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Where does mixing of fuel and air take place in case of diesel engine?

Where does mixing of fuel and air take place in case of diesel engine? Correct Answer Engine cylinder

Explanation:

In diesel engines, only air is sent into the combustion chamber during induction. This air is compressed during the compression stroke and towards the end of the compression stroke, fuel is injected by the fuel injection system into the cylinder - just before the desired start of combustion. Liquid fuel is injected at high velocities as one or more jets through small orifices or nozzles in the injector tip.

Since the air temperature and pressure are above the fuel’s ignition point, spontaneous ignition of portions of already mixed fuel and air occurs after a delay period of a few crank angle degrees.

So, in the case of diesel engine, mixing of fuel and air takes place in the Engine cylinder.

Important Point:

There are certain basic differences existing between the combustion process in the SI and CI engines.

In SI Engines, a homogeneous carburetted mixture of gasoline and air, in a certain proportion, is compressed (Compression ratio 6 : 1 to 10 : 1) and the mixture is ignited at one place before the end of the compression stroke by mean of an electric spark (Spark plug). A single flame front progresses through the air-fuel mixture after ignition.

In the CI engine, only air is compressed through a high compression ratio (16 : 1 to 20 : 1), raising its temperature and pressure to a high value. Fuel is injected through one or more jets into this highly compressed air in the combustion chamber.

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