| TurbochargerThe turbocharger is the most commonly used form of forced induction system in motor vehicle engines.
Turbochargers increase the air throughput of an engine by compressing the air required for combustion. Compared with a naturally aspirated engine with the same displacement, a turbocharged engine can produce higher power and torque, as well as being more efficient.
A turbocharger is powered by the energy contained in the exhaust gas. It consists of two turbines. The turbine wheel is located in the exhaust stream and drives a compressor wheel connected by a shaft. The compressor wheel compresses the air to a relative pressure of up to 1.5 bar. The air heated by the compression process is usually cooled by means of a charge air cooler, and then fed to the combustion chamber. Cool air takes up less space than hot air. Charge air cooling thus allows more oxygen for combustion to enter the combustion chamber.
Depending on the engine concept, some of the very high-performance engines used in Volkswagen vehicles have two turbochargers (biturbo), such as the V10 TDI.
In the past, increased power was the main reason for using a turbocharger, but today energy savings and reduced emissions are the primary reasons, along with enhanced pulling power. Today, turbochargers that alter their blade settings according to the engine load are widely used, and not only in diesel engines. These are known as chargers with variable turbine geometry. |
