This view factors generation application uses a combined approach of double area integral (2AI) and double linear integral (2LI). 2AI is used when the two surfaces are 'far' apart and 2LI when they are 'close'. 2LI is integrated along edges using Gaussian quadrature. The distance between faces is calculating a ratio between averaged areas and the distance between face centres. More...

Detailed Description

This view factors generation application uses a combined approach of double area integral (2AI) and double linear integral (2LI). 2AI is used when the two surfaces are 'far' apart and 2LI when they are 'close'. 2LI is integrated along edges using Gaussian quadrature. The distance between faces is calculating a ratio between averaged areas and the distance between face centres.

Original source file viewFactorsGen.C

The input from viewFactorsDict are:

    GaussQuadTol              0.1;      // GaussQuad  error
    distTol                   8;        // R/Average(rm)
    alpha                     0.22;     // Use for common edges for 2LI

For debugging purposes, the following entries can be set in viewFactorsDict:

    writeViewFactorMatrix     true;
    writeFacesAgglomeration   false;
    dumpRays                  false;

    writeViewFactorMatrix   writes the sum of the VF on each face.
    writeFacesAgglomeration writes the agglomeration
    dumpRays                dumps rays

The participating patches in the VF calculation have to be in the 'viewFactorWall' patch group (in the polyMesh/boundary file), e.g.

floor
{
    type            wall;
    inGroups        2(wall viewFactorWall);
    nFaces          100;
    startFace       3100;
}

Compile with -DNO_CGAL only if no CGAL present - CGAL AABB tree performs better than the built-in octree.

Definition in file viewFactorsGen.C.