00001 /*---------------------------------------------------------------------------* \ 00002 ========= | 00003 \\ / F ield | OpenFOAM: The Open Source CFD Toolbox 00004 \\ / O peration | 00005 \\ / A nd | Copyright (C) 1991-2010 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 00013 the Free Software Foundation, either version 3 of the License, or 00014 (at your 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, see <http://www.gnu.org/licenses/>. 00023 00024 Application 00025 Q 00026 00027 Description 00028 Calculates and writes the second invariant of the velocity gradient tensor. 00029 00030 The -noWrite option just outputs the max/min values without writing 00031 the field. 00032 00033 Usage 00034 00035 - Q [OPTIONS] 00036 00037 @param -noWrite \n 00038 Suppress output to files. 00039 00040 @param -dict <dictionary name>\n 00041 Use named dictionary instead of system/controlDict. 00042 00043 @param -noZero \n 00044 Ignore timestep 0. 00045 00046 @param -constant \n 00047 Include the constant directory. 00048 00049 @param -time <time>\n 00050 Apply only to specific time. 00051 00052 @param -latestTime \n 00053 Only apply to latest time step. 00054 00055 @param -case <dir>\n 00056 Case directory. 00057 00058 @param -parallel \n 00059 Run in parallel. 00060 00061 @param -help \n 00062 Display help message. 00063 00064 @param -doc \n 00065 Display Doxygen API documentation page for this application. 00066 00067 @param -srcDoc \n 00068 Display Doxygen source documentation page for this application. 00069 00070 \*---------------------------------------------------------------------------*/ 00071 00072 #include <postCalc/calc.H> 00073 #include <finiteVolume/fvc.H> 00074 00075 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00076 00077 void Foam::calc(const argList& args, const Time& runTime, const fvMesh& mesh) 00078 { 00079 bool writeResults = !args.optionFound("noWrite"); 00080 00081 IOobject Uheader 00082 ( 00083 "U", 00084 runTime.timeName(), 00085 mesh, 00086 IOobject::MUST_READ 00087 ); 00088 00089 if (Uheader.headerOk()) 00090 { 00091 Info<< " Reading U" << endl; 00092 volVectorField U(Uheader, mesh); 00093 volTensorField gradU = fvc::grad(U); 00094 00095 volScalarField Q 00096 ( 00097 IOobject 00098 ( 00099 "Q", 00100 runTime.timeName(), 00101 mesh, 00102 IOobject::NO_READ, 00103 IOobject::NO_WRITE 00104 ), 00105 0.5*(sqr(tr(gradU)) - tr(((gradU)&(gradU)))) 00106 ); 00107 00108 /* 00109 // This is a second way of calculating Q, that delivers results 00110 // very close, but not identical to the first approach. 00111 00112 volSymmTensorField S = symm(gradU); // symmetric part of tensor 00113 volTensorField W = skew(gradU); // anti-symmetric part 00114 00115 volScalarField SS = S&&S; 00116 volScalarField WW = W&&W; 00117 00118 volScalarField Q 00119 ( 00120 IOobject 00121 ( 00122 "Q", 00123 runTime.timeName(), 00124 mesh, 00125 IOobject::NO_READ, 00126 IOobject::NO_WRITE 00127 ), 00128 0.5*(WW - SS) 00129 ); 00130 */ 00131 00132 Info<< "mag(Q) max/min : " 00133 << max(Q).value() << " " 00134 << min(Q).value() << endl; 00135 00136 if (writeResults) 00137 { 00138 Q.write(); 00139 } 00140 } 00141 else 00142 { 00143 Info<< " No U" << endl; 00144 } 00145 00146 Info<< "\nEnd\n" << endl; 00147 } 00148 00149 00150 // ************************ vim: set sw=4 sts=4 et: ************************ //