src/lagrangian/dieselSpray/spraySubModels/injectorModel/pressureSwirl/pressureSwirlInjector.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
   3   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   4    \\    /   O peration     |
   5     \\  /    A nd           | Copyright (C) 2004-2010 OpenCFD Ltd.
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   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
  13     the Free Software Foundation, either version 3 of the License, or
  14     (at your 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, see <http://www.gnu.org/licenses/>.
  23
  24 \*---------------------------------------------------------------------------*/
  25
  26 #include "pressureSwirlInjector.H"
  27 #include "addToRunTimeSelectionTable.H"
  28 #include "mathematicalConstants.H"
  29
  30 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  31
  32 namespace Foam
  33 {
  34     defineTypeNameAndDebug(pressureSwirlInjector, 0);
  35
  36     addToRunTimeSelectionTable
  37     (
  38         injectorModel,
  39         pressureSwirlInjector,
  40         dictionary
  41     );
  42 }
  43
  44
  45 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  46
  47 Foam::pressureSwirlInjector::pressureSwirlInjector
  48 (
  49     const dictionary& dict,
  50     spray& sm
  51 )
  52 :
  53     injectorModel(dict, sm),
  54     pressureSwirlInjectorDict_(dict.subDict(typeName + "Coeffs")),
  55
  56     coneAngle_(pressureSwirlInjectorDict_.lookup("ConeAngle")),
  57     coneInterval_(pressureSwirlInjectorDict_.lookup("ConeInterval")),
  58     maxKv_(pressureSwirlInjectorDict_.lookup("maxKv")),
  59
  60     angle_(0.0)
  61 {
  62
  63     if (sm.injectors().size() != coneAngle_.size())
  64     {
  65         FatalErrorIn
  66         (
  67             "pressureSwirlInjector::pressureSwirlInjector"
  68             "(const dictionary& dict, spray& sm)"
  69         )   << "Wrong number of entries in innerAngle" << nl
  70             << abort(FatalError);
  71     }
  72
  73     scalar referencePressure = sm.p().average().value();
  74
  75     // correct velocityProfile
  76     forAll(sm.injectors(), i)
  77     {
  78         sm.injectors()[i].properties()->correctProfiles
  79         (
  80             sm.fuels(),
  81             referencePressure
  82         );
  83     }
  84 }
  85
  86
  87 // * * * * * * * * * * * * * * * * Destructor  * * * * * * * * * * * * * * * //
  88
  89 Foam::pressureSwirlInjector::~pressureSwirlInjector()
  90 {}
  91
  92
  93 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
  94
  95 Foam::scalar Foam::pressureSwirlInjector::d0
  96 (
  97     const label n,
  98     const scalar t
  99 ) const
 100 {
 101     const injectorType& it = injectors_[n].properties();
 102
 103     scalar c = rndGen_.sample01<scalar>();
 104     angle_ = coneAngle_[n] + 2.0*coneInterval_[n]*(0.5 - c);
 105
 106     angle_ *= constant::mathematical::pi/360.0;
 107
 108     scalar injectedMassFlow = it.massFlowRate(t);
 109
 110     scalar cosAngle = cos(angle_);
 111
 112     scalar rhoFuel = sm_.fuels().rho(sm_.ambientPressure(), it.T(t), it.X());
 113     scalar injectorDiameter = it.d();
 114
 115     scalar deltaPressure = deltaPressureInj(t,n);
 116     scalar kV = kv(n, injectedMassFlow, deltaPressure);
 117     scalar v = kV*sqrt(2.0*deltaPressure/rhoFuel);
 118
 119     u_ = v*cosAngle;
 120
 121     scalar A = injectedMassFlow/(constant::mathematical::pi*rhoFuel*u_);
 122
 123     return (injectorDiameter-sqrt(pow(injectorDiameter,2)-4.0*A))/2.0;
 124 }
 125
 126
 127 Foam::vector Foam::pressureSwirlInjector::direction
 128 (
 129     const label n,
 130     const label hole,
 131     const scalar time,
 132     const scalar d
 133 ) const
 134 {
 135     scalar alpha = sin(angle_);
 136     scalar dcorr = cos(angle_);
 137     scalar beta = constant::mathematical::twoPi*rndGen_.sample01<scalar>();
 138
 139     // randomly distributed vector normal to the injection vector
 140     vector normal = vector::zero;
 141
 142     if (sm_.twoD())
 143     {
 144         scalar reduce = 0.01;
 145         // correct beta if this is a 2D run
 146         // map it onto the 'angleOfWedge'
 147
 148         beta *=
 149             (1.0 - 2.0*reduce)
 150            *sm_.angleOfWedge()
 151           /(constant::mathematical::twoPi);
 152         beta += reduce*sm_.angleOfWedge();
 153         normal =
 154             alpha
 155            *(
 156                 sm_.axisOfWedge()*cos(beta)
 157               + sm_.axisOfWedgeNormal()*sin(beta)
 158             );
 159     }
 160     else
 161     {
 162         normal =
 163             alpha
 164            *(
 165                 injectors_[n].properties()->tan1(hole)*cos(beta)
 166               + injectors_[n].properties()->tan2(hole)*sin(beta)
 167             );
 168     }
 169
 170     // set the direction of injection by adding the normal vector
 171     vector dir =
 172         dcorr*injectors_[n].properties()->direction(hole, time) + normal;
 173     dir /= mag(dir);
 174
 175     return dir;
 176 }
 177
 178
 179 Foam::scalar Foam::pressureSwirlInjector::velocity
 180 (
 181     const label i,
 182     const scalar time
 183 ) const
 184 {
 185     return u_*sqrt(1.0 + pow(tan(angle_),2.0));
 186 }
 187
 188
 189 Foam::scalar Foam::pressureSwirlInjector::averageVelocity(const label i) const
 190 {
 191     const injectorType& it = sm_.injectors()[i].properties();
 192
 193     scalar dt = it.teoi() - it.tsoi();
 194
 195     scalar injectedMassFlow = it.mass()/(it.teoi()-it.tsoi());
 196
 197     scalar injectionPressure = averagePressure(i);
 198
 199     scalar Tav = it.integrateTable(it.T())/dt;
 200     scalar rhoFuel = sm_.fuels().rho(sm_.ambientPressure(), Tav, it.X());
 201
 202     scalar kV = kv(i, injectedMassFlow, injectionPressure);
 203
 204     return  kV*sqrt(2.0*(injectionPressure-sm_.ambientPressure())/rhoFuel);
 205 }
 206
 207
 208 Foam::scalar Foam::pressureSwirlInjector::kv
 209 (
 210     const label inj,
 211     const scalar massFlow,
 212     const scalar dPressure
 213 ) const
 214 {
 215     const injectorType& it = injectors_[inj].properties();
 216
 217     scalar coneAngle = coneAngle_[inj];
 218
 219     coneAngle *= constant::mathematical::pi/360.0;
 220
 221     scalar cosAngle = cos(coneAngle);
 222     scalar Tav = it.integrateTable(it.T())/(it.teoi()-it.tsoi());
 223
 224     scalar rhoFuel = sm_.fuels().rho(sm_.ambientPressure(), Tav, it.X());
 225     scalar injectorDiameter = it.d();
 226
 227     scalar kv = max
 228     (
 229         maxKv_[inj],
 230         4.0*massFlow
 231        *sqrt(rhoFuel/2.0/dPressure)
 232        /(constant::mathematical::pi*sqr(injectorDiameter)*rhoFuel*cosAngle)
 233     );
 234
 235     return min(1.0, kv);
 236 }
 237
 238
 239 Foam::scalar Foam::pressureSwirlInjector::deltaPressureInj
 240 (
 241     const scalar time,
 242     const label inj
 243 ) const
 244 {
 245     return
 246         injectors_[inj].properties()->injectionPressure(time)
 247       - sm_.ambientPressure();
 248 }
 249
 250
 251 Foam::scalar Foam::pressureSwirlInjector::averagePressure(const label inj) const
 252 {
 253
 254     const injectorType& it = sm_.injectors()[inj].properties();
 255
 256     scalar dt = it.teoi() - it.tsoi();
 257     return it.integrateTable(it.injectionPressureProfile())/dt;
 258 }
 259
 260
 261 // ************************************************************************* //