What is calculated using the ratio of air drawn into the cylinder to the piston displacement?

What is calculated using the ratio of air drawn into the cylinder to the piston displacement?

• A. Thermal Efficiency
• B. Fuel Efficiency
• C. Volume Metric Efficiency
• D. Mechanical Efficiency

Answer: (C)

Volumetric efficiency measures how well an engine fills its cylinders with air. It is the ratio of the actual air drawn into the cylinder during the intake stroke to the cylinder’s displacement (the amount the cylinder would hold if it were fully filled). This tells you how effectively the engine uses its swept volume to admit air for combustion. If the engine pulls air nearly equal to the displacement, volumetric efficiency is high; if air flow is restricted, it’s lower. This concept is distinct from thermal efficiency (how effectively heat energy from fuel is converted to work), fuel efficiency (fuel used per distance or per unit of power), and mechanical efficiency (how much useful work is lost to friction).

Volumetric efficiency measures how well an engine fills its cylinders with air. It is the ratio of the actual air drawn into the cylinder during the intake stroke to the cylinder’s displacement (the amount the cylinder would hold if it were fully filled). This tells you how effectively the engine uses its swept volume to admit air for combustion. If the engine pulls air nearly equal to the displacement, volumetric efficiency is high; if air flow is restricted, it’s lower.

This concept is distinct from thermal efficiency (how effectively heat energy from fuel is converted to work), fuel efficiency (fuel used per distance or per unit of power), and mechanical efficiency (how much useful work is lost to friction).