Compressor efficiencies: identify the ratio IP/BP For a compressor driven by a prime mover, consider the ratio of indicated power (IP) to the shaft/brake power (BP) supplied to the compressor. What is this efficiency called? Choose the correct term.
Mechanical Engineering
Compressors, Gas Dynamics and Gas Turbines
Difficulty: Easy
Choose an option
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ACompressor (overall) efficiency
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BVolumetric efficiency
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CIsothermal efficiency
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DMechanical efficiency
Answer
Correct Answer: Mechanical efficiency
Explanation
Concept/ApproachMechanical efficiency of a compressor quantifies how effectively the input shaft (brake) power is converted into indicated power within the cylinder, i.e., ηmech = IP / BP.
Notes
- Volumetric efficiency relates to the mass (or volume) actually inducted vs. swept volume.
- Isothermal efficiency compares actual compression work to ideal isothermal work.
- Overall/compressor efficiency aggregates multiple effects; it is not simply IP/BP.
Final AnswerMechanical efficiency