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License
    This file is part of OpenFOAM.

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    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.

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    You should have received a copy of the GNU General Public License
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Class
    Foam::functionObjects::adjustTimeStepToReaction

Description
    Returns the minimum bulk reaction time scale

    This allows the solver to temporally resolve chemical changes, in order to
    better couple the chemistry and transport, or to improve the time-accuracy
    of post-processing.

    Note that this function only does anything if time step adjustment is
    enabled in the controlDict.

    Example of function object specification:
    \verbatim
    adjustTimeStepToReaction
    {
        type            adjustTimeStepToReaction;
        libs            ("libreactionModels.so");
        maxCo           0.1;
        extrapolate     no;
    }
    \endverbatim

Usage
    \table
        Property     | Description             | Required    | Default value
        type         | type name: adjustTimeStepToReaction | yes |
        phase        | name of the reacting phase | no       |
        maxCo        | maximum reaction "Courant" number | no | 1
        extrapolate  | try to extrapolate decreases | no     | false
    \endtable

SourceFiles
    adjustTimeStepToReaction.C

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

#ifndef adjustTimeStepToReaction_functionObject_H
#define adjustTimeStepToReaction_functionObject_H

#include "regionFunctionObject.H"
#include "timeIOdictionary.H"

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

namespace Foam
{
namespace functionObjects
{

/*---------------------------------------------------------------------------*\
                  Class adjustTimeStepToReaction Declaration
\*---------------------------------------------------------------------------*/

class adjustTimeStepToReaction
:
    public regionFunctionObject
{
    // Private Data

        //- Name of the phase
        word phaseName_;

        //- Maximum reaction "Courant" number. The maximum fraction of the
        //  total reaction time-scale that should be evolved in a single
        //  time-step.
        scalar maxCo_;

        //- Extrapolate reductions in time-step to try and better catch the
        //  "onset" of reaction. Can lead to time-step oscillation.
        bool extrapolate_;

        //- Do we have the previous reaction time-step?
        mutable bool haveReactionDeltaT0_;

        //- The previous reaction time-step
        mutable scalar reactionDeltaT0_;


    // Private Member Functions

        //- Get the properties dictionary IO object
        typeIOobject<timeIOdictionary> propsDictIo
        (
            const IOobject::readOption& r
        ) const;

public:

    //- Runtime type information
    TypeName("adjustTimeStepToReaction");


    // Constructors

        //- Construct from components
        adjustTimeStepToReaction
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );

        //- Disallow default bitwise copy construction
        adjustTimeStepToReaction(const adjustTimeStepToReaction&) = delete;


    // Destructor
    virtual ~adjustTimeStepToReaction();


    // Member Functions

        //-  Read and reset the timeStep Function1
        virtual bool read(const dictionary&);

        //- Return the list of fields required
        virtual wordList fields() const
        {
            return wordList::null();
        }

        //- Do nothing
        virtual bool execute();

        //- Do nothing
        virtual bool write();

        //- Return the minimum reaction time-scale
        virtual scalar maxDeltaT() const;


    // Member Operators

        //- Disallow default bitwise assignment
        void operator=(const adjustTimeStepToReaction&) = delete;
};


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

} // End namespace functionObjects
} // End namespace Foam

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

#endif

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