Volumetric efficiency application (single cylinder gas engine): A gas engine has a swept volume of 300 cm³ and a clearance volume of 25 cm³. If the volumetric efficiency is 0.88 and mechanical efficiency is 0.90, determine the actual volume of fresh mixture taken in per stroke (at the same reference conditions used for defining volumetric efficiency).

Introduction / Context:
Volumetric efficiency measures how effectively the cylinder is filled with fresh charge compared to its swept volume. It is central to intake tuning, breathing analysis, and performance estimation in both SI and CI engines.

Given Data / Assumptions:

• Swept volume Vs = 300 cm³.
• Clearance volume Vc = 25 cm³ (not directly used in this basic computation).
• Volumetric efficiency η_v = 0.88.
• Mechanical efficiency η_m = 0.90 (irrelevant for volumetric calculation).

Concept / Approach:
By definition (at a specified reference state), η_v = (actual volume of fresh charge inducted per cycle) / (swept volume). Therefore, the inducted mixture volume per stroke equals η_v * Vs. Mechanical efficiency relates brake to indicated power and does not enter this calculation.

Step-by-Step Solution:

Verification / Alternative check:
If η_v were 100%, the engine would induct 300 cm³ per stroke. Since η_v is 88%, the result must be slightly less than 300 cm³, which 264 cm³ satisfies.

Why Other Options Are Wrong:

• 248 cm³ / 252 cm³: Do not match 0.88 * 300.
• 286 cm³: Exceeds 0.95 of the swept volume and is inconsistent with η_v = 0.88.

Common Pitfalls:
Confusing volumetric efficiency (based on swept volume) with total cylinder volume (swept + clearance). Also, mechanical efficiency is unrelated to inducted volume.

Final Answer:
264 cm³