When I think of the term jet or jet engine, my mind immediately jumps to commercial airlines and combat plane, but did you know that there are several different types of jet engines that all work a little differently? Let's take a look at these different engines.

Turbofan

Turbofan by K. Aainsqatsi – Wikipedia

Most medium to large sized commercial aircraft are equipped with turbofan jet engines, so there is a pretty good chance you've come in contact with a few. In a turbofan engine,  the blades of the fan are used to compress air into the combustion chamber where the compressed air is intermingled with fuel and ignited. The rapidly expanding gasses are jettisoned through the rear of the engine in turn propelling the aircraft forward.

Turboprop

Turboprop byM0tty – Wikipedia

Turboprop engines can often be found on smaller commuter sized airliners that make shorter connection trips between locations. Turboprop engines work very much the same as turbojet engines in that air is being compressed by a fan then mixed with fuel and ignited. The key difference is that the rapidly expanding gas that is created after ignition is being used to spin a turbine that drives the propeller attached to the front of the plane rather than create a stream of air for propulsion.

Turbojet

Turbojet Engine by Jeff Dahl – Wikipedia

A turbojet engine consists of four stages, those stages are: Intake, Compression, Combustion, and Exhaust. There are two sections to a turbojet engine as well, the cold section, and the hot section. In the cold section, air is ingested and compressed by the fans before being passed into the combustion chamber where it is mixed with fuel and ignited by the continuous flame. Once the fuel/air mix is ignited, it is forced out the back of the engine across the turbine the drives the initial compression stage.

Turboshaft

Turboshaft Engine by Emoscopes -Wikipedia

A turboshaft engine functions much like other jet engines, but rather than creating thrust as a form of propulsion, the rapidly expanding air/fuel mixture is used to rotate a shaft. In the aviation field, these engines are used to power some helicopters. Air is ingested into the compressor where it is compressed and mixed with fuel before being ignited and force through the free turbine which rotates the power shaft. 

Ramjet

Ramjet by Cryonic07 – Wikipedia

Think spacecraft. Ramjet engines have no moving parts and work by forcing air through the jet at great speeds. air compression is dependent entirely on forward speed due to the lack of the rotating parts found in a similar turbojet. Due to the nature of this type of engine, takeoff requires an assist from another aircraft to pull the ramjet equipped aircraft fast enough to being generation of useful thrust.