src/foam/matrices/lduMatrix/solvers/PCG/PCG.C

   1 /*---------------------------------------------------------------------------*\
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   4    \\    /   O peration     | Version:     3.2
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   8 License
   9     This file is part of foam-extend.
  10
  11     foam-extend is free software: you can redistribute it and/or modify it
  12     under the terms of the GNU General Public License as published by the
  13     Free Software Foundation, either version 3 of the License, or (at your
  14     option) any later version.
  15
  16     foam-extend is distributed in the hope that it will be useful, but
  17     WITHOUT ANY WARRANTY; without even the implied warranty of
  18     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19     General Public License for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 \*---------------------------------------------------------------------------*/
  25
  26 #include "PCG.H"
  27
  28 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  29
  30 namespace Foam
  31 {
  32     defineTypeNameAndDebug(PCG, 0);
  33
  34     lduSolver::addsymMatrixConstructorToTable<PCG>
  35         addPCGSymMatrixConstructorToTable_;
  36 }
  37
  38
  39 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  40
  41 Foam::PCG::PCG
  42 (
  43     const word& fieldName,
  44     const lduMatrix& matrix,
  45     const FieldField<Field, scalar>& coupleBouCoeffs,
  46     const FieldField<Field, scalar>& coupleIntCoeffs,
  47     const lduInterfaceFieldPtrsList& interfaces,
  48     const dictionary& dict
  49 )
  50 :
  51     lduSolver
  52     (
  53         fieldName,
  54         matrix,
  55         coupleBouCoeffs,
  56         coupleIntCoeffs,
  57         interfaces,
  58         dict
  59     )
  60 {}
  61
  62
  63 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
  64
  65 Foam::lduSolverPerformance Foam::PCG::solve
  66 (
  67     scalarField& x,
  68     const scalarField& b,
  69     const direction cmpt
  70 ) const
  71 {
  72     // --- Setup class containing solver performance data
  73     lduSolverPerformance solverPerf(typeName, fieldName());
  74
  75     register label nCells = x.size();
  76
  77     scalar* __restrict__ xPtr = x.begin();
  78
  79     scalarField pA(nCells);
  80     scalar* __restrict__ pAPtr = pA.begin();
  81
  82     scalarField wA(nCells);
  83     scalar* __restrict__ wAPtr = wA.begin();
  84
  85     // Calculate A.x
  86     matrix_.Amul(wA, x, coupleBouCoeffs_, interfaces_, cmpt);
  87
  88     // Calculate initial residual field
  89     scalarField rA(b - wA);
  90     scalar* __restrict__ rAPtr = rA.begin();
  91
  92     // Calculate normalisation factor
  93     scalar normFactor = this->normFactor(x, b, wA, pA, cmpt);
  94
  95     if (lduMatrix::debug >= 2)
  96     {
  97         Info<< "   Normalisation factor = " << normFactor << endl;
  98     }
  99
 100     // Calculate normalised residual norm
 101     solverPerf.initialResidual() = gSumMag(rA)/normFactor;
 102     solverPerf.finalResidual() = solverPerf.initialResidual();
 103
 104     // Check convergence, solve if not converged
 105     if (!stop(solverPerf))
 106     {
 107         scalar wArA = matrix_.great_;
 108         scalar wArAold = wArA;
 109
 110         // Select and construct the preconditioner
 111         autoPtr<lduPreconditioner> preconPtr;
 112
 113         preconPtr =
 114             lduPreconditioner::New
 115             (
 116                 matrix_,
 117                 coupleBouCoeffs_,
 118                 coupleIntCoeffs_,
 119                 interfaces_,
 120                 dict()
 121             );
 122
 123         // Rename the solver pefformance to include precon name
 124         solverPerf.solverName() = preconPtr->type() + typeName;
 125
 126         // Solver iteration
 127         do
 128         {
 129             // Store previous wArA
 130             wArAold = wArA;
 131
 132             // Precondition residual
 133             preconPtr->precondition(wA, rA, cmpt);
 134
 135             // Update search directions:
 136             wArA = gSumProd(wA, rA);
 137
 138             if (solverPerf.nIterations() == 0)
 139             {
 140                 for (register label cell=0; cell<nCells; cell++)
 141                 {
 142                     pAPtr[cell] = wAPtr[cell];
 143                 }
 144             }
 145             else
 146             {
 147                 scalar beta = wArA/wArAold;
 148
 149                 for (register label cell=0; cell<nCells; cell++)
 150                 {
 151                     pAPtr[cell] = wAPtr[cell] + beta*pAPtr[cell];
 152                 }
 153             }
 154
 155
 156             // Update preconditioned residual
 157             matrix_.Amul(wA, pA, coupleBouCoeffs_, interfaces_, cmpt);
 158
 159             scalar wApA = gSumProd(wA, pA);
 160
 161
 162             // Test for singularity
 163             if (solverPerf.checkSingularity(mag(wApA)/normFactor)) break;
 164
 165
 166             // Update solution and residual:
 167
 168             scalar alpha = wArA/wApA;
 169
 170             for (register label cell=0; cell<nCells; cell++)
 171             {
 172                 xPtr[cell] += alpha*pAPtr[cell];
 173                 rAPtr[cell] -= alpha*wAPtr[cell];
 174             }
 175
 176             solverPerf.finalResidual() = gSumMag(rA)/normFactor;
 177             solverPerf.nIterations()++;
 178         } while (!stop(solverPerf));
 179     }
 180
 181     return solverPerf;
 182 }
 183
 184
 185 // ************************************************************************* //