Turbocharging and supercharging |
Have you driven the tata vehicles lately? Driven an Octavia RS? Ever heard that whistle while those huge trucks with TC written on them go by? Ever wondered what it was?
There is a very simple saying during the design of engines, especially diesel engines; more the air you pump, the more the power you get. Basically, in an internal combustion engine, air and fuel is mixed in a specific ratio, in a diesel engine only air is pumped into the engine and then fuel is atomised in the engine due to high pressure.
That said, what exactly is this turbocharger? Well, you might have noticed that exhaust gases in an engine is hot and has some amount of speed too. Engineers decided to utilised this heat and speed of the exhaust gases. The act of using the heat and the speed of the exhaust gases to pump more gases through the inlet is called turbocharging. Thats is actually as simply explained as possible, but thats not as simple as it is. The main design criteria is the amount of turbo boost, which is basically how much of increase in pressure the turbocharger should suppy at the inlet. This causes the engine to produce much more power since it is being supplied with more air and fuel than it possibly could without it. A naturally aspirated engine; one without any pressure building device in the intale manfold, has to "suck" air through the intake manifolds, throttle body, ait filter, and various other elements before it actually enters the combustion chamber. As a result, volumetric effieciency or the amount of air or air fuel mixture(whichever the case may be) is much less than the swept volume of the engine. With the turbocharger or supercharger, air is being blown into the chamber with higher than atmospheric pressure so that much more air and fuel can enter. As much as 10psi pressure can be generated by turbocharged engines.
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![Turbo schematic](javascript:openwin("largephoto.asp?imagename=turbo_schem.jpg&imagetitle=Turbo schematic"))
![Turbo charged intercooled engine](javascript:openwin("largephoto.asp?imagename=turbo_eng.jpg&imagetitle=Turbocharged intercooled engine"))