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Change top-level AMG solver

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This commit is contained in:
Hrvoje Jasak 2017-11-16 15:22:45 +00:00
parent 9cfd7cbe66
commit 0919f0d590
1 changed files with 20 additions and 37 deletions
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57
src/lduSolvers/amg/coarseAmgLevel.C
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@ -34,7 +34,8 @@ Author
#include "coarseAmgLevel.H" #include "coarseAmgLevel.H"
#include "SubField.H" #include "SubField.H"
#include "gmresSolver.H" #include "cgSolver.H"
#include "bicgStabSolver.H"
#include "vector2D.H" #include "vector2D.H"
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * // // * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
@ -195,30 +196,30 @@ void Foam::coarseAmgLevel::solve
label maxIter = Foam::min(2*policyPtr_->minCoarseEqns(), 1000); label maxIter = Foam::min(2*policyPtr_->minCoarseEqns(), 1000);
dictionary topLevelDict; dictionary topLevelDict;
topLevelDict.add("nDirections", "5");
topLevelDict.add("minIter", 1); topLevelDict.add("minIter", 1);
topLevelDict.add("maxIter", maxIter); topLevelDict.add("maxIter", maxIter);
topLevelDict.add("tolerance", tolerance); topLevelDict.add("tolerance", tolerance);
topLevelDict.add("relTol", relTol); topLevelDict.add("relTol", relTol);
// Avoid issues with round-off on strict tolerance setup
// HJ, 27/Jun/2013
x = b/matrixPtr_->matrix().diag();
// Do not solve if the number of equations is smaller than 5
if (policyPtr_->minCoarseEqns() < 5)
{
return;
}
// Switch off debug in top-level direct solve // Switch off debug in top-level direct solve
label oldDebug = lduMatrix::debug(); label oldDebug = blockLduMatrix::debug();
if (blockLduMatrix::debug >= 4)
{
blockLduMatrix::debug = 1;
}
else
{
blockLduMatrix::debug = 0;
}
if (matrixPtr_->matrix().symmetric()) if (matrixPtr_->matrix().symmetric())
{ {
topLevelDict.add("preconditioner", "Cholesky"); // Note: must change preconditioner to C0. HJ. 10/Oct/2017
// topLevelDict.add("preconditioner", "Cholesky");
topLevelDict.add("preconditioner", "ILUC0");
coarseSolverPerf = gmresSolver coarseSolverPerf = cgSolver
( (
"topLevelCorr", "topLevelCorr",
matrixPtr_->matrix(), matrixPtr_->matrix(),
@ -230,9 +231,9 @@ void Foam::coarseAmgLevel::solve
} }
else else
{ {
topLevelDict.add("preconditioner", "ILU0"); topLevelDict.add("preconditioner", "ILUC0");
coarseSolverPerf = gmresSolver coarseSolverPerf = bicgStabSolver
( (
"topLevelCorr", "topLevelCorr",
matrixPtr_->matrix(), matrixPtr_->matrix(),
@ -244,27 +245,9 @@ void Foam::coarseAmgLevel::solve
} }
// Restore debug // Restore debug
lduMatrix::debug = oldDebug; blockLduMatrix::debug = oldDebug;
// Escape cases of top-level solver divergence if (blockLduMatrix::debug >= 3)
if
(
coarseSolverPerf.nIterations() == maxIter
&& (
coarseSolverPerf.finalResidual()
>= coarseSolverPerf.initialResidual()
)
)
{
// Top-level solution failed. Attempt rescue
// HJ, 27/Jul/2013
x = b/matrixPtr_->matrix().diag();
// Print top level correction failure as info for user
coarseSolverPerf.print();
}
if (lduMatrix::debug >= 3)
{ {
coarseSolverPerf.print(); coarseSolverPerf.print();
} }