GAMGPreconditioner.C

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/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2013 OpenFOAM Foundation
     \\/     M anipulation  |
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License
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#include "GAMGPreconditioner.H"
 
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 
namespace Foam
{
    defineTypeNameAndDebug(GAMGPreconditioner, 0);
 
    lduMatrix::preconditioner::addsymMatrixConstructorToTable
    <GAMGPreconditioner> addGAMGPreconditionerSymMatrixConstructorToTable_;
 
    lduMatrix::preconditioner::addasymMatrixConstructorToTable
    <GAMGPreconditioner> addGAMGPreconditionerAsymMatrixConstructorToTable_;
}
 
 
// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 
Foam::GAMGPreconditioner::GAMGPreconditioner
(
    const lduMatrix::solver& sol,
    const dictionary& solverControls
)
:
    GAMGSolver
    (
        sol.fieldName(),
        sol.matrix(),
        sol.interfaceBouCoeffs(),
        sol.interfaceIntCoeffs(),
        sol.interfaces(),
        solverControls
    ),
    lduMatrix::preconditioner(sol),
    nVcycles_(2)
{
    readControls();
}
 
 
// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
 
Foam::GAMGPreconditioner::~GAMGPreconditioner()
{}
 
 
// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
void Foam::GAMGPreconditioner::readControls()
{
    GAMGSolver::readControls();
    nVcycles_ = controlDict_.lookupOrDefault<label>("nVcycles", 2);
}
 
 
void Foam::GAMGPreconditioner::precondition
(
    scalarField& wA,
    const scalarField& rA,
    const direction cmpt
) const
{
    wA = 0.0;
    scalarField AwA(wA.size());
    scalarField finestCorrection(wA.size());
    scalarField finestResidual(rA);
 
    // Create coarse grid correction fields
    PtrList<scalarField> coarseCorrFields;
 
    // Create coarse grid sources
    PtrList<scalarField> coarseSources;
 
    // Create the smoothers for all levels
    PtrList<lduMatrix::smoother> smoothers;
 
    // Scratch fields if processor-agglomerated coarse level meshes
    // are bigger than original. Usually not needed
    scalarField ApsiScratch;
    scalarField finestCorrectionScratch;
 
    // Initialise the above data structures
    initVcycle
    (
        coarseCorrFields,
        coarseSources,
        smoothers,
        ApsiScratch,
        finestCorrectionScratch
    );
 
    for (label cycle=0; cycle<nVcycles_; cycle++)
    {
        Vcycle
        (
            smoothers,
            wA,
            rA,
            AwA,
            finestCorrection,
            finestResidual,
 
            (ApsiScratch.size() ? ApsiScratch : AwA),
            (
                finestCorrectionScratch.size()
              ? finestCorrectionScratch
              : finestCorrection
            ),
 
            coarseCorrFields,
            coarseSources,
            cmpt
        );
 
        if (cycle < nVcycles_-1)
        {
            // Calculate finest level residual field
            matrix_.Amul(AwA, wA, interfaceBouCoeffs_, interfaces_, cmpt);
            finestResidual = rA;
            finestResidual -= AwA;
        }
    }
}
 
 
// ************************************************************************* //