fgturbine.cpp

6 DOF Missle Simulation

  return 0.0;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

double FGTurbine::Stall(void)
{
  double qbar = Auxiliary->Getqbar();
  EGT_degC = TAT + 903.14;
  FuelFlow_pph = IdleFF;
  N1 = Seek(&N1, qbar/10.0, 0, N1/10.0);
  N2 = Seek(&N2, qbar/15.0, 0, N2/10.0);
  ConsumeFuel();
  if (ThrottlePos < 0.01) phase = tpRun;        // clear the stall with throttle

  return 0.0;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

double FGTurbine::Seize(void)
{
    double qbar = Auxiliary->Getqbar();
    N2 = 0.0;
    N1 = Seek(&N1, qbar/20.0, 0, N1/15.0);
    FuelFlow_pph = IdleFF;
    ConsumeFuel();
    OilPressure_psi = 0.0;
    OilTemp_degK = Seek(&OilTemp_degK, TAT + 273.0, 0, 0.2);
    Running = false;
    return 0.0;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

double FGTurbine::Trim()
{
    double idlethrust, milthrust, thrust, tdiff, N2norm;
    idlethrust = MilThrust * IdleThrustLookup->GetValue();
    milthrust = (MilThrust - idlethrust) * MilThrustLookup->GetValue();
    N2 = IdleN2 + ThrottlePos * N2_factor;
    N2norm = (N2 - IdleN2) / N2_factor;
    thrust = (idlethrust + (milthrust * N2norm * N2norm))
          * (1.0 - BleedDemand);

    if (AugMethod == 1) {
      if ((ThrottlePos > 0.99) && (N2 > 97.0)) {Augmentation = true;}
      else {Augmentation = false;}
    }

    if ((Augmented == 1) && Augmentation && (AugMethod < 2)) {
      thrust = MaxThrust * MaxThrustLookup->GetValue();
    }

    if (AugMethod == 2) {
      if (AugmentCmd > 0.0) {
        tdiff = (MaxThrust * MaxThrustLookup->GetValue()) - thrust;
        thrust += (tdiff * AugmentCmd);
      }
    }

    if ((Injected == 1) && Injection) {
      thrust = thrust * InjectionLookup->GetValue();
    }

    return thrust;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

double FGTurbine::CalcFuelNeed(void)
{
  double dT = State->Getdt() * Propulsion->GetRate();
  FuelFlowRate = FuelFlow_pph / 3600.0; // Calculates flow in lbs/sec from lbs/hr
  FuelExpended = FuelFlowRate * dT;     // Calculates fuel expended in this time step
  return FuelExpended;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

double FGTurbine::GetPowerAvailable(void) {
  if( ThrottlePos <= 0.77 )
    return 64.94*ThrottlePos;
  else
    return 217.38*ThrottlePos - 117.38;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

double FGTurbine::Seek(double *var, double target, double accel, double decel) {
  double v = *var;
  if (v > target) {
    v -= dt * decel;
    if (v < target) v = target;
  } else if (v < target) {
    v += dt * accel;
    if (v > target) v = target;
  }
  return v;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

bool FGTurbine::Load(FGFDMExec* exec, Element *el)
{
  char property_prefix[80];
  snprintf(property_prefix, 80, "propulsion/engine[%u]/", EngineNumber);

  if (el->FindElement("milthrust"))
    MilThrust = el->FindElementValueAsNumberConvertTo("milthrust","LBS");
  if (el->FindElement("maxthrust"))
    MaxThrust = el->FindElementValueAsNumberConvertTo("maxthrust","LBS");
  if (el->FindElement("bypassratio"))
    BypassRatio = el->FindElementValueAsNumber("bypassratio");
  if (el->FindElement("bleed"))
    BleedDemand = el->FindElementValueAsNumber("bleed");
  if (el->FindElement("tsfc"))
    TSFC = el->FindElementValueAsNumber("tsfc");
  if (el->FindElement("atsfc"))
    ATSFC = el->FindElementValueAsNumber("atsfc");
  if (el->FindElement("idlen1"))
    IdleN1 = el->FindElementValueAsNumber("idlen1");
  if (el->FindElement("idlen2"))
    IdleN2 = el->FindElementValueAsNumber("idlen2");
  if (el->FindElement("maxn1"))
    MaxN1 = el->FindElementValueAsNumber("maxn1");
  if (el->FindElement("maxn2"))
    MaxN2 = el->FindElementValueAsNumber("maxn2");
  if (el->FindElement("augmented"))
    Augmented = (int)el->FindElementValueAsNumber("augmented");
  if (el->FindElement("augmethod"))
    AugMethod = (int)el->FindElementValueAsNumber("augmethod");
  if (el->FindElement("injected"))
    Injected = (int)el->FindElementValueAsNumber("injected");
  if (el->FindElement("injection-time"))
    InjectionTime = el->FindElementValueAsNumber("injection-time");

  Element *function_element;
  string name;
  FGPropertyManager* PropertyManager = exec->GetPropertyManager();

  while (true) {
    function_element = el->FindNextElement("function");
    if (!function_element) break;
    name = function_element->GetAttributeValue("name");
    if (name == "IdleThrust") {
      IdleThrustLookup = new FGFunction(PropertyManager, function_element, property_prefix);
    } else if (name == "MilThrust") {
      MilThrustLookup = new FGFunction(PropertyManager, function_element, property_prefix);
    } else if (name == "AugThrust") {
      MaxThrustLookup = new FGFunction(PropertyManager, function_element, property_prefix);
    } else if (name == "Injection") {
      InjectionLookup = new FGFunction(PropertyManager, function_element, property_prefix);
    } else {
      cerr << "Unknown function type: " << name << " in turbine definition." <<
      endl;
    }
  }

  // Pre-calculations and initializations

  delay = 60.0 / (BypassRatio + 3.0);
  N1_factor = MaxN1 - IdleN1;
  N2_factor = MaxN2 - IdleN2;
  OilTemp_degK = (Auxiliary->GetTotalTemperature() - 491.69) * 0.5555556 + 273.0;
  IdleFF = pow(MilThrust, 0.2) * 107.0;  // just an estimate

  bindmodel();
  return true;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

string FGTurbine::GetEngineLabels(string delimeter)
{
  std::ostringstream buf;

  buf << Name << "_N1[" << EngineNumber << "]" << delimeter
      << Name << "_N2[" << EngineNumber << "]" << delimeter
      << Thruster->GetThrusterLabels(EngineNumber, delimeter);

  return buf.str();
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

string FGTurbine::GetEngineValues(string delimeter)
{
  std::ostringstream buf;

  buf << N1 << delimeter
      << N2 << delimeter
      << Thruster->GetThrusterValues(EngineNumber, delimeter);

  return buf.str();
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void FGTurbine::bindmodel()
{
  char property_name[80];

  snprintf(property_name, 80, "propulsion/engine[%u]/n1", EngineNumber);
  PropertyManager->Tie( property_name, &N1);
  snprintf(property_name, 80, "propulsion/engine[%u]/n2", EngineNumber);
  PropertyManager->Tie( property_name, &N2);
  snprintf(property_name, 80, "propulsion/engine[%u]/injection_cmd", EngineNumber);
  PropertyManager->Tie( property_name, (FGTurbine*)this, 
                        &FGTurbine::GetInjection, &FGTurbine::SetInjection);
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

int FGTurbine::InitRunning(void) {
  State->SuspendIntegration();
  Cutoff=false;
  Running=true;  
  N2=16.0;
  Calculate();
  State->ResumeIntegration();
  return phase==tpRun;
}

//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
//    The bitmasked value choices are as follows:
//    unset: In this case (the default) JSBSim would only print
//       out the normally expected messages, essentially echoing
//       the config files as they are read. If the environment
//       variable is not set, debug_lvl is set to 1 internally
//    0: This requests JSBSim not to output any messages
//       whatsoever.
//    1: This value explicity requests the normal JSBSim
//       startup messages
//    2: This value asks for a message to be printed out when
//       a class is instantiated
//    4: When this value is set, a message is displayed when a
//       FGModel object executes its Run() method
//    8: When this value is set, various runtime state variables
//       are printed out periodically
//    16: When set various parameters are sanity checked and
//       a message is printed out when they go out of bounds

void FGTurbine::Debug(int from)
{
  if (debug_lvl <= 0) return;

  if (debug_lvl & 1) { // Standard console startup message output
    if (from == 0) { // Constructor

    }
    if (from == 2) { // called from Load()
      cout << "\n    Engine Name: "         << Name << endl;
      cout << "      MilThrust:   "         << MilThrust << endl;
      cout << "      MaxThrust:   "         << MaxThrust << endl;
      cout << "      BypassRatio: "         << BypassRatio << endl;
      cout << "      TSFC:        "         << TSFC << endl;
      cout << "      ATSFC:       "         << ATSFC << endl;
      cout << "      IdleN1:      "         << IdleN1 << endl;
      cout << "      IdleN2:      "         << IdleN2 << endl;
      cout << "      MaxN1:       "         << MaxN1 << endl;
      cout << "      MaxN2:       "         << MaxN2 << endl;
      cout << "      Augmented:   "         << Augmented << endl;
      cout << "      AugMethod:   "         << AugMethod << endl;
      cout << "      Injected:    "         << Injected << endl;
      cout << "      MinThrottle: "         << MinThrottle << endl;

      cout << endl;
    }
  }
  if (debug_lvl & 2 ) { // Instantiation/Destruction notification
    if (from == 0) cout << "Instantiated: FGTurbine" << endl;
    if (from == 1) cout << "Destroyed:    FGTurbine" << endl;
  }
  if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
  }
  if (debug_lvl & 8 ) { // Runtime state variables
  }
  if (debug_lvl & 16) { // Sanity checking
  }
  if (debug_lvl & 64) {
    if (from == 0) { // Constructor
      cout << IdSrc << endl;
      cout << IdHdr << endl;
    }
  }
}
}