What are the typical pressure and temperature conditions of air entering a compressor inlet_________________?
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Answer: E. pressure sightly less than atmospheric and temperature slightly more than atmospheric
Explanation
As air is drawn into a compressor through the intake manifold, it must overcome frictional resistance and valve spring forces. This restriction creates a minor pressure drop, leaving the entering air pressure slightly below the surrounding atmospheric pressure. Simultaneously, heat transferred from hot compressor casing walls and inlet valves warms the incoming air slightly above ambient temperature. Volumetric efficiency in compressors is affected negatively by inlet pressure losses and pre-heating of the incoming gas charge. Inlet air density decreases when pressure drops and temperature rises, reducing the total mass flow rate delivered by the compressor. Thermodynamic modeling of reciprocating and rotary compressors uses actual inlet conditions rather than ideal ambient assumptions.
Option A assumes idealized atmospheric conditions without accounting for real-world valve restriction and heat transfer effects. Options B and C capture only half of the thermodynamic reality by ignoring either the pressure drop or the temperature rise. Option D incorrectly states that the temperature is less than atmospheric, which contradicts the warming effect of hot compressor walls.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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