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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 | 00007 ------------------------------------------------------------------------------- 00008 License 00009 This file is part of OpenFOAM. 00010 00011 OpenFOAM is free software; you can redistribute it and/or modify it 00012 under the terms of the GNU General Public License as published by the 00013 Free Software Foundation; either version 2 of the License, or (at your 00014 option) any later version. 00015 00016 OpenFOAM is distributed in the hope that it will be useful, but WITHOUT 00017 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00018 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 00019 for more details. 00020 00021 You should have received a copy of the GNU General Public License 00022 along with OpenFOAM; if not, write to the Free Software Foundation, 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 // ************************************************************************* //