FGAtmosphere.h

/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 Header:       FGAtmosphere.h
 Author:       Jon Berndt
 Date started: 6/2011
 
 ------------- 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 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.
 
HISTORY
--------------------------------------------------------------------------------
5/2011   JSB   Created
 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
SENTRY
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#ifndef FGATMOSPHERE_H
#define FGATMOSPHERE_H
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
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#include "models/FGModel.h"
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FORWARD DECLARATIONS
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namespace JSBSim {
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS DOCUMENTATION
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS DECLARATION
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class JSBSIM_API FGAtmosphere : public FGModel {
public:
 
  enum eTemperature {eNoTempUnit=0, eFahrenheit, eCelsius, eRankine, eKelvin};
 
  enum ePressure {eNoPressUnit=0, ePSF, eMillibars, ePascals, eInchesHg};
 
  FGAtmosphere(FGFDMExec*);
 
  virtual ~FGAtmosphere();
 
  bool Run(bool Holding) override;
 
  bool InitModel(void) override;
 
  //  *************************************************************************
  // @{
  virtual double GetTemperature() const {return Temperature;}
 
  virtual double GetTemperature(double altitude) const = 0;
 
  virtual double GetTemperatureSL() const { return SLtemperature; }
 
  virtual double GetTemperatureRatio() const { return GetTemperature()/SLtemperature; }
 
  virtual double GetTemperatureRatio(double h) const { return GetTemperature(h)/SLtemperature; }
 
  virtual void SetTemperatureSL(double t, eTemperature unit=eFahrenheit);
 
  virtual void SetTemperature(double t, double h, eTemperature unit=eFahrenheit) = 0;
 
  //  *************************************************************************
 
 
  virtual double GetPressure(void) const {return Pressure;}
 
  virtual double GetPressure(double altitude) const = 0;
 
  // Returns the sea level pressure in target units, default in psf.
  virtual double GetPressureSL(ePressure to=ePSF) const { return ConvertFromPSF(SLpressure, to);  }
 
  virtual double GetPressureRatio(void) const { return Pressure/SLpressure; }
 
  virtual void SetPressureSL(ePressure unit, double pressure);
 
  //  *************************************************************************
 
 
  virtual double GetDensity(void)  const {return Density;}
 
  virtual double GetDensity(double altitude) const;
 
  virtual double GetDensitySL(void)  const { return SLdensity; }
 
  virtual double GetDensityRatio(void) const { return Density/SLdensity; }
 
  //  *************************************************************************
 
 
  virtual double GetSoundSpeed(void) const {return Soundspeed;}
 
  virtual double GetSoundSpeed(double altitude) const;
 
  virtual double GetSoundSpeedSL(void) const { return SLsoundspeed; }
 
  virtual double GetSoundSpeedRatio(void) const { return Soundspeed/SLsoundspeed; }
 
  //  *************************************************************************
 
 
  virtual double GetAbsoluteViscosity(void) const {return Viscosity;}
 
  virtual double GetKinematicViscosity(void) const {return KinematicViscosity;}
 
  virtual double GetDensityAltitude() const {return DensityAltitude;}
 
  virtual double GetPressureAltitude() const {return PressureAltitude;}
 
  struct Inputs {
    double altitudeASL;
    double GeodLatitudeDeg;
    double LongitudeDeg;
  } in;
 
  static constexpr double StdDaySLtemperature = 518.67;
  static constexpr double StdDaySLpressure = 2116.228;
  const double StdDaySLsoundspeed;
  static constexpr double SHRatio = 1.4;
 
protected:
  // Sea level conditions
  double SLtemperature = 1.8;
  double SLdensity = 1.0;
  double SLpressure = 1.0;
  double SLsoundspeed = 1.0;
  // Current actual conditions at altitude
  double Temperature = 1.8;
  double Density = 0.0;
  double Pressure = 0.0;
  double Soundspeed = 0.0;
  double PressureAltitude = 0.0;
  double DensityAltitude = 0.0;
 
  static constexpr double SutherlandConstant = 198.72;  // deg Rankine
  static constexpr double Beta = 2.269690E-08; // slug/(sec ft R^0.5)
  double Viscosity = 0.0;
  double KinematicViscosity = 0.0;
 
  virtual void Calculate(double altitude);
 
  virtual double CalculateDensityAltitude(double density, double geometricAlt) { return geometricAlt; }
 
  virtual double CalculatePressureAltitude(double pressure, double geometricAlt) { return geometricAlt; }
 
  double ConvertToRankine(double t, eTemperature unit) const;
 
  double ConvertFromRankine(double t, eTemperature unit) const;
 
  double ConvertToPSF(double t, ePressure unit=ePSF) const;
 
  double ConvertFromPSF(double t, ePressure unit=ePSF) const;
 
  double ValidatePressure(double p, const std::string& msg, bool quiet=false) const;
 
  double ValidateTemperature(double t, const std::string& msg, bool quiet=false) const;
 
 
 
  static constexpr double Rstar = 8.31432 * kgtoslug / KelvinToRankine(fttom * fttom);
  static constexpr double Mair = 28.9645 * kgtoslug / 1000.0;
  static constexpr double g0 = 9.80665 / fttom;
  static constexpr double Reng0 = Rstar / Mair;
 
  double Reng = Reng0;
 
  virtual void bind(void);
  void Debug(int from) override;
 
public:
  static constexpr double StdDaySLdensity = StdDaySLpressure / (Reng0 * StdDaySLtemperature);
};
 
} // namespace JSBSim
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
#endif