src/postProcessing/functionObjects/forces/pointPatchFields/derived/sixDoFRigidBodyMotion/sixDoFRigidBodyMotionRestraint/sphericalAngularSpring/sphericalAngularSpring.C

   1 /*---------------------------------------------------------------------------*\
   2   =========                 |
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   5     \\  /    A nd           | Copyright (C) 1991-2009 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 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 "sphericalAngularSpring.H"
  28 #include "addToRunTimeSelectionTable.H"
  29 #include "sixDoFRigidBodyMotion.H"
  30
  31 // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
  32
  33 namespace Foam
  34 {
  35 namespace sixDoFRigidBodyMotionRestraints
  36 {
  37     defineTypeNameAndDebug(sphericalAngularSpring, 0);
  38     addToRunTimeSelectionTable
  39     (
  40         sixDoFRigidBodyMotionRestraint,
  41         sphericalAngularSpring,
  42         dictionary
  43     );
  44 };
  45 };
  46
  47
  48 // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
  49
  50 Foam::sixDoFRigidBodyMotionRestraints::sphericalAngularSpring::
  51 sphericalAngularSpring
  52 (
  53     const dictionary& sDoFRBMRDict
  54 )
  55 :
  56     sixDoFRigidBodyMotionRestraint(sDoFRBMRDict),
  57     refQ_(),
  58     stiffness_(),
  59     damping_()
  60 {
  61     read(sDoFRBMRDict);
  62 }
  63
  64
  65 // * * * * * * * * * * * * * * * * Destructors * * * * * * * * * * * * * * * //
  66
  67 Foam::sixDoFRigidBodyMotionRestraints::sphericalAngularSpring::
  68 ~sphericalAngularSpring()
  69 {}
  70
  71
  72 // * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * * //
  73
  74 void
  75 Foam::sixDoFRigidBodyMotionRestraints::sphericalAngularSpring::restrain
  76 (
  77     const sixDoFRigidBodyMotion& motion,
  78     vector& restraintPosition,
  79     vector& restraintForce,
  80     vector& restraintMoment
  81 ) const
  82 {
  83     restraintMoment = vector::zero;
  84
  85     for (direction cmpt=0; cmpt<vector::nComponents; cmpt++)
  86     {
  87         vector axis = vector::zero;
  88
  89         axis[cmpt] = 1;
  90
  91         vector refDir = vector::zero;
  92
  93         refDir[(cmpt + 1) % 3] = 1;
  94
  95         vector newDir = motion.orientation() & refDir;
  96
  97         axis = (refQ_ & axis);
  98
  99         refDir = (refQ_ & refDir);
 100
 101         newDir -= (axis & newDir)*axis;
 102
 103         restraintMoment += -stiffness_*(refDir ^ newDir);
 104     }
 105
 106     restraintMoment += -damping_*motion.omega();
 107
 108     restraintForce = vector::zero;
 109
 110     // Not needed to be altered as restraintForce is zero, but set to
 111     // centreOfMass to be sure of no spurious moment
 112     restraintPosition = motion.centreOfMass();
 113
 114     if (motion.report())
 115     {
 116         Info<< " force " << restraintForce
 117             << " moment " << restraintMoment
 118             << endl;
 119     }
 120 }
 121
 122
 123 bool Foam::sixDoFRigidBodyMotionRestraints::sphericalAngularSpring::read
 124 (
 125     const dictionary& sDoFRBMRDict
 126 )
 127 {
 128     sixDoFRigidBodyMotionRestraint::read(sDoFRBMRDict);
 129
 130     refQ_ = sDoFRBMRCoeffs_.lookupOrDefault<tensor>("referenceOrientation", I);
 131
 132     if (mag(mag(refQ_) - sqrt(3.0)) > 1e-9)
 133     {
 134         FatalErrorIn
 135         (
 136             "Foam::sixDoFRigidBodyMotionRestraints::sphericalAngularSpring::"
 137             "read"
 138             "("
 139                 "const dictionary& sDoFRBMRDict"
 140             ")"
 141         )
 142             << "referenceOrientation " << refQ_ << " is not a rotation tensor. "
 143             << "mag(referenceOrientation) - sqrt(3) = "
 144             << mag(refQ_) - sqrt(3.0) << nl
 145             << exit(FatalError);
 146     }
 147
 148     sDoFRBMRCoeffs_.lookup("stiffness") >> stiffness_;
 149
 150     sDoFRBMRCoeffs_.lookup("damping") >> damping_;
 151
 152     return true;
 153 }
 154
 155
 156 void Foam::sixDoFRigidBodyMotionRestraints::sphericalAngularSpring::write
 157 (
 158     Ostream& os
 159 ) const
 160 {
 161     os.writeKeyword("referenceOrientation")
 162         << refQ_ << token::END_STATEMENT << nl;
 163
 164     os.writeKeyword("stiffness") << stiffness_ << token::END_STATEMENT << nl;
 165
 166     os.writeKeyword("damping") << damping_ << token::END_STATEMENT << nl;
 167 }
 168
 169
 170 // ************************************************************************* //