src/lagrangian/dieselSpray/spraySubModels/breakupModel/breakupModel/breakupModel.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 "error.H"
  28 #include "breakupModel.H"
  29
  30 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  31
  32 namespace Foam
  33 {
  34
  35 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  36
  37 defineTypeNameAndDebug(breakupModel, 0);
  38
  39 defineRunTimeSelectionTable(breakupModel, dictionary);
  40
  41 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  42
  43 // Construct from components
  44 breakupModel::breakupModel
  45 (
  46     const dictionary& dict,
  47     spray& sm
  48 )
  49 :
  50     dict_(dict),
  51     spray_(sm),
  52     rndGen_(sm.rndGen()),
  53     includeOscillation_(dict_.lookup("includeOscillation")),
  54     TABcoeffsDict_(dict.subDict("TABCoeffs")),
  55     y0_(0.0),
  56     yDot0_(0.0),
  57     TABComega_(0.0),
  58     TABCmu_(0.0),
  59     TABWeCrit_(0.0)
  60 {
  61     if (includeOscillation_)
  62     {
  63         y0_ = readScalar(TABcoeffsDict_.lookup("y0"));
  64         yDot0_ = readScalar(TABcoeffsDict_.lookup("yDot0"));
  65         TABComega_ = readScalar(TABcoeffsDict_.lookup("Comega"));
  66         TABCmu_ = readScalar(TABcoeffsDict_.lookup("Cmu"));
  67         TABWeCrit_ = readScalar(TABcoeffsDict_.lookup("WeCrit"));
  68     }
  69 }
  70
  71
  72 // * * * * * * * * * * * * * * * * Destructor    * * * * * * * * * * * * * * //
  73
  74 breakupModel::~breakupModel()
  75 {}
  76
  77 // * * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * //
  78
  79 void breakupModel::updateParcelProperties
  80 (
  81     parcel& p,
  82     const scalar deltaT,
  83     const vector& Ug,
  84     const liquidMixture& fuels
  85 ) const
  86 {
  87
  88     if(includeOscillation_)
  89     {
  90
  91         scalar T = p.T();
  92         scalar pc = spray_.p()[p.cell()];
  93         scalar r = 0.5 * p.d();
  94         scalar r2 = r*r;
  95         scalar r3 = r*r2;
  96
  97         scalar rho = fuels.rho(pc, T, p.X());
  98         scalar sigma = fuels.sigma(pc, T, p.X());
  99         scalar mu = fuels.mu(pc, T, p.X());
 100
 101         // inverse of characteristic viscous damping time
 102         scalar rtd = 0.5*TABCmu_*mu/(rho*r2);
 103
 104         // oscillation frequency (squared)
 105         scalar omega2 = TABComega_ * sigma /(rho*r3) - rtd*rtd;
 106
 107         if(omega2 > 0)
 108         {
 109
 110             scalar omega = sqrt(omega2);
 111             scalar rhog = spray_.rho()[p.cell()];
 112             scalar We = p.We(Ug, rhog, sigma);
 113             scalar Wetmp = We/TABWeCrit_;
 114
 115             scalar y1 = p.dev() - Wetmp;
 116             scalar y2 = p.ddev()/omega;
 117
 118             // update distortion parameters
 119             scalar c = cos(omega*deltaT);
 120             scalar s = sin(omega*deltaT);
 121             scalar e = exp(-rtd*deltaT);
 122             y2 = (p.ddev() + y1*rtd)/omega;
 123
 124             p.dev() = Wetmp + e*(y1*c + y2*s);
 125             if (p.dev() < 0)
 126             {
 127                 p.dev() = 0.0;
 128                 p.ddev() = 0.0;
 129             }
 130             else
 131             {
 132                 p.ddev() = (Wetmp-p.dev())*rtd + e*omega*(y2*c - y1*s);
 133             }
 134         }
 135         else
 136         {
 137             // reset droplet distortion parameters
 138             p.dev() = 0;
 139             p.ddev() = 0;
 140         }
 141
 142     }
 143
 144 }
 145
 146
 147 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 148
 149 } // End namespace Foam
 150
 151 // ************************************************************************* //