limitedCubic.H

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/*---------------------------------------------------------------------------*\
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  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2015 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.
 
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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    You should have received a copy of the GNU General Public License
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Class
    Foam::limitedCubicLimiter
 
Description
    Class with limiter function which returns the limiter for the
    TVD limited centred-cubic differencing scheme based on r obtained from
    the LimiterFunc class.
 
    Used in conjunction with the template class LimitedScheme.
 
SourceFiles
    limitedCubic.C
 
\*---------------------------------------------------------------------------*/
 
#ifndef limitedCubic_H
#define limitedCubic_H
 
#include "vector.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                      Class limitedCubicLimiter Declaration
\*---------------------------------------------------------------------------*/
 
template<class LimiterFunc>
class limitedCubicLimiter
:
    public LimiterFunc
{
    scalar k_;
    scalar twoByk_;
 
public:
 
    limitedCubicLimiter(Istream& is)
    :
        k_(readScalar(is))
    {
        if (k_ < 0 || k_ > 1)
        {
            FatalIOErrorInFunction(is)
                << "coefficient = " << k_
                << " should be >= 0 and <= 1"
                << exit(FatalIOError);
        }
 
        // Avoid the /0 when k_ = 0
        twoByk_ = 2.0/max(k_, SMALL);
    }
 
    scalar limiter
    (
        const scalar cdWeight,
        const scalar faceFlux,
        const typename LimiterFunc::phiType& phiP,
        const typename LimiterFunc::phiType& phiN,
        const typename LimiterFunc::gradPhiType& gradcP,
        const typename LimiterFunc::gradPhiType& gradcN,
        const vector& d
    ) const
    {
        scalar twor = twoByk_*LimiterFunc::r
        (
            faceFlux, phiP, phiN, gradcP, gradcN, d
        );
 
        scalar phiU;
 
        if (faceFlux > 0)
        {
            phiU = phiP;
        }
        else
        {
            phiU = phiN;
        }
 
        // Calculate the face value using cubic interpolation
        scalar phif =
            cdWeight*(phiP - 0.25*(d & gradcN))
          + (1 - cdWeight)*(phiN + 0.25*(d & gradcP));
 
        scalar phiCD = cdWeight*phiP + (1 - cdWeight)*phiN;
 
        // Calculate the effective limiter for the cubic interpolation
        scalar cubicLimiter = (phif - phiU)/stabilise(phiCD - phiU, SMALL);
 
        /*
        if (twor < 0.05)
        {
            cubicLimiter = twor;
        }
 
        return max(min(cubicLimiter, 2), 0);
        */
 
        // Limit the limiter to obey the TVD constraint
        return max(min(min(twor, cubicLimiter), 2), 0);
    }
};
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //