A turbojet engine sucks air into the front of the engine, compresses it and forces it into a combustion chamber. Fuel sprays into the compressed air here and is ignited. The ignited gases rush out of the exhaust nozzle of the engine and propel it forward. The heated gases also spin the turbine which is attached to the compressor and is used to continuously compress more air for engine operation.
All turbojet engines share the same basic parts, though some may have additional components. An intake collects air at the front of the engine, and a compressor made up of multiple stages of blades compresses the air. The combustor adds and ignites fuel that is pushed rearward through the engine, turning a turbine. The turbine is connected to the compressor blades by a shaft so that when the turbine turns the compressor also turns. The ignited gases are finally expelled through the rear of the engine nozzle at very high speeds .
The turbojet is one of the simplest jet engines and was used on many early military and civilian jet aircraft. Advances in jet technology have led to the turbofan engine's replacing the turbojet in most applications.
The turbojet is among the simplest of jet engines. Newer jet engines have become more efficient and quieter during operation. These are two reasons why turbojet engines are rarely used today, especially in commercial applications where noise and fuel efficiency may be carefully monitored and regulated.
One common component on some military turbojets is the afterburner. The afterburner simply adds fuel to the jet's hot exhaust. The fuel provides extra thrust as it ignites but does so very inefficiently. Modern turbofan engines can also be equipped with afterburners, but the most advanced jet engines can reach very high speeds without the use of afterburners at all.
