Adiabatic Flame Temperature Calculator

Adiabatic Flame Temperature Calculator: The Theoretical Ceiling of Combustion Heat

The adiabatic flame temperature is the highest temperature combustion products could theoretically reach if all the chemical energy released by burning fuel went directly into heating the products, with zero heat loss to the surroundings. It's a benchmark used to judge how close real combustion systems come to ideal performance, and to size equipment that must survive peak thermal conditions.

The Formula

T_ad = T_initial + (Heating Value × (1 − Heat Loss%)) / ((1 + AFR) × Cp_products)

Worked Example

Air and fuel enter at 298 K, the fuel's heating value is 50,000 kJ/kg, the air-fuel ratio is 17.2, and the specific heat of the combustion products is 1.15 kJ/kg·K.

T_ad = 298 + 50,000 / (18.2 × 1.15) = 2,686.9 K

How to Use This Calculator

1. Enter the initial temperature of the incoming air and fuel.
2. Enter the fuel's heating value in kJ/kg.
3. Enter the air-fuel ratio (by mass).
4. Enter the specific heat of the combustion products in kJ/kg·K.
5. Optionally enter a heat loss percentage to model non-ideal conditions.
6. Click Calculate to see the adiabatic flame temperature.

Related Calculations

Compare against the Flame Temperature Calculator, which accounts for excess-air cooling of the real, non-adiabatic flame.