| Cantera 3.0.0

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Physical Constants
Global Data

Physical constants used by Cantera. More...

Collaboration diagram for Physical Constants:

## Detailed Description

Physical constants used by Cantera.

Cantera uses the MKS system of units. The unit for moles is defined to be the kmol. All values of physical constants are consistent with the 2018 CODATA recommendations.

## Numerical Constants
const double | Pi = 3.14159265358979323846
| Pi.
const double | Sqrt2 = 1.41421356237309504880
| Sqrt(2)

## Defined Constants
These constants are defined by CODATA to have a particular value; see NIST Reference on Constants, Units, and Uncertainty.
const double | Avogadro = 6.02214076e26
| Avogadro's Number \( N_{\mathrm{A}} \) [number/kmol].
const double | Boltzmann = 1.380649e-23
| Boltzmann constant \( k \) [J/K].
const double | Planck = 6.62607015e-34
| Planck constant \( h \) [J-s].
const double | ElectronCharge = 1.602176634e-19
| Elementary charge \( e \) [C].
const double | lightSpeed = 299792458.0
| Speed of Light in a vacuum \( c \) [m/s].
const double | OneAtm = 1.01325e5
| One atmosphere [Pa].
const double | OneBar = 1.0E5
| One bar [Pa].

## Measured Constants
These constants are measured and reported by CODATA
const double | fineStructureConstant = 7.2973525693e-3
| Fine structure constant \( \alpha \) [].
const double | ElectronMass = 9.1093837015e-31
| Electron Mass \( m_e \) [kg].

## Derived Constants
These constants are found from the defined and measured constants
const double | GasConstant = Avogadro * Boltzmann
| Universal Gas Constant \( R_u \) [J/kmol/K].
const double | logGasConstant = std::log(GasConstant)
const double | GasConst_cal_mol_K = GasConstant / 4184.0
| Universal gas constant in cal/mol/K.
const double | StefanBoltz = 2.0 * std::pow(Pi, 5) * std::pow(Boltzmann, 4) / (15.0 * std::pow(Planck, 3) * lightSpeed * lightSpeed)
| Stefan-Boltzmann constant \( \sigma \) [W/m2/K4].
const double | Faraday = ElectronCharge * Avogadro
| Faraday constant \( F \) [C/kmol].
const double | permeability_0 = 2 * fineStructureConstant * Planck / (ElectronCharge * ElectronCharge * lightSpeed)
| Permeability of free space \( \mu_0 \) [N/A2].
const double | epsilon_0 = 1.0 / (lightSpeed * lightSpeed * permeability_0)
| Permittivity of free space \( \varepsilon_0 \) [F/m].

## Variable Documentation

## ◆ Pi

const double Pi = 3.14159265358979323846

Pi.

Definition at line 68 of file ct_defs.h.

## ◆ Sqrt2

const double Sqrt2 = 1.41421356237309504880

Sqrt(2)

Definition at line 71 of file ct_defs.h.

## ◆ Avogadro

const double Avogadro = 6.02214076e26

Avogadro's Number \( N_{\mathrm{A}} \) [number/kmol].

Definition at line 81 of file ct_defs.h.

## ◆ Boltzmann

const double Boltzmann = 1.380649e-23

Boltzmann constant \( k \) [J/K].

Definition at line 84 of file ct_defs.h.

## ◆ Planck

const double Planck = 6.62607015e-34

Planck constant \( h \) [J-s].

Definition at line 87 of file ct_defs.h.

## ◆ ElectronCharge

const double ElectronCharge = 1.602176634e-19

Elementary charge \( e \) [C].

Definition at line 90 of file ct_defs.h.

## ◆ lightSpeed

const double lightSpeed = 299792458.0

Speed of Light in a vacuum \( c \) [m/s].

Definition at line 93 of file ct_defs.h.

## ◆ OneAtm

const double OneAtm = 1.01325e5

One atmosphere [Pa].

Definition at line 96 of file ct_defs.h.

## ◆ OneBar

const double OneBar = 1.0E5

One bar [Pa].

Definition at line 99 of file ct_defs.h.

## ◆ fineStructureConstant

const double fineStructureConstant = 7.2973525693e-3

Fine structure constant \( \alpha \) [].

Definition at line 108 of file ct_defs.h.

## ◆ ElectronMass

const double ElectronMass = 9.1093837015e-31

Electron Mass \( m_e \) [kg].

Definition at line 111 of file ct_defs.h.

## ◆ GasConstant

const double GasConstant = Avogadro * Boltzmann

Universal Gas Constant \( R_u \) [J/kmol/K].

Definition at line 120 of file ct_defs.h.

## ◆ logGasConstant

const double logGasConstant = std::log(GasConstant)

Definition at line 122 of file ct_defs.h.

## ◆ GasConst_cal_mol_K

const double GasConst_cal_mol_K = GasConstant / 4184.0

Universal gas constant in cal/mol/K.

Definition at line 125 of file ct_defs.h.

## ◆ StefanBoltz

const double StefanBoltz = 2.0 * std::pow(Pi, 5) * std::pow(Boltzmann, 4) / (15.0 * std::pow(Planck, 3) * lightSpeed * lightSpeed)

Stefan-Boltzmann constant \( \sigma \) [W/m2/K4].

Definition at line 128 of file ct_defs.h.

## ◆ Faraday

const double Faraday = ElectronCharge * Avogadro

Faraday constant \( F \) [C/kmol].

Definition at line 131 of file ct_defs.h.

## ◆ permeability_0

const double permeability_0 = 2 * fineStructureConstant * Planck / (ElectronCharge * ElectronCharge * lightSpeed)

Permeability of free space \( \mu_0 \) [N/A2].

Definition at line 134 of file ct_defs.h.

## ◆ epsilon_0

const double epsilon_0 = 1.0 / (lightSpeed * lightSpeed * permeability_0)

Permittivity of free space \( \varepsilon_0 \) [F/m].

Definition at line 137 of file ct_defs.h.