SSANGYONG Korando 2012 Manual page 319

c. Types of swirl
d. Swirl control
In DI type diesel engine, the liquefied fuel is injected into the cylinder directly. If the fuel is evenly
distributed in short period, the combustion efficiency could be improved. To get this, there should
be good air flow in cylinder. In general, there are two intake ports, swirl port and tangential port,
in each cylinder. The swirl port generates the horizontal flow and the tangential port generates the
longitudinal flow.
In low/mid load range, the tabgential port is closed to increase the horizontal flow. Fast flow
decreases the PM during combustion and increases the EGR ratio by better combustion
efficiency.
Swirl: One cylinder has two intake air ports, one is set
horizontally and the other one is set vertically. Swirl is the
horizontal air flows in cylinder due to the horizontal intake air
ports.
Tumble: Tumble is the vertical air flows in cylinder due to the
vertical intake air port
Squish: Squish is the air flows due to the piston head. Normally,
this is appears at the final process of compression. In CRDi
engine, the piston head creates the bowl type squish.
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