Under the jet movement is understood, in which one of its parts is separated from the body at a certain speed. The resulting force acts on its own. In other words, she lacks even the slightest contact with external bodies.
Jet propulsion in nature
During a summer vacation in the south, almost every one of us, swimming in the sea, met with jellyfish. But few people thought about the fact that these animals move in the same way as a jet engine. The principle of operation in nature of such an aggregate can be observed when moving some types of marine plankton and dragonfly larvae. Moreover, the efficiency of these invertebrates is often higher than that of technical means.
Who else can demonstrate how a jet engine works? Squid, octopus and cuttlefish. A similar movement is made by many other marine mollusks. Take, for example, cuttlefish. She draws water into her gill cavity and throws it vigorously through a funnel, which she directs back or sideways. Whereinthe mollusk is able to move in the right direction.
The principle of operation of a jet engine can also be observed when moving the lard. This marine animal takes in water into a wide cavity. After that, the muscles of his body contract, pushing the liquid out through the hole in the back. The reaction of the resulting jet allows the tallow to move forward.
Sea missiles
But squids have achieved the greatest perfection in jet navigation. Even the shape of the rocket itself seems to be copied from this particular marine life. When moving at 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 operation of all his muscles and body is worth considering in more detail.
Squid have a peculiar mantle. This is the muscle tissue that surrounds his body from all sides. During movement, the animal sucks a large volume of water into this mantle, sharply ejecting a jet through a special narrow nozzle. Such actions allow squids to move in jerks backwards at speeds up to seventy kilometers per hour. During movement, the animal gathers all its ten tentacles into a bundle, which gives the body a streamlined shape. The nozzle has a special valve. The animal turns it with the help of muscle contraction. This allows the marine life to change direction. The role of the steering wheel during the movements of the squid is also played by its tentacles. He directs them to the left or right, downor up, easily dodging collisions with various obstacles.
There is a species of squid (stenoteuthys), which holds the title of the best pilot among shellfish. Describe the principle of operation of a jet engine - and you will understand why, chasing fish, this animal sometimes jumps out of the water, even getting on the decks of ships sailing across the ocean. How does it happen? Pilot squid, being in the water element, develops maximum jet 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, the principle of operation of which animal can be mentioned more? These are, at first glance, baggy octopuses. Their swimmers are not as fast as squids, but in case of danger even the best sprinters can envy their speed. Biologists who have studied octopus migrations have found that they move like a jet engine works.
The animal with each jet of water thrown out of the funnel makes a jerk of two or even two and a half meters. At the same time, the octopus swims in a peculiar way - backwards.
Other examples of jet propulsion
There are rockets in the world of plants. The principle of a jet engine can be observed when, even with a very light touch, the “crazy cucumber” bounces off the stalk at high speed, while simultaneously rejecting the sticky liquid with seeds. At the same time, the fetus itself flies a considerable distance (up to 12 m) in the opposite direction.
The principle of the jet engine can also be observed,while on the boat. If heavy stones are thrown from it into the water in a certain direction, then movement will begin in the opposite direction. The principle of operation of a rocket jet engine is the same. Only there gases are used instead of stones. They create a reactive force that provides movement both in the air and in rarefied space.
Fantastic Journeys
Mankind has long dreamed of flying into space. This is evidenced by the works of science fiction writers, who offered a variety of means to achieve this goal. For example, the hero of the story of the French writer Hercule Savignin, Cyrano de Bergerac, reached the moon on an iron cart, over which a strong magnet was constantly thrown up. The famous Munchausen also reached the same planet. A giant bean stalk helped him make the journey.
Jet propulsion was used in China as early as the first millennium BC. At the same time, bamboo tubes, which were filled with gunpowder, served as a kind of rockets for fun. 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 RD
Only in the 19th c. Mankind's dream of outer space began to acquire concrete features. After all, it was in this century that the Russian revolutionary N. I. Kibalchich created the world's first project of an aircraft with a jet engine. All the papers were drawn up by a Narodnaya Volya in prison, where he ended up after the assassination attempt on Alexander. But, unfortunately, on 1881-03-04Kibalchich was executed, and his idea did not find practical implementation.
At the beginning of the 20th c. the idea of using rockets for flights into space was put forward by the Russian scientist K. E. Tsiolkovsky. For the first time, his work, containing a description of the movement of a body of variable mass in the form of a mathematical equation, was published in 1903. Later, the scientist developed the very scheme of a jet engine driven by liquid fuel.
Also, Tsiolkovsky invented a multi-stage rocket and put forward the idea of creating real space cities in near-Earth orbit. Tsiolkovsky convincingly proved that the only means for space flight is a rocket. That is, an apparatus equipped with a jet engine, refueled with fuel and an oxidizer. Only such a rocket is capable of overcoming gravity and flying beyond the Earth's atmosphere.
Space exploration
An article by Tsiolkovsky, published in the periodical "Scientific Review", established the scientist's reputation as a dreamer. Nobody took his arguments seriously.
Tsiolkovsky's idea was implemented by Soviet scientists. Headed by Sergei Pavlovich Korolev, they launched the first artificial Earth satellite. On October 4, 1957, this apparatus was delivered into orbit by a rocket with a jet engine. The work of the RD was based on the conversion of chemical energy, which is transferred by the fuel to the gas jet, turning into kinetic energy. In this case, the rocket moves in the opposite direction.direction.
The jet engine, the principle of which has been used for many years, finds its application not only in astronautics, but also in aviation. But most of all it is used to launch rockets. After all, only the RD is able to move the device in a space in which there is no medium.
Liquid Jet Engine
Those who have fired a firearm or simply watched this process from the side know that there is a force that will certainly push the barrel back. Moreover, with a larger amount of charge, the return will certainly increase. The jet engine works the same way. Its principle of operation is similar to how the barrel is pushed back under the action of a jet of hot gases.
As for the rocket, the process during which the mixture is ignited is gradual and continuous. This is the simplest, solid fuel engine. He is well known to all rocket modellers.
In a liquid-propellant jet engine (LRE), a mixture consisting of fuel and oxidizer is used to create a working fluid or a pushing jet. The last, as a rule, is nitric acid or liquid oxygen. The fuel in the LRE is kerosene.
The principle of operation of the jet engine, which was in the first samples, has been preserved to this day. Only now it uses liquid hydrogen. When this substance is oxidized, the specific impulse increases by 30% in comparison with the first liquid-propellant rocket engines. It is worth saying that the idea of using hydrogen wasproposed by Tsiolkovsky himself. However, the difficulties of working with this extremely explosive substance at that time were simply insurmountable.
What is the working principle of a jet engine? Fuel and oxidizer enter the working chamber from separate tanks. Next, the components are converted into a mixture. It burns, releasing an enormous amount of heat under pressure of tens of atmospheres.
Components enter the working chamber of a jet engine in different ways. The oxidizing agent is introduced here directly. But the fuel travels 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 numerous nozzles. Further, the jet formed by the nozzle breaks out and provides the aircraft with a pushing moment. This is how you can tell what a jet engine has the principle of operation (briefly). This description does not mention many components, without which the operation of the LRE would be impossible. Among them are the compressors needed to create the pressure required for injection, valves, supply turbines, etc.
Modern usage
Despite the fact that the operation of a jet engine requires a large amount of fuel, rocket engines continue to serve people today. They are used as the main propulsion engines in launch vehicles, as well as shunting engines for various spacecraft and orbital stations. In aviation, other types of taxiways are used, which have slightly different performance characteristics anddesign.
Development of aviation
From the early 20th century until the outbreak of World War II, people flew only in propeller-driven aircraft. These devices were equipped with internal combustion engines. However, progress did not stand still. With its development, there was a need to create more powerful and faster aircraft. However, here aircraft designers are faced with a seemingly insoluble 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 fundamentally new engine, called jet. This invention gave a powerful impetus to the development of aviation.
The principle of operation of an aircraft jet engine is similar to the actions of a fire hose. Its hose has a tapered end. Flowing out through a narrow opening, water significantly increases its speed. The back pressure force created in this case is so strong that the firefighter can hardly hold the hose in his hands. This behavior of water can also explain the principle of operation of an aircraft jet engine.
Directional taxiways
This type of jet engine is the simplest. You can imagine it in the form of a pipe with open ends, which is installed on a moving plane. In front of its cross section expands. Due to this design, the incoming air reduces its speed, and its pressure increases. The widest point of such a pipeis the combustion chamber. This is where the fuel is injected and then burned. Such a process contributes to the heating of the formed gases and their strong expansion. This creates the thrust of a jet engine. It is produced by all the same gases when they burst out with force from the narrow end of the pipe. It is this thrust that makes the plane fly.
Problems of use
Sramjet engines have some drawbacks. They are able to work only on the aircraft that is in motion. An aircraft at rest cannot be activated by direct-flow taxiways. In order to lift such an aircraft into the air, any other starting engine is needed.
Problem Solving
The principle of operation of a jet engine of a turbojet type aircraft, which is devoid of the shortcomings of a direct-flow taxiway, allowed aircraft designers to create the most advanced aircraft. How does this invention work?
The main element in a turbojet engine is a gas turbine. With its help, an air compressor is driven, passing through which the compressed air is directed to a special chamber. The products obtained as a result of the combustion of fuel (usually kerosene) fall on the blades of the turbine, which drives it. Further, the air-gas flow passes into the nozzle, where it accelerates to high speeds and creates a huge jet thrust.
Power increase
Reactive thrust force canincrease significantly in a short period of time. For this, afterburning is used. It is the injection of additional fuel into the gas stream escaping from the turbine. Unused oxygen in the turbine contributes to the combustion of kerosene, which increases the engine thrust. At high speeds, the increase in its value reaches 70%, and at low speeds - 25-30%.
