Skip to content

Exercise 600.1 — Adiabatic flame temperature

Hydrogen vs kerosene combustion

🧪 Script
equilibrium_calculation.py

Supporting files (same folder):


Learning objectives

  • Compute adiabatic flame temperatures for H₂–air and kerosene–air mixtures
  • Compare equilibrium chemistry with a simplified main-products model
  • Understand how fuel chemistry affects temperature, dissociation, and heat release

Model description

The script computes adiabatic flame temperatures using two approaches:

  1. Full equilibrium calculation

    • Chemical equilibrium at fixed pressure and enthalpy
    • Includes dissociation at high temperature
  2. Main products only

    • Assumes complete combustion to CO₂/H₂O/N₂
    • Neglects dissociation effects

Both are applied to:

  • hydrogen–air mixtures
  • kerosene–air mixtures

How to run

From the script folder (chapters/600_hydrogen_combustion/scripts):

python equilibrium_calculation.py

Guided questions

1) Fuel chemistry and flame temperature

  • Why does hydrogen typically exhibit higher adiabatic flame temperatures?
  • How does molecular structure influence heat release per unit mass?

2) Role of dissociation

  • How large is the difference between equilibrium and main-products results?
  • Why does dissociation limit peak flame temperature?

3) Equivalence ratio effects

  • How does flame temperature vary with equivalence ratio?
  • Are trends similar for hydrogen and kerosene?

Student tasks

Task 1 — Temperature comparison

Compute and report:

  • adiabatic flame temperature for H₂ and kerosene
  • results from both equilibrium and simplified models

Explain the differences physically.


Task 2 — specific heat comparison

Compare specific heats of H₂ and kerosene products at different equivalence ratios.


Limitations

  • No flame structure or kinetics
  • No pressure losses
  • Idealized thermodynamic equilibrium

Results should be interpreted as upper bounds on achievable temperatures.