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Sync. w. JSBSim CVS

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This commit is contained in:
ehofman 2009-04-13 11:47:57 +00:00 committed by Tim Moore
parent 71c9cb9f48
commit 720b6fa3f6
9 changed files with 321 additions and 153 deletions
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198
src/FDM/JSBSim/FGFDMExec.cpp
View file

@ -514,56 +514,170 @@ bool FGFDMExec::LoadModel(string model, bool addModelToPath)
document = LoadXMLDocument(aircraftCfgFileName); // "document" is a class member
if (document) {
ReadPrologue(document);
element = document->GetElement();
result = true;
while (element && result) {
string element_name = element->GetName();
if (element_name == "fileheader" ) result = ReadFileHeader(element);
else if (element_name == "slave") result = ReadSlave(element);
else if (element_name == "metrics") result = Aircraft->Load(element);
else if (element_name == "mass_balance") result = MassBalance->Load(element);
else if (element_name == "ground_reactions") result = GroundReactions->Load(element);
else if (element_name == "external_reactions") result = ExternalReactions->Load(element);
else if (element_name == "buoyant_forces") result = BuoyantForces->Load(element);
else if (element_name == "propulsion") result = Propulsion->Load(element);
else if (element_name == "system") result = FCS->Load(element,
FGFCS::stSystem);
else if (element_name == "autopilot") result = FCS->Load(element,
FGFCS::stAutoPilot);
else if (element_name == "flight_control") result = FCS->Load(element,
FGFCS::stFCS);
else if (element_name == "aerodynamics") result = Aerodynamics->Load(element);
else if (element_name == "input") result = Input->Load(element);
else if (element_name == "output") {
FGOutput* Output = new FGOutput(this);
Output->InitModel();
Schedule(Output, 1);
result = Output->Load(element);
Outputs.push_back(Output);
// Process the fileheader element in the aircraft config file. This element is OPTIONAL.
element = document->FindElement("fileheader");
if (element) {
result = ReadFileHeader(element);
if (!result) {
cerr << endl << "Aircraft fileheader element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the metrics element. This element is REQUIRED.
element = document->FindElement("metrics");
if (element) {
result = Aircraft->Load(element);
if (!result) {
cerr << endl << "Aircraft metrics element has problems in file " << aircraftCfgFileName << endl;
return result;
}
} else {
cerr << endl << "No metrics element was found in the aircraft config file." << endl;
return false;
}
// Process the mass_balance element. This element is REQUIRED.
element = document->FindElement("mass_balance");
if (element) {
result = MassBalance->Load(element);
if (!result) {
cerr << endl << "Aircraft mass_balance element has problems in file " << aircraftCfgFileName << endl;
return result;
}
} else {
cerr << endl << "No mass_balance element was found in the aircraft config file." << endl;
return false;
}
// Process the ground_reactions element. This element is REQUIRED.
element = document->FindElement("ground_reactions");
if (element) {
result = GroundReactions->Load(element);
if (!result) {
cerr << endl << "Aircraft ground_reactions element has problems in file " << aircraftCfgFileName << endl;
return result;
}
} else {
cerr << endl << "No ground_reactions element was found in the aircraft config file." << endl;
return false;
}
// Process the external_reactions element. This element is OPTIONAL.
element = document->FindElement("external_reactions");
if (element) {
result = ExternalReactions->Load(element);
if (!result) {
cerr << endl << "Aircraft external_reactions element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the buoyant_forces element. This element is OPTIONAL.
element = document->FindElement("buoyant_forces");
if (element) {
result = BuoyantForces->Load(element);
if (!result) {
cerr << endl << "Aircraft buoyant_forces element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the propulsion element. This element is OPTIONAL.
element = document->FindElement("propulsion");
if (element) {
result = Propulsion->Load(element);
if (!result) {
cerr << endl << "Aircraft propulsion element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the system element[s]. This element is OPTIONAL, and there may be more than one.
element = document->FindElement("system");
while (element) {
result = FCS->Load(element, FGFCS::stSystem);
if (!result) {
cerr << endl << "Aircraft system element has problems in file " << aircraftCfgFileName << endl;
return result;
}
element = document->FindNextElement("system");
}
// Process the autopilot element. This element is OPTIONAL.
element = document->FindElement("autopilot");
if (element) {
result = FCS->Load(element, FGFCS::stAutoPilot);
if (!result) {
cerr << endl << "Aircraft autopilot element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the flight_control element. This element is OPTIONAL.
element = document->FindElement("flight_control");
if (element) {
result = FCS->Load(element, FGFCS::stFCS);
if (!result) {
cerr << endl << "Aircraft flight_control element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the aerodynamics element. This element is OPTIONAL, but almost always expected.
element = document->FindElement("aerodynamics");
if (element) {
result = Aerodynamics->Load(element);
if (!result) {
cerr << endl << "Aircraft aerodynamics element has problems in file " << aircraftCfgFileName << endl;
return result;
}
} else {
cerr << endl << "No expected aerodynamics element was found in the aircraft config file." << endl;
}
// Process the input element. This element is OPTIONAL.
element = document->FindElement("input");
if (element) {
result = Input->Load(element);
if (!result) {
cerr << endl << "Aircraft input element has problems in file " << aircraftCfgFileName << endl;
return result;
}
}
// Process the output element[s]. This element is OPTIONAL, and there may be more than one.
element = document->FindElement("output");
while (element) {
FGOutput* Output = new FGOutput(this);
Output->InitModel();
Schedule(Output, 1);
result = Output->Load(element);
Outputs.push_back(Output);
if (!result) {
cerr << endl << "Aircraft output element has problems in file " << aircraftCfgFileName << endl;
return result;
}
element = document->FindNextElement("output");
}
// Lastly, process the slave element. This element is OPTIONAL - and NOT YET SUPPORTED.
element = document->FindElement("slave");
if (element) {
result = ReadSlave(element);
if (!result) {
cerr << endl << "Aircraft slave element has problems in file " << aircraftCfgFileName << endl;
return result;
}
else {
cerr << "Found unexpected subsystem: " << element_name << ", exiting." << endl;
result = false;
break;
}
element = document->GetNextElement();
}
} else {
cerr << fgred
<< " JSBSim failed to load aircraft model."
<< fgdef << endl;
return false;
}
if (result) {
modelLoaded = true;
Debug(3);
} else {
cerr << fgred
<< " JSBSim failed to load properly."
<< " JSBSim failed to open the configuration file: " << aircraftCfgFileName
<< fgdef << endl;
return false;
}
struct PropertyCatalogStructure masterPCS;

17
src/FDM/JSBSim/JSBSim.cxx
View file

@ -150,9 +150,6 @@ FGJSBsim::FGJSBsim( double dt )
// file on each FlightGear reset.
fgGetNode("/fdm/jsbsim/simulation/write-state-file")->untie();
fgGetNode("/fdm/jsbsim/simulation")->removeChild("write-state-file", false);
// Prevent nuking of the state on JSBSim recreation after FlightGear reset.
fgGetNode("/fdm/jsbsim/simulation/reset")->untie();
fgGetNode("/fdm/jsbsim/simulation")->removeChild("reset", false);
// end ugly hack
// Register ground callback.
@ -328,9 +325,9 @@ void FGJSBsim::init()
Atmosphere->UseInternal();
}
fgic->SetVNorthFpsIC( wind_from_north->getDoubleValue() );
fgic->SetVEastFpsIC( wind_from_east->getDoubleValue() );
fgic->SetVDownFpsIC( wind_from_down->getDoubleValue() );
fgic->SetVNorthFpsIC( -wind_from_north->getDoubleValue() );
fgic->SetVEastFpsIC( -wind_from_east->getDoubleValue() );
fgic->SetVDownFpsIC( -wind_from_down->getDoubleValue() );
//Atmosphere->SetExTemperature(get_Static_temperature());
//Atmosphere->SetExPressure(get_Static_pressure());
@ -625,9 +622,9 @@ bool FGJSBsim::copy_to_JSBsim()
tmp = turbulence_rate->getDoubleValue();
//Atmosphere->SetTurbRate(tmp);
Atmosphere->SetWindNED( wind_from_north->getDoubleValue(),
wind_from_east->getDoubleValue(),
wind_from_down->getDoubleValue() );
Atmosphere->SetWindNED( -wind_from_north->getDoubleValue(),
-wind_from_east->getDoubleValue(),
-wind_from_down->getDoubleValue() );
// SG_LOG(SG_FLIGHT,SG_INFO, "Wind NED: "
// << get_V_north_airmass() << ", "
// << get_V_east_airmass() << ", "
@ -1100,6 +1097,7 @@ void FGJSBsim::init_gear(void )
node->setDoubleValue("yoffset-in", gear->GetBodyLocation()(2));
node->setDoubleValue("zoffset-in", gear->GetBodyLocation()(3));
node->setBoolValue("wow", gear->GetWOW());
node->setDoubleValue("rollspeed-ms", gear->GetWheelRollVel()*0.3043);
node->setBoolValue("has-brake", gear->GetBrakeGroup() > 0);
node->setDoubleValue("position-norm", gear->GetGearUnitPos());
node->setDoubleValue("tire-pressure-norm", gear->GetTirePressure());
@ -1118,6 +1116,7 @@ void FGJSBsim::update_gear(void)
FGLGear *gear = gr->GetGearUnit(i);
SGPropertyNode * node = fgGetNode("gear/gear", i, true);
node->getChild("wow", 0, true)->setBoolValue( gear->GetWOW());
node->getChild("rollspeed-ms", 0, true)->setDoubleValue(gear->GetWheelRollVel()*0.3043);
node->getChild("position-norm", 0, true)->setDoubleValue(gear->GetGearUnitPos());
gear->SetTirePressure(node->getDoubleValue("tire-pressure-norm"));
node->setDoubleValue("compression-norm", gear->GetCompLen());

4
src/FDM/JSBSim/initialization/FGInitialCondition.cpp
View file

@ -69,7 +69,9 @@ FGInitialCondition::FGInitialCondition(FGFDMExec *FDMExec) : fdmex(FDMExec)
fdmex->GetPropagate()->Seth(altitude);
fdmex->GetAtmosphere()->Run();
PropertyManager=fdmex->GetPropertyManager();
Constructing = true;
bind();
Constructing = false;
} else {
cout << "FGInitialCondition: This class requires a pointer to a valid FGFDMExec object" << endl;
}
@ -156,6 +158,8 @@ void FGInitialCondition::InitializeIC(void)
void FGInitialCondition::WriteStateFile(int num)
{
if (Constructing) return;
string filename = fdmex->GetFullAircraftPath();
if (filename.empty())

1
src/FDM/JSBSim/initialization/FGInitialCondition.h
View file

@ -644,6 +644,7 @@ private:
FGFDMExec *fdmex;
FGPropertyManager *PropertyManager;
bool Constructing;
bool getAlpha(void);
bool getTheta(void);
bool getMachFromVcas(double *Mach,double vcas);

3
src/FDM/JSBSim/models/FGLGear.cpp
View file

@ -340,6 +340,9 @@ FGColumnVector3& FGLGear::Force(void)
WOW = false;
compressLength = 0.0;
// No wheel conditons
RollingWhlVel = SideWhlVel = WheelSlip = 0.0;
// Return to neutral position between 1.0 and 0.8 gear pos.
SteerAngle *= max(GetGearUnitPos()-0.8, 0.0)/0.2;

214
src/FDM/JSBSim/models/propulsion/FGPiston.cpp
View file

@ -71,8 +71,9 @@ FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number)
dt = State->Getdt();
// These items are read from the configuration file
// Defaults are from a Lycoming O-360, more or less
Cycles = 2;
Cycles = 4;
IdleRPM = 600;
MaxRPM = 2800;
Displacement = 360;
@ -80,10 +81,12 @@ FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number)
MaxHP = 200;
MinManifoldPressure_inHg = 6.5;
MaxManifoldPressure_inHg = 28.5;
BSFC = -1;
// Initialisation
volumetric_efficiency = 0.8; // Actually f(speed, load) but this will get us running
ISFC = -1;
volumetric_efficiency = -0.1;
Bore = 5.125;
Stroke = 4.375;
Cylinders = 4;
CompressionRatio = 8.5;
// These are internal program variables
@ -173,9 +176,17 @@ FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number)
if (el->FindElement("minthrottle"))
MinThrottle = el->FindElementValueAsNumber("minthrottle");
if (el->FindElement("bsfc"))
BSFC = el->FindElementValueAsNumberConvertTo("bsfc", "LBS/HP*HR");
ISFC = el->FindElementValueAsNumberConvertTo("bsfc", "LBS/HP*HR");
if (el->FindElement("volumetric-efficiency"))
volumetric_efficiency = el->FindElementValueAsNumber("volumetric-efficiency");
if (el->FindElement("compression-ratio"))
CompressionRatio = el->FindElementValueAsNumber("compression-ratio");
if (el->FindElement("bore"))
Bore = el->FindElementValueAsNumberConvertTo("bore","IN");
if (el->FindElement("stroke"))
Stroke = el->FindElementValueAsNumberConvertTo("stroke","IN");
if (el->FindElement("stroke"))
Cylinders = el->FindElementValueAsNumber("cylinders");
if (el->FindElement("numboostspeeds")) { // Turbo- and super-charging parameters
BoostSpeeds = (int)el->FindElementValueAsNumber("numboostspeeds");
if (el->FindElement("boostoverride"))
@ -208,30 +219,42 @@ FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number)
RatedAltitude[2] = el->FindElementValueAsNumberConvertTo("ratedaltitude3", "FT");
}
MaxManifoldPressure_Percent = MaxManifoldPressure_inHg / 29.92;
// Create a BSFC to match the engine if not provided
if (BSFC < 0) {
BSFC = ( Displacement * MaxRPM * volumetric_efficiency ) / (9411 * MaxHP);
BSFC *= (MaxManifoldPressure_Percent * MaxManifoldPressure_Percent * MaxManifoldPressure_Percent);
StarterHP = sqrt(MaxHP) * 0.4;
displacement_SI = Displacement * in3tom3;
// Create IFSC and VE to match the engine if not provided
int calculated_ve=0;
if (volumetric_efficiency < 0) {
volumetric_efficiency = MaxManifoldPressure_inHg / 29.92;
calculated_ve=1;
}
if (ISFC < 0) {
double pmep = MaxManifoldPressure_inHg > 29.92 ? 0 : 29.92 - MaxManifoldPressure_inHg;
pmep *= inhgtopa;
double fmep = (18400 * (2*(Stroke/12)*(MaxRPM/60)) * fttom + 46500)/2;
double hp_loss = ((pmep + fmep) * displacement_SI * MaxRPM)/(Cycles*22371);
ISFC = ( Displacement * MaxRPM * volumetric_efficiency ) / (9411 * (MaxHP+hp_loss));
// cout <<"FMEP: "<< fmep <<" PMEP: "<< pmep << " hp_loss: " <<hp_loss <<endl;
}
if ( MaxManifoldPressure_inHg > 29.9 ) { // Don't allow boosting with a bogus number
MaxManifoldPressure_inHg = 29.9;
MaxManifoldPressure_Percent = MaxManifoldPressure_inHg / 29.92;
if (calculated_ve) volumetric_efficiency = 1.0;
}
minMAP = MinManifoldPressure_inHg * inhgtopa; // inHg to Pa
maxMAP = MaxManifoldPressure_inHg * inhgtopa;
string property_name, base_property_name;
base_property_name = CreateIndexedPropertyName("propulsion/engine", EngineNumber);
property_name = base_property_name + "/power-hp";
PropertyManager->Tie(property_name, &HP);
property_name = base_property_name + "/bsfc-lbs_hphr";
PropertyManager->Tie(property_name, &BSFC);
PropertyManager->Tie(property_name, &ISFC);
property_name = base_property_name + "/volumetric-efficiency";
PropertyManager->Tie(property_name, &volumetric_efficiency);
property_name = base_property_name + "/map-pa";
PropertyManager->Tie(property_name, &MAP);
property_name = base_property_name + "/map-inhg";
PropertyManager->Tie(property_name, &ManifoldPressure_inHg);
minMAP = MinManifoldPressure_inHg * inhgtopa; // inHg to Pa
maxMAP = MaxManifoldPressure_inHg * inhgtopa;
StarterHP = sqrt(MaxHP) * 0.4;
// Set up and sanity-check the turbo/supercharging configuration based on the input values.
if (TakeoffBoost > RatedBoost[0]) bTakeoffBoost = true;
@ -279,9 +302,6 @@ FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number)
BoostSpeed = 0;
}
bBoostOverride = (BoostOverride == 1 ? true : false);
if (MinThrottle < 0.12) MinThrottle = 0.12; //MinThrottle is limited to 0.12 to prevent the
// throttle area equation from going negative
// 0.12 is 1% of maximum area
Debug(0); // Call Debug() routine from constructor if needed
}
@ -319,7 +339,7 @@ double FGPiston::Calculate(void)
if (FuelFlow_gph > 0.0) ConsumeFuel();
Throttle = FCS->GetThrottlePos(EngineNumber);
// calculate the throttle plate angle. 1 unit is pi/2 radians.
// calculate the throttle plate angle. 1 unit is approx pi/2 radians.
ThrottleAngle = MinThrottle+((MaxThrottle-MinThrottle)*Throttle );
Mixture = FCS->GetMixturePos(EngineNumber);
@ -328,10 +348,10 @@ double FGPiston::Calculate(void)
//
p_amb = Atmosphere->GetPressure() * psftopa;
p_amb_sea_level = Atmosphere->GetPressureSL() * psftopa;
T_amb = RankineToKelvin(Atmosphere->GetTemperature());
RPM = Thruster->GetRPM() * Thruster->GetGearRatio();
MeanPistonSpeed_fps = ( RPM * Stroke) / (360); // AKA 2 * (RPM/60) * ( Stroke / 12) or 2NS
IAS = Auxiliary->GetVcalibratedKTS();
@ -349,7 +369,7 @@ double FGPiston::Calculate(void)
// Running = false;
doEnginePower();
if (HP < 0.1250) Running = false;
if (IndicatedHorsePower < 0.1250) Running = false;
doEGT();
doCHT();
@ -489,57 +509,62 @@ void FGPiston::doBoostControl(void)
* from the throttle position, turbo/supercharger boost control
* system, engine speed and local ambient air density.
*
* Inputs: p_amb, Throttle, MaxManifoldPressure_Percent, ThrottleAngle
* RPM, MaxRPM
* Inputs: p_amb, Throttle, ThrottleAngle,
* MeanPistonSpeed_fps, dt
*
* Outputs: MAP, ManifoldPressure_inHg
*/
void FGPiston::doMAP(void)
{
// estimate throttle plate area. This maps 0.2 -> 0.1 for historical performance reasons
double throttle_area = ThrottleAngle * 1.125 - 0.125;
map_coefficient = pow ((throttle_area * MaxManifoldPressure_Percent),RPM/MaxRPM);
MAP = p_amb * map_coefficient;
// estimate throttle plate area.
double throttle_area = ThrottleAngle*ThrottleAngle;
// Internal Combustion Engine in Theory and Practice, Volume 2. Charles Fayette Taylor. Revised Edition, 1985 fig 6-13
double map_coefficient = 1-((MeanPistonSpeed_fps*MeanPistonSpeed_fps)/(24978*throttle_area));
if(Boosted) {
// If takeoff boost is fitted, we currently assume the following throttle map:
// (In throttle % - actual input is 0 -> 1)
// 99 / 100 - Takeoff boost
// 96 / 97 / 98 - Rated boost
// 0 - 95 - Idle to Rated boost (MinManifoldPressure to MaxManifoldPressure)
// In real life, most planes would be fitted with a mechanical 'gate' between
// the rated boost and takeoff boost positions.
double T = Throttle; // processed throttle value.
bool bTakeoffPos = false;
if(bTakeoffBoost) {
if(Throttle > 0.98) {
//cout << "Takeoff Boost!!!!\n";
bTakeoffPos = true;
} else if(Throttle <= 0.95) {
bTakeoffPos = false;
T *= 1.0 / 0.95;
} else {
bTakeoffPos = false;
//cout << "Rated Boost!!\n";
T = 1.0;
}
}
// Boost the manifold pressure.
double boost_factor = BoostMul[BoostSpeed] * map_coefficient * RPM/RatedRPM[BoostSpeed];
if (boost_factor < 1.0) boost_factor = 1.0; // boost will never reduce the MAP
MAP *= boost_factor;
// Now clip the manifold pressure to BCV or Wastegate setting.
if(bTakeoffPos) {
if(MAP > TakeoffMAP[BoostSpeed]) {
MAP = TakeoffMAP[BoostSpeed];
}
if ( map_coefficient < 0.1 ) map_coefficient = 0.1;
// map_coefficient = pow ((throttle_area * MaxManifoldPressure_Percent),RPM/MaxRPM);
// Add a one second lag to manifold pressure changes
double dMAP = (MAP - p_amb * map_coefficient) * dt;
MAP -=dMAP;
// Find the mean effective pressure required to achieve this manifold pressure
// Doing this before boost so boost doesn't add horsepower to the engine.
// A better method would be deterimining the HP consumed by the supercharger
PMEP = MAP - p_amb; // Fixme: p_amb should be exhaust manifold pressure
if (Boosted) {
// If takeoff boost is fitted, we currently assume the following throttle map:
// (In throttle % - actual input is 0 -> 1)
// 99 / 100 - Takeoff boost
// 96 / 97 / 98 - Rated boost
// 0 - 95 - Idle to Rated boost (MinManifoldPressure to MaxManifoldPressure)
// In real life, most planes would be fitted with a mechanical 'gate' between
// the rated boost and takeoff boost positions.
bool bTakeoffPos = false;
if (bTakeoffBoost) {
if (Throttle > 0.98) {
bTakeoffPos = true;
} else if(Throttle <= 0.95) {
bTakeoffPos = false;
} else {
if(MAP > RatedMAP[BoostSpeed]) {
MAP = RatedMAP[BoostSpeed];
}
bTakeoffPos = false;
}
}
// Boost the manifold pressure.
double boost_factor = BoostMul[BoostSpeed] * map_coefficient * RPM/RatedRPM[BoostSpeed];
if (boost_factor < 1.0) boost_factor = 1.0; // boost will never reduce the MAP
MAP *= boost_factor;
// Now clip the manifold pressure to BCV or Wastegate setting.
if (bTakeoffPos) {
if (MAP > TakeoffMAP[BoostSpeed]) MAP = TakeoffMAP[BoostSpeed];
} else {
if (MAP > RatedMAP[BoostSpeed]) MAP = RatedMAP[BoostSpeed];
}
}
// And set the value in American units as well
ManifoldPressure_inHg = MAP / inhgtopa;
@ -561,20 +586,24 @@ void FGPiston::doMAP(void)
void FGPiston::doAirFlow(void)
{
double gamma = 1.4; // specific heat constants
// loss of volumentric efficiency due to difference between MAP and exhaust pressure
double ve =((gamma-1)/gamma)+( CompressionRatio -(p_amb/MAP))/(gamma*( CompressionRatio - 1));
rho_air = p_amb / (R_air * T_amb);
double displacement_SI = Displacement * in3tom3;
double swept_volume = (displacement_SI * (RPM/60)) / 2;
double v_dot_air = swept_volume * volumetric_efficiency * map_coefficient;
double v_dot_air = swept_volume * volumetric_efficiency *ve;
double rho_air_manifold = MAP / (R_air * T_amb);
m_dot_air = v_dot_air * rho_air_manifold;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
/**
* Calculate the fuel flow into the engine.
*
* Inputs: Mixture, thi_sea_level, p_amb_sea_level, p_amb, m_dot_air
* Inputs: Mixture, thi_sea_level, p_amb, m_dot_air
*
* Outputs: equivalence_ratio, m_dot_fuel
*/
@ -601,49 +630,53 @@ void FGPiston::doFuelFlow(void)
* 200HP.
*
* Inputs: ManifoldPressure_inHg, p_amb, RPM, T_amb,
* Mixture_Efficiency_Correlation, Cycles, MaxHP
* Mixture_Efficiency_Correlation, Cycles, MaxHP, PMEP,
*
* Outputs: Percentage_Power, HP
* Outputs: PctPower, HP
*/
void FGPiston::doEnginePower(void)
{
IndicatedHorsePower = 0;
FMEP = 0;
if (Running) {
// FIXME: this needs to be generalized
double ME, friction, percent_RPM, power; // Convienience term for use in the calculations
double ME, percent_RPM, power; // Convienience term for use in the calculations
ME = Mixture_Efficiency_Correlation->GetValue(m_dot_fuel/m_dot_air);
percent_RPM = RPM/MaxRPM;
friction = 1 - (percent_RPM * percent_RPM * percent_RPM * percent_RPM/10);
if (friction < 0 ) friction = 0;
power = friction;
// Guestimate engine friction as a percentage of rated HP + a percentage of rpm + a percentage of Indicted HP
// friction = 1 - (percent_RPM * percent_RPM * percent_RPM/10);
FMEP = (-18400 * MeanPistonSpeed_fps * fttom - 46500);
power = 1;
if ( Magnetos != 3 ) power *= SparkFailDrop;
HP = (FuelFlow_gph * 6.0 / BSFC )* ME * map_coefficient * power;
IndicatedHorsePower = (FuelFlow_pph / ISFC )* ME * power;
} else {
// Power output when the engine is not running
if (Cranking) {
if (RPM < 10) {
HP = StarterHP;
IndicatedHorsePower = StarterHP;
} else if (RPM < IdleRPM*0.8) {
HP = StarterHP + ((IdleRPM*0.8 - RPM) / 8.0);
IndicatedHorsePower = StarterHP + ((IdleRPM*0.8 - RPM) / 8.0);
// This is a guess - would be nice to find a proper starter moter torque curve
} else {
HP = StarterHP;
IndicatedHorsePower = StarterHP;
}
} else {
// Quick hack until we port the FMEP stuff
if (RPM > 0.0)
HP = -1.5;
else
HP = 0.0;
}
}
Percentage_Power = HP / MaxHP ;
// Constant is (1/2) * 60 * 745.7
// (1/2) convert cycles, 60 minutes to seconds, 745.7 watts to hp.
double pumping_hp = ((PMEP + FMEP) * displacement_SI * RPM)/(Cycles*22371);
HP = IndicatedHorsePower + pumping_hp - 1.5; //FIXME 1.5 static friction should depend on oil temp and configuration
// cout << "pumping_hp " <<pumping_hp << FMEP << PMEP <<endl;
PctPower = HP / MaxHP ;
// cout << "Power = " << HP << " RPM = " << RPM << " Running = " << Running << " Cranking = " << Cranking << endl;
}
@ -652,7 +685,7 @@ void FGPiston::doEnginePower(void)
* Calculate the exhaust gas temperature.
*
* Inputs: equivalence_ratio, m_dot_fuel, calorific_value_fuel,
* Cp_air, m_dot_air, Cp_fuel, m_dot_fuel, T_amb, Percentage_Power
* Cp_air, m_dot_air, Cp_fuel, m_dot_fuel, T_amb, PctPower
*
* Outputs: combustion_efficiency, ExhaustGasTemp_degK
*/
@ -671,7 +704,7 @@ void FGPiston::doEGT(void)
heat_capacity_exhaust = (Cp_air * m_dot_air) + (Cp_fuel * m_dot_fuel);
delta_T_exhaust = enthalpy_exhaust / heat_capacity_exhaust;
ExhaustGasTemp_degK = T_amb + delta_T_exhaust;
ExhaustGasTemp_degK *= 0.444 + ((0.544 - 0.444) * Percentage_Power);
ExhaustGasTemp_degK *= 0.444 + ((0.544 - 0.444) * PctPower);
} else { // Drop towards ambient - guess an appropriate time constant for now
combustion_efficiency = 0;
dEGTdt = (RankineToKelvin(Atmosphere->GetTemperature()) - ExhaustGasTemp_degK) / 100.0;
@ -835,14 +868,19 @@ void FGPiston::Debug(int from)
cout << " MinManifoldPressure: " << MinManifoldPressure_inHg << endl;
cout << " MaxManifoldPressure: " << MaxManifoldPressure_inHg << endl;
cout << " MinMaP (Pa): " << minMAP << endl;
cout << " MaxMaP (Pa): " << maxMAP << endl;
cout << " MaxMaP (Pa): " << maxMAP << endl;
cout << " Displacement: " << Displacement << endl;
cout << " Bore: " << Bore << endl;
cout << " Stroke: " << Stroke << endl;
cout << " Cylinders: " << Cylinders << endl;
cout << " Compression Ratio: " << CompressionRatio << endl;
cout << " MaxHP: " << MaxHP << endl;
cout << " Cycles: " << Cycles << endl;
cout << " IdleRPM: " << IdleRPM << endl;
cout << " MaxThrottle: " << MaxThrottle << endl;
cout << " MinThrottle: " << MinThrottle << endl;
cout << " BSFC: " << BSFC << endl;
cout << " ISFC: " << ISFC << endl;
cout << " Volumentric Efficiency: " << volumetric_efficiency << endl;
cout << endl;
cout << " Combustion Efficiency table:" << endl;

25
src/FDM/JSBSim/models/propulsion/FGPiston.h
View file

@ -67,8 +67,12 @@ CLASS DOCUMENTATION
@code
<piston_engine name="{string}">
<minmp unit="{INHG | PA | ATM}"> {number} </minmp> <!-- Depricated -->
<maxmp unit="{INHG | PA | ATM}"> {number} </maxmp> <!-- Depricated -->
<maxmp unit="{INHG | PA | ATM}"> {number} </maxmp>
<displacement unit="{IN3 | LTR | CC}"> {number} </displacement>
<bore unit="{IN | M}"> {number} </bore>
<stroke unit="{IN | M}"> {number} </stroke>
<cylinders> {number} </cylinders>
<compression-ratio> {number} </compression-ratio>
<sparkfaildrop> {number} </sparkfaildrop>
<maxhp unit="{HP | WATTS}"> {number} </maxhp>
<cycles> {number} </cycles>
@ -76,9 +80,9 @@ CLASS DOCUMENTATION
<maxrpm> {number} </maxrpm>
<maxthrottle> {number} </maxthrottle>
<minthrottle> {number} </minthrottle>
<numboostspeeds> {number} </numboostspeeds>
<bsfc unit="{LBS/HP*HR | "KG/KW*HR"}"> {number} </bsft>
<volumetric_efficiency> {number} </volumetric_efficiency>
<numboostspeeds> {number} </numboostspeeds>
<boostoverride> {0 | 1} </boostoverride>
<ratedboost1 unit="{INHG | PA | ATM}"> {number} </ratedboost1>
<ratedpower1 unit="{HP | WATTS}"> {number} </ratedpower1>
@ -210,7 +214,9 @@ protected:
private:
int crank_counter;
double BrakeHorsePower;
double IndicatedHorsePower;
double PMEP;
double FMEP;
double SpeedSlope;
double SpeedIntercept;
double AltitudeSlope;
@ -243,7 +249,6 @@ private:
const double Cp_fuel; // J/KgK
FGTable *Lookup_Combustion_Efficiency;
FGTable *Power_Mixture_Correlation;
FGTable *Mixture_Efficiency_Correlation;
//
@ -253,11 +258,17 @@ private:
double MaxManifoldPressure_inHg; // Inches Hg
double MaxManifoldPressure_Percent; // MaxManifoldPressure / 29.92
double Displacement; // cubic inches
double displacement_SI; // cubic meters
double MaxHP; // horsepower
double SparkFailDrop; // drop of power due to spark failure
double Cycles; // cycles/power stroke
double IdleRPM; // revolutions per minute
double MaxRPM; // revolutions per minute
double Bore; // inches
double Stroke; // inches
double Cylinders; // number
double CompressionRatio; // number
double StarterHP; // initial horsepower of starter motor
int BoostSpeeds; // Number of super/turbocharger boost speeds - zero implies no turbo/supercharging.
int BoostSpeed; // The current boost-speed (zero-based).
@ -284,13 +295,12 @@ private:
double minMAP; // Pa
double maxMAP; // Pa
double MAP; // Pa
double BSFC; // brake specific fuel consumption [lbs/horsepower*hour
double ISFC; // Indicated specific fuel consumption [lbs/horsepower*hour
//
// Inputs (in addition to those in FGEngine).
//
double p_amb; // Pascals
double p_amb_sea_level; // Pascals
double T_amb; // degrees Kelvin
double RPM; // revolutions per minute
double IAS; // knots
@ -298,7 +308,6 @@ private:
bool Magneto_Right;
int Magnetos;
//
// Outputs (in addition to those in FGEngine).
//
@ -308,7 +317,6 @@ private:
double m_dot_air;
double equivalence_ratio;
double m_dot_fuel;
double Percentage_Power;
double HP;
double combustion_efficiency;
double ExhaustGasTemp_degK;
@ -317,6 +325,7 @@ private:
double CylinderHeadTemp_degK;
double OilPressure_psi;
double OilTemp_degK;
double MeanPistonSpeed_fps;
void Debug(int from);
};

8
src/FDM/JSBSim/models/propulsion/FGTank.cpp
View file

@ -37,6 +37,7 @@ INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#include "FGTank.h"
#include <models/FGAuxiliary.h>
using std::cerr;
using std::endl;
@ -52,7 +53,7 @@ CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
FGTank::FGTank(FGFDMExec* exec, Element* el, int tank_number)
: TankNumber(tank_number)
: TankNumber(tank_number), Exec(exec)
{
string token;
Element* element;
@ -60,9 +61,8 @@ FGTank::FGTank(FGFDMExec* exec, Element* el, int tank_number)
Area = 1.0;
Temperature = -9999.0;
Ixx = Iyy = Izz = 0.0;
Auxiliary = exec->GetAuxiliary();
Radius = Capacity = Contents = Standpipe = Length = InnerRadius = 0.0;
PropertyManager = exec->GetPropertyManager();
PropertyManager = Exec->GetPropertyManager();
vXYZ.InitMatrix();
vXYZ_drain.InitMatrix();
@ -245,7 +245,7 @@ double FGTank::Calculate(double dt)
if (Temperature == -9999.0) return 0.0;
double HeatCapacity = 900.0; // Joules/lbm/C
double TempFlowFactor = 1.115; // Watts/sqft/C
double TAT = Auxiliary->GetTAT_C();
double TAT = Exec->GetAuxiliary()->GetTAT_C();
double Tdiff = TAT - Temperature;
double dTemp = 0.0; // Temp change due to one surface
if (fabs(Tdiff) > 0.1) {

4
src/FDM/JSBSim/models/propulsion/FGTank.h
View file

@ -44,10 +44,10 @@ SENTRY
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#include "FGFDMExec.h"
#include <FGJSBBase.h>
#include <input_output/FGXMLElement.h>
#include <math/FGColumnVector3.h>
#include <models/FGAuxiliary.h>
#include <string>
using std::string;
@ -281,7 +281,7 @@ private:
double Temperature, InitialTemperature;
double Standpipe, InitialStandpipe;
bool Selected;
FGAuxiliary* Auxiliary;
FGFDMExec* Exec;
FGPropertyManager* PropertyManager;
void CalculateInertias(void);
void Debug(int from);