[Jamill1283]

Hi Foamers,

I am trying to use and understand magSf() function to calculate the individual surface area of a cell. I am constructed a simple code like this to understand the face area;

for (label cellI = 0;cellI < mesh.C().size(); cellI++)
  {
    if (cellI == 321)
    {
      for (label faceI = 0; faceI < mesh.Cf()[cellI].size(); faceI++)
        {
           Info << "The surface area for the faces of number " << mesh.Cf()[cellI].size() << " at face " 
                << faceI << " on " << " cell "<< cellI  <<" is: " << mesh.magSf()[faceI] << endl;
         
                
           Info << "Cell connectivity:  " << mesh.cellCells()[cellI] << endl;
                               
         }
     }
  }

However, when I run this code on a simple 2D Lid cavity case, I obtained a surface area that is twice as what I manually calculated. Moreover, the size() function also return only 3 faces for a simple hexahedral mesh, although mesh connectivity calculated return 4 cells surrounding the cells pointed.

For your information, the domain size is 0.1m x 0.1m and is discretized into (20 20 1). Taking one cell, the cell size is 5e-3m x 5e-3m, which means the area is 2.5e-5m2. However, magSf returned 5e-5m2 for the face pointed, which is essentially twice the face area.

Anyway, I tried this for 3D case and the area returned is correct, although the size() function still return 3 faces although mesh connectivity return 6 mesh surrounding cells pointed.

I am really confused with this behavior and hope someone can help me to understand it.


Thanks,