Combustion Toolbox: A MATLAB-GUI based open-source tool for solving gaseous combustion problems

Main features

• The code stems from the minimization of the free energy of the system by using Lagrange multipliers combined with a Newton-Raphson method, upon condition that initial gas properties are defined by two functions of states (e.g., temperature and pressure)
• When temperature is not externally imposed, the code retrieves a routine also based on Newton-Raphson method to find the equilibrium temperature
• Solve processes that involve strong changes in the dynamic pressure, such as detonations and shock waves in the steady state
• Find the equilibrium conditions of the different phenomena undergoing behind the shock: molecular vibrational excitation up to dissociation, and electronic excitation up to ionization, thereby providing the properties of the gas in plasma state within the temperature range given by the NASA’s 9-coefficient polynomial fits.
• Calculate the chemical equilibrium composition of a mixture by selecting which species can react or remain chemically frozen (inert).
• The corresponding thermodynamic properties of the species are modelled with NASA’s 9-coefficient polynomial fits, which ranges up to 20000 K, and the ideal gas equation of state
• Results are in excellent agreement with NASA’s Chemical Equilibrium with Applications (CEA) program, CANTERA and Caltech’s Shock and Detonation Toolbox, and TEA
  • Chemical equilibrium problems
• TP: Equilibrium composition at defined temperature and pressure
• HP: Adiabatic temperature and composition at constant pressure
• SP: Isentropic compression/expansion to a specified pressure
• TV: Equilibrium composition at defined temperature and constant volume
• EV: Adiabatic temperature and composition at constant volume
• SV: Isentropic compression/expansion to a specified volume
  • Shock calculations:
• Pre-shock and post-shock states
• Equilibrium or frozen composition
• Incident or reflected shocks
• Chapman-Jouguet detonations, overdriven detonations, and underdriven detonations
• Reflected detonations
• Oblique shocks/detonations
• Shock/detonation polar curves for incident and reflected states
• Hugoniot curves
• Ideal jump conditions for a given adiabatic index and pre-shock Mach number
  • Rocket propellant performance assuming:
• Infinite-Area-Chamber model (IAC)
• Finite-Area-Chamber model (FAC)
  • All the routines and computations are encapsulated in a more comprehensive and user-friendly GUI
  • The code is in it’s transition to Python
  • Export results in a spreadsheet
  • Export results as a .mat format
  • Display predefined plots (e.g., molar fraction vs. equivalence ratio)

Start here!

• The tutorials will help you get started using the Combustion Toolbox on your pc.
• See examples of Combustion Toolbox applications.
• Check the documentation of almost every functions.

Gallery

We have several examples of what the Combustion Toolbox can do. Here we show a preview of the GUI and some results obtained from the Combustion Toolbox.

Figure 1: Current state of the GUI.

Figure 2: Hugoniot curves for different molecular gases at pre-shock temperature T1 = 300 K and pressure p1 = 1 atm [numerical results obtained with Combustion Toolbox (lines) and contrasted with NASA’s Chemical Equilibrium with Applications (CEA) code excluding ionization (symbols)].

Figure 3: Example CJ detonation for lean to rich CH4-air mixtures at standard conditions: (a) variation of molar fraction, (b) variation of temperature. The computational time was of 9.25 seconds using a Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz for a set of 24 species considered and a total of 351 case studies.

Figure 4: Pressure-deflection shock polar (left) and wave angle-deflection shock polar (right) for an air mixture (78.084% N2, 20.9476% O2, 0.9365% Ar, 0.0319% CO2) at pre-shock temperature T1 = 300 K and pressure p1 = 1 atm, and a range of preshock Mach numbers M1 = [2, 14]; line: considering dissociation, ionization, and recombination in multi-species mixtures; dashed: considering a thermochemically frozen air mixture.

Contributing

Please read CONTRIBUTING.md for details of the process for submitting pull requests to the repository.

Please send feedback or inquiries to acuadra@ing.uc3m.es

Thank you for using the Combustion Toolbox!

Acknowledgements

• 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.
• Combustion Toolbox's periodic table layout is based in the following repository: Bruno Salcedo (2018). latex-periodic-table (https://github.com/brunosalcedo/latex-periodic-table), Github. Retrieved October 15, 2022.

People

• Alberto Cuadra-Lara - Lead developer
• César Huete - Advisor
• Marcos Vera - Advisor

Grupo de Mecánica de Fluidos, Universidad Carlos III, Av. Universidad 30, 28911, Leganés, Spain

See also the list of contributors who participated in this project.

Citing Combustion Toolbox

@article{cuadra2024a_preprint,
    title         = {{Combustion Toolbox: An open-source thermochemical code for gas- and condensed-phase problems involving chemical equilibrium}},
    author        = {Cuadra, A. and Huete, C. and Vera, M.},
    journal       = {{arXiv preprint arXiv:2409.15086}},
    year          = {2024},
    eprint        = {2409.15086},
    archivePrefix = {arXiv},
    primaryClass  = {physics.chem-ph},
    doi           = {10.48550/arXiv.2409.15086}
}

@misc{combustiontoolbox,
    author  = "Cuadra, A. and Huete, C. and Vera, M.",
    title   = "{Combustion Toolbox: A MATLAB-GUI based open-source tool for solving gaseous combustion problems}",
    year    = 2024,
    note    = "Version 1.1.0",
    doi     = {https://doi.org/10.5281/zenodo.5554911}
}