What function does an afterburner serve in some gas turbine engines?

An afterburner is an important component of certain gas turbine engines, particularly in military jets and supersonic aircraft. Its primary function is to increase thrust by injecting additional fuel into the exhaust stream. When fuel is introduced into the hot exhaust gases and ignited, it combusts, significantly increasing the volume and velocity of the exhaust gases that are expelled. This results in a boost in thrust, making it ideal for applications requiring rapid acceleration or high-speed performance.

The process enhances the engine's overall performance during specific phases of flight, such as takeoff and combat situations, where additional power is necessary. The afterburner provides an effective means of augmenting thrust without the need for extensive modifications to the core engine design.

While other functions listed, such as cooling the turbine or enhancing fuel efficiency during cruising, may be relevant to different components of a gas turbine engine, they do not pertain to the role of an afterburner. Additionally, filtering exhaust emissions is more closely associated with other engine technologies and not the design or purpose of afterburners.