| /*---------------------------------------------------------------------------*\ | |
| ========= | | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | |
| \\ / O peration | Website: https://openfoam.org | |
| \\ / A nd | Copyright (C) 2022-2026 OpenFOAM Foundation | |
| \\/ 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/>. | |
| \*---------------------------------------------------------------------------*/ | |
| // * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * // | |
| void Foam::solvers::VoFSolver::setRDeltaT() | |
| { | |
| volScalarField& rDeltaT = trDeltaT.ref(); | |
| const dictionary& pimpleDict = pimple.dict(); | |
| const scalar maxCo | |
| ( | |
| pimpleDict.lookupOrDefault<scalar>("maxCo", 0.9) | |
| ); | |
| const volScalarField rDeltaT0("rDeltaT0", rDeltaT); | |
| // Set the reciprocal time-step from the local Courant number | |
| rDeltaT.internalFieldRef() = fvi::surfaceSum(mag(phi))/((2*maxCo)*mesh.V()); | |
| // Clip to user-defined maximum and minimum time-steps | |
| scalar minRDeltaT = gMin(rDeltaT.primitiveField()); | |
| if (pimpleDict.found("maxDeltaT") || minRDeltaT < rootVSmall) | |
| { | |
| const scalar clipRDeltaT = 1/pimpleDict.lookup<scalar>("maxDeltaT"); | |
| rDeltaT.primitiveFieldRef().boundLower(clipRDeltaT); | |
| minRDeltaT = max(minRDeltaT, clipRDeltaT); | |
| } | |
| if (pimpleDict.found("minDeltaT")) | |
| { | |
| const scalar clipRDeltaT = 1/pimpleDict.lookup<scalar>("minDeltaT"); | |
| rDeltaT.primitiveFieldRef().boundUpper(clipRDeltaT); | |
| minRDeltaT = min(minRDeltaT, clipRDeltaT); | |
| } | |
| Info<< "Flow time scale min/max = " | |
| << gMin(1/rDeltaT.primitiveField()) << ", " << 1/minRDeltaT << endl; | |
| setInterfaceRDeltaT(rDeltaT); | |
| // Limit rate of change of time scale | |
| // - reduce as much as required | |
| // - only increase at a fraction of old time scale | |
| if | |
| ( | |
| pimpleDict.found("rDeltaTDampingCoeff") | |
| && runTime.timeIndex() > runTime.startTimeIndex() + 1 | |
| ) | |
| { | |
| // Damping coefficient (1-0) | |
| const scalar rDeltaTDampingCoeff | |
| ( | |
| pimpleDict.lookup<scalar>("rDeltaTDampingCoeff") | |
| ); | |
| rDeltaT = max | |
| ( | |
| rDeltaT, | |
| (scalar(1) - rDeltaTDampingCoeff)*rDeltaT0 | |
| ); | |
| Info<< "Damped flow time scale min/max = " | |
| << gMin(1/rDeltaT.primitiveField()) | |
| << ", " << gMax(1/rDeltaT.primitiveField()) << endl; | |
| } | |
| } | |
| // ************************************************************************* // | |