Search results
Results From The WOW.Com Content Network
To achieve higher power outputs at the same speed, more fuel must be burned and therefore more air is needed. To achieve this, turbochargers or superchargers are used to increase the inlet pressure. This would result in detonation of the fuel/air mixture unless the compression ratio was decreased, i.e. the volume above the piston made greater.
Variable-geometry turbochargers (also known as variable-nozzle turbochargers) are used to alter the effective aspect ratio of the turbocharger as operating conditions change. This is done with the use of adjustable vanes located inside the turbine housing between the inlet and turbine, which affect flow of gases towards the turbine.
A turbocharger for a car engine A supercharger (on top of a dark-grey inlet manifold) for a car engine. In an internal combustion engine, forced induction is where turbocharging or supercharging is used to increase the density of the intake air.
Modern turbo-diesel engines use electronically controlled common-rail fuel injection to increase efficiency. With the help of geometrically variable turbo-charging system (albeit more maintenance) this also increases the engines' torque at low engine speeds (1,200–1,800 rpm).
Diesel engines are typically well suited to turbocharging due to two factors: A "lean" air–fuel ratio, caused when the turbocharger supplies excess air into the engine, is not a problem for diesel engines, because the torque control is dependent on the mass of fuel that is injected into the combustion chamber (i.e. air-fuel ratio), rather than the quantity of the air-fuel mixture.
Variable-geometry turbochargers (VGTs), occasionally known as variable-nozzle turbochargers (VNTs), are a type of turbochargers, usually designed to allow the effective aspect ratio (A/R ratio) of the turbocharger to be altered as conditions change. This is done with the use of adjustable vanes located inside the turbine housing between the ...
A turbo-compound engine is a reciprocating engine that employs a turbine to recover energy from the exhaust gases. Instead of using that energy to drive a turbocharger as found in many high-power aircraft engines , the energy is instead sent to the output shaft to increase the total power delivered by the engine.
Together, these parameters tend to increase core thermal efficiency and improve fuel efficiency. Some high-bypass-ratio civil turbofans use an extremely low area ratio (less than 1.01), convergent-divergent, nozzle on the bypass (or mixed exhaust) stream, to control the fan working line. The nozzle acts as if it has variable geometry.