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Jet engine: the principle of operation (briefly). The principle of the jet engine

By reactive means a movement in which one of its parts separates from the body at a certain rate. The force that arises as a result of such a process acts on its own. In other words, she does not even have the slightest contact with external bodies.

Reactive movement in nature

During the summer holiday in the south, almost every one of us, swimming in the sea, met with jellyfish. But few people thought that these animals move in the same way as a jet engine. The principle of operation in the nature of such an aggregate can be observed when certain species of marine plankton and larvae of dragonflies move. And the efficiency of these invertebrates is often higher than that of technical means.

Who else can clearly demonstrate how the jet engine works? Squid, octopus and cuttlefish. A similar movement is performed by many other sea mollusks. Let us take, for example, cuttlefish. She draws water into her gill cavity and ejects it vigorously through the funnel, which is directed backwards or sideways. Thus the mollusc is capable to make movements in the necessary party.

The principle of operation of the jet engine can also be observed when the roller is moved. This sea animal takes water in a wide cavity. After that, the muscles of his body contract, pushing the liquid out through the hole that is behind. The reaction of the resulting jet allows the sibling to move forward.

Sea Missiles

But the squid, after all, has achieved the greatest perfection in jet navigation. Even the very form of the rocket seems to have been copied from this marine creature. When moving at a low speed, the squid periodically bends its diamond-shaped fin. But for a quick throw he has to use his own "jet engine". The principle of the work of all his muscles and body is worth considering in more detail.

Squids have a peculiar mantle. It is the muscle tissue that surrounds his body from all sides. During the movement, the animal sucks in this mantle a large volume of water, sharply throwing the jet through a special narrow nozzle. Such actions allow the squid to move backward at speeds of up to seventy kilometers per hour. During the movement, the animal gathers all its ten tentacles into a bundle, which gives the body a streamlined shape. There is a special valve in the nozzle. The animal turns it with the help of muscle contraction. This allows the marine dweller to change the direction of motion. The role of the helm during the movement of the squid is played by its tentacles. They direct them to the left or right, down or up, easily avoiding collisions with various obstacles.

There is a kind of squid (stenotevtis), which holds the title of the best pilot among mollusks. Describe the principle of the jet engine - and you will understand why, in pursuit of fish, this animal sometimes jumps out of the water, falling even on the decks of ships traveling across the ocean. How does this happen? The squid pilot, being in the water element, develops the maximum reactive thrust for him. This allows him to fly over the waves at a distance of up to fifty meters.

If we consider a jet engine, which animal's operating principle can be mentioned yet? This, at first glance, baggy octopus. Swimmers from them are not as fast as squid, but in case of danger their speed can be envied even by the best sprinters. Biologists who studied migrations of octopuses have found that they move like the way a jet engine operates.

The animal with each stream of water thrown out of the funnel, makes a dash for two or even two and a half meters. In this case the octopus swims in a peculiar way - backwards.

Other examples of jet propulsion

There are also rockets in the world of plants. The principle of a jet engine can be observed when, even with a very light touch, the "mad cucumber" bounces off from the stem at high speed while simultaneously tearing off the sticky liquid with the seeds. In this case, the fruit itself flies a considerable distance (up to 12 m) in the opposite direction.

The principle of the jet engine can also be observed while in the boat. If from it in the water in a certain direction to throw heavy stones, then the movement in the opposite direction will begin. The same principle holds for the rocket-propulsion system. Only there gasses are used instead of stones. They create a reactive force that ensures movement both in the air and in a depleted space.

Fantastic travel

On the flights to space, humanity has long dreamed of. This is evidenced by works of science fiction writers who, to achieve this goal, offered a variety of means. For example, the hero of the story of French writer Hercule Savinin Cyrano de Bergerac reached the Moon on an iron wagon, over which a strong magnet was constantly thrown. The famous Munchausen reached the same planet. The giant stem of the bean helped him to make the journey.

Jet propulsion was used in China in the first millennium BC. Peculiar rockets for fun at the same time served as bamboo tubes, which were filled with gunpowder. By the way, the project of the first car on our planet, created by Newton, was also with a jet engine.

History of the creation of the taxiway

Only in the 19th century. The dream of mankind about the cosmos began to acquire concrete features. It was in this century that the Russian revolutionary NI Kibalchich created the world's first project of an aircraft with a jet engine. All the papers were drawn up by the Narodnaya Volya in prison, where he got himself after the attempt on Alexander. But, unfortunately, on 03.04.1881, Kibalchich was executed, and his idea did not find a practical embodiment.

At the beginning of the 20th century. The idea of using rockets for flights into space was put forth by the Russian scientist K. E. Tsiolkovsky. For the first time his work, containing a description of the motion of a body of variable mass in the form of a mathematical equation, was published in 1903. In the future, the scientist developed the very scheme of a jet engine, propelled by liquid fuel.

Tsiolkovsky also invented a multi-stage missile and expressed the idea of creating in the near-earth orbit of these cosmic cities. Tsiolkovsky convincingly proved that the only means for space flights is a rocket. That is, an apparatus equipped with a jet engine, fueled and oxidized. Only such a missile is capable of overcoming the force of gravity and flying beyond the Earth's atmosphere.

Space exploration

The article by Tsiolkovsky, published in the periodical "Scientific Review", affirmed the reputation of the dreamer for the scientist. No one took his arguments seriously.

The idea of Tsiolkovsky was realized by Soviet scientists. Headed by Sergei Pavlovich Korolev, they launched the first artificial Earth satellite. On October 4, 1957, this vehicle delivered a rocket with a jet engine into orbit. The work of RD was based on the conversion of chemical energy, which is transferred by fuel to a gas jet, turning into kinetic energy. In this case, the rocket moves in the opposite direction.

The jet engine, the principle of operation of which has been used for many years, finds its application not only in cosmonautics, but also in aviation. But most of all it is used to launch missiles. After all, only RD is able to move the device in a space in which any medium is absent.

Liquid jet engine

Anyone who shot a firearm or just watched this process from the outside knows that there is a force that will certainly push the trunk back. And with a greater amount of charge, the return is surely increasing. The jet engine also works. The principle of its operation is similar to the way the stem is pushed backwards under the action of a jet of hot gases.

As for the rocket, in it the process, during which the mixture ignites, is gradual and continuous. This is the simplest, solid-fuel engine. He is well acquainted with all the rocket-modelists.

In a liquid propellant engine (LRE), a mixture consisting of fuel and oxidant is used to create a working fluid or a propelling jet. The latter, as a rule, is nitric acid or liquid oxygen. The fuel in the LPRE is kerosene.

The principle of operation of the jet engine, which was in the first samples, is preserved to this day. Only now it uses liquid hydrogen. In the oxidation of this substance, the specific impulse increases by 30% in comparison with the first LPRE. It is worth mentioning that the idea of using hydrogen was proposed by Tsiolkovsky himself. However, the current difficulties at work with this highly explosive substance were simply insurmountable.

What is the principle of the jet engine? Fuel and oxidizer enter the working chamber from separate tanks. Further, the components are converted into a mixture. It burns, thus releasing a colossal amount of heat under pressure in dozens of atmospheres.

Components in the working chamber of the jet engine come in different ways. Oxidizing agent is introduced here directly. But the fuel passes a longer path between the walls of the chamber and the nozzle. Here it is heated and, already having a high temperature, is thrown into the combustion zone through multiple nozzles. Further, the jet formed by the nozzle breaks out and provides the aircraft with a pusher moment. That's how you can tell what kind of jet engine the principle of operation (briefly). In this description, many components are not mentioned, without which the operation of the LPRE would not be possible. Among them, the compressors needed to create the pressure required for injection, valves, feed turbines, etc.

Modern use

Despite the fact that the work of the jet engine requires a lot of fuel, LRE continue to serve people today. They are used as the main marching engines in missile carriers, as well as shunting for various space vehicles and orbital stations. In aviation, other types of taxiways are used, which have slightly different performance characteristics and design.

Development of aviation

Since the beginning of the 20th century, until the time when the Second World War broke out, people flew only on propeller-driven aircraft. These vehicles were equipped with internal combustion engines. However, progress did not stand still. With its development, there was a need to create more powerful and fast aircraft. However, here aviation designers faced a seemingly unsolvable problem. The fact is that even with a slight increase in engine power , the mass of the aircraft increased significantly. However, the way out of the created situation was found by the Englishman Frank Will. He created a completely new engine, called a jet engine. This invention gave a powerful impetus to the development of aviation.

The principle of operation of a jet engine of an aircraft is similar to that of a fire hose. Its hose has a narrowed end. Leaving through a narrow hole, water greatly increases its speed. The resulting back pressure force is so strong that the fireman can hardly hold the hose in his hands. This behavior of water can also explain the principle of the jet engine's operation.

Straight-flow taxiways

This type of jet engine is the simplest. Represent it can be in the form of a pipe with open ends, which is installed on a moving airplane. At the front, its cross-section widens. Due to this design, incoming air reduces its speed and its pressure increases. The widest place of such a pipe is the combustion chamber. Here, the fuel is injected and its combustion is continued. Such a process promotes the heating of the gases formed and their strong expansion. This creates the thrust of the jet engine. It produces all the same gases when they force outward from the narrow end of the pipe. It is this pull that forces the plane to fly.

Problems of use

Straight-flow jet engines have some disadvantages. They are able to work only on that plane, which is in motion. The aircraft, which is in a state of rest, can not be activated by direct-action taxiways. In order to lift such an airplane, any other starting engine is needed.

Solution

The principle of operation of the jet engine of the turbojet type aircraft, which lacks the shortcomings of the ramjet, allowed the aircraft designers to create the most perfect aircraft. How does this invention work?

The main element in the turbojet engine is a gas turbine. With its help, an air compressor is activated, passing through which compressed air is directed to a special chamber. The resulting fuel combustion (usually kerosene) products fall on the turbine blades, than it drives it. Further, the air-gas flow passes into the nozzle, where it accelerates to high velocities and creates a tremendous reactive traction force.

Power increase

The reactive traction force can increase significantly over a short period of time. For this purpose, afterburning is used. It is the injection of an additional amount of fuel into the gas stream that escapes from the turbine. Unused in the turbine, oxygen contributes to the combustion of kerosene, which increases the thrust of the engine. At high speeds, the increase in its value reaches 70%, and at small speeds it reaches 25-30%.

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