What occurs when a steam turbine reaches critical speed?

When a steam turbine reaches critical speed, it experiences a condition where the rotational speed matches its natural frequency. At this point, the turbine can start to vibrate violently due to resonance, which can lead to significant mechanical stress and potential damage to the turbine components. These vibrations occur because the forces acting on the turbine are amplified at this specific speed, which is often referred to as the critical speed.

Understanding critical speed is crucial for the safe and efficient operation of turbines. Engineers design turbines with certain margins to avoid operating close to their critical speeds, ensuring stability and longevity. Recognizing the potential for violent vibrations helps operators take preventive measures to avoid such scenarios, safeguarding both personnel and equipment.