Definition check — volumetric efficiency: Is volumetric efficiency correctly defined as the ratio of free-air volume delivered per stroke to the piston’s swept volume?

Introduction / Context:
Volumetric efficiency links what a reciprocating compressor geometrically displaces to how much fresh charge it truly admits and delivers, referred to a common basis (free air). The definition must be precise to compare cylinders with different clearances and valve characteristics.

Given Data / Assumptions:

• Swept volume is the piston displacement per stroke.
• Delivered volume is converted to free-air basis (ambient pressure and temperature).
• Single-acting cylinder considered for simplicity.

Concept / Approach:

Volumetric efficiency, η_v, quantifies cylinder filling: η_v = (free-air volume delivered per stroke) / (swept volume). It accounts for clearance re-expansion and suction losses, allowing meaningful comparison across designs and operating ratios. Because it uses free-air reference, η_v connects directly to mass flow at given ambient conditions.

Step-by-Step Solution:

Verification / Alternative check:

Indicator diagrams and standard test codes adopt this definition; models express η_v in terms of clearance and pressure ratio, reaffirming its basis.

Why Other Options Are Wrong:

“No” would be valid only if delivery were not converted to free-air or if a different basis were specified; here, the statement is standard.

Common Pitfalls:

Using discharge-state volume instead of free-air; ignoring temperature differences; confusing volumetric with isentropic efficiency.

Final Answer:

Yes