83 lines
2.4 KiB
C++
83 lines
2.4 KiB
C++
|
/*---------------------------------------------------------------------------*\
|
||
|
|
========= |
|
||
|
|
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
|
||
|
|
\\ / O peration |
|
||
|
|
\\ / A nd | Copyright (C) 2004-2010 OpenCFD Ltd.
|
||
|
|
\\/ M anipulation |
|
||
|
|
-------------------------------------------------------------------------------
|
||
|
|
License
|
||
|
|
This file is part of OpenFOAM.
|
||
|
|
|
||
|
|
OpenFOAM is free software: you can redistribute it and/or modify it
|
||
|
|
under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation, either version 3 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
|
||
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
||
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
||
|
|
for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
|
||
|
|
|
||
|
|
Global
|
||
|
|
setDeltaT
|
||
|
|
|
||
|
|
Description
|
||
|
|
Reset the timestep to maintain a low number of Picard iteration and a good
|
||
|
|
convergence. Reduction of time-step is immediate, but increase is damped to
|
||
|
|
avoid unstable oscillations.
|
||
|
|
|
||
|
|
\*---------------------------------------------------------------------------*/
|
||
|
|
|
||
|
|
scalar deltaTFact = 1.;
|
||
|
|
|
||
|
|
if (adjustTimeStep)
|
||
|
|
{
|
||
|
|
deltaTFact = 1.;
|
||
|
|
|
||
|
|
// If There is a too high number of Picard iteration, decrease of the time
|
||
|
|
// step.
|
||
|
|
if (currentPicard > nIterPicard-2)
|
||
|
|
{
|
||
|
|
deltaTFact = 1./tFact;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (currentPicard >= 3)
|
||
|
|
{
|
||
|
|
sc = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if ((currentPicard < 3) && (sc < stabilisationThreshold))
|
||
|
|
{
|
||
|
|
sc = sc+1;
|
||
|
|
}
|
||
|
|
|
||
|
|
// If there is more than 'stabilisationThreshold' iteration that the number
|
||
|
|
// of Picard iteration is low, increase of the time step.
|
||
|
|
if ((currentPicard < 3) && (sc == stabilisationThreshold))
|
||
|
|
{
|
||
|
|
deltaTFact = tFact;
|
||
|
|
sc = 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Reset of the time step if needed (time step is always lower than
|
||
|
|
// 'maxDeltaT').
|
||
|
|
if (deltaTFact != 1.)
|
||
|
|
{
|
||
|
|
runTime.setDeltaT
|
||
|
|
(
|
||
|
|
min
|
||
|
|
(
|
||
|
|
deltaTFact*runTime.deltaTValue(),
|
||
|
|
maxDeltaT
|
||
|
|
)
|
||
|
|
);
|
||
|
|
}
|
||
|
|
|
||
|
|
Info<< "deltaT = " << runTime.deltaTValue() << endl;
|
||
|
|
}
|
||
|
|
|
||
|
|
// ************************************************************************* //
|