FGRotor::FGRotor(FGFDMExec *exec, Element* rotor_element, int num)
: FGThruster(exec, rotor_element, num)
{
FGColumnVector3 location, orientation;
Element *thruster_element;
PropertyManager = fdmex->GetPropertyManager();
dt = fdmex->GetDeltaT();
/* apply defaults */
rho = 0.002356; // just a sane value
RPM = 0.0;
Sense = 1.0;
tailRotorPresent = false;
effective_tail_col = 0.001; // just a sane value
prop_inflow_ratio_lambda = 0.0;
prop_advance_ratio_mu = 0.0;
prop_inflow_ratio_induced_nu = 0.0;
prop_mr_torque = 0.0;
prop_thrust_coefficient = 0.0;
prop_coning_angle = 0.0;
prop_theta_downwash = prop_phi_downwash = 0.0;
hover_threshold = 0.0;
hover_scale = 0.0;
mr.zero();
tr.zero();
// debug stuff
prop_DumpFlag = 0;
/* configure */
Type = ttRotor;
SetTransformType(FGForce::tCustom);
// get data from parent and 'mount' the rotor system
thruster_element = rotor_element->GetParent()->FindElement("sense");
if (thruster_element) {
Sense = thruster_element->GetDataAsNumber() >= 0.0 ? 1.0: -1.0;
}
thruster_element = rotor_element->GetParent()->FindElement("location");
if (thruster_element) location = thruster_element->FindElementTripletConvertTo("IN");
else cerr << "No thruster location found." << endl;
thruster_element = rotor_element->GetParent()->FindElement("orient");
if (thruster_element) orientation = thruster_element->FindElementTripletConvertTo("RAD");
else cerr << "No thruster orientation found." << endl;
SetLocation(location);
SetAnglesToBody(orientation);
// get main rotor parameters
mr.parent = rotor_element;
int flags = eMain;
string a_val="";
a_val = rotor_element->GetAttributeValue("variant");
if ( a_val == "coaxial" ) {
flags += eCoaxial;
cerr << "# found 'coaxial' variant" << endl;
}
if (Sense<0.0) {
flags += eRotCW;
}
mr.configure(flags);
mr.rk.init(0,dt,6);
// get tail rotor parameters
tr.parent=rotor_element->FindElement("tailrotor");
if (tr.parent) {
tailRotorPresent = true;
} else {
tailRotorPresent = false;
cerr << "# No tailrotor found, assuming a single rotor." << endl;
}
if (tailRotorPresent) {
int flags = eTail;
if (Sense<0.0) {
flags += eRotCW;
}
tr.configure(flags, &mr);
tr.rk.init(0,dt,6);
tr.RpmRatio = tr.NominalRPM/mr.NominalRPM; // 'connect'
}
/* remaining parameters */
// ground effect
double c_ground_effect = 0.0; // uh1 ~ 0.28 , larger values increase the effect
ground_effect_exp = 0.0;
ground_effect_shift = 0.0;
if (rotor_element->FindElement("cgroundeffect"))
c_ground_effect = rotor_element->FindElementValueAsNumber("cgroundeffect");
if (rotor_element->FindElement("groundeffectshift"))
ground_effect_shift = rotor_element->FindElementValueAsNumberConvertTo("groundeffectshift","FT");
// prepare calculations, see /TA77/
if (c_ground_effect > 1e-5) {
ground_effect_exp = 1.0 / ( 2.0*mr.Radius * c_ground_effect );
} else {
ground_effect_exp = 0.0; // disable
}
// smooth out jumps in hagl reported, otherwise the ground effect
// calculation would cause jumps too. 1Hz seems sufficient.
damp_hagl = Filter(1.0,dt);
// misc, experimental
if (rotor_element->FindElement("hoverthreshold"))
hover_threshold = rotor_element->FindElementValueAsNumberConvertTo("hoverthreshold", "FT/SEC");
if (rotor_element->FindElement("hoverscale"))
hover_scale = rotor_element->FindElementValueAsNumber("hoverscale");
// enable import-export
bind();
// unused right now
prop_rotorbrake->setDoubleValue(0.0);
prop_freewheel_factor->setDoubleValue(1.0);
Debug(0);
} // Constructor
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);
}
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");
}
}
}
