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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 QUICKLimiter 00027 00028 Description 00029 Class with limiter function which returns the limiter for the 00030 quadratic-upwind differencing scheme. Note that the weighting factors are 00031 not bounded between upwind and central-differencing, some downwind 00032 contribution is possible although the interpolate is limited to be between 00033 the upwind and downwind cell values. 00034 00035 Used in conjunction with the template class LimitedScheme. 00036 00037 SourceFiles 00038 QUICK.C 00039 00040 \*---------------------------------------------------------------------------*/ 00041 00042 #ifndef QUICK_H 00043 #define QUICK_H 00044 00045 #include "vector.H" 00046 00047 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00048 00049 namespace Foam 00050 { 00051 00052 /*---------------------------------------------------------------------------*\ 00053 Class QUICKWeight Declaration 00054 \*---------------------------------------------------------------------------*/ 00055 00056 template<class LimiterFunc> 00057 class QUICKLimiter 00058 : 00059 public LimiterFunc 00060 { 00061 00062 public: 00063 00064 QUICKLimiter(Istream&) 00065 {} 00066 00067 scalar limiter 00068 ( 00069 const scalar cdWeight, 00070 const scalar faceFlux, 00071 const typename LimiterFunc::phiType& phiP, 00072 const typename LimiterFunc::phiType& phiN, 00073 const typename LimiterFunc::gradPhiType& gradcP, 00074 const typename LimiterFunc::gradPhiType& gradcN, 00075 const vector& d 00076 ) const 00077 { 00078 scalar phif = 0.5*(cdWeight*phiP + (1 - cdWeight)*phiN); 00079 scalar phiU; 00080 00081 if (faceFlux > 0) 00082 { 00083 phif += 0.5*(phiP + (1 - cdWeight)*(d & gradcP)); 00084 phiU = phiP; 00085 } 00086 else 00087 { 00088 phif += 0.5*(phiN - cdWeight*(d & gradcN)); 00089 phiU = phiN; 00090 } 00091 00092 scalar phiCD = cdWeight*phiP + (1 - cdWeight)*phiN; 00093 00094 // Calculate the effective limiter for the linearUpwind interpolation 00095 scalar QLimiter = (phif - phiU)/stabilise(phiCD - phiU, SMALL); 00096 00097 // Limit the limiter between upwind and downwind 00098 return max(min(QLimiter, 2), 0); 00099 } 00100 }; 00101 00102 00103 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00104 00105 } // End namespace Foam 00106 00107 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00108 00109 #endif 00110 00111 // ************************************************************************* //