src/FDM/JSBSim/models/propulsion/FGEngine.cpp

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Module:       FGEngine.cpp
   4  Author:       Jon Berndt
   5  Date started: 01/21/99
   6  Called by:    FGAircraft
   7
   8  ------------- Copyright (C) 1999  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 Lesser 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 Lesser General Public License for more details.
  18
  19  You should have received a copy of the GNU Lesser General Public License along with
  20  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  21  Place - Suite 330, Boston, MA  02111-1307, USA.
  22
  23  Further information about the GNU Lesser General Public License can also be found on
  24  the world wide web at http://www.gnu.org.
  25
  26 FUNCTIONAL DESCRIPTION
  27 --------------------------------------------------------------------------------
  28 See header file.
  29
  30 HISTORY
  31 --------------------------------------------------------------------------------
  32 01/21/99   JSB   Created
  33 09/03/99   JSB   Changed Rocket thrust equation to correct -= Thrust instead of
  34                  += Thrust (thanks to Tony Peden)
  35
  36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  37 INCLUDES
  38 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  39
  40 #ifdef FGFS
  41 #  include <simgear/compiler.h>
  42 #  ifdef SG_HAVE_STD_INCLUDES
  43 #    include <fstream>
  44 #  else
  45 #    include <fstream.h>
  46 #  endif
  47 #else
  48 #  if defined(sgi) && !defined(__GNUC__) && (_COMPILER_VERSION < 740)
  49 #    include <fstream.h>
  50 #  else
  51 #    include <fstream>
  52 #  endif
  53 #endif
  54
  55 #include "FGEngine.h"
  56 #include "FGTank.h"
  57 #include "FGPropeller.h"
  58 #include "FGNozzle.h"
  59 #include <input_output/FGXMLParse.h>
  60 #include <math/FGColumnVector3.h>
  61
  62 namespace JSBSim {
  63
  64 static const char *IdSrc = "$Id$";
  65 static const char *IdHdr = ID_ENGINE;
  66
  67 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  68 CLASS IMPLEMENTATION
  69 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  70
  71 FGEngine::FGEngine(FGFDMExec* exec, Element* engine_element, int engine_number)
  72                       : EngineNumber(engine_number)
  73 {
  74   Element* local_element;
  75   FGColumnVector3 location, orientation;
  76
  77   Name = "";
  78   Type = etUnknown;
  79   X = Y = Z = 0.0;
  80   EnginePitch = EngineYaw = 0.0;
  81   SLFuelFlowMax = SLOxiFlowMax = 0.0;
  82   MaxThrottle = 1.0;
  83   MinThrottle = 0.0;
  84   Thrust = 0.0;
  85   Throttle = 0.0;
  86   Mixture = 1.0;
  87   Starter = false;
  88   FuelNeed = OxidizerNeed = 0.0;
  89   Starved = Running = Cranking = false;
  90   PctPower = 0.0;
  91   TrimMode = false;
  92   FuelFlow_gph = 0.0;
  93   FuelFlow_pph = 0.0;
  94   FuelFreeze = false;
  95
  96   FDMExec = exec;
  97   State = FDMExec->GetState();
  98   Atmosphere = FDMExec->GetAtmosphere();
  99   FCS = FDMExec->GetFCS();
 100   Propulsion = FDMExec->GetPropulsion();
 101   Aircraft = FDMExec->GetAircraft();
 102   Propagate = FDMExec->GetPropagate();
 103   Auxiliary = FDMExec->GetAuxiliary();
 104
 105   PropertyManager = FDMExec->GetPropertyManager();
 106
 107   Name = engine_element->GetAttributeValue("name");
 108
 109 // Find and set engine location
 110
 111   local_element = engine_element->GetParent()->FindElement("location");
 112   if (local_element)  location = local_element->FindElementTripletConvertTo("IN");
 113   else      cerr << "No engine location found for this engine." << endl;
 114
 115   local_element = engine_element->GetParent()->FindElement("orient");
 116   if (local_element)  orientation = local_element->FindElementTripletConvertTo("DEG");
 117   else          cerr << "No engine orientation found for this engine." << endl;
 118
 119   SetPlacement(location, orientation);
 120
 121   // Load thruster
 122   local_element = engine_element->GetParent()->FindElement("thruster");
 123   if (local_element) {
 124     LoadThruster(local_element);
 125   } else {
 126     cerr << "No thruster definition supplied with engine definition." << endl;
 127   }
 128
 129   // Load feed tank[s] references
 130   local_element = engine_element->GetParent()->FindElement("feed");
 131   if (local_element) {
 132     while (local_element) {
 133       AddFeedTank((int)local_element->GetDataAsNumber());
 134       local_element = engine_element->GetParent()->FindNextElement("feed");
 135     }
 136   } else {
 137     cerr << "No feed tank specified in engine definition." << endl;
 138   }
 139
 140   Debug(0);
 141 }
 142
 143 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 144
 145 FGEngine::~FGEngine()
 146 {
 147   delete Thruster;
 148   Debug(1);
 149 }
 150
 151 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 152 // This base class function should be called from within the
 153 // derived class' Calculate() function before any other calculations are done.
 154 // This base class method removes fuel from the fuel tanks as appropriate,
 155 // and sets the starved flag if necessary.
 156
 157 void FGEngine::ConsumeFuel(void)
 158 {
 159   if (FuelFreeze) return;
 160   if (TrimMode) return;
 161
 162   unsigned int i;
 163   double Fshortage, Oshortage, TanksWithFuel, TanksWithOxidizer;
 164   FGTank* Tank;
 165   bool haveOxTanks = false;
 166   Fshortage = Oshortage = TanksWithFuel = TanksWithOxidizer = 0.0;
 167
 168   // count how many assigned tanks have fuel
 169   for (i=0; i<SourceTanks.size(); i++) {
 170     Tank = Propulsion->GetTank(SourceTanks[i]);
 171     if (Tank->GetType() == FGTank::ttFUEL){
 172       if (Tank->GetContents() > 0.0) ++TanksWithFuel;
 173     } else if (Tank->GetType() == FGTank::ttOXIDIZER) {
 174       haveOxTanks = true;
 175       if (Tank->GetContents() > 0.0) ++TanksWithOxidizer;
 176     }
 177   }
 178   if (TanksWithFuel==0 || (haveOxTanks && TanksWithOxidizer==0)) {
 179     Starved = true;
 180     return;
 181   }
 182
 183   for (i=0; i<SourceTanks.size(); i++) {
 184     Tank = Propulsion->GetTank(SourceTanks[i]);
 185     if (Tank->GetType() == FGTank::ttFUEL) {
 186        Fshortage += Tank->Drain(CalcFuelNeed()/TanksWithFuel);
 187     } else if (Tank->GetType() == FGTank::ttOXIDIZER) {
 188        Oshortage += Tank->Drain(CalcOxidizerNeed()/TanksWithOxidizer);
 189     }
 190   }
 191
 192   if (Fshortage < 0.00 || Oshortage < 0.00) Starved = true;
 193   else Starved = false;
 194 }
 195
 196 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 197
 198 double FGEngine::CalcFuelNeed(void)
 199 {
 200   FuelNeed = SLFuelFlowMax*PctPower*State->Getdt()*Propulsion->GetRate();
 201   return FuelNeed;
 202 }
 203
 204 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 205
 206 double FGEngine::CalcOxidizerNeed(void)
 207 {
 208   OxidizerNeed = SLOxiFlowMax*PctPower*State->Getdt()*Propulsion->GetRate();
 209   return OxidizerNeed;
 210 }
 211
 212 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 213
 214 void FGEngine::SetPlacement(FGColumnVector3& location, FGColumnVector3& orientation)
 215 {
 216   X = location(eX);
 217   Y = location(eY);
 218   Z = location(eZ);
 219   EnginePitch = orientation(ePitch);
 220   EngineYaw = orientation (eYaw);
 221 }
 222
 223 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 224
 225 void FGEngine::AddFeedTank(int tkID)
 226 {
 227   SourceTanks.push_back(tkID);
 228 }
 229
 230 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 231
 232 FGColumnVector3& FGEngine::GetBodyForces(void)
 233 {
 234   return Thruster->GetBodyForces();
 235 }
 236
 237 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 238
 239 FGColumnVector3& FGEngine::GetMoments(void)
 240 {
 241   return Thruster->GetMoments();
 242 }
 243
 244 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 245
 246 bool FGEngine::LoadThruster(Element *thruster_element)
 247 {
 248   string token, fullpath, localpath;
 249   string thruster_filename, thruster_fullpathname, thrType;
 250   double P_Factor = 0, Sense = 0.0;
 251   string enginePath = FDMExec->GetEnginePath();
 252   string aircraftPath = FDMExec->GetFullAircraftPath();
 253   ifstream thruster_file;
 254   FGColumnVector3 location, orientation;
 255   string separator = "/";
 256
 257 # ifdef macintosh
 258     separator = ";";
 259 # endif
 260
 261   fullpath = enginePath + separator;
 262   localpath = aircraftPath + separator + "Engines" + separator;
 263
 264   thruster_filename = thruster_element->GetAttributeValue("file");
 265   if ( !thruster_filename.empty()) {
 266     thruster_fullpathname = fullpath + thruster_filename + ".xml";
 267     thruster_file.open(thruster_fullpathname.c_str());
 268     if ( !thruster_file.is_open()) {
 269       thruster_fullpathname = localpath + thruster_filename + ".xml";
 270       thruster_file.open(thruster_fullpathname.c_str());
 271       if ( !thruster_file.is_open()) {
 272         cerr << "Could not open thruster file: " << thruster_filename << ".xml" << endl;
 273         return false;
 274       } else {
 275         thruster_file.close();
 276       }
 277     } else {
 278       thruster_file.close();
 279     }
 280   } else {
 281     cerr << "No thruster filename given." << endl;
 282     return false;
 283   }
 284
 285   document = LoadXMLDocument(thruster_fullpathname);
 286   document->SetParent(thruster_element);
 287
 288   thrType = document->GetName();
 289
 290   if (thrType == "propeller") {
 291     Thruster = new FGPropeller(FDMExec, document, EngineNumber);
 292   } else if (thrType == "nozzle") {
 293     Thruster = new FGNozzle(FDMExec, document, EngineNumber);
 294   } else if (thrType == "direct") {
 295     Thruster = new FGThruster( FDMExec, document, EngineNumber);
 296   }
 297
 298   Thruster->SetdeltaT(State->Getdt() * Propulsion->GetRate());
 299
 300   Debug(2);
 301   return true;
 302 }
 303
 304 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 305 //    The bitmasked value choices are as follows:
 306 //    unset: In this case (the default) JSBSim would only print
 307 //       out the normally expected messages, essentially echoing
 308 //       the config files as they are read. If the environment
 309 //       variable is not set, debug_lvl is set to 1 internally
 310 //    0: This requests JSBSim not to output any messages
 311 //       whatsoever.
 312 //    1: This value explicity requests the normal JSBSim
 313 //       startup messages
 314 //    2: This value asks for a message to be printed out when
 315 //       a class is instantiated
 316 //    4: When this value is set, a message is displayed when a
 317 //       FGModel object executes its Run() method
 318 //    8: When this value is set, various runtime state variables
 319 //       are printed out periodically
 320 //    16: When set various parameters are sanity checked and
 321 //       a message is printed out when they go out of bounds
 322
 323 void FGEngine::Debug(int from)
 324 {
 325   if (debug_lvl <= 0) return;
 326
 327   if (debug_lvl & 1) { // Standard console startup message output
 328     if (from == 0) { // Constructor
 329
 330     }
 331     if (from == 2) { // After thruster loading
 332       cout << "      X = " << Thruster->GetLocationX() << endl;
 333       cout << "      Y = " << Thruster->GetLocationY() << endl;
 334       cout << "      Z = " << Thruster->GetLocationZ() << endl;
 335       cout << "      Pitch = " << radtodeg*Thruster->GetAnglesToBody(ePitch) << " degrees" << endl;
 336       cout << "      Yaw = " << radtodeg*Thruster->GetAnglesToBody(eYaw) << " degrees" << endl;
 337     }
 338   }
 339   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 340     if (from == 0) cout << "Instantiated: FGEngine" << endl;
 341     if (from == 1) cout << "Destroyed:    FGEngine" << endl;
 342   }
 343   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 344   }
 345   if (debug_lvl & 8 ) { // Runtime state variables
 346   }
 347   if (debug_lvl & 16) { // Sanity checking
 348   }
 349   if (debug_lvl & 64) {
 350     if (from == 0) { // Constructor
 351       cout << IdSrc << endl;
 352       cout << IdHdr << endl;
 353     }
 354   }
 355 }
 356 }