openfoam/etc/caseDicts/annotated/decomposeParDict

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2106                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    note        "mesh decomposition control dictionary";
    object      decomposeParDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

//- The total number of domains (mandatory)
numberOfSubdomains  256;

//- The decomposition method (mandatory)
method          scotch;
// method          hierarchical;
// method          simple;
// method          metis;
// method          manual;
// method          multiLevel;
// method          structured;  // does 2D decomposition of structured mesh


//- Optional region-wise decomposition.
//  Can specify a different method.
//  The number of subdomains can be less than the top-level numberOfSubdomains.
regions
{
    water
    {
        numberOfSubdomains 128;
        method  metis;
    }

    ".*solid"
    {
        numberOfSubdomains 4;
        method  metis;
    }

    heater
    {
        numberOfSubdomains 1;
        method  none;
    }
}


// Coefficients for the decomposition method are either as a general
// "coeffs" dictionary or method-specific "<method>Coeffs".
// For multiLevel, using multiLevelCoeffs only.

multiLevelCoeffs
{
    // multiLevel decomposition methods to apply in turn.
    // This is like hierarchical but fully general
    // - every method can be used at every level.

    // Only sub-dictionaries containing the keyword "method" are used.
    //

    level0
    {
        numberOfSubdomains  16;
        method  scotch;
    }
    level1
    {
        numberOfSubdomains  2;
        method  scotch;
        coeffs
        {
            n       (2 1 1);
            delta   0.001;
        }
    }
    level2
    {
        numberOfSubdomains  8;
        // method  simple;
        method  scotch;
    }
}


multiLevelCoeffs
{
    // Compact multiLevel specification, activated by the presence of the
    // keywords "method" and "domains"

    method  scotch;
    domains (16 2 8);

    //// Or with implicit '16' for the first level with numberOfSubdomains=256
    //domains (2 8);
}



// Other example coefficients

coeffs
{
    n       (2 1 1);
}

simpleCoeffs
{
    n       (2 1 1);
    // delta   0.001;  //< default value = 0.001
}

hierarchicalCoeffs
{
    n       (1 2 1);
    // delta   0.001;  //< default value = 0.001
    // order   xyz;    //< default order = xyz
}

metisCoeffs
{
 /*
    processorWeights
    (
        1
        1
        1
        1
    );
  */
}

scotchCoeffs
{
    //processorWeights
    //(
    //    1
    //    1
    //    1
    //    1
    //);
    //writeGraph  true;
    //strategy "b";
}

manualCoeffs
{
    dataFile    "decompositionData";
}

structuredCoeffs
{
    // Patches to do 2D decomposition on. Structured mesh only; cells have
    // to be in 'columns' on top of patches.
    patches     (movingWall);

    // Method to use on the 2D subset
    method      scotch;
}


//- Use the volScalarField named here as a weight for each cell in the
//  decomposition.  For example, use a particle population field to decompose
//  for a balanced number of particles in a lagrangian simulation.
// weightField dsmcRhoNMean;


//// Is the case distributed? Note: command-line argument -roots takes
//// precedence
//distributed     yes;
//
//// Per slave (so nProcs-1 entries) the directory above the case.
//roots
//(
//    "/tmp"
//    "/tmp"
//);


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// Decomposition constraints

/*
constraints
{
    baffles
    {
        //- Keep owner and neighbour of baffles on same processor (i.e.
        // keep it detectable as a baffle). Baffles are two boundary face
        // sharing the same points
        type    preserveBaffles;
        enabled false;
    }
    faces
    {
        //- Keep owner and neighbour on same processor for faces in zones
        type    preserveFaceZones;
        zones   (".*");
        enabled false;
    }
    patches
    {
        //- Keep owner and neighbour on same processor for faces in patches
        //  (only makes sense for cyclic patches and cyclicAMI)
        type    preservePatches;
        patches (".*");
        enabled false;
    }
    processors
    {
        //- Keep all of faceSet on a single processor. This puts all cells
        //  connected with a point, edge or face on the same processor.
        //  (just having face connected cells might not guarantee a balanced
        //  decomposition)
        // The processor can be -1 (the decompositionMethod chooses the
        // processor for a good load balance) or explicitly provided (upsets
        // balance)
        type    singleProcessorFaceSets;
        sets    ((f1 -1));
        enabled false;
    }
    refinement
    {
        //- Decompose cells such that all cell originating from single cell
        //  end up on same processor
        type    refinementHistory;
        enabled false;
    }
    geometric
    {
        type    geometric;

        grow    false;

        selection
        {
            box1
            {
                source  box;
                min     (-0.1 -0.01 -0.1);
                max     (0.1 0.30 0.1);
            }
            ball
            {
                source  sphere;
                origin  (-0.1 -0.01 -0.1);
                radius  0.25;
            }
            blob
            {
                source      surface;
                surfaceType triSurfaceMesh;
                surfaceName blob.obj;
            }
        }
    }
}
*/

// Deprecated form of specifying decomposition constraints:
//- Keep owner and neighbour on same processor for faces in zones:
// preserveFaceZones (heater solid1 solid3);

//- Keep owner and neighbour on same processor for faces in patches:
//  (only makes sense for cyclic patches and cyclicAMI)
//preservePatches (cyclic_half0 cyclic_half1);

//- Keep all of faceSet on a single processor. This puts all cells
//  connected with a point, edge or face on the same processor.
//  (just having face connected cells might not guarantee a balanced
//  decomposition)
// The processor can be -1 (the decompositionMethod chooses the processor
// for a good load balance) or explicitly provided (upsets balance).
//singleProcessorFaceSets ((f0 -1));

//- Keep owner and neighbour of baffles on same processor (i.e. keep it
//  detectable as a baffle). Baffles are two boundary face sharing the
//  same points.
//preserveBaffles true;

// ************************************************************************* //