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 #include "FGEngine.h"
  41 #include "FGTank.h"
  42 #include "FGPropeller.h"
  43 #include "FGNozzle.h"
  44 #include <input_output/FGXMLParse.h>
  45 #include <math/FGColumnVector3.h>
  46 #include <fstream>
  47
  48 namespace JSBSim {
  49
  50 static const char *IdSrc = "$Id$";
  51 static const char *IdHdr = ID_ENGINE;
  52
  53 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  54 CLASS IMPLEMENTATION
  55 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  56
  57 FGEngine::FGEngine(FGFDMExec* exec, Element* engine_element, int engine_number)
  58                       : EngineNumber(engine_number)
  59 {
  60   Element* local_element;
  61   FGColumnVector3 location, orientation;
  62
  63   Name = "";
  64   Type = etUnknown;
  65   X = Y = Z = 0.0;
  66   EnginePitch = EngineYaw = 0.0;
  67   SLFuelFlowMax = SLOxiFlowMax = 0.0;
  68   MaxThrottle = 1.0;
  69   MinThrottle = 0.0;
  70
  71   ResetToIC(); // initialize dynamic terms
  72
  73   FDMExec = exec;
  74   State = FDMExec->GetState();
  75   Atmosphere = FDMExec->GetAtmosphere();
  76   FCS = FDMExec->GetFCS();
  77   Propulsion = FDMExec->GetPropulsion();
  78   Aircraft = FDMExec->GetAircraft();
  79   Propagate = FDMExec->GetPropagate();
  80   Auxiliary = FDMExec->GetAuxiliary();
  81
  82   PropertyManager = FDMExec->GetPropertyManager();
  83
  84   Name = engine_element->GetAttributeValue("name");
  85
  86 // Find and set engine location
  87
  88   local_element = engine_element->GetParent()->FindElement("location");
  89   if (local_element)  location = local_element->FindElementTripletConvertTo("IN");
  90   else      cerr << "No engine location found for this engine." << endl;
  91
  92   local_element = engine_element->GetParent()->FindElement("orient");
  93   if (local_element)  orientation = local_element->FindElementTripletConvertTo("RAD");
  94 //  else          cerr << "No engine orientation found for this engine." << endl;
  95 // Jon: The engine orientation has a default and is not normally used.
  96
  97   SetPlacement(location, orientation);
  98
  99   // Load thruster
 100   local_element = engine_element->GetParent()->FindElement("thruster");
 101   if (local_element) {
 102     if (!LoadThruster(local_element)) exit(-1);
 103   } else {
 104     cerr << "No thruster definition supplied with engine definition." << endl;
 105   }
 106
 107   // Load feed tank[s] references
 108   local_element = engine_element->GetParent()->FindElement("feed");
 109   if (local_element) {
 110     while (local_element) {
 111       AddFeedTank((int)local_element->GetDataAsNumber());
 112       local_element = engine_element->GetParent()->FindNextElement("feed");
 113     }
 114   } else {
 115     cerr << "No feed tank specified in engine definition." << endl;
 116   }
 117
 118   char property_name[80];
 119   snprintf(property_name, 80, "propulsion/engine[%d]/set-running", EngineNumber);
 120   PropertyManager->Tie( property_name, (FGEngine*)this, &FGEngine::GetRunning,
 121                                        &FGEngine::SetRunning );
 122
 123   Debug(0);
 124 }
 125
 126 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 127
 128 FGEngine::~FGEngine()
 129 {
 130   delete Thruster;
 131   Debug(1);
 132 }
 133
 134 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 135
 136 void FGEngine::ResetToIC(void)
 137 {
 138   Thrust = 0.0;
 139   Throttle = 0.0;
 140   Mixture = 1.0;
 141   Starter = false;
 142   FuelNeed = OxidizerNeed = 0.0;
 143   Starved = Running = Cranking = false;
 144   PctPower = 0.0;
 145   TrimMode = false;
 146   FuelFlow_gph = 0.0;
 147   FuelFlow_pph = 0.0;
 148   FuelFreeze = false;
 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   fullpath = enginePath + separator;
 258   localpath = aircraftPath + separator + "Engines" + separator;
 259
 260   thruster_filename = thruster_element->GetAttributeValue("file");
 261   if ( !thruster_filename.empty()) {
 262     thruster_fullpathname = fullpath + thruster_filename + ".xml";
 263     thruster_file.open(thruster_fullpathname.c_str());
 264     if ( !thruster_file.is_open()) {
 265       thruster_fullpathname = localpath + thruster_filename + ".xml";
 266       thruster_file.open(thruster_fullpathname.c_str());
 267       if ( !thruster_file.is_open()) {
 268         cerr << "Could not open thruster file: " << thruster_filename << ".xml" << endl;
 269         return false;
 270       } else {
 271         thruster_file.close();
 272       }
 273     } else {
 274       thruster_file.close();
 275     }
 276   } else {
 277     cerr << "No thruster filename given." << endl;
 278     return false;
 279   }
 280
 281   document = LoadXMLDocument(thruster_fullpathname);
 282   document->SetParent(thruster_element);
 283
 284   thrType = document->GetName();
 285
 286   if (thrType == "propeller") {
 287     Thruster = new FGPropeller(FDMExec, document, EngineNumber);
 288   } else if (thrType == "nozzle") {
 289     Thruster = new FGNozzle(FDMExec, document, EngineNumber);
 290   } else if (thrType == "direct") {
 291     Thruster = new FGThruster( FDMExec, document, EngineNumber);
 292   }
 293
 294   Thruster->SetdeltaT(State->Getdt() * Propulsion->GetRate());
 295
 296   Debug(2);
 297   return true;
 298 }
 299
 300 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 301 //    The bitmasked value choices are as follows:
 302 //    unset: In this case (the default) JSBSim would only print
 303 //       out the normally expected messages, essentially echoing
 304 //       the config files as they are read. If the environment
 305 //       variable is not set, debug_lvl is set to 1 internally
 306 //    0: This requests JSBSim not to output any messages
 307 //       whatsoever.
 308 //    1: This value explicity requests the normal JSBSim
 309 //       startup messages
 310 //    2: This value asks for a message to be printed out when
 311 //       a class is instantiated
 312 //    4: When this value is set, a message is displayed when a
 313 //       FGModel object executes its Run() method
 314 //    8: When this value is set, various runtime state variables
 315 //       are printed out periodically
 316 //    16: When set various parameters are sanity checked and
 317 //       a message is printed out when they go out of bounds
 318
 319 void FGEngine::Debug(int from)
 320 {
 321   if (debug_lvl <= 0) return;
 322
 323   if (debug_lvl & 1) { // Standard console startup message output
 324     if (from == 0) { // Constructor
 325
 326     }
 327     if (from == 2) { // After thruster loading
 328       cout << "      X = " << Thruster->GetLocationX() << endl;
 329       cout << "      Y = " << Thruster->GetLocationY() << endl;
 330       cout << "      Z = " << Thruster->GetLocationZ() << endl;
 331       cout << "      Pitch = " << radtodeg*Thruster->GetAnglesToBody(ePitch) << " degrees" << endl;
 332       cout << "      Yaw = " << radtodeg*Thruster->GetAnglesToBody(eYaw) << " degrees" << endl;
 333     }
 334   }
 335   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 336     if (from == 0) cout << "Instantiated: FGEngine" << endl;
 337     if (from == 1) cout << "Destroyed:    FGEngine" << endl;
 338   }
 339   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 340   }
 341   if (debug_lvl & 8 ) { // Runtime state variables
 342   }
 343   if (debug_lvl & 16) { // Sanity checking
 344   }
 345   if (debug_lvl & 64) {
 346     if (from == 0) { // Constructor
 347       cout << IdSrc << endl;
 348       cout << IdHdr << endl;
 349     }
 350   }
 351 }
 352 }