Critical speed in diesel engines occurs when...

Question 1 / 270705eccefa1bacbc34ba4d475e1

Question 1 of 270705eccefa1bacbc34ba4d475e1

Critical speed in diesel engines occurs when engine torque pulsations become __________.

Question 1 of 27070

Critical speed in diesel engines occurs when engine torque pulsations become __________.

🔍 Key Concepts

• Critical speed of rotating machinery (what it means physically) • Relationship between forcing frequency (torque pulsations) and natural frequency of a shaft or crankshaft • How resonance affects vibration amplitude in marine diesel engine crankshafts

💭 Think About

• Ask yourself: At what condition do small, repeated torque pulsations build up into very large crankshaft vibrations? • Which choice describes a situation where the crankshaft’s own tendency to vibrate lines up with the engine’s torque pulses? • Which answers are just describing TYPES of motion, and which answer is describing the specific CONDITION that creates critical speed?

✅ Before You Answer

• Be clear on the definition of critical speed in rotating machinery – it’s tied to a specific frequency relationship, not just any vibration. • Identify which option mentions a natural frequency or an equivalent idea of the shaft’s own vibration rate. • Check which choices merely name vibration directions or modes (fore‑and‑aft, whipping, rocking) without specifying the underlying resonance condition.

Question 1 of 27070

Critical speed in diesel engines occurs when engine torque pulsations become __________.

opposed to the crankshaft rocking couple

resonant with the crankshaft natural frequency

critical fore and aft crankshaft vibrations

horizontal whipping motions of the crankshaft

Question 1 / 270705eccefa1bacbc34ba4d475e1

Question 1 of 270705eccefa1bacbc34ba4d475e1

Critical speed in diesel engines occurs when engine torque pulsations become __________.

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Question 1 of 27070

Critical speed in diesel engines occurs when engine torque pulsations become __________.