setDeltaT.H

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License
    This file is part of OpenFOAM.
 
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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 (adjustTimeStep)
{
    const scalar maxAlphaCo
    (
        runTime.controlDict().lookup<scalar>("maxAlphaCo")
    );
 
    scalar deltaT = 1.2*runTime.deltaTValue();
 
    if (CoNum > small)
    {
        deltaT = min(deltaT, runTime.deltaTValue()*maxCo/CoNum);
    }
 
    if (alphaCoNum > small)
    {
        deltaT = min(maxAlphaCo/alphaCoNum*runTime.deltaTValue(), deltaT);
    }
 
    deltaT = min(min(deltaT, fvModels.maxDeltaT()), maxDeltaT);
 
    runTime.setDeltaT(deltaT);
 
    Info<< "deltaT = " <<  runTime.deltaTValue() << endl;
}
 
// ************************************************************************* //