physics::us Namespace Reference

Physical constants defined in U.S. Customary units.

Variables
constexpr double	kOrificeAreaFactor = 1300.0
	Orifice area factor for volumetric flow calculations \([\unit{\dimensionless}]\).
constexpr double	kAtmosphericPressurePsi = 14.7
	Standard atmospheric pressure at sea level \([\unit{psia}]\).
constexpr double	kWaterBoilingPointF = 212.0
	Boiling point of water \([\unit{\degreeFahrenheit}]\).
constexpr double	kSpecificHeatWaterVapor = 0.481
	Specific heat of water vapor \([\unit{\btu\per\pound\degreeFahrenheit}]\).
constexpr double	kWaterEvaporation = 970.0
	Latent heat of evaporation for water \([\unit{\btu\per\pound}]\).
constexpr double	kStefanBoltzmann = 1.713441e-9
	Stefan–Boltzmann constant \([\unit{\btu\per\hour\foot\squared\degreeRankine\tothe{4}}]\).
constexpr double	kStandardGasTemperatureR = 520.0
	Standard gas temperature for exhaust calculations \([\unit{\degreeRankine}]\).
constexpr double	kAmbientTemperatureF = 60.0
	Ambient reference temperature for exhaust calculations \([\unit{\degreeFahrenheit}]\).
constexpr double	kSpecificHeatAirBase = 0.017828518
	Base specific heat of air \([\unit{\btu\per\pound\degreeFahrenheit}]\).
constexpr double	kSpecificHeatAirCoeff = 0.000002556
	Temperature coefficient for specific heat of air \([\unit{\btu\per\pound\degreeFahrenheit\per\degreeFahrenheit}]\).
constexpr double	kAirCorrectionBase = -1.078913827
	Base for air correction in exhaust gas heat loss calculations \([\unit{\btu\per\pound}]\).
constexpr double	kWaterDensity = 8.335
	Water density \([\unit{lb/gal}]\).
constexpr double	kAirSensibleHeatFactor = 1.08
	Sensible heat factor for air flow \([\unit{Btu\cdot\minute\per(\cubicFoot\cdot\degreeF\cdot\hour)}]\).
constexpr double	kWaterSensibleHeatFactor = 500.0
	Sensible heat factor for water flow \([\unit{Btu\cdot\minute\per(\gallon\cdot\degreeF\cdot\hour)}]\).

Variable Documentation

kAirCorrectionBase

constexpr double physics::us::kAirCorrectionBase = -1.078913827

inlineconstexpr

Used for exhaust gas heat loss calculations in non-EAF electric furnaces.

Definition at line 111 of file constants.h.

kAirSensibleHeatFactor

constexpr double physics::us::kAirSensibleHeatFactor = 1.08

inlineconstexpr

Product of standard air density (0.075 lb/ft³), specific heat of air (0.24 Btu/lb·°F), and the minutes-to-hours conversion factor (60 min/hr): 0.075 × 0.24 × 60 = 1.08. Used to calculate sensible heat transfer rate of an air stream in U.S. customary units.

Definition at line 126 of file constants.h.

kAmbientTemperatureF

constexpr double physics::us::kAmbientTemperatureF = 60.0

inlineconstexpr

Definition at line 93 of file constants.h.

kAtmosphericPressurePsi

constexpr double physics::us::kAtmosphericPressurePsi = 14.7

inlineconstexpr

Used as the reference pressure for gas property and flow calculations in U.S. customary units.

Note

1 atmosphere = 14.7 psia (pounds per square inch absolute).

Definition at line 60 of file constants.h.

kOrificeAreaFactor

constexpr double physics::us::kOrificeAreaFactor = 1300.0

inlineconstexpr

Empirical, effectively dimensionless factor used in U.S. customary orifice meter equations to convert orifice diameter (in) squared to effective area for volumetric flow (scfh).

Note

Standard value for fuel-fired furnace gas flow calculations.

Definition at line 53 of file constants.h.

kSpecificHeatAirBase

constexpr double physics::us::kSpecificHeatAirBase = 0.017828518

inlineconstexpr

Used for exhaust gas heat loss calculations in non-EAF electric furnaces.

Definition at line 99 of file constants.h.

kSpecificHeatAirCoeff

constexpr double physics::us::kSpecificHeatAirCoeff = 0.000002556

inlineconstexpr

Used for exhaust gas heat loss calculations in non-EAF electric furnaces.

Definition at line 105 of file constants.h.

kSpecificHeatWaterVapor

constexpr double physics::us::kSpecificHeatWaterVapor = 0.481

inlineconstexpr

Definition at line 70 of file constants.h.

kStandardGasTemperatureR

constexpr double physics::us::kStandardGasTemperatureR = 520.0

inlineconstexpr

This is an absolute temperature (520°R = 60°F + 460), commonly used as the reference for gas property calculations in U.S. customary units.

Definition at line 88 of file constants.h.

kStefanBoltzmann

constexpr double physics::us::kStefanBoltzmann = 1.713441e-9

inlineconstexpr

Source: [2]

Definition at line 81 of file constants.h.

kWaterBoilingPointF

constexpr double physics::us::kWaterBoilingPointF = 212.0

inlineconstexpr

Definition at line 65 of file constants.h.

kWaterDensity

constexpr double physics::us::kWaterDensity = 8.335

constexpr

Used for water flow calculations in process heating systems. Source: CRC Handbook of Chemistry and Physics.

Definition at line 118 of file constants.h.

kWaterEvaporation

constexpr double physics::us::kWaterEvaporation = 970.0

inlineconstexpr

Definition at line 75 of file constants.h.

kWaterSensibleHeatFactor

constexpr double physics::us::kWaterSensibleHeatFactor = 500.0

inlineconstexpr

Product of standard water density (8.33 lb/gal), specific heat of water (1.0 Btu/lb·°F), and the minutes-to-hours conversion factor (60 min/hr): 8.33 × 1.0 × 60 ≈ 500. Used to calculate sensible heat transfer rate of a water stream in U.S. customary units.

Definition at line 134 of file constants.h.