The critical Mach number is the speed at which airflow over an aircraft’s wing reaches the speed of sound. It marks the boundary between subsonic and transonic flow regimes. Exceeding this critical speed can lead to aerodynamic instabilities and performance issues. It’s a crucial parameter in aircraft design, helping engineers ensure safe and efficient flight across a range of speeds. The critical Mach number () can be calculated using the formula:
Where:
- is the Critical Mach number (dimensionless).
- is the Drag coefficient at zero lift (dimensionless).
- is the lift-induced drag factor (dimensionless).
- is the lift coefficient (dimensionless).
- W/S is the wing loading in N/m2