Afterburner (engine)

An afterburner is an additional component added to some jet engines, primarily those on military aircraft.

Table of contents

1 Design
2 Limitations
3 Efficiency
4 Usage

Design

On a jet engine with an afterburner, the engine exhaust tubing is extended and contains extra fuel injector nozzles. This section is the afterburner. When the fuel is turned on, it ignites immediately due to high heat. This combustion results in a very large release of hot exhaust, which expands and produces extra engine thrust.

Limitations

Afterburners are dangerous to use for extended periods because the high heat can melt engine components. Thus, they are only used for limited times where it is very important to have as much thrust as absolutely possible. This includes both takeoffs from short runways (as in on an aircraft carrier), or during air combat situations.

Efficiency

One should note that since the exhaust gas already has reduced oxygen due to previous combusion, 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 using afterburners is the Concorde. In addition, development of supercruise engines has lessened the need for afterburner use.