How does an airplane jet engine work? Jet engine operation diagram

A jet engine is an engine that creates the traction force necessary for movement by converting the internal energy of the fuel into the kinetic energy of the jet stream of the working fluid.

The working fluid flows out of the engine at high speed, and, in accordance with the law of conservation of momentum, a reactive force is generated, pushing the engine in the opposite direction. To accelerate the working fluid, both the expansion of gas heated in one way or another to a high thermal temperature (the so-called thermal jet engines) and other physical principles, for example, the acceleration of charged particles in an electrostatic field (see ion engine).

A jet engine combines the engine itself with a propulsion device, that is, it creates traction force only through interaction with the working fluid, without support or contact with other bodies. For this reason, it is most often used to propel aircraft, rockets and spacecraft.

In a jet engine, the thrust required for propulsion is created by converting the initial energy into the kinetic energy of the working fluid. As a result of the outflow of the working fluid from the engine nozzle, a reactive force is generated in the form of recoil (jet). The recoil moves the engine and the apparatus structurally connected to it in space. The movement occurs in the direction opposite to the outflow of the jet. Can be converted into kinetic energy of the jet stream different kinds energies: chemical, nuclear, electrical, solar. A jet engine provides its own propulsion without the participation of intermediate mechanisms.

To create jet thrust, you need a source of initial energy, which is converted into the kinetic energy of the jet stream, a working fluid ejected from the engine in the form of a jet stream, and the jet engine, converting the first type of energy into the second.

The main part of a jet engine is the combustion chamber, in which the working fluid is created.

All jet engines are divided into two main classes, depending on whether they operate using the environment or not.

The first class is air-breathing engines (WRE). All of them are thermal, in which the working fluid is formed during the oxidation reaction of a flammable substance with oxygen from the surrounding air. The main mass of the working fluid is atmospheric air.

In a rocket engine, all components of the working fluid are located on board the apparatus equipped with it.

There are also combined engines that combine both of the above types.

Jet propulsion was first used in Heron's ball, a prototype of a steam turbine. Solid fuel jet engines appeared in China in the 10th century. n. e. Such missiles were used in the East, and then in Europe for fireworks, signaling, and then as combat missiles.

An important stage in the development of the idea of ​​jet propulsion was the idea of ​​​​using a rocket as an engine for an aircraft. It was first formulated by the Russian revolutionary N.I. Kibalchich, who in March 1881, shortly before his execution, proposed a design for an aircraft (rocket plane) using jet propulsion from explosive powder gases.

N. E. Zhukovsky, in his works “On the reaction of outflowing and inflowing liquids” (1880s) and “On the theory of ships driven by the reaction force of outflowing water” (1908), first developed the basic issues of the theory of a jet engine.

Interesting works on the study of rocket flight also belong to the famous Russian scientist I.V. Meshchersky, in particular in the field general theory body movements variable mass.

In 1903, K. E. Tsiolkovsky, in his work “Exploration of world spaces using jet instruments,” gave a theoretical justification for the flight of a rocket, as well as schematic diagram rocket engine, which anticipated many fundamental and design features modern liquid rocket engines (LPRE). Thus, Tsiolkovsky envisaged the use of liquid fuel for a jet engine and its supply to the engine with special pumps. He proposed to control the flight of the rocket using gas rudders - special plates placed in a stream of gases escaping from the nozzle.

The peculiarity of a liquid jet engine is that, unlike other jet engines, it carries with it the entire supply of oxidizer along with the fuel, and does not take the air containing oxygen necessary for burning the fuel from the atmosphere. This is the only engine that can be used for ultra-high-altitude flight outside the earth's atmosphere.

The world's first rocket with a liquid rocket engine was created and launched on March 16, 1926 by the American R. Goddard. It weighed about 5 kilograms, and its length reached 3 m. The fuel in Goddard’s rocket was gasoline and liquid oxygen. The flight of this rocket lasted 2.5 seconds, during which it flew 56 m.

Systematic experimental work on these engines began in the 30s of the 20th century.

The first Soviet liquid-propellant rocket engines were developed and created in 1930–1931. at the Leningrad Gas Dynamic Laboratory (GDL) under the leadership of the future academician V. P. Glushko. This series was called ORM - experimental rocket motor. Glushko used some new innovations, for example, cooling the engine with one of the fuel components.

In parallel, the development of rocket engines was carried out in Moscow by the Jet Propulsion Research Group (GIRD). Her ideological inspirer was F.A. Tsander, and the organizer was the young S.P. Korolev. Korolev's goal was to build a new rocket vehicle - a rocket plane.

In 1933, F.A. Zander built and successfully tested the OR1 rocket engine, which ran on gasoline and compressed air, and in 1932–1933. – OR2 engine, running on gasoline and liquid oxygen. This engine was designed to be installed on a glider that was intended to fly as a rocket plane.

In 1933, the first Soviet rocket was created and tested at GIRD liquid fuel.

Developing the work they had begun, Soviet engineers subsequently continued to work on the creation of liquid jet engines. In total, from 1932 to 1941, the USSR developed 118 designs of liquid jet engines.

In Germany in 1931, tests of missiles by I. Winkler, Riedel and others took place.

The first flight of a rocket plane with a liquid-propellant engine was made in the Soviet Union in February 1940. A liquid-propellant rocket engine was used as the aircraft's power plant. In 1941, under the leadership of the Soviet designer V.F. Bolkhovitinov, the first jet aircraft was built - a fighter with a liquid-propellant rocket engine. Its tests were carried out in May 1942 by pilot G. Ya. Bakhchivadzhi.

At the same time, the first flight of a German fighter with such an engine took place. In 1943, the United States tested the first American jet aircraft equipped with a liquid-propellant jet engine. In Germany, several fighters with these Messerschmitt-designed engines were built in 1944 and used in combat on the Western Front that same year.

In addition, liquid rocket engines were used on German V2 rockets, created under the leadership of V. von Braun.

In the 1950s, liquid-propellant engines were installed on ballistic missiles, and then on artificial satellites of the Earth, Sun, Moon and Mars, and automatic interplanetary stations.

The liquid-propellant rocket engine consists of a combustion chamber with a nozzle, a turbopump unit, a gas generator or steam-gas generator, an automation system, control elements, an ignition system and auxiliary units (heat exchangers, mixers, drives).

The idea of ​​air-breathing engines has been put forward more than once in different countries. The most important and original works in this regard are the studies carried out in 1908–1913. French scientist R. Lauren, who, in particular, in 1911 proposed a number of designs for ramjet engines. These engines use atmospheric air as an oxidizer, and air compression in the combustion chamber is ensured by dynamic air pressure.

In May 1939, a rocket with a ramjet engine designed by P. A. Merkulov was tested for the first time in the USSR. It was a two-stage rocket (the first stage is a powder rocket) with a take-off weight of 7.07 kg, and the weight of the fuel for the second stage of the ramjet engine was only 2 kg. During testing, the rocket reached an altitude of 2 km.

In 1939–1940 For the first time in the world, summer tests of air-breathing engines installed as additional engines on an aircraft designed by N.P. Polikarpov were carried out in the Soviet Union. In 1942, ramjet engines designed by E. Zenger were tested in Germany.

An air-breathing engine consists of a diffuser in which air is compressed due to the kinetic energy of the oncoming air flow. Fuel is injected into the combustion chamber through a nozzle and the mixture ignites. The jet stream exits through the nozzle.

The process of operation of the jet engines is continuous, so they do not have starting thrust. In this regard, at flight speeds less than half the speed of sound, air-breathing engines are not used. The most effective use of jet engines is at supersonic speeds and high altitudes. An aircraft powered by a jet engine takes off using rocket engines running on solid or liquid fuel.

Another group of air-breathing engines – turbocompressor engines – has received greater development. They are divided into turbojet, in which the thrust is created by a stream of gases flowing from the jet nozzle, and turboprop, in which the main thrust is created by the propeller.

In 1909, the design of a turbojet engine was developed by engineer N. Gerasimov. In 1914, Russian lieutenant navy M. N. Nikolskoy designed and built a model of a turboprop aircraft engine. The working fluid for driving the three-stage turbine was the gaseous combustion products of a mixture of turpentine and nitric acid. The turbine worked not only on the propeller: the exhaust gaseous combustion products directed into the tail (jet) nozzle created jet thrust in addition to the thrust force of the propeller.

In 1924, V.I. Bazarov developed the design of an aviation turbocompressor jet engine, which consisted of three elements: a combustion chamber, a gas turbine, and a compressor. The flow of compressed air here was for the first time divided into two branches: the smaller part went into the combustion chamber (to the burner), and the larger part was mixed with the working gases to lower their temperature in front of the turbine. This ensured the safety of the turbine blades. The power of the multistage turbine was spent on driving the centrifugal compressor of the engine itself and partly on rotating the propeller. In addition to the propeller, thrust was created due to the reaction of a stream of gases passed through the tail nozzle.

In 1939, the construction of turbojet engines designed by A. M. Lyulka began at the Kirov plant in Leningrad. His trials were interrupted by the war.

In 1941, in England, the first flight was carried out on an experimental fighter aircraft equipped with a turbojet engine designed by F. Whittle. It was equipped with an engine with a gas turbine, which drove a centrifugal compressor that supplied air to the combustion chamber. Combustion products were used to create jet thrust.

Whittle's Gloster (E.28/39)

In a turbojet engine, the air entering during flight is compressed first in the air intake and then in the turbocharger. Compressed air is supplied to the combustion chamber, into which liquid fuel (most often aviation kerosene) is injected. Partial expansion of the gases formed during combustion occurs in the turbine rotating the compressor, and the final expansion occurs in the jet nozzle. An afterburner chamber can be installed between the turbine and the jet engine, designed to additional combustion fuel.

Nowadays, most military and civil aircraft, as well as some helicopters, are equipped with turbojet engines.

In a turboprop engine, the main thrust is generated by the propeller, and additional thrust (about 10%) is generated by a stream of gases flowing from the jet nozzle. The principle of operation of a turboprop engine is similar to a turbojet, with the difference that the turbine rotates not only the compressor, but also the propeller. These engines are used in subsonic aircraft and helicopters, as well as for the propulsion of high-speed ships and cars.

The earliest solid propellant jet engines were used in combat missiles. Their wide application began in the 19th century, when missile units appeared in many armies. IN late XIX V. the first ones were created smokeless powders, with more stable combustion and greater efficiency.

In the 1920s–1930s, work was carried out to create rocket weapons. This led to the emergence rocket launchers- "Katyusha" in the Soviet Union, six-barreled rocket mortars in Germany.

The development of new types of gunpowder has made it possible to use solid-fuel jet engines in combat missiles, including ballistic ones. In addition, they are used in aviation and astronautics as engines for the first stages of rocket launch vehicles, starting engines for aircraft with ramjet engines, and braking engines for spacecraft.

A solid fuel jet engine consists of a housing (combustion chamber), which contains the entire fuel supply and a jet nozzle. The body is made of steel or fiberglass. Nozzle - made of graphite, refractory alloys, graphite.

The fuel is ignited by an ignition device.

Thrust control is carried out by changing the combustion surface of the charge or the critical cross-sectional area of ​​the nozzle, as well as by injecting liquid into the combustion chamber.

The direction of thrust can be changed by gas rudders, a deflector (deflector), auxiliary control motors, etc.

Solid fuel jet engines are very reliable, can be stored for a long time, and therefore are always ready to start.

In a jet engine, the thrust required for propulsion is created by converting the initial energy into the kinetic energy of the working fluid. As a result of the outflow of the working fluid from the engine nozzle, a reactive force is generated in the form of recoil (jet). The recoil moves the engine and the apparatus structurally connected to it in space. The movement occurs in the direction opposite to the outflow of the jet. Various types of energy can be converted into the kinetic energy of a jet stream: chemical, nuclear, electrical, solar. A jet engine provides its own propulsion without the participation of intermediate mechanisms.

To create jet thrust, you need a source of initial energy, which is converted into the kinetic energy of the jet stream, a working fluid ejected from the engine in the form of a jet stream, and the jet engine itself, which converts the first type of energy into the second.

The main part of a jet engine is the combustion chamber, in which the working fluid is created.

All jet engines are divided into two main classes, depending on whether they operate using the environment or not.

The first class is air-jet engines (WRD). All of them are thermal, in which the working fluid is formed during the oxidation reaction of a flammable substance with oxygen from the surrounding air. The bulk of the working fluid is atmospheric air.

In a rocket engine, all components of the working fluid are located on board the apparatus equipped with it.

There are also combined engines that combine both of the above types.

Jet propulsion was first used in Heron's ball, a prototype of a steam turbine. Solid fuel jet engines appeared in China in the 10th century. n. e. Such missiles were used in the East, and then in Europe for fireworks, signaling, and then as combat missiles.

An important stage in the development of the idea of ​​jet propulsion was the idea of ​​​​using a rocket as an engine for an aircraft. It was first formulated by the Russian revolutionary N.I. Kibalchich, who in March 1881, shortly before his execution, proposed a design for an aircraft (rocket plane) using jet propulsion from explosive powder gases.

N. E. Zhukovsky, in his works “On the reaction of outflowing and inflowing liquid” (1880s) and “On the theory of ships driven by the reaction force of outflowing water” (1908), first developed the basic issues of the theory of a jet engine.

Interesting works on the study of rocket flight also belong to the famous Russian scientist I.V. Meshchersky, in particular in the field of the general theory of motion of bodies of variable mass.

In 1903, K. E. Tsiolkovsky, in his work “Exploration of World Spaces with Jet Instruments,” gave a theoretical justification for the flight of a rocket, as well as a schematic diagram of a rocket engine, which anticipated many of the fundamental and design features of modern liquid-propellant rocket engines (LPRE). Thus, Tsiolkovsky envisaged the use of liquid fuel for a jet engine and its supply to the engine with special pumps. He proposed to control the flight of the rocket using gas rudders - special plates placed in a stream of gases escaping from the nozzle.

The peculiarity of a liquid-propellant jet engine is that, unlike other jet engines, it carries with it the entire supply of oxidizer along with the fuel, and does not take the air containing oxygen necessary for burning the fuel from the atmosphere. This is the only engine that can be used for ultra-high-altitude flight outside the earth's atmosphere.

The world's first rocket with a liquid rocket engine was created and launched on March 16, 1926 by the American R. Goddard. It weighed about 5 kilograms, and its length reached 3 m. The fuel in Goddard’s rocket was gasoline and liquid oxygen. The flight of this rocket lasted 2.5 seconds, during which it flew 56 m.

Systematic experimental work on these engines began in the 30s of the 20th century.

The first Soviet liquid-propellant rocket engines were developed and created in 1930–1931. at the Leningrad Gas Dynamic Laboratory (GDL) under the leadership of the future academician V. P. Glushko. This series was called ORM - experimental rocket motor. Glushko used some new innovations, for example, cooling the engine with one of the fuel components.

In parallel, the development of rocket engines was carried out in Moscow by the Jet Propulsion Research Group (GIRD). Its ideological inspirer was F.A. Tsander, and its organizer was the young S.P. Korolev. Korolev's goal was to build a new rocket vehicle - a rocket plane.

In 1933, F.A. Zander built and successfully tested the OR-1 rocket engine, running on gasoline and compressed air, and in 1932–1933. – OR?2 engine, running on gasoline and liquid oxygen. This engine was designed to be installed on a glider that was intended to fly as a rocket plane.

In 1933, the first Soviet liquid-fuel rocket was created and tested at GIRD.

Developing the work they had begun, Soviet engineers subsequently continued to work on the creation of liquid jet engines. In total, from 1932 to 1941, the USSR developed 118 designs of liquid jet engines.

In Germany in 1931, tests of missiles by I. Winkler, Riedel and others took place.

The first flight of an airplane/rocket plane with a liquid-propellant jet engine was made in the Soviet Union in February 1940. A liquid-propellant rocket engine was used as the aircraft's power plant. In 1941, under the leadership of the Soviet designer V.F. Bolkhovitinov, the first jet aircraft was built - a fighter with a liquid-propellant rocket engine. Its tests were carried out in May 1942 by pilot G. Ya. Bakhchivadzhi.

At the same time, the first flight of a German fighter with such an engine took place. In 1943, the United States tested the first American jet aircraft, which was equipped with a liquid-propellant jet engine. In Germany, several fighters with these Messerschmitt-designed engines were built in 1944 and used in combat on the Western Front that same year.

In addition, liquid-propellant rocket engines were used on German V-2 rockets, created under the leadership of V. von Braun.

In the 1950s, liquid-propellant rocket engines were installed on ballistic missiles, and then on artificial satellites of the Earth, Sun, Moon and Mars, automatic interplanetary stations.

The liquid-propellant rocket engine consists of a combustion chamber with a nozzle, a turbopump unit, a gas generator or steam-gas generator, an automation system, control elements, an ignition system and auxiliary units (heat exchangers, mixers, drives).

The idea of ​​air-jet engines has been put forward more than once in different countries. The most important and original works in this regard are the studies carried out in 1908–1913. French scientist R. Lauren, who, in particular, in 1911 proposed a number of designs for ramjet engines. These engines use atmospheric air as an oxidizer, and air compression in the combustion chamber is ensured by dynamic air pressure.

In May 1939, a rocket with a ramjet engine designed by P. A. Merkulov was tested for the first time in the USSR. It was a two-stage rocket (the first stage is a powder rocket) with a take-off weight of 7.07 kg, and the weight of the fuel for the second stage of the ramjet engine was only 2 kg. During testing, the rocket reached an altitude of 2 km.

In 1939–1940 For the first time in the world, summer tests of air-breathing engines installed as additional engines on an aircraft designed by N.P. Polikarpov were carried out in the Soviet Union. In 1942, ramjet engines designed by E. Zenger were tested in Germany.

An air-jet engine consists of a diffuser in which air is compressed due to the kinetic energy of the oncoming air flow. Fuel is injected into the combustion chamber through a nozzle and the mixture ignites. The jet stream exits through the nozzle.

The process of operation of the jet engines is continuous, so they do not have starting thrust. In this regard, at flight speeds less than half the speed of sound, air-jet engines are not used. The most effective use of jet engines is at supersonic speeds and high altitudes. An aircraft powered by an air-jet engine takes off using rocket engines running on solid or liquid fuel.

Another group of air-jet engines – turbocompressor engines – has received greater development. They are divided into turbojet, in which the thrust is created by a stream of gases flowing from the jet nozzle, and turboprop, in which the main thrust is created by the propeller.

In 1909, the design of a turbojet engine was developed by engineer N. Gerasimov. In 1914, Lieutenant of the Russian Navy M.N. Nikolskoy designed and built a model of a turboprop aircraft engine. The working fluid for driving the three-stage turbine was the gaseous combustion products of a mixture of turpentine and nitric acid. The turbine worked not only on the propeller: the exhaust gaseous combustion products directed into the tail (jet) nozzle created jet thrust in addition to the thrust force of the propeller.

In 1924, V.I. Bazarov developed the design of an aviation turbocompressor jet engine, which consisted of three elements: a combustion chamber, a gas turbine, and a compressor. The flow of compressed air here was for the first time divided into two branches: the smaller part went into the combustion chamber (to the burner), and the larger part was mixed with the working gases to lower their temperature in front of the turbine. This ensured the safety of the turbine blades. The power of the multistage turbine was spent on driving the centrifugal compressor of the engine itself and partly on rotating the propeller. In addition to the propeller, thrust was created due to the reaction of a stream of gases passed through the tail nozzle.

In 1939, the construction of turbojet engines designed by A. M. Lyulka began at the Kirov plant in Leningrad. His trials were interrupted by the war.

In 1941, in England, the first flight was carried out on an experimental fighter aircraft equipped with a turbojet engine designed by F. Whittle. It was equipped with an engine with a gas turbine, which drove a centrifugal compressor that supplied air to the combustion chamber. Combustion products were used to create jet thrust.

In a turbojet engine, the air entering during flight is compressed first in the air intake and then in the turbocharger. Compressed air is supplied to the combustion chamber, into which liquid fuel (most often aviation kerosene) is injected. Partial expansion of the gases formed during combustion occurs in the turbine rotating the compressor, and the final expansion occurs in the jet nozzle. An afterburner can be installed between the turbine and the jet engine to provide additional fuel combustion.

Nowadays, most military and civil aircraft, as well as some helicopters, are equipped with turbojet engines.

In a turboprop engine, the main thrust is generated by the propeller, and additional thrust (about 10%) is generated by a stream of gases flowing from the jet nozzle. The principle of operation of a turboprop engine is similar to a turbojet, with the difference that the turbine rotates not only the compressor, but also the propeller. These engines are used in subsonic aircraft and helicopters, as well as for the propulsion of high-speed ships and cars.

The earliest solid propellant jet engines were used in combat missiles. Their widespread use began in the 19th century, when missile units appeared in many armies. At the end of the 19th century. The first smokeless powders were created, with more stable combustion and greater performance.

In the 1920–1930s, work was carried out to create jet weapons. This led to the emergence of rocket-propelled mortars - Katyushas in the Soviet Union, six-barreled rocket-propelled mortars in Germany.

The development of new types of gunpowder has made it possible to use solid-fuel jet engines in combat missiles, including ballistic ones. In addition, they are used in aviation and astronautics as engines for the first stages of launch vehicles, starting engines for aircraft with ramjet engines, and braking engines for spacecraft.

A solid fuel jet engine consists of a housing (combustion chamber), which contains the entire fuel supply and a jet nozzle. The body is made of steel or fiberglass. Nozzle - made of graphite, refractory alloys, graphite.

The fuel is ignited by an ignition device.

Thrust control is carried out by changing the combustion surface of the charge or the critical cross-sectional area of ​​the nozzle, as well as by injecting liquid into the combustion chamber.

The direction of thrust can be changed by gas rudders, a deflector (deflector), auxiliary control motors, etc.

Solid fuel jet engines are very reliable, can be stored for a long time, and therefore are always ready to start.

Excellent definition

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ABSTRACT

ON THIS TOPIC:

Jet Engines .

WRITTEN BY: Kiselev A.V.

KALININGRAD

Introduction

Jet engine, an engine that creates the traction force necessary for movement by converting the initial energy into the kinetic energy of the jet stream of the working fluid; As a result of the outflow of the working fluid from the engine nozzle, a reactive force is generated in the form of a reaction (recoil) of the jet, moving the engine and the apparatus structurally connected to it in space in the direction opposite to the outflow of the jet. Various types of energy (chemical, nuclear, electrical, solar) can be converted into the kinetic (velocity) energy of a jet stream in a rocket jet. A direct reaction engine (direct reaction engine) combines the engine itself with a propulsion device, i.e., it provides its own movement without the participation of intermediate mechanisms.

To create the jet thrust used by R.D., it is necessary:

source of initial (primary) energy, which is converted into kinetic energy of the jet stream;

the working fluid, which is ejected from the jet in the form of a jet stream;

The R.D. itself is an energy converter.

The initial energy is stored on board an aircraft or other vehicle equipped with a rocket engine (chemical fuel, nuclear fuel), or (in principle) can come from outside (solar energy). To obtain a working fluid in a liquid propellant, a substance taken from the environment (for example, air or water) can be used;

a substance located in the tanks of the apparatus or directly in the R.D. chamber; a mixture of substances coming from the environment and stored on board the vehicle.

In modern R.D., chemical is most often used as a primary

Missile fire tests

engine Space Shuttle

Turbojet engines AL-31F airplane Su-30MK. Belong to class air-breathing engines

energy. In this case, the working fluid is hot gases - products of combustion of chemical fuels. During the operation of a combustion engine, the chemical energy of combustion substances is converted into thermal energy of combustion products, and thermal energy hot gases are converted into mechanical energy of the translational motion of the jet stream and, consequently, the apparatus on which the engine is installed. The main part of any combustion engine is the combustion chamber in which the working fluid is generated. The final part of the chamber, which serves to accelerate the working fluid and produce a jet stream, is called a jet nozzle.

Depending on whether or not the environment is used during the operation of rocket engines, they are divided into 2 main classes - air-breathing engines (ARE) and rocket engines (RE). All VRDs are heat engines, the working fluid of which is formed during the oxidation reaction of a combustible substance with atmospheric oxygen. The air coming from the atmosphere makes up the bulk of the working fluid of the WRD. Thus, a device with a propellant engine carries an energy source (fuel) on board, and draws most of the working fluid from the environment. In contrast to the VRD, all components of the working fluid of the thruster are located on board the apparatus equipped with the thruster. Lack of propulsion that interacts with environment, and the presence of all components of the working fluid on board the device make the RD the only one suitable for work in space. There are also combined rocket engines, which are a combination of both main types.

History of jet engines

The principle of jet propulsion has been known for a very long time. The ancestor of R. d. can be considered the ball of Heron. Solid propellant rocket engines - powder rockets - appeared in China in the 10th century. n. e. For hundreds of years, such missiles were used first in the East and then in Europe as fireworks, signal, and combat missiles. In 1903, K. E. Tsiolkovsky, in his work “Exploration of World Spaces with Jet Instruments,” was the first in the world to put forward the basic principles of the theory of liquid rocket engines and proposed the basic elements of a liquid-fuel rocket engine design. The first Soviet liquid rocket engines - ORM, ORM-1, ORM-2 were designed by V.P. Glushko and, under his leadership, created in 1930-31 at the Gas Dynamics Laboratory (GDL). In 1926, R. Goddard launched a rocket using liquid fuel. The first electrothermal RD was created and tested by Glushko at the GDL in 1929-33.

In 1939, the USSR tested missiles with ramjet engines designed by I. A. Merkulov. The first turbojet engine diagram? was proposed by the Russian engineer N. Gerasimov in 1909.

In 1939, the construction of turbojet engines designed by A. M. Lyulka began at the Kirov plant in Leningrad. The testing of the created engine was prevented by the Great Patriotic War of 1941-45. In 1941, a turbojet engine designed by F. Whittle (Great Britain) was first installed on an aircraft and tested. Great importance The creation of R.D. was based on the theoretical works of Russian scientists S. S. Nezhdanovsky, I. V. Meshchersky, N. E. Zhukovsky, the works of the French scientist R. Hainault-Peltry, and the German scientist G. Oberth. An important contribution to the creation of the WRD was the work of the Soviet scientist B. S. Stechkin, “The Theory of an Air-Jet Engine,” published in 1929.

R.D. have various purposes and the scope of their application is constantly expanding.

Radar drives are most widely used on aircraft of various types.

Most military and civil aircraft around the world are equipped with turbojet engines and bypass turbojet engines, and they are used on helicopters. These radar engines are suitable for flights at both subsonic and supersonic speeds; They are also installed on projectile aircraft; supersonic turbojet engines can be used in the first stages of aerospace aircraft. Ramjet engines are installed on anti-aircraft guided missiles, cruise missiles, and supersonic interceptor fighters. Subsonic ramjet engines are used on helicopters (installed at the ends of the main rotor blades). Pulse jet engines have low thrust and are intended only for aircraft at subsonic speeds. During the 2nd World War 1939-45, these engines were equipped with V-1 projectile aircraft.

Taxiways are mostly used on high-speed aircraft.

Liquid rocket engines are used on launch vehicles of spacecraft and spacecraft as propulsion, braking and control engines, as well as on guided ballistic missiles. Solid propellant rocket engines are used in ballistic, anti-aircraft, anti-tank and other military missiles, as well as on launch vehicles and spacecraft. Small solid propellant engines are used as boosters for aircraft take-off. Electric rocket motors and nuclear rocket motors can be used on spacecraft.

However, this mighty trunk, the principle of direct reaction, gave birth to a huge crown of the "family tree" of the jet engine family. To get acquainted with the main branches of its crown, crowning the “trunk” of direct reaction. Soon, as you can see from the picture (see below), this trunk is divided into two parts, as if split by a lightning strike. Both new trunks are equally decorated with powerful crowns. This division occurred because all “chemical” jet engines are divided into two classes depending on whether they use ambient air for their operation or not.

One of the newly formed trunks is the class of air-breathing engines (WRE). As the name itself indicates, they cannot operate outside the atmosphere. That's why these engines are the basis modern aviation, both manned and unmanned. WRDs use atmospheric oxygen to burn fuel; without it, the combustion reaction in the engine will not proceed. But still, turbojet engines are currently most widely used.

(turbojet engines), installed on almost all modern aircraft without exception. Like all engines that use atmospheric air, turbojet engines require a special device to compress the air before it is supplied to the combustion chamber. After all, if the pressure in the combustion chamber does not significantly exceed atmospheric pressure, then the gases will not flow out of the engine at a higher speed - it is the pressure that pushes them out. But at a low exhaust speed, the engine thrust will be low, and the engine will consume a lot of fuel; such an engine will not find application. In a turbojet engine, a compressor is used to compress air, and the design of the engine largely depends on the type of compressor. There are engines with axial and centrifugal compressors, axial compressors may have less or less thanks for using our system larger number compression stages, be one or two cascade, etc. To drive the compressor, the turbojet engine has a gas turbine, which gives the engine its name. Because of the compressor and turbine, the engine design is quite complex.

Non-compressor air-breathing engines are much simpler in design, in which the necessary increase in pressure is achieved by other methods, which have names: pulsating and ramjet engines.

In a pulsating engine, this is usually done by a valve grid installed at the engine inlet; when a new portion of the fuel-air mixture fills the combustion chamber and a flash occurs in it, the valves close, isolating the combustion chamber from the engine inlet. As a result, the pressure in the chamber increases, and gases rush out through the jet nozzle, after which the whole process is repeated.

In a non-compressor engine of another type, direct-flow, there is not even this valve grid and the pressure in the combustion chamber increases as a result of the high-speed pressure, i.e. braking the oncoming air flow entering the engine in flight. It is clear that such an engine is capable of operating only when aircraft It's already flying at a fairly high speed; it won't develop any thrust while parked. But at a very high speed, 4-5 times the speed of sound, a ramjet engine develops very high thrust and consumes less fuel than any other “chemical” jet engine under these conditions. That's why ramjet engines.

The peculiarity of the aerodynamic design of supersonic aircraft with ramjet engines (ramjet engines) is due to the presence of special accelerator engines that provide the speed necessary to begin stable operation of the ramjet engine. This makes the tail section of the structure heavier and requires the installation of stabilizers to ensure the necessary stability.

The principle of operation of a jet engine.

Modern powerful jet engines of various types are based on the principle of direct reaction, i.e. creation principle driving force(or thrust) in the form of a reaction (recoil) of a stream of “working substance” flowing from the engine, usually hot gases.

In all engines there are two energy conversion processes. First, the chemical energy of the fuel is converted into thermal energy of combustion products, and then the thermal energy is used to perform mechanical work. Such engines include piston engines of cars, diesel locomotives, steam and gas turbines of power plants, etc.

Let's consider this process in relation to jet engines. Let's start with the combustion chamber of the engine, in which a combustible mixture has already been created in one way or another, depending on the type of engine and type of fuel. This could be, for example, a mixture of air and kerosene, as in the turbojet engine of a modern jet aircraft, or a mixture of liquid oxygen and alcohol, as in some liquid rocket engines, or, finally, some kind of solid fuel for powder rockets. The flammable mixture can burn, i.e. enter into a chemical reaction with the rapid release of energy in the form of heat. The ability to release energy during a chemical reaction is the potential chemical energy of the molecules of the mixture. The chemical energy of molecules is associated with the features of their structure, more precisely, the structure of their electronic shells, i.e. that electron cloud that surrounds the nuclei of the atoms that make up the molecule. As a result of a chemical reaction, in which some molecules are destroyed and others are created, a restructuring of the electron shells naturally occurs. In this restructuring there is a source of released chemical energy. It can be seen that jet engine fuels can only be those substances that, during a chemical reaction in the engine (combustion), release quite a lot of heat and also form a large amount of gases. All these processes occur in the combustion chamber, but let’s focus on the reaction not at the molecular level (this has already been discussed above), but at the “phases” of work. Until combustion has begun, the mixture has a large supply of potential chemical energy. But then the flame engulfed the mixture, another moment - and the chemical reaction was over. Now, instead of molecules of the combustible mixture, the chamber is filled with molecules of combustion products, more densely “packed”. Excess binding energy, which is the chemical energy of the combustion reaction that has taken place, is released. The molecules possessing this excess energy almost instantly transferred it to other molecules and atoms as a result of frequent collisions with them. All molecules and atoms in the combustion chamber began to move randomly, chaotically at a significantly higher speed, and the temperature of the gases increased. This is how the potential chemical energy of the fuel was converted into thermal energy of combustion products.

A similar transition was carried out in all other heat engines, but jet engines are fundamentally different from them with regard to the further fate of the hot combustion products.

After hot gases containing large thermal energy have been generated in a heat engine, this energy must be converted into mechanical energy. After all, engines serve to perform mechanical work, to “move” something, to put it into action, no matter whether it is a dynamo, if asked to be supplemented with drawings of a power plant, a diesel locomotive, a car or an airplane.

In order for the thermal energy of gases to transform into mechanical energy, their volume must increase. With such expansion, gases perform work, which consumes their internal and thermal energy.

In the case of a piston engine, the expanding gases press on the piston moving inside the cylinder, the piston pushes the connecting rod, which then rotates the crankshaft of the engine. The shaft is connected to the rotor of a dynamo, the driving axles of a diesel locomotive or car, or an airplane propeller - the engine performs useful work. IN steam engine, or a gas turbine, the gases, expanding, force the wheel connected to the turbine shaft to rotate - here there is no need for a transmission crank mechanism, which is one of the great advantages of the turbine

Gases, of course, also expand in a jet engine, because without this they do not do work. But the expansion work in that case is not spent on shaft rotation. Associated with a drive mechanism, as in other heat engines. The purpose of a jet engine is different - to create jet thrust, and for this it is necessary that a stream of gases - combustion products - flow out of the engine at high speed: the reaction force of this stream is the thrust of the engine. Consequently, the work of expansion of the gaseous products of fuel combustion in the engine must be spent on accelerating the gases themselves. This means that the thermal energy of gases in a jet engine must be converted into their kinetic energy - the random chaotic thermal movement of molecules must be replaced by their organized flow in one direction common to all.

One of the most important parts of the engine, the so-called jet nozzle, serves this purpose. No matter what type this or that jet engine belongs to, it is necessarily equipped with a nozzle through which hot gases - the products of fuel combustion in the engine - flow out of the engine at great speed. In some engines, gases enter the nozzle immediately after the combustion chamber, for example, in rocket or ramjet engines. In others, turbojet engines, the gases first pass through a turbine, to which they give off part of their thermal energy. In this case, it is used to drive the compressor, which compresses the air in front of the combustion chamber. But, one way or another, the nozzle is the last part of the engine - gases flow through it before leaving the engine.

The jet nozzle can have different shapes, and, moreover, different designs depending on the type of engine. The main thing is the speed at which gases flow out of the engine. If this outflow velocity does not exceed the speed with which sound waves propagate in the outflowing gases, then the nozzle is a simple cylindrical or tapered section of pipe. If the outflow speed should exceed the speed of sound, then the nozzle is shaped like an expanding pipe or first narrowing and then expanding (Lavl nozzle). Only in a pipe of this shape, as theory and experience show, can gas be accelerated to supersonic speeds and crossed the “sound barrier.”

Jet engine diagram

The turbofan engine is the most widely used jet engine in civil aviation.

Fuel, entering the engine (1), is mixed with compressed air and burns in the combustion chamber (2). The expanding gases rotate high-speed (3) and low-speed turbines, which, in turn, drive the compressor (5), which pushes air into the combustion chamber, and fans (6), which drive air through this chamber and direct it into the exhaust pipe. By displacing air, fans provide additional thrust. An engine of this type is capable of developing thrust up to 13,600 kg.

Conclusion

The jet engine has many wonderful features, but the main one is this. A rocket does not need earth, water, or air to move, since it moves as a result of interaction with gases formed during the combustion of fuel. Therefore, the rocket can move in airless space.

K. E. Tsiolkovsky is the founder of the theory of space flight. Scientific proof of the possibility of using a rocket for flights into outer space, beyond the Earth's atmosphere and to other planets of the solar system was given for the first time by Russian scientist and inventor Konstantin Eduardovich Tsiolkovsky

Bibliography

Encyclopedic Dictionary of Young Technicians.

Thermal Phenomena in Technology.

Materials from the site http://goldref.ru/;

1. Jet movement (2)

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3. Reactive BM-13 Katyusha multiple launch rocket system

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Jet engines are currently widely used in connection with the exploration of outer space. They are also used for meteorological and military missiles of various ranges. In addition, all modern high-speed aircraft are equipped with air-breathing engines.

IN outer space it is impossible to use any other engines except jet engines: there is no support (solid liquid or gaseous), starting from which spaceship could get a boost. The use of jet engines for aircraft and rockets that do not go beyond the atmosphere is due to the fact thatwhat exactly jet engines can provide maximum speed flight.

Jet engine structure.

Simply based on the principle of operation: outside air (in rocket engines - liquid oxygen) is sucked intoturbine, there it mixes with fuel and burns at the end of the turbine to form the so-called. “working fluid” (jet stream), which moves the car.

At the beginning of the turbine there is fan, which sucks air from external environment into turbines. There are two main tasks- primary air intake and cooling of the entire enginethe engine as a whole by pumping air between the outer shell of the engine and the internal parts. This cools the mixing and combustion chambers and prevents them from collapsing.

Behind the fan is a powerful compressor, which forces air under high pressure into the combustion chamber.

The combustion chamber mixes fuel with air. After the formation of the fuel-air mixture, it is ignited. During the combustion process, significant heating of the mixture and surrounding parts occurs, as well as volumetric expansion. Actually, a jet engine uses a controlled explosion to propel itself. The combustion chamber of a jet engine is one of the hottest parts of it. She needs constant intensive cooling. But this is not enough. The temperature in it reaches 2700 degrees, so it is often made of ceramics.

After the combustion chamber, the burning fuel-air mixture is directed directly into turbine. The turbine consists of hundreds of blades on which the jet stream presses, causing the turbine to rotate. The turbine in turn rotates shaft, on which they are located fan And compressor. Thus, the system is closed and requires only a supply fuel and air for its functioning.

There are two main classes of jet engines bodies:

Jet engines- a jet engine in which atmospheric air is used as the main working fluid in the thermodynamic cycle, as well as when creating engine jet thrust. Such engines use the energy of oxidation of combustible air taken from the atmosphere with oxygen. The working fluid of these engines is a mixture of productscombustion with other components of the intake air.

Rocket engines- contain all components of the working fluid on board and able to work in any environment, including in airless space.

Types of jet engines.

- Classic jet engine- used mainly on fighter aircraft in various modifications.