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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 linearUpwind 00027 00028 Description 00029 Class with operator() which returns the weighting factors for the 00030 linear-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 NVDscheme although this scheme 00036 is not NVD. 00037 00038 SourceFiles 00039 linearUpwindMake.C 00040 00041 \*---------------------------------------------------------------------------*/ 00042 00043 #ifndef linearUpwind_H 00044 #define linearUpwind_H 00045 00046 #include "scalar.H" 00047 #include "vector.H" 00048 00049 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00050 00051 namespace Foam 00052 { 00053 00054 /*---------------------------------------------------------------------------*\ 00055 Class linearUpwindWeight Declaration 00056 \*---------------------------------------------------------------------------*/ 00057 00058 class linearUpwindWeight 00059 { 00060 00061 public: 00062 00063 linearUpwindWeight(Istream&) 00064 {} 00065 00066 scalar weight 00067 ( 00068 scalar cdWeight, 00069 scalar faceFlux, 00070 scalar phiP, 00071 scalar phiN, 00072 const vector& gradcP, 00073 const vector& gradcN, 00074 const vector& d 00075 ) const 00076 { 00077 scalar phif; 00078 if (faceFlux > 0) 00079 { 00080 phif = phiP + (1 - cdWeight)*(d & gradcP); 00081 } 00082 else 00083 { 00084 phif = phiN - cdWeight*(d & gradcN); 00085 } 00086 00087 // Limit the estimated face value between the upwind and downwind cell 00088 // values 00089 phif = min(phif, max(phiN, phiP)); 00090 phif = max(phif, min(phiN, phiP)); 00091 00092 return (phif - phiN)/stabilise(phiP - phiN, SMALL); 00093 } 00094 }; 00095 00096 00097 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00098 00099 } // End namespace Foam 00100 00101 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00102 00103 #endif 00104 00105 // ************************************************************************* //