src/FDM/JSBSim/FGAerodynamics.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGAerodynamics.cpp
   4  Author:       Jon S. Berndt
   5  Date started: 09/13/00
   6  Purpose:      Encapsulates the aerodynamic forces (gear and collision)
   7
   8  ------------- Copyright (C) 2000  Jon S. Berndt (jsb@hal-pc.org) -------------
   9
  10  This program is free software; you can redistribute it and/or modify it under
  11  the terms of the GNU General Public License as published by the Free Software
  12  Foundation; either version 2 of the License, or (at your option) any later
  13  version.
  14
  15  This program is distributed in the hope that it will be useful, but WITHOUT
  16  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  details.
  19
  20  You should have received a copy of the GNU General Public License along with
  21  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  22  Place - Suite 330, Boston, MA  02111-1307, USA.
  23
  24  Further information about the GNU General Public License can also be found on
  25  the world wide web at http://www.gnu.org.
  26
  27 FUNCTIONAL DESCRIPTION
  28 --------------------------------------------------------------------------------
  29
  30 HISTORY
  31 --------------------------------------------------------------------------------
  32 09/13/00   JSB   Created
  33 04/22/01   JSB   Moved code into here from FGAircraft
  34
  35 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  36 INCLUDES
  37 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  38
  39 #include "FGAerodynamics.h"
  40 #include "FGFactorGroup.h"
  41 #include "FGCoefficient.h"
  42
  43 static const char *IdSrc = "$Id$";
  44 static const char *IdHdr = ID_AERODYNAMICS;
  45
  46 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  47 CLASS IMPLEMENTATION
  48 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  49
  50
  51 FGAerodynamics::FGAerodynamics(FGFDMExec* FDMExec) : FGModel(FDMExec),
  52     vMoments(3),
  53     vForces(3),
  54     vFs(3),
  55     vLastFs(3),
  56     vDXYZcg(3)
  57 {
  58   Name = "FGAerodynamics";
  59
  60   AxisIdx["DRAG"]  = 0;
  61   AxisIdx["SIDE"]  = 1;
  62   AxisIdx["LIFT"]  = 2;
  63   AxisIdx["ROLL"]  = 3;
  64   AxisIdx["PITCH"] = 4;
  65   AxisIdx["YAW"]   = 5;
  66
  67   Coeff = new CoeffArray[6];
  68
  69   if (debug_lvl & 2) cout << "Instantiated: FGAerodynamics" << endl;
  70 }
  71
  72 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  73
  74 FGAerodynamics::~FGAerodynamics()
  75 {
  76   unsigned int i,j;
  77   for (i=0; i<6; i++) {
  78     for (j=0; j<Coeff[i].size(); j++) {
  79       delete Coeff[i][j];
  80     }
  81   }
  82   delete[] Coeff;
  83
  84   if (debug_lvl & 2) cout << "Destroyed:    FGAerodynamics" << endl;
  85 }
  86
  87 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  88
  89 bool FGAerodynamics::Run(void)
  90 {
  91   unsigned int axis_ctr,ctr;
  92
  93   if (!FGModel::Run()) {
  94
  95     vLastFs = vFs;
  96     vFs.InitMatrix();
  97
  98     for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
  99       for (ctr=0; ctr < Coeff[axis_ctr].size(); ctr++) {
 100         vFs(axis_ctr+1) += Coeff[axis_ctr][ctr]->TotalValue();
 101       }
 102     }
 103
 104     vForces = State->GetTs2b()*vFs;
 105
 106     vDXYZcg(eX) = -(Aircraft->GetXYZrp(eX)
 107                       - MassBalance->GetXYZcg(eX))*inchtoft;
 108     vDXYZcg(eY) =  (Aircraft->GetXYZrp(eY)
 109                       - MassBalance->GetXYZcg(eY))*inchtoft;
 110     vDXYZcg(eZ) = -(Aircraft->GetXYZrp(eZ)
 111                       - MassBalance->GetXYZcg(eZ))*inchtoft;
 112
 113     vMoments = vDXYZcg*vForces; // M = r X F
 114
 115     for (axis_ctr = 0; axis_ctr < 3; axis_ctr++) {
 116       for (ctr = 0; ctr < Coeff[axis_ctr+3].size(); ctr++) {
 117         vMoments(axis_ctr+1) += Coeff[axis_ctr+3][ctr]->TotalValue();
 118       }
 119     }
 120     return false;
 121   } else {
 122     return true;
 123   }
 124 }
 125
 126 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 127
 128 bool FGAerodynamics::Load(FGConfigFile* AC_cfg)
 129 {
 130   string token, axis;
 131
 132   AC_cfg->GetNextConfigLine();
 133
 134   while ((token = AC_cfg->GetValue()) != string("/AERODYNAMICS")) {
 135     if (token == "AXIS") {
 136       CoeffArray ca;
 137       axis = AC_cfg->GetValue("NAME");
 138       AC_cfg->GetNextConfigLine();
 139       while ((token = AC_cfg->GetValue()) != string("/AXIS")) {
 140         if( token == "COEFFICIENT" ) {
 141           ca.push_back( new FGCoefficient(FDMExec) );
 142           ca.back()->Load(AC_cfg);
 143         } else if ( token == "GROUP" ) {
 144           ca.push_back( new FGFactorGroup(FDMExec) );
 145           ca.back()->Load(AC_cfg);
 146         }
 147       }
 148       Coeff[AxisIdx[axis]] = ca;
 149       AC_cfg->GetNextConfigLine();
 150     }
 151   }
 152
 153   return true;
 154 }
 155
 156 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 157
 158 string FGAerodynamics::GetCoefficientStrings(void)
 159 {
 160   string CoeffStrings = "";
 161   bool firstime = true;
 162   unsigned int axis, sd;
 163
 164   for (axis = 0; axis < 6; axis++) {
 165     for (sd = 0; sd < Coeff[axis].size(); sd++) {
 166       if (firstime) {
 167         firstime = false;
 168       } else {
 169         CoeffStrings += ", ";
 170       }
 171       CoeffStrings += Coeff[axis][sd]->GetCoefficientStrings();
 172     }
 173   }
 174   return CoeffStrings;
 175 }
 176
 177 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 178
 179 string FGAerodynamics::GetCoefficientValues(void)
 180 {
 181   string SDValues = "";
 182   char buffer[10];
 183   bool firstime = true;
 184
 185   for (unsigned int axis = 0; axis < 6; axis++) {
 186     for (unsigned int sd = 0; sd < Coeff[axis].size(); sd++) {
 187       if (firstime) {
 188         firstime = false;
 189       } else {
 190         SDValues += ", ";
 191       }
 192       SDValues += Coeff[axis][sd]->GetCoefficientValues();
 193     }
 194   }
 195
 196   return SDValues;
 197 }
 198
 199 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 200
 201 double FGAerodynamics::GetNlf(void)
 202 {
 203   if (fabs(Position->GetGamma()) < 1.57) {
 204     return (vFs(eZ)/(MassBalance->GetWeight()*cos(Position->GetGamma())));
 205   } else {
 206     return 0.0;
 207   }
 208 }
 209
 210 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 211
 212 double FGAerodynamics::GetLoD(void)
 213 {
 214   double LoD;
 215
 216   if (vFs(1) != 0.00) return vFs(3)/vFs(1);
 217   else                return 0.00;
 218 }
 219
 220 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 221
 222 void FGAerodynamics::Debug(void)
 223 {
 224     //TODO: Add your source code here
 225 }
 226