src/postProcessing/functionObjects/forces/forceCoeffs/forceCoeffs.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
   3   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   4    \\    /   O peration     |
   5     \\  /    A nd           | Copyright (C) 1991-2009 OpenCFD Ltd.
   6      \\/     M anipulation  |
   7 -------------------------------------------------------------------------------
   8 License
   9     This file is part of OpenFOAM.
  10
  11     OpenFOAM is free software; you can redistribute it and/or modify it
  12     under the terms of the GNU General Public License as published by the
  13     Free Software Foundation; either version 2 of the License, or (at your
  14     option) any later version.
  15
  16     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
  17     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19     for more details.
  20
  21     You should have received a copy of the GNU General Public License
  22     along with OpenFOAM; if not, write to the Free Software Foundation,
  23     Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  24
  25 \*---------------------------------------------------------------------------*/
  26
  27 #include "forceCoeffs.H"
  28 #include "dictionary.H"
  29 #include "Time.H"
  30 #include "Pstream.H"
  31
  32 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  33
  34 namespace Foam
  35 {
  36     defineTypeNameAndDebug(forceCoeffs, 0);
  37 }
  38
  39
  40 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  41
  42 Foam::forceCoeffs::forceCoeffs
  43 (
  44     const word& name,
  45     const objectRegistry& obr,
  46     const dictionary& dict,
  47     const bool loadFromFiles
  48 )
  49 :
  50     forces(name, obr, dict, loadFromFiles),
  51     liftDir_(vector::zero),
  52     dragDir_(vector::zero),
  53     pitchAxis_(vector::zero),
  54     magUInf_(0.0),
  55     lRef_(0.0),
  56     Aref_(0.0)
  57 {
  58     read(dict);
  59 }
  60
  61
  62 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
  63
  64 Foam::forceCoeffs::~forceCoeffs()
  65 {}
  66
  67
  68 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
  69
  70 void Foam::forceCoeffs::read(const dictionary& dict)
  71 {
  72     if (active_)
  73     {
  74         forces::read(dict);
  75
  76         // Directions for lift and drag forces, and pitch moment
  77         dict.lookup("liftDir") >> liftDir_;
  78         dict.lookup("dragDir") >> dragDir_;
  79         dict.lookup("pitchAxis") >> pitchAxis_;
  80
  81         // Free stream velocity magnitude
  82         dict.lookup("magUInf") >> magUInf_;
  83
  84         // Reference length and area scales
  85         dict.lookup("lRef") >> lRef_;
  86         dict.lookup("Aref") >> Aref_;
  87     }
  88 }
  89
  90
  91 void Foam::forceCoeffs::writeFileHeader()
  92 {
  93     if (forcesFilePtr_.valid())
  94     {
  95         forcesFilePtr_()
  96             << "# Time" << tab << "Cd" << tab << "Cl" << tab << "Cm" << endl;
  97     }
  98 }
  99
 100
 101 void Foam::forceCoeffs::execute()
 102 {
 103     // Do nothing - only valid on write
 104 }
 105
 106
 107 void Foam::forceCoeffs::end()
 108 {
 109     // Do nothing - only valid on write
 110 }
 111
 112
 113 void Foam::forceCoeffs::write()
 114 {
 115     if (active_)
 116     {
 117         // Create the forces file if not already created
 118         makeFile();
 119
 120         forcesMoments fm = forces::calcForcesMoment();
 121
 122         scalar pDyn = 0.5*rhoRef_*magUInf_*magUInf_;
 123
 124         vector totForce = fm.first().first() + fm.first().second();
 125         vector totMoment = fm.second().first() + fm.second().second();
 126
 127         scalar liftForce = totForce & liftDir_;
 128         scalar dragForce = totForce & dragDir_;
 129         scalar pitchMoment = totMoment & pitchAxis_;
 130
 131         scalar Cl = liftForce/(Aref_*pDyn);
 132         scalar Cd = dragForce/(Aref_*pDyn);
 133         scalar Cm = pitchMoment/(Aref_*lRef_*pDyn);
 134
 135         if (Pstream::master())
 136         {
 137             forcesFilePtr_()
 138                 << obr_.time().value() << tab
 139                 << Cd << tab << Cl << tab << Cm << endl;
 140
 141             if (log_)
 142             {
 143                 Info<< "forceCoeffs output:" << nl
 144                     << "    Cd = " << Cd << nl
 145                     << "    Cl = " << Cl << nl
 146                     << "    Cm = " << Cm << nl
 147                     << endl;
 148             }
 149         }
 150     }
 151 }
 152
 153
 154 // ************************************************************************* //