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limitedCubic.H

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00001 /*---------------------------------------------------------------------------*\
00002   =========                 |
00003   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
00004    \\    /   O peration     |
00005     \\  /    A nd           | Copyright (C) 1991-2005 OpenCFD Ltd.
00006      \\/     M anipulation  |
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00008 License
00009     This file is part of OpenFOAM.
00010 
00011     OpenFOAM is free software; you can redistribute it and/or modify it
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00015 
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00019     for more details.
00020 
00021     You should have received a copy of the GNU General Public License
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00023     Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
00024 
00025 Class
00026     limitedCubicLimiter
00027 
00028 Description
00029     Class with limiter function which returns the limiter for the
00030     TVD limited centred-cubic differencing scheme based on r obtained from
00031     the LimiterFunc class.
00032 
00033     Used in conjunction with the template class LimitedScheme.
00034 
00035 SourceFiles
00036     limitedCubic.C
00037 
00038 \*---------------------------------------------------------------------------*/
00039 
00040 #ifndef limitedCubic_H
00041 #define limitedCubic_H
00042 
00043 #include "vector.H"
00044 
00045 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
00046 
00047 namespace Foam
00048 {
00049 
00050 /*---------------------------------------------------------------------------*\
00051                            Class limitedCubicWeight Declaration
00052 \*---------------------------------------------------------------------------*/
00053 
00054 template<class LimiterFunc>
00055 class limitedCubicLimiter
00056 :
00057     public LimiterFunc
00058 {
00059     scalar k_;
00060     scalar twoByk_;
00061 
00062 public:
00063 
00064     limitedCubicLimiter(Istream& is)
00065     :
00066         k_(readScalar(is))
00067     {
00068         if (k_ < 0 || k_ > 1)
00069         {
00070             FatalIOErrorIn("GammaWeight(Istream& is)", is)
00071                 << "coefficient = " << k_
00072                 << " should be >= 0 and <= 1"
00073                 << exit(FatalIOError);
00074         }
00075 
00076         // Avoid the /0 when k_ = 0
00077         twoByk_ = 2.0/max(k_, SMALL);
00078     }
00079 
00080     scalar limiter
00081     (
00082         const scalar cdWeight,
00083         const scalar faceFlux,
00084         const typename LimiterFunc::phiType& phiP,
00085         const typename LimiterFunc::phiType& phiN,
00086         const typename LimiterFunc::gradPhiType& gradcP,
00087         const typename LimiterFunc::gradPhiType& gradcN,
00088         const vector& d
00089     ) const
00090     {
00091         scalar twor = twoByk_*LimiterFunc::r
00092         (
00093             cdWeight, faceFlux, phiP, phiN, gradcP, gradcN, d
00094         );
00095 
00096         scalar phiU;
00097 
00098         if (faceFlux > 0)
00099         {
00100             phiU = phiP;
00101         }
00102         else
00103         {
00104             phiU = phiN;
00105         }
00106 
00107         // Calculate the face value using cubic interpolation
00108         scalar phif = 
00109             cdWeight*(phiP - 0.25*(d & gradcN))
00110           + (1 - cdWeight)*(phiN + 0.25*(d & gradcP));
00111 
00112         scalar phiCD = cdWeight*phiP + (1 - cdWeight)*phiN;
00113 
00114         // Calculate the effective limiter for the cubic interpolation
00115         scalar cubicLimiter = (phif - phiU)/stabilise(phiCD - phiU, SMALL);
00116 
00117         /*
00118         if (twor < 0.05)
00119         {
00120             cubicLimiter = twor;
00121         }
00122 
00123         return max(min(cubicLimiter, 2), 0);
00124         */
00125 
00126         // Limit the limiter to obey the TVD constraint
00127         return max(min(min(twor, cubicLimiter), 2), 0);
00128     }
00129 };
00130 
00131 
00132 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
00133 
00134 } // End namespace Foam
00135 
00136 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
00137 
00138 #endif
00139 
00140 // ************************************************************************* //
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