Detailed Description

Turboprop engine model.

For an example of this model in use see the file: engine/engtm601.xml

Configuration parameters:

milthrust   [LBS]
idlen1      [%]
maxn1       [%]
betarangeend[%]
    if ThrottleCmd < betarangeend/100.0 then engine power=idle, propeller pitch
    is controled by ThrottleCmd (between MINPITCH and  REVERSEPITCH).
    if ThrottleCmd > betarangeend/100.0 then engine power increases up to max reverse power
reversemaxpower [%]
    max engine power in reverse mode
maxpower    [HP]
psfc power specific fuel consumption [pph/HP] for N1=100%
n1idle_max_delay [-] time constant for N1 change
maxstartenginetime [sec]
    after this time the automatic starting cycle is interrupted when the engine
    doesn't start (0=automatic starting not present)
startern1   [%]
    when starting starter spin up engine to this spin
ielumaxtorque [lb.ft]
    if torque>ielumaxtorque limiters decrease the throttle
    (ielu = Integrated Electronic Limiter Unit)
itt_delay [-] time constant for ITT change
    (ITT = Inter Turbine Temperature)

Definition at line 92 of file FGTurboProp.h.

#include <FGTurboProp.h>

Inheritance diagram for FGTurboProp:

Collaboration diagram for FGTurboProp:

Public Types
enum	phaseType { tpOff , tpRun , tpSpinUp , tpStart , tpTrim }

Public Types inherited from FGEngine
enum	EngineType { etUnknown , etRocket , etPiston , etTurbine , etTurboprop , etElectric }

Public Types inherited from FGJSBBase
enum	{ eL = 1 , eM , eN }
	Moments L, M, N. More...

enum	{ eP = 1 , eQ , eR }
	Rates P, Q, R. More...

enum	{ eU = 1 , eV , eW }
	Velocities U, V, W. More...

enum	{ eX = 1 , eY , eZ }
	Positions X, Y, Z. More...

enum	{ ePhi = 1 , eTht , ePsi }
	Euler angles Phi, Theta, Psi. More...

enum	{ eDrag = 1 , eSide , eLift }
	Stability axis forces, Drag, Side force, Lift. More...

enum	{ eRoll = 1 , ePitch , eYaw }
	Local frame orientation Roll, Pitch, Yaw. More...

enum	{ eNorth = 1 , eEast , eDown }
	Local frame position North, East, Down. More...

enum	{ eLat = 1 , eLong , eRad }
	Locations Radius, Latitude, Longitude. More...

enum	{ inNone = 0 , inDegrees , inRadians , inMeters , inFeet }
	Conversion specifiers. More...

Public Member Functions
	FGTurboProp (FGFDMExec Executive, Element el, int engine_number, struct Inputs &input)
	Constructor.

double	CalcFuelNeed (void)
	The fuel need is calculated based on power levels and flow rate for that power level.

void	Calculate (void)
	Calculates the thrust of the engine, and other engine functions.

double	ExpSeek (double *var, double target, double accel, double decel)

int	GetCondition (void) const

bool	GetCutoff (void) const

std::string	GetEngineLabels (const std::string &delimiter)

std::string	GetEngineValues (const std::string &delimiter)

double	GetEngStarting (void) const

bool	GetGeneratorPower (void) const

bool	GetIeluIntervent (void) const

double	GetIeluThrottle (void) const

double	GetITT (void) const

double	GetN1 (void) const

double	getOilPressure_psi () const

double	getOilTemp_degF (void)

phaseType	GetPhase (void) const

double	GetPowerAvailable (void) const

bool	GetReversed (void) const

double	GetRPM (void) const

int	InitRunning (void)

double	Seek (double *var, double target, double accel, double decel)

void	SetCondition (bool c)

void	SetCutoff (bool cutoff)

void	SetGeneratorPower (bool gp)

void	SetPhase (phaseType p)

void	SetReverse (bool reversed)

Public Member Functions inherited from FGEngine
	FGEngine (int engine_number, struct Inputs &input)

virtual double	CalcOxidizerNeed (void)

virtual const FGColumnVector3 &	GetBodyForces (void)

virtual bool	GetCranking (void) const

virtual double	getFuelFlow_gph () const

virtual double	getFuelFlow_pph () const

virtual double	GetFuelFlowRate (void) const

virtual double	GetFuelFlowRateGPH (void) const

virtual double	GetFuelUsedLbs (void) const

virtual const FGColumnVector3 &	GetMoments (void)

virtual const std::string &	GetName (void) const

size_t	GetNumSourceTanks () const

virtual double	GetPowerAvailable (void)

virtual bool	GetRunning (void) const

unsigned int	GetSourceTank (unsigned int i) const

virtual bool	GetStarter (void) const

virtual bool	GetStarved (void) const

virtual double	GetThrottleMax (void) const

virtual double	GetThrottleMin (void) const

virtual double	GetThrust (void) const

FGThruster *	GetThruster (void) const

EngineType	GetType (void) const

void	LoadThruster (FGFDMExec exec, Element el)

void	LoadThrusterInputs ()

virtual void	ResetToIC (void)
	Resets the Engine parameters to the initial conditions.

virtual void	SetFuelDensity (double d)

virtual void	SetFuelFreeze (bool f)

virtual void	SetName (const std::string &name)

virtual void	SetRunning (bool bb)

virtual void	SetStarter (bool s)

virtual void	SetStarved (bool tt)

virtual void	SetStarved (void)

Public Member Functions inherited from FGModelFunctions
std::string	GetFunctionStrings (const std::string &delimeter) const
	Gets the strings for the current set of functions.

std::string	GetFunctionValues (const std::string &delimeter) const
	Gets the function values.

std::shared_ptr< FGFunction >	GetPreFunction (const std::string &name)
	Get one of the "pre" function.

bool	Load (Element el, FGFDMExec fdmex, std::string prefix="")

void	PostLoad (Element el, FGFDMExec fdmex, std::string prefix="")

void	PreLoad (Element el, FGFDMExec fdmex, std::string prefix="")

void	RunPostFunctions (void)

void	RunPreFunctions (void)

Public Member Functions inherited from FGJSBBase
	FGJSBBase ()
	Constructor for FGJSBBase.

virtual	~FGJSBBase ()
	Destructor for FGJSBBase.

void	disableHighLighting (void)
	Disables highlighting in the console output.

Additional Inherited Members
Static Public Member Functions inherited from FGJSBBase
static const std::string &	GetVersion (void)
	Returns the version number of JSBSim.

static constexpr double	KelvinToFahrenheit (double kelvin)
	Converts from degrees Kelvin to degrees Fahrenheit.

static constexpr double	CelsiusToRankine (double celsius)
	Converts from degrees Celsius to degrees Rankine.

static constexpr double	RankineToCelsius (double rankine)
	Converts from degrees Rankine to degrees Celsius.

static constexpr double	KelvinToRankine (double kelvin)
	Converts from degrees Kelvin to degrees Rankine.

static constexpr double	RankineToKelvin (double rankine)
	Converts from degrees Rankine to degrees Kelvin.

static constexpr double	FahrenheitToCelsius (double fahrenheit)
	Converts from degrees Fahrenheit to degrees Celsius.

static constexpr double	CelsiusToFahrenheit (double celsius)
	Converts from degrees Celsius to degrees Fahrenheit.

static constexpr double	CelsiusToKelvin (double celsius)
	Converts from degrees Celsius to degrees Kelvin.

static constexpr double	KelvinToCelsius (double kelvin)
	Converts from degrees Kelvin to degrees Celsius.

static constexpr double	FeetToMeters (double measure)
	Converts from feet to meters.

static bool	EqualToRoundoff (double a, double b)
	Finite precision comparison.

static bool	EqualToRoundoff (float a, float b)
	Finite precision comparison.

static bool	EqualToRoundoff (float a, double b)
	Finite precision comparison.

static bool	EqualToRoundoff (double a, float b)
	Finite precision comparison.

static constexpr double	Constrain (double min, double value, double max)
	Constrain a value between a minimum and a maximum value.

static constexpr double	sign (double num)

Public Attributes inherited from FGEngine
struct Inputs &	in

Static Public Attributes inherited from FGJSBBase
static char	highint [5] = {27, '[', '1', 'm', '\0' }
	highlights text

static char	halfint [5] = {27, '[', '2', 'm', '\0' }
	low intensity text

static char	normint [6] = {27, '[', '2', '2', 'm', '\0' }
	normal intensity text

static char	reset [5] = {27, '[', '0', 'm', '\0' }
	resets text properties

static char	underon [5] = {27, '[', '4', 'm', '\0' }
	underlines text

static char	underoff [6] = {27, '[', '2', '4', 'm', '\0' }
	underline off

static char	fgblue [6] = {27, '[', '3', '4', 'm', '\0' }
	blue text

static char	fgcyan [6] = {27, '[', '3', '6', 'm', '\0' }
	cyan text

static char	fgred [6] = {27, '[', '3', '1', 'm', '\0' }
	red text

static char	fggreen [6] = {27, '[', '3', '2', 'm', '\0' }
	green text

static char	fgdef [6] = {27, '[', '3', '9', 'm', '\0' }
	default text

static short	debug_lvl = 1

Protected Member Functions inherited from FGEngine
void	Debug (int from)

bool	Load (FGFDMExec exec, Element el)

Protected Member Functions inherited from FGModelFunctions
virtual bool	InitModel (void)

Static Protected Member Functions inherited from FGJSBBase
static std::string	CreateIndexedPropertyName (const std::string &Property, int index)

Protected Attributes inherited from FGEngine
bool	Cranking

const int	EngineNumber

double	FuelDensity

double	FuelExpended

double	FuelFlow_gph

double	FuelFlow_pph

double	FuelFlowRate

bool	FuelFreeze

double	FuelUsedLbs

double	MaxThrottle

double	MinThrottle

std::string	Name

double	PctPower

bool	Running

double	SLFuelFlowMax

std::vector< int >	SourceTanks

bool	Starter

bool	Starved

FGThruster *	Thruster

EngineType	Type

Protected Attributes inherited from FGModelFunctions
FGPropertyReader	LocalProperties

std::vector< std::shared_ptr< FGFunction > >	PostFunctions

std::vector< std::shared_ptr< FGFunction > >	PreFunctions

Static Protected Attributes inherited from FGJSBBase
static constexpr double	radtodeg = 180. / M_PI

static constexpr double	degtorad = M_PI / 180.

static constexpr double	hptoftlbssec = 550.0

static constexpr double	psftoinhg = 0.014138

static constexpr double	psftopa = 47.88

static constexpr double	fttom = 0.3048

static constexpr double	ktstofps = 1852./(3600*fttom)

static constexpr double	fpstokts = 1.0 / ktstofps

static constexpr double	inchtoft = 1.0/12.0

static constexpr double	m3toft3 = 1.0/(fttomfttomfttom)

static constexpr double	in3tom3 = inchtoftinchtoftinchtoft/m3toft3

static constexpr double	inhgtopa = 3386.38

static constexpr double	slugtolb = 32.174049
	Note that definition of lbtoslug by the inverse of slugtolb and not to a different constant you can also get from some tables will make lbtoslug*slugtolb == 1 up to the magnitude of roundoff.

static constexpr double	lbtoslug = 1.0/slugtolb

static constexpr double	kgtolb = 2.20462

static constexpr double	kgtoslug = 0.06852168

static const std::string	needed_cfg_version = "2.0"

static const std::string	JSBSim_version = JSBSIM_VERSION " " __DATE__ " " __TIME__

Member Enumeration Documentation

◆ phaseType

enum phaseType

Definition at line 101 of file FGTurboProp.h.

101{ tpOff, tpRun, tpSpinUp, tpStart, tpTrim };

Constructor & Destructor Documentation

◆ FGTurboProp()

FGTurboProp	(	FGFDMExec *	Executive,
		Element *	el,
		int	engine_number,
		struct Inputs &	input
	)

Constructor.

Parameters

Executive	pointer to executive structure
el	pointer to the XML element representing the turbine engine
engine_number	engine number

Definition at line 62 of file FGTurboProp.cpp.

  : FGEngine(engine_number, input)
{
  SetDefaults();
  Load(exec, el);
  Debug(0);
}

Member Function Documentation

◆ CalcFuelNeed()

double CalcFuelNeed ( void )

virtual

The fuel need is calculated based on power levels and flow rate for that power level.

It is also turned from a rate into an actual amount (pounds) by multiplying it by the delta T and the rate.

Returns: Total fuel requirement for this engine in pounds.

Reimplemented from FGEngine.

Definition at line 425 of file FGTurboProp.cpp.

{
  FuelFlowRate = FuelFlow_pph / 3600.0;
  FuelExpended = FuelFlowRate * in.TotalDeltaT;
  if (!Starved) FuelUsedLbs += FuelExpended;
  return FuelExpended;
}

◆ Calculate()

void Calculate ( void )

virtual

Calculates the thrust of the engine, and other engine functions.

Implements FGEngine.

Definition at line 182 of file FGTurboProp.cpp.

{
  RunPreFunctions();
 
  ThrottlePos = in.ThrottlePos[EngineNumber];
 
  /* The thruster controls the engine RPM because it encapsulates the gear ratio
     and other transmission variables */
  RPM = Thruster->GetEngineRPM();
  if (thrusterType == FGThruster::ttPropeller) {
    ((FGPropeller*)Thruster)->SetAdvance(in.PropAdvance[EngineNumber]);
    ((FGPropeller*)Thruster)->SetFeather(in.PropFeather[EngineNumber]);
    ((FGPropeller*)Thruster)->SetReverse(Reversed);
    if (Reversed) {
      ((FGPropeller*)Thruster)->SetReverseCoef(ThrottlePos);
    } else {
      ((FGPropeller*)Thruster)->SetReverseCoef(0.0);
    }
 
    if (Reversed) {
      if (ThrottlePos < BetaRangeThrottleEnd) {
          ThrottlePos = 0.0;  // idle when in Beta-range
      } else {
        // when reversed:
        ThrottlePos = (ThrottlePos-BetaRangeThrottleEnd)/(1-BetaRangeThrottleEnd) * ReverseMaxPower;
      }
    }
  }
 
  // When trimming is finished check if user wants engine OFF or RUNNING
  if ((phase == tpTrim) && (in.TotalDeltaT > 0)) {
    if (Running && !Starved) {
      phase = tpRun;
      N1 = IdleN1;
      OilTemp_degK = 366.0;
      Cutoff = false;
    } else {
      phase = tpOff;
      Cutoff = true;
      Eng_ITT_degC = in.TAT_c;
      Eng_Temperature = in.TAT_c;
      OilTemp_degK = in.TAT_c+273.15;
    }
  }
 
  if (!Running && Starter) {
    if (phase == tpOff) {
      phase = tpSpinUp;
      if (StartTime < 0) StartTime=0;
    }
  }
  if (!Running && !Cutoff && (N1 > 15.0)) {
    phase = tpStart;
    StartTime = -1;
  }
  if (Cutoff && (phase != tpSpinUp)) phase = tpOff;
  if (in.TotalDeltaT == 0) phase = tpTrim;
  if (Starved) phase = tpOff;
  if (Condition >= 10) {
    phase = tpOff;
    StartTime=-1;
  }
 
  // limiter intervention wanted?
  if (Ielu_max_torque > 0.0) {
    double torque = 0.0;
 
    if (thrusterType == FGThruster::ttPropeller) {
      torque = ((FGPropeller*)(Thruster))->GetTorque();
    } else if (thrusterType == FGThruster::ttRotor) {
      torque = ((FGRotor*)(Thruster))->GetTorque();
    }
 
    if (Condition < 1) {
      if ( abs(torque) > Ielu_max_torque && ThrottlePos >= OldThrottle ) {
        ThrottlePos = OldThrottle - 0.1 * in.TotalDeltaT; //IELU down
        Ielu_intervent = true;
      } else if ( Ielu_intervent && ThrottlePos >= OldThrottle) {
        ThrottlePos = OldThrottle + 0.05 * in.TotalDeltaT; //IELU up
        Ielu_intervent = true;
      } else {
        Ielu_intervent = false;
      }
    } else {
      Ielu_intervent = false;
    }
    OldThrottle = ThrottlePos;
  }
 
  switch (phase) {
    case tpOff:    HP = Off(); break;
    case tpRun:    HP = Run(); break;
    case tpSpinUp: HP = SpinUp(); break;
    case tpStart:  HP = Start(); break;
    default: HP = 0;
  }
 
  LoadThrusterInputs();
  // Filters out negative powers when the propeller is not rotating.
  double power = HP * hptoftlbssec;
  if (RPM <= 0.1) power = max(power, 0.0);
  Thruster->Calculate(power);
 
  RunPostFunctions();
}

◆ ExpSeek()

double ExpSeek	(	double *	var,
		double	target,
		double	accel,
		double	decel
	)

Definition at line 450 of file FGTurboProp.cpp.

{
// exponential delay instead of the linear delay used in Seek
  double v = *var;
  if (v > target) {
    v = (v - target) * exp ( -in.TotalDeltaT / decel_tau) + target;
  } else if (v < target) {
    v = (target - v) * (1 - exp ( -in.TotalDeltaT / accel_tau)) + v;
  }
  return v;
}

◆ GetCondition()

int GetCondition ( void ) const

inline

Definition at line 127 of file FGTurboProp.h.

127{ return Condition; }

◆ GetCutoff()

bool GetCutoff ( void ) const

inline

Definition at line 117 of file FGTurboProp.h.

117{ return Cutoff; }

◆ GetEngineLabels()

string GetEngineLabels ( const std::string & delimiter )

virtual

Implements FGEngine.

Definition at line 493 of file FGTurboProp.cpp.

{
  std::ostringstream buf;
 
  buf << Name << "_N1[" << EngineNumber << "]" << delimiter
      << Name << "_PwrAvail[" << EngineNumber << "]" << delimiter
      << Thruster->GetThrusterLabels(EngineNumber, delimiter);
 
  return buf.str();
}

◆ GetEngineValues()

string GetEngineValues ( const std::string & delimiter )

virtual

Implements FGEngine.

Definition at line 506 of file FGTurboProp.cpp.

{
  std::ostringstream buf;
 
  buf << N1 << delimiter
      << HP << delimiter
      << Thruster->GetThrusterValues(EngineNumber,delimiter);
 
  return buf.str();
}

◆ GetEngStarting()

double GetEngStarting ( void ) const

inline

Definition at line 121 of file FGTurboProp.h.

121{ return EngStarting; }

◆ GetGeneratorPower()

bool GetGeneratorPower ( void ) const

inline

Definition at line 126 of file FGTurboProp.h.

126{ return GeneratorPower; }

◆ GetIeluIntervent()

bool GetIeluIntervent ( void ) const

inline

Definition at line 109 of file FGTurboProp.h.

109{ return Ielu_intervent; }

◆ GetIeluThrottle()

double GetIeluThrottle ( void ) const

inline

Definition at line 108 of file FGTurboProp.h.

108{ return (ThrottlePos); }

◆ GetITT()

double GetITT ( void ) const

inline

Definition at line 120 of file FGTurboProp.h.

120{return Eng_ITT_degC;}

◆ GetN1()

double GetN1 ( void ) const

inline

Definition at line 119 of file FGTurboProp.h.

119{return N1;}

◆ getOilPressure_psi()

double getOilPressure_psi ( ) const

inline

Definition at line 123 of file FGTurboProp.h.

123{return OilPressure_psi;}

◆ getOilTemp_degF()

double getOilTemp_degF ( void )

inline

Definition at line 124 of file FGTurboProp.h.

124{return KelvinToFahrenheit(OilTemp_degK);}

JSBSim::FGJSBBase::KelvinToFahrenheit

static constexpr double KelvinToFahrenheit(double kelvin)

Converts from degrees Kelvin to degrees Fahrenheit.

Definition FGJSBBase.h:185

◆ GetPhase()

phaseType GetPhase ( void ) const

inline

Definition at line 114 of file FGTurboProp.h.

114{ return phase; }

◆ GetPowerAvailable()

double GetPowerAvailable ( void ) const

inline

Definition at line 106 of file FGTurboProp.h.

106{ return (HP * hptoftlbssec); }

◆ GetReversed()

bool GetReversed ( void ) const

inline

Definition at line 116 of file FGTurboProp.h.

116{ return Reversed; }

◆ GetRPM()

double GetRPM ( void ) const

inline

Definition at line 107 of file FGTurboProp.h.

107{ return RPM; }

◆ InitRunning()

int InitRunning ( void )

virtual

Reimplemented from FGEngine.

Definition at line 519 of file FGTurboProp.cpp.

{
  double dt = in.TotalDeltaT;
  in.TotalDeltaT = 0.0;
  Cutoff=false;
  Running=true;
  Calculate();
  in.TotalDeltaT = dt;
  return phase==tpRun;
}

◆ Seek()

double Seek	(	double *	var,
		double	target,
		double	accel,
		double	decel
	)

Definition at line 435 of file FGTurboProp.cpp.

{
  double v = *var;
  if (v > target) {
    v -= in.TotalDeltaT * decel;
    if (v < target) v = target;
  } else if (v < target) {
    v += in.TotalDeltaT * accel;
    if (v > target) v = target;
  }
  return v;
}

◆ SetCondition()

void SetCondition ( bool c )

inline

Definition at line 134 of file FGTurboProp.h.

134{ Condition=c; }

◆ SetCutoff()

void SetCutoff ( bool cutoff )

inline

Definition at line 131 of file FGTurboProp.h.

131{ Cutoff = cutoff; }

◆ SetGeneratorPower()

void SetGeneratorPower ( bool gp )

inline

Definition at line 133 of file FGTurboProp.h.

133{ GeneratorPower=gp; }

◆ SetPhase()

void SetPhase ( phaseType p )

inline

Definition at line 129 of file FGTurboProp.h.

129{ phase = p; }

◆ SetReverse()

void SetReverse ( bool reversed )

inline

Definition at line 130 of file FGTurboProp.h.

130{ Reversed = reversed; }

The documentation for this class was generated from the following files:

Detailed Description

Configuration parameters:

Public Types

Public Member Functions

Additional Inherited Members

Member Enumeration Documentation

◆ phaseType

Constructor & Destructor Documentation

◆ FGTurboProp()

Member Function Documentation

◆ CalcFuelNeed()

◆ Calculate()

◆ ExpSeek()

◆ GetCondition()

◆ GetCutoff()

◆ GetEngineLabels()

◆ GetEngineValues()

◆ GetEngStarting()

◆ GetGeneratorPower()

◆ GetIeluIntervent()

◆ GetIeluThrottle()

◆ GetITT()

◆ GetN1()

◆ getOilPressure_psi()

◆ getOilTemp_degF()

◆ GetPhase()

◆ GetPowerAvailable()

◆ GetReversed()

◆ GetRPM()

◆ InitRunning()

◆ Seek()

◆ SetCondition()

◆ SetCutoff()

◆ SetGeneratorPower()

◆ SetPhase()

◆ SetReverse()