Mach Number Calculator (Combustion Gas)

Mach Number Calculator: Check Compressibility of Combustion Gas Flow

At high velocities, particularly in burner nozzles and constricted passages, gas flow can approach or exceed the local speed of sound, where compressibility effects become significant and simple incompressible flow assumptions break down. This calculator computes the Mach number to flag when that matters.

The Formula

a = √(γ × R × T), then M = V / a

Worked Example

Gas moves at 340 m/s at 288 K, with a specific heat ratio of 1.4 and specific gas constant of 287 J/kg·K (typical for air).

a = √(1.4 × 287 × 288) = 340.17 m/s, so M = 340 / 340.17 = 0.9995

How to Use This Calculator

1. Enter the gas velocity in m/s.
2. Optionally adjust the specific heat ratio (gamma, 1.4 for air and most combustion gases by default).
3. Optionally adjust the specific gas constant (287 J/kg·K for air by default).
4. Enter the gas temperature in Kelvin.
5. Click Calculate to get the Mach number.

Related Calculations

Use with the Burner Pressure Drop Calculator when designing high-velocity burner nozzles.