It is difficult to imagine the modern world without airplanes. Aviation has become a part of our life and helps travelers to cover thousands of kilometers in a matter of hours, which, in the recent past, seemed fantastic. Not to mention space flights and travel to distant planets. All this became possible thanks to the invention of jet engines. Let's take a look at how they work.
The first motors appeared a long time ago and converted the muscular strength of animals into energy useful for achieving a specific goal. The simplest example is a horse helping to turn Eernov's mills. Then there were windmills, where millstones were set in motion by wind energy, or water mills that use the flow of rivers.
Fuel fueled engines
Society immediately appreciated the advantages of using the simplest engines, and in subsequent years, many scientists worked on the development of models, the work of which would not depend on natural and weather conditions, the fatigue of an animal acting as a source of energy.
Huygens van Zeilichem
The greatest success in this field was achieved by the Dutch physicist Christian Huygens van Zeilichem, who in 1687 was the first to propose the use of gunpowder as a source of energy. According to the concept, an internal combustion chamber was created in the engine, in which gunpowder was to be burned, and the energy released as a result of combustion was converted into a force that sets a certain element in motion. Gunpowder was the first prototype of modern fuel.
It is noteworthy that the idea was borrowed from the gunners, watching whom Huygens drew attention to the fact that after the shot, the guns rolled back in the direction opposite to the shot.
The achievements of the Dutchman, as well as of a number of other distinguished scientists, greatly facilitated the way of creating fuel engines that we still use today. In place of gunpowder came gasoline and diesel fuel, which have different physical properties and combustion temperatures required to release energy.
As time went on, science did not stand still. The simplest mechanical engines were replaced by steam, fuel, and electric.
But scientific research and development did not stop there. As always, nature came to the rescue, which, in most cases, pushes inventors to amazing discoveries.
Observations of marine life such as octopus, squid and cuttlefish have led to unexpected results. The manner of movement of these marine inhabitants was similar to a short-term push. As if the body is being pushed away from something and moving forward.
These observations were somewhat similar to Huegens' remarks about the shot and the cannon, which we mentioned above.
Thus, the concept of "recoil phenomenon" appeared in physics. In the course of further scientific research, it was found that it is thanks to the phenomenon of recoil that all movement on planet Earth occurs: a car is repelled from the earth, a ship - from water, etc.
The movement of bodies occurs due to the transfer of impulse from one object to another. To explain the phenomenon, we will give the simplest example: you decided to push your friend on the shoulder, applied a certain force, as a result of which, he moved from his place, but you also experienced a force pushing you in the opposite direction.
Of course, the distance you and your friend move will depend on a number of factors: how much you weigh, how hard you pushed him.
Jet engine and how it works
Thus, we gradually came to the consideration of the most common type of engine in the aircraft and rocket industry - a jet engine.
Any of us is able to personally observe the phenomenon of a reactive reaction. All that is needed is to inflate the balloon and release. Everyone knows what will happen next: a stream of air will burst out of the ball, which will move the body of the ball in the opposite direction.
Agree, it is very similar to how a squid, by contracting its muscles, creates a stream of water pushing it in the opposite direction.
The observations described above received precise scientific explanations, were reflected in physical laws:
- momentum conservation law;
- Newton's third law.
It is on them that the principle of operation of a jet engine is based: an air stream enters the engine, which burns in the internal combustion chamber, mixing with fuel, as a result of which a jet stream is formed, forcing the body to move forward.
The principle of operation is quite simple, however, the device of such an engine is rather complicated and requires the most accurate calculations.
Jet engine device
A jet engine consists of the following main elements:
- compressor that draws air into the engine;
- an internal combustion chamber where fuel and air are mixed and burned;
- turbine - gives additional acceleration to the flow of thermal energy obtained as a result of combustion of fuel and air;
- nozzle, the most important element that converts internal energy into "driving force" - kinetic energy.
Thanks to the joint interaction of these elements, a powerful jet stream is formed at the output of the jet engine, giving the objects on which the engine is installed the highest speed.
Jet engines in aircraft
On the eve of World War, scientists from leading countries worked diligently on the development of aircraft with jet engines that would allow their countries to unconditionally dictate their terms on the heavenly front.
The first jet aircraft was developed by the Germans in 1937, and its tests began only in 1939. However, the engines available at that time consumed an incredibly large amount of fuel and the range of such an aircraft was only 60 km.
At the same time, Japan and Great Britain managed to create their own aircraft with jet engines. But these were only prototypes that never entered mass production.
The first serial jet aircraft was the German Messerschmitt, which, however, did not allow the Hitlerite coalition to gain the upper hand in the war unleashed by them.
Messerschmitt Me-262 Schwalbe / Sturmvogel
In civil aviation, jet aircraft appeared only in 1952 in Great Britain.
Since then and to the present day, jet engines have been the main engines used in aircraft construction. It is thanks to them that modern liners develop speeds of up to 800 kilometers per hour.
Jet engines in space
After the conquest of the sky, mankind set itself the task of conquering space.
As you already understood, the most powerful engine capable of lifting a rocket to an altitude of many thousands of kilometers was precisely the jet engine.
Of course, the question arises: how can a jet engine work in space, in airless space?
An oxygen reservoir is provided in the rocket device, which mixes with the rocket fuel and forms the necessary thrust of the rocket flight when the spacecraft leaves the Earth's atmosphere.
Then the law of conservation of momentum comes into play: the mass of the rocket gradually decreases, the burnt mixture of fuel and oxygen is thrown out through the nozzle in one direction, and the body of the rocket moves in the opposite direction.