Utilities#

A collection of routines with multiple purposes organized as follows:

unclasified
databases
display
eos
export
extensions
root_finding
thermo
validations

Unclasified utility functions#

A collection of unclasified functions necessary to perform all the calculations in CT.

Routines

Compute_YFuel(mix, mix_Fuel)#

Compute fuel mass fraction [-]

Parameters:

mix (struct) – Properties of the mixture (fuel + oxidizer + inerts)
mix_Fuel (struct) – Properties of the mixture (fuel)

Returns:

Yi_Fuel (float) – Mass fractions of the fuel mixture

Example

Yi_Fuel = Compute_YFuel(mix, mix_Fuel)

GPL()#

Return Combustion Toolbox license

Returns:: license_content (char) – The license text

Example

license_content = GPL()

append_cells(cell1, cell2, varargin)#

Append two or more cells in one common cell

Parameters:

cell1 (struct) – Cell 1
cell2 (struct) – Cell 2

Optional Args:: celli (struct): Additional cells

Returns:: append_cell (struct) – Merged cell

append_structs(s1, s2, varargin)#

Append two or more structs in one common struct

Parameters:

s1 (struct) – Struct 1
s2 (struct) – Struct 2

Optional Args:: si (struct): Additional structs

Returns:: append_s (struct) – Merged struct

assign_vector2cell(cell, vector, varargin)#

Assign values of a vector into a cell

Parameters:

cell (cell) – Cell in which the values of the given vector are going to be included
vector (any) – Vector with the values that are going to be included in the cell

Optional Args:: ind (float): List of index positions to assign specific positions to the cell

Returns:: cell (cell) – Cell with the values of the given vector

cell2vector(value, varargin)#

Convert values of an individual cell into a vector. If the value correspond with a struct it can return as a vector the values of a given fieldname.

Parameters:: value (cell or struct) – Data of the mixture, conditions, and databases

Optional Args:: field (char): Fieldname of the given value (only for struct or objects)

Returns:: vector (any) – Vector with the values of the individual cell/fieldname (only for struct or objects)

convert_Pa_to_bar(value)#

Convert pressure in [Pa] units to [bar]

Parameters:: value (float) – Pressure value(s) in [bar]
Returns:: value (float) – Pressure value(s) in [bar]

Example

value = convert_Pa_to_bar(1e5)

convert_atm_to_bar(value)#

Convert pressure in [atm] units to [bar]

Parameters:: value (float) – Pressure value(s) in [atm]
Returns:: value (float) – Pressure value(s) in [bar]

Example

value = convert_atm_to_bar(1)

convert_bar_to_Pa(value)#

Convert pressure in [bar] units to [Pa]

Parameters:: value (float) – Pressure value(s) in [bar]
Returns:: value (float) – Pressure value(s) in [Pa]

Example

value = convert_bar_to_Pa(1)

convert_bar_to_atm(value)#

Convert pressure in [bar] units to [atm]

Parameters:: value (float) – Pressure value(s) in [bar]
Returns:: value (float) – Pressure value(s) in [atm]

Example

value = convert_bar_to_atm(1.01325)

getTypeSpecies(obj)#

Create cell array with the type of species in the mixture

Parameters:: obj (Mixture) – Mixture class
Returns:: typeSpecies (cell) – Cell array with the type of species in the mixture

get_FLAG_N(self)#

Flag if the number of moles of fuel, oxidant and inert species is specified. If not, consider 1 mole for the fuel and calculate the remaining moles from the equivalence relation.

Parameters:: self (struct) – Data of the mixture, conditions, and databases
Returns:: self (struct) – Data of the mixture, conditions, and databases

post_results(self)#

Postprocess all the results with predefined plots

Parameters:: self (struct) – Data of the mixture, conditions, and databases

print_error(ME, varargin)#

Print message error

Parameters:: ME (object) – MException object that allows to identify the error

Optional Name-Value Pairs Args:

type (char): Type of message (error, warning, or other)
message_solution (char): Message solution

Returns:: error_message (char) – Message error

Examples

error_message = print_error(ME, ‘Type’, ‘Warning’)
error_message = print_error(ME, ‘Type’, ‘Warning’, ‘Solution’, ‘Returning an empty index value.’)

set_prop(self, varargin)#

Assign property values to the respective variables

Parameters:: self (struct) – Data of the mixture, conditions, and databases

Optional Args:

field (str): Fieldname in Problem Description (PD)
value (float): Value/s to assing in the field in Problem Description (PD)

Returns:: self (struct) – Data of the mixture, conditions, and databases

set_transformation(self, field, value)#

Set the corresponding value of the field in Problem Description (PD)

Parameters:

self (struct) – Data of the mixture, conditions, and databases
field (str) – Fieldname in Problem Description (PD)
value (float) – Value/s to assign to the field

Returns:

self (struct) – Data of the mixture, conditions, and databases

smooth_data(x, y, varargin)#

Smooth data using Fourier NonlinearLeastSquares method

Parameters:

x (float) – data in the x direction
y (float) – data in the y direction

Optional Args:: start_point (float): initial point of the fit

Returns:

Tuple containing

x (float): smooth data in the x direction
y (float): smooth data in the y direction

soundspeed_eq(self, mix, P0, T0)#

Compute speed of sound at equilibrium

Parameters:

self (struct) – Data of the mixture, conditions, and databases
mix (struct) – Struct mix with all the properties of the mixture
P0 (float) – Pressure [bar]
T0 (float) – Temperature [K]

Returns:

sound (float) – sound speed [m/s]

vector2cell(value)#

Create cell array from vector

Parameters:: value (any) – Vector with data of any type
Returns:: c (cell) – Cell with the values of the vector

Database functions#

A collection of functions necessary to obtain generate the databases in CT.

Display functions#

A collection of functions necessary to display the results (command window and plots).

Equation of State functions#

A collection of Equation of States (EoS) implemented in CT.

Export functions#

A collection of functions to export results.

Extensions functions#

A collection of external functions from other repositories.

Combustion Toolbox’s color palette is obtained from the following repository: Stephen (2021). ColorBrewer: Attractive and Distinctive Colormaps (https://github.com/DrosteEffect/BrewerMap), GitHub. Retrieved December 3, 2021.
For validations, Combustion Toolbox uses CPU Info from the following repository: Ben Tordoff (2022). CPU Info (https://github.com/BJTor/CPUInfo/releases/tag/v1.3), GitHub. Retrieved March 22, 2022.
Combustion Toolbox’s splash screen is based on a routine from the following repository: Ben Tordoff (2022). SplashScreen (https://www.mathworks.com/matlabcentral/fileexchange/30508-splashscreen), MATLAB Central File Exchange. Retrieved October 15, 2022.

Root finding algorithms#

Roots algorithm used to obtain the temperature at equilibrium for a given thermochemical transformation. The methods implemented are:

Newton-Raphson method.
Steffensen-Aitken method.

Thermodynamic properties#

Functions to obtain thermodynamic properties from a given mixture.

Routines

MolecularWeight(mix)#

Get the molecular weight [g/mol] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Molecular weight [g/mol] of the mixture

adiabaticIndex(mix)#

Get the adiabatic index [-] of the mixture from the ratio of the specific heat capacities

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Adiabatic index of the mixture [-]

adiabaticIndex_sound(mix)#

Get the adiabatic index [-] of the mixture from definition of sound velocity

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Adiabatic index [-] of the mixture

compressibility_factor(mix)#

Compute compressibility factor of the mixture [-]

Parameters:: mix (struct) – Properties of the mixture
Returns:: Z (float) – Compressibility factor [-]

compute_heatrelease(mix1, mix2)#

Compute heat release [J/kg] of the chemical transformation of the mixture 1 to mixture 2

Parameters:

mix1 (struct) – Properties of the initial mixture
mix2 (struct) – Properties of the final mixture

Returns:

q (float) – heat release [J/kg] == [m^2/s^2] Q (float): dimensionless heat release

compute_sound(T, p, species, composition, varargin)#

Routine to compute sound velocity [m/s] for a given temperature-pressure profile

Parameters:

T (float) – Temperature [K]
p (float) – Pressure [bar]
species (cell) – List of species
composition (float) – composition of species (mol)

Optional Name-Value Pairs Args:: self (struct): Data of the mixtures, conditions, databases

Returns:: sound (float) – Sound velocity [m/s]

Examples

sound = compute_sound(300, 1, {‘H2’, ‘O2’}, [1, 1]) sound = compute_sound(300, 1, {‘H2’, ‘O2’}, [1, 1], ‘self’, self)

cp_mass(mix)#

Get the mass-basis specific heat at constant pressure [kJ/kg-K] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific heat at constant pressure [kJ/kg-K] of the mixture

cp_mole(mix)#

Get the mole-basis specific heat at constant pressure [kJ/mol-K] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific heat at constant pressure [kJ/mol-K] of the mixture

cv_mass(mix)#

Get the mass-basis specific heat at constant volume [kJ/kg-K] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific heat at constant volume [kJ/kg-K] of the mixture

cv_mole(mix)#

Get the mole-basis specific heat at constant volume [kJ/mol-K] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific heat at constant volume [kJ/mol-K] of the mixture

density(mix)#

Get the density [kg/m3] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – density [kg/m3] of the mixture

enthalpy_formation_mass(mix)#

Get the mass specific enthalpy formation [kJ/kg] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific enthalpy formation [kJ/kg] of the mixture

enthalpy_formation_mole(mix)#

Get the mole specific enthalpy formation [kJ/mol] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific enthalpy formation [kJ/mol] of the mixture

enthalpy_mass(mix)#

Get the mass specific enthalpy [kJ/kg] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific enthalpy [kJ/kg] of the mixture

enthalpy_mole(mix)#

Get the mole specific enthalpy [kJ/mol] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific enthalpy [kJ/mol] of the mixture

entropy_mass(mix)#

Get the mass specific entropy [kJ/kg-K] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific entropy [kJ/kg-K] of the mixture

entropy_mole(mix)#

Get the mole specific entropy [kJ/mol-K] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific entropy [kJ/mol-K] of the mixture

equivalenceRatio(mix)#

Get the equivalence ratio of the initial mixture [-]

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Equivalence ratio of the initial mixture [-]

gibbs_mass(mix)#

Get the mass specific gibbs free energy [kJ/kg] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific gibbs free energy [kJ/kg] of the mixture

gibbs_mole(mix)#

Get the mole specific gibbs free energy [kJ/mol] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific gibbs free energy [kJ/mol] of the mixture

humiditySpecific(T, p, humidityRelative)#

Get the specific humidity of air [kg_w/kg_da] at a given temperature, pressure, and relative humidity

Parameters:

T (float) – Temperature [K]
p (float) – Pressure [bar]
humidityRelative (float) – Relative humidity [%]

Returns:

value (float) – Specific humidity of air [kg_w/kg_da]

intEnergy_mass(mix)#

Get the mass specific internal energy [kJ/kg] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass-basis specific internal energy [kJ/kg] of the mixture

intEnergy_mole(mix)#

Get the mole specific internal energy [kJ/mol] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole-basis specific internal energy [kJ/mol] of the mixture

mass(mix)#

Get the mass [kg] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – mass [kg] of the mixture

massFractions(mix)#

Get the mass fractions of all the species in the mixture [-]

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mass fractions of all the species in the mixture [-]

meanMolecularWeight(mix)#

Get the mean molecular weight [g/mol] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mean molecular weight [g/mol] of the mixture

moleFractions(mix)#

Get the mole fractions of all the species in the mixture [-]

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Mole fractions of all the species in the mixture [-]

moles(mix)#

Get the moles [mol] of all the species in the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Moles [mol] of all the species in the mixture

molesGas(mix)#: Get the moles of the gases in the mixture [mol]

pressure(mix)#

Get the pressure [bar] in the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Pressure [bar] in the mixture

soundspeed(mix)#

Get the speed of sound [m/s] in the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Speed of sound [m/s] in the mixture

temperature(mix)#

Get the temperature [K] in the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Temperature [K] in the mixture

velocity_relative(mix)#

Get the velocity of the gases relative to the shock front [m/s] in the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – Velocity of the gases relative to the shock front [m/s] in the mixture

volume(mix)#

Get the volume [m3] of the mixture

Parameters:: mix (struct) – Properties of the mixture
Returns:: value (float) – volume [m3] of the mixture

Validations functions#

A collection of functions to generate the validations automatically.