The critical speed of rotation in the context of aircraft design is the speed at which a rotating component, such as a propeller or rotor, begins to experience resonance or excessive vibration. This critical speed is important to prevent structural failures and maintain the safety and integrity of the aircraft.
The formula to calculate the critical speed of rotation (Nc) for a rotating component is as follows:
- Nc is the critical speed of rotation in revolutions per minute (RPM).
- π (pi) is approximately 3.14159.
- K is the stiffness of the rotating component or system (in newton-meters per radian, N·m/rad).
- I is the moment of inertia of the rotating component or system (in kilogram-meters squared, kg·m²).