JSBSim Flight Dynamics Model 1.2.2 (22 Mar 2025)
An Open Source Flight Dynamics and Control Software Library in C++
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FGPiston.cpp
1/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2
3 Module: FGPiston.cpp
4 Author: Jon S. Berndt, JSBSim framework
5 Dave Luff, Piston engine model
6 Ronald Jensen, Piston engine model
7 Date started: 09/12/2000
8 Purpose: This module models a Piston engine
9
10 ------------- Copyright (C) 2000 Jon S. Berndt (jon@jsbsim.org) --------------
11
12 This program is free software; you can redistribute it and/or modify it under
13 the terms of the GNU Lesser General Public License as published by the Free Software
14 Foundation; either version 2 of the License, or (at your option) any later
15 version.
16
17 This program is distributed in the hope that it will be useful, but WITHOUT
18 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
19 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
20 details.
21
22 You should have received a copy of the GNU Lesser General Public License along with
23 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
24 Place - Suite 330, Boston, MA 02111-1307, USA.
25
26 Further information about the GNU Lesser General Public License can also be found on
27 the world wide web at http://www.gnu.org.
28
29FUNCTIONAL DESCRIPTION
30--------------------------------------------------------------------------------
31
32This class descends from the FGEngine class and models a Piston engine based on
33parameters given in the engine config file for this class
34
35HISTORY
36--------------------------------------------------------------------------------
3709/12/2000 JSB Created
38
39%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
40INCLUDES
41%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
42
43#include <iostream>
44#include <sstream>
45
46#include "FGFDMExec.h"
47#include "FGPiston.h"
48#include "FGPropeller.h"
49#include "input_output/FGXMLElement.h"
50
51using namespace std;
52
53namespace JSBSim {
54
55/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
56CLASS IMPLEMENTATION
57%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
58
59FGPiston::FGPiston(FGFDMExec* exec, Element* el, int engine_number, struct Inputs& input)
60 : FGEngine(engine_number, input),
61 R_air(287.3), // Gas constant for air J/Kg/K
62 calorific_value_fuel(47.3e6), // J/Kg
63 Cp_air(1005), // Specific heat (constant pressure) J/Kg/K
64 Cp_fuel(1700),
65 standard_pressure(101320.73)
66{
67 Load(exec, el);
68
69 Element *table_element;
70 auto PropertyManager = exec->GetPropertyManager();
71
72 // Defaults and initializations
73
74 Type = etPiston;
75
76 // These items are read from the configuration file
77 // Defaults are from a Lycoming O-360, more or less
78
79 Cycles = 4;
80 IdleRPM = 600;
81 MaxRPM = 2800;
82 Displacement = 360;
83 SparkFailDrop = 1.0;
84 MaxHP = 200;
85 MinManifoldPressure_inHg = 6.5;
86 MaxManifoldPressure_inHg = 28.5;
87 ManifoldPressureLag=1.0;
88 ISFC = -1;
89 volumetric_efficiency = 0.85;
90 Bore = 5.125;
91 Stroke = 4.375;
92 Cylinders = 4;
93 CylinderHeadMass = 2; //kg
94 CompressionRatio = 8.5;
95 Z_airbox = -999;
96 Ram_Air_Factor = 1;
97 PeakMeanPistonSpeed_fps = 100;
98 FMEPDynamic= 18400;
99 FMEPStatic = 46500;
100 Cooling_Factor = 0.5144444;
101 StaticFriction_HP = 1.5;
102 StarterGain = 1.;
103 StarterTorque = -1.;
104 StarterRPM = -1.;
105
106 // These are internal program variables
107
108 Lookup_Combustion_Efficiency = 0;
109 Mixture_Efficiency_Correlation = 0;
110 crank_counter = 0;
111 Magnetos = 0;
112 minMAP = 21950;
113 maxMAP = 96250;
114
115 ResetToIC();
116
117 // Supercharging
118 BoostSpeeds = 0; // Default to no supercharging
119 BoostSpeed = 0;
120 Boosted = false;
121 BoostOverride = 0;
122 BoostManual = 0;
123 bBoostOverride = false;
124 bTakeoffBoost = false;
125 TakeoffBoost = 0.0; // Default to no extra takeoff-boost
126 BoostLossFactor = 0.0; // Default to free boost
127
128 int i;
129 for (i=0; i<FG_MAX_BOOST_SPEEDS; i++) {
130 RatedBoost[i] = 0.0;
131 RatedPower[i] = 0.0;
132 RatedAltitude[i] = 0.0;
133 BoostMul[i] = 1.0;
134 RatedMAP[i] = 100000;
135 RatedRPM[i] = 2500;
136 TakeoffMAP[i] = 100000;
137 }
138 for (i=0; i<FG_MAX_BOOST_SPEEDS-1; i++) {
139 BoostSwitchAltitude[i] = 0.0;
140 BoostSwitchPressure[i] = 0.0;
141 }
142
143 // Read inputs from engine data file where present.
144
145 if (el->FindElement("minmp"))
146 MinManifoldPressure_inHg = el->FindElementValueAsNumberConvertTo("minmp","INHG");
147 if (el->FindElement("maxmp"))
148 MaxManifoldPressure_inHg = el->FindElementValueAsNumberConvertTo("maxmp","INHG");
149 if (el->FindElement("man-press-lag"))
150 ManifoldPressureLag = el->FindElementValueAsNumber("man-press-lag");
151 if (el->FindElement("displacement"))
152 Displacement = el->FindElementValueAsNumberConvertTo("displacement","IN3");
153 if (el->FindElement("maxhp"))
154 MaxHP = el->FindElementValueAsNumberConvertTo("maxhp","HP");
155 if (el->FindElement("static-friction"))
156 StaticFriction_HP = el->FindElementValueAsNumberConvertTo("static-friction","HP");
157 if (el->FindElement("sparkfaildrop"))
158 SparkFailDrop = Constrain(0, 1 - el->FindElementValueAsNumber("sparkfaildrop"), 1);
159 if (el->FindElement("cycles"))
160 Cycles = el->FindElementValueAsNumber("cycles");
161 if (el->FindElement("idlerpm"))
162 IdleRPM = el->FindElementValueAsNumber("idlerpm");
163 if (el->FindElement("maxrpm"))
164 MaxRPM = el->FindElementValueAsNumber("maxrpm");
165 if (el->FindElement("maxthrottle"))
166 MaxThrottle = el->FindElementValueAsNumber("maxthrottle");
167 if (el->FindElement("minthrottle"))
168 MinThrottle = el->FindElementValueAsNumber("minthrottle");
169 if (el->FindElement("bsfc"))
170 ISFC = el->FindElementValueAsNumberConvertTo("bsfc", "LBS/HP*HR");
171 if (el->FindElement("volumetric-efficiency"))
172 volumetric_efficiency = el->FindElementValueAsNumber("volumetric-efficiency");
173 if (el->FindElement("compression-ratio"))
174 CompressionRatio = el->FindElementValueAsNumber("compression-ratio");
175 if (el->FindElement("bore"))
176 Bore = el->FindElementValueAsNumberConvertTo("bore","IN");
177 if (el->FindElement("stroke"))
178 Stroke = el->FindElementValueAsNumberConvertTo("stroke","IN");
179 if (el->FindElement("cylinders"))
180 Cylinders = el->FindElementValueAsNumber("cylinders");
181 if (el->FindElement("cylinder-head-mass"))
182 CylinderHeadMass = el->FindElementValueAsNumberConvertTo("cylinder-head-mass","KG");
183 if (el->FindElement("air-intake-impedance-factor"))
184 Z_airbox = el->FindElementValueAsNumber("air-intake-impedance-factor");
185 if (el->FindElement("ram-air-factor"))
186 Ram_Air_Factor = el->FindElementValueAsNumber("ram-air-factor");
187 if (el->FindElement("cooling-factor"))
188 Cooling_Factor = el->FindElementValueAsNumber("cooling-factor");
189 if (el->FindElement("starter-rpm"))
190 StarterRPM = el->FindElementValueAsNumber("starter-rpm");
191 if (el->FindElement("starter-torque"))
192 StarterTorque = el->FindElementValueAsNumber("starter-torque");
193 if (el->FindElement("dynamic-fmep"))
194 FMEPDynamic= el->FindElementValueAsNumberConvertTo("dynamic-fmep","PA");
195 if (el->FindElement("static-fmep"))
196 FMEPStatic = el->FindElementValueAsNumberConvertTo("static-fmep","PA");
197 if (el->FindElement("peak-piston-speed"))
198 PeakMeanPistonSpeed_fps = el->FindElementValueAsNumber("peak-piston-speed");
199 if (el->FindElement("numboostspeeds")) { // Turbo- and super-charging parameters
200 BoostSpeeds = (int)el->FindElementValueAsNumber("numboostspeeds");
201 if (el->FindElement("boostoverride"))
202 BoostOverride = (int)el->FindElementValueAsNumber("boostoverride");
203 if (el->FindElement("boostmanual"))
204 BoostManual = (int)el->FindElementValueAsNumber("boostmanual");
205 if (el->FindElement("takeoffboost"))
206 TakeoffBoost = el->FindElementValueAsNumberConvertTo("takeoffboost", "PSI");
207 if (el->FindElement("boost-loss-factor"))
208 BoostLossFactor = el->FindElementValueAsNumber("boost-loss-factor");
209 if (el->FindElement("ratedboost1"))
210 RatedBoost[0] = el->FindElementValueAsNumberConvertTo("ratedboost1", "PSI");
211 if (el->FindElement("ratedboost2"))
212 RatedBoost[1] = el->FindElementValueAsNumberConvertTo("ratedboost2", "PSI");
213 if (el->FindElement("ratedboost3"))
214 RatedBoost[2] = el->FindElementValueAsNumberConvertTo("ratedboost3", "PSI");
215 if (el->FindElement("ratedpower1"))
216 RatedPower[0] = el->FindElementValueAsNumberConvertTo("ratedpower1", "HP");
217 if (el->FindElement("ratedpower2"))
218 RatedPower[1] = el->FindElementValueAsNumberConvertTo("ratedpower2", "HP");
219 if (el->FindElement("ratedpower3"))
220 RatedPower[2] = el->FindElementValueAsNumberConvertTo("ratedpower3", "HP");
221 if (el->FindElement("ratedrpm1"))
222 RatedRPM[0] = el->FindElementValueAsNumber("ratedrpm1");
223 if (el->FindElement("ratedrpm2"))
224 RatedRPM[1] = el->FindElementValueAsNumber("ratedrpm2");
225 if (el->FindElement("ratedrpm3"))
226 RatedRPM[2] = el->FindElementValueAsNumber("ratedrpm3");
227 if (el->FindElement("ratedaltitude1"))
228 RatedAltitude[0] = el->FindElementValueAsNumberConvertTo("ratedaltitude1", "FT");
229 if (el->FindElement("ratedaltitude2"))
230 RatedAltitude[1] = el->FindElementValueAsNumberConvertTo("ratedaltitude2", "FT");
231 if (el->FindElement("ratedaltitude3"))
232 RatedAltitude[2] = el->FindElementValueAsNumberConvertTo("ratedaltitude3", "FT");
233 }
234
235 Design_Oil_Temp = 358; // degK;
236 Oil_Viscosity_Index = 0.25;
237 Oil_Press_Relief_Valve = 60; // psi
238 Oil_Press_RPM_Max = MaxRPM*0.75;
239 if (el->FindElement("oil-pressure-relief-valve-psi"))
240 Oil_Press_Relief_Valve = el->FindElementValueAsNumberConvertTo("oil-pressure-relief-valve-psi", "PSI");
241 if (el->FindElement("design-oil-temp-degK"))
242 Design_Oil_Temp = el->FindElementValueAsNumberConvertTo("design-oil-temp-degK", "DEGK");
243 if (el->FindElement("oil-pressure-rpm-max"))
244 Oil_Press_RPM_Max = el->FindElementValueAsNumber("oil-pressure-rpm-max");
245 if (el->FindElement("oil-viscosity-index"))
246 Oil_Viscosity_Index = el->FindElementValueAsNumber("oil-viscosity-index");
247
248 while((table_element = el->FindNextElement("table")) != 0) {
249 string name = table_element->GetAttributeValue("name");
250 try {
251 if (name == "COMBUSTION") {
252 Lookup_Combustion_Efficiency = new FGTable(PropertyManager, table_element);
253 } else if (name == "MIXTURE") {
254 Mixture_Efficiency_Correlation = new FGTable(PropertyManager, table_element);
255 } else {
256 cerr << "Unknown table type: " << name << " in piston engine definition." << endl;
257 }
258 } catch (std::string& str) {
259 // Make sure allocated resources are freed before rethrowing.
260 // (C++ standard guarantees that a null pointer deletion is no-op).
261 delete Lookup_Combustion_Efficiency;
262 delete Mixture_Efficiency_Correlation;
263 throw("Error loading piston engine table:" + name + ". " + str);
264 }
265 }
266
267
268 volumetric_efficiency_reduced = volumetric_efficiency;
269
270 if(StarterRPM < 0.) StarterRPM = 2*IdleRPM;
271 if(StarterTorque < 0)
272 StarterTorque = (MaxHP)*0.4; //just a wag.
273
274 displacement_SI = Displacement * in3tom3;
275 RatedMeanPistonSpeed_fps = ( MaxRPM * Stroke) / (360); // AKA 2 * (RPM/60) * ( Stroke / 12) or 2NS
276
277 // Create IFSC to match the engine if not provided
278 if (ISFC < 0) {
279 double pmep = 29.92 - MaxManifoldPressure_inHg;
280 pmep *= inhgtopa * volumetric_efficiency;
281 double fmep = (FMEPDynamic * RatedMeanPistonSpeed_fps * fttom + FMEPStatic);
282 double hp_loss = ((pmep + fmep) * displacement_SI * MaxRPM)/(Cycles*22371);
283 ISFC = ( 1.1*Displacement * MaxRPM * volumetric_efficiency *(MaxManifoldPressure_inHg / 29.92) ) / (9411 * (MaxHP+hp_loss-StaticFriction_HP));
284// cout <<"FMEP: "<< fmep <<" PMEP: "<< pmep << " hp_loss: " <<hp_loss <<endl;
285 }
286 if ( MaxManifoldPressure_inHg > 29.9 ) { // Don't allow boosting with a bogus number
287 MaxManifoldPressure_inHg = 29.9;
288 }
289 minMAP = MinManifoldPressure_inHg * inhgtopa; // inHg to Pa
290 maxMAP = MaxManifoldPressure_inHg * inhgtopa;
291
292// For throttle
293/*
294 * Pm = ( Ze / ( Ze + Zi + Zt ) ) * Pa
295 * Where:
296 * Pm = Manifold Pressure
297 * Pa = Ambient Pressre
298 * Ze = engine impedance, Ze is effectively 1 / Mean Piston Speed
299 * Zi = airbox impedance
300 * Zt = throttle impedance
301 *
302 * For the calculation below throttle is fully open or Zt = 0
303 *
304 *
305 *
306 */
307 if(Z_airbox < 0.0){
308 double Ze=PeakMeanPistonSpeed_fps/RatedMeanPistonSpeed_fps; // engine impedence
309 Z_airbox = (standard_pressure *Ze / maxMAP) - Ze; // impedence of airbox
310 }
311 // Constant for Throttle impedence
312 Z_throttle=(PeakMeanPistonSpeed_fps/((IdleRPM * Stroke) / 360))*(standard_pressure/minMAP - 1) - Z_airbox;
313 // Z_throttle=(MaxRPM/IdleRPM )*(standard_pressure/minMAP+2); // Constant for Throttle impedence
314
315// Default tables if not provided in the configuration file
316 if(Lookup_Combustion_Efficiency == 0) {
317 // First column is thi, second is neta (combustion efficiency)
318 Lookup_Combustion_Efficiency = new FGTable(12);
319 *Lookup_Combustion_Efficiency << 0.00 << 0.980;
320 *Lookup_Combustion_Efficiency << 0.90 << 0.980;
321 *Lookup_Combustion_Efficiency << 1.00 << 0.970;
322 *Lookup_Combustion_Efficiency << 1.05 << 0.950;
323 *Lookup_Combustion_Efficiency << 1.10 << 0.900;
324 *Lookup_Combustion_Efficiency << 1.15 << 0.850;
325 *Lookup_Combustion_Efficiency << 1.20 << 0.790;
326 *Lookup_Combustion_Efficiency << 1.30 << 0.700;
327 *Lookup_Combustion_Efficiency << 1.40 << 0.630;
328 *Lookup_Combustion_Efficiency << 1.50 << 0.570;
329 *Lookup_Combustion_Efficiency << 1.60 << 0.525;
330 *Lookup_Combustion_Efficiency << 2.00 << 0.345;
331 }
332
333 // First column is Fuel/Air Ratio, second is neta (mixture efficiency)
334 if( Mixture_Efficiency_Correlation == 0) {
335 Mixture_Efficiency_Correlation = new FGTable(15);
336 *Mixture_Efficiency_Correlation << 0.05000 << 0.00000;
337 *Mixture_Efficiency_Correlation << 0.05137 << 0.00862;
338 *Mixture_Efficiency_Correlation << 0.05179 << 0.21552;
339 *Mixture_Efficiency_Correlation << 0.05430 << 0.48276;
340 *Mixture_Efficiency_Correlation << 0.05842 << 0.70690;
341 *Mixture_Efficiency_Correlation << 0.06312 << 0.83621;
342 *Mixture_Efficiency_Correlation << 0.06942 << 0.93103;
343 *Mixture_Efficiency_Correlation << 0.07786 << 1.00000;
344 *Mixture_Efficiency_Correlation << 0.08845 << 1.00000;
345 *Mixture_Efficiency_Correlation << 0.09270 << 0.98276;
346 *Mixture_Efficiency_Correlation << 0.10120 << 0.93103;
347 *Mixture_Efficiency_Correlation << 0.11455 << 0.72414;
348 *Mixture_Efficiency_Correlation << 0.12158 << 0.45690;
349 *Mixture_Efficiency_Correlation << 0.12435 << 0.23276;
350 *Mixture_Efficiency_Correlation << 0.12500 << 0.00000;
351 }
352
353 string property_name, base_property_name;
354 base_property_name = CreateIndexedPropertyName("propulsion/engine", EngineNumber);
355 property_name = base_property_name + "/power-hp";
356 PropertyManager->Tie(property_name, &HP);
357 property_name = base_property_name + "/friction-hp";
358 PropertyManager->Tie(property_name, &StaticFriction_HP);
359 property_name = base_property_name + "/bsfc-lbs_hphr";
360 PropertyManager->Tie(property_name, &ISFC);
361 property_name = base_property_name + "/starter-norm";
362 PropertyManager->Tie(property_name, &StarterGain);
363 property_name = base_property_name + "/volumetric-efficiency";
364 PropertyManager->Tie(property_name, &volumetric_efficiency);
365 property_name = base_property_name + "/map-pa";
366 PropertyManager->Tie(property_name, &MAP);
367 property_name = base_property_name + "/map-inhg";
368 PropertyManager->Tie(property_name, &ManifoldPressure_inHg);
369 property_name = base_property_name + "/air-intake-impedance-factor";
370 PropertyManager->Tie(property_name, &Z_airbox);
371 property_name = base_property_name + "/ram-air-factor";
372 PropertyManager->Tie(property_name, &Ram_Air_Factor);
373 property_name = base_property_name + "/cooling-factor";
374 PropertyManager->Tie(property_name, &Cooling_Factor);
375 property_name = base_property_name + "/boost-speed";
376 PropertyManager->Tie(property_name, &BoostSpeed);
377 property_name = base_property_name + "/cht-degF";
378 PropertyManager->Tie(property_name, this, &FGPiston::getCylinderHeadTemp_degF);
379 property_name = base_property_name + "/oil-temperature-degF";
380 PropertyManager->Tie(property_name, this, &FGPiston::getOilTemp_degF);
381 property_name = base_property_name + "/oil-pressure-psi";
382 PropertyManager->Tie(property_name, this, &FGPiston::getOilPressure_psi);
383 property_name = base_property_name + "/egt-degF";
384 PropertyManager->Tie(property_name, this, &FGPiston::getExhaustGasTemp_degF);
385 if(BoostLossFactor > 0.0) {
386 property_name = base_property_name + "/boostloss-factor";
387 PropertyManager->Tie(property_name, &BoostLossFactor);
388 property_name = base_property_name + "/boostloss-hp";
389 PropertyManager->Tie(property_name, &BoostLossHP);
390 }
391 property_name = base_property_name + "/AFR";
392 PropertyManager->Tie(property_name, this, &FGPiston::getAFR);
393
394 // Set up and sanity-check the turbo/supercharging configuration based on the input values.
395 if (TakeoffBoost > RatedBoost[0]) bTakeoffBoost = true;
396 for (i=0; i<BoostSpeeds; ++i) {
397 bool bad = false;
398 if (RatedBoost[i] <= 0.0) bad = true;
399 if (RatedPower[i] <= 0.0) bad = true;
400 if (RatedAltitude[i] < 0.0) bad = true; // 0.0 is deliberately allowed - this corresponds to unregulated supercharging.
401 if (i > 0 && RatedAltitude[i] < RatedAltitude[i - 1]) bad = true;
402 if (bad) {
403 // We can't recover from the above - don't use this supercharger speed.
404 BoostSpeeds--;
405 // TODO - put out a massive error message!
406 break;
407 }
408 // Now sanity-check stuff that is recoverable.
409 if (i < BoostSpeeds - 1) {
410 if (BoostSwitchAltitude[i] < RatedAltitude[i]) {
411 // TODO - put out an error message
412 // But we can also make a reasonable estimate, as below.
413 BoostSwitchAltitude[i] = RatedAltitude[i] + 1000;
414 }
415 BoostSwitchPressure[i] = GetStdPressure100K(BoostSwitchAltitude[i]) * psftopa;
416 //cout << "BoostSwitchAlt = " << BoostSwitchAltitude[i] << ", pressure = " << BoostSwitchPressure[i] << '\n';
417 // Assume there is some hysteresis on the supercharger gear switch, and guess the value for now
418 BoostSwitchHysteresis = 1000;
419 }
420 // Now work out the supercharger pressure multiplier of this speed from the rated boost and altitude.
421 RatedMAP[i] = standard_pressure + RatedBoost[i] * 6895; // psi*6895 = Pa.
422 // Sometimes a separate BCV setting for takeoff or extra power is fitted.
423 if (TakeoffBoost > RatedBoost[0]) {
424 // Assume that the effect on the BCV is the same whichever speed is in use.
425 TakeoffMAP[i] = RatedMAP[i] + ((TakeoffBoost - RatedBoost[0]) * 6895);
426 bTakeoffBoost = true;
427 } else {
428 TakeoffMAP[i] = RatedMAP[i];
429 bTakeoffBoost = false;
430 }
431 BoostMul[i] = RatedMAP[i] / (GetStdPressure100K(RatedAltitude[i]) * psftopa);
432
433 }
434
435 if (BoostSpeeds > 0) {
436 Boosted = true;
437 BoostSpeed = 0;
438 }
439 bBoostOverride = (BoostOverride == 1 ? true : false);
440 bBoostManual = (BoostManual == 1 ? true : false);
441 Debug(0); // Call Debug() routine from constructor if needed
442}
443
444//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
445
446FGPiston::~FGPiston()
447{
448 delete Lookup_Combustion_Efficiency;
449 delete Mixture_Efficiency_Correlation;
450 Debug(1); // Call Debug() routine from constructor if needed
451}
452
453//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
454
455void FGPiston::ResetToIC(void)
456{
457 FGEngine::ResetToIC();
458
459 ManifoldPressure_inHg = in.Pressure * psftoinhg; // psf to in Hg
460 MAP = in.Pressure * psftopa;
461 TMAP = MAP;
462 double airTemperature_degK = RankineToKelvin(in.Temperature);
463 OilTemp_degK = airTemperature_degK;
464 CylinderHeadTemp_degK = airTemperature_degK;
465 ExhaustGasTemp_degK = airTemperature_degK;
466 EGT_degC = ExhaustGasTemp_degK - 273;
467 Thruster->SetRPM(0.0);
468 RPM = 0.0;
469 OilPressure_psi = 0.0;
470 BoostLossHP = 0.;
471}
472
473//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
474
475void FGPiston::Calculate(void)
476{
477 // Input values.
478
479 p_amb = in.Pressure * psftopa;
480 double p = in.TotalPressure * psftopa;
481 p_ram = (p - p_amb) * Ram_Air_Factor + p_amb;
482 T_amb = RankineToKelvin(in.Temperature);
483
484 RunPreFunctions();
485
486/* The thruster controls the engine RPM because it encapsulates the gear ratio and other transmission variables */
487 RPM = Thruster->GetEngineRPM();
488
489 MeanPistonSpeed_fps = ( RPM * Stroke) / (360); // AKA 2 * (RPM/60) * ( Stroke / 12) or 2NS
490
491 IAS = in.Vc;
492
493 doEngineStartup();
494 if (Boosted) doBoostControl();
495 doMAP();
496 doAirFlow();
497 doFuelFlow();
498
499 //Now that the fuel flow is done check if the mixture is too lean to run the engine
500 //Assume lean limit at 22 AFR for now - thats a thi of 0.668
501 //This might be a bit generous, but since there's currently no audiable warning of impending
502 //cutout in the form of misfiring and/or rough running its probably reasonable for now.
503
504 // if (equivalence_ratio < 0.668)
505 // Running = false;
506
507 doEnginePower();
508 if (IndicatedHorsePower < 0.1250) Running = false;
509
510 doEGT();
511 doCHT();
512 doOilTemperature();
513 doOilPressure();
514
515 if (Thruster->GetType() == FGThruster::ttPropeller) {
516 ((FGPropeller*)Thruster)->SetAdvance(in.PropAdvance[EngineNumber]);
517 ((FGPropeller*)Thruster)->SetFeather(in.PropFeather[EngineNumber]);
518 }
519
520 LoadThrusterInputs();
521 // Filters out negative powers when the propeller is not rotating.
522 double power = HP * hptoftlbssec;
523 if (RPM <= 0.1) power = max(power, 0.0);
524 Thruster->Calculate(power);
525
526 RunPostFunctions();
527}
528
529//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
530
531double FGPiston::CalcFuelNeed(void)
532{
533 FuelExpended = FuelFlowRate * in.TotalDeltaT;
534 if (!Starved) FuelUsedLbs += FuelExpended;
535 return FuelExpended;
536}
537
538//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
539
540int FGPiston::InitRunning(void)
541{
542 Magnetos=3;
543 in.MixtureCmd[EngineNumber] = in.PressureRatio*1.3;
544 in.MixturePos[EngineNumber] = in.PressureRatio*1.3;
545 Thruster->SetRPM( 2.0*IdleRPM/Thruster->GetGearRatio() );
546 Running = true;
547 return 1;
548}
549
550//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
555void FGPiston::doEngineStartup(void)
556{
557 // Check parameters that may alter the operating state of the engine.
558 // (spark, fuel, starter motor etc)
559 bool spark;
560 bool fuel;
561 // Check for spark
562 Magneto_Left = false;
563 Magneto_Right = false;
564 // Magneto positions:
565 // 0 -> off
566 // 1 -> left only
567 // 2 -> right only
568 // 3 -> both
569 if (Magnetos != 0) {
570 spark = true;
571 } else {
572 spark = false;
573 } // neglects battery voltage, master on switch, etc for now.
574
575 if ((Magnetos == 1) || (Magnetos > 2)) Magneto_Left = true;
576 if (Magnetos > 1) Magneto_Right = true;
577
578// We will 'run' with any fuel flow. If there is not enough fuel to make power it will show in doEnginePower
579 fuel = FuelFlowRate > 0.0 ? 1 : 0;
580
581 // Check if we are turning the starter motor
582 if (Cranking != Starter) {
583 // This check saves .../cranking from getting updated every loop - they
584 // only update when changed.
585 Cranking = Starter;
586 }
587
588
589 // Cut the engine *power* - Note: the engine will continue to
590 // spin depending on prop Ixx and freestream velocity
591
592 if ( Running ) {
593 if (!spark || !fuel) Running = false;
594 if (RPM < IdleRPM*0.8 ) Running = false;
595 } else { // !Running
596 if ( spark && fuel) { // start the engine if revs high enough
597 if (RPM > IdleRPM*0.8) // This allows us to in-air start
598 Running = true; // when windmilling
599 }
600 }
601
602}
603
604//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
605
617void FGPiston::doBoostControl(void)
618{
619 if(bBoostManual) {
620 if(BoostSpeed > BoostSpeeds-1) BoostSpeed = BoostSpeeds-1;
621 if(BoostSpeed < 0) BoostSpeed = 0;
622 } else {
623 if(BoostSpeed < BoostSpeeds - 1) {
624 // Check if we need to change to a higher boost speed
625 if(p_amb < BoostSwitchPressure[BoostSpeed] - BoostSwitchHysteresis) {
626 BoostSpeed++;
627 }
628 } if(BoostSpeed > 0) {
629 // Check if we need to change to a lower boost speed
630 if(p_amb > BoostSwitchPressure[BoostSpeed - 1] + BoostSwitchHysteresis) {
631 BoostSpeed--;
632 }
633 }
634 }
635}
636
637//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
638
652void FGPiston::doMAP(void)
653{
654 double Zt = (1 - in.ThrottlePos[EngineNumber])*(1 - in.ThrottlePos[EngineNumber])*Z_throttle; // throttle impedence
655 double Ze= MeanPistonSpeed_fps > 0 ? PeakMeanPistonSpeed_fps/MeanPistonSpeed_fps : 999999; // engine impedence
656
657 double map_coefficient = Ze/(Ze+Z_airbox+Zt);
658
659 // Add a variable lag to manifold pressure changes
660 double dMAP=(TMAP - p_ram * map_coefficient);
661 if (ManifoldPressureLag > in.TotalDeltaT) dMAP *= in.TotalDeltaT/ManifoldPressureLag;
662
663 TMAP -=dMAP;
664
665 // Find the mean effective pressure required to achieve this manifold pressure
666 // Fixme: determine the HP consumed by the supercharger
667
668 PMEP = (TMAP - p_amb) * volumetric_efficiency; // Fixme: p_amb should be exhaust manifold pressure
669
670 if (Boosted) {
671 // If takeoff boost is fitted, we currently assume the following throttle map:
672 // (In throttle % - actual input is 0 -> 1)
673 // 99 / 100 - Takeoff boost
674 // In real life, most planes would be fitted with a mechanical 'gate' between
675 // the rated boost and takeoff boost positions.
676
677 bool bTakeoffPos = false;
678 if (bTakeoffBoost) {
679 if (in.ThrottlePos[EngineNumber] > 0.98) {
680 bTakeoffPos = true;
681 }
682 }
683 // Boost the manifold pressure.
684 double boost_factor = (( BoostMul[BoostSpeed] - 1 ) / RatedRPM[BoostSpeed] ) * RPM + 1;
685 MAP = TMAP * boost_factor;
686 // Now clip the manifold pressure to BCV or Wastegate setting.
687 if(!bBoostOverride) {
688 if (bTakeoffPos) {
689 if (MAP > TakeoffMAP[BoostSpeed]) MAP = TakeoffMAP[BoostSpeed];
690 } else {
691 if (MAP > RatedMAP[BoostSpeed]) MAP = RatedMAP[BoostSpeed];
692 }
693 }
694 } else {
695 MAP = TMAP;
696 }
697
698 if( BoostLossFactor > 0.0 )
699 {
700 double gamma = 1.414; // specific heat constants
701 double Nstage = 1; // Nstage is the number of boost stages.
702 BoostLossHP = ((Nstage * TMAP * v_dot_air * gamma) / (gamma - 1)) * (pow((MAP/TMAP),((gamma-1)/(Nstage * gamma))) - 1) * BoostLossFactor / 745.7 ; // 745.7 convert watt to hp
703 } else {
704 BoostLossHP = 0;
705 }
706
707 // And set the value in American units as well
708 ManifoldPressure_inHg = MAP / inhgtopa;
709}
710
711//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
725void FGPiston::doAirFlow(void)
726{
727 double gamma = 1.3; // specific heat constants
728// loss of volumentric efficiency due to difference between MAP and exhaust pressure
729// Eq 6-10 from The Internal Combustion Engine - Charles Taylor Vol 1
730 double mratio = MAP < 1. ? CompressionRatio : p_amb/MAP;
731 if (mratio > CompressionRatio) mratio = CompressionRatio;
732 double ve =((gamma-1)/gamma) +( CompressionRatio -(mratio))/(gamma*( CompressionRatio - 1));
733
734 rho_air = p_amb / (R_air * T_amb);
735 double swept_volume = (displacement_SI * (RPM/60)) / 2;
736 volumetric_efficiency_reduced = volumetric_efficiency *ve;
737 v_dot_air = swept_volume * volumetric_efficiency_reduced;
738
739 double rho_air_manifold = MAP / (R_air * T_amb);
740 m_dot_air = v_dot_air * rho_air_manifold;
741
742}
743
744//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
753void FGPiston::doFuelFlow(void)
754{
755 double thi_sea_level = 1.3 * in.MixturePos[EngineNumber]; // Allows an AFR of infinity:1 to 11.3075:1
756 equivalence_ratio = thi_sea_level * 101325.0 / p_amb;
757 m_dot_fuel = (m_dot_air * equivalence_ratio) / 14.7;
758 FuelFlowRate = m_dot_fuel * 2.2046; // kg to lb
759 if(Starved) // There is no fuel, so zero out the flows we've calculated so far
760 {
761 equivalence_ratio = 0.0;
762 FuelFlowRate = 0.0;
763 m_dot_fuel = 0.0;
764 }
765 FuelFlow_pph = FuelFlowRate * 3600;
766 FuelFlow_gph = FuelFlow_pph / FuelDensity;
767}
768
769//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
780void FGPiston::doEnginePower(void)
781{
782 IndicatedHorsePower = -StaticFriction_HP;
783 FMEP = 0;
784 if (Running) {
785 double ME, power; // Convienience term for use in the calculations
786 ME = Mixture_Efficiency_Correlation->GetValue(m_dot_fuel/m_dot_air);
787
788// Guestimate engine friction losses from Figure 4.4 of "Engines: An Introduction", John Lumley
789 FMEP = (-FMEPDynamic * MeanPistonSpeed_fps * fttom - FMEPStatic);
790
791 power = 1;
792
793 if ( Magnetos != 3 ) power *= SparkFailDrop;
794
795
796 IndicatedHorsePower = (FuelFlow_pph / ISFC )* ME * power - StaticFriction_HP; //FIXME static friction should depend on oil temp and configuration;
797
798 } else {
799 // Power output when the engine is not running
800 double torque, k_torque, rpm; // Convienience term for use in the calculations
801
802 rpm = RPM < 1.0 ? 1.0 : RPM;
803 if (Cranking) {
804 if(RPM<StarterRPM) k_torque = 1.0-RPM/(StarterRPM);
805 else k_torque = 0;
806 torque = StarterTorque*k_torque*StarterGain;
807 IndicatedHorsePower = torque * rpm / 5252;
808 }
809 }
810
811 // Constant is (1/2) * 60 * 745.7
812 // (1/2) convert cycles, 60 minutes to seconds, 745.7 watts to hp.
813 double pumping_hp = ((PMEP + FMEP) * displacement_SI * RPM)/(Cycles*22371);
814
815HP = IndicatedHorsePower + pumping_hp - BoostLossHP;
816// cout << "pumping_hp " <<pumping_hp << FMEP << PMEP <<endl;
817 PctPower = HP / MaxHP ;
818// cout << "Power = " << HP << " RPM = " << RPM << " Running = " << Running << " Cranking = " << Cranking << endl;
819}
820
821//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
831void FGPiston::doEGT(void)
832{
833 double delta_T_exhaust;
834 double enthalpy_exhaust;
835 double heat_capacity_exhaust;
836 double dEGTdt;
837
838 if ((Running) && (m_dot_air > 0.0)) { // do the energy balance
839 combustion_efficiency = Lookup_Combustion_Efficiency->GetValue(equivalence_ratio);
840 enthalpy_exhaust = m_dot_fuel * calorific_value_fuel *
841 combustion_efficiency * 0.30;
842 heat_capacity_exhaust = (Cp_air * m_dot_air) + (Cp_fuel * m_dot_fuel);
843 delta_T_exhaust = enthalpy_exhaust / heat_capacity_exhaust;
844 ExhaustGasTemp_degK = T_amb + delta_T_exhaust;
845 } else { // Drop towards ambient - guess an appropriate time constant for now
846 combustion_efficiency = 0;
847 dEGTdt = (RankineToKelvin(in.Temperature) - ExhaustGasTemp_degK) / 100.0;
848 delta_T_exhaust = dEGTdt * in.TotalDeltaT;
849
850 ExhaustGasTemp_degK += delta_T_exhaust;
851 }
852}
853
854//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
864void FGPiston::doCHT(void)
865{
866 double h1 = -95.0;
867 double h2 = -3.95;
868 double h3 = -140.0; // -0.05 * 2800 (default maxrpm)
869
870 double arbitary_area = Displacement/360.0;
871 double CpCylinderHead = 800.0;
872 double MassCylinderHead = CylinderHeadMass * Cylinders;
873
874 double temperature_difference = CylinderHeadTemp_degK - T_amb;
875 double v_apparent = IAS * Cooling_Factor;
876 double v_dot_cooling_air = arbitary_area * v_apparent;
877 double m_dot_cooling_air = v_dot_cooling_air * rho_air;
878 double dqdt_from_combustion =
879 m_dot_fuel * calorific_value_fuel * combustion_efficiency * 0.33;
880 double dqdt_forced = (h2 * m_dot_cooling_air * temperature_difference) +
881 (h3 * RPM * temperature_difference / MaxRPM);
882 double dqdt_free = h1 * temperature_difference * arbitary_area;
883 double dqdt_cylinder_head = dqdt_from_combustion + dqdt_forced + dqdt_free;
884
885 double HeatCapacityCylinderHead = CpCylinderHead * MassCylinderHead;
886
887 CylinderHeadTemp_degK +=
888 (dqdt_cylinder_head / HeatCapacityCylinderHead) * in.TotalDeltaT;
889
890}
891
892//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
901void FGPiston::doOilTemperature(void)
902{
903 double target_oil_temp; // Steady state oil temp at the current engine conditions
904 double time_constant; // The time constant for the differential equation
905 double efficiency = 0.667; // The aproximate oil cooling system efficiency // FIXME: may vary by engine
906
907// Target oil temp is interpolated between ambient temperature and Cylinder Head Tempurature
908// target_oil_temp = ( T_amb * efficiency ) + (CylinderHeadTemp_degK *(1-efficiency)) ;
909 target_oil_temp = CylinderHeadTemp_degK + efficiency * (T_amb - CylinderHeadTemp_degK) ;
910
911 if (OilPressure_psi > 5.0 ) {
912 time_constant = 5000 / OilPressure_psi; // Guess at a time constant for circulated oil.
913 // The higher the pressure the faster it reaches
914 // target temperature. Oil pressure should be about
915 // 60 PSI yielding a TC of about 80.
916 } else {
917 time_constant = 1000; // Time constant for engine-off; reflects the fact
918 // that oil is no longer getting circulated
919 }
920
921 double dOilTempdt = (target_oil_temp - OilTemp_degK) / time_constant;
922
923 OilTemp_degK += (dOilTempdt * in.TotalDeltaT);
924}
925
926//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
935void FGPiston::doOilPressure(void)
936{
937 OilPressure_psi = (Oil_Press_Relief_Valve / Oil_Press_RPM_Max) * RPM;
938
939 if (OilPressure_psi >= Oil_Press_Relief_Valve) {
940 OilPressure_psi = Oil_Press_Relief_Valve;
941 }
942
943 OilPressure_psi += (Design_Oil_Temp - OilTemp_degK) * Oil_Viscosity_Index * OilPressure_psi / Oil_Press_Relief_Valve;
944}
945
946//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
947//
948// This is a local copy of the same function in FGStandardAtmosphere.
949
950double FGPiston::GetStdPressure100K(double altitude) const
951{
952 // Limit this equation to input altitudes of 100000 ft.
953 if (altitude > 100000.0) altitude = 100000.0;
954
955 double alt[5];
956 const double coef[5] = { 2116.217,
957 -7.648932746E-2,
958 1.0925498604E-6,
959 -7.1135726027E-12,
960 1.7470331356E-17 };
961
962 alt[0] = 1;
963 for (int pwr=1; pwr<=4; pwr++) alt[pwr] = alt[pwr-1]*altitude;
964
965 double press = 0.0;
966 for (int ctr=0; ctr<=4; ctr++) press += coef[ctr]*alt[ctr];
967 return press;
968}
969
970//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
971
972string FGPiston::GetEngineLabels(const string& delimiter)
973{
974 std::ostringstream buf;
975
976 buf << Name << " Power Available (engine " << EngineNumber << " in ft-lbs/sec)" << delimiter
977 << Name << " HP (engine " << EngineNumber << ")" << delimiter
978 << Name << " equivalent ratio (engine " << EngineNumber << ")" << delimiter
979 << Name << " MAP (engine " << EngineNumber << " in inHg)" << delimiter
980 << Thruster->GetThrusterLabels(EngineNumber, delimiter);
981
982 return buf.str();
983}
984
985//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
986
987string FGPiston::GetEngineValues(const string& delimiter)
988{
989 std::ostringstream buf;
990
991 buf << (HP * hptoftlbssec) << delimiter << HP << delimiter
992 << equivalence_ratio << delimiter << ManifoldPressure_inHg << delimiter
993 << Thruster->GetThrusterValues(EngineNumber, delimiter);
994
995 return buf.str();
996}
997
998//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
999//
1000// The bitmasked value choices are as follows:
1001// unset: In this case (the default) JSBSim would only print
1002// out the normally expected messages, essentially echoing
1003// the config files as they are read. If the environment
1004// variable is not set, debug_lvl is set to 1 internally
1005// 0: This requests JSBSim not to output any messages
1006// whatsoever.
1007// 1: This value explicity requests the normal JSBSim
1008// startup messages
1009// 2: This value asks for a message to be printed out when
1010// a class is instantiated
1011// 4: When this value is set, a message is displayed when a
1012// FGModel object executes its Run() method
1013// 8: When this value is set, various runtime state variables
1014// are printed out periodically
1015// 16: When set various parameters are sanity checked and
1016// a message is printed out when they go out of bounds
1017
1018void FGPiston::Debug(int from)
1019{
1020 if (debug_lvl <= 0) return;
1021
1022 if (debug_lvl & 1) { // Standard console startup message output
1023 if (from == 0) { // Constructor
1024
1025 cout << "\n Engine Name: " << Name << endl;
1026 cout << " MinManifoldPressure: " << MinManifoldPressure_inHg << endl;
1027 cout << " MaxManifoldPressure: " << MaxManifoldPressure_inHg << endl;
1028 cout << " MinMaP (Pa): " << minMAP << endl;
1029 cout << " MaxMaP (Pa): " << maxMAP << endl;
1030 cout << " Displacement: " << Displacement << endl;
1031 cout << " Bore: " << Bore << endl;
1032 cout << " Stroke: " << Stroke << endl;
1033 cout << " Cylinders: " << Cylinders << endl;
1034 cout << " Cylinders Head Mass: " << CylinderHeadMass << endl;
1035 cout << " Compression Ratio: " << CompressionRatio << endl;
1036 cout << " MaxHP: " << MaxHP << endl;
1037 cout << " Cycles: " << Cycles << endl;
1038 cout << " IdleRPM: " << IdleRPM << endl;
1039 cout << " MaxRPM: " << MaxRPM << endl;
1040 cout << " Throttle Constant: " << Z_throttle << endl;
1041 cout << " ISFC: " << ISFC << endl;
1042 cout << " Volumetric Efficiency: " << volumetric_efficiency << endl;
1043 cout << " PeakMeanPistonSpeed_fps: " << PeakMeanPistonSpeed_fps << endl;
1044 cout << " Intake Impedance Factor: " << Z_airbox << endl;
1045 cout << " Dynamic FMEP Factor: " << FMEPDynamic << endl;
1046 cout << " Static FMEP Factor: " << FMEPStatic << endl;
1047
1048 cout << " Starter Motor Torque: " << StarterTorque << endl;
1049 cout << " Starter Motor RPM: " << StarterRPM << endl;
1050
1051 cout << endl;
1052 cout << " Combustion Efficiency table:" << endl;
1053 Lookup_Combustion_Efficiency->Print();
1054 cout << endl;
1055
1056 cout << endl;
1057 cout << " Mixture Efficiency Correlation table:" << endl;
1058 Mixture_Efficiency_Correlation->Print();
1059 cout << endl;
1060
1061 }
1062 }
1063 if (debug_lvl & 2 ) { // Instantiation/Destruction notification
1064 if (from == 0) cout << "Instantiated: FGPiston" << endl;
1065 if (from == 1) cout << "Destroyed: FGPiston" << endl;
1066 }
1067 if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
1068 }
1069 if (debug_lvl & 8 ) { // Runtime state variables
1070 }
1071 if (debug_lvl & 16) { // Sanity checking
1072 }
1073 if (debug_lvl & 64) {
1074 if (from == 0) { // Constructor
1075 }
1076 }
1077}
1078} // namespace JSBSim
JSBSim::Element::FindElement
Element * FindElement(const std::string &el="")
Searches for a specified element.
Definition FGXMLElement.cpp:396
JSBSim::Element::GetAttributeValue
std::string GetAttributeValue(const std::string &key)
Retrieves an attribute.
Definition FGXMLElement.cpp:267
JSBSim::Element::FindElementValueAsNumberConvertTo
double FindElementValueAsNumberConvertTo(const std::string &el, const std::string &target_units)
Searches for the named element and converts and returns the data belonging to it.
Definition FGXMLElement.cpp:487
JSBSim::Element::FindNextElement
Element * FindNextElement(const std::string &el="")
Searches for the next element as specified.
Definition FGXMLElement.cpp:414
JSBSim::Element::FindElementValueAsNumber
double FindElementValueAsNumber(const std::string &el="")
Searches for the named element and returns the data belonging to it as a number.
Definition FGXMLElement.cpp:436
JSBSim::FGEngine
Base class for all engines.
Definition FGEngine.h:104
JSBSim::FGEngine::ResetToIC
virtual void ResetToIC(void)
Resets the Engine parameters to the initial conditions.
Definition FGEngine.cpp:77
JSBSim::FGFDMExec
Encapsulates the JSBSim simulation executive.
Definition FGFDMExec.h:184
JSBSim::FGFDMExec::GetPropertyManager
std::shared_ptr< FGPropertyManager > GetPropertyManager(void) const
Returns a pointer to the property manager object.
Definition FGFDMExec.h:421
JSBSim::FGJSBBase::Constrain
static constexpr double Constrain(double min, double value, double max)
Constrain a value between a minimum and a maximum value.
Definition FGJSBBase.h:288
JSBSim::FGJSBBase::RankineToKelvin
static constexpr double RankineToKelvin(double rankine)
Converts from degrees Rankine to degrees Kelvin.
Definition FGJSBBase.h:213
JSBSim::FGPiston::Calculate
void Calculate(void)
Calculates the thrust of the engine, and other engine functions.
Definition FGPiston.cpp:475
JSBSim::FGPiston::~FGPiston
~FGPiston()
Destructor.
Definition FGPiston.cpp:446
JSBSim::FGPiston::ResetToIC
void ResetToIC(void)
Resets the Engine parameters to the initial conditions.
Definition FGPiston.cpp:455
JSBSim::FGPiston::FGPiston
FGPiston(FGFDMExec *exec, Element *el, int engine_number, struct Inputs &input)
Constructor.
Definition FGPiston.cpp:59
JSBSim::FGPiston::CalcFuelNeed
double CalcFuelNeed(void)
The fuel need is calculated based on power levels and flow rate for that power level.
Definition FGPiston.cpp:531
JSBSim::FGPropeller
FGPropeller models a propeller given the tabular data for Ct (thrust) and Cp (power),...
Definition FGPropeller.h:169
JSBSim::FGTable
Lookup table class.
Definition FGTable.h:234
JSBSim::FGTable::GetValue
double GetValue(void) const
Get the current table value.
Definition FGTable.cpp:465