afterburner (engine)

For other uses of afterburner, see Afterburner (disambiguation). An afterburner is an additional component added to some jet engines, primarily those on military aircraft.

Design

The jet engine afterburner is an extended exhaust section containing extra fuel injector nozzles. When the afterburner is turned on, fuel is injected and ignites immediately due to the high temperature of the exhaust gases. This combustion results in a very large release of hot exhaust, which expands and produces extra engine thrust.

Limitations

Due to their high fuel consumption, afterburners are not used for extended periods. Thus, they are only used when it is important to have as much thrust as possible. This includes takeoffs from short runways (as on an aircraft carrier) and air combat situations.

Efficiency

One should note that since the exhaust gas already has reduced oxygen due to previous combustion, and since the fuel is not burning in a highly compressed air column, it is quite inefficient. Afterburners do produce markedly enhanced thrust as well as (typically) a very large, impressive flame at the back of the engine.

Usage

The only civilian aircraft to use afterburners were Concorde and the Tupolev Tu-144 supersonic passenger aircraft. The development of supercruise engines has lessened the need for afterburner use.