Header: FGAtmosphere.h
Author: Jon Berndt
- Implementation of 1959 Standard Atmosphere added by Tony Peden
- Date started: 11/24/98
+ Date started: 6/2011
- ------------- Copyright (C) 1999 Jon S. Berndt (jon@jsbsim.org) -------------
+ ------------- Copyright (C) 2011 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
HISTORY
--------------------------------------------------------------------------------
-11/24/98 JSB Created
-07/23/99 TP Added implementation of 1959 Standard Atmosphere
- Moved calculation of Mach number to FGPropagate
- Updated to '76 model
+5/2011 JSB Created
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
SENTRY
INCLUDES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-#include "FGModel.h"
-#include "math/FGColumnVector3.h"
-#include "math/FGTable.h"
+#include <vector>
+#include "models/FGModel.h"
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
DEFINITIONS
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-#define ID_ATMOSPHERE "$Id: FGAtmosphere.h,v 1.24 2010/11/18 12:38:06 jberndt Exp $"
+#define ID_ATMOSPHERE "$Id: FGAtmosphere.h,v 1.30 2012/04/13 13:18:28 jberndt Exp $"
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FORWARD DECLARATIONS
CLASS DOCUMENTATION
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
-/** Models the 1976 Standard Atmosphere.
- @author Tony Peden, Jon Berndt
- @version $Id: FGAtmosphere.h,v 1.24 2010/11/18 12:38:06 jberndt Exp $
- @see Anderson, John D. "Introduction to Flight, Third Edition", McGraw-Hill,
- 1989, ISBN 0-07-001641-0
-
- Additionally, various turbulence models are available. They are specified
- via the property <tt>atmosphere/turb-type</tt>. The following models are
- available:
- - 0: ttNone (turbulence disabled)
- - 1: ttStandard
- - 2: ttBerndt
- - 3: ttCulp
- - 4: ttMilspec (Dryden spectrum)
- - 5: ttTustin (Dryden spectrum)
-
- The Milspec and Tustin models are described in the Yeager report cited below.
- They both use a Dryden spectrum model whose parameters (scale lengths and intensities)
- are modelled according to MIL-F-8785C. Parameters are modelled differently
- for altitudes below 1000ft and above 2000ft, for altitudes in between they
- are interpolated linearly.
-
- The two models differ in the implementation of the transfer functions
- described in the milspec.
-
- To use one of these two models, set <tt>atmosphere/turb-type</tt> to 4 resp. 5,
- and specify values for <tt>atmosphere/turbulence/milspec/windspeed_at_20ft_AGL-fps<tt>
- and <tt>atmosphere/turbulence/milspec/severity<tt> (the latter corresponds to
- the probability of exceedence curves from Fig. 7 of the milspec, allowable
- range is 0 (disabled) to 7). <tt>atmosphere/psiw-rad</tt> is respected as well;
- note that you have to specify a positive wind magnitude to prevent psiw from
- being reset to zero.
-
- Reference values (cf. figures 7 and 9 from the milspec):
- <table>
- <tr><td><b>Intensity</b></td>
- <td><b><tt>windspeed_at_20ft_AGL-fps</tt></b></td>
- <td><b><tt>severity</tt></b></td></tr>
- <tr><td>light</td>
- <td>25 (15 knots)</td>
- <td>3</td></tr>
- <tr><td>moderate</td>
- <td>50 (30 knots)</td>
- <td>4</td></tr>
- <tr><td>severe</td>
- <td>75 (45 knots)</td>
- <td>6</td></tr>
- </table>
-
- @see Yeager, Jessie C.: "Implementation and Testing of Turbulence Models for
- the F18-HARV" (<a
- href="http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980028448_1998081596.pdf">
- pdf</a>), NASA CR-1998-206937, 1998
-
- @see MIL-F-8785C: Military Specification: Flying Qualities of Piloted Aircraft
-
+/** Models an empty, abstract base atmosphere class.
+
+ <h2> Properties </h2>
+ @property atmosphere/T-R The current modeled temperature in degrees Rankine.
+ @property atmosphere/rho-slugs_ft3
+ @property atmosphere/P-psf
+ @property atmosphere/a-fps
+ @property atmosphere/T-sl-R
+ @property atmosphere/rho-sl-slugs_ft3
+ @property atmosphere/P-sl-psf
+ @property atmosphere/a-sl-fps
+ @property atmosphere/theta
+ @property atmosphere/sigma
+ @property atmosphere/delta
+ @property atmosphere/a-ratio
+
+ @author Jon Berndt
+ @version $Id: FGAtmosphere.h,v 1.30 2012/04/13 13:18:28 jberndt Exp $
*/
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
class FGAtmosphere : public FGModel {
public:
+ /// Enums for specifying temperature units.
+ enum eTemperature {eNoTempUnit=0, eFahrenheit, eCelsius, eRankine, eKelvin};
+
+ /// Enums for specifying pressure units.
+ enum ePressure {eNoPressUnit=0, ePSF, eMillibars, ePascals, eInchesHg};
+
/// Constructor
FGAtmosphere(FGFDMExec*);
+
/// Destructor
- ~FGAtmosphere();
- /** Runs the Atmosphere model; called by the Executive
+ virtual ~FGAtmosphere();
+
+ /** Runs the atmosphere forces model; called by the Executive.
+ Can pass in a value indicating if the executive is directing the simulation to Hold.
+ @param Holding if 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.
@return false if no error */
- bool Run(void);
+ bool Run(bool Holding);
+
bool InitModel(void);
- enum tType {ttNone, ttStandard, ttBerndt, ttCulp, ttMilspec, ttTustin} turbType;
- /// Returns the temperature in degrees Rankine.
- double GetTemperature(void) const {return *temperature;}
- /** Returns the density in slugs/ft^3.
- <i>This function may <b>only</b> be used if Run() is called first.</i> */
- double GetDensity(void) const {return *density;}
+ // *************************************************************************
+ /// @name Temperature access functions.
+ /// There are several ways to get the temperature, and several modeled temperature
+ /// values that can be retrieved.
+ // @{
+ /// Returns the actual, modeled temperature at the current altitude in degrees Rankine.
+ /// @return Modeled temperature in degrees Rankine.
+ virtual double GetTemperature() const {return Temperature;}
+
+ /// Returns the actual modeled temperature in degrees Rankine at a specified altitude.
+ /// @param altitude The altitude above sea level (ASL) in feet.
+ /// @return Modeled temperature in degrees Rankine at the specified altitude.
+ virtual double GetTemperature(double altitude) const = 0;
+
+ /// Returns the actual, modeled sea level temperature in degrees Rankine.
+ /// @return The modeled temperature in degrees Rankine at sea level.
+ virtual double GetTemperatureSL() const { return GetTemperature(0.0); }
+
+ /// Returns the ratio of the at-current-altitude temperature as modeled
+ /// over the sea level value.
+ virtual double GetTemperatureRatio() const { return GetTemperature()*rSLtemperature; }
+
+ /// Returns the ratio of the temperature as modeled at the supplied altitude
+ /// over the sea level value.
+ virtual double GetTemperatureRatio(double h) const { return GetTemperature(h)*rSLtemperature; }
+
+ /// Sets the Sea Level temperature.
+ /// @param t the temperature value in the unit provided.
+ /// @param unit the unit of the temperature.
+ virtual void SetTemperatureSL(double t, eTemperature unit=eFahrenheit);
+
+ /// Sets the temperature at the supplied altitude.
+ /// @param t The temperature value in the unit provided.
+ /// @param h The altitude in feet above sea level.
+ /// @param unit The unit of the temperature.
+ virtual void SetTemperature(double t, double h, eTemperature unit=eFahrenheit) = 0;
+ //@}
+
+ // *************************************************************************
+ /// @name Pressure access functions.
+ //@{
/// Returns the pressure in psf.
- double GetPressure(void) const {return *pressure;}
- /// Returns the standard pressure at a specified altitude
- double GetPressure(double altitude);
- /// Returns the standard temperature at a specified altitude
- double GetTemperature(double altitude);
- /// Returns the standard density at a specified altitude
- double GetDensity(double altitude);
- /// Returns the speed of sound in ft/sec.
- double GetSoundSpeed(void) const {return soundspeed;}
- /// Returns the absolute viscosity.
- double GetAbsoluteViscosity(void) const {return intViscosity;}
- /// Returns the kinematic viscosity.
- double GetKinematicViscosity(void) const {return intKinematicViscosity;}
+ virtual double GetPressure(void) const {return Pressure;}
+
+ /// Returns the pressure at a specified altitude in psf.
+ virtual double GetPressure(double altitude) const = 0;
- /// Returns the sea level temperature in degrees Rankine.
- double GetTemperatureSL(void) const { return SLtemperature; }
- /// Returns the sea level density in slugs/ft^3
- double GetDensitySL(void) const { return SLdensity; }
/// Returns the sea level pressure in psf.
- double GetPressureSL(void) const { return SLpressure; }
- /// Returns the sea level speed of sound in ft/sec.
- double GetSoundSpeedSL(void) const { return SLsoundspeed; }
+ virtual double GetPressureSL(void) const { return SLpressure; }
- /// Returns the ratio of at-altitude temperature over the sea level value.
- double GetTemperatureRatio(void) const { return (*temperature)*rSLtemperature; }
- /// Returns the ratio of at-altitude density over the sea level value.
- double GetDensityRatio(void) const { return (*density)*rSLdensity; }
/// Returns the ratio of at-altitude pressure over the sea level value.
- double GetPressureRatio(void) const { return (*pressure)*rSLpressure; }
- /// Returns the ratio of at-altitude sound speed over the sea level value.
- double GetSoundSpeedRatio(void) const { return soundspeed*rSLsoundspeed; }
-
- /// Tells the simulator to use an externally calculated atmosphere model.
- void UseExternal(void);
- /// Tells the simulator to use the internal atmosphere model.
- void UseInternal(void); //this is the default
- /// Gets the boolean that tells if the external atmosphere model is being used.
- bool External(void) { return useExternal; }
-
- /// Provides the external atmosphere model with an interface to set the temperature.
- void SetExTemperature(double t) { exTemperature=t; }
- /// Provides the external atmosphere model with an interface to set the density.
- void SetExDensity(double d) { exDensity=d; }
- /// Provides the external atmosphere model with an interface to set the pressure.
- void SetExPressure(double p) { exPressure=p; }
-
- /// Sets the temperature deviation at sea-level in degrees Fahrenheit
- void SetSLTempDev(double d) { T_dev_sl = d; }
- /// Gets the temperature deviation at sea-level in degrees Fahrenheit
- double GetSLTempDev(void) const { return T_dev_sl; }
- /// Sets the current delta-T in degrees Fahrenheit
- void SetDeltaT(double d) { delta_T = d; }
- /// Gets the current delta-T in degrees Fahrenheit
- double GetDeltaT(void) const { return delta_T; }
- /// Gets the at-altitude temperature deviation in degrees Fahrenheit
- double GetTempDev(void) const { return T_dev; }
- /// Gets the density altitude in feet
- double GetDensityAltitude(void) const { return density_altitude; }
-
- // TOTAL WIND access functions (wind + gust + turbulence)
-
- /// Retrieves the total wind components in NED frame.
- const FGColumnVector3& GetTotalWindNED(void) const { return vTotalWindNED; }
-
- /// Retrieves a total wind component in NED frame.
- double GetTotalWindNED(int idx) const {return vTotalWindNED(idx);}
-
- // WIND access functions
-
- /// Sets the wind components in NED frame.
- void SetWindNED(double wN, double wE, double wD) { vWindNED(1)=wN; vWindNED(2)=wE; vWindNED(3)=wD;}
-
- /// Sets a wind component in NED frame.
- void SetWindNED(int idx, double wind) { vWindNED(idx)=wind;}
-
- /// Retrieves the wind components in NED frame.
- FGColumnVector3& GetWindNED(void) { return vWindNED; }
-
- /// Retrieves a wind component in NED frame.
- double GetWindNED(int idx) const {return vWindNED(idx);}
-
- /** Retrieves the direction that the wind is coming from.
- The direction is defined as north=0 and increases counterclockwise.
- The wind heading is returned in radians.*/
- double GetWindPsi(void) const { return psiw; }
-
- /** Sets the direction that the wind is coming from.
- The direction is defined as north=0 and increases counterclockwise to 2*pi (radians). The
- vertical component of wind is assumed to be zero - and is forcibly set to zero. This function
- sets the vWindNED vector components based on the supplied direction. The magnitude of
- the wind set in the vector is preserved (assuming the vertical component is non-zero).
- @param dir wind direction in the horizontal plane, in radians.*/
- void SetWindPsi(double dir);
+ virtual double GetPressureRatio(void) const { return Pressure*rSLpressure; }
+
+ /** Sets the sea level pressure for modeling.
+ @param pressure The pressure in the units specified.
+ @param unit the unit of measure that the specified pressure is
+ supplied in.*/
+ virtual void SetPressureSL(ePressure unit, double pressure);
+ //@}
+
+ // *************************************************************************
+ /// @name Density access functions.
+ //@{
+ /** Returns the density in slugs/ft^3.
+ This function may only be used if Run() is called first. */
+ virtual double GetDensity(void) const {return Density;}
- void SetWindspeed(double speed);
+ /** Returns the density in slugs/ft^3 at a given altitude in ft. */
+ virtual double GetDensity(double altitude) const;
- double GetWindspeed(void) const;
+ /// Returns the sea level density in slugs/ft^3
+ virtual double GetDensitySL(void) const { return SLdensity; }
- // GUST access functions
+ /// Returns the ratio of at-altitude density over the sea level value.
+ virtual double GetDensityRatio(void) const { return Density*rSLdensity; }
+ //@}
- /// Sets a gust component in NED frame.
- void SetGustNED(int idx, double gust) { vGustNED(idx)=gust;}
+ // *************************************************************************
+ /// @name Speed of sound access functions.
+ //@{
+ /// Returns the speed of sound in ft/sec.
+ virtual double GetSoundSpeed(void) const {return Soundspeed;}
- /// Sets a turbulence component in NED frame.
- void SetTurbNED(int idx, double turb) { vTurbulenceNED(idx)=turb;}
+ /// Returns the sea level speed of sound in ft/sec.
+ virtual double GetSoundSpeedSL(void) const { return SLsoundspeed; }
- /// Sets the gust components in NED frame.
- void SetGustNED(double gN, double gE, double gD) { vGustNED(eNorth)=gN; vGustNED(eEast)=gE; vGustNED(eDown)=gD;}
+ /// Returns the ratio of at-altitude sound speed over the sea level value.
+ virtual double GetSoundSpeedRatio(void) const { return Soundspeed*rSLsoundspeed; }
+ //@}
- /// Retrieves a gust component in NED frame.
- double GetGustNED(int idx) const {return vGustNED(idx);}
+ // *************************************************************************
+ /// @name Viscosity access functions.
+ //@{
+ /// Returns the absolute viscosity.
+ virtual double GetAbsoluteViscosity(void) const {return Viscosity;}
- /// Retrieves a turbulence component in NED frame.
- double GetTurbNED(int idx) const {return vTurbulenceNED(idx);}
+ /// Returns the kinematic viscosity.
+ virtual double GetKinematicViscosity(void) const {return KinematicViscosity;}
+ //@}
- /// Retrieves the gust components in NED frame.
- FGColumnVector3& GetGustNED(void) {return vGustNED;}
+ virtual double GetDensityAltitude() const {return DensityAltitude;}
- /** Turbulence models available: ttNone, ttStandard, ttBerndt, ttCulp, ttMilspec, ttTustin */
- void SetTurbType(tType tt) {turbType = tt;}
- tType GetTurbType() const {return turbType;}
+ virtual double GetPressureAltitude() const {return PressureAltitude;}
- void SetTurbGain(double tg) {TurbGain = tg;}
- double GetTurbGain() const {return TurbGain;}
+ struct Inputs {
+ double altitudeASL;
+ } in;
- void SetTurbRate(double tr) {TurbRate = tr;}
- double GetTurbRate() const {return TurbRate;}
+protected:
+ double SLtemperature, SLdensity, SLpressure, SLsoundspeed; // Sea level conditions
+ double Temperature, Density, Pressure, Soundspeed; // Current actual conditions at altitude
+ double rSLtemperature, rSLdensity, rSLpressure, rSLsoundspeed; // Reciprocal of sea level conditions
- void SetRhythmicity(double r) {Rhythmicity=r;}
- double GetRhythmicity() const {return Rhythmicity;}
+ double PressureAltitude;
+ double DensityAltitude;
- double GetTurbPQR(int idx) const {return vTurbPQR(idx);}
- double GetTurbMagnitude(void) const {return Magnitude;}
- const FGColumnVector3& GetTurbDirection(void) const {return vDirection;}
- const FGColumnVector3& GetTurbPQR(void) const {return vTurbPQR;}
+ const double SutherlandConstant, Beta;
+ double Viscosity, KinematicViscosity;
- void SetWindspeed20ft(double ws) { windspeed_at_20ft = ws;}
- double GetWindspeed20ft() const { return windspeed_at_20ft;}
+ /// Calculate the atmosphere for the given altitude.
+ void Calculate(double altitude);
- /// allowable range: 0-7, 3=light, 4=moderate, 6=severe turbulence
- void SetProbabilityOfExceedence( int idx) {probability_of_exceedence_index = idx;}
- int GetProbabilityOfExceedence() const { return probability_of_exceedence_index;}
+ // Converts to Rankine from one of several unit systems.
+ virtual double ConvertToRankine(double t, eTemperature unit) const;
+
+ // Converts to PSF (pounds per square foot) from one of several unit systems.
+ virtual double ConvertToPSF(double t, ePressure unit=ePSF) const;
-protected:
- double rho;
-
- struct atmType {double Temperature; double Pressure; double Density;};
- int lastIndex;
- double h;
- double htab[8];
- double StdSLtemperature,StdSLdensity,StdSLpressure,StdSLsoundspeed;
- double rSLtemperature,rSLdensity,rSLpressure,rSLsoundspeed; //reciprocals
- double SLtemperature,SLdensity,SLpressure,SLsoundspeed;
- double *temperature, *density, *pressure;
- double soundspeed;
- bool useExternal;
- double exTemperature,exDensity,exPressure;
- double intTemperature, intDensity, intPressure;
- double SutherlandConstant, Beta, intViscosity, intKinematicViscosity;
- double T_dev_sl, T_dev, delta_T, density_altitude;
- atmType atmosphere;
- bool StandardTempOnly;
- bool first_pass;
-
- double MagnitudedAccelDt, MagnitudeAccel, Magnitude;
- double TurbGain;
- double TurbRate;
- double Rhythmicity;
- double wind_from_clockwise;
- double spike, target_time, strength;
- FGColumnVector3 vDirectiondAccelDt;
- FGColumnVector3 vDirectionAccel;
- FGColumnVector3 vDirection;
- FGColumnVector3 vTurbulenceGrad;
- FGColumnVector3 vBodyTurbGrad;
- FGColumnVector3 vTurbPQR;
-
- // Dryden turbulence model
- double windspeed_at_20ft; ///< in ft/s
- int probability_of_exceedence_index; ///< this is bound as the severity property
- FGTable *POE_Table; ///< probability of exceedence table
-
- double psiw;
- FGColumnVector3 vTotalWindNED;
- FGColumnVector3 vWindNED;
- FGColumnVector3 vGustNED;
- FGColumnVector3 vTurbulenceNED;
-
- /// Calculate the atmosphere for the given altitude, including effects of temperature deviation.
- void Calculate(double altitude);
- /// Calculate atmospheric properties other than the basic T, P and rho.
- void CalculateDerived(void);
- /// Get T, P and rho for a standard atmosphere at the given altitude.
- void GetStdAtmosphere(double altitude);
- void Turbulence(void);
- void bind(void);
+ virtual void bind(void);
void Debug(int from);
};
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