volumetric efficiency


Also found in: Dictionary, Acronyms, Wikipedia.

volumetric efficiency

[¦väl·yə¦me·trik i′fish·ən·sē]
(mechanical engineering)
In describing an engine or gas compressor, the ratio of volume of working substance actually admitted, measured at a specified temperature and pressure, to the full piston displacement volume; for a liquid-fuel engine, such as a diesel engine, volumetric efficiency is the ratio of the volume of air drawn into a cylinder to the piston displacement.
References in periodicals archive ?
at rated power, the rail pressure should be kept at the maximum value to curtail the total injection duration so that the injection window can stay within the allowable range of timing and maintains the flexibility of being postponed relative to the IVC for volumetric efficiency gain, if necessary.
This is in congruence with the theory, as with increase in load the back flow through the leakage gaps increases, thus decreasing its volumetric efficiency.
Injected fuel that evaporates after the intake valve closes further cools and increases the density of the trapped air charge, but cannot impact volumetric efficiency.
Tying this in with advances in manufacturing technology, such as improved registration for electrode laydown and improved margin alignment, has enabled major advances with respect to capacitor volumetric efficiency.
The volumetric efficiency depends greatly on the compression pressure ratio, polytropic index (n = [c.
Screw compressors may currently have a large market share but when it comes to energy efficiency, operating speeds, volumetric efficiency, wear and maintenance it seems vane compressors offer advantages.
While R32 and L41A resulted in lower isentropic efficiency and volumetric efficiency than those of R410A, D2Y60 resulted in lower isentropic compressor efficiency and higher volumetric compressor efficiency than R410A.
A vastly improved volumetric efficiency is said to make it possible to operate at reduced rpm, shear rates and temperatures, and consequently a narrower residence time distribution.
To obtain a model for the normal behavior the measured volumetric efficiency is identified by a local linear net (LOLIMOT) model and represented as a look-up table.
Therefore, the volumetric efficiency of the cylinder at a given environmental temperature and pressure is defined by the following equation (Heywood 1988):
The airflow to each cylinder is determined by the volumetric efficiency of each cylinder and is, in no way, related to the fuel injection system.
With device volumetric efficiency a key concern for system makers, WD began shipping 7mm height hard drives for thin-profile notebooks earlier this year.