The presence of jet engines was not known in the early 1900s. Therefore, airplanes used primarily engines such as those used in a car (piston engines) to turn their propellers and generate sufficient power to take off. Currently, Jet engines substituted the former piston engines as the primary engine types used in modern aircraft. Jet engines have uses in the military and also commercial airplanes.

So, what is a jet engine? A jet engine is a reaction engine which generates forward motion by expelling high-velocity exhaust gases. The basis for this being possible is Newton’s Third Law which states that for every action, there will be an equal and opposite reaction. In short, the engine inhales air, compresses it to increase pressure, fuels it, burns it, and vents the exhaust to produce thrust to take off.

I referred to piston engines previously, but now you may be wondering what is the difference between a jet engine and a piston engine. To give thrust to raise the plane, piston engines employ rotating propellers, while jet engines can provide continuous thrust. Apart from thrust, jet engines tend to work more effectively at higher altitudes when air is thinner, while piston engines do not work in such conditions. Lastly, based on efficiency, jet engines consume less fuel at higher speeds and altitudes and are still better suited for aviation.

And finally for the moment you have all been waiting for, how do jet engines actually work? Well to begin with, the engine requires air intake and draws in a large quantity of external air. The air enters at the front intake and is routed to the compressor. Compressors then have the responsibility to compress the air to increase the pressure and temperature. This high pressure air is necessary for combustion. Fuel is added to compressed air during the combustion process, and it’s ignited. Burning gas and compressed air mixture expand and start producing very hot high-pressure gases, which impart energy to the airflow. The expanded hot gas passes through the turbine blades, leading to rotating the blades. All the energy isn’t utilized for rotating the turbine but rather comes out the back of the nozzle. Lastly, the leftover gases blast out of the nozzle at extremely high speeds producing forward thrust and propelling the plane ahead. The faster that the exhaust is expelled from the engine, then the greater the thrust will be.

There are currently 4 main forms of jet engines. The turbojet was utilized in most initial fighter planes and certain missiles. It featured a very uncomplicated design but was noisy and less efficient, particularly at slow speeds, that generated all its thrust from its high-speed exhaust. The Turbofan can be found in a lot of commercial jets like the Boeing 737 or Airbus A320. Really, it involves a jet engine core with an enormous fan mounted at the front and the fan blowing additional air around the jet engine core. The Turboprop drives a propeller using a jet engine. It is best for lower speeds on shorter runways and gets the efficiency of a jet with the power of a propeller at subsonic speeds. Lastly, the Scramjet is used in missiles and test aircraft such as the X-43A. It relies primarily on high-speed air to compress the intake air and functions only at supersonic speeds, and my favorite jet engine.

Now, however, there are still a couple of problems with jet engines that continue to threaten society. Jet engines produce an enormous amount of noise pollution, particularly when they take off. Though some more recent designs try to reduce this, it continues to be a major problem at the forefront of aviation. Additionally, the primary problem with jet engines is the burning of jet fuel that injects CO2 into the atmosphere along with other toxins. Additional CO2 in the atmosphere could lead to global warming and climate change that would kill some forms of marine life.