Flame Speed Calculator

Flame Speed Calculator: Scale Laminar Burning Velocity to Your Conditions

Laminar flame speed is the rate at which a flame front propagates into an unburned fuel-air mixture, and it depends strongly on the mixture's temperature and pressure. This calculator uses the widely applied power-law correlation to scale a known reference flame speed to different operating conditions.

The Formula

S_u = S_u0 × (T_u/T₀)ⁿ × (P/P₀)^m

Worked Example

A reference laminar flame speed of 40 cm/s at 300 K is scaled to an unburned gas temperature of 400 K at the same pressure, using a temperature exponent of 2.

S_u = 40 × (400/300)² × 1 = 71.11 cm/s

How to Use This Calculator

1. Enter the base laminar flame speed for your fuel-air mixture at reference conditions.
2. Enter the actual unburned gas temperature.
3. Optionally adjust the reference temperature, pressure ratio, and exponents (defaults suit many hydrocarbon-air mixtures).
4. Click Calculate to get the scaled flame speed.

Related Calculations

Use the result with the Flame Stability Calculator to check burner flashback and blow-off margins.