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flightgear/src/FDM/JSBSim/models/propulsion/FGEngine.cpp
2009-10-16 11:22:47 +02:00

380 lines
12 KiB
C++

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Module: FGEngine.cpp
Author: Jon Berndt
Date started: 01/21/99
Called by: FGAircraft
------------- Copyright (C) 1999 Jon S. Berndt (jon@jsbsim.org) -------------
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA.
Further information about the GNU Lesser General Public License can also be found on
the world wide web at http://www.gnu.org.
FUNCTIONAL DESCRIPTION
--------------------------------------------------------------------------------
See header file.
HISTORY
--------------------------------------------------------------------------------
01/21/99 JSB Created
09/03/99 JSB Changed Rocket thrust equation to correct -= Thrust instead of
+= Thrust (thanks to Tony Peden)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
#include "FGEngine.h"
#include "FGTank.h"
#include "FGPropeller.h"
#include "FGNozzle.h"
#include "input_output/FGXMLParse.h"
#include "math/FGColumnVector3.h"
#include <fstream>
namespace JSBSim {
static const char *IdSrc = "$Id$";
static const char *IdHdr = ID_ENGINE;
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS IMPLEMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
FGEngine::FGEngine(FGFDMExec* exec, Element* engine_element, int engine_number)
: EngineNumber(engine_number)
{
Element* local_element;
FGColumnVector3 location, orientation;
Name = "";
Type = etUnknown;
X = Y = Z = 0.0;
EnginePitch = EngineYaw = 0.0;
SLFuelFlowMax = 0.0;
MaxThrottle = 1.0;
MinThrottle = 0.0;
unsigned int i;
ResetToIC(); // initialize dynamic terms
FDMExec = exec;
State = FDMExec->GetState();
Atmosphere = FDMExec->GetAtmosphere();
FCS = FDMExec->GetFCS();
Propulsion = FDMExec->GetPropulsion();
Aircraft = FDMExec->GetAircraft();
Propagate = FDMExec->GetPropagate();
Auxiliary = FDMExec->GetAuxiliary();
PropertyManager = FDMExec->GetPropertyManager();
Name = engine_element->GetAttributeValue("name");
// Find and set engine location
local_element = engine_element->GetParent()->FindElement("location");
if (local_element) location = local_element->FindElementTripletConvertTo("IN");
else cerr << "No engine location found for this engine." << endl;
local_element = engine_element->GetParent()->FindElement("orient");
if (local_element) orientation = local_element->FindElementTripletConvertTo("RAD");
// else cerr << "No engine orientation found for this engine." << endl;
// Jon: The engine orientation has a default and is not normally used.
SetPlacement(location, orientation);
// Load thruster
local_element = engine_element->GetParent()->FindElement("thruster");
if (local_element) {
if (!LoadThruster(local_element)) exit(-1);
} else {
cerr << "No thruster definition supplied with engine definition." << endl;
}
// Build and initialize the feed tank vector.
for (i=0; i<(Propulsion->GetNumTanks()); i++) {
SourceTanks.push_back(0);
}
// Load feed tank[s] references
local_element = engine_element->GetParent()->FindElement("feed");
if (local_element) {
while (local_element) {
int tankID = (int)local_element->GetDataAsNumber();
AddFeedTank( tankID , Propulsion->GetTank(tankID)->GetPriority());
local_element = engine_element->GetParent()->FindNextElement("feed");
}
} else {
cerr << "No feed tank specified in engine definition." << endl;
}
string property_name, base_property_name;
base_property_name = CreateIndexedPropertyName("propulsion/engine", EngineNumber);
property_name = base_property_name + "/set-running";
PropertyManager->Tie( property_name.c_str(), this, &FGEngine::GetRunning, &FGEngine::SetRunning );
property_name = base_property_name + "/thrust-lbs";
PropertyManager->Tie( property_name.c_str(), Thruster, &FGThruster::GetThrust);
property_name = base_property_name + "/fuel-flow-rate-pps";
PropertyManager->Tie( property_name.c_str(), this, &FGEngine::GetFuelFlowRate);
Debug(0);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGEngine::~FGEngine()
{
delete Thruster;
Debug(1);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void FGEngine::ResetToIC(void)
{
Throttle = 0.0;
Mixture = 1.0;
Starter = false;
FuelExpended = 0.0;
Starved = Running = Cranking = false;
PctPower = 0.0;
TrimMode = false;
FuelFlow_gph = 0.0;
FuelFlow_pph = 0.0;
FuelFreeze = false;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// This base class function should be called from within the
// derived class' Calculate() function before any other calculations are done.
// This base class method removes fuel from the fuel tanks as appropriate,
// and sets the starved flag if necessary.
// This version of the fuel consumption code should never see an oxidizer tank.
void FGEngine::ConsumeFuel(void)
{
if (FuelFreeze) return;
if (TrimMode) return;
unsigned int i;
double Fshortage, FuelNeeded;
FGTank* Tank;
unsigned int TanksWithFuel = 0;
Fshortage = FuelNeeded = 0.0;
double FuelToBurn;
unsigned int CurrentPriority = 1;
vector <int> FeedList;
Starved = false;
FuelToBurn = CalcFuelNeed();
while (FuelToBurn > 0.0) {
// Count how many fuel tanks with the current priority level have fuel.
// If none, then try next lower priority. Build the feed list.
while ((TanksWithFuel == 0.0) && (CurrentPriority <= Propulsion->GetNumTanks())) {
for (i=0; i<Propulsion->GetNumTanks(); i++) {
if (SourceTanks[i] != 0) {
Tank = Propulsion->GetTank(i);
if (Tank->GetType() == FGTank::ttFUEL) {
if ((Tank->GetContents() > 0.0) && ((unsigned int)Tank->GetPriority() == CurrentPriority)) {
++TanksWithFuel;
FeedList.push_back(i);
}
} else {
cerr << "No oxidizer tanks should be used for this engine type." << endl;
}
}
}
if (TanksWithFuel == 0) CurrentPriority++;
}
// No fuel found at any priority!
if (TanksWithFuel == 0) {
Starved = true;
return;
}
// Remove equal amount of fuel from each feed tank.
FuelNeeded = FuelToBurn/TanksWithFuel;
for (i=0; i<FeedList.size(); i++) {
Tank = Propulsion->GetTank(FeedList[i]);
Tank->Drain(FuelNeeded);
FuelToBurn -= FuelNeeded;
}
// check if we were not able to burn all the fuel we needed to at this priority level
if (FuelToBurn > 0.001) {
CurrentPriority++;
TanksWithFuel = 0;
FeedList.clear();
}
} // while
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
double FGEngine::CalcFuelNeed(void)
{
double dT = State->Getdt()*Propulsion->GetRate();
FuelFlowRate = SLFuelFlowMax*PctPower;
FuelExpended = FuelFlowRate*dT;
return FuelExpended;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void FGEngine::SetPlacement(FGColumnVector3& location, FGColumnVector3& orientation)
{
X = location(eX);
Y = location(eY);
Z = location(eZ);
EnginePitch = orientation(ePitch);
EngineYaw = orientation (eYaw);
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void FGEngine::AddFeedTank(int tkID, int priority)
{
SourceTanks[tkID] = priority;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGColumnVector3& FGEngine::GetBodyForces(void)
{
return Thruster->GetBodyForces();
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FGColumnVector3& FGEngine::GetMoments(void)
{
return Thruster->GetMoments();
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
bool FGEngine::LoadThruster(Element *thruster_element)
{
string token, fullpath, localpath;
string thruster_filename, thruster_fullpathname, thrType;
string enginePath = FDMExec->GetEnginePath();
string aircraftPath = FDMExec->GetFullAircraftPath();
ifstream thruster_file;
FGColumnVector3 location, orientation;
string separator = "/";
fullpath = enginePath + separator;
localpath = aircraftPath + separator + "Engines" + separator;
thruster_filename = thruster_element->GetAttributeValue("file");
if ( !thruster_filename.empty()) {
thruster_fullpathname = fullpath + thruster_filename + ".xml";
thruster_file.open(thruster_fullpathname.c_str());
if ( !thruster_file.is_open()) {
thruster_fullpathname = localpath + thruster_filename + ".xml";
thruster_file.open(thruster_fullpathname.c_str());
if ( !thruster_file.is_open()) {
cerr << "Could not open thruster file: " << thruster_filename << ".xml" << endl;
return false;
} else {
thruster_file.close();
}
} else {
thruster_file.close();
}
} else {
cerr << "No thruster filename given." << endl;
return false;
}
document = LoadXMLDocument(thruster_fullpathname);
document->SetParent(thruster_element);
thrType = document->GetName();
if (thrType == "propeller") {
Thruster = new FGPropeller(FDMExec, document, EngineNumber);
} else if (thrType == "nozzle") {
Thruster = new FGNozzle(FDMExec, document, EngineNumber);
} else if (thrType == "direct") {
Thruster = new FGThruster( FDMExec, document, EngineNumber);
}
Thruster->SetdeltaT(State->Getdt() * Propulsion->GetRate());
Debug(2);
return true;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
// The bitmasked value choices are as follows:
// unset: In this case (the default) JSBSim would only print
// out the normally expected messages, essentially echoing
// the config files as they are read. If the environment
// variable is not set, debug_lvl is set to 1 internally
// 0: This requests JSBSim not to output any messages
// whatsoever.
// 1: This value explicity requests the normal JSBSim
// startup messages
// 2: This value asks for a message to be printed out when
// a class is instantiated
// 4: When this value is set, a message is displayed when a
// FGModel object executes its Run() method
// 8: When this value is set, various runtime state variables
// are printed out periodically
// 16: When set various parameters are sanity checked and
// a message is printed out when they go out of bounds
void FGEngine::Debug(int from)
{
if (debug_lvl <= 0) return;
if (debug_lvl & 1) { // Standard console startup message output
if (from == 0) { // Constructor
}
if (from == 2) { // After thruster loading
cout << " X = " << Thruster->GetLocationX() << endl;
cout << " Y = " << Thruster->GetLocationY() << endl;
cout << " Z = " << Thruster->GetLocationZ() << endl;
cout << " Pitch = " << radtodeg*Thruster->GetAnglesToBody(ePitch) << " degrees" << endl;
cout << " Yaw = " << radtodeg*Thruster->GetAnglesToBody(eYaw) << " degrees" << endl;
}
}
if (debug_lvl & 2 ) { // Instantiation/Destruction notification
if (from == 0) cout << "Instantiated: FGEngine" << endl;
if (from == 1) cout << "Destroyed: FGEngine" << endl;
}
if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
}
if (debug_lvl & 8 ) { // Runtime state variables
}
if (debug_lvl & 16) { // Sanity checking
}
if (debug_lvl & 64) {
if (from == 0) { // Constructor
cout << IdSrc << endl;
cout << IdHdr << endl;
}
}
}
}