FGStandardAtmosphere.h

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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
 Header:       FGStandardAtmosphere.h
 Author:       Jon Berndt
 Date started: 5/2011
 
 ------------- 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
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
#ifndef FGSTANDARDATMOSPHERE_H
#define FGSTANDARDATMOSPHERE_H
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
INCLUDES
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#include <vector>
 
#include "math/FGTable.h"
#include "models/FGAtmosphere.h"
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
FORWARD DECLARATIONS
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namespace JSBSim {
 
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS DOCUMENTATION
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
CLASS DECLARATION
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class FGStandardAtmosphere : public FGAtmosphere {
public:
  FGStandardAtmosphere(FGFDMExec*);

  virtual ~FGStandardAtmosphere();
 
  bool InitModel(void) override;
 
  //  *************************************************************************
  // @{
  double GetTemperature(double altitude) const override;

  virtual double GetStdTemperature(double altitude) const;

  virtual double GetStdTemperatureSL() const { return StdSLtemperature; }

  virtual double GetStdTemperatureRatio(double h) const { return GetStdTemperature(h)/StdSLtemperature; }

  virtual double GetTemperatureBias(eTemperature to) const
  { if (to == eCelsius || to == eKelvin) return TemperatureBias/1.80; else return TemperatureBias; }

  virtual double GetTemperatureDeltaGradient(eTemperature to)
  { if (to == eCelsius || to == eKelvin) return TemperatureDeltaGradient/1.80; else return TemperatureDeltaGradient; }

  void SetTemperatureSL(double t, eTemperature unit=eFahrenheit) override;

  void SetTemperature(double t, double h, eTemperature unit=eFahrenheit) override;

  virtual void SetTemperatureBias(eTemperature unit, double t);

  virtual void SetSLTemperatureGradedDelta(eTemperature unit, double t);

  virtual void SetTemperatureGradedDelta(double t, double h, eTemperature unit=eFahrenheit);

  virtual void ResetSLTemperature();
 
  //  *************************************************************************


  double GetPressure(double altitude) const override;

  virtual double GetStdPressure(double altitude) const;

  void SetPressureSL(ePressure unit, double pressure) override;

  virtual void ResetSLPressure();
 
  //  *************************************************************************


  virtual double GetStdDensity(double altitude) const;
 
  //  *************************************************************************


  void SetDewPoint(eTemperature unit, double dewpoint);
  double GetDewPoint(eTemperature to) const;
  void SetVaporPressure(ePressure unit, double Pv);
  double GetVaporPressure(ePressure to) const;
  double GetSaturatedVaporPressure(ePressure to) const;
  void SetRelativeHumidity(double RH);
  double GetRelativeHumidity(void) const;
  void SetVaporMassFractionPPM(double frac);
  double GetVaporMassFractionPPM(void) const;

  virtual void PrintStandardAtmosphereTable();
 
protected:
  double StdSLtemperature, StdSLdensity, StdSLpressure, StdSLsoundspeed;
 
  double TemperatureBias;
  double TemperatureDeltaGradient;
  double GradientFadeoutAltitude;
  double VaporMassFraction;
  double SaturatedVaporPressure;
 
  FGTable StdAtmosTemperatureTable;
  FGTable MaxVaporMassFraction;
  std::vector<double> LapseRates;
  std::vector<double> PressureBreakpoints;
  std::vector<double> StdPressureBreakpoints;
  std::vector<double> StdDensityBreakpoints;
  std::vector<double> StdLapseRates;
 
  void Calculate(double altitude) override;

  void CalculateLapseRates();

  void CalculatePressureBreakpoints(double SLpress);

  void CalculateStdDensityBreakpoints();

  double GeopotentialAltitude(double geometalt) const { return (geometalt * EarthRadius) / (EarthRadius + geometalt); }

  double GeometricAltitude(double geopotalt) const { return (geopotalt * EarthRadius) / (EarthRadius - geopotalt); }

  double CalculateDensityAltitude(double density, double geometricAlt) override;

  double CalculatePressureAltitude(double pressure, double geometricAlt) override;

  double CalculateVaporPressure(double temperature);

  void ValidateVaporMassFraction(double geometricAlt);

  void CalculateSLDensity(void) { SLdensity = SLpressure / (Reng * SLtemperature); }

  void CalculateSLSoundSpeedAndDensity(void);
 
  void bind(void) override;
  void Debug(int from) override;

  static constexpr double EarthRadius = 6356766.0 / fttom;
  static constexpr double a = 611.2/psftopa; // psf
  static constexpr double b = 17.62; // 1/degC
  static constexpr double c = 243.12; // degC
  static constexpr double Mwater = 18.016 * kgtoslug / 1000.0;
  static constexpr double Rdry = Rstar / Mair;
  static constexpr double Rwater = Rstar / Mwater;
};
 
} // namespace JSBSim
 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
#endif