Published January 29, 2024 | Version v1.0.5
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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 equilence ratio)

This project is also part of the PhD of Alberto Cuadra-Lara.


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