FGPiston.h

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 Header:       FGPiston.h
 Author:       Jon S. Berndt
 Date started: 09/12/2000
 
 ------------- Copyright (C) 2000  Jon S. Berndt (jon@jsbsim.org) --------------
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser General Public License as published by the Free Software
 Foundation; either version 2 of the License, or (at your option) any later
 version.
 
 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
 details.
 
 You should have received a copy of the GNU Lesser General Public License along with
 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 Place - Suite 330, Boston, MA  02111-1307, USA.
 
 Further information about the GNU Lesser General Public License can also be found on
 the world wide web at http://www.gnu.org.
 
HISTORY
--------------------------------------------------------------------------------
09/12/2000  JSB  Created
10/01/2001  DPM  Modified to use equations from Dave Luff's piston model.
11/01/2008  RKJ  Modified piston engine model for more general use.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
SENTRY
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
#ifndef FGPISTON_H
#define FGPISTON_H
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
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#include "FGEngine.h"
#include "math/FGTable.h"
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
DEFINITIONS
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#define FG_MAX_BOOST_SPEEDS 3
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FORWARD DECLARATIONS
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namespace JSBSim {
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS DOCUMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS DECLARATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
class FGPiston : public FGEngine
{
public:
  FGPiston(FGFDMExec* exec, Element* el, int engine_number, struct Inputs& input);
  ~FGPiston();
 
  std::string GetEngineLabels(const std::string& delimiter);
  std::string GetEngineValues(const std::string& delimiter);
 
  void Calculate(void);
  double GetPowerAvailable(void) const {return (HP * hptoftlbssec);}
  double CalcFuelNeed(void);
 
  void ResetToIC(void);
  void SetMagnetos(int magnetos) {Magnetos = magnetos;}
 
  double  GetEGT(void) const { return EGT_degC; }
  int     GetMagnetos(void) const {return Magnetos;}
 
  double getExhaustGasTemp_degF(void) const {return KelvinToFahrenheit(ExhaustGasTemp_degK);}
  double getManifoldPressure_inHg(void) const {return ManifoldPressure_inHg;}
  double getCylinderHeadTemp_degF(void) const {return KelvinToFahrenheit(CylinderHeadTemp_degK);}
  double getOilPressure_psi(void) const {return OilPressure_psi;}
  double getOilTemp_degF (void) const {return KelvinToFahrenheit(OilTemp_degK);}
  double getRPM(void) const {return RPM;}
  double getAFR(void) const {return m_dot_fuel > 0.0 ? m_dot_air / m_dot_fuel : INFINITY;}
 
protected:
 
private:
  int crank_counter = 0;
 
  double IndicatedHorsePower = 0.0;
  //double IndicatedPower;
  double PMEP = 0.0;
  double FMEP = 0.0;
  double FMEPDynamic = 0.0;
  double FMEPStatic = 0.0;
  //double T_Intake;
 
  void doEngineStartup(void);
  void doBoostControl(void);
  void doMAP(void);
  void doAirFlow(void);
  void doFuelFlow(void);
  void doEnginePower(void);
  void doEGT(void);
  void doCHT(void);
  void doOilPressure(void);
  void doOilTemperature(void);
  double GetStdPressure100K(double altitude) const;
 
  int InitRunning(void);
 
  //
  // constants
  //
 
  const double R_air;
  //const double rho_fuel;    // kg/m^3
  const double calorific_value_fuel;  // J/Kg (approximate)
  const double Cp_air;      // J/KgK
  const double Cp_fuel;     // J/KgK
  const double standard_pressure; //Pa
 
 
  FGTable *Lookup_Combustion_Efficiency;
  FGTable *Mixture_Efficiency_Correlation;
 
  //
  // Configuration
  //
  double MinManifoldPressure_inHg = 0.0; // Inches Hg
  double MaxManifoldPressure_inHg = 0.0; // Inches Hg
  //double MaxManifoldPressure_Percent; // MaxManifoldPressure / 29.92
  double ManifoldPressureLag = 0.0;      // Manifold Pressure delay in seconds.
  double Displacement = 0.0;             // cubic inches
  double displacement_SI = 0.0;          // cubic meters
  double MaxHP = 0.0;                    // horsepower
  double StaticFriction_HP = 0.0;        // horsepower: amount subtracted from final engine power
  double SparkFailDrop = 0.0;            // drop of power due to spark failure
  double Cycles = 0.0;                   // cycles/power stroke
  double IdleRPM = 0.0;                  // revolutions per minute
  double MaxRPM = 0.0;                   // revolutions per minute
  double Bore = 0.0;                     // inches
  double Stroke = 0.0;                   // inches
  double Cylinders = 0.0;                // number
  double CylinderHeadMass = 0.0;         // kilograms
  double CompressionRatio = 0.0;         // number
  double Z_airbox = 0.0; // number representing intake impediance before the throttle
  double Z_throttle = 0.0; // number representing slope of throttle impediance
  double PeakMeanPistonSpeed_fps = 0.0; // ft/sec speed where intake valves begin to choke. Typically 33-50 fps
  double RatedMeanPistonSpeed_fps = 0.0; // ft/sec derived from MaxRPM and stroke.
  double Ram_Air_Factor = 0.0;           // number
 
  double StarterTorque = 0.0;// Peak Torque of the starter motor
  double StarterRPM = 0.0;   // Peak RPM of the starter motor
  double StarterGain = 0.0;  // control the torque of the starter motor.
  int BoostSpeeds = 0;  // Number of super/turbocharger boost speeds - zero implies no turbo/supercharging.
  int BoostSpeed = 0;   // The current boost-speed (zero-based).
  bool Boosted = false;     // Set true for boosted engine.
  int BoostManual = 0;  // The raw value read in from the config file - should be 1 or 0 - see description below.
  bool bBoostManual = false;    // Set true if pilot must manually control the boost speed.
  int BoostOverride = 0;    // The raw value read in from the config file - should be 1 or 0 - see description below.
  bool bBoostOverride = false;  // Set true if pilot override of the boost regulator was fitted.
              // (Typically called 'war emergency power').
  bool bTakeoffBoost = false;   // Set true if extra takeoff / emergency boost above rated boost could be attained.
              // (Typically by extra throttle movement past a mechanical 'gate').
  double TakeoffBoost = 0.0;  // Sea-level takeoff boost in psi. (if fitted).
  double RatedBoost[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0};   // Sea-level rated boost in psi.
  double RatedAltitude[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0};    // Altitude at which full boost is reached (boost regulation ends)
                          // and at which power starts to fall with altitude [ft].
  double RatedRPM[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0}; // Engine speed at which the rated power for each boost speed is delivered [rpm].
  double RatedPower[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0};   // Power at rated throttle position at rated altitude [HP].
  double BoostSwitchAltitude[FG_MAX_BOOST_SPEEDS - 1] = {0.0, 0.0};  // Altitude at which switchover (currently assumed automatic)
                              // from one boost speed to next occurs [ft].
  double BoostSwitchPressure[FG_MAX_BOOST_SPEEDS - 1] = {0.0, 0.0};  // Pressure at which boost speed switchover occurs [Pa]
  double BoostMul[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0}; // Pressure multiplier of unregulated supercharger
  double RatedMAP[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0}; // Rated manifold absolute pressure [Pa] (BCV clamp)
  double TakeoffMAP[FG_MAX_BOOST_SPEEDS] = {0.0, 0.0, 0.0};   // Takeoff setting manifold absolute pressure [Pa] (BCV clamp)
  double BoostSwitchHysteresis = 0.0; // Pa.
  double BoostLossFactor = 0.0; // multiplier for HP consumed by the supercharger
 
  double minMAP = 0.0;  // Pa
  double maxMAP = 0.0;  // Pa
  double MAP = 0.0;     // Pa
  double TMAP = 0.0;    // Pa - throttle manifold pressure e.g. before the supercharger boost
  double ISFC = 0.0;    // Indicated specific fuel consumption [lbs/horsepower*hour
 
  //
  // Inputs (in addition to those in FGEngine).
  //
  double p_amb = 0.0;              // Pascals
  double p_ram = 0.0;              // Pascals
  double T_amb = 0.0;              // degrees Kelvin
  double RPM = 0.0;                // revolutions per minute
  double IAS = 0.0;                // knots
  double Cooling_Factor = 0.0;     // normal
  bool Magneto_Left = false;
  bool Magneto_Right = false;
  int Magnetos = 0;
 
  double Oil_Press_Relief_Valve = 0.0;
  double Oil_Press_RPM_Max = 0.0;
  double Design_Oil_Temp = 0.0;         // degK
  double Oil_Viscosity_Index = 0.0;
 
  //
  // Outputs (in addition to those in FGEngine).
  //
  double rho_air = 0.0;
  double volumetric_efficiency = 0.0;
  double volumetric_efficiency_reduced = 0.0;
  //double map_coefficient;
  double m_dot_air = 0.0;
  double v_dot_air = 0.0;
  double equivalence_ratio = 0.0;
  double m_dot_fuel = 0.0;
  double HP = 0.0;
  double BoostLossHP = 0.0;
  double combustion_efficiency = 0.0;
  double ExhaustGasTemp_degK = 0.0;
  double EGT_degC = 0.0;
  double ManifoldPressure_inHg = 0.0;
  double CylinderHeadTemp_degK = 0.0;
  double OilPressure_psi = 0.0;
  double OilTemp_degK = 0.0;
  double MeanPistonSpeed_fps = 0.0;
 
  void Debug(int from);
};
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
#endif