/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011 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/>.

Global
    setDeltaT

Description
    Reset the timestep to maintain a constant maximum courant Number.
    Reduction of time-step is immediate, but increase is damped to avoid
    unstable oscillations.

\*---------------------------------------------------------------------------*/

if (pulseTimeStep)
{
    const scalar t = runTime.timeOutputValue();
    const scalar T = pulsePeriod;
    const scalar neg_saw_t = (t - floor(t/T+1.)*T);

    const bool inPulse = neg_saw_t >= -pulseTime;

    if (inPulse)
    {
        runTime.setDeltaT (deltaTpulse);
        Info<< "deltaT to proceed the pulse time " << endl;
    }
    else
    {
        const scalar eta = - pulseTime - neg_saw_t;

        if (eta >= deltaTidle)
        {
            runTime.setDeltaT (deltaTidle);
            Info<< "deltaT to proceed the idle time " << endl;
        }
        else
        {
            runTime.setDeltaT (deltaTpulse);
            Info<< "deltaT to the start of the pulse " << endl;
        }

    }


    Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
}
else if (adjustTimeStep)
{
    CoNum = max(CoNum, CoNumVe);
    scalar maxDeltaTFact = maxCo/(CoNum + SMALL);
    scalar deltaTFact = min(min(maxDeltaTFact, 1.0 + 0.1*maxDeltaTFact), 1.2);

    runTime.setDeltaT
    (
        min
        (
            deltaTFact*runTime.deltaTValue(),
            maxDeltaT
        )
    );

    Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
}

// ************************************************************************* //