Abstract on physics on the topic: “Jet propulsion. Rockets. Jet propulsion

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

Story

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

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

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

Vegetable world

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

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

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

Animal world

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

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

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

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

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

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

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

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

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

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, famous French physicist Marcel Depres stated:

But you know, Newton's laws are not entirely true. The body can move with the help of internal forces, without relying on anything or pushing away from anything.

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

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

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

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

The same movements, without interaction with any foreign object, can 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 when Living being changes its movement in the air for no apparent reason.

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

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

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

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

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 any way 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 jet of gases hits not forward, but backward, creating a forward-directed reaction in the projectile.

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

In its design, a rocket projectile is similar to a fireworks rocket, it is only larger in size. In its head part, instead of 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 maybe even older than it: o combat use rockets reported by ancient Chinese and Arabic books written over a thousand years ago.

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

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”.

Spaceship

For many centuries, people have cherished the dream of flying in interplanetary space, of visiting the Moon, mysterious Mars and cloudy Venus. Many science fiction novels, novellas and short stories have been written on this topic. Writers sent their heroes to the sky on trained swans, 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 idea space travel . He proved that people can leave Earth And vehicle a rocket will serve for this, because a rocket is the only engine that does not need any external support for its movement. That's why rocket capable of flying in airless space.

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

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

Introduction………………………………………………………………………………….3

1. K.E. Tsiolkovsky – founder of the theory of space flight………..4

2. Jet engine………………………………………………………..5

3. The design of a ballistic missile………………………………………………………7

3.1. Ballistic missile engine…………………………………………..8

3.2. Pumps…………………………………………………………………………………9

3.4. Alternative to gas rudders………………………………………………………..10

4. Launch pad……………………………………………………………..11

5. Flight path……………………………………………………………..12

6 . Conclusion………………………………………………………………………………13

7. List of used literature:…………………………………….14

8. Evaluation sheet.……………………………………………………………..15

Introduction

I, a student of grade 9 “B”, Dmitry Vyacheslavovich Egorov, present to you my essay on the topic: “Jet propulsion. Rockets." I believe that humanity has always dreamed of traveling into space. The most different means To achieve this goal, writers - science fiction writers, scientists, dreamers - proposed. But for many centuries, not a single scientist or science fiction writer has been able to invent the only means at a person’s disposal with which one can overcome the force of gravity and fly into space. For example, the hero of the story French writer Cyrano de Bergerac, written in the 17th century, reached the moon by throwing a strong magnet over an iron cart in which he was sitting. The carriage rose higher and higher above the Earth, attracted to the magnet, until it reached the Moon; Baron Munchausen said that he climbed to the Moon along a bean stalk.

Target my essay is an acquaintance with science, which in turn is still developing today and newer models of rocket science are being created.

Subject is very common and interesting for students to study at this time.

I believe that the essay will really be of interest to many people, since rocketry is in the arsenal of our country, and it is also a common security against enemy attack.

1.K.E.Tsiolkovsky - founder of the theory of space flight

For the first time, the dream and aspirations of many people were 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 first presented scientific proof the possibility of using the rocket for flights into outer space, beyond the Earth's atmosphere and to other planets solar system. Tsiolkovsky called a rocket a device with a jet engine that uses the fuel and oxidizer on it.

2. Jet engine

A jet engine is an engine that can convert the chemical energy of fuel into kinetic energy gas jet, and at the same time acquire speed in the opposite direction.

On what principles and physical laws is the operation of a jet engine based?

As you know from a physics course, a shot from a gun is accompanied by 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 ejected mass of gases creates a reactive force, thanks to which movement can be ensured, both in air and in airless space, and thus recoil occurs. The greater the recoil force our shoulder feels, the greater the mass and speed of the escaping gases, and, therefore, 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 impulses of the bodies that make up a closed system remains constant for any movements and interactions of the bodies of the system.

The maximum speed that a rocket can develop is calculated using the Tsiolkovsky formula:

v max – maximum rocket speed,

v 0 – initial speed,

v r – speed of gas flow from the nozzle,

m – initial mass of fuel,

M is the mass of the empty rocket.

The presented Tsiolkovsky formula 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 mass of the rocket at the end of engine operation - to the weight of the empty rocket.

Thus, we found that the maximum achievable speed of the rocket depends primarily on the speed of gas flow from the nozzle. And the flow rate of the nozzle gases, in turn, depends on the type of fuel and the temperature of the gas jet. 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 greatest number warmth. The formula shows that, among other things, the speed of the rocket depends on the initial and final mass of the rocket, on what part of its weight is fuel, and what part is on useless (from the point of view of flight speed) structures: body, mechanisms, etc. d.

The main conclusion from this Tsiolkovsky formula for determining speed space rocket is that in airless space a rocket will develop a higher speed, the higher the speed of gas outflow and the higher the Tsiolkovsky number.

Let's imagine in general terms a modern ultra-long-range missile.

Such a rocket must be multi-level. The combat charge is located in its head, and control devices, tanks and an engine are located behind it. The launch weight of the rocket exceeds the weight of the payload by 100-200 times, depending on the fuel! Thus, a real rocket should weigh several hundred tons, and its length should at least reach the height of a ten-story building. A number of requirements are imposed on the design of the rocket. So, it is necessary, for example, that the thrust force pass through the center of gravity of the rocket. The rocket may deviate from the intended course or even begin to rotate if the specified conditions are not met.

You can restore the correct course using the rudders. In rarefied air, gas rudders operate, deflecting the direction of the gas jet, proposed by Tsiolkovsky. Aerodynamic rudders work when a rocket flies in dense air.

3. Design of a ballistic missile

3.1. Ballistic missile engine

Modern ballistic missiles primarily operate on engines using liquid fuel. Kerosene, alcohol, hydrazine, and aniline are usually used as fuel, and nitric and perchloric acids, liquid oxygen and hydrogen peroxide are used as oxidizing agents. The most active oxidizing agents are fluorine and liquid ozone, but they are rarely used due to their extreme explosiveness.

The engine is the most important element of the rocket. The most important element of the engine is the combustion chamber and nozzle. In combustion chambers, due to the fact that the fuel combustion temperature reaches 2500-3500 ° C, especially heat-resistant materials and complex methods cooling. Conventional materials cannot withstand such temperatures.

3. Design of a ballistic missile

3.2. Pumps

The remaining units are also very complex. For example, the pumps that must supply oxidizer and fuel to the nozzles of the combustion chamber, already in the V-2 rocket, one of the first, were capable of pumping 125 kg of fuel per second.

In some cases, instead of conventional cylinders, cylinders with compressed air or some other gas are used that can displace fuel from the tanks and drive it into the combustion chamber.

3. Design of a ballistic missile

3.3. Alternative to gas steering wheels

Gas rudders have to be made from graphite or ceramic, so they are very fragile and brittle, so modern designers are beginning to abandon the use of gas rudders, replacing them with several additional nozzles or turning the most important nozzle. Indeed, at the beginning of the flight, at high air density, the speed of the rocket is low, so the rudders control poorly, and where the rocket acquires high speed, the air density is low.

On an American rocket built according to the Avangard project, the engine is suspended on hinges and can be deflected by 5-7 ABOUT. The power of each subsequent stage and its operating time are less, because each stage of the rocket operates under completely different conditions, which determine its design, and therefore the design of the rocket itself can be simpler.

4. Launch pad

A ballistic missile is launched from a special launch device. Usually this is an openwork metal mast or even a tower, around which the rocket is assembled piece by piece by cranes. Sections of such a tower are located opposite the inspection hatches necessary for checking and debugging equipment. The turret moves away as the rocket is being refueled.

5. Flight path

The rocket starts vertically and then slowly begins to tilt and soon describes an almost strictly elliptical trajectory. Most of The flight path of such missiles lies at an altitude of more than 1000 km above the Earth, where there is practically no air resistance. Approaching the target, the atmosphere begins to sharply slow down the movement of the rocket, while its shell becomes very hot, and if measures are not taken, the rocket may collapse and its charge may explode prematurely.

6. Conclusion

The presented description of an intercontinental ballistic missile is outdated and corresponds to the level of development of science and technology of the 60s, but due to limited access to modern scientific materials, it is not possible to give an accurate description of the operation of a modern ultra-long-range intercontinental ballistic missile. Despite this, the work highlighted the general properties inherent in all rockets. The work may also be interesting in order to become familiar with the history of the development and use of the described rockets; it also helped me learn more about rocket science myself.

7. List of references

Deryabin V. M. Conservation laws in physics. – M.: Education, 1982.

Gelfer Ya. M. Conservation laws. – M.: Nauka, 1967.

Body K. World without forms. – M.: Mir, 1976.

Children's encyclopedia. – M.: Publishing House of the USSR Academy of Sciences, 1959.

http://ru.wikipedia.org/wiki/%D0%E0%EA%E5%F2%E0

http://yandex.ru/yandsearch?text=%D1%80%D0%B5%D0%B0%D0%BA%D1%82%D0%B8%D0%B2%D0%BD%D0%BE%D0 %B5%20%D0%B4%D0%B2%D0%B8%D0%B6%D0%B5%D0%BD%D0%B8%D0%B5%20%D1%80%D0%B0%D0%BA %D0%B5%D1%82%D1%8B&clid=2071982&lr=240

8. Evaluation sheet

1. The easiest information was given about the use of missiles; to find out how and what they consist of, one had to look in book materials. The work was easy and interesting.

2. I also support science such as physics. It explains a lot of phenomena, and also this is our future... The essay turned out great and everything is in an understandable form, so that further students will really like the material.

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 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 big sizes, then 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 racer.

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 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.

Jet motion can also be found in the plant world. For example, the ripened 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 by the French writer Cyrano de Bergerac about a flight to the moon appeared. 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. Later he developed a scheme rocket engine on liquid fuel, 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.

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

The idea of ​​K.E. Tsiolkovsky was implemented by Soviet scientists under the leadership of Academician Sergei Pavlovich Korolev. First ever artificial satellite Earth by rocket was launched into 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 a body could interact and thereby change the direction and magnitude of its speed, therefore only jet aircraft, i.e., rockets, can be used for space flights.

Rocket device

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

Any rocket, regardless of its design, always has a shell and fuel with an oxidizer. The rocket shell includes the payload (in in this case this is a spaceship), the instrument compartment and the engine (combustion chamber, pumps, etc.).

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

Fuel and oxidizer are supplied to the combustion chamber using pumps. Fuel, when burned, turns into a 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 out through the bell in a powerful jet special form, called a nozzle. The purpose of the nozzle is to increase the speed of the jet.

Before the rocket launches, its momentum 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 some impulse. Then the rocket is a closed system, and its total momentum must be zero after launch. Therefore, the entire shell of the rocket that is in it receives an impulse equal in magnitude to the impulse of the gas, but opposite in direction.

The most massive part of the rocket, intended for launch and acceleration of the entire rocket, is called the first stage. When the first massive stage of a multi-stage rocket exhausts all its fuel reserves during acceleration, it separates. Further acceleration is continued by the second, less massive stage, and it adds some more speed to the speed previously achieved with the help of the first stage, and then separates. The third stage continues to increase speed to the required value and delivers the payload into orbit.

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

Soviet rockets were the first to reach the Moon, circled the Moon and photographed its side invisible from Earth, and were the first to reach the planet Venus and deliver scientific instruments to its surface. In 1986, two Soviet spaceship Vega 1 and Vega 2 closely examined Halley's Comet, which approaches the Sun once every 76 years.

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

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

Perevoz city
2011
Content:

Introduction: What is Jet Propulsion………………………………………………………… …..…………………………………..3
Law of conservation of momentum……………………………………………………………….4
Application of jet propulsion in nature…………………………..….…....5
Application of jet propulsion in technology…….…………………...…..….….6
Jet propulsion “Intercontinental missile”…………..………...…7
Physical basis of jet engine operation..................... .................... 8
Classification of jet engines and features of their use………………………………………………………………………………….………….…….9
Features of the design and creation of an aircraft…..…10
Conclusion……………………………………………………………………………………….11
List of references……………………………………………………… …..12

"Jet propulsion"
Reactive motion is the movement of a body caused by the separation of some part of it from it at a certain speed. Jet motion is described based on the law of conservation of momentum.
Jet propulsion, now used in airplanes, rockets and spacecraft, is characteristic of octopuses, squids, cuttlefish, jellyfish - all of them, without exception, use the reaction (recoil) of an ejected stream of water for swimming.
Examples of jet propulsion can also be found in the plant world.
In southern countries there grows a plant called "mad cucumber". As soon as you lightly touch a ripe fruit, similar to a cucumber, 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. The mad cucumber (otherwise called the “ladies’ pistol”) shoots at 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 of the bodies of this system with each other.
This fundamental law of nature is called the law of conservation of momentum. It is a consequence of Newton's second and third laws. Let us consider two interacting bodies that are part of closed system.
We denote the forces of interaction between these bodies by and According to Newton’s third law If these bodies interact during time t, then the impulses of the interaction forces are equal in magnitude and directed in opposite directions: Let us apply Newton’s second law 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 possible pair interactions of bodies included in a closed system, we can conclude that the internal forces of a closed system cannot change its total momentum, that is, the vector sum of the momentum of all bodies included in this system. A significant reduction in rocket launch mass can be achieved by usingmultistage rockets, when the rocket stages separate as the fuel burns out. The masses of containers that contained fuel, spent engines, control systems, etc. are excluded from the process of subsequent rocket acceleration. It is along the path of creating economical multi-stage rockets that modern rocket science is developing.

"Application of jet propulsion in nature"
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, 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 shape, copies a rocket. 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.

"Application of jet propulsion in technology"
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. Soviet rockets were the first to reach the Moon, circled the Moon and photographed its side invisible from Earth, and were the first to reach the planet Venus and deliver scientific instruments to its surface. In 1986, two Soviet spacecraft, Vega 1 and Vega 2, closely examined Halley's Comet, which approaches the Sun once every 76 years.

Jet propulsion "Intercontinental missile"
Humanity has always dreamed of traveling into space. Writers - science fiction writers, scientists, dreamers - proposed a variety of means to achieve this goal. But for many centuries, not a single scientist or science fiction writer has been able to invent the only means at a person’s disposal with which one can overcome the force of gravity and fly into space. K. E. Tsiolkovsky is the founder of the theory of space flight.
For the first time, the dream and aspirations of many people were brought closer to reality by the Russian scientist Konstantin Eduardovich Tsiolkovsky (1857-1935), who showed that the only device capable of overcoming gravity is a rocket, he for the first time presented scientific evidence of the possibility of using a rocket for flights into outer space , beyond the Earth's atmosphere and to other planets of the solar system. Tsoilkovsky called a rocket a device with a jet engine that uses the fuel and oxidizer on it.
As you know from a physics course, a shot from a gun is accompanied by 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 ejected mass of gases creates a reactive force, thanks to which movement can be ensured, both in air and in airless space, and thus recoil occurs. The greater the recoil force our shoulder feels, the greater the mass and speed of the escaping gases, and, therefore, 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 impulses of the bodies that make up a closed system remains constant for any movements and interactions of the bodies of the system.
The presented Tsiolkovsky formula 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 mass of the rocket at the end of engine operation - to the weight of the empty rocket.
Thus, we found that the maximum achievable speed of the rocket depends primarily on the speed of gas flow from the nozzle. And the flow rate of the nozzle gases, in turn, depends on the type of fuel and the temperature of the gas jet. 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 produces the greatest amount of heat. The formula shows that, among other things, the speed of the rocket depends on the initial and final mass of the rocket, on what part of its weight is fuel, and what part is on useless (from the point of view of flight speed) structures: body, mechanisms, etc. d.
The main conclusion from this Tsiolkovsky formula for determining the speed of a space rocket is that in airless space the rocket will develop the greater the speed, the greater the speed of gas outflow and the greater the Tsiolkovsky number.

"Physical basis of jet engine operation"
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 stream of “working substance” flowing from the engine, usually hot gases. In all engines there are two energy conversion processes. First, the chemical energy of the fuel is converted into thermal energy of combustion products, and then the thermal energy is used to perform mechanical work. Such engines include piston engines of cars, diesel locomotives, steam and gas turbines of power plants, etc. After hot gases containing large thermal energy have been generated in the heat engine, this energy must be converted into mechanical energy. After all, engines serve to perform mechanical work, to “move” something, to put it into action, it doesn’t matter whether it’s a dynamo, please add drawings of a power plant, a diesel locomotive, a car or an airplane. In order for the thermal energy of gases to transform into mechanical energy, their volume must increase. With such expansion, gases perform work, which consumes their internal and thermal energy.
The jet nozzle can have different shapes, and, moreover, different designs depending on the type of engine. The main thing is the speed at which gases flow out of the engine. If this outflow velocity does not exceed the speed with which sound waves propagate in the outflowing gases, then the nozzle is a simple cylindrical or tapered section of pipe. If the outflow speed should exceed the speed of sound, then the nozzle is shaped like an expanding pipe or first narrowing and then expanding (Lavl nozzle). Only in a pipe of this shape, as theory and experience show, can gas be accelerated to supersonic speeds and crossed the “sound barrier.”

“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 direct reaction. Soon, as you can see from the picture (see below), this trunk is divided into two parts, as if split by a lightning strike. Both new trunks are equally decorated with powerful crowns. This division occurred because all “chemical” jet engines are divided into two classes depending on whether they use ambient air for their operation or not.
In a non-compressor engine of another type, direct-flow, there is not even this valve grid and the pressure in the combustion chamber increases as a result of the high-speed pressure, i.e. braking the oncoming air flow entering the engine in flight. It is clear that such an engine is capable of operating only when the aircraft is already flying at a sufficiently high speed; it will not develop thrust when parked. But at a very high speed, 4-5 times the speed of sound, a ramjet engine develops very high thrust and consumes less fuel than any other “chemical” jet engine under these conditions. That's why ramjet engines.
etc.................