is the ratio of the weight of air drawn into the cylinder
of an operating internal
combustion engine to the weight of air the cylinder could hold at rest
when the piston is at the bottom of the stroke and the valves are fully
closed. Any restriction of air flow into the cylinder reduces volumetric
efficiency, which, in turn, reduces power output. The volumetric efficiency
of an automotive engine is usually slightly more than 80% at about half the
rated speed of the engine, then decreases considerably at higher speed, thus
limiting the power output of the engine. The air charge to the cylinder can
be increased at high speeds by means of supercharging.
Also see supercharger.
Application
Notes:
