]

Are you trying to replicate a structured code on the unstructured FV method, implemented in OpenFOAM?

[fshak92]

Originally Posted by jhoepken

Are you trying to replicate a structured code on the unstructured FV method, implemented in OpenFOAM?

No,for different purpose.