Reactive motion in technology, nature. Biophysics: jet propulsion in living nature Manifestation of jet propulsion in nature

Was not the world's first jet engine. scientists have observed and investigated even before Newton's experiments and up to the present day: Jet propulsion aircraft.

Heron's spinner

Eighteen hundred years before Newton's experiments first steam jet engine made by a wonderful inventor Heron of Alexandria-ancient Greek mechanic, his invention was named Heron's spinner.

Heron of Alexandria, an ancient Greek mechanic, invented the world's first steam jet turbine. We know little about Heron of Alexandria. He was the son of a barber and a disciple of another famous inventor, Ctesibia... Geron lived in Alexandria about two thousand one hundred and fifty years ago. In the device invented by Heron, steam from a boiler, under which a fire was burning, passed through two pipes into an iron ball. The tubes simultaneously served as an axis around which this ball could rotate. Two other tubes, bent like the letter "L", were attached to the ball so that they allowed steam to escape out of the ball. When a fire was made under the cauldron, the water boiled and steam rushed into the iron ball, and from it, through curved pipes, it flew out with force. At the same time, the ball rotated in the direction opposite to the one into which the steam jets flew out, this happens in accordance with. This turntable can be called the world's first steam jet turbine.

Chinese rocket

Even earlier, many years before the Heron of Alexandria, in China they also invented jet engine somewhat different device, now called fireworks rocket... Fireworks rockets should not be confused with their namesake - signal flares, which are used in the army and navy, and are also fired on days of national holidays to the sound of artillery salutes. Signal flares are simply bullets compressed from a substance that burns with a colored flame. They are fired from large-caliber pistols - rocket launchers.

Signal flares are bullets compressed from a substance that burns with a colored flame. Chinese rocket is a cardboard or metal tube, closed at one end and filled with a powder composition. When this mixture is ignited, a jet of gases, escaping at high speed from the open end of the 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 pistol-rocket launcher. A stick attached to the body of the rocket makes its flight more stable and straightforward.

Fireworks using Chinese rockets.

Inhabitants of the sea

In the animal world:

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

Falling cat

But the most interesting way of movement was demonstrated by an ordinary cat... A hundred and fifty years ago, a famous French physicist Marcel Despres stated:

- Do you know, Newton's laws are not entirely correct. The body can move with the help of internal forces, without relying on anything and not pushing away from anything. - Where is the evidence, where are examples? - the listeners protested. - Want proof? Excuse me. A cat that accidentally fell off the roof is proof! No matter how the cat falls, even head down, it will definitely stand on the ground with all four legs. But the falling cat does not lean on anything and does not push off from anything, but turns over quickly and dexterously. (Air resistance can be neglected - it is too negligible.)

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

The falling cat stands on four legs. Cats do it instinctively, and humans can do the same consciously. Swimmers jumping from a tower into the water are able to perform a complex figure - a triple somersault, that is, turn over three times in the air, and then suddenly straighten up, suspend the rotation of their bodies and dive into the water in a straight line. The same movements, - without interaction with any foreign object, happen to be observed in the circus during the performance of acrobats - aerial gymnasts.

Performance of acrobats - aerial gymnasts. The falling cat was photographed with a film camera and then viewed frame by frame on the screen, which is what a cat does when it flies in the air. It turned out that the cat quickly twirls its paw. The rotation of the paws causes a reciprocal movement - the reaction of the whole body, and it turns in the direction opposite to the movement of the paws. Everything happens in strict accordance with Newton's laws, and it is thanks to them that the cat gets on its feet. The same happens in all cases when a living creature changes its movement in the air for no apparent reason.

Jet boat

The inventors had an idea, why not adopt their way of swimming from cuttlefish. They decided to build a self-propelled ship with jet engine... The idea is definitely feasible. True, there was no confidence in luck: the inventors doubted whether such jet boat better than the usual screw. It was necessary to make an experiment.

A jet boat is a self-propelled vessel with a jet engine. They chose an old tugboat, repaired its hull, removed the propellers, and put a water pump in the engine room. This pump pumped the seawater and pushed it through the pipe behind the stern with a strong stream. The steamer was sailing, but it still moved more slowly than the screw steamer. And this can be explained simply: an ordinary propeller rotates behind the stern unrestricted by anything, there is only water around it; the water in the jet pump was set in motion by almost exactly the same propeller, but it no longer rotated on the water, but in a tight pipe. Friction of the water jet against the walls arose. Friction weakened the thrust of the jet. The steamboat with a water-jet propeller sailed slower than the propeller one and consumed more fuel. However, they did not abandon the construction of such ships: they found important advantages. A boat equipped with a propeller must sit deep in the water, otherwise the propeller will be uselessly foaming the water or spinning in the air. Therefore, screw steamers are afraid of shoals and rifts, they cannot sail in shallow water. And water-jet steamers can be built shallow-draft and flat-bottomed: they do not need depth - where the boat will pass, the water-jet steamer will also pass there. The first water jet boats in the Soviet Union were built in 1953 at the Krasnoyarsk shipyard. They are intended for small rivers where conventional steamers cannot sail.

Especially diligently engineers, inventors and scientists were engaged in the study of jet propulsion when firearms... The first guns - all kinds of pistols, muskets and samopals - hit a man in the shoulder with every shot. After several dozen shots, the shoulder began to hurt so much that the soldier could no longer aim. The first cannons - squeaks, unicorns, coolerines and bombards - jumped back when fired, so that, it happened, the gunners-gunners were crippled if they did not have time to dodge and jump aside. The recoil of the gun interfered with accurate shooting, because the gun flinched before the core or grenade flew out of the barrel. This confused the lead. The shooting turned out to be non-aiming.

Shooting with firearms. Artillery engineers began recoil fighting 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 solid support for the gun. Then they thought that if the cannon was properly supported from behind, so that it had nowhere to roll back, then the recoil would disappear. But that was a mistake. The law of conservation of momentum was not taken into account. The cannons broke all the supports, and the carriages were so loosened that the weapon became unsuitable for combat work. Then the inventors realized that the laws of motion, like any laws of nature, cannot be altered in their own way, they can only be "outsmarted" with the help of science - mechanics. At the carriage, they left a relatively small opener for the stop, and put the barrel of the gun on the "slide" so that only one barrel rolled back, and not the entire gun. The barrel was connected to the compressor piston, which moves in its cylinder in the same way as the piston of a steam engine. But in the cylinder of a steam engine there is steam, and in the gun compressor there is oil and a spring (or compressed air). When the barrel of the cannon rolls back, the piston compresses the spring. At the same time, oil is forced through small holes in the piston on the other side of the piston. There is strong friction, which partially absorbs the movement of the recoiling barrel, making it slower and smoother. Then the compressed spring expands 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 barrel of the gun moves forward and backward almost continuously. 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. To help him was invented muzzle brake... The muzzle brake is just a short steel tube attached to the bore and serving as an extension of it. Its diameter is larger than the diameter of the barrel bore, and therefore it does not in the least interfere with the projectile flying out of the barrel. Several oblong holes are cut in the walls of the tube along the circumference.

Muzzle Brake - Reduces the recoil of firearms. Powder gases escaping from the barrel of the gun 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, repel them and fly out, but not forward, but slightly obliquely and backward. At the same time, they press on the walls forward and push them, and with them the entire barrel of the gun. They help the fire monitor spring 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 attenuates recoil. Other inventors took a different path. Instead of fighting jet propulsion and try to extinguish it, they decided to use the rollback of the weapon with the benefit of the cause. These inventors created many examples of automatic weapons: rifles, pistols, machine guns and cannons, in which recoil serves to throw out the used cartridge case and reload the weapon.

Rocket artillery

You can not fight with recoil at all, but use it: after all, action and reaction (recoil) are equivalent, equal, equal, so let reactive effect of powder gases, instead of pushing back the gun barrel, sends the projectile forward at the target. So was created rocket artillery... In it, a jet of gases hits not forward, but backward, creating a forward reaction in the projectile. For jet gun the expensive and heavy barrel turns out to be unnecessary. A cheaper, simple iron tube perfectly serves to direct the flight of the projectile. You can do without a pipe at all, but make the projectile slide along two metal slats. In its structure, a rocket is similar to a fireworks rocket, it is only larger in size. Instead of a compound for colored sparklers, an explosive charge of great destructive force is placed in its head. The middle of the projectile is filled with gunpowder, which, when burning, creates a powerful jet of hot gases that push the projectile forward. In this case, the combustion of gunpowder can last a significant part of the flight time, and not only that short period of time while a conventional projectile moves in the barrel of a conventional cannon. The shot is not accompanied by such a loud sound. Rocket artillery is no younger than ordinary artillery, and perhaps even older than it: ancient Chinese and Arabic books written more than a thousand years ago report the combat use of missiles. In the descriptions of the battles of later times, no, no, and there will be a mention of combat missiles. When the British troops conquered India, the Indian rocket warriors, with their fire-tail arrows, terrified the British invaders who enslaved their homeland. For the British at the time, jet weapons were a curiosity. Rocket grenades invented by the general K. I. Konstantinov, courageous defenders of Sevastopol in 1854-1855 repulsed the attacks of the Anglo-French troops.

Rocket

A huge advantage over ordinary artillery - there was no need to carry heavy guns - attracted the attention of military leaders to rocket artillery. But an equally major drawback hindered its improvement. The fact is that the propelling, or, as they used to say, force charge, they knew how to make only from black powder. And black powder is dangerous to handle. It happened that during the manufacture missiles the propellant exploded and workers died. Sometimes the rocket exploded on launch, and the gunners died. It was dangerous to make and use such weapons. Therefore, it did not become widespread. The work begun successfully, however, did not lead to the construction of an interplanetary spacecraft. German fascists prepared and unleashed a bloody world war.

Missile

The deficiency in the manufacture of missiles was eliminated by Soviet designers and inventors. During the Great Patriotic War they gave our army excellent jet weapons. Guards mortars were built - "Katyushas" and the RS ("eres") were invented - rockets.

Missile. In terms of its quality, Soviet rocket artillery surpassed all foreign models and inflicted tremendous damage on the enemy. Defending the Motherland, the Soviet people were forced to put all the achievements of rocketry into the service of defense. In the fascist states, many scientists and engineers, even before the war, were intensively developing projects for inhuman weapons of destruction and mass murder. They considered this the goal of science.

Self-driving aircraft

During the war, Hitler's engineers built several hundred self-driving aircraft: shells "FAU-1" and rockets "FAU-2". 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 hull and 1 ton is explosive. "FAU-2" flew at a speed of up to 5500 kilometers per hour and could climb 170-180 kilometers in height. These means of destruction did not differ in the accuracy of hitting and were only suitable for firing at such large targets as large and densely populated cities. The German fascists released the "FAU-2" 200-300 kilometers from London in the expectation that the city is large - it will get somewhere! It is unlikely that Newton could have imagined that his witty experience and the laws of motion discovered by him would form the basis of a weapon created by bestial malice towards people, and entire blocks of London would turn to ruins and become the graves of people captured by the FAU's raid of the blind.

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 sky-high distances on trained swans, in balloons, in cannon shells, or in some other incredible way. However, all these flight methods 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 accomplish this. Wonderful scientist Konstantin Eduardovich Tsiolkovsky in 1903 for the first time gave a scientific basis to the idea of space travel... He proved that people can leave the globe and a rocket will serve as a vehicle 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.

Scientist Konstantin Eduardovich Tsiolkovsky - proved that people can leave the globe on a rocket. In terms of its structure, the spacecraft should be similar to a rocket projectile, only in its head part a cabin for passengers and instruments will fit, and the rest of the space will be occupied by a supply of combustible mixture and an engine. To get a ship at the right speed, you need the right fuel. 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 then they did not know the best fuel. The first rocket with liquid fuel, weighing sixteen kilograms, was tested in Germany on April 10, 1929. An experienced rocket took off into the air and disappeared from view before the inventor and everyone present could 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 four kilometers long rope to it. The rocket soared, trailing its rope tail. She pulled out two kilometers of rope, cut it and followed her predecessor in an unknown direction. And this fugitive also could not be found. The first successful flight of a rocket with liquid fuel took place in the USSR on August 17, 1933. The rocket rose, flew its intended distance and landed safely. All these discoveries and inventions are based on Newton's laws.

Reactive motion in nature and technology

ABSTRACT IN PHYSICS

Reactive motion is a movement that occurs when any part of the body is separated from the body at a certain speed.

Reactive force arises without any interaction with external bodies.

The use of jet propulsion in nature

Many of us in our lives met with jellyfish while swimming in the sea. In any case, there are quite enough of them in the Black Sea. But few people thought that jellyfish use jet propulsion for movement. In addition, this is how dragonfly larvae and some species of marine plankton move. And often the efficiency of marine invertebrates using jet propulsion is much higher than that of technological inventions.

Jet propulsion is used by many molluscs - octopuses, squid, cuttlefish. For example, a scallop clam moves forward due to the reactive force of a stream of water ejected from the shell when its valves are sharply compressed.

Octopus

Cuttlefish

Cuttlefish, like most cephalopods, moves in water in the following way. It draws water into the gill cavity through the lateral slit and a special funnel in front of the body, and then vigorously throws out a stream of water through the funnel. The cuttlefish directs the funnel tube to the side or back and rapidly squeezing water out of it, can move in different directions.

Salpa is a sea animal with a transparent body, when it moves, it receives water through the front opening, and water enters a wide cavity, inside which the gills are stretched diagonally. As soon as the animal takes a long sip of water, the hole closes. Then the longitudinal and transverse muscles of the salpa contract, the whole body contracts, and water is pushed out through the posterior opening. The reaction of the flowing jet pushes the salpa forward.

Of greatest interest is the squid jet engine. The squid is the largest invertebrate inhabitant of the ocean depths. Squids have reached the highest perfection in jet navigation. In them, even the body with its external forms copies the rocket (or better to say - the rocket copies the squid, since it has an indisputable priority in this matter). When moving slowly, the squid uses a large diamond-shaped fin that bends periodically. He uses a jet engine for a quick throw. Muscle tissue - the mantle surrounds the body of the mollusk from all sides, the volume of its cavity is almost half the volume of the body of the squid. The animal sucks water into the mantle cavity, and then abruptly throws out a stream of water through a narrow nozzle and at high speed moves backwards in jerks. In this case, all ten tentacles of the squid gather in a knot above the head, and it acquires a streamlined shape. The nozzle is equipped with a special valve, and the muscles can turn it, changing the direction of movement. The squid engine is very economical, it is capable of speeds up to 60 - 70 km / h. (Some researchers believe that even up to 150 km / h!) No wonder the squid is called a “live torpedo”. Bending the tentacles folded in a bundle to the right, left, up or down, the squid turns in one direction or the other. Since such a rudder is very large in comparison with the animal itself, its slight movement is enough for the squid, even at full speed, to easily dodge a collision with an obstacle. A sharp turn of the steering wheel - and the swimmer rushes already in reverse side... So he bent the end of the funnel back and now slides head first. He bent it to the right - and a jet push threw him to the left. But when you need to swim fast, the funnel always sticks out right between the tentacles, and the squid rushes forward with its tail, as a crayfish would run - a runner endowed with the agility of a horse.

If there is no need to rush, squid and cuttlefish swim, undulating with fins - miniature waves run along them from front to back, and the animal glides gracefully, occasionally pushing itself also with a stream of water thrown out from under the mantle. Then the individual shocks that the mollusk receives at the time of the eruption of water jets are clearly visible. Some cephalopods can reach speeds of up to fifty-five kilometers per hour. It seems that no one has made direct measurements, but this can be judged by the speed and range of flying squid. And such, it turns out, there are talents in the relatives of the octopus! The best mollusk pilot is the stenoteutis squid. English sailors call it - flying squid ("flying squid"). It is a small herring-sized animal. He pursues fish with such swiftness that he often jumps out of the water, sweeping like an arrow over its surface. He resorts to this trick and saving his life from predators - tuna and mackerel. Having developed the maximum jet thrust in the water, the pilot squid takes off into the air and flies over the waves for more than fifty meters. The apogee of a live rocket's flight lies so high above the water that flying squids often land on the decks of ocean-going ships. Four to five meters is not a record height to which squid rise into the sky. Sometimes they fly even higher.

The English shellfish researcher Dr. Rees described in a scientific article a squid (only 16 centimeters long), which, having flown a fair distance through the air, fell on the yacht's bridge, which was almost seven meters above the water.

It happens that a lot of flying squids fall on the ship in a sparkling cascade. The ancient writer Trebius Niger once told a sad story about a ship that even sank under the weight of flying squids that fell on its deck. Squids can take off without acceleration.

Octopuses can fly too. French naturalist Jean Verany saw how an ordinary octopus accelerated in an aquarium and suddenly jumped out of the water backwards. After describing an arc five meters long in the air, he flopped back into the aquarium. Gathering speed to jump, the octopus moved not only due to jet thrust, but also rowed with tentacles.
Baggy octopuses swim, of course, worse than squids, but at critical moments they can show a record class for the best sprinters. Staff at the California Aquarium tried to photograph an octopus attacking a crab. The octopus rushed to its prey so quickly that there was always grease on the film, even when shooting at the highest speeds. So the throw lasted hundredths of a second! Usually octopuses swim relatively slowly. Joseph Seinle, who studied the migration of octopuses, calculated: an octopus half a meter in size floats on the sea with average speed about fifteen kilometers per hour. Each stream of water thrown out of the funnel pushes it forward (or rather, backward, since the octopus swims backwards) two to two and a half meters.

Jet propulsion can also be found in the plant world. For example, ripe fruits of "mad cucumber" at the slightest touch bounce off the stalk, and a sticky liquid with seeds is thrown out of the hole with force. At the same time, the cucumber itself flies off in the opposite direction up to 12 m.

Knowing the law of conservation of momentum, you can change your own speed of movement in open space. If you are in a boat and have several heavy stones, then by throwing stones in a certain direction, you will move in the opposite direction. The same will happen in outer space, but there they use jet engines for this.

Everyone knows that a shot from a gun is accompanied by a recoil. If the weight of the bullet were equal to the weight of the gun, they would fly at the same speed. Recoil occurs because the rejected mass of gases creates a reactive force, thanks to which movement can be ensured both in air and in airless space. And the greater the mass and velocity of the outflowing gases, the greater the recoil force our shoulder feels, the stronger the reaction of the gun, the greater the reactive force.

The use of jet propulsion in technology

For many centuries, humanity has dreamed of space travel. Science fiction writers have offered a variety of means to achieve this goal. In the 17th century, the story of the French writer Cyrano de Bergerac about the flight to the moon appeared. The hero of this story reached the moon in an iron cart, over which he constantly tossed a strong magnet. Pulling towards him, the wagon rose higher and higher above the Earth until it reached the moon. And Baron Munchausen said that he climbed to the moon on a bean stalk.

At the end of the first millennium AD, China invented jet propulsion, which propelled rockets - bamboo tubes filled with gunpowder, they were also used as fun. One of the first projects of cars was also with a jet engine and this project belonged to Newton.

The author of the world's first project of a jet aircraft designed for human flight was the Russian revolutionary N.I. Kibalchich. He was executed on April 3, 1881 for participating in the assassination attempt on Emperor Alexander II. He developed his project in prison after the death sentence. Kibalchich wrote: “While in prison, a few days before my death, I am writing this project. I believe in the feasibility of my idea, and this belief supports me in my terrible situation ... I will calmly face death, knowing that my idea will not perish with me. "

The idea of using rockets for space flights was proposed at the beginning of this century by the Russian scientist Konstantin Eduardovich Tsiolkovsky. In 1903, an article by the teacher of the Kaluga gymnasium K.E. Tsiolkovsky "Exploration of world spaces by jet devices". This work contained the most important mathematical equation for astronautics, now known as the "Tsiolkovsky formula", which described the motion of a body of variable mass. Subsequently, he developed a scheme for a liquid-fuel rocket engine, proposed a multistage rocket design, and expressed the idea of the possibility of creating entire space cities in near-earth orbit. He showed that the only device capable of overcoming the force of gravity is a rocket, i.e. apparatus with a jet engine using fuel and an oxidizer located on the apparatus itself.

A jet engine is an engine that converts the chemical energy of a fuel into the kinetic energy of a gas jet, while the engine gains speed in the opposite direction.

The idea of K.E. Tsiolkovsky was implemented by Soviet scientists under the leadership of Academician Sergei Pavlovich Korolev. The first ever artificial Earth satellite using a rocket was launched in the Soviet Union on October 4, 1957.

The principle of jet propulsion finds wide practical application in aviation and astronautics. In outer space, there is no medium with which the body could interact and thereby change the direction and modulus of its velocity, therefore, only jet aircraft, i.e. rockets, can be used for space flights.

Rocket device

The motion of the rocket is based on the law of conservation of momentum. If at some point in time any body is thrown away from the rocket, then it will acquire the same impulse, but directed in the opposite direction

In any rocket, regardless of its design, there is always a shell and fuel with an oxidizer. The rocket shell includes a payload (in this case, a spacecraft), an instrument compartment, and an engine (combustion chamber, pumps, etc.).

The bulk of the rocket is fuel with an oxidizer (an oxidizer is needed to maintain fuel combustion, since there is no oxygen in space).

Fuel and oxidizer are pumped into the combustion chamber. Fuel, burning, turns into gas of high temperature and high pressure... Due to the large pressure difference in the combustion chamber and in outer space, gases from the combustion chamber rush outward in a powerful jet through a specially shaped bell, called a nozzle. The purpose of the nozzle is to increase the speed of the jet.

Before the launch of the rocket, its impulse is zero. As a result of the interaction of the gas in the combustion chamber and all other parts of the rocket, the gas escaping through the nozzle receives a certain impulse. Then the rocket is a closed system, and its total impulse should be equal to zero even after launch. Therefore, the shell of the rocket completely, which is in it, receives an impulse equal in magnitude to the momentum of the gas, but opposite in direction.

The most massive part of the rocket, designed to launch and accelerate the entire rocket, is called the first stage. When the first massive stage of a multistage rocket runs out of fuel during acceleration, it is separated. Further acceleration is continued by the second, less massive stage, and to the speed previously achieved with the help of the first stage, it adds some more speed, and then separates. The third stage continues to increase the speed to the required value and delivers the payload to orbit.

The first person to fly in outer space was a citizen of the Soviet Union Yuri Alekseevich Gagarin. April 12, 1961 He circled the globe aboard the Vostok satellite

Soviet rockets were the first to reach the Moon, circled the Moon and photographed its invisible side from Earth, the first to reach the planet Venus and deliver scientific instruments to its surface. In 1986, two Soviet spacecraft "Vega-1" and "Vega-2" examined Halley's comet at close range, approaching the Sun once every 76 years.

The best case, to demand correction ... ”R. Feynman Even a brief review of the history of the development of technology shows a striking fact of the avalanche-like development of modern science and technology on the scale of the history of all mankind. If the transition of a person from stone tools to metal took about 2 million years; improvement of a wheel from a solid wood wheel to a wheel with a hub, ...

Which is lost in the depths of centuries, was, is and always will be the focus of national science and culture: and will always be open in the cultural and scientific movement to the whole World. "*" Moscow in the history of science and technology "- this is the name of the research project (leader S.S Ilizarov), carried out by the Vavilov Institute of the History of Natural Science and Technology of the Russian Academy of Sciences with the support of ...

The results of his many years of work in various fields of physical optics. It laid the foundations for a new direction in optics, which the scientist called micro-optics. Vavilov paid great attention to questions of the philosophy of natural science and the history of science. He is credited with developing, publishing and promoting the scientific heritage of M.V. Lomonosov, V.V. Petrov and L. Euler. The scientist headed the Commission on History ...

Reactive motion in nature and technology

ABSTRACT IN PHYSICS

Jet propulsion- the movement that occurs when some part of the body separates from the body at a certain speed.

Reactive force arises without any interaction with external bodies.

The use of jet propulsion in nature

Octopus

Cuttlefish

Of greatest interest is the squid jet engine. The squid is the largest invertebrate inhabitant of the ocean depths. Squids have reached the highest perfection in jet navigation. In them, even the body with its external forms copies the rocket (or better to say - the rocket copies the squid, since it has an indisputable priority in this matter). When moving slowly, the squid uses a large diamond-shaped fin that bends periodically. He uses a jet engine for a quick throw. Muscle tissue - the mantle surrounds the body of the mollusk from all sides, the volume of its cavity is almost half the volume of the body of the squid. The animal sucks water into the mantle cavity, and then abruptly throws out a stream of water through a narrow nozzle and at high speed moves backwards in jerks. In this case, all ten tentacles of the squid gather in a knot above the head, and it acquires a streamlined shape. The nozzle is equipped with a special valve, and the muscles can turn it, changing the direction of movement. The squid engine is very economical, it is capable of speeds up to 60 - 70 km / h. (Some researchers believe that even up to 150 km / h!) No wonder the squid is called a “live torpedo”. Bending the tentacles folded in a bundle to the right, left, up or down, the squid turns in one direction or the other. Since such a rudder is very large in comparison with the animal itself, its slight movement is enough for the squid, even at full speed, to easily dodge a collision with an obstacle. A sharp turn of the steering wheel - and the swimmer rushes in the opposite direction. So he bent the end of the funnel back and now slides head first. He bent it to the right - and a jet push threw him to the left. But when you need to swim fast, the funnel always sticks out right between the tentacles, and the squid rushes forward with its tail, as a crayfish would run - a runner endowed with the agility of a horse.

Octopuses can fly too. French naturalist Jean Verany saw how an ordinary octopus accelerated in an aquarium and suddenly jumped out of the water backwards. After describing an arc five meters long in the air, he flopped back into the aquarium. Gathering speed to jump, the octopus moved not only due to jet thrust, but also rowed with tentacles.
Baggy octopuses swim, of course, worse than squids, but at critical moments they can show a record class for the best sprinters. Staff at the California Aquarium tried to photograph an octopus attacking a crab. The octopus rushed to its prey so quickly that there was always grease on the film, even when shooting at the highest speeds. So the throw lasted hundredths of a second! Usually octopuses swim relatively slowly. Joseph Seinle, who studied the migration of octopuses, calculated that an octopus half a meter in size floats on the sea at an average speed of about fifteen kilometers per hour. Each stream of water thrown out of the funnel pushes it forward (or rather, backward, since the octopus swims backwards) two to two and a half meters.

The use of jet propulsion in technology

Jet engine Is an engine that converts the chemical energy of the fuel into the kinetic energy of a gas jet, while the engine acquires speed in the opposite direction.

Rocket device

The bulk of the rocket is fuel with an oxidizer (an oxidizer is needed to maintain fuel combustion, since there is no oxygen in space).

Fuel and oxidizer are pumped into the combustion chamber. Fuel, burning, turns into gas of high temperature and high pressure. Due to the large pressure difference in the combustion chamber and in outer space, gases from the combustion chamber rush outward in a powerful jet through a specially shaped bell, called a nozzle. The purpose of the nozzle is to increase the speed of the jet.

The first person to fly in outer space was a citizen of the Soviet Union Yuri Alekseevich Gagarin. April 12, 1961 He circled the globe aboard the Vostok satellite

Ministry of Education and Science of the Russian Federation
FGOU SPO "Perevozsky Construction College"
abstract
discipline:
Physics
theme: Jet propulsion

Completed:
Student
Groups 1-121
Okuneva Alena
Checked:
P.L. Vineaminovna

Perevoz town
2011
Content:

Introduction: what is Jet Propulsion ......................

Impulse conservation law ………………………………………………………………… .4

Application of jet propulsion in nature ………………………… ..….… .... 5

Application of jet propulsion in technology ……. ………………… ...… ..….… .6

Jet propulsion "Intercontinental missile" ………… .. ……… ...… 7

The physical foundations of a jet engine

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Classification of jet engines and features of their use ………………………………………………………………………. …………. …… .9

Features of the design and creation of an aircraft ... .. ... 10

Conclusion …………………………………………………………………………………………… .11

List of used literature ……………………………………………… ...

"Jet propulsion"
Reactive motion is the movement of a body due to the separation from it with a certain speed of some of its parts. Reactive motion is described based on the law of conservation of momentum.
Jet propulsion, which is now used in airplanes, rockets and space projectiles, is characteristic of octopuses, squid, cuttlefish, jellyfish - all of them, without exception, use the reaction (recoil) of the thrown jet of water for swimming.
Examples of jet propulsion can also be found in the plant world.
In southern countries, there is a plant called "mad cucumber". One has only to lightly touch the ripe fruit, similar to a cucumber, as it rebounds from the stalk, and through the hole formed from the fruit, a liquid with seeds flies out with a fountain at a speed of up to 10 m / s.

The cucumbers themselves fly off in the opposite direction. A mad cucumber (otherwise it is called a "lady's pistol") shoots more than 12 m.

"Law of conservation of momentum"
In a closed system, the vector sum of the impulses of all bodies included in the system remains constant for any interactions between the bodies of this system.
This fundamental law of nature is called the law of conservation of momentum. It is a consequence of Newton's second and third laws. Consider two interacting bodies that are part of a closed system.
The forces of interaction between these bodies will be denoted by and According to the third law of Newton If these bodies interact during time t, then the impulses of the forces of interaction are the same in magnitude and directed in opposite directions: Apply the second law of Newton to these bodies:

This equality means that as a result of the interaction of two bodies, their total momentum has not changed. Considering now all kinds of paired interactions of bodies included in a closed system, we can conclude that the internal forces of a closed system cannot change its total impulse, that is, the vector sum of the impulses of all bodies included in this system. A significant reduction in the launch mass of the rocket can be achieved by usingmulti-stage missileswhen the rocket stages separate as the fuel burns out. The process of the subsequent acceleration of the rocket excludes the masses of containers in which there was fuel, spent engines, control systems, etc. It is along the path of creating economical multistage rockets that modern rocketry is developing.

"The use of jet propulsion in nature"
Jet propulsion is used by many molluscs - octopuses, squid, cuttlefish. For example, a scallop clam moves forward due to the reactive force of a stream of water ejected from the shell when its valves are sharply compressed.

Octopus
Cuttlefish, like most cephalopods, moves in water in the following way. It draws water into the gill cavity through the lateral slit and a special funnel in front of the body, and then vigorously throws out a stream of water through the funnel. The cuttlefish directs the funnel tube to the side or back and rapidly squeezing water out of it, can move in different directions.
Salpa is a sea animal with a transparent body, when it moves, it receives water through the front opening, and water enters a wide cavity, inside which the gills are stretched diagonally. As soon as the animal takes a long sip of water, the hole closes. Then the longitudinal and transverse muscles of the salpa contract, the whole body contracts, and water is pushed out through the posterior opening. The reaction of the flowing jet pushes the salpa forward. Of greatest interest is the squid jet engine. The squid is the largest invertebrate inhabitant of the ocean depths. Squids have reached the highest perfection in jet navigation. Their bodies even copy the rocket with their external forms. Knowing the law of conservation of momentum, you can change your own speed of movement in open space. If you are in a boat and have several heavy stones, then by throwing stones in a certain direction, you will move in the opposite direction. The same will happen in outer space, but there they use jet engines for this.

"The use of jet propulsion in technology"
At the end of the first millennium AD, China invented jet propulsion, which propelled rockets - bamboo tubes filled with gunpowder, they were also used as fun. One of the first projects of cars was also with a jet engine and this project belonged to Newton.
The author of the world's first project of a jet aircraft designed for human flight was the Russian revolutionary N.I. Kibalchich. He was executed on April 3, 1881 for participating in the assassination attempt on Emperor Alexander II. He developed his project in prison after the death sentence. Kibalchich wrote: “While in prison, a few days before my death, I am writing this project. I believe in the feasibility of my idea, and this belief supports me in my terrible situation ... I will calmly face death, knowing that my idea will not perish with me. "
The idea of using rockets for space flights was proposed at the beginning of this century by the Russian scientist Konstantin Eduardovich Tsiolkovsky. In 1903, an article by the teacher of the Kaluga gymnasium K.E. Tsiolkovsky "Exploration of world spaces by jet devices". This work contained the most important mathematical equation for astronautics, now known as the "Tsiolkovsky formula", which described the motion of a body of variable mass. Subsequently, he developed a scheme for a liquid-fuel rocket engine, proposed a multistage rocket design, and expressed the idea of the possibility of creating entire space cities in near-earth orbit. He showed that the only device capable of overcoming the force of gravity is a rocket, i.e. apparatus with a jet engine using fuel and an oxidizer located on the apparatus itself. Soviet rockets were the first to reach the Moon, circled the Moon and photographed its invisible side from Earth, the first to reach the planet Venus and deliver scientific instruments to its surface. In 1986, two Soviet spacecraft "Vega-1" and "Vega-2" examined Halley's comet at close range, approaching the Sun once every 76 years.

Jet Propulsion "Intercontinental Rocket"
Humanity has always dreamed of traveling into space. Fiction writers, scientists, dreamers have proposed a variety of means to achieve this goal. But the only means at the disposal of man, with the help of which it is possible to overcome the force of gravity and fly into space for many centuries, has not been invented by any scientist, not a single science fiction writer. K.E. Tsiolkovsky - the founder of the theory of space flight.
For the first time, the dream and aspirations of many people were first brought closer to reality by the Russian scientist Konstantin Eduardovich Tsiolkovsky (1857-1935), who showed that the only apparatus capable of overcoming gravity is a rocket, he was the first to provide scientific proof of the possibility of using a rocket for flights into outer space , beyond the limits of the earth's atmosphere and to other planets of the solar system. Tsoilkovsky called a rocket an apparatus with a jet engine that uses fuel and an oxidizer on it.
As you know from the physics course, a shot from a gun is accompanied by a recoil. According to Newton's laws, a bullet and a gun would fly in different directions at the same speed if they had the same mass. The rejected mass of gases creates a reactive force, thanks to which movement can be ensured, both in air and in airless space, this is how recoil occurs. The greater the recoil force is felt by our shoulder, the greater the mass and velocity of the outflowing gases, and, consequently, the stronger the reaction of the gun, the greater the reactive force. These phenomena are explained by the law of conservation of momentum:
the vector (geometric) sum of the momenta of the bodies that make up a closed system remains constant for any motions and interactions of the bodies of the system.
The presented formula of Tsiolkovsky is the foundation on which the entire calculation of modern missiles is based. The Tsiolkovsky number is the ratio of the fuel mass to the rocket mass at the end of the engine operation - to the empty rocket weight.
Thus, we found that the maximum attainable speed of the rocket depends primarily on the speed of the outflow of gases from the nozzle. And the speed of the nozzle gas outflow, in turn, depends on the type of fuel and the temperature of the gas stream. This means that the higher the temperature, the greater the speed. Then, for a real rocket, you need to select the most high-calorie fuel that gives the greatest amount of heat. The formula shows that, among other things, the rocket speed depends on the initial and final mass of the rocket, on how much of its weight falls on the fuel, and how much on useless (in terms of flight speed) structures: body, mechanisms, etc. etc.
The main conclusion from this formula of Tsiolkovsky for determining the speed of a space rocket is that in an airless space the rocket will develop the greater speed, the greater the speed of the outflow of gases and the greater the number of Tsiolkovsky.

"Physical foundations of a jet engine"
Modern powerful jet engines of various types are based on the principle of direct reaction, i.e. the principle of creating a driving force (or thrust) in the form of a reaction (recoil) of a jet of "working substance" flowing out of the engine, usually incandescent gases. All motors have 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. After hot gases have formed in a heat engine, containing a large thermal energy, this energy must be converted into mechanical energy. After all, the engines serve to perform mechanical work, to "move" something, to put it into action, it doesn't matter whether it is a dynamo-machine on request to add drawings to a power plant, a diesel locomotive, a car or an airplane. In order for the thermal energy of gases to pass into mechanical energy, their volume must increase. With this expansion, the gases do the work, which consumes their internal and thermal energy.
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 velocity with which sound waves propagate in the outgoing gases, then the nozzle is a simple cylindrical or narrowing pipe segment. If the outflow velocity must exceed the speed of sound, then the nozzle is given the shape of an expanding pipe or, at first, narrowing, and then expanding (Lovely nozzle). Only in a pipe of this shape, as theory and experience show, can the gas be accelerated to supersonic speeds, and the "sound barrier" can be stepped over.

"Classification of jet engines and features of their use"
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 a 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 mighty crowns. This division was due to the fact that all "chemical" jet engines are divided into two classes, depending on whether they use the ambient air for their work or not.
In a non-compressor engine of another type, a ramjet, there is not even this valve lattice 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 the aircraft is already flying at a sufficiently high speed; it will not develop thrust in the parking lot. But on the other hand, at a very high speed, 4-5 times the speed of sound, a ramjet engine develops a very high thrust and consumes less fuel than any other "chemical" jet engine under these conditions. That's why ramjet engines.
etc.................

For most people, the term "jet propulsion" is presented in the form of modern progress in science and technology, especially in the field of physics. Many people associate jet propulsion in technology with spaceships, satellites and jet aircraft. It turns out that the phenomenon of jet propulsion existed much earlier than the person himself, and independently of him. People only managed to understand, use and develop what is subject to the laws of nature and the universe.

What is jet propulsion?

On English language the word "jet" sounds like "jet". It means the movement of a body, which is formed in the process of separating a part from it at a certain speed. A force appears that moves the body in the opposite direction from the direction of movement, separating a part from it. Each time the matter is pulled out of the object, and the object moves in the opposite direction, a jet motion is observed. In order to lift objects into the air, engineers must design a powerful rocket launcher. By releasing jets of flame, the rocket's engines lift it into Earth's orbit. Sometimes rockets launch satellites and space probes.

As for airliners and military aircraft, the principle of their operation is somewhat reminiscent of a rocket taking off: the physical body reacts to the ejected powerful jet of gas, as a result of which it moves in the opposite direction. This is the basic principle of jet aircraft.

Newton's laws in jet propulsion

Engineers base their developments on the principles of the universe, first described in detail in the works of the outstanding British scientist Isaac Newton, who lived at the end of the 17th century. Newton's laws describe the mechanisms of gravity and tell us what happens when things move. They are especially clear in explaining the movement of bodies in space.

Newton's second law determines that the force of a moving object depends on how much matter it contains, in other words, its mass and changes in the speed of movement (acceleration). This means that in order to create a powerful rocket, it is necessary that it constantly releases large amounts of high-speed energy. Newton's third law says that for every action there will be an equal in strength, but the opposite reaction - opposition. Jet engines in nature and technology obey these laws. In the case of a rocket, the force of action is matter that is ejected from the exhaust pipe. The countermeasure is to push the rocket forward. It is the force of the emissions from it that pushes the rocket. In space, where a rocket has practically no weight, even a small push from the rocket engines can make a large ship fly forward quickly.

Technique using jet propulsion

The physics of jet propulsion is that the acceleration or deceleration of a body occurs without the influence of surrounding bodies. The process occurs due to the separation of a part of the system.

Examples of jet propulsion in technology are:

the phenomenon of recoil from a shot;
explosions;
blows during accidents;
recoil when using a powerful fire hose;
a boat with a water-jet engine;
jet plane and rocket.

Bodies create a closed system if they only interact with each other. Such interaction can lead to a change in the mechanical state of the bodies that form the system.

What is the action of the law of conservation of momentum?

For the first time this law was announced by the French philosopher and physicist R. Descartes. When two or more bodies interact, a closed system is formed between them. Any body in motion has its own impulse. This is the mass of the body multiplied by its speed. The total impulse of the system is equal to the vector sum of the impulses of the bodies in it. The momentum of any of the bodies inside the system changes due to their mutual influence. The total momentum of bodies in a closed system remains unchanged for various displacements and interactions of bodies. This is the law of conservation of momentum.

Examples of the operation of this law can be any collisions of bodies (billiard balls, cars, elementary particles), as well as bursting of bodies and shooting. When a weapon is fired, a recoil occurs: the projectile rushes forward, and the weapon itself is pushed back. Why is this happening? The bullet and the weapon form a closed system with each other, where the law of conservation of momentum works. When firing, the impulses of the weapon itself and the bullet change. But the total impulse of the weapon and the bullet in it before firing will be equal to the total impulse of the rolling weapon and the bullet fired after firing. If the bullet and the gun had the same mass, they would fly in opposite directions at the same speed.

The momentum conservation law has a wide practical application. It allows you to explain the jet motion, due to which highest speeds.

Reactive motion in physics

The most striking example of the law of conservation of momentum is the jet propulsion carried out by a rocket. The most important part of the engine is the combustion chamber. In one of its walls there is a jet nozzle adapted for the release of gas arising from the combustion of fuel. Under the influence of high temperature and pressure, the gas exits the engine nozzle at high speed. Before the launch of the rocket, its momentum relative to the Earth is equal to zero. At the moment of launch, the rocket also receives an impulse, which is equal to the impulse of the gas, but in the opposite direction.

An example of the physics of jet propulsion can be seen everywhere. When celebrating a birthday, a balloon may well become a rocket. How? Inflate the balloon while pinching the open hole to keep air from escaping. Now let go of it. The balloon will be driven around the room at great speed, driven by the air escaping from it.

History of jet propulsion

The history of jet engines began as early as 120 years BC, when Heron of Alexandria designed the first jet engine - eolipil. Water is poured into a metal ball, which is heated by fire. The steam that escapes from this ball rotates it. This device shows jet propulsion. The priests successfully used the Heron's engine to open and close the doors of the temple. Modification of eolipil - Segner wheel, which is effectively used in our time for irrigation of agricultural land. In the 16th century, Giovani Branca introduced the world to the first steam turbine that worked on the principle of jet propulsion. Isaac Newton proposed one of the first designs for a steam car.

The first attempts to use jet propulsion in technology for moving on the ground date back to the 15-17 centuries. Even 1000 years ago, the Chinese had missiles that they used as military weapons. For example, in 1232, according to the chronicle, in the war with the Mongols, they used arrows equipped with missiles.

The first attempts to build a jet aircraft began in 1910. The rocket research of the past centuries was taken as a basis, which described in detail the use of powder boosters, which could significantly reduce the length of the afterburner and takeoff run. The chief designer was the Romanian engineer Anri Coanda, who built an aircraft based on a piston engine. The pioneer of jet propulsion in technology can rightfully be called an engineer from England - Frank Wheatle, who proposed the first ideas for creating a jet engine and received his patent for them at the end of the 19th century.

First jet engines

For the first time, the development of a jet engine in Russia was started at the beginning of the 20th century. The theory of motion of jet vehicles and rocketry capable of developing supersonic speed was put forward by the famous Russian scientist K.E. Tsiolkovsky. The talented designer A.M. Lyulka managed to bring this idea to life. It was he who created the project of the first jet aircraft in the USSR, working with a jet turbine. The first jet aircraft were created by German engineers. Project creation and production were carried out in secret in disguised factories. Hitler, with his idea of becoming a world ruler, involved the best designers in Germany to produce the most powerful weapons, including high-speed aircraft. The most successful of these was the first German jet, the Messerschmitt-262. This aircraft became the first in the world that successfully passed all the tests, took off freely and after that began to be mass-produced.

The aircraft had the following features:

The device had two turbojet engines.
A radar was located in the bow.
The aircraft's maximum speed reached 900 km / h.

Thanks to all these indicators and design features, the first jet aircraft "Messerschmitt-262" was a formidable weapon against other aircraft.

Prototypes of modern airliners

In the post-war period, Russian designers created jet aircraft, which later became the prototypes of modern airliners.

I-250, better known as the legendary MiG-13, is a fighter that A.I. Mikoyan worked on. The first flight took place in the spring of 1945, at that time the jet fighter showed a record speed of 820 km / h. The MiG-9 and Yak-15 jet aircraft were put into production.

In April 1945, for the first time, the jet aircraft of P.O. Sukhoi - Su-5 took off into the sky, rising and flying at the expense of an air-jet motor-compressor and piston engine located in the tail of the structure.

After the end of the war and the surrender of Nazi Germany, the Soviet Union got the German planes with jet engines JUMO-004 and BMW-003 as trophies.

First world prototypes

Not only German and Soviet designers were involved in the development, testing and production of new airliners. Engineers from the USA, Italy, Japan, Great Britain have also created many successful projects using jet propulsion in technology. The first developments with various types of engines include:

Non-178 is a German turbojet-powered aircraft that took off in August 1939.
GlosterE. 28/39 is an aircraft originally from Great Britain, with a turbojet engine, it first took to the skies in 1941.
He-176 - a fighter created in Germany using a rocket engine, made its first flight in July 1939.
BI-2 - the first Soviet aircraft, which was propelled by a missile power plant.
CampiniN.1 is a jet aircraft created in Italy, which was the first attempt by Italian designers to move away from the piston analogue.
Yokosuka MXY7 Ohka ("Oka") with a Tsu-11 engine is a Japanese fighter-bomber, the so-called disposable aircraft with a kamikaze pilot on board.

The use of jet propulsion in technology served as a sharp impetus for the rapid creation of the following jet aircraft and further development military and civil aircraft construction.

GlosterMeteor - a jet fighter, manufactured in Great Britain in 1943, played a significant role in the Second World War, and after its completion it served as an interceptor of German V-1 missiles.
The Lockheed F-80 is a US-made jet aircraft using an AllisonJ engine. These aircraft took part in the Japanese-Korean War more than once.
The B-45 Tornado is a prototype of the modern American B-52 bombers, created in 1947.
The MiG-15 is a follower of the recognized MiG-9 jet fighter, which actively participated in the military conflict in Korea, was produced in December 1947.
Tu-144 is the first Soviet supersonic jet passenger aircraft.

Modern jet vehicles

Every year, airliners are improving, because designers from all over the world are working to create a new generation of aircraft capable of flying at the speed of sound and at supersonic speeds. Now there are airliners capable of accommodating a large number of passengers and cargo, of enormous size and an unimaginable speed of over 3000 km / h, military aircraft equipped with modern combat gear.

But among this variety, there are several designs of record-breaking jet aircraft:

The Airbus A380 is the largest aircraft capable of accommodating 853 passengers on board, which is ensured by a double-deck structure. He is also one of the most luxurious and expensive airliners of our time. The largest passenger liner in the air.
Boeing 747 - for more than 35 years it was considered the most capacious double-decker airliner and could carry 524 passengers.
AN-225 Mriya is a cargo aircraft that boasts a carrying capacity of 250 tons.
LockheedSR-71 is a jet aircraft that reaches a speed of 3529 km / h during flight.

Aviation research does not stand still, because jet aircraft are the basis of the rapidly developing modern aviation. Several Western and Russian manned, passenger, unmanned jet-powered airliners are currently under design, and are scheduled to be released in the next few years.

Russian innovative developments of the future include the 5th generation PAK FA - T-50 fighter, the first copies of which will arrive at the troops presumably in late 2017 or early 2018 after testing a new jet engine.

Nature is an example of jet propulsion

The reactive principle of movement was originally prompted by nature itself. Its action is used by the larvae of some species of dragonflies, jellyfish, many mollusks - scallops, cuttlefish, octopuses, squids. They use a kind of "repulsion principle". Cuttlefish suck in water and throw it out so quickly that they themselves make a leap forward. Squids using this method can reach speeds of up to 70 kilometers per hour. That is why this method of movement made it possible to call squid "biological rockets". Engineers have already invented an engine based on the movement of a squid. One example of the use of jet propulsion in nature and technology is a water cannon.

This is a device that provides movement using the force of water thrown out under a strong pressure. In the device, water is pumped into the chamber, and then discharged from it through the nozzle, and the vessel moves in the opposite direction of the jet ejection. The water is drawn in with a diesel or gasoline engine.

The plant world also offers examples of jet propulsion. Among them there are species that use this movement to spread seeds, such as the mad cucumber. Only outwardly, this plant is similar to the cucumbers we are used to. And the characteristic "rabid" it received because of the strange way of reproduction. Ripening, the fruits bounce off the stalks. As a result, a hole opens through which the cucumber shoots a substance containing seeds suitable for germination, applying reactivity. And the cucumber itself bounces up to twelve meters to the side opposite to the shot.

The manifestation of jet propulsion in nature and technology is subject to the same laws of the universe. Mankind is increasingly using these laws to achieve its goals not only in the atmosphere of the Earth, but also in the vastness of space, and jet propulsion is a prime example of this.