Exam Question
Explain how sluggish action of the suction and delivery valves reduces the volumetric efficiency of an air compressor. (16)
Class 4 (4th Engineer)
MEKM
📅 Oct 2025
Reference Answer
The volumetric efficiency of an air compressor is a critical performance parameter, representing the ratio of the actual volume of free air delivered per unit time to the theoretical swept volume of the cylinder per unit time. Sluggish action of the suction and delivery valves directly impedes this efficiency by disrupting the ideal gas exchange process within the cylinder.
$$ \eta_v = \frac{Actual~Volume~of~Free~Air~Delivered}{Swept~Volume~of~Cylinder} $$
**1. Ideal Valve Operation:**
For optimal volumetric efficiency, valves should operate instantaneously and precisely:
$$ \eta_v = \frac{Actual~Volume~of~Free~Air~Delivered}{Swept~Volume~of~Cylinder} $$
**1. Ideal Valve Operation:**
For optimal volumetric efficiency, valves should operate instantaneously and precisely:
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