/*---------------------------------------------------------------------------*\
  ==  == ====== ====   ====    |
                    \\     ||  | Multiphase Code Repository by HZDR
  ======   //   ||  || ===//   | Website: https://doi.org/10.14278/rodare.767
  ||  ||  //    ||  // || \\   | License: GPL-3.0-or-later
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-------------------------------------------------------------------------------
License
    This file is part of the Multiphase Code Repository by HZDR.

    Copyright (C) 2025 by Helmholtz-Zentrum Dresden-Rossendorf e.V. (HZDR),
    Website: https://hzdr.de

    Multiphase Code Repository by HZDR is based on the free software for
    computational fluid dynamics (CFD) from the OpenFOAM Foundation.
    Copyright (C) 2025 by OpenFOAM Foundation, Website: https://openfoam.org

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    Multiphase Code Repository by HZDR is free software: you can redistribute
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#include "Syamlal.H"
#include "phaseSystem.H"
#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
namespace dragModels
{
    defineTypeNameAndDebug(Syamlal, 0);
    addToRunTimeSelectionTable(dragModel, Syamlal, dictionary);
}
}


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

Foam::dragModels::Syamlal::Syamlal
(
    const dictionary& dict,
    const phaseInterface& interface,
    const bool registerObject
)
:
    dragModel(dict, interface, registerObject),
    interface_(interface),
    continuousPhase_(dict.lookup("continuousPhase")),
    e_("e", dimless, dict),
    Cf_("Cf", dimless, dict)
{}


// * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //

Foam::dragModels::Syamlal::~Syamlal()
{}


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

Foam::tmp<Foam::volScalarField>
Foam::dragModels::Syamlal::K() const
{
    const phaseModel& solid1 = interface_.phase1();
    const phaseModel& solid2 = interface_.phase2();
    const phaseModel& continuous =
        interface_.fluid().phases()[continuousPhase_];

    const volScalarField magURel(mag(solid1.U() - solid2.U()));

    const volScalarField alphaCLimited
    (
        max(continuous, continuous.residualAlpha())
    );

    const volScalarField d1(solid1.d());
    const volScalarField d2(solid2.d());

    const volScalarField g0
    (
        1.0/alphaCLimited
      + 3.0*(solid1/d1 + solid2/d2)*d1*d2
       /(
            sqr(alphaCLimited)*(d1 + d2)
        )
    );

    const scalar pi(Foam::constant::mathematical::pi);

    return
        3.0
       *(1.0 + e_)
       *(pi/2.0 + Cf_*sqr(pi)/8.0)
       *solid1*solid1.rho()*solid2*solid2.rho()
       *sqr(d1 + d2)
       *g0
       *magURel
       /(
            2.0*pi*(solid1.rho()*pow(d1, 3) + solid2.rho()*pow(d2, 3))
        );
}


Foam::tmp<Foam::surfaceScalarField>
Foam::dragModels::Syamlal::Kf() const
{
    return fvc::interpolate(K());
}


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