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(mechanical engineering)
A method of introducing air for combustion into the cylinder of an internal combustion engine at a pressure in excess of that which can be obtained by natural aspiration.



an increase in the quantity of the fresh charge of a combustible mixture that is supplied to an internal-combustion engine by raising the intake pressure. Supercharging is usually used to increase power by 20–45 percent without increasing the weight and size of the engine, and also to compensate for loss of power under high-altitude conditions. Supercharging with “quality control” can be used to “purify” the process—that is, to reduce the toxicity and smokiness of the exhaust gases.

A supercharger unit uses a compressor, a turbocompressor, or a combination of the two. The most common type has a turbo-compressor driven by energy from the exhaust gases. Supercharger assemblies are used on almost all forms of vehicle dieseis (marine, locomotive, and tractor engines); in carburetor engines supercharging is limited by the onset of detonation. Among the main drawbacks of a supercharger assembly are increased mechanical and thermal stresses on the engine (caused by the higher pressure and temperature of the gases), reduced economy, and increased complexity of design.

The “built-in” superchargers include the dynamic type (formerly called the inertia, resonance, or acoustic type), in which the effect is obtained by means of vibratory phenomena in pipes; the ram type, which is used in piston aircraft engines at altitudes above the rated altitude and speeds above 500 km/hr; and the refrigeration superchargers, which achieve the effect by evaporating into the air supply a fuel or other combustible fluid with a low boiling point and a high heat of vaporization.

Dynamic supercharging, which can raise the admission coefficient ƞv, to 0.92–0.96 over a wide range of engine speeds with minor changes in the manifold design, is becoming increasingly common in vehicle internal-combustion engines. An increase in ƞv, by supercharging makes it possible to boost a diesel engine’s power when the fuel feed per cycle is increased or to improve economy while maintaining power (with the same fuel feed per cycle). Dynamic supercharging increases the life of components in the cylinder-piston group because of lower temperatures when operating on lean mixtures.


References in periodicals archive ?
These challenges notwithstanding, companies have been making significant headway in supercharging technology, rolling out many cutting-edge products.
Once customers use up all their free Supercharging credits, they will be billed on their credit card registered with the Tesla website.
The free charging along the Supercharging network will enable Tesla owners to travel along the highways from coast to coast in North America by the year end, Tesla said and also that these Superchargers provide half a charge in about 20 minutes.
On engines required to operate at altitudes sufficient to cause a power drop to less than sea-level output, supercharging can compensate for the loss of air density by forcing a larger volume of air into the cylinder.
The supercharging system is provided from Eaton's Twin Vortices Series, which features Roots-type positive displacement design, with two four-lobe rotors that are twisted at 160 degrees.
Tesla has been investing heavily in building supercharging stations, and said it will have more than 100 locations by the end of the year, allowing drivers to drive a Tesla car from Los Angeles to New York.