bool FGAircraft::Load(Element* el)
{
string element_name;
Element* element;
if (!FGModel::Load(el)) return false;
if (el->FindElement("wingarea"))
WingArea = el->FindElementValueAsNumberConvertTo("wingarea", "FT2");
if (el->FindElement("wingspan"))
WingSpan = el->FindElementValueAsNumberConvertTo("wingspan", "FT");
if (el->FindElement("chord"))
cbar = el->FindElementValueAsNumberConvertTo("chord", "FT");
if (el->FindElement("wing_incidence"))
WingIncidence = el->FindElementValueAsNumberConvertTo("wing_incidence", "RAD");
if (el->FindElement("htailarea"))
HTailArea = el->FindElementValueAsNumberConvertTo("htailarea", "FT2");
if (el->FindElement("htailarm"))
HTailArm = el->FindElementValueAsNumberConvertTo("htailarm", "FT");
if (el->FindElement("vtailarea"))
VTailArea = el->FindElementValueAsNumberConvertTo("vtailarea", "FT2");
if (el->FindElement("vtailarm"))
VTailArm = el->FindElementValueAsNumberConvertTo("vtailarm", "FT");
if (el->FindElement("pitot_angle"))
PitotAngle = el->FindElementValueAsNumberConvertTo("pitot_angle", "RAD");
// Find all LOCATION elements that descend from this METRICS branch of the
// config file. This would be CG location, eyepoint, etc.
element = el->FindElement("location");
while (element) {
element_name = element->GetAttributeValue("name");
if (element_name == "AERORP") vXYZrp = element->FindElementTripletConvertTo("IN");
else if (element_name == "EYEPOINT") vXYZep = element->FindElementTripletConvertTo("IN");
else if (element_name == "VRP") vXYZvrp = element->FindElementTripletConvertTo("IN");
element = el->FindNextElement("location");
}
// calculate some derived parameters
if (cbar != 0.0) {
lbarh = HTailArm/cbar;
lbarv = VTailArm/cbar;
if (WingArea != 0.0) {
vbarh = HTailArm*HTailArea / (cbar*WingArea);
vbarv = VTailArm*VTailArea / (WingSpan*WingArea);
}
}
PostLoad(el, PropertyManager);
Debug(2);
return true;
}
bool FGFDMExec::ReadChild(Element* el)
{
// Add a new childData object to the child FDM list
// Populate that childData element with a new FDMExec object
// Set the IsChild flag for that FDMExec object
// Get the aircraft name
// set debug level to print out no additional data for child objects
// Load the model given the aircraft name
// reset debug level to prior setting
string token;
struct childData* child = new childData;
child->exec = new FGFDMExec(Root, FDMctr);
child->exec->SetChild(true);
string childAircraft = el->GetAttributeValue("name");
string sMated = el->GetAttributeValue("mated");
if (sMated == "false") child->mated = false; // child objects are mated by default.
string sInternal = el->GetAttributeValue("internal");
if (sInternal == "true") child->internal = true; // child objects are external by default.
child->exec->SetAircraftPath( AircraftPath );
child->exec->SetEnginePath( EnginePath );
child->exec->SetSystemsPath( SystemsPath );
child->exec->LoadModel(childAircraft);
Element* location = el->FindElement("location");
if (location) {
child->Loc = location->FindElementTripletConvertTo("IN");
} else {
cerr << endl << highint << fgred << " No location was found for this child object!" << reset << endl;
exit(-1);
}
Element* orientation = el->FindElement("orient");
if (orientation) {
child->Orient = orientation->FindElementTripletConvertTo("RAD");
} else if (debug_lvl > 0) {
cerr << endl << highint << " No orientation was found for this child object! Assuming 0,0,0." << reset << endl;
}
ChildFDMList.push_back(child);
return true;
}
bool FGMassBalance::Load(Element* document)
{
string element_name = "";
Name = "Mass Properties Model: " + document->GetAttributeValue("name");
// Perform base class Pre-Load
if (!FGModel::Load(document))
return false;
SetAircraftBaseInertias(ReadInertiaMatrix(document));
if (document->FindElement("emptywt")) {
EmptyWeight = document->FindElementValueAsNumberConvertTo("emptywt", "LBS");
}
Element *element = document->FindElement("location");
while (element) {
element_name = element->GetAttributeValue("name");
if (element_name == "CG") vbaseXYZcg = element->FindElementTripletConvertTo("IN");
element = document->FindNextElement("location");
}
// Find all POINTMASS elements that descend from this METRICS branch of the
// config file.
element = document->FindElement("pointmass");
while (element) {
AddPointMass(element);
element = document->FindNextElement("pointmass");
}
double ChildFDMWeight = 0.0;
for (int fdm=0; fdm<FDMExec->GetFDMCount(); fdm++) {
if (FDMExec->GetChildFDM(fdm)->mated) ChildFDMWeight += FDMExec->GetChildFDM(fdm)->exec->GetMassBalance()->GetWeight();
}
Weight = EmptyWeight + in.TanksWeight + GetTotalPointMassWeight()
+ in.GasMass*slugtolb + ChildFDMWeight;
Mass = lbtoslug*Weight;
PostLoad(document, PropertyManager);
Debug(2);
return true;
}
FGThruster::FGThruster(FGFDMExec *FDMExec, Element *el, int num ): FGForce(FDMExec)
{
Element* thruster_element = el->GetParent();
Element* element;
FGColumnVector3 location, orientation, pointing;
Type = ttDirect;
SetTransformType(FGForce::tCustom);
Name = el->GetAttributeValue("name");
GearRatio = 1.0;
ReverserAngle = 0.0;
Thrust = 0.0;
EngineNum = num;
PropertyManager = FDMExec->GetPropertyManager();
// Determine the initial location and orientation of this thruster and load the
// thruster with this information.
element = thruster_element->FindElement("location");
if (element) location = element->FindElementTripletConvertTo("IN");
else cerr << fgred << " No thruster location found." << reset << endl;
SetLocation(location);
string property_name, base_property_name;
base_property_name = CreateIndexedPropertyName("propulsion/engine", EngineNum);
element = thruster_element->FindElement("pointing");
if (element) {
// This defines a fixed nozzle that has no public interface property to gimbal or reverse it.
pointing = element->FindElementTripletConvertTo("RAD"); // The specification of RAD here is superfluous,
// and simply precludes a conversion.
mT.InitMatrix();
mT(1,1) = pointing(1);
mT(2,1) = pointing(2);
mT(3,1) = pointing(3);
} else {
element = thruster_element->FindElement("orient");
if (element) orientation = element->FindElementTripletConvertTo("RAD");
SetAnglesToBody(orientation);
property_name = base_property_name + "/pitch-angle-rad";
PropertyManager->Tie( property_name.c_str(), (FGForce *)this, &FGForce::GetPitch, &FGForce::SetPitch);
property_name = base_property_name + "/yaw-angle-rad";
PropertyManager->Tie( property_name.c_str(), (FGForce *)this, &FGForce::GetYaw, &FGForce::SetYaw);
if (el->GetName() == "direct") // this is a direct thruster. At this time
// only a direct thruster can be reversed.
{
property_name = base_property_name + "/reverser-angle-rad";
PropertyManager->Tie( property_name.c_str(), (FGThruster *)this, &FGThruster::GetReverserAngle,
&FGThruster::SetReverserAngle);
}
}
Debug(0);
}
FGTank::FGTank(FGFDMExec* exec, Element* el, int tank_number)
: TankNumber(tank_number)
{
string token, strFuelName;
Element* element;
Element* element_Grain;
FGPropertyManager *PropertyManager = exec->GetPropertyManager();
Area = 1.0;
Density = 6.6;
InitialTemperature = Temperature = -9999.0;
Ixx = Iyy = Izz = 0.0;
InertiaFactor = 1.0;
Radius = Contents = Standpipe = Length = InnerRadius = 0.0;
ExternalFlow = 0.0;
InitialStandpipe = 0.0;
Capacity = 0.00001;
Priority = InitialPriority = 1;
vXYZ.InitMatrix();
vXYZ_drain.InitMatrix();
ixx_unit = iyy_unit = izz_unit = 1.0;
grainType = gtUNKNOWN; // This is the default
type = el->GetAttributeValue("type");
if (type == "FUEL") Type = ttFUEL;
else if (type == "OXIDIZER") Type = ttOXIDIZER;
else Type = ttUNKNOWN;
element = el->FindElement("location");
if (element) vXYZ = element->FindElementTripletConvertTo("IN");
else cerr << "No location found for this tank." << endl;
vXYZ_drain = vXYZ; // Set initial drain location to initial tank CG
element = el->FindElement("drain_location");
if (element) {
vXYZ_drain = element->FindElementTripletConvertTo("IN");
}
if (el->FindElement("radius"))
Radius = el->FindElementValueAsNumberConvertTo("radius", "IN");
if (el->FindElement("inertia_factor"))
InertiaFactor = el->FindElementValueAsNumber("inertia_factor");
if (el->FindElement("capacity"))
Capacity = el->FindElementValueAsNumberConvertTo("capacity", "LBS");
if (el->FindElement("contents"))
InitialContents = Contents = el->FindElementValueAsNumberConvertTo("contents", "LBS");
if (el->FindElement("temperature"))
InitialTemperature = Temperature = el->FindElementValueAsNumber("temperature");
if (el->FindElement("standpipe"))
InitialStandpipe = Standpipe = el->FindElementValueAsNumberConvertTo("standpipe", "LBS");
if (el->FindElement("priority"))
InitialPriority = Priority = (int)el->FindElementValueAsNumber("priority");
if (el->FindElement("density"))
Density = el->FindElementValueAsNumberConvertTo("density", "LBS/GAL");
if (el->FindElement("type"))
strFuelName = el->FindElementValue("type");
SetPriority( InitialPriority ); // this will also set the Selected flag
if (Capacity == 0) {
cerr << "Tank capacity must not be zero. Reset to 0.00001 lbs!" << endl;
Capacity = 0.00001;
Contents = 0.0;
}
if (Contents > Capacity) {
cerr << "Tank content (" << Contents << " lbs) is greater than tank capacity ("
<< Capacity << " lbs) for tank " << tank_number
<< "! Did you accidentally swap contents and capacity?" << endl;
throw("tank definition error");
}
PctFull = 100.0*Contents/Capacity; // percent full; 0 to 100.0
// Check whether this is a solid propellant "tank". Initialize it if true.
element_Grain = el->FindElement("grain_config");
if (element_Grain) {
strGType = element_Grain->GetAttributeValue("type");
if (strGType == "CYLINDRICAL") grainType = gtCYLINDRICAL;
else if (strGType == "ENDBURNING") grainType = gtENDBURNING;
else if (strGType == "FUNCTION") {
grainType = gtFUNCTION;
if (element_Grain->FindElement("ixx") != 0) {
Element* element_ixx = element_Grain->FindElement("ixx");
if (element_ixx->GetAttributeValue("unit") == "KG*M2") ixx_unit = 1.0/1.35594;
if (element_ixx->FindElement("function") != 0) {
function_ixx = new FGFunction(PropertyManager, element_ixx->FindElement("function"));
}
} else {
throw("For tank "+to_string(TankNumber)+" and when grain_config is specified an ixx must be specified when the FUNCTION grain type is specified.");
}
if (element_Grain->FindElement("iyy")) {
Element* element_iyy = element_Grain->FindElement("iyy");
if (element_iyy->GetAttributeValue("unit") == "KG*M2") iyy_unit = 1.0/1.35594;
if (element_iyy->FindElement("function") != 0) {
function_iyy = new FGFunction(PropertyManager, element_iyy->FindElement("function"));
}
} else {
throw("For tank "+to_string(TankNumber)+" and when grain_config is specified an iyy must be specified when the FUNCTION grain type is specified.");
}
if (element_Grain->FindElement("izz")) {
Element* element_izz = element_Grain->FindElement("izz");
if (element_izz->GetAttributeValue("unit") == "KG*M2") izz_unit = 1.0/1.35594;
if (element_izz->FindElement("function") != 0) {
function_izz = new FGFunction(PropertyManager, element_izz->FindElement("function"));
}
} else {
throw("For tank "+to_string(TankNumber)+" and when grain_config is specified an izz must be specified when the FUNCTION grain type is specified.");
}
}
else cerr << "Unknown propellant grain type specified" << endl;
if (element_Grain->FindElement("length"))
Length = element_Grain->FindElementValueAsNumberConvertTo("length", "IN");
if (element_Grain->FindElement("bore_diameter"))
InnerRadius = element_Grain->FindElementValueAsNumberConvertTo("bore_diameter", "IN")/2.0;
// Initialize solid propellant values for debug and runtime use.
switch (grainType) {
case gtCYLINDRICAL:
if (Radius <= InnerRadius) {
std::stringstream error;
error << "The bore diameter should be smaller than the total grain diameter!" << endl;
throw std::runtime_error(error.str());
}
Volume = M_PI * Length * (Radius*Radius - InnerRadius*InnerRadius); // cubic inches
break;
case gtENDBURNING:
Volume = M_PI * Length * Radius * Radius; // cubic inches
break;
case gtFUNCTION:
Volume = 1; // Volume is irrelevant for the FUNCTION type, but it can't be zero!
break;
case gtUNKNOWN:
std::stringstream error;
error << "Unknown grain type found in this rocket engine definition." << endl;
throw std::runtime_error(error.str());
}
Density = (Contents*lbtoslug)/Volume; // slugs/in^3
}
CalculateInertias();
if (Temperature != -9999.0) InitialTemperature = Temperature = FahrenheitToCelsius(Temperature);
Area = 40.0 * pow(Capacity/1975, 0.666666667);
// A named fuel type will override a previous density value
if (!strFuelName.empty()) Density = ProcessFuelName(strFuelName);
bind(PropertyManager);
Debug(0);
}
FGTank::FGTank(FGFDMExec* exec, Element* el, int tank_number)
: TankNumber(tank_number), Exec(exec)
{
string token, strFuelName;
Element* element;
Element* element_Grain;
Area = 1.0;
Density = 6.6;
InitialTemperature = Temperature = -9999.0;
Ixx = Iyy = Izz = 0.0;
InertiaFactor = 1.0;
Radius = Contents = Standpipe = Length = InnerRadius = 0.0;
PreviousUsed = 0.0;
ExternalFlow = 0.0;
InitialStandpipe = 0.0;
Capacity = 0.00001;
Priority = InitialPriority = 1;
PropertyManager = Exec->GetPropertyManager();
vXYZ.InitMatrix();
vXYZ_drain.InitMatrix();
type = el->GetAttributeValue("type");
if (type == "FUEL") Type = ttFUEL;
else if (type == "OXIDIZER") Type = ttOXIDIZER;
else Type = ttUNKNOWN;
element = el->FindElement("location");
if (element) vXYZ = element->FindElementTripletConvertTo("IN");
else cerr << "No location found for this tank." << endl;
vXYZ_drain = vXYZ; // Set initial drain location to initial tank CG
element = el->FindElement("drain_location");
if (element) {
vXYZ_drain = element->FindElementTripletConvertTo("IN");
}
if (el->FindElement("radius"))
Radius = el->FindElementValueAsNumberConvertTo("radius", "IN");
if (el->FindElement("inertia_factor"))
InertiaFactor = el->FindElementValueAsNumber("inertia_factor");
if (el->FindElement("capacity"))
Capacity = el->FindElementValueAsNumberConvertTo("capacity", "LBS");
if (el->FindElement("contents"))
InitialContents = Contents = el->FindElementValueAsNumberConvertTo("contents", "LBS");
if (el->FindElement("temperature"))
InitialTemperature = Temperature = el->FindElementValueAsNumber("temperature");
if (el->FindElement("standpipe"))
InitialStandpipe = Standpipe = el->FindElementValueAsNumberConvertTo("standpipe", "LBS");
if (el->FindElement("priority"))
InitialPriority = Priority = (int)el->FindElementValueAsNumber("priority");
if (el->FindElement("density"))
Density = el->FindElementValueAsNumberConvertTo("density", "LBS/GAL");
if (el->FindElement("type"))
strFuelName = el->FindElementValue("type");
SetPriority( InitialPriority ); // this will also set the Selected flag
if (Capacity == 0) {
cerr << "Tank capacity must not be zero. Reset to 0.00001 lbs!" << endl;
Capacity = 0.00001;
Contents = 0.0;
}
if (Contents > Capacity) {
cerr << "Tank content (" << Contents << " lbs) is greater than tank capacity ("
<< Capacity << " lbs) for tank " << tank_number
<< "! Did you accidentally swap contents and capacity?" << endl;
throw("tank definition error");
}
PctFull = 100.0*Contents/Capacity; // percent full; 0 to 100.0
// Check whether this is a solid propellant "tank". Initialize it if true.
grainType = gtUNKNOWN; // This is the default
element_Grain = el->FindElement("grain_config");
if (element_Grain) {
strGType = element_Grain->GetAttributeValue("type");
if (strGType == "CYLINDRICAL") grainType = gtCYLINDRICAL;
else if (strGType == "ENDBURNING") grainType = gtENDBURNING;
else cerr << "Unknown propellant grain type specified" << endl;
if (element_Grain->FindElement("length"))
Length = element_Grain->FindElementValueAsNumberConvertTo("length", "IN");
if (element_Grain->FindElement("bore_diameter"))
InnerRadius = element_Grain->FindElementValueAsNumberConvertTo("bore_diameter", "IN")/2.0;
// Initialize solid propellant values for debug and runtime use.
switch (grainType) {
case gtCYLINDRICAL:
if (Radius <= InnerRadius) {
cerr << "The bore diameter should be smaller than the total grain diameter!" << endl;
exit(-1);
}
Volume = M_PI * Length * (Radius*Radius - InnerRadius*InnerRadius); // cubic inches
break;
case gtENDBURNING:
Volume = M_PI * Length * Radius * Radius; // cubic inches
break;
case gtUNKNOWN:
cerr << "Unknown grain type found in this rocket engine definition." << endl;
exit(-1);
}
Density = (Contents*lbtoslug)/Volume; // slugs/in^3
}
CalculateInertias();
string property_name, base_property_name;
base_property_name = CreateIndexedPropertyName("propulsion/tank", TankNumber);
property_name = base_property_name + "/contents-lbs";
PropertyManager->Tie( property_name.c_str(), (FGTank*)this, &FGTank::GetContents,
&FGTank::SetContents );
property_name = base_property_name + "/pct-full";
PropertyManager->Tie( property_name.c_str(), (FGTank*)this, &FGTank::GetPctFull);
property_name = base_property_name + "/priority";
PropertyManager->Tie( property_name.c_str(), (FGTank*)this, &FGTank::GetPriority,
&FGTank::SetPriority );
property_name = base_property_name + "/external-flow-rate-pps";
PropertyManager->Tie( property_name.c_str(), (FGTank*)this, &FGTank::GetExternalFlow,
&FGTank::SetExternalFlow );
if (Temperature != -9999.0) InitialTemperature = Temperature = FahrenheitToCelsius(Temperature);
Area = 40.0 * pow(Capacity/1975, 0.666666667);
// A named fuel type will override a previous density value
if (!strFuelName.empty()) Density = ProcessFuelName(strFuelName);
Debug(0);
}
bool FGMassBalance::Load(Element* elem)
{
string element_name = "";
double bixx, biyy, bizz, bixy, bixz, biyz;
string fname="", file="";
string separator = "/";
fname = elem->GetAttributeValue("file");
if (!fname.empty()) {
file = FDMExec->GetFullAircraftPath() + separator + fname;
document = LoadXMLDocument(file);
if (document == 0L) return false;
} else {
document = elem;
}
FGModel::Load(document); // Perform base class Load.
bixx = biyy = bizz = bixy = bixz = biyz = 0.0;
if (document->FindElement("ixx"))
bixx = document->FindElementValueAsNumberConvertTo("ixx", "SLUG*FT2");
if (document->FindElement("iyy"))
biyy = document->FindElementValueAsNumberConvertTo("iyy", "SLUG*FT2");
if (document->FindElement("izz"))
bizz = document->FindElementValueAsNumberConvertTo("izz", "SLUG*FT2");
if (document->FindElement("ixy"))
bixy = document->FindElementValueAsNumberConvertTo("ixy", "SLUG*FT2");
if (document->FindElement("ixz"))
bixz = document->FindElementValueAsNumberConvertTo("ixz", "SLUG*FT2");
if (document->FindElement("iyz"))
biyz = document->FindElementValueAsNumberConvertTo("iyz", "SLUG*FT2");
SetAircraftBaseInertias(FGMatrix33( bixx, -bixy, bixz,
-bixy, biyy, -biyz,
bixz, -biyz, bizz ));
if (document->FindElement("emptywt")) {
EmptyWeight = document->FindElementValueAsNumberConvertTo("emptywt", "LBS");
}
Element *element = document->FindElement("location");
while (element) {
element_name = element->GetAttributeValue("name");
if (element_name == "CG") vbaseXYZcg = element->FindElementTripletConvertTo("IN");
element = document->FindNextElement("location");
}
// Find all POINTMASS elements that descend from this METRICS branch of the
// config file.
element = document->FindElement("pointmass");
while (element) {
AddPointMass(element);
element = document->FindNextElement("pointmass");
}
double ChildFDMWeight = 0.0;
for (int fdm=0; fdm<FDMExec->GetFDMCount(); fdm++) {
if (FDMExec->GetChildFDM(fdm)->mated) ChildFDMWeight += FDMExec->GetChildFDM(fdm)->exec->GetMassBalance()->GetWeight();
}
Weight = EmptyWeight + in.TanksWeight + GetTotalPointMassWeight()
+ in.GasMass*slugtolb + ChildFDMWeight;
Mass = lbtoslug*Weight;
PostLoad(document, PropertyManager);
Debug(2);
return true;
}
FGGasCell::FGGasCell(FGFDMExec* exec, Element* el, unsigned int num,
const struct Inputs& input)
: FGForce(exec), in(input)
{
string token;
Element* element;
FGPropertyManager* PropertyManager = exec->GetPropertyManager();
MassBalance = exec->GetMassBalance();
gasCellJ = FGMatrix33();
gasCellM = FGColumnVector3();
Buoyancy = MaxVolume = MaxOverpressure = Temperature = Pressure =
Contents = Volume = dVolumeIdeal = 0.0;
Xradius = Yradius = Zradius = Xwidth = Ywidth = Zwidth = 0.0;
ValveCoefficient = ValveOpen = 0.0;
CellNum = num;
// NOTE: In the local system X points north, Y points east and Z points down.
SetTransformType(FGForce::tLocalBody);
type = el->GetAttributeValue("type");
if (type == "HYDROGEN") Type = ttHYDROGEN;
else if (type == "HELIUM") Type = ttHELIUM;
else if (type == "AIR") Type = ttAIR;
else Type = ttUNKNOWN;
element = el->FindElement("location");
if (element) {
vXYZ = element->FindElementTripletConvertTo("IN");
} else {
std::stringstream error;
error << "Fatal Error: No location found for this gas cell." << endl;
throw std::runtime_error(error.str());
}
if ((el->FindElement("x_radius") || el->FindElement("x_width")) &&
(el->FindElement("y_radius") || el->FindElement("y_width")) &&
(el->FindElement("z_radius") || el->FindElement("z_width"))) {
if (el->FindElement("x_radius")) {
Xradius = el->FindElementValueAsNumberConvertTo("x_radius", "FT");
}
if (el->FindElement("y_radius")) {
Yradius = el->FindElementValueAsNumberConvertTo("y_radius", "FT");
}
if (el->FindElement("z_radius")) {
Zradius = el->FindElementValueAsNumberConvertTo("z_radius", "FT");
}
if (el->FindElement("x_width")) {
Xwidth = el->FindElementValueAsNumberConvertTo("x_width", "FT");
}
if (el->FindElement("y_width")) {
Ywidth = el->FindElementValueAsNumberConvertTo("y_width", "FT");
}
if (el->FindElement("z_width")) {
Zwidth = el->FindElementValueAsNumberConvertTo("z_width", "FT");
}
// The volume is a (potentially) extruded ellipsoid.
// However, currently only a few combinations of radius and width are
// fully supported.
if ((Xradius != 0.0) && (Yradius != 0.0) && (Zradius != 0.0) &&
(Xwidth == 0.0) && (Ywidth == 0.0) && (Zwidth == 0.0)) {
// Ellipsoid volume.
MaxVolume = 4.0 * M_PI * Xradius * Yradius * Zradius / 3.0;
} else if ((Xradius == 0.0) && (Yradius != 0.0) && (Zradius != 0.0) &&
(Xwidth != 0.0) && (Ywidth == 0.0) && (Zwidth == 0.0)) {
// Cylindrical volume.
MaxVolume = M_PI * Yradius * Zradius * Xwidth;
} else {
cerr << "Warning: Unsupported gas cell shape." << endl;
MaxVolume =
(4.0 * M_PI * Xradius * Yradius * Zradius / 3.0 +
M_PI * Yradius * Zradius * Xwidth +
M_PI * Xradius * Zradius * Ywidth +
M_PI * Xradius * Yradius * Zwidth +
2.0 * Xradius * Ywidth * Zwidth +
2.0 * Yradius * Xwidth * Zwidth +
2.0 * Zradius * Xwidth * Ywidth +
Xwidth * Ywidth * Zwidth);
}
} else {
std::stringstream error;
error << "Fatal Error: Gas cell shape must be given." << endl;
throw std::runtime_error(error.str());
}
if (el->FindElement("max_overpressure")) {
MaxOverpressure = el->FindElementValueAsNumberConvertTo("max_overpressure",
"LBS/FT2");
}
if (el->FindElement("fullness")) {
const double Fullness = el->FindElementValueAsNumber("fullness");
if (0 <= Fullness) {
Volume = Fullness * MaxVolume;
} else {
cerr << "Warning: Invalid initial gas cell fullness value." << endl;
}
}
if (el->FindElement("valve_coefficient")) {
ValveCoefficient =
el->FindElementValueAsNumberConvertTo("valve_coefficient",
"FT4*SEC/SLUG");
ValveCoefficient = max(ValveCoefficient, 0.0);
}
// Initialize state
SetLocation(vXYZ);
if (Temperature == 0.0) {
Temperature = in.Temperature;
}
if (Pressure == 0.0) {
Pressure = in.Pressure;
}
if (Volume != 0.0) {
// Calculate initial gas content.
Contents = Pressure * Volume / (R * Temperature);
// Clip to max allowed value.
const double IdealPressure = Contents * R * Temperature / MaxVolume;
if (IdealPressure > Pressure + MaxOverpressure) {
Contents = (Pressure + MaxOverpressure) * MaxVolume / (R * Temperature);
Pressure = Pressure + MaxOverpressure;
} else {
Pressure = max(IdealPressure, Pressure);
}
} else {
// Calculate initial gas content.
Contents = Pressure * MaxVolume / (R * Temperature);
}
Volume = Contents * R * Temperature / Pressure;
Mass = Contents * M_gas();
// Bind relevant properties
string property_name, base_property_name;
base_property_name = CreateIndexedPropertyName("buoyant_forces/gas-cell", CellNum);
property_name = base_property_name + "/max_volume-ft3";
PropertyManager->Tie( property_name.c_str(), &MaxVolume, false );
PropertyManager->GetNode()->SetWritable( property_name, false );
property_name = base_property_name + "/temp-R";
PropertyManager->Tie( property_name.c_str(), &Temperature, false );
property_name = base_property_name + "/pressure-psf";
PropertyManager->Tie( property_name.c_str(), &Pressure, false );
property_name = base_property_name + "/volume-ft3";
PropertyManager->Tie( property_name.c_str(), &Volume, false );
property_name = base_property_name + "/buoyancy-lbs";
PropertyManager->Tie( property_name.c_str(), &Buoyancy, false );
property_name = base_property_name + "/contents-mol";
PropertyManager->Tie( property_name.c_str(), &Contents, false );
property_name = base_property_name + "/valve_open";
PropertyManager->Tie( property_name.c_str(), &ValveOpen, false );
Debug(0);
// Read heat transfer coefficients
if (Element* heat = el->FindElement("heat")) {
Element* function_element = heat->FindElement("function");
while (function_element) {
HeatTransferCoeff.push_back(new FGFunction(PropertyManager,
function_element));
function_element = heat->FindNextElement("function");
}
}
// Load ballonets if there are any
if (Element* ballonet_element = el->FindElement("ballonet")) {
while (ballonet_element) {
Ballonet.push_back(new FGBallonet(exec,
ballonet_element,
Ballonet.size(),
this, in));
ballonet_element = el->FindNextElement("ballonet");
}
}
}
FGBallonet::FGBallonet(FGFDMExec* exec, Element* el, unsigned int num,
FGGasCell* parent, const struct FGGasCell::Inputs& input)
: in(input)
{
string token;
Element* element;
FGPropertyManager* PropertyManager = exec->GetPropertyManager();
MassBalance = exec->GetMassBalance();
ballonetJ = FGMatrix33();
MaxVolume = MaxOverpressure = Temperature = Pressure =
Contents = Volume = dVolumeIdeal = dU = 0.0;
Xradius = Yradius = Zradius = Xwidth = Ywidth = Zwidth = 0.0;
ValveCoefficient = ValveOpen = 0.0;
BlowerInput = NULL;
CellNum = num;
Parent = parent;
// NOTE: In the local system X points north, Y points east and Z points down.
element = el->FindElement("location");
if (element) {
vXYZ = element->FindElementTripletConvertTo("IN");
} else {
std::stringstream error;
error << "Fatal Error: No location found for this ballonet." << endl;
throw std::runtime_error(error.str());
}
if ((el->FindElement("x_radius") || el->FindElement("x_width")) &&
(el->FindElement("y_radius") || el->FindElement("y_width")) &&
(el->FindElement("z_radius") || el->FindElement("z_width"))) {
if (el->FindElement("x_radius")) {
Xradius = el->FindElementValueAsNumberConvertTo("x_radius", "FT");
}
if (el->FindElement("y_radius")) {
Yradius = el->FindElementValueAsNumberConvertTo("y_radius", "FT");
}
if (el->FindElement("z_radius")) {
Zradius = el->FindElementValueAsNumberConvertTo("z_radius", "FT");
}
if (el->FindElement("x_width")) {
Xwidth = el->FindElementValueAsNumberConvertTo("x_width", "FT");
}
if (el->FindElement("y_width")) {
Ywidth = el->FindElementValueAsNumberConvertTo("y_width", "FT");
}
if (el->FindElement("z_width")) {
Zwidth = el->FindElementValueAsNumberConvertTo("z_width", "FT");
}
// The volume is a (potentially) extruded ellipsoid.
// FIXME: However, currently only a few combinations of radius and
// width are fully supported.
if ((Xradius != 0.0) && (Yradius != 0.0) && (Zradius != 0.0) &&
(Xwidth == 0.0) && (Ywidth == 0.0) && (Zwidth == 0.0)) {
// Ellipsoid volume.
MaxVolume = 4.0 * M_PI * Xradius * Yradius * Zradius / 3.0;
} else if ((Xradius == 0.0) && (Yradius != 0.0) && (Zradius != 0.0) &&
(Xwidth != 0.0) && (Ywidth == 0.0) && (Zwidth == 0.0)) {
// Cylindrical volume.
MaxVolume = M_PI * Yradius * Zradius * Xwidth;
} else {
cerr << "Warning: Unsupported ballonet shape." << endl;
MaxVolume =
(4.0 * M_PI * Xradius * Yradius * Zradius / 3.0 +
M_PI * Yradius * Zradius * Xwidth +
M_PI * Xradius * Zradius * Ywidth +
M_PI * Xradius * Yradius * Zwidth +
2.0 * Xradius * Ywidth * Zwidth +
2.0 * Yradius * Xwidth * Zwidth +
2.0 * Zradius * Xwidth * Ywidth +
Xwidth * Ywidth * Zwidth);
}
} else {
std::stringstream error;
error << "Fatal Error: Ballonet shape must be given." << endl;
throw std::runtime_error(error.str());
}
if (el->FindElement("max_overpressure")) {
MaxOverpressure = el->FindElementValueAsNumberConvertTo("max_overpressure",
"LBS/FT2");
}
if (el->FindElement("fullness")) {
const double Fullness = el->FindElementValueAsNumber("fullness");
if (0 <= Fullness) {
Volume = Fullness * MaxVolume;
} else {
cerr << "Warning: Invalid initial ballonet fullness value." << endl;
}
}
if (el->FindElement("valve_coefficient")) {
ValveCoefficient =
el->FindElementValueAsNumberConvertTo("valve_coefficient",
"FT4*SEC/SLUG");
ValveCoefficient = max(ValveCoefficient, 0.0);
}
// Initialize state
if (Temperature == 0.0) {
Temperature = Parent->GetTemperature();
}
if (Pressure == 0.0) {
Pressure = Parent->GetPressure();
}
if (Volume != 0.0) {
// Calculate initial air content.
Contents = Pressure * Volume / (R * Temperature);
// Clip to max allowed value.
const double IdealPressure = Contents * R * Temperature / MaxVolume;
if (IdealPressure > Pressure + MaxOverpressure) {
Contents = (Pressure + MaxOverpressure) * MaxVolume / (R * Temperature);
Pressure = Pressure + MaxOverpressure;
} else {
Pressure = max(IdealPressure, Pressure);
}
} else {
// Calculate initial air content.
Contents = Pressure * MaxVolume / (R * Temperature);
}
Volume = Contents * R * Temperature / Pressure;
// Bind relevant properties
string property_name, base_property_name;
base_property_name = CreateIndexedPropertyName("buoyant_forces/gas-cell", Parent->GetIndex());
base_property_name = CreateIndexedPropertyName(base_property_name + "/ballonet", CellNum);
property_name = base_property_name + "/max_volume-ft3";
PropertyManager->Tie( property_name, &MaxVolume, false );
PropertyManager->GetNode()->SetWritable( property_name, false );
property_name = base_property_name + "/temp-R";
PropertyManager->Tie( property_name, &Temperature, false );
property_name = base_property_name + "/pressure-psf";
PropertyManager->Tie( property_name, &Pressure, false );
property_name = base_property_name + "/volume-ft3";
PropertyManager->Tie( property_name, &Volume, false );
property_name = base_property_name + "/contents-mol";
PropertyManager->Tie( property_name, &Contents, false );
property_name = base_property_name + "/valve_open";
PropertyManager->Tie( property_name, &ValveOpen, false );
Debug(0);
// Read heat transfer coefficients
if (Element* heat = el->FindElement("heat")) {
Element* function_element = heat->FindElement("function");
while (function_element) {
HeatTransferCoeff.push_back(new FGFunction(PropertyManager,
function_element));
function_element = heat->FindNextElement("function");
}
}
// Read blower input function
if (Element* blower = el->FindElement("blower_input")) {
Element* function_element = blower->FindElement("function");
BlowerInput = new FGFunction(PropertyManager,
function_element);
}
}
