Combustion Chemistry (2D) — Stoichiometry, Flame Temperature & Ignition Limits

Combustion Chemistry

Real fuel + O₂ stoichiometry, adiabatic flame temperature from heat-of-combustion, and real flammability limits. Outside the flammable range the mixture will not ignite.

Fuel

Fuel type Equivalence ratio φ 1.00

φ < 1: lean (excess air) · φ = 1: stoichiometric · φ > 1: rich (excess fuel)

Unignited mixture

Stoichiometry

Balanced equation

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ΔH° (per mol fuel)

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Stoich. O₂ : fuel

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Stoich. air : fuel (mass)

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Flammability range (φ)

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Adiabatic flame T (stoich.)

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How it's modelled

Adiabatic flame temperature is computed from the real ΔH° of combustion divided by the heat capacity of the product gases (CO₂, H₂O, N₂ diluent from air). Ignition follows an Arrhenius-scaled autocatalytic burn: rate ∝ exp(−E_a/RT), E_a ≈ 200 kJ/mol, so ignition stalls near the flammability limits and runs away near stoichiometric.

Fuel: Methane · φ = 1.00

Flame temperature: 300 K

Status: unignited