constants.hpp

#pragma once
 
#include <cmath>
 
namespace constants
{
    static const double pi = 4.0*std::atan(1.0);
 
    static const double kelvin = 273.15;
 
    static const double standardAtmosphere = 101325;
 
    static const double kelvinToRankine = 9.0/5.0;
 
    static const double standardTemperature = kelvin + 15;
 
    static const double standardPressure = 101325;
 
    static const double gasConstant = 8.3144598;            // [J/mol K] == [m3 Pa /mol K]
 
    static const double gasConstantBTU = 1.98588;
 
    static const double pascalToPoundForcePerSquareFoot = 0.3048*0.3048/4.4482216152605; // 4.448.. is lbf to Newton, 0.3048 is foot to meter
 
    static const double footPoundForce = 1.355817948; // joule
    static const double slug = 14.5939; // kg
    static const double rankine = 5.0/9.0; // Kelvin
    static const double footPoundForcePerSlugRankine = footPoundForce/(slug*rankine); // J/(kg K)
 
    static const double molarMassOfAir = 28.967; // [g/mol] reference for calculating specific gravity
}