/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
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    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
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    Copyright (C) 2011-2017 OpenFOAM Foundation
-------------------------------------------------------------------------------
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.

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    for more details.

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// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

inline Foam::TroeFallOffFunction::TroeFallOffFunction
(
    const scalar alpha,
    const scalar Tsss,
    const scalar Ts,
    const scalar Tss
)
:
    alpha_(alpha),
    Tsss_(Tsss),
    Ts_(Ts),
    Tss_(Tss)
{}


inline Foam::TroeFallOffFunction::TroeFallOffFunction(const dictionary& dict)
:
    alpha_(dict.get<scalar>("alpha")),
    Tsss_(dict.get<scalar>("Tsss")),
    Ts_(dict.get<scalar>("Ts")),
    Tss_(dict.get<scalar>("Tss"))
{}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

inline Foam::scalar Foam::TroeFallOffFunction::operator()
(
    const scalar T,
    const scalar Pr
) const
{
    scalar logFcent = log10
    (
        max
        (
            (1 - alpha_)*exp(-T/Tsss_) + alpha_*exp(-T/Ts_) + exp(-Tss_/T),
            SMALL
        )
    );

    scalar c = -0.4 - 0.67*logFcent;
    static const scalar d = 0.14;
    scalar n = 0.75 - 1.27*logFcent;

    scalar logPr = log10(max(Pr, SMALL));
    return pow(10.0, logFcent/(1.0 + sqr((logPr + c)/(n - d*(logPr + c)))));
}


inline void Foam::TroeFallOffFunction::write(Ostream& os) const
{
    os.writeEntry("alpha", alpha_);
    os.writeEntry("Tsss", Tsss_);
    os.writeEntry("Ts", Ts_);
    os.writeEntry("Tss", Tss_);
}


// * * * * * * * * * * * * * * * Ostream Operator  * * * * * * * * * * * * * //

inline Foam::Ostream& Foam::operator<<
(
    Foam::Ostream& os,
    const Foam::TroeFallOffFunction& tfof
)
{
    tfof.write(os);
    return os;
}


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