82 lines
2.5 KiB
C++
82 lines
2.5 KiB
C++
/*---------------------------------------------------------------------------*\
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========= |
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\\ / F ield | foam-extend: Open Source CFD
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\\ / O peration | Version: 4.1
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\\ / A nd | Web: http://www.foam-extend.org
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\\/ M anipulation | For copyright notice see file Copyright
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-------------------------------------------------------------------------------
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License
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This file is part of foam-extend.
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foam-extend is free software: you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation, either version 3 of the License, or (at your
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option) any later version.
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foam-extend is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with foam-extend. If not, see <http://www.gnu.org/licenses/>.
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Global
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setDeltaT
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Description
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Reset the timestep to maintain a low number of Picard iteration and a good
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convergence. Reduction of time-step is immediate, but increase is damped to
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avoid unstable oscillations.
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\*---------------------------------------------------------------------------*/
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scalar deltaTFact = 1.;
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if (adjustTimeStep)
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{
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deltaTFact = 1.;
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// If There is a too high number of Picard iteration, decrease of the time
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// step.
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if (currentPicard > nIterPicard-2)
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{
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deltaTFact = 1./tFact;
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}
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if (currentPicard >= 3)
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{
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sc = 0;
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}
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if ((currentPicard < 3) && (sc < stabilisationThreshold))
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{
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sc = sc+1;
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}
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// If there is more than 'stabilisationThreshold' iteration that the number
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// of Picard iteration is low, increase of the time step.
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if ((currentPicard < 3) && (sc == stabilisationThreshold))
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{
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deltaTFact = tFact;
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sc = 0;
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}
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// Reset of the time step if needed (time step is always lower than
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// 'maxDeltaT').
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if (deltaTFact != 1.)
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{
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runTime.setDeltaT
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(
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min
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(
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deltaTFact*runTime.deltaTValue(),
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maxDeltaT
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)
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);
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}
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Info<< "deltaT = " << runTime.deltaTValue() << endl;
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}
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// ************************************************************************* //
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