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 = 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, this, &FGEngine::GetRunning, &FGEngine::SetRunning );
 121   snprintf(property_name, 80, "propulsion/engine[%u]/thrust-lbs", EngineNumber);
 122   PropertyManager->Tie( property_name, Thruster, &FGThruster::GetThrust);
 123   snprintf(property_name, 80, "propulsion/engine[%u]/fuel-flow-rate-pps", EngineNumber);
 124   PropertyManager->Tie( property_name, this, &FGEngine::GetFuelFlowRate);
 125
 126   Debug(0);
 127 }
 128
 129 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 130
 131 FGEngine::~FGEngine()
 132 {
 133   delete Thruster;
 134   Debug(1);
 135 }
 136
 137 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 138
 139 void FGEngine::ResetToIC(void)
 140 {
 141   Throttle = 0.0;
 142   Mixture = 1.0;
 143   Starter = false;
 144   FuelExpended = 0.0;
 145   Starved = Running = Cranking = false;
 146   PctPower = 0.0;
 147   TrimMode = false;
 148   FuelFlow_gph = 0.0;
 149   FuelFlow_pph = 0.0;
 150   FuelFreeze = false;
 151 }
 152
 153 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 154 // This base class function should be called from within the
 155 // derived class' Calculate() function before any other calculations are done.
 156 // This base class method removes fuel from the fuel tanks as appropriate,
 157 // and sets the starved flag if necessary.
 158 // This version of the fuel consumption code should never see an oxidizer tank.
 159
 160 void FGEngine::ConsumeFuel(void)
 161 {
 162   if (FuelFreeze) return;
 163   if (TrimMode) return;
 164
 165   unsigned int i;
 166   double Fshortage, TanksWithFuel;
 167   FGTank* Tank;
 168   Fshortage = TanksWithFuel = 0.0;
 169
 170   // count how many assigned tanks have fuel
 171   for (i=0; i<SourceTanks.size(); i++) {
 172     Tank = Propulsion->GetTank(SourceTanks[i]);
 173     if (Tank->GetType() == FGTank::ttFUEL){
 174       if (Tank->GetContents() > 0.0) ++TanksWithFuel;
 175     } else {
 176        cerr << "No oxidizer tanks should be used for this engine type." << endl;
 177     }
 178   }
 179   if (TanksWithFuel==0) {
 180     Starved = true;
 181     return;
 182   }
 183
 184   for (i=0; i<SourceTanks.size(); i++) {
 185     Tank = Propulsion->GetTank(SourceTanks[i]);
 186     if (Tank->GetType() == FGTank::ttFUEL) {
 187        Fshortage += Tank->Drain(CalcFuelNeed()/TanksWithFuel);
 188     } else {
 189        cerr << "No oxidizer tanks should be used for this engine type." << endl;
 190     }
 191   }
 192
 193   if (Fshortage < 0.00) Starved = true;
 194   else Starved = false;
 195 }
 196
 197 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 198
 199 double FGEngine::CalcFuelNeed(void)
 200 {
 201   double dT = State->Getdt()*Propulsion->GetRate();
 202   FuelFlowRate = SLFuelFlowMax*PctPower;
 203   FuelExpended = FuelFlowRate*dT;
 204   return FuelExpended;
 205 }
 206
 207 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 208
 209 void FGEngine::SetPlacement(FGColumnVector3& location, FGColumnVector3& orientation)
 210 {
 211   X = location(eX);
 212   Y = location(eY);
 213   Z = location(eZ);
 214   EnginePitch = orientation(ePitch);
 215   EngineYaw = orientation (eYaw);
 216 }
 217
 218 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 219
 220 void FGEngine::AddFeedTank(int tkID)
 221 {
 222   SourceTanks.push_back(tkID);
 223 }
 224
 225 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 226
 227 FGColumnVector3& FGEngine::GetBodyForces(void)
 228 {
 229   return Thruster->GetBodyForces();
 230 }
 231
 232 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 233
 234 FGColumnVector3& FGEngine::GetMoments(void)
 235 {
 236   return Thruster->GetMoments();
 237 }
 238
 239 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 240
 241 bool FGEngine::LoadThruster(Element *thruster_element)
 242 {
 243   string token, fullpath, localpath;
 244   string thruster_filename, thruster_fullpathname, thrType;
 245   double P_Factor = 0, Sense = 0.0;
 246   string enginePath = FDMExec->GetEnginePath();
 247   string aircraftPath = FDMExec->GetFullAircraftPath();
 248   ifstream thruster_file;
 249   FGColumnVector3 location, orientation;
 250   string separator = "/";
 251
 252   fullpath = enginePath + separator;
 253   localpath = aircraftPath + separator + "Engines" + separator;
 254
 255   thruster_filename = thruster_element->GetAttributeValue("file");
 256   if ( !thruster_filename.empty()) {
 257     thruster_fullpathname = fullpath + thruster_filename + ".xml";
 258     thruster_file.open(thruster_fullpathname.c_str());
 259     if ( !thruster_file.is_open()) {
 260       thruster_fullpathname = localpath + thruster_filename + ".xml";
 261       thruster_file.open(thruster_fullpathname.c_str());
 262       if ( !thruster_file.is_open()) {
 263         cerr << "Could not open thruster file: " << thruster_filename << ".xml" << endl;
 264         return false;
 265       } else {
 266         thruster_file.close();
 267       }
 268     } else {
 269       thruster_file.close();
 270     }
 271   } else {
 272     cerr << "No thruster filename given." << endl;
 273     return false;
 274   }
 275
 276   document = LoadXMLDocument(thruster_fullpathname);
 277   document->SetParent(thruster_element);
 278
 279   thrType = document->GetName();
 280
 281   if (thrType == "propeller") {
 282     Thruster = new FGPropeller(FDMExec, document, EngineNumber);
 283   } else if (thrType == "nozzle") {
 284     Thruster = new FGNozzle(FDMExec, document, EngineNumber);
 285   } else if (thrType == "direct") {
 286     Thruster = new FGThruster( FDMExec, document, EngineNumber);
 287   }
 288
 289   Thruster->SetdeltaT(State->Getdt() * Propulsion->GetRate());
 290
 291   Debug(2);
 292   return true;
 293 }
 294
 295 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 296 //    The bitmasked value choices are as follows:
 297 //    unset: In this case (the default) JSBSim would only print
 298 //       out the normally expected messages, essentially echoing
 299 //       the config files as they are read. If the environment
 300 //       variable is not set, debug_lvl is set to 1 internally
 301 //    0: This requests JSBSim not to output any messages
 302 //       whatsoever.
 303 //    1: This value explicity requests the normal JSBSim
 304 //       startup messages
 305 //    2: This value asks for a message to be printed out when
 306 //       a class is instantiated
 307 //    4: When this value is set, a message is displayed when a
 308 //       FGModel object executes its Run() method
 309 //    8: When this value is set, various runtime state variables
 310 //       are printed out periodically
 311 //    16: When set various parameters are sanity checked and
 312 //       a message is printed out when they go out of bounds
 313
 314 void FGEngine::Debug(int from)
 315 {
 316   if (debug_lvl <= 0) return;
 317
 318   if (debug_lvl & 1) { // Standard console startup message output
 319     if (from == 0) { // Constructor
 320
 321     }
 322     if (from == 2) { // After thruster loading
 323       cout << "      X = " << Thruster->GetLocationX() << endl;
 324       cout << "      Y = " << Thruster->GetLocationY() << endl;
 325       cout << "      Z = " << Thruster->GetLocationZ() << endl;
 326       cout << "      Pitch = " << radtodeg*Thruster->GetAnglesToBody(ePitch) << " degrees" << endl;
 327       cout << "      Yaw = " << radtodeg*Thruster->GetAnglesToBody(eYaw) << " degrees" << endl;
 328     }
 329   }
 330   if (debug_lvl & 2 ) { // Instantiation/Destruction notification
 331     if (from == 0) cout << "Instantiated: FGEngine" << endl;
 332     if (from == 1) cout << "Destroyed:    FGEngine" << endl;
 333   }
 334   if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
 335   }
 336   if (debug_lvl & 8 ) { // Runtime state variables
 337   }
 338   if (debug_lvl & 16) { // Sanity checking
 339   }
 340   if (debug_lvl & 64) {
 341     if (from == 0) { // Constructor
 342       cout << IdSrc << endl;
 343       cout << IdHdr << endl;
 344     }
 345   }
 346 }
 347 }