Diesel engine operation
Combustion in diesel engines

Regardless of the type of diesel engine, we are dealing with :

• compression ignition, possibly assisted by devices (e.g. air intake heating or glow plugs);

• diffusion combustion, i.e. separate introduction of air and fuel into the cylinder, with combustion controlled by the air + fuel mixture.

Whether the engine is a 2-stroke or a 4-stroke, and whether or not it is supercharged, the cylinder is filled with fresh air at each cycle, without the need for a throttle valve. This air is compressed with a high volumetric ratio so as to obtain, despite heat losses at the walls, an end-of-compression temperature higher than the auto-ignition temperature of the fuel used.

In the vicinity of top dead center (TDC), fuel is injected in the form of one or more jets,...