/// Converts from PSF (pounds per square foot) to one of several unit systems.
protected double ConvertFromPSF(double p, ePressure unit = ePressure.ePSF)
{
double targetPressure = 0; // Pressure
switch (unit)
{
case ePressure.ePSF:
targetPressure = p;
break;
case ePressure.eMillibars:
targetPressure = p / 2.08854342;
break;
case ePressure.ePascals:
targetPressure = p / 0.0208854342;
break;
case ePressure.eInchesHg:
targetPressure = p / 70.7180803;
break;
default:
throw new Exception("Undefined pressure unit given");
}
return(targetPressure);
}
/** Sets the partial pressure of water vapor.
* @param Pv The vapor pressure in the units specified
* @param unit The unit of measure that the specified vapor pressure is
* supplied in. */
public void SetVaporPressure(ePressure unit, double Pa)
{
double altitude = CalculatePressureAltitude(Pressure, 0.0);
double VaporPressure = ConvertToPSF(Pa, unit);
VaporMassFraction = Rdry * VaporPressure / (Rwater * (Pressure - VaporPressure));
ValidateVaporMassFraction(altitude);
}
/** Returns the saturated pressure of water vapor.
* @param to The unit of measure that the water vapor should be supplied in.
*/
public double GetSaturatedVaporPressure(ePressure to)
{
return(ConvertFromPSF(saturatedVaporPressure, to));
}
/** Returns the partial pressure of water vapor.
* @param to The unit of measure that the water vapor should be supplied in.
*/
public double GetVaporPressure(ePressure to)
{
double VaporPressure = Pressure * VaporMassFraction / (VaporMassFraction + Rdry / Rwater);
return(ConvertFromPSF(VaporPressure, to));
}
/** Sets the sea level pressure for modeling an off-standard pressure
* profile. This could be useful in the case where the pressure at an
* airfield is known or set for a particular simulation run.
* @param pressure The pressure in the units specified.
* @param unit the unit of measure that the specified pressure is
* supplied in.*/
public override void SetPressureSL(ePressure unit, double pressure)
{
SLpressure = ConvertToPSF(pressure, unit);
CalculateSLDensity();
CalculatePressureBreakpoints(SLpressure);
}
/// <summary>
/// Sets the sea level pressure for modeling.
/// </summary>
/// <param name="unit">the unit of measure that the specified pressure is supplied in.</param>
/// <param name="pressure">The pressure in the units specified.</param>
public virtual void SetPressureSL(ePressure unit, double pressure)
{
double press = ConvertToPSF(pressure, unit);
SLpressure = press;
}
/// <summary>
/// Returns the sea level pressure in target units, default in psf.
/// </summary>
/// <param name="to"></param>
/// <returns></returns>
public virtual double GetPressureSL(ePressure to = ePressure.ePSF)
{
return(ConvertFromPSF(SLpressure, to));
}
