What is Scavenging?

Scavenging is the process used in IC engines in which the burnt gases are forced or pushed to atmosphere from the engine cylinder by using the inlet pressure of fresh air.

Importance and Causes of Scavenging:

If the burnt gases inside the engine cylinder are not completely exhausted, then the following incidents will happen:

Already burnt gases will be compressed again during the compression stroke if they are left inside the cylinder.

This causes the temperature of air fuel mixture to exceed the maximum temperature as the burnt gases have already some temperature because of burning.

Because of this maximum temperature, the fuel can burn before the power stroke, so this tends to abnormal combustion.

We know that, the abnormal combustion causes the knocking phenomenon.