Initialization module#

CT built-in functions are written to perform fast parametric studies, thus the data passed between the functions has been organized in a hierarchical tree structure (except for the GUI which is based on OOP) as shown in Fig.1, namely:

  • self (App): parent node; contains all the data of the code, e.g., databases, input values, results.

  • Constants (C): contains constant values.

  • Elements (E): contains data of the chemical elements in the problem (names and index for fast data access).

  • Species (S): contains data of the chemical species in the problem (names and index for fast data access), as well as lists (cells) with the species for a complete combustion.

  • Problem Description (PD): contains data of the problem to solve, e.g., initial mixture (composition, temperature, pressure), problem type and its configuration.

  • Problem Solution (PS): contains results (mixtures).

  • Tuning Properties (TN): contains parameters to control the numerical error of the numerical methods implemented in the different modules.

  • Miscellaneous (Misc): contains values to configure the auto-generated plots and export setup, as well as flags, e.g., setting FLAG_RESULTS = true (by default) the results are shown in the command window (only in the desktop environment).


Figure 1: Combustion Toolbox hierarchical data tree structure, where App.m is the initialization function.

App#

Routines to initialize the Combustion Toolbox.

Routines
App(varargin)#

Generate self variable with all the data required to initialize the computations

Optional Args:

  • LS (cell): List of species

  • obj (class): Class combustion_toolbox_app (GUI)

  • type (str): If value is fast initialize from the given Databases

  • DB_master (struct): Master database

  • DB (struct): Database with custom thermodynamic polynomials functions generated from NASAs 9 polynomials fits

Returns:

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

contained_elements(self)#

Obtain containted elements from the given set of species (reactants and products)

Parameters:

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

Returns:

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

initialize(self)#
This routine has three tasks:

  • Check that all species are contained in the Database

  • Establish cataloged list of species according to the state of the phase (gaseous or condensed). It also obtains the indices of cryogenic liquid species, e.g., liquified gases

  • Compute Stoichiometric Matrix

Parameters:

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

Returns:

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

set_DB(self, FLAG_REDUCED_DB, FLAG_FAST)#

Generate Database with custom polynomials from DB_master

Parameters:

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

  • FLAG_REDUCED_DB (bool) – Flag compute from reduced database

  • FLAG_FAST (bool) – Flag load databases

Returns:

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

Constants#

Routines to initialize the Constants branch in the self variable (struct).

Routines
Constants()#

Initialize struct with constants data

Returns:

self (struct) – struct with constants data

Elements#

Routines to initialize the Elements branch in the self variable (struct).

Routines
Elements()#

Initialize struct with elements data

Returns:

self (struct) – struct with elements data

set_elements()#

Set cell with elements name

Returns:

Tuple containing –

  • elements (cell): Elements

  • NE (struct): Number of elements

Miscellaneous#

Routines to initialize the Miscellaneous branch in the self variable (struct).

Routines
Miscellaneous()#

Initialize struct with miscellaneous data

Returns:

self (struct) – struct with miscellaneous data

ProblemDescription#

Routines to initialize the ProblemDescription branch in the self variable (struct).

Routines
ProblemDescription()#

Initialize struct with problem description data

Returns:

self (struct) – struct with problem description data

ProblemSolution#

Routines to initialize the ProblemSolution branch in the self variable (struct).

Routines
ProblemSolution()#

Initialize struct with problem solution data

Returns:

self (struct) – struct with problem solution data

Species#

Routines to initialize the Species branch in the self variable (struct).

Routines
Species()#

Initialize struct with problem solution data

Returns:

self (struct) – struct with problem solution data

get_index_ions(species)#

Get index of ions for the given list of species

Parameters:

species (str) – List of species

Returns:

index (float) – Index of ions

list_species(varargin)#

Set list of species in the mixture (reactants and products)

Predefined list of species:

  • SOOT FORMATION (default)

  • COMPLETE

  • HC/O2/N2 EXTENDED

  • SOOT FORMATION EXTENDED

  • NASA ALL

  • NASA ALL CONDENSED

  • NASA ALL IONS

  • AIR, DISSOCIATED AIR

  • AIR IONS, AIR_IONS

  • IDEAL_AIR, AIR_IDEAL

  • HYDROGEN

  • HYDROGEN_L, HYDROGEN (L)

  • HC/O2/N2 PROPELLANTS

  • SI/HC/O2/N2 PROPELLANTS

Parameters:

empty (none) – return default list of species (soot formation)

Optional Args:

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

  • LS (cell): Name list species / list of species

  • EquivalenceRatio (float): Equivalence ratio

  • EquivalenceRatio_soot (float): Equivalence ratio in which theoretically appears soot

Returns:

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

TuningProperties#

Routines to initialize the TuningProperties branch in the self variable (struct).

Routines
TuningProperties()#

Initialize struct with tunning properties attributes

FLAG_FAST#

Flag indicating use guess composition of the previous computation (default: false)

Type:

bool

itMax_gibbs#

Max number of iterations - Gibbs/Helmholtz minimization method (default: 70)

Type:

float

itMax_ions#

Max number of iterations - charge balance (ions) (default: 30)

Type:

float

tolN#

Tolerance of the Gibbs/Helmholtz minimization method (default: 1e-14)

Type:

float

tolE#

Tolerance of the mass balance (default: 1e-06)

Type:

float

tol_pi_e#

Tolerance of the dimensionless Lagrangian multiplier - ions (default: 1e-04)

Type:

float

tol0#

Tolerance of the root finding algorithm (default: 1e-03)

Type:

float

root_method#

Method for root finding (default: newton)

Type:

function

itMax#

Max number of iterations - root finding method - HP, EV, SP, SV (default: 30)

Type:

float

root_T0_l#

First guess T [K] left branch - root finding method (default: 1000)

Type:

float

root_T0_r#

First guess T [K] right branch - root finding method (default: 3000)

Type:

float

root_T0#

Guess T[K] if it’s of previous range - root finding method (default: 3000)

Type:

float

tol_shocks#

Tolerance of shocks routines (default: 5e-05)

Type:

float

it_shocks#

Max number of iterations - shocks and detonations (default: 50)

Type:

float

Mach_thermo#

Preshock Mach number above which T2_guess will be computed considering h2 = h1 + u1^2 / 2 (default: 2)

Type:

float

tol_oblique#

Tolerance oblique shocks (default: 1e-03)

Type:

float

it_oblique#

Max number of iterations - oblique shocks (default: 20)

Type:

float

N_points_polar#

Number of points to compute shock polar (default: 100)

Type:

float

it_guess_det#
Type:

float

tol_rocket#

Tolerance rocket performance (default: 1e-04)

Type:

float

it_rocket#

Max number of iterations - rocket performance (default: 10)

Type:

float

Returns:

self (struct) – struct with tunning properties data