Engines and their Systems (inc. Turbo, Supercharger, Exhaust...)
Diesel Engine - How it works
The diesel engine (also known as a compression-ignition or CI engine) is an internal combustion engine in which ignition of the fuel that has been injected into the combustion chamber is initiated by the high temperature which a gas achieves when greatly compressed (adiabatic compression). This contrasts with spark-ignition engines such as a petrol engine (gasoline engine) or gas engine (using a gaseous fuel as opposed to petrol), which use a spark plug to ignite an air-fuel mixture.
The compression-ignition engine has the highest thermal efficiency (engine efficiency) of any practical internal or external combustion engine due to its very high expansion ratio and inherent lean burn which enables heat dissipation by the excess air .
How a Turbocharger works
A turbocharger, is a turbine-driven forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra air into the combustion chamber. This improvement over a naturally aspirated engine's power output is because the turbine can force more air - and proportionately more fuel - into the combustion chamber than atmospheric pressure alone.
Turbochargers were originally known as turbosuperchargers when all forced induction devices were classified as superchargers.
A turbocharger is powered by a turbine driven by the engine's exhaust gas. Compared to a mechanically driven supercharger, turbochargers tend to be more efficient, but less responsive
How a Supercharger Works
A supercharger, is an engine driven compressor used as a forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra air into the combustion chamber. This improvement over a naturally aspirated engine's power output is because the turbine can force more air - and proportionately more fuel - into the combustion chamber than atmospheric pressure alone.
Power for the supercharger can be provided mechanically by means of a belt, gear, shaft, or chain connected to the engine's crankshaft.
Dual Mass Flywheels - What are they?
A Dual mass flywheel or DMF is a rotating mechanical device that is used to provide continuous energy (rotational energy) in systems where the energy source is not continuous, such as an engine running at low revs. This works in the same way as a conventional flywheel acts, but damping any violent variation of torque or revolutions that could cause an unwanted vibration.
The vibration reduction is achieved by accumulating stored energy in the two flywheel half masses over a period of time but damped by a series of strong springs, doing that at a rate that is compatible with the energy source, and then releasing that energy at a much higher rate over a relatively short time.
Diesel Exhaust Fluid (DEF) - How it works
A Selective Catalytic Reduction (SCR) system reduces levels of NOx (oxides of nitrogen emitted from engines) that are harmful to our health and the environment. SCR is the aftertreatment technology that treats exhaust gas downstream of the engine. Small quantities of diesel exhaust fluid (DEF) are injected into the exhaust upstream of a catalyst, where it vaporizes and decomposes to form ammonia and carbon dioxide. The ammonia (NH3) is the desired product which in conjunction to the SCR catalyst, converts the NOx to harmless nitrogen (N2) and water (H2O).