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JSBSim::FGAerodynamics Class Reference

Encapsulates the aerodynamic calculations. More...

#include <FGAerodynamics.h>

Inherits JSBSim::FGModel.

Classes

struct  Inputs
 

Public Member Functions

 FGAerodynamics (FGFDMExec *Executive)
 Constructor.
 
 ~FGAerodynamics () override
 Destructor.
 
bool InitModel (void) override
 
bool Run (bool Holding) override
 Runs the Aerodynamics model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold.
 
bool Load (Element *element) override
 Loads the Aerodynamics model.
 
const FGColumnVector3GetForces (void) const
 Gets the total aerodynamic force vector.
 
double GetForces (int n) const
 Gets the aerodynamic force for an axis.
 
const FGColumnVector3GetMoments (void) const
 Gets the total aerodynamic moment vector about the CG.
 
double GetMoments (int n) const
 Gets the aerodynamic moment about the CG for an axis.
 
const FGColumnVector3GetMomentsMRC (void) const
 Gets the total aerodynamic moment vector about the Moment Reference Center.
 
double GetMomentsMRC (int n) const
 Gets the aerodynamic moment about the Moment Reference Center for an axis.
 
const FGColumnVector3GetvFw (void) const
 Retrieves the aerodynamic forces in the wind axes.
 
double GetvFw (int axis) const
 Retrieves the aerodynamic forces in the wind axes, given an axis.
 
FGColumnVector3 GetForcesInStabilityAxes (void) const
 Retrieves the aerodynamic forces in the stability axes.
 
double GetForcesInStabilityAxes (int n) const
 Retrieves the aerodynamic forces in the stability axes, given an axis.
 
FGColumnVector3 GetMomentsInStabilityAxes (void) const
 Gets the total aerodynamic moment vector about the CG in the stability axes.
 
double GetMomentsInStabilityAxes (int n) const
 Gets the aerodynamic moment about the CG for an axis.
 
FGColumnVector3 GetMomentsInWindAxes (void) const
 Gets the total aerodynamic moment vector about the CG in the wind axes.
 
double GetMomentsInWindAxes (int n) const
 Gets the aerodynamic moment about the CG for an axis.
 
double GetLoD (void) const
 Retrieves the lift over drag ratio.
 
double GetClSquared (void) const
 Retrieves the square of the lift coefficient.
 
double GetAlphaCLMax (void) const
 
double GetAlphaCLMin (void) const
 
double GetHysteresisParm (void) const
 
double GetStallWarn (void) const
 
double GetAlphaW (void) const
 
double GetBI2Vel (void) const
 
double GetCI2Vel (void) const
 
void SetAlphaCLMax (double tt)
 
void SetAlphaCLMin (double tt)
 
std::string GetAeroFunctionStrings (const std::string &delimeter) const
 Gets the strings for the current set of aero functions.
 
std::string GetAeroFunctionValues (const std::string &delimeter) const
 Gets the aero function values.
 
std::vector< FGFunction * > * GetAeroFunctions (void) const
 
- Public Member Functions inherited from JSBSim::FGModel
 FGModel (FGFDMExec *)
 Constructor.
 
 ~FGModel () override
 Destructor.
 
bool InitModel (void) override
 
void SetRate (unsigned int tt)
 Set the ouput rate for the model in frames.
 
unsigned int GetRate (void)
 Get the output rate for the model in frames.
 
FGFDMExecGetExec (void)
 
void SetPropertyManager (FGPropertyManager *fgpm)
 
virtual SGPath FindFullPathName (const SGPath &path) const
 
const std::string & GetName (void)
 
- Public Member Functions inherited from JSBSim::FGModelFunctions
virtual ~FGModelFunctions ()
 
void RunPreFunctions (void)
 
void RunPostFunctions (void)
 
bool Load (Element *el, FGFDMExec *fdmex, std::string prefix="")
 
void PreLoad (Element *el, FGFDMExec *fdmex, std::string prefix="")
 
void PostLoad (Element *el, FGFDMExec *fdmex, std::string prefix="")
 
std::string GetFunctionStrings (const std::string &delimeter) const
 Gets the strings for the current set of functions.
 
std::string GetFunctionValues (const std::string &delimeter) const
 Gets the function values.
 
FGFunctionGetPreFunction (const std::string &name)
 Get one of the "pre" function.
 
- Public Member Functions inherited from JSBSim::FGJSBBase
 FGJSBBase ()
 Constructor for FGJSBBase.
 
virtual ~FGJSBBase ()
 Destructor for FGJSBBase.
 
void PutMessage (const Message &msg)
 Places a Message structure on the Message queue.
 
void PutMessage (const std::string &text)
 Creates a message with the given text and places it on the queue.
 
void PutMessage (const std::string &text, bool bVal)
 Creates a message with the given text and boolean value and places it on the queue.
 
void PutMessage (const std::string &text, int iVal)
 Creates a message with the given text and integer value and places it on the queue.
 
void PutMessage (const std::string &text, double dVal)
 Creates a message with the given text and double value and places it on the queue.
 
int SomeMessages (void) const
 Reads the message on the queue (but does not delete it).
 
void ProcessMessage (void)
 Reads the message on the queue and removes it from the queue.
 
MessageProcessNextMessage (void)
 Reads the next message on the queue and removes it from the queue.
 
void disableHighLighting (void)
 Disables highlighting in the console output.
 

Public Attributes

struct JSBSim::FGAerodynamics::Inputs in
 

Additional Inherited Members

- Public Types inherited from JSBSim::FGJSBBase
enum  { eL = 1 , eM , eN }
 Moments L, M, N. More...
 
enum  { eP = 1 , eQ , eR }
 Rates P, Q, R. More...
 
enum  { eU = 1 , eV , eW }
 Velocities U, V, W. More...
 
enum  { eX = 1 , eY , eZ }
 Positions X, Y, Z. More...
 
enum  { ePhi = 1 , eTht , ePsi }
 Euler angles Phi, Theta, Psi. More...
 
enum  { eDrag = 1 , eSide , eLift }
 Stability axis forces, Drag, Side force, Lift. More...
 
enum  { eRoll = 1 , ePitch , eYaw }
 Local frame orientation Roll, Pitch, Yaw. More...
 
enum  { eNorth = 1 , eEast , eDown }
 Local frame position North, East, Down. More...
 
enum  { eLat = 1 , eLong , eRad }
 Locations Radius, Latitude, Longitude. More...
 
enum  {
  inNone = 0 , inDegrees , inRadians , inMeters ,
  inFeet
}
 Conversion specifiers. More...
 
static const std::string & GetVersion (void)
 Returns the version number of JSBSim.
 
static constexpr double KelvinToFahrenheit (double kelvin)
 Converts from degrees Kelvin to degrees Fahrenheit.
 
static constexpr double CelsiusToRankine (double celsius)
 Converts from degrees Celsius to degrees Rankine.
 
static constexpr double RankineToCelsius (double rankine)
 Converts from degrees Rankine to degrees Celsius.
 
static constexpr double KelvinToRankine (double kelvin)
 Converts from degrees Kelvin to degrees Rankine.
 
static constexpr double RankineToKelvin (double rankine)
 Converts from degrees Rankine to degrees Kelvin.
 
static constexpr double FahrenheitToCelsius (double fahrenheit)
 Converts from degrees Fahrenheit to degrees Celsius.
 
static constexpr double CelsiusToFahrenheit (double celsius)
 Converts from degrees Celsius to degrees Fahrenheit.
 
static constexpr double CelsiusToKelvin (double celsius)
 Converts from degrees Celsius to degrees Kelvin.
 
static constexpr double KelvinToCelsius (double kelvin)
 Converts from degrees Kelvin to degrees Celsius.
 
static constexpr double FeetToMeters (double measure)
 Converts from feet to meters.
 
static double PitotTotalPressure (double mach, double p)
 Compute the total pressure in front of the Pitot tube.
 
static double MachFromImpactPressure (double qc, double p)
 Compute the Mach number from the differential pressure (qc) and the static pressure.
 
static double VcalibratedFromMach (double mach, double p)
 Calculate the calibrated airspeed from the Mach number.
 
static double MachFromVcalibrated (double vcas, double p)
 Calculate the Mach number from the calibrated airspeed.Based on the formulas in the US Air Force Aircraft Performance Flight Testing Manual (AFFTC-TIH-99-01).
 
static bool EqualToRoundoff (double a, double b)
 Finite precision comparison.
 
static bool EqualToRoundoff (float a, float b)
 Finite precision comparison.
 
static bool EqualToRoundoff (float a, double b)
 Finite precision comparison.
 
static bool EqualToRoundoff (double a, float b)
 Finite precision comparison.
 
static constexpr double Constrain (double min, double value, double max)
 Constrain a value between a minimum and a maximum value.
 
static constexpr double sign (double num)
 
static double GaussianRandomNumber (void)
 
- Static Public Attributes inherited from JSBSim::FGJSBBase
static char highint [5] = {27, '[', '1', 'm', '\0' }
 highlights text
 
static char halfint [5] = {27, '[', '2', 'm', '\0' }
 low intensity text
 
static char normint [6] = {27, '[', '2', '2', 'm', '\0' }
 normal intensity text
 
static char reset [5] = {27, '[', '0', 'm', '\0' }
 resets text properties
 
static char underon [5] = {27, '[', '4', 'm', '\0' }
 underlines text
 
static char underoff [6] = {27, '[', '2', '4', 'm', '\0' }
 underline off
 
static char fgblue [6] = {27, '[', '3', '4', 'm', '\0' }
 blue text
 
static char fgcyan [6] = {27, '[', '3', '6', 'm', '\0' }
 cyan text
 
static char fgred [6] = {27, '[', '3', '1', 'm', '\0' }
 red text
 
static char fggreen [6] = {27, '[', '3', '2', 'm', '\0' }
 green text
 
static char fgdef [6] = {27, '[', '3', '9', 'm', '\0' }
 default text
 
static short debug_lvl = 1
 
- Protected Member Functions inherited from JSBSim::FGModel
bool Upload (Element *el, bool preLoad)
 Uploads this model in memory.
 
static std::string CreateIndexedPropertyName (const std::string &Property, int index)
 
- Protected Attributes inherited from JSBSim::FGModel
unsigned int exe_ctr
 
unsigned int rate
 
std::string Name
 
FGFDMExecFDMExec
 
FGPropertyManagerPropertyManager
 
- Protected Attributes inherited from JSBSim::FGModelFunctions
std::vector< FGFunction * > PreFunctions
 
std::vector< FGFunction * > PostFunctions
 
FGPropertyReader LocalProperties
 
static Message localMsg
 
static std::queue< MessageMessages
 
static unsigned int messageId = 0
 
static constexpr double radtodeg = 180. / 3.14159265358979323846
 
static constexpr double degtorad = 3.14159265358979323846 / 180.
 
static constexpr double hptoftlbssec = 550.0
 
static constexpr double psftoinhg = 0.014138
 
static constexpr double psftopa = 47.88
 
static constexpr double ktstofps = 1.68781
 
static constexpr double fpstokts = 1.0 / ktstofps
 
static constexpr double inchtoft = 1.0/12.0
 
static constexpr double fttom = 0.3048
 
static constexpr double m3toft3 = 1.0/(fttom*fttom*fttom)
 
static constexpr double in3tom3 = inchtoft*inchtoft*inchtoft/m3toft3
 
static constexpr double inhgtopa = 3386.38
 
static constexpr double slugtolb = 32.174049
 Note that definition of lbtoslug by the inverse of slugtolb and not to a different constant you can also get from some tables will make lbtoslug*slugtolb == 1 up to the magnitude of roundoff.
 
static constexpr double lbtoslug = 1.0/slugtolb
 
static constexpr double kgtolb = 2.20462
 
static constexpr double kgtoslug = 0.06852168
 
static const std::string needed_cfg_version = "2.0"
 
static const std::string JSBSim_version = JSBSIM_VERSION " " __DATE__ " " __TIME__
 
static int gaussian_random_number_phase = 0
 

Detailed Description

Encapsulates the aerodynamic calculations.

This class owns and contains the list of force/coefficients that define the aerodynamic properties of an aircraft. Here also, such unique phenomena as ground effect, aerodynamic reference point shift, and maximum lift curve tailoff are handled.

Configuration File Format for <aerodynamics> Section:

<aerodynamics>
<alphalimits unit="{RAD | DEG}">
<min> {number} </min>
<max> {number} </max>
</alphalimits>
<hysteresis_limits unit="{RAD | DEG}">
<min> {number} </min>
<max> {number} </max>
</hysteresis_limits>
<aero_ref_pt_shift_x>
<function>
{function contents}
</function>
</aero_ref_pt_shift_x>
<function>
{function contents}
</function>
<axis name="{LIFT | DRAG | SIDE | ROLL | PITCH | YAW}">
{force or moment definitions}
</axis>
{additional axis definitions}
</aerodynamics>

Optionally two other coordinate systems may be used.

1) Body coordinate system:

<axis name="{X | Y | Z}">


2) Axial-Normal coordinate system:

<axis name="{AXIAL | NORMAL | SIDE}">


Systems may NOT be combined, or a load error will occur.

Author
Jon S. Berndt, Tony Peden
Version
Revision
1.30

Definition at line 94 of file FGAerodynamics.h.

Constructor & Destructor Documentation

◆ FGAerodynamics()

JSBSim::FGAerodynamics::FGAerodynamics ( FGFDMExec * Executive)

Constructor.

Parameters
Executivea pointer to the parent executive object

Definition at line 51 of file FGAerodynamics.cpp.

◆ ~FGAerodynamics()

JSBSim::FGAerodynamics::~FGAerodynamics ( )
override

Destructor.

Definition at line 92 of file FGAerodynamics.cpp.

Member Function Documentation

◆ GetAeroFunctions()

std::vector< FGFunction * > * JSBSim::FGAerodynamics::GetAeroFunctions ( void ) const
inline

Definition at line 216 of file FGAerodynamics.h.

◆ GetAeroFunctionStrings()

string JSBSim::FGAerodynamics::GetAeroFunctionStrings ( const std::string & delimeter) const

Gets the strings for the current set of aero functions.

Parameters
delimetereither a tab or comma string depending on output type
Returns
a string containing the descriptive names for all aero functions

Definition at line 517 of file FGAerodynamics.cpp.

◆ GetAeroFunctionValues()

string JSBSim::FGAerodynamics::GetAeroFunctionValues ( const std::string & delimeter) const

Gets the aero function values.

Parameters
delimetereither a tab or comma string depending on output type
Returns
a string containing the numeric values for the current set of aero functions

Definition at line 549 of file FGAerodynamics.cpp.

◆ GetAlphaCLMax()

double JSBSim::FGAerodynamics::GetAlphaCLMax ( void ) const
inline

Definition at line 192 of file FGAerodynamics.h.

◆ GetAlphaCLMin()

double JSBSim::FGAerodynamics::GetAlphaCLMin ( void ) const
inline

Definition at line 193 of file FGAerodynamics.h.

◆ GetAlphaW()

double JSBSim::FGAerodynamics::GetAlphaW ( void ) const
inline

Definition at line 197 of file FGAerodynamics.h.

◆ GetBI2Vel()

double JSBSim::FGAerodynamics::GetBI2Vel ( void ) const
inline

Definition at line 199 of file FGAerodynamics.h.

◆ GetCI2Vel()

double JSBSim::FGAerodynamics::GetCI2Vel ( void ) const
inline

Definition at line 200 of file FGAerodynamics.h.

◆ GetClSquared()

double JSBSim::FGAerodynamics::GetClSquared ( void ) const
inline

Retrieves the square of the lift coefficient.

Definition at line 191 of file FGAerodynamics.h.

◆ GetForces() [1/2]

double JSBSim::FGAerodynamics::GetForces ( int n) const
inline

Gets the aerodynamic force for an axis.

Parameters
nAxis index. This could be 0, 1, or 2, or one of the axis enums: eX, eY, eZ.
Returns
the force acting on an axis

Definition at line 129 of file FGAerodynamics.h.

◆ GetForces() [2/2]

const FGColumnVector3 & JSBSim::FGAerodynamics::GetForces ( void ) const
inline

Gets the total aerodynamic force vector.

Returns
a force vector reference.

Definition at line 123 of file FGAerodynamics.h.

◆ GetForcesInStabilityAxes() [1/2]

double JSBSim::FGAerodynamics::GetForcesInStabilityAxes ( int n) const
inline

Retrieves the aerodynamic forces in the stability axes, given an axis.

Parameters
axisthe axis to return the force for (eX, eY, eZ).
Returns
a reference to a column vector containing the requested stability axis force.

Definition at line 167 of file FGAerodynamics.h.

◆ GetForcesInStabilityAxes() [2/2]

FGColumnVector3 JSBSim::FGAerodynamics::GetForcesInStabilityAxes ( void ) const

Retrieves the aerodynamic forces in the stability axes.

Returns
a reference to a column vector containing the stability axis forces.

Definition at line 320 of file FGAerodynamics.cpp.

◆ GetHysteresisParm()

double JSBSim::FGAerodynamics::GetHysteresisParm ( void ) const
inline

Definition at line 195 of file FGAerodynamics.h.

◆ GetLoD()

double JSBSim::FGAerodynamics::GetLoD ( void ) const
inline

Retrieves the lift over drag ratio.

Definition at line 188 of file FGAerodynamics.h.

◆ GetMoments() [1/2]

double JSBSim::FGAerodynamics::GetMoments ( int n) const
inline

Gets the aerodynamic moment about the CG for an axis.

Returns
the moment about a single axis (as described also in the similar call to GetForces(int n).

Definition at line 138 of file FGAerodynamics.h.

◆ GetMoments() [2/2]

const FGColumnVector3 & JSBSim::FGAerodynamics::GetMoments ( void ) const
inline

Gets the total aerodynamic moment vector about the CG.

Returns
a moment vector reference.

Definition at line 133 of file FGAerodynamics.h.

◆ GetMomentsInStabilityAxes() [1/2]

double JSBSim::FGAerodynamics::GetMomentsInStabilityAxes ( int n) const
inline

Gets the aerodynamic moment about the CG for an axis.

Returns
the moment about a single axis (as described also in the similar call to GetForces(int n).

Definition at line 176 of file FGAerodynamics.h.

◆ GetMomentsInStabilityAxes() [2/2]

FGColumnVector3 JSBSim::FGAerodynamics::GetMomentsInStabilityAxes ( void ) const
inline

Gets the total aerodynamic moment vector about the CG in the stability axes.

Returns
a moment vector reference.

Definition at line 171 of file FGAerodynamics.h.

◆ GetMomentsInWindAxes() [1/2]

double JSBSim::FGAerodynamics::GetMomentsInWindAxes ( int n) const
inline

Gets the aerodynamic moment about the CG for an axis.

Returns
the moment about a single axis (as described also in the similar call to GetForces(int n).

Definition at line 185 of file FGAerodynamics.h.

◆ GetMomentsInWindAxes() [2/2]

FGColumnVector3 JSBSim::FGAerodynamics::GetMomentsInWindAxes ( void ) const
inline

Gets the total aerodynamic moment vector about the CG in the wind axes.

Returns
a moment vector reference.

Definition at line 180 of file FGAerodynamics.h.

◆ GetMomentsMRC() [1/2]

double JSBSim::FGAerodynamics::GetMomentsMRC ( int n) const
inline

Gets the aerodynamic moment about the Moment Reference Center for an axis.

Returns
the moment about a single axis (as described also in the similar call to GetForces(int n).

Definition at line 147 of file FGAerodynamics.h.

◆ GetMomentsMRC() [2/2]

const FGColumnVector3 & JSBSim::FGAerodynamics::GetMomentsMRC ( void ) const
inline

Gets the total aerodynamic moment vector about the Moment Reference Center.

Returns
a moment vector reference.

Definition at line 142 of file FGAerodynamics.h.

◆ GetStallWarn()

double JSBSim::FGAerodynamics::GetStallWarn ( void ) const
inline

Definition at line 196 of file FGAerodynamics.h.

◆ GetvFw() [1/2]

double JSBSim::FGAerodynamics::GetvFw ( int axis) const
inline

Retrieves the aerodynamic forces in the wind axes, given an axis.

Parameters
axisthe axis to return the force for (eX, eY, eZ).
Returns
a reference to a column vector containing the requested wind axis force.

Definition at line 157 of file FGAerodynamics.h.

◆ GetvFw() [2/2]

const FGColumnVector3 & JSBSim::FGAerodynamics::GetvFw ( void ) const
inline

Retrieves the aerodynamic forces in the wind axes.

Returns
a reference to a column vector containing the wind axis forces.

Definition at line 151 of file FGAerodynamics.h.

◆ InitModel()

bool JSBSim::FGAerodynamics::InitModel ( void )
overridevirtual

Reimplemented from JSBSim::FGModelFunctions.

Definition at line 113 of file FGAerodynamics.cpp.

◆ Load()

bool JSBSim::FGAerodynamics::Load ( Element * element)
overridevirtual

Loads the Aerodynamics model.

The Load function for this class expects the XML parser to have found the aerodynamics keyword in the configuration file.

Parameters
elementpointer to the current XML element for aerodynamics parameters.
Returns
true if successful

Reimplemented from JSBSim::FGModel.

Definition at line 331 of file FGAerodynamics.cpp.

◆ Run()

bool JSBSim::FGAerodynamics::Run ( bool Holding)
overridevirtual

Runs the Aerodynamics model; called by the Executive Can pass in a value indicating if the executive is directing the simulation to Hold.

Parameters
Holdingif true, the executive has been directed to hold the sim from advancing time. Some models may ignore this flag, such as the Input model, which may need to be active to listen on a socket for the "Resume" command to be given.
Returns
false if no error

Reimplemented from JSBSim::FGModel.

Definition at line 132 of file FGAerodynamics.cpp.

◆ SetAlphaCLMax()

void JSBSim::FGAerodynamics::SetAlphaCLMax ( double tt)
inline

Definition at line 202 of file FGAerodynamics.h.

◆ SetAlphaCLMin()

void JSBSim::FGAerodynamics::SetAlphaCLMin ( double tt)
inline

Definition at line 203 of file FGAerodynamics.h.

Member Data Documentation

◆ in

struct JSBSim::FGAerodynamics::Inputs JSBSim::FGAerodynamics::in

The documentation for this class was generated from the following files: