Which consequence is most likely when a rotating turbine is driven through its natural frequency?

• A. Turbine will accelerate uncontrollably
• B. Turbine will stall
• C. Turbine will vibrate violently
• D. Turbine will overheat

Answer: (C)

Resonance in rotating machinery happens when the driving force excites a natural mode of the turbine. When the system is driven through that natural frequency, energy is transferred very efficiently into that vibrational mode. With finite damping, the vibration amplitude grows, so the turbine tends to vibrate with large, even violent, oscillations. That’s the immediate consequence you’d expect because the structure is being pushed at its own natural rhythm, piling energy into motion instead of quickly damping it out. Stalling or overheating aren’t the direct outcomes of this resonance phenomenon, though extreme vibration can contribute to mechanical stress and warming over time.