Abstract: Jet propulsion in nature and technology. Jet propulsion in science, in everyday life, in nature and in technology. Jet propulsion: examples, photos

This turntable can be called the world's first steam jet turbine.

Chinese rocket

Even earlier, many years before Heron of Alexandria, China also invented jet engine a slightly different device, now called fireworks rocket. Fireworks rockets should not be confused with their namesakes - signal rockets, which are used in the army and navy, and are also launched on national holidays under the roar of artillery fireworks. Flares are simply bullets compressed from a substance that burns with a colored flame. They are fired from large-caliber pistols - rocket launchers.

Chinese rocket It is a cardboard or metal tube, closed at one end and filled with a powder composition. When this mixture is ignited, a stream of gases escapes at high speed from open end tube, causes the rocket to fly in the direction opposite to the direction of the gas jet. Such a rocket can take off without the help of a rocket launcher. A stick tied to the rocket body makes its flight more stable and straight.

Sea inhabitants

In the animal world:

Jet propulsion is also found here. Cuttlefish, octopuses and some other cephalopods have neither fins nor a powerful tail, but swim no worse than others sea ​​inhabitants. These soft-bodied creatures have a fairly capacious sac or cavity in their body. Water is drawn into the cavity, and then the animal pushes this water out with great force. The reaction of the ejected water causes the animal to swim in the direction opposite to the direction of the stream.

Falling cat

But the most interesting way the movements were demonstrated by an ordinary cat.

About a hundred and fifty years ago, a famous French physicist Marcel Depres stated:

But you know, Newton's laws are not entirely true. The body can move with internal forces, not relying on anything and not starting from anything.

Where is the evidence, where are the examples? - the listeners protested.

Want proof? If you please. A cat accidentally falling off a roof is proof! No matter how the cat falls, even head down, it will definitely stand on the ground with all four paws. But a falling cat does not rely on anything and does not push away from anything, but turns over quickly and deftly. (Air resistance can be neglected - it is too insignificant.)

Indeed, everyone knows this: cats, falling; always manage to get back on their feet.

Cats do this instinctively, but humans can do the same consciously. Swimmers who jump from a platform into the water know how to perform a complex figure - a triple somersault, that is, turn over three times in the air, and then suddenly straighten up, stop the rotation of their body and dive into the water in a straight line.

The same movements - without interaction with any foreign object, happens to be observed in the circus during the performance of acrobats - trapeze gymnasts.

The falling cat was photographed with a film camera and then on the screen they examined, frame by frame, what the cat does when it flies in the air. It turned out that the cat was quickly twirling its paw. The rotation of the paw causes a response movement of the entire body, and it turns in the direction opposite to the movement of the paw. Everything happens in strict accordance with Newton's laws, and it is thanks to them that the cat gets on its feet.

The same thing happens in all cases where a living creature, without any apparent reason, changes its movement in the air.

Jet boat

The inventors had an idea, why not adopt their swimming method from cuttlefish. They decided to build a self-propelled ship with jet engine. The idea is definitely feasible. True, there was no confidence in success: the inventors doubted whether such a thing would turn out jet boat better than a regular screw. It was necessary to do an experiment.

They selected an old tug steamer, repaired its hull, removed the propellers, and installed a water jet pump in the engine room. This pump pumped sea water and through a pipe pushed it behind the stern with a strong jet. The steamer floated, but it still moved slower than the screw steamer. And this can be explained simply: an ordinary propeller rotates behind the stern, unconstrained, with only water around it; The water in the water-jet pump was driven by almost exactly the same screw, but it no longer rotated on the water, but in a tight pipe. Friction of the water jet against the walls occurred. Friction weakened the pressure of the jet. A steamboat with a water-jet propulsion sailed slower than a screw-propelled one and consumed more fuel.

However, they did not refuse to build such ships: they found important advantages. A boat equipped with a propeller must sit deep in the water, otherwise the propeller will uselessly foam the water or spin in the air. Therefore, screw steamers are afraid of shallows and riffles; they cannot sail in shallow water. And water-jet steamers can be built shallow-draft and flat-bottomed: they don’t need depth - where the boat goes, the water-jet steamer will go.

The first water-jet boats in the Soviet Union were built in 1953 at the Krasnoyarsk shipyard. They are designed for small rivers where ordinary steamboats cannot navigate.

Engineers, inventors and scientists began to study jet propulsion especially diligently when firearms. The first guns - all kinds of pistols, muskets and self-propelled guns - hit a person hard in the shoulder with each shot. After several dozen shots, the shoulder began to hurt so much that the soldier could no longer aim. The first cannons - squeaks, unicorns, culverins and bombards - jumped back when fired, so that it happened that the gunners-artillerymen were crippled if they did not have time to dodge and jump to the side.

The recoil of the gun interfered with accurate shooting, because the gun flinched before the cannonball or grenade left the barrel. This threw off the lead. The shooting turned out to be aimless.

Ordnance engineers began combating recoil more than four hundred and fifty years ago. First, the carriage was equipped with a coulter, which crashed into the ground and served as a strong support for the gun. Then they thought that if the gun was properly supported from behind, so that there was nowhere for it to roll away, then the recoil would disappear. But it was a mistake. The law of conservation of momentum was not taken into account. The guns broke all the supports, and the carriages became so loose that the gun became unsuitable for combat work. Then the inventors realized that the laws of motion, like any laws of nature, cannot be remade in their own way, they can only be “outwitted” with the help of science - mechanics.

They left a relatively small opener at the carriage for support, and placed the cannon barrel on a “sled” so that only one barrel rolled away, and not the entire gun. The barrel is connected to a compressor piston, which moves in its cylinder exactly like a piston steam engine. But in the cylinder of a steam engine there is steam, and in a gun compressor there is oil and a spring (or compressed air).

When the gun barrel rolls back, the piston compresses the spring. At this time, the oil is forced through small holes in the piston on the other side of the piston. Strong friction arises, which partially absorbs the movement of the rolling barrel, making it slower and smoother. Then the compressed spring straightens and returns the piston, and with it the gun barrel, to its original place. The oil presses on the valve, opens it and flows freely back under the piston. During rapid fire, the gun barrel moves almost continuously back and forth.

In a gun compressor, recoil is absorbed by friction.

Muzzle brake

When the power and range of the guns increased, the compressor was not enough to neutralize the recoil. It was invented to help him muzzle brake.

The muzzle brake is just a short steel pipe, mounted on the cut of the trunk and serving as its continuation. Its diameter is larger than the diameter of the barrel, and therefore it does not in any way interfere with the projectile flying out of the barrel. Several oblong holes are cut around the circumference of the tube walls.

Powder gases flying out of the gun barrel following the projectile immediately diverge to the sides, and some of them fall into the holes of the muzzle brake. These gases hit the walls of the holes with great force, are repelled from them and fly out, but not forward, but slightly askew and backward. At the same time, they press forward on the walls and push them, and with them the entire barrel of the gun. They help the fire monitor because they tend to cause the barrel to roll forward. And while they were in the barrel, they pushed the gun back. The muzzle brake significantly reduces and dampens recoil.

Other inventors took a different route. Instead of fighting reactive movement of the barrel and try to extinguish it, they decided to use the gun's rollback to good effect. These inventors created many types of automatic weapons: rifles, pistols, machine guns and cannons, in which the recoil serves to eject the spent cartridge case and reload the weapon.

Rocket artillery

You don’t have to fight recoil at all, but use it: after all, action and reaction (recoil) are equivalent, equal in rights, equal in magnitude, so let reactive action of powder gases, instead of pushing the gun barrel back, sends the projectile forward towards the target. This is how it was created rocket artillery. In it, a jet of gases hits not forward, but backward, creating a forward-directed reaction in the projectile.

For rocket gun the expensive and heavy barrel turns out to be unnecessary. A cheaper, simple iron pipe works perfectly to direct the flight of the projectile. You can do without a pipe at all, and make the projectile slide along two metal slats.

In its design, a rocket projectile is similar to a fireworks rocket, it is only larger in size. In its head part, instead of the composition for color sparkler an explosive charge of great destructive power is placed. The middle of the projectile is filled with gunpowder, which, when burned, creates a powerful stream of hot gases that pushes the projectile forward. In this case, the combustion of gunpowder can last a significant part of the flight time, and not just the short period of time while an ordinary projectile advances in the barrel of an ordinary gun. The shot is not accompanied by such a loud sound.

Rocket artillery is no younger than ordinary artillery, and perhaps even older: ancient Chinese and Arabic books written more than a thousand years ago report on the combat use of rockets.

In descriptions of battles of later times, no, no, and there will be a mention of combat missiles. When British troops conquered India, Indian rocket warriors, with their fire-tailed arrows, terrified the British invaders who enslaved their homeland. For the British at that time, jet weapons were a novelty.

Rocket grenades invented by the general K. I. Konstantinov, the courageous defenders of Sevastopol in 1854-1855 repelled the attacks of the Anglo-French troops.

Rocket

The huge advantage over conventional artillery - there was no need to carry heavy guns - attracted the attention of military leaders to rocket artillery. But an equally major drawback prevented its improvement.

The fact is that the propelling charge, or, as they used to say, the force charge, could only be made from black powder. And black powder is dangerous to handle. It happened that during production missiles the propellant exploded and the workers died. Sometimes the rocket exploded upon launch, killing the gunners. Making and using such weapons was dangerous. That's why it hasn't become widespread.

The work that began successfully, however, did not lead to the construction of an interplanetary spacecraft. German fascists prepared and unleashed a bloody world war.

Missile

The shortcomings in the production of rockets were eliminated by Soviet designers and inventors. During the Great Patriotic War they gave our army excellent rocket weapons. Guards mortars were built - "Katyusha" and RS ("eres") were invented - rockets.

In terms of quality, Soviet rocket artillery surpassed all foreign models and caused enormous damage to enemies.

Defending the Motherland, Soviet people was forced to put all the achievements of rocket technology into the service of defense.

In fascist states, many scientists and engineers, even before the war, were intensively developing projects for inhumane weapons of destruction and mass murder. This they considered the purpose of science.

Self-driving aircraft

During the war, Hitler's engineers built several hundred self-driving aircraft: V-1 projectiles and V-2 rockets. These were cigar-shaped shells, 14 meters long and 165 centimeters in diameter. The deadly cigar weighed 12 tons; of which 9 tons are fuel, 2 tons are casing and 1 ton are explosives. "V-2" flew at speeds of up to 5,500 kilometers per hour and could rise to a height of 170-180 kilometers.

These means of destruction did not differ in hit accuracy and were only suitable for firing at such large targets as large and densely populated cities. The German fascists produced the V-2 200-300 kilometers from London in the belief that the city was large - it would hit somewhere!

It is unlikely that Newton could have imagined that his witty experience and the laws of motion he discovered would form the basis of weapons created by bestial anger towards people, and entire blocks of London would turn into ruins and become the graves of people captured by the raid of the blind “FAU”.

Spaceship

For many centuries, people have cherished the dream of flying in interplanetary space, of visiting the Moon, mysterious Mars and cloudy Venus. Many science fiction novels, novellas and short stories have been written on this topic. Writers sent their heroes to the sky-high distances on trained swans, on balloons, in cannon shells or in some other incredible way. However, all these methods of flight were based on inventions that had no support in science. People only believed that they would someday be able to leave our planet, but did not know how they would be able to do this.

Wonderful scientist Konstantin Eduardovich Tsiolkovsky in 1903 for the first time gave scientific basis the idea of ​​space travel. He proved that people can leave Earth And vehicle a rocket will serve for this, because a rocket is the only engine that does not need any external support for its movement. That's why rocket capable of flying in airless space.

In terms of its structure, the spacecraft should be similar to a rocket, only in its head there will be a cabin for passengers and instruments, and the rest of the space will be occupied by a supply of combustible mixture and an engine.

To give the ship the required speed, the right fuel is required. Gunpowder and other explosives are by no means suitable: they are both dangerous and burn too quickly, not providing long-term movement. K. E. Tsiolkovsky recommended using liquid fuel: alcohol, gasoline or liquefied hydrogen, burning in a stream of pure oxygen or some other oxidizing agent. Everyone recognized the correctness of this advice, because they did not know the best fuel at that time.

The first rocket with liquid fuel, weighing sixteen kilograms, was tested in Germany on April 10, 1929. The experimental rocket took off into the air and disappeared from view before the inventor and everyone present were able to trace where it flew. It was not possible to find the rocket after the experiment. The next time, the inventor decided to “outsmart” the rocket and tied a rope four kilometers long to it. The rocket took off, dragging its rope tail behind it. She pulled out two kilometers of rope, broke it and followed her predecessor in an unknown direction. And this fugitive also could not be found.

In the world there are Various types movement as a way of moving bodies from one point in space to another. in nature and technology, which occurs when a part of it is separated from the body at any speed, is certainly less common, but still occupies its rightful place. And in technology, scientists actually “spied” jet propulsion from living nature. And they used it quite successfully in their inventions. Our material will tell you about this and much more, no less interesting.

Reactivity in animals

For example, when swimming in sea ​​wave, many people often came face to face with representatives of aquatic fauna - jellyfish. But few people thought that these animals use a reactive type for movement. Also, marine plankton and the larvae of some insect species move using reactivity. And, by the way, in technology, jet propulsion, or rather its efficiency, is sometimes much lower than that of these creations of nature.

Many shellfish also use it. And they move, for example, due to the reactivity of the stream of water released from the animal’s shell when the valves are compressed. The squid still has something skillfully developed by nature. Due to this, there is a sharp movement of it into aquatic environment, and sometimes this sea creature even takes off into the air!

Jet propulsion in technology. Examples

This method is also widely used in the modern era. It should be noted that in technology, reactive movement largely copies natural reactivity. Even in ancient times in China (first millennium AD), bamboo pipes filled with gunpowder were invented, which were used mainly for fun. They were based on the reactive principle. And Newton at one time came up with not only the same name but also the prototype of a car that was equipped with a jet engine.

For human flight

People realized that jet propulsion could be used in technology for flight. The first author of such a project is considered to be the Narodnaya Volya member Kibalchich, who literally a few days before his death (he was sentenced to death as a participant in the assassination attempt on the Tsar) developed and recorded scientific data. Tsiolkovsky developed Kibalchich's ideas and developed a mathematical equation that was important for astronautics, allowing the use of the reactivity principle. It was he who described in his works the principles of operation of jet units using liquid fuel.

Jet engine

In its design, it converts fuel chemical energy into kinetic energy - already a gas jet. In this case, the speed of the opposite direction is acquired. Tsiolkovsky's ideas were developed by Korolev, and the launch of the first satellite using it was carried out in 1957 in the USSR. And the first person to overcome gravity with the help of jet propulsion was Soviet pilot Gagarin in 1961. He flew around the planet on the Vostok spacecraft.

Rocket device

To put it simply, a modern launch vehicle consists of a shell and fuel (plus an oxidizer). The shell contains a payload - a space capsule, which is launched into Earth orbit. Control devices and the engine are also located here. Everything else usable area rockets are occupied by fuel and an oxidizer designed to support the combustion process (after all, there is no oxygen in space).

In the combustion chamber, fuel is converted into gas under high pressure and very high temperatures. Due to the difference in pressure outside the spacecraft and in the combustion chambers, the gas rushes out, due to which the rocket moves.

The law of conservation of momentum is of great importance when considering jet motion.
Under jet propulsion understand the movement of a body that occurs when some part of it separates with a certain speed relative to it, for example, when combustion products flow out of a jet nozzle aircraft. In this case, the so-called Reactive force pushing the body.
The peculiarity of the reactive force is that it arises as a result of the interaction between parts of the system itself without any interaction with external bodies.
While the force imparting acceleration, for example, to a pedestrian, a ship or an airplane, arises only due to the interaction of these bodies with the ground, water or air.

Thus, the movement of a body can be obtained as a result of the flow of a stream of liquid or gas.

Jet motion in nature inherent mainly in living organisms living in an aquatic environment.

In technology, jet propulsion is used in river transport (water jet engines), in the automotive industry (racing cars), in military affairs, in aviation and astronautics.
All modern high-speed aircraft are equipped with jet engines, because... they are able to provide the required flight speed.
It is impossible to use engines other than jet engines in outer space, since there is no support there from which acceleration could be achieved.

History of the development of jet technology

The creator of the Russian combat missile was artillery scientist K.I. Konstantinov. Weighing 80 kg, the flight range of Konstantinov’s rocket reached 4 km.

The idea of ​​​​using jet propulsion in an aircraft, the project of a jet aeronautical device, was put forward in 1881 by N.I. Kibalchich.

In 1903, the famous physicist K.E. Tsiolkovsky proved the possibility of flight in interplanetary space and developed a design for the first rocket plane with a liquid-propellant engine.

K.E. Tsiolkovsky designed a space rocket train made up of a number of rockets that operate alternately and fall away as fuel is used up.

Principles of jet engines

The basis of any jet engine is the combustion chamber, in which the combustion of fuel produces gases that have very high temperature and exerting pressure on the chamber walls. Gases escape from a narrow rocket nozzle at high speed and create jet thrust. In accordance with the law of conservation of momentum, the rocket acquires speed in the opposite direction.

The momentum of the system (rocket-combustion products) remains equal to zero. Since the mass of the rocket decreases, even with a constant gas flow rate, its speed will increase, gradually reaching its maximum value.
The motion of a rocket is an example of the motion of a body with variable mass. To calculate its speed, the law of conservation of momentum is used.

Jet engines are divided into rocket engines and air-breathing engines.

Rocket engines Available with solid or liquid fuel.
In solid fuel rocket engines, the fuel, which contains both fuel and oxidizer, is trapped inside the engine's combustion chamber.
IN liquid jet engines, intended to run spaceships, fuel and oxidizer are stored separately in special tanks and supplied to the combustion chamber using pumps. They can use kerosene, gasoline, alcohol, liquid hydrogen, etc. as fuel, and liquid oxygen, nitric acid, etc. as the oxidizing agent necessary for combustion.

Modern three-stage space rockets are launched vertically, and after passing through the dense layers of the atmosphere they are transferred to flight in a given direction. Each rocket stage has its own fuel tank and oxidizer tank, as well as its own jet engine. As the fuel burns, the spent rocket stages are discarded.

Jet engines currently used mainly in aircraft. Their main difference from rocket engines is that the oxidizer for fuel combustion is oxygen from the air entering the engine from the atmosphere.
Air-breathing engines include turbocompressor engines with both an axial and a centrifugal compressor.
The air in such engines is sucked in and compressed by a compressor driven by gas turbine. The gases leaving the combustion chamber create a reactive thrust and rotate the turbine rotor.

At very high flight speeds, compression of gases in the combustion chamber can be achieved due to the oncoming oncoming air flow. There is no need for a compressor.

Newton's laws help explain a very important mechanical phenomenon - jet propulsion. This is the name given to the movement of a body that occurs when some part of it is separated from it at any speed.

Let's take, for example, a children's rubber ball, inflate it and release it. We will see that when the air begins to leave it in one direction, the ball itself will fly in the other. This is reactive movement.

Some representatives of the animal world move according to the principle of jet propulsion, such as squids and octopuses. Periodically throwing out the water they absorb, they are able to reach speeds of up to 60-70 km/h. Jellyfish, cuttlefish and some other animals move in a similar way.

Examples of jet propulsion can also be found in the plant world. For example, the ripened fruits of a “mad” cucumber, with the slightest touch, bounce off the stalk and a bitter liquid with seeds is forcefully thrown out of the hole formed at the site of the separated stalk; the cucumbers themselves fly off in the opposite direction.

The reactive motion that occurs when water is released can be observed in the following experiment. Pour water into a glass funnel connected to a rubber tube with an L-shaped tip (Fig. 20). We will see that when water begins to flow out of the tube, the tube itself will begin to move and deviate in the direction opposite to the direction of flow of water.

Flights are based on the principle of jet propulsion missiles. A modern space rocket is a very complex aircraft consisting of hundreds of thousands and millions of parts. The mass of the rocket is enormous. It consists of the mass of the working fluid (i.e., hot gases formed as a result of fuel combustion and emitted in the form of a jet stream) and the final or, as they say, “dry” mass of the rocket remaining after the working fluid is ejected from the rocket.

The “dry” mass of the rocket, in turn, consists of the mass of the structure (i.e. the rocket shell, its engines and control system) and the mass of the payload (i.e. scientific equipment, the body of the spacecraft launched into orbit, the crew and the system ship life support).

As the working fluid expires, the released tanks, excess parts of the shell, etc. begin to burden the rocket with unnecessary cargo, making it difficult to accelerate. Therefore, to achieve cosmic speeds, composite (or multi-stage) rockets are used (Fig. 21). At first, only the first stage 1 blocks work in such rockets. When the fuel reserves in them run out, they are separated and the second stage 2 is turned on; after the fuel in it is exhausted, it is also separated and the third stage 3 is turned on. The satellite or any other spacecraft located in the head of the rocket is covered with a head fairing 4, the streamlined shape of which helps to reduce air resistance when the rocket flies in the Earth's atmosphere.

When a jet of gas is ejected from a rocket at high speed, the rocket itself rushes in the opposite direction. Why is this happening?

According to Newton's third law, the force F with which the rocket acts on the working fluid is equal in magnitude and opposite in direction to the force F" with which the working fluid acts on the rocket body:

Force F" (which is called reactive force) accelerates the rocket.

From equality (10.1) it follows that the impulse imparted to the body equal to the product force for the duration of its action. Therefore, equal forces acting for the same time impart equal impulses to bodies. IN in this case the impulse m r v r acquired by the rocket must be the pulse m gas v gas of the ejected gases:

m р v р = m gas v gas

It follows that the speed of the rocket

Let's analyze the resulting expression. We see that the speed of the rocket is greater, the greater the speed of the emitted gases and the greater the ratio of the mass of the working fluid (i.e., the mass of the fuel) to the final (“dry”) mass of the rocket.

Formula (12.2) is approximate. It does not take into account that as the fuel burns, the mass of the flying rocket becomes less and less. The exact formula for rocket speed was first obtained in 1897 by K. E. Tsiolkovsky and therefore bears his name.

The Tsiolkovsky formula allows you to calculate the fuel reserves required to impart a given rocket speed. Table 3 shows the ratio of the initial mass of the rocket m0 to its final mass m, corresponding to different velocities of the rocket at a gas jet speed (relative to the rocket) v = 4 km/s.

For example, to impart to a rocket a speed exceeding the speed of gas flow by 4 times (v p = 16 km/s), it is necessary that the initial mass of the rocket (including fuel) exceed the final (“dry”) mass of the rocket by 55 times (m 0 /m = 55). This means that the lion's share of the total mass of the rocket at launch should be the mass of fuel. The payload, in comparison, should have a very small mass.

An important contribution to the development of the theory of jet propulsion was made by a contemporary of K. E. Tsiolkovsky, the Russian scientist I. V. Meshchersky (1859-1935). The equation of motion of a body with variable mass is named after him.

1. What is jet propulsion? Give examples. 2. In the experiment shown in Figure 22, when water flows out through curved tubes, the bucket rotates in the direction indicated by the arrow. Explain the phenomenon. 3. What determines the speed acquired by a rocket after fuel combustion?

Today, most people primarily associate jet propulsion, of course, with the latest scientific and technical developments. From physics textbooks we know that by “reactive” we mean movement that occurs as a result of the separation of any part of it from an object (body). Man wanted to rise into the sky to the stars, he wanted to fly, but he was able to realize his dream only with the advent of jet aircraft and stepped spaceships, capable of traveling over vast distances, accelerating to supersonic speeds, thanks to the modern jet engines installed on them. Designers and engineers were developing the possibility of using jet propulsion in engines. Science fiction writers also did not stand aside, offering the most incredible ideas and ways to achieve this goal. Surprisingly, this principle of movement is widespread in wildlife. Just look around, you can notice the inhabitants of the seas and land, among which there are plants, the basis of whose movement is the reactive principle.

Story

Even in ancient times, scientists studied and analyzed with interest the phenomena associated with jet motion in nature. One of the first to theoretically substantiate and describe its essence was Heron, a mechanic and theorist Ancient Greece, who invented the first steam engine, named after him. The Chinese were able to find a reactive method practical use. They were the first, taking as a basis the method of movement of cuttlefish and octopuses, to invent rockets back in the 13th century. They were used in fireworks, making a great impression, and also as signal flares, and possibly military missiles that were used as rocket artillery. Over time, this technology came to Europe.

The pioneer of modern times was N. Kibalchich, who came up with a design for a prototype aircraft with a jet engine. He was an outstanding inventor and a convinced revolutionary, for which he was imprisoned. It was while in prison that he made history by creating his project. After his execution for active revolutionary activities and speaking out against the monarchy, his invention was forgotten on the archive shelves. After some time, K. Tsiolkovsky was able to improve Kibalchich’s ideas, proving the possibility of exploring outer space through the reactive propulsion of spacecraft.

Later, during the Great Patriotic War, the famous Katyushas, ​​field rocket artillery systems, appeared. This is the affectionate name people informally called powerful installations, which used the forces of the USSR. It is not known for certain why the weapon received this name. The reason for this was either the popularity of Blanter’s song, or the letter “K” on the body of the mortar. Over time, front-line soldiers began to give nicknames to other weapons, thus creating a new tradition. The Germans did this battle rocket launcher called "Stalin's organ" for appearance, which reminded musical instrument and the piercing sound that came from the launching rockets.

Vegetable world

Representatives of the fauna also use the laws of jet propulsion. Most of the plants that have these properties are annuals and young perennials: thorny carp, common spadefoot spadefoot, impatiens heartwood, two-cut pikulnik, three-veined meringia.

The thorny cucumber, also known as the crazy cucumber, belongs to the pumpkin family. This plant reaches large sizes, has a thick root with a rough stem and large leaves. Grows in the area Central Asia, Mediterranean, Caucasus, quite common in southern Russia and Ukraine. Inside the fruit, during the period of seed ripening, it is transformed into mucus, which, under the influence of temperatures, begins to ferment and release gas. Closer to ripening, the pressure inside the fruit can reach 8 atmospheres. Then, with a light touch, the fruit breaks away from the base and the seeds with liquid fly out of the fruit at a speed of 10 m/s. Due to its ability to shoot 12 m in length, the plant was called the “ladies pistol”.

Impatiens heartwood is a widespread annual species. It is found, as a rule, in shady forests, along the banks of rivers. Once in the northeastern part North America and in South Africa, settled in successfully. Touch-me-not is propagated by seeds. The seeds of the impatiens are small, weighing no more than 5 mg, which are thrown at a distance of 90 cm. Thanks to this method of seed dispersal, the plant got its name.

Animal world

Jet propulsion - Interesting Facts relating to the animal world. In cephalopods, jet propulsion occurs by means of water exhaled through a siphon, which usually tapers to a small opening to receive maximum speed exhale. Water passes through the gills before exhalation, fulfilling the dual purpose of breathing and movement. Sea hares, also known as gastropods, use similar means of propulsion, but without the complex neurological apparatus of cephalopods, they move more clumsily.

Some knightfish have also developed jet propulsion, forcing water over their gills to complement fin movement.

In dragonfly larvae, reactive force is achieved by displacing water from a specialized cavity in the body. Scallops and cardids, siphonophores, tunics (such as salps) and some jellyfish also use jet propulsion.

Most part of time scallops They lie calmly on the bottom, but in case of danger, they quickly close the doors of their shell, so they push out the water. This behavior mechanism also speaks of the use of the principle of reactive movement. Thanks to it, scallops can float up and move over long distances using the opening-closing technique of the shell.

The squid also uses this method, absorbs water, and then pushes it through the funnel with great force and moves at a speed of at least 70 km/h. By collecting the tentacles into one knot, the squid's body forms a streamlined shape. Using this squid engine as a basis, engineers designed a water cannon. The water in it is sucked into the chamber and then thrown out through the nozzle. Thus, the ship is sent to reverse side from the ejected jet.

Compared to squids, salps use the most efficient engines, spending an order of magnitude less energy than squids. Moving, the salpa releases water into the hole in the front, and then enters the wide cavity where the gills are stretched. After a sip, the hole closes, and with the help of contracting longitudinal and transverse muscles that compress the body, water is released through the hole at the back.

The most unusual of all locomotion mechanisms is the common cat. Marcel Despres suggested that a body is capable of moving and changing its position even with the help of internal forces alone (without pushing off or relying on anything), from which it could be concluded that Newton’s laws may be erroneous. The proof of his assumption could be a cat that fell from a height. If she falls upside down, she will still land on all her paws; this has already become a kind of axiom. Having photographed the cat’s movement in detail, we were able to see from the frames everything that it did in the air. We saw her move her paw, which caused a response from her body, turning in the other direction relative to the movement of her paw. Acting according to Newton's laws, the cat landed successfully.

In animals, everything happens at the level of instinct; humans, in turn, do it consciously. Professional swimmers, having jumped from the tower, manage to turn around three times in the air, and having managed to stop the rotation, straighten up strictly vertically and dive into the water. The same principle applies to aerial circus gymnasts.

No matter how much people try to surpass nature by improving the inventions it has created, we still have not yet achieved that technological perfection when airplanes could repeat the actions of a dragonfly: hover in the air, instantly back up or move to the side. And all this happens at high speed. Perhaps a little more time will pass and airplanes, thanks to adjustments to the aerodynamics and jet capabilities of dragonflies, will be able to make sharp turns and become less susceptible to external conditions. Having looked at nature, man can still improve a lot for the benefit of technical progress.