A jet engine can convert into a very powerful pushing force that is known as thrust by using an energy-rich, liquid fuel. By using this thrust, a few numbers of engines can push a plane forward, and then force air past its wings for creating an upward force that is called lift that will finally power it into the sky.
You can visit the website of Flight Literacy, from where you can get a source to know more about jet engines.
How does a jet engine work?
The following are a few steps that are involved in the working of jet engines:
- When a jet engine moves at a speed that is slower as compared to the speed of sound, then the engine speed is about 1000 km/h. At that kind of speed, you can imagine that the engine a stationary object, and only the cold air is moving.
- A fan will be available at the front to suck the cold air and will force it through the inlet. As a result, the speed slows down by 60% and now speed remains 400 km/h.
- There is another fan (compressor) that squeezes the air to increase its pressure almost by 8 times, and that will increase its temperature.
- Kerosene will be squirted into the engine available in the fuel tank.
- Behind the compressor, kerosene will mix with the compressed air to burn fiercely, offering off hot exhaust gases to produce a temperature increase. The temperature of the burning mixture will reach around 900°C (1650°F).
- Then the exhaust gases will rush to turbine blades and spin them like a windmill. As the turbine will gain energy, the gases will lose almost the same energy and they will cool down slightly and also lose pressure.
- A long axle is connected with the turbine blades that will run the engine. The fan and the compressor are also connected with this axle. So, the fan and compressor turn on.
- Through the exhaust nozzle, the hot exhaust gases will exit out of the engine. The exhaust nozzle’s tapering design will help in accelerating the gases to increase the speed to over 2100 km/h.
- The hot air that is leaving the engine at a speed that is twice the cold airspeed entering it from the front-and that powers the plane.
- Often military jets also have an afterburner that will squirt fuel into the exhaust jet for producing extra thrust. These backward-moving exhaust gases will power the jet forward. As the plane is usually much heavier and bigger than the exhaust gases that it produces, so the exhaust gases will zoom backward at a much faster speed than the speed of a plane.
To summerise the above, you may see that each part of the engine will do a different thing with the fuel or air mixture passing through:
Here the air pressure will dramatically increase and, also to a lesser extent the temperature also increases.
This will increase the air-fuel mixture temperature dramatically by releasing heat energy out of the fuel.
This will increase the velocity of exhaust gases dramatically to power the plane.