Jet propulsion in nature briefly. A technique using jet propulsion. What is jet propulsion

Nomination "The world around us"

Preparing for the New Year celebration, I decorated the apartment with balloons. When I was inflating the balloons, one of them escaped from my hands and flew away from me in the opposite direction at high speed. I asked myself the question: what happened to the ball? The parents explained that this was a reactive movement. Does the ball really fly the same way as a rocket?

Hypothesis, which I put forward during the research: perhaps jet propulsion occurs in nature and everyday life.

Goals works:

study the physical principles of jet propulsion
identify where jet motion occurs in nature and everyday life.

To confirm or refute my hypothesis, I set myself tasks:

conduct experiments illustrating jet propulsion,
read popular science literature about jet propulsion,
find relevant materials on the Internet,
create a presentation on this topic.

HISTORICAL BACKGROUND

Jet propulsion was used in the manufacture of the first gunpowder fireworks and signal rockets in China in the 19th century. IN late XVIII centuries, Indian troops in the fight against the British colonialists used military rockets using black smoky powder. In Russia, powder rockets were adopted in early XIX century.

During the Great Patriotic War German troops used V-2 ballistic missiles, shelling English and Belgian cities. Soviet troops Katyusha multiple rocket launchers were used with great success.

Progenitors of jet engines:

Greek mathematician and mechanic Heron of Alexandria (Appendix 2.1), creator of the aeolipile (Heron's ball);
Hungarian scientist Janos Segner (Appendix 2.3), who created the “Segner wheel”;
N.I. Kibalchich was the first to propose the use of jet propulsion for space flights;
Further theoretical development rocket navigation belongs to the Russian scientist K.E. Tsiolkovsky.
His works inspired S.P. Korolev to create aircraft for human flight into space. Thanks to his ideas, for the first time in the world, the launch of an artificial Earth satellite was carried out (10/04/57) and the first manned satellite with a pilot-cosmonaut on board Yu.A. Gagarin (April 12, 1961).

PHYSICAL PRINCIPLES JET TRAFFIC AND ROCKET DEVICE

Reactive motion is based on the principle of action and reaction: if one body acts on another, then exactly the same force will act on it, but directed in the opposite direction.

I conducted an experiment that proves that for every action there is an equal reaction. (video clip)

A modern space rocket is a very complex and heavy aircraft, consisting of hundreds of thousands and millions of parts. It consists of 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 "dry" the mass of the rocket remaining after the release of hot gases from the rocket (this is the shell of the rocket, i.e. the astronauts’ life support systems, equipment, etc.). To achieve cosmic speeds, multi-stage rockets are used. When a jet gas jet is ejected from a rocket, the rocket itself rushes in the opposite direction, accelerating to 1st escape velocity: 8 km/s.

I conducted an experiment on the interaction of carts and proved that the greater the mass of fuel, the greater the speed the rocket acquires. This means that space travel requires a huge amount of fuel.

JET MOTION IN NATURE

So, where does jet motion occur in nature? Fish swim, birds fly, animals run. Everything seems to be simple. No matter how it is. The wanderlust of animals is not a whim, but a severe necessity. If you want to eat, know how to move. If you don't want to get eaten, know how to sneak away. To move quickly in space, you need to develop high speeds.

For this, for example, scallop- got a jet engine. It energetically throws water out of its shell and flies a distance that is 10-20 times its own length! Salpa, dragonfly larvae, fish- they all use the principle of jet propulsion to move in space. Octopus reaches speeds of up to 50 km/h and this is thanks to jet propulsion. He can even walk on land, because... He has a supply of water in his bosom for this case. Squid- the largest invertebrate inhabitant of the ocean depths moves according to the principle of jet propulsion.

Examples of jet propulsion can also be found in the plant world. In southern countries (and here on the Black Sea coast too) there grows a plant called "squirting cucumber"One has only to lightly touch a ripe fruit, similar to a cucumber, as it bounces off the stalk, and through the resulting hole, liquid with seeds flies out of the fruit like a fountain at a speed of up to 10 m/s. The cucumbers themselves fly off in the opposite direction. Shoots madly cucumber (otherwise called “ladies’ pistol”) more than 12 m.

In everyday life as an example soul on flexible hose You can see the manifestation of jet propulsion. As soon as you throw water into the shower, the handle with a sprayer at the end will deviate in the direction opposite to the flowing streams.

The operation of sprinkler systems (Appendix 7.2) for watering plantings in gardens and vegetable gardens is based on the principle of jet propulsion. The water pressure rotates the head with water sprays.

The principle of jet propulsion helps movement swimmer. The more a swimmer pushes the water back, the faster he swims. (Appendix 7.3)

Engineers have already created an engine similar to the squid engine. It is called a water cannon. (Appendix 7.4)

CONCLUSION

During work:

1. I found out that the principle of jet propulsion is the physical law of action and reaction

2. Experimentally confirmed the dependence of the speed of movement of a body on the mass of another body acting on it.

3. I was convinced that jet motion is found in technology, everyday life and nature, and even cartoons.

4. Now, knowing about jet propulsion, I can avoid many troubles, such as jumping from a boat to the shore, shooting a gun, including taking a shower, etc.

So I can say that hypothesis, what I put forward was confirmed: the principle of jet propulsion is very common in nature and everyday life.

LITERATURE

A book for reading on physics for grades 6-7. I.G. Kirillova, - M: Prosveshchenie, 1978. -97-99s
Physics - for young people extracurricular reading 7th grade. M.N. Alekseeva,-M: Education, 1980.- 113 p.
Hello, physics. L.Ya. Galpershtein, - M: Children's literature, 1967. - 39-41s
Encyclopedia Science. A. Craig, K. Rosny, - M: Rosman, 1997. - 29 p.
Hello octopus. Magazine "Misha", 1995, No. 8, 12-13c
Legs, wings and even...a jet engine. Magazine "Misha", 1995, No. 8, 14 p.
Wikipedia: -ru.wikipedia.org

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.

Flares are bullets compressed from a substance that burns with a colored flame.

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 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 stream. 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.

Fireworks using Chinese rockets

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.

The octopus is a sea creature that uses jet propulsion

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 the help 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 a 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, 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 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.

Jet boat - self-propelled vessel with a jet engine

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 is 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 steamship 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 rifts; 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 they crippled the artillery gunners 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.

Shooting with firearms

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 was connected to a compressor piston, which moves in its cylinder in the same way as a steam engine piston. 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 occurs, 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 end of the barrel and serves as its continuation. Its diameter is larger than the diameter of the barrel, and therefore it does not in the least interfere with the projectile flying out of the barrel. Several oblong holes are cut around the circumference of the tube walls.

Muzzle brake - reduces firearm recoil

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 path. 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 stream 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 a composition for a colored 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. The German fascists prepared and unleashed a bloody world war.

Missile

The shortcomings in the manufacture 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.

Missile

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”.

Spacecraft

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 into the sky on trained swans, in hot air 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 globe and the vehicle for this will be a rocket, 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, 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 desired speed, suitable 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 oxidizer. 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.

Jet propulsion in nature and technology

ABSTRACT ON PHYSICS

Jet propulsion- movement that occurs when any part of it is separated from the body at a certain speed.

Reactive force occurs without any interaction with external bodies.

Application of jet propulsion in nature

Many of us in our lives have encountered 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 also use jet propulsion to move. In addition, this is how dragonfly larvae and some types of marine plankton move. And often the efficiency of marine invertebrate animals when using jet propulsion is much higher than that of technological inventions.

Jet propulsion is used by many mollusks - octopuses, squids, cuttlefish. For example, a sea scallop mollusk moves forward due to the reactive force of a stream of water thrown out of the shell during a sharp compression of its valves.

Octopus

Cuttlefish

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

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

The squid's jet engine is of greatest interest. The squid is the largest invertebrate inhabitant of the ocean depths. Squids have achieved the highest perfection in jet navigation. Even their body, with its external forms, copies the rocket (or better said, the rocket copies the squid, since it has indisputable priority in this matter). When moving slowly, the squid uses a large diamond-shaped fin that periodically bends. It uses a jet engine to throw quickly. Muscle tissue - the mantle surrounds the mollusk's body on all sides; the volume of its cavity is almost half the volume of the squid's body. The animal sucks water inside the mantle cavity, and then sharply throws out a stream of water through a narrow nozzle and moves backwards with high speed pushes. At the same time, all ten tentacles of the squid are gathered into a knot above its head, and it takes on a streamlined shape. The nozzle is equipped with a special valve, and the muscles can rotate it, changing the direction of movement. The squid's engine is very economical, it is capable of reaching speeds of up to 60 - 70 km/h. (Some researchers believe that even up to 150 km/h!) No wonder the squid is called a “living torpedo.” By bending the bundled tentacles to the right, left, up or down, the squid turns in one direction or another. Since such a steering wheel, compared to the animal itself, has a very large sizes, then its slight movement is enough for the squid, even at full speed ahead, could easily dodge a collision with an obstacle. A sharp turn of the steering wheel - and the swimmer rushes into reverse side. So he bent the end of the funnel back and now slides head first. He bent it to the right - and the jet push threw him to the left. But when you need to swim quickly, the funnel always sticks out right between the tentacles, and the squid rushes tail first, just as a crayfish would run - a fast walker endowed with the agility of a horse.

If there is no need to rush, squids and cuttlefish swim with undulating fins - miniature waves run over 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 moment of 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 flight range of flying squids. And it turns out that octopuses have such talents in their family! The best pilot among mollusks is the squid Stenoteuthis. English sailors call it flying squid (“flying squid”). This is a small animal about the size of a herring. It chases fish with such speed that it often jumps out of the water, skimming over its surface like an arrow. He resorts to this trick to save his life from predators - tuna and mackerel. Having developed 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 living rocket's flight lies so high above the water that flying squids often end up on the decks of ocean-going ships. Four to five meters is not a record height to which squids rise into the sky. Sometimes they fly even higher.

The English mollusk researcher Dr. Rees described in scientific article a squid (only 16 centimeters long), which, having flown a considerable distance through the air, fell onto the bridge of the yacht, which rose 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 sad story about a ship that allegedly even sank under the weight of flying squids that fell on its deck. Squids can take off without acceleration.

Octopuses can also fly. French naturalist Jean Verani saw how an ordinary octopus accelerated in an aquarium and suddenly jumped out of the water backwards. Having described an arc about five meters long in the air, he plopped back into the aquarium. When picking up speed to jump, the octopus moved not only due to jet thrust, but also rowed with its tentacles.
Baggy octopuses swim, of course, worse than squids, but at critical moments they can show a record class for the best sprinters. California Aquarium staff tried to photograph an octopus attacking a crab. The octopus rushed at its prey with such speed that the film, even when filming at the highest speeds, always contained grease. This means that the throw lasted hundredths of a second! Typically, octopuses swim relatively slowly. Joseph Seinl, who studied the migrations of octopuses, calculated: an octopus half a meter in size swims through the sea at an average speed of about fifteen kilometers per hour. Each jet 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 motion can also be found in the plant world. For example, the ripe fruits of the “mad cucumber”, with the slightest touch, bounce off the stalk, and a sticky liquid with seeds is forcefully thrown out of the resulting hole. 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 you have several heavy stones, then throwing stones in a certain direction will move you 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 recoil. If the weight of the bullet were equal to the weight of the gun, they would fly apart at the same speed. Recoil occurs because the ejected 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 speed of the flowing gases, the greater the recoil force our shoulder feels, the stronger the reaction of the gun, the greater the reactive force.

Application of jet propulsion in technology

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

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

The author of the world's first project of a jet aircraft intended for human flight was the Russian revolutionary N.I. Kibalchich. He was executed on April 3, 1881 for his participation in the assassination attempt on Emperor Alexander II. He developed his project in prison after being sentenced to death. 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 faith supports me in my terrible situation... I will calmly face death, knowing that my idea will not die 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 Kaluga gymnasium teacher K.E. appeared in print. Tsiolkovsky “Exploration of world spaces using reactive instruments.” 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 design for a liquid-fuel rocket engine, proposed a multi-stage rocket design, and expressed the idea of the possibility of creating entire space cities in low-Earth orbit. He showed that the only device capable of overcoming gravity is a rocket, i.e. a device with a jet engine that uses fuel and oxidizer located on the device itself.

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

What is jet propulsion?

On English the word "reactive" 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. Every time matter is ejected from an object and the object moves in the opposite direction, jet motion is observed. To lift objects into the air, engineers must design a powerful rocket launcher. 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: physical body reacts to a powerful jet of gas ejected, as a result of which it moves in the opposite direction. This is the basic operating principle of jet aircraft.

Newton's laws of jet propulsion

Engineers base their developments on the principles of the structure 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 objects move. They explain especially clearly the movement of bodies in space.

Newton's second law states that the force of a moving object depends on how much matter it contains, in other words, its mass and the change in speed of motion (acceleration). This means that in order to create a powerful rocket, it is necessary for it to constantly release large number high speed energy. Newton's third law states that for every action there will be an equal but opposite reaction - a reaction. Jet engines in nature and technology obey these laws. In the case of a rocket, the force is the matter that comes out of the exhaust pipe. The reaction 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 virtually no weight, even a small push from the rocket engines can send a large ship flying forward quickly.

Technique using jet propulsion

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

Examples of jet propulsion in technology are:

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

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

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

This law was first announced by the French philosopher and physicist R. Descartes. When two or more bodies interact, a closed system is formed between them. When moving, any body has its own momentum. This is the mass of a body multiplied by its speed. The total momentum of the system is equal to the vector sum of the momenta of the bodies located 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 under various movements and interactions of bodies. This is the law of conservation of momentum.

Examples of the action of this law can be any collisions of bodies (billiard balls, cars, elementary particles), as well as ruptures of bodies and shooting. When a weapon is fired, 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 between themselves, 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 recoiling weapon and the fired bullet after firing. If the bullet and the gun had the same mass, they would fly in opposite directions at the same speed.

The law of conservation of momentum has a wide range of practical application. It allows us to explain the jet motion, thanks to which the highest speeds are achieved.

Jet propulsion in physics

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

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

History of jet propulsion

The history of jet engines dates back to 120 years BC, when Heron of Alexandria designed the first jet engine, the aeolipile. Water is poured into a metal ball and heated by fire. The steam that escapes from this ball rotates it. This device shows jet propulsion. The priests successfully used Heron's engine to open and close temple doors. A modification of the aeolipile is the Segner wheel, which is effectively used in our time for watering agricultural land. In the 16th century, Giovani Branca introduced the world to the first steam turbine, which operated 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 land date back to the 15-17 centuries. Even 1000 years ago, the Chinese had rockets 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 rockets.

The first attempts to build a jet aircraft began in 1910. The basis was taken from rocket research of past centuries, which described in detail the use of powder accelerators that could significantly reduce the length of the afterburner and take-off run. The chief designer was the Romanian engineer Henri Coanda, who built an aircraft powered by a piston engine. The pioneer of jet propulsion in technology can rightfully be called an engineer from England - Frank Whittle, who proposed the first ideas for creating a jet engine and received his patent for them in late XIX century.

The first jet engines

The development of a jet engine in Russia first began at the beginning of the 20th century. The theory of the movement of jet vehicles and rocketry capable of reaching 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 for the first jet aircraft in the USSR, powered by a jet turbine. The first jet aircraft were created by German engineers. Project creation and production were carried out secretly in disguised factories. Hitler, with his idea of becoming a world ruler, hired the best designers in Germany for production the most powerful weapon, including high-speed aircraft. The most successful of these was the first German jet aircraft, the Messerschmitt 262. This aircraft became the first in the world to successfully pass all the tests, take off freely and then begin to be mass-produced.

The aircraft had the following features:

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

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

Prototypes of modern airliners

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

The I-250, better known as the legendary MiG-13, is a fighter that A. I. Mikoyan worked on. The first flight was made 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, P. O. Sukhoi's Su-5 jet aircraft took to the skies for the first time, rising and flying due to an air-breathing motor-compressor and piston engine located in the rear part of the structure.

After the end of the war and the surrender of Nazi Germany Soviet Union German aircraft with jet engines JUMO-004 and BMW-003 were taken as trophies.

First world prototypes

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

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

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

GlosterMeteor - air-breathing fighter, manufactured in Great Britain in 1943, played significant role in the Second World War, and after its completion he carried out the task of intercepting German V-1 missiles.
The Lockheed F-80 is a jet aircraft manufactured in the USA using an AllisonJ engine. These aircraft took part more than once in the Japanese-Korean War.
The B-45 Tornado is a prototype of the modern American B-52 bomber, created in 1947.
The MiG-15, a successor to the acclaimed 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 air-jet passenger aircraft.

Modern jet vehicles

Airliners are improving every year, as 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 that can accommodate a large number of passengers and cargo, have enormous sizes and unimaginable speeds of over 3000 km/h, and military aircraft equipped with modern combat equipment.

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

The Airbus A380 is the most spacious aircraft, capable of accommodating 853 passengers, which is ensured by its double-deck design. It is also one of the most luxurious and expensive airliners of our time. The largest passenger airliner in the air.
Boeing 747 - for more than 35 years was considered the most spacious double-decker airliner and could carry 524 passengers.
The AN-225 Mriya is a cargo aircraft that boasts a payload 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 rapidly developing modern aviation. Currently, several Western and Russian manned, passenger, and unmanned airliners with jet engines are being designed, the release of which is planned for the next few years.

Russian innovative developments of the future include the 5th generation fighter PAK FA - T-50, the first copies of which will presumably enter service at the end of 2017 or the beginning of 2018 after testing a new jet engine.

Nature is an example of jet propulsion

The reactive principle of movement was initially suggested by nature itself. Its effect is used by the larvae of some types of dragonflies, jellyfish, and many mollusks - scallops, cuttlefish, octopuses, and squid. They apply a kind of “repulsion principle”. Cuttlefish draw 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 squids “biological rockets.” Engineers have already invented an engine that works on the principle of squid movements. 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 strong pressure. In the device, water is pumped into the chamber and then released from it through a nozzle, and the vessel moves in the opposite direction to the jet emission. Water is drawn in using an engine running on diesel or gasoline.

The plant world also offers us examples of jet propulsion. Among them there are species that use such movement to disperse seeds, for example, the mad cucumber. Only externally this plant is similar to the cucumbers we are used to. And it received the characteristic “mad” because of its strange method of reproduction. When ripe, the fruits bounce off the stalks. Eventually, a hole opens through which the cucumber shoots a substance containing seeds suitable for germination using reactivity. And the cucumber itself bounces up to twelve meters in the direction opposite to the shot.

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

Jet propulsion- movement that occurs when any part of it is separated from the body at a certain speed.

Reactive force occurs without any interaction with external bodies.

Application of jet propulsion in nature

Many of us in our lives have encountered jellyfish while swimming in the sea. In any case, there are quite enough of them in the Black Sea. But few people are for

I thought that jellyfish also use jet propulsion to move. In addition, this is how dragonfly larvae and some types of marine plankton move. And often the efficiency of marine invertebrate animals when using jet propulsion is much higher than that of technological inventions.

Octopus

Cuttlefish

The squid's jet engine is of greatest interest. The squid is the largest invertebrate inhabitant of the ocean depths. Squids have achieved the highest perfection in jet navigation. Even their body, with its external forms, copies the rocket (or better said, the rocket copies the squid, since it has indisputable priority in this matter). When moving slowly, the squid uses a large diamond-shaped fin that periodically bends. It uses a jet engine to throw quickly. Muscle tissue - the mantle surrounds the mollusk's body on all sides; the volume of its cavity is almost half the volume of the squid's body. The animal sucks water inside the mantle cavity, and then sharply throws out a stream of water through a narrow nozzle and moves backwards with high speed pushes. At the same time, all ten tentacles of the squid are gathered into a knot above its head, and it takes on a streamlined shape. The nozzle is equipped with a special valve, and the muscles can rotate it, changing the direction of movement. The squid's engine is very economical, it is capable of reaching speeds of up to 60 - 70 km/h. (Some researchers believe that even up to 150 km/h!) No wonder the squid is called a “living torpedo.” By bending the bundled tentacles to the right, left, up or down, the squid turns in one direction or another. Since such a steering wheel is very large compared to 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 the jet push threw him to the left. But when you need to swim quickly, the funnel always sticks out right between the tentacles, and the squid rushes tail first, just as a crayfish would run - a fast walker endowed with the agility of a horse.

The English mollusk 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 bridge of a yacht, which rose 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 allegedly sank under the weight of flying squids that fell on its deck. Squids can take off without acceleration.

Octopuses can also fly. French naturalist Jean Verani saw how an ordinary octopus accelerated in an aquarium and suddenly jumped out of the water backwards. Having described an arc about five meters long in the air, he plopped back into the aquarium. When picking up speed to jump, the octopus moved not only due to jet thrust, but also rowed with its tentacles. Baggy octopuses swim, of course, worse than squids, but at critical moments they can show a record class for the best sprinters. California Aquarium staff tried to photograph an octopus attacking a crab. The octopus rushed at its prey with such speed that the film, even when filming at the highest speeds, always contained grease. This means that the throw lasted hundredths of a second! Typically, octopuses swim relatively slowly. Joseph Seinl, who studied the migrations of octopuses, calculated: an octopus half a meter in size swims through the sea at an average speed of about fifteen kilometers per hour. Each jet 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.