How Turbojet Engine Works
How turbojet engine works. Do you ever notice the sound came out during you fly with an aircraft? Yes, that is the turbine engine’s sound. The aircraft engine is vital part in the aircraft. The engine produces thrust that pull an aircraft to fly, working together with the ‘lift force’ generated by wings.
Aircraft engine should perfectly work for hours during the flight. In total might be hundreds even thousands of hours without malfunction in various condition and weather.
Here is animation shown the works of turbojet engine mechanically.
Animation by Animagraffs
There are three main components in turbine engine, especially in turbojet engine. Those are Compressor, Combustion Chamber and Turbine. In other hand, we also have intake and exhaust in the beginning and rear-end of the engine.
In simple ways, understanding of turbojet engines can be follow as:
The main role of the compressor is increasing pressure as well as pressure of the air. Whole air entered from intake will be enhanced by compressor. Compressor can do this kind of things because compressor has many shaped-blades encircled with special airfoil profile.
After processed by the compressor, enhanced air then enter the combustion chamber. High temperature air from compressor will partially mixed with fuel then ignited.
The other partial air is cooling the combustion chamber, the main goal is keeping air-fuel ratio is enough and efficient, not too richor not too lean. The basic idea is same with conventional gasoline engine.
Turbojet Engine Layout and Stages
Once the gaseous mixture exit from combustion chamber then enter final stage of turbojet engine. The objective in last stage is moving the high pressure turbine to power compressor’s shaft and supplying aircraft’s electronic needs. The remain gaseous will be expanded by the low-pressure turbine, leaving engine as a thrust.
The turbojet engine is an old-fashioned aircraft engine after the piston engine in pre-WWII. Currently most modern aircraft use turbofan engines for propulsion systems since the turbofan has better fuel efficiency as well as higher thrust performance.
Turbofan engine is quiet similar with turbojet engine, the turbine-based engine concept.
The only differences are the core of engine (compressor, combustion, turbine) surrounded by a fan systems and additional turbine shaft at the rear-end of the engine. Some literature say that the turbofan is a two-spool engine in the turbojet engine only has one-spool engine. The two-spool refer to double shaft that connect core-shaft and fan-shaft.
Nowadays, most advanced engines even have more spool on its engine’s nacelles.
Turbofan Engine Mechanism
Turbofan works in similar way with turbojet engine, part of incoming air entered to the engine inlet and pass through compressor, combustion and turbine, obtaining hot gases as thrust. Some other part of air passes through the fan and by-passing till the rear-end of the engine nacelles.
Its air’s velocity increased as pass the shaped-fan and pressure gradient. The ratio of air passed through core and fan is a bypass ratio.
The bypass ratio used as indicator in order of engine’s selection. How turbojet engine works was simple yet complex. Scientist are keep on research how to make it more efficient and greener.