Index: ControlMap.cpp =================================================================== RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/ControlMap.cpp,v retrieving revision 1.7 diff -p -u -r1.7 ControlMap.cpp --- ControlMap.cpp 17 Feb 2005 10:26:15 -0000 1.7 +++ ControlMap.cpp 22 Apr 2005 09:59:59 -0000 @@ -214,6 +214,8 @@ void ControlMap::applyControls(float dt) case REVERSE_THRUST: ((Jet*)obj)->setReverse(lval != 0); break; case BOOST: ((PistonEngine*)((Thruster*)obj)->getEngine())->setBoost(lval); + case CUTOUT: + ((PistonEngine*)((Thruster*)obj)->getEngine())->setCutout(lval); break; } } Index: ControlMap.hpp =================================================================== RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/ControlMap.hpp,v retrieving revision 1.6 diff -p -u -r1.6 ControlMap.hpp --- ControlMap.hpp 27 Dec 2004 13:18:29 -0000 1.6 +++ ControlMap.hpp 22 Apr 2005 10:02:01 -0000 @@ -15,7 +15,7 @@ public: INCIDENCE, FLAP0, FLAP1, SLAT, SPOILER, VECTOR, BOOST, CASTERING, PROPPITCH, PROPFEATHER, COLLECTIVE, CYCLICAIL, CYCLICELE, ROTORENGINEON, - REVERSE_THRUST }; + REVERSE_THRUST, CUTOUT }; enum { OPT_SPLIT = 0x01, OPT_INVERT = 0x02, Index: Engine.hpp =================================================================== RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/Engine.hpp,v retrieving revision 1.2 diff -p -u -r1.2 Engine.hpp --- Engine.hpp 1 May 2004 00:26:33 -0000 1.2 +++ Engine.hpp 22 Apr 2005 10:14:46 -0000 @@ -25,6 +25,7 @@ public: void setBoost(float boost) { _boost = boost; } void setFuelState(bool hasFuel) { _fuel = hasFuel; } void setRunning(bool r) { _running = r; } + void setCutout(bool cutout) { _cutout = cutout; } bool isRunning() { return _running; } virtual bool isCranking() { return false; } @@ -43,6 +44,7 @@ protected: float _boost; bool _fuel; bool _running; + bool _cutout; }; }; // namespace yasim Index: FGFDM.cpp =================================================================== RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/FGFDM.cpp,v retrieving revision 1.29 diff -p -u -r1.29 FGFDM.cpp --- FGFDM.cpp 17 Feb 2005 10:26:15 -0000 1.29 +++ FGFDM.cpp 18 May 2005 11:11:33 -0000 @@ -518,6 +518,11 @@ void FGFDM::setOutputProperties(float dt PistonEngine* pe = p->getEngine()->isPistonEngine(); node->setFloatValue("mp-osi", pe->getMP() * (1/INHG2PA)); node->setFloatValue("mp-inhg", pe->getMP() * (1/INHG2PA)); + node->setFloatValue("mp-pascals", pe->getMP() ); + node->setFloatValue("boost-pressure-inhg", + pe->getBoost() * (1/INHG2PA)); + node->setFloatValue("boost-pressure-psi-gauge", pe->getBoost() * 0.000145 + - 14.695949); node->setFloatValue("egt-degf", pe->getEGT() * K2DEGF + K2DEGFOFFSET); } else if(p->getEngine()->isTurbineEngine()) { @@ -667,9 +672,11 @@ void FGFDM::parsePistonEngine(XMLAttribu { float engP = attrf(a, "eng-power") * HP2W; float engS = attrf(a, "eng-rpm") * RPM2RAD; + - PistonEngine* eng = new PistonEngine(engP, engS); + PistonEngine* eng = new PistonEngine(engP, engS); + eng->setEngineSpeed(engS); if(a->hasAttribute("displacement")) eng->setDisplacement(attrf(a, "displacement") * CIN2CM); @@ -715,6 +722,7 @@ void FGFDM::parsePropeller(XMLAttributes float engP = attrf(a, "eng-power") * HP2W; float engS = attrf(a, "eng-rpm") * RPM2RAD; eng = new PistonEngine(engP, engS); + eng->setEngineSpeed(engS); if(a->hasAttribute("displacement")) eng->setDisplacement(attrf(a, "displacement") * CIN2CM); if(a->hasAttribute("compression")) @@ -825,6 +833,7 @@ int FGFDM::parseOutput(const char* name) if(eq(name, "CYCLICELE")) return ControlMap::CYCLICELE; if(eq(name, "ROTORENGINEON")) return ControlMap::ROTORENGINEON; if(eq(name, "REVERSE_THRUST")) return ControlMap::REVERSE_THRUST; + if(eq(name, "CUTOUT")) return ControlMap::CUTOUT; SG_LOG(SG_FLIGHT,SG_ALERT,"Unrecognized control type '" << name << "' in YASim aircraft description."); exit(1); Index: PistonEngine.cpp =================================================================== RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/PistonEngine.cpp,v retrieving revision 1.7 diff -p -u -r1.7 PistonEngine.cpp --- PistonEngine.cpp 1 May 2004 14:30:00 -0000 1.7 +++ PistonEngine.cpp 13 Jun 2005 12:25:10 -0000 @@ -1,7 +1,11 @@ +#ifdef HAVE_CONFIG_H +# include +#endif #include "Atmosphere.hpp" #include "Math.hpp" #include "PistonEngine.hpp" -namespace yasim { +#include +namespace yasim { const static float HP2W = 745.7f; const static float CIN2CM = 1.6387064e-5f; @@ -12,7 +16,7 @@ PistonEngine::PistonEngine(float power, _boost = 1; _running = false; _fuel = true; - + // Presume a BSFC (in lb/hour per HP) of 0.45. In SI that becomes // (2.2 lb/kg, 745.7 W/hp, 3600 sec/hour) 7.62e-08 kg/Ws. _f0 = power * 7.62e-08f; @@ -43,7 +47,7 @@ void PistonEngine::setTurboParams(float { _turbo = turbo; _maxMP = maxMP; - + // This changes the "sea level" manifold air density float P0 = Atmosphere::getStdPressure(0); float P = P0 * (1 + _boost * (_turbo - 1)); @@ -62,6 +66,11 @@ void PistonEngine::setCompression(float _compression = c; } +void PistonEngine::setEngineSpeed(float engineSpeed) +{ + _engineSpeed = engineSpeed; +} + float PistonEngine::getMaxPower() { return _power0; @@ -87,13 +96,21 @@ float PistonEngine::getMP() return _mp; } +float PistonEngine::getBoost() +{ + return _boostPressure; +} + float PistonEngine::getEGT() { return _egt; } + void PistonEngine::calc(float pressure, float temp, float speed) -{ +{ + + if(_magnetos == 0 || speed < 60*RPM2RADPS) _running = false; else if(_fuel == false) @@ -109,11 +126,43 @@ void PistonEngine::calc(float pressure, // power, so use 10% instead!) But we need to produce _zero_ // thrust at that setting, so hold onto the "output" value // separately. Ick. - _mp = pressure * (1 + _boost*(_turbo-1)); // turbocharger - float mp = _mp * (0.1f + 0.9f * _throttle); // throttle - _mp *= _throttle; - if(mp > _maxMP) mp = _maxMP; // wastegate + // Calculate the factor required to modify supercharger output for + // rpm. Assume that the normalized supercharger output ~= 1 when + // the engine is at the nominated peak-power rpm (normalised). + // A power equation of the form ((A*(B^x))*(x^C) has been + // derived empirically from some representative supercharger data. + // This provides near-linear output over the normal operating range, + // with fall-off in the over-speed situation. + float rpm_norm = (speed / _engineSpeed); + float A = 1.795206541; + float B = 0.55620178; + float C = 1.246708471; + float rpm_factor = (A * (pow(B,rpm_norm))) * (pow(rpm_norm,C)); + + // We need to adjust the minimum manifold pressure to get a + // reasonable idle speed. This is a hack. + float _minMP = (-0.008 * _turbo ) + 0.1; + + // max turbocharger output modified by rpm + _mp = pressure * (1 + (_boost * (_turbo-1) * rpm_factor)); + + // manifold pressure modified by throttle: only apply when the + // engine is running, otherwise we get odd results. + float mp = 0; + if (_running) { + mp = _mp * (_minMP + (1 -_minMP) * _throttle); + } else { + mp = _mp; + } + + // apply wastegate and boost control cutout + if(mp > _maxMP and _cutout == false) { + mp = _maxMP; + } + + _boostPressure = mp; + // Air entering the manifold does so rapidly, and thus the // pressure change can be assumed to be adiabatic. Calculate a // temperature change, and use that to get the density. Index: PistonEngine.hpp =================================================================== RCS file: /var/cvs/FlightGear-0.9/source/src/FDM/YASim/PistonEngine.hpp,v retrieving revision 1.4 diff -p -u -r1.4 PistonEngine.hpp --- PistonEngine.hpp 1 May 2004 14:30:00 -0000 1.4 +++ PistonEngine.hpp 25 Apr 2005 09:31:30 -0000 @@ -14,11 +14,13 @@ public: void setTurboParams(float mul, float maxMP); void setDisplacement(float d); void setCompression(float c); - + void setEngineSpeed(float engineSpeed); + bool isCranking(); float getMP(); float getEGT(); float getMaxPower(); // max sea-level power + float getBoost(); virtual void calc(float pressure, float temp, float speed); virtual float getTorque(); @@ -35,12 +37,19 @@ private: float _maxMP; // wastegate setting float _displacement; // piston stroke volume float _compression; // compression ratio (>1) - + float _engineSpeed; // + float _idleSpeed; // engine rmp at idle + // Runtime state/output: + float _boostPressure; float _mp; float _torque; float _fuelFlow; float _egt; + float _adjust; + float _step; + float _minMP; + }; }; // namespace yasim