Common classes

Here we can find the documentation for the common functions and classes implemented in the Combustion Toolbox (CT).

Constants

class Constants

Bases: handle

Class with constants data

R0

Universal gas constant [J/(K mol)]

Type:

float

G

Standard gravity [m/s2]

Type:

float

NA

Avogadro’s number [molecule/mol]

Type:

float

release

Release of the Combustion Toolbox

Type:

char

date

Date of the release

Type:

char

Examples

• R0 = Constants.R0

• g = Constants.G

• release = Constants.release

G = '9.80665'

Standard gravity [m/s2]

HBAR = '6.626070041e-34'

Planck constant [J-s]

KB = '1.38064852e-23'

Boltzmann constant [J/K]

NA = '6.0221415e23'

Avogadro’s number [molecule/mol]

R0 = '8.31446261815324'

Universal gas constant [J/(K mol)]

date = "'20 Mar 2025'"

Release date

release = "'v1.2.1'"

Release version

Units

class Units

Bases: handle

Class with conversion factors between different units

C2K = '@(x) x + 273.15'

Degrees Celsius to Kelvin

F2C = '@(x) (x - 32) * 5/9'

Fahrenheit to degrees Celsius

K2C = '@(x) x - 273.15'

Temperature conversion factors

K2F = '@(x) (x - 273.15) * 9/5 + 32'

Kelvin to Fahrenheit

L2ft3 = '28.3168^-1'

Liters to cubic feet

L2m3 = '1e-3'

Liters to cubic meters

Pa2atm = '101325^-1'

Pascales to atmospheres

Pa2bar = '1e-5'

Pascals to bar

atm2Pa = '101325'

Atmospheres to Pascales

atm2bar = '1.01325'

Pressure conversion factors

bar2Pa = '1e5'

Bar to Pascals

bar2atm = '1.01325^-1'

Bar to atmospheres

static convert(value_in, unit_in, unit_out)

Convert a value from one unit to another

Parameters:

• value_in (double) – Value to convert

• unit_in (char) – Unit of the input value

• unit_out (char) – Unit of the output value

Returns:

value_out – Value converted to the output unit

Examples

• Units.convert(1, ‘atm’, ‘bar’)

• Units.convert(273.15, ‘K’, ‘C’)

• Units.convert(1, ‘kg’, ‘lbs’)

• Units.convert(1, ‘m3’, ‘ft3’)

• Units.convert(1, ‘m3’, ‘L’)

static convertData2VelocityField(data)

Convert the input to a VelocityField object

Parameters:

data – Either a VelocityField object, a struct, or a 4D matrix

Returns:

velocity (VelocityField) – VelocityField object

static convertWeightPercentage2moles(listSpecies, weightPercentage, database)

Convert weight percentage (wt%) to moles

Parameters:

• listSpecies (cell) – List of species

• weightPercentage (float) – Weight percentage of the species [%]

• database (Database) – Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

moles (float) – Number of moles [mol]

Example

moles = Units.WeightPercentage2moles({‘H2O’, ‘CO2’}, [50, 50], database)

ft32L = '28.3168'

Cubic feet to liters

ft32m3 = '35.3147^-1'

Cubic feet to cubic meters

g2kg = '1e-3'

Grams to kilograms

kg2g = '1e3'

Kilograms to grams

kg2lbs = '2.20462'

Mass conversion factors

lbs2kg = '0.453592'

Pounds to kilograms

m32L = '1e3'

Cubic meters to liters

m32ft3 = '35.3147'

Volume conversion factors