The balloon has neither motors nor the rudder we are accustomed to. Of the entire technological arsenal - only burners, sandbags and a special valve in the upper part of the dome for air etching. How to control this aircraft?
From the history of aeronautics
The birth of balloons was the first real embodiment of the age-old dream of mankind to conquer the fifth ocean. In 1306, the French missionary Bassu first described how, while in China, he witnessed the flight of a balloon during the accession to the throne of Emperor Fo Kien.
However, the French town of Annone is considered the birthplace of aeronautics, where on June 5, 1783, the brothers Etienne and Joseph Montgolfier raised into the sky a spherical balloon created by them filled with heated air.
The flight of an aircraft weighing about 155 kg and a diameter of 3.5 meters lasted only 10 minutes. During this time, he covered about a kilometer at a 300-meter height, which was an outstanding event for his time. Later, balloons in honor of the creators began to be called hot air balloons.
The balloon of the Montgolfier brothers consisted of a linen shell covered with paper. To fill it with hot air, a fire was made from finely chopped straw. And 3 months later, an addition was made to the design of the aircraft in the form of a special basket for passengers.
Modern balloons are undoubtedly more perfect, but they are made in almost the same way. For the manufacture of the spherical shell of the ball, a special thin and durable polyester material is used. The air heating system has changed. The function of the fire is performed by an adjustable propane gas burner installed in a basket directly under the dome.
Despite being heavily dependent on the wind, modern hot air balloons are manageable. The flight height is adjusted by an outlet at the top of the canopy with a break cord. A side valve is provided to change course. There are also more complex designs, where another one filled with helium can be placed inside the main dome.
How to fly a balloon with a basket
Balloon control is an activity that requires serious preparation and considerable financial costs. Suffice it to say that a balloon pilot training course today costs about 200,000 rubles. The price of the balloon itself (depending on the model) is commensurate with the price of a car.
Preparation
The flight is preceded by careful preparation. First of all, it is necessary to study the weather conditions - cloudiness, visibility and wind speed. In accordance with the received data, the flight route is planned. Due to unforeseen changes in weather conditions, it is precisely such a route that is chosen where there are enough places on the way for safe landings.
Takeoff
In order for the balloon to take off, the efforts of the entire crew are necessary. The best option for a starting point is a flat area 50 x 50 meters in an open field, where there are no extraneous objects nearby - poles, trees, power lines.
Then the assembly of the ball begins: burners are attached to the basket, which are connected with special hoses to gas cylinders. After a test run of the burner, the crew proceeds to stretch the canopy (necessarily in the direction of the wind). Further, the stretched dome is fastened to the basket with special carabiners.
The next step is to fill the dome with cold air using a fan, after which the burner is started to heat the air. The heated air lifts the dome from the ground, and the crew (with passengers) takes their places. To prevent the ball from flying away, it is first tied to the car.
Flight
Despite the lack of a motor and wings, the balloon is controllable, which requires certain skills. The main controls are the burners and the exhaust valve. To climb, the burner turns on and the air heats up additionally, and to descend, the valve opens slightly. Horizontal flight occurs due to a tailwind. This is where the skill of the pilot comes into play. So, in order to fly faster, he can increase the flight altitude where the wind speed is stronger.
Descent
The landing site is chosen in advance. It must be large and secure. The ideal option is a football field next to the highway. The crew reports the landing site by radio to the ground. Next, the pilot releases air from the dome using a valve. The ball slowly falls to the ground.
Balloons rise up because the gas that fills them is lighter than the surrounding air. Many gases, in particular hydrogen and helium, have a lower density than air. This means that at a given temperature they have less mass per unit volume than air.
When such light gases are pumped into a balloon, it will rise until the total weight of the gas envelope, basket, weight, and cables is less than the weight of the air displaced by the balloon. (Since air is considered in physics like a liquid medium, the same law applies here as for bodies immersed in a liquid.) Hot air, which has a lower density than cold air, also rises. Although hot air is not as light as some gases, it is safer and more easily produced by propane burners mounted under the neck of the balloon's shell, which is usually made of lightweight fabric such as reinforced nylon. Hot-air filled balloons usually stay in flight for several hours, but without additional heating of the air inside the envelope, they will gradually lose altitude.
Molecules at different temperatures
- When the air is cold, the molecules move slowly and are close to each other.
- When the air warms up,molecules begin to move faster and diverge to the sides, filling a larger volume.
- Since the heated aircontinues to expand, it becomes less dense.
- When the air is cooledmolecules lose their speed, volume decreases and density increases.
- The balloon lies on its side. Propane burners heat the air inside the shell, which causes it to inflate and rise up.
- Hot, light air (picture below the text) rises inside the shell and then flows down along its walls. Cold air is squeezed out through the neck, the weight of the shell with air decreases and the balloon rises.
- Pilots maintain or increase flight altitude by periodically turning on the burners. As long as the air inside the shell is hotter than the outside, lifting force overcomes the force of attraction.
- The balloon descends as the air that fills it cools and contracts. Pilots can accelerate their descent by venting hot air through a hole in the top of the balloon.
Interaction of pressure, volume and temperature
Interdependence of three parameters. The pressure, volume and temperature of a gas are interrelated. At room temperature (near figure on the right), the movement of gas molecules inside the vessel creates a certain pressure. If the volume is > less than half (middle figure on the right), the internal pressure doubles. When air is heated (far right), its pressure increases and its volume increases in proportion to the increase in temperature.
There are several theories to explain the reason for the ability of balloons to fly. In a broad sense, this process is due to the ratio of the weight of air and gas. If the balloon is full...
There are several theories to explain the reason for the ability of balloons to fly. In a broad sense, this process is due to the ratio of the weight of air and gas. If the balloon is filled with gas, then it rises and does not fall to the ground. When it is filled with air, for example, when a person inflates a balloon on his own, his ability to fly is reduced. The gas is much lighter than air, which is why balloons filled with helium fly best.
Depending on the filling, balloons can perform different manipulations.:
- if the balloon is filled with carbon dioxide, air or argon, then it will fly worse;
- neon, methane, nitrogen, helium and hydrogen make the ball take off rapidly due to the minimum weight of these gases and the large difference with the mass of air.
Balloon flight from the point of view of physics
From the point of view of physics, any body placed in a gas or liquid is subject to a displacement force equal to the weight of the body. The balloon in this case is a body "placed" in the air. Because the gas filling the balloon makes it lighter than the air, then a buoyant force begins to be exerted. Due to this, the ball quickly rises up and begins to fly.
With the help of physics, one can also explain the reason for the not very good flying properties of balloons filled with air. The weight in this case is almost the same, so the ball can only hover in the air, but without force, it falls to the ground.
The flight of a balloon in the air is comparable to the navigation of ships on water. In both the first and second cases, the lighter body is pushed out by heavy water or air. Moreover, water and air possess almost the same degree of buoyancy.
Why balloons fly
Large balloons designed for aeronautics fly for the same reasons as small toy balloons. The explanation for the ability to fly in this case is also the laws of physics. The size of the ball, the weight of the basket and the passengers are in close relationship with each other. The ball rises by heating the air in it and the resulting gas. Due to this impact, the ball becomes lighter than air and a buoyant force is exerted on it. 
Balloon control
It is impossible to control any balloons. The main driving force is always air or wind. If you let go of a small balloon and hold it by the thread, then, despite efforts, you will not be able to turn it in the right direction. A similar situation occurs with balls for aeronautics. The only thing passengers in the basket can do is lower the balloon to ground level or lift it higher into the air. Height is gained by reducing weight (special weights are dropped), and the ball is reduced by reducing the amount of gas by controlling the temperature of heating the air inside the rubberized material. The temperature is changed by changing the burner level.
Why are balloons and airships filled with hydrogen or helium
As children, everyone played with balloons. No one wondered why balloons are filled with hydrogen or helium. To answer this question, it is necessary to recall some questions from school course physics. 
A bit of physics
If the body is in the air, several forces act on it. The Archimedean force and weight have the greatest influence. Their difference is called lift. If they are equal, then the balloon hangs freely or moves through the air in intricate curves, the shape of which depends on the currents. If the Archimedean force is greater than the weight, there is a lifting force acting on the balloon upwards. 
The weight of the aircraft is made up of the gas itself, the shell in which it is located, and the load being lifted.
If the shell is filled with ordinary air at a temperature environment, the ball will not rise. The air needs to be heated. Therefore, the balloon must be equipped with a burner for constant heating of the air inside the shell.
The Archimedean force depends on the volume of the shell and the difference between the densities of the air and the gas in it.
As the altitude increases, the temperature decreases, the air pressure and its density in the closed shell decrease. Accordingly, the Archimedean force decreases, and the ball begins to descend. To prevent this from happening, a hole is made in the lower part of the shell, under which a burner is placed. By decreasing or increasing the amount of fuel burned, you can control the flight altitude.
IN aircraft closed-shell gases are used, which, at the same temperature, have a density less than the surrounding air.
Among the available gases, hydrogen has the lowest density. In industry, it is produced in large volumes, so its cost is relatively small.
Today, for safety reasons, the spherical shell of the balloon is filled with helium. This rare chemical element was first discovered using spectral analysis on the sun and was given its name Helios, which means solar. Much later, this gas was discovered on earth.
At the same temperature, the density of helium is 10 times less than air. Hydrogen has an even better indicator - 20. Therefore, initially the balls were filled with hydrogen. But, unlike helium, it is a flammable and explosive gas. Using this element is safe, but a balloon filled with helium has much less lift.
A bit of history
Large balloons are called aerostats, and in the past they were mainly used for scientific research. Most of them were spheres of various diameters.
The largest balloon with a sphere volume of more than 4000 m³ took off in the autumn of 2010. 36 people traveled in its gondola.
The maximum height to which the balloon has risen is more than 21 km. The record flight was made by Indian citizen Vijaypat Singhania in 2005. The balloon was filled with warm air.
At the beginning and middle of the last century, cigar-shaped airships were used to transport people and goods.
The largest airship in the history of mankind, the Hindenburg, was designed in Nazi Germany in the late 30s. He made 21 flights across the Atlantic and died in 1937. At that time there was no helium in Germany and all the Hindenburg tanks were filled with hydrogen. The cause of the accident is unknown. After the tragedy, hydrogen-filled balloons and airships are not used to transport passengers. They are used for scientific purposes only.
Zarechina Kristina
Purpose of the study: find out why a balloon flies away if it is not tied and on what factors the range of its flight depends.
Subject of study: air balloons different size and rubber thickness.
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Balloon riddle
I love my birthday very much. Every year we decorate our house for the holiday with the whole family. And, of course, balloons are an important element of decoration. After all, they are so beautiful! Multi-colored, with beautiful drawings and inscriptions. Usually with my brother we compete in who will inflate the balloon faster with our mouths. We are in a hurry, everyone wants to win, and suddenly, an almost inflated balloon, breaks out of our hands and quickly flies away, rushing around the room until it is completely blown away. I've always wondered why he flies away? After all, it has no engine, no wings ... And what does the range of its flight depend on?
Purpose of the study:find out why a balloon flies away if it is not tied and on what factors the range of its flight depends.
Subject of study:balloons of different sizes and thicknesses of rubber.
Research objectives:
- Conduct experiments showing the movement of the ball.
- Find out how the size of the ball and the thickness of the rubber affect the flight range.
- Find out if there are representatives in the plant and animal world who move like a balloon.
Research hypotheses:
- Suppose the balloon is helped by the wind.
- Assume that the gas in the balloon is lighter than air.
- Perhaps the balloon is helped by the air coming out of it.
Research methods:
- The study of literature.
- Search on the Internet.
- Conducting experiments.
- observation.
- The opinion of other people.
- Comparison and comparison of facts.
A bit of history...
Looking at modern balloons, many people think that this bright, pleasant toy has only recently become available. Some, more knowledgeable, believe that balloons appeared somewhere in the middle of the last century.
And in fact - no! The history of balloons filled with air began much earlier. In former times, painted balls made from animal intestines decorated the squares where sacrifices and festivities were held by noble people of the Roman Empire. After the balloons began to be used by wandering artists, creating decorations with balloons to attract new spectators. The topic of balloons is also touched upon in Russian chronicles - buffoons, speaking for Prince Vladimir, used balloons made from bull bladders.
First balls modern type created the famous English researcher of electricity, professor at Queen's UniversityMichael Faraday. But he did not create them in order to distribute them to children or trade at a fair. He just experimented with hydrogen.
The way in which Faraday created his balloons is interesting. He cut out two pieces of rubber, laid them on top of each other, glued the contour, and poured flour in the middle so that the sides did not stick to each other.
Faraday's idea was taken up by rubber toy pioneer Thomas Hancock. He created his balloons in the form of a do-it-yourself kit consisting of a bottle of liquid rubber and a syringe. In 1847, vulcanized balls were introduced in London by J. G. Ingram. Even then, he used them as toys to sell to children. In fact, it is they who can be called the prototype of modern balls.
About 80 years after that, the scientific hydrogen bag turned into a popular pastime: rubber balloons were widely used in Europe during city holidays. Due to the gas that filled them, they could rise up - and this was very popular with the public, which had not yet been spoiled by either air flights or other miracles of technology.
In 1931, Neil Tylotson produced the first modern latex balloon. And since then, balloons have finally been able to change! Before that, they could only be round - and with the advent of latex, for the first time, it became possible to create long, narrow balls.
This innovation immediately found application: designers decorating the holidays began to create compositions from balloons in the form of dogs, giraffes, airplanes, hats. Clowns began to use them, inventing unusual figures.
Research.
To begin with, I decided to get the opinion of my classmates and students of other first grades. What do they think makes an untied balloon fly away? For this purpose, I conducted a survey. I gave them three answers:
1) The wind helps the balloon to fly.
2) The gas in the balloon is lighter than air, so the balloon flies.
3) The air coming out of it helps the balloon to fly.
- Find out what makes the balloon move.
Hypothesis 1. Suppose the wind helps him.
Let's inflate two balls. We will tie one of them with a thread. Let's go outside on a windy day. Let's release the balls. They fly. A tied balloon flies from gusts of wind. And the one that is not tied flies faster. And then they both fall to the ground. In an apartment where there is no wind, the knotted balloon slowly falls to the floor. And untied - flies, although slower than on the street. And then it falls.
Still, the wind helps the balloon fly. But he flies without wind. So my hypothesis was partially confirmed.
Hypothesis 2. Suppose that the gas in the balloon is lighter than air, so it flies.
I know that the warmer the air, the lighter it is, so the balloon rises. Maybe. Is carbon dioxide lighter than air?
Let's do the following experiment. Take two identical balls. We will inflate one ourselves with carbon dioxide, and the other with the help of a pump with air. We tie them with a thread and throw them over a stick. We see that the balloon, inflated with carbon dioxide, sank lower. So it's heavier. In the reference book, I found confirmation of my conclusion. It turned out that carbon dioxide is 1.5 times heavier than air.
This hypothesis turned out to be false.
Hypothesis 3. Perhaps the balloon pushes the air coming out of it.
When we inflate the balloon, the rubber shell expands and fills with air. When we release the inlet, the air bursts out with force. The ball is then reduced. The air from the balloon flies in one direction, and the shell of the balloon in the other. They repel each other. The path of the ball is unpredictable. When all the air is out of the balloon, it stops.
I asked the physics teacher Sergei Vyacheslavovich about this. He said that the ball flies away under the action of a reactive force. Jet motion occurs when a part of it is separated from the body at a certain speed.
This means that the balloon pushes the air that comes out of it. My balloon is reactive.
- Conduct experiments showing jet propulsion.
Let's do a few more experiments showing the reactive motion of the ball.
- Inflate a balloon, insert a bent tube and tie. We attach the ball to a small typewriter. The tube should look back. Release the tube. Air comes out backwards. The car moves forward under the action of reactive force.
- We lower the same ball with a tube into a bowl of water. The tube should look to the side. Release the tube. The ball begins to rotate on the water under the action of the reactive force.
- Find out how the shape of the ball and the thickness of the rubber affect the flight range.
I wonder what factors determine the range of the ball?
Let's take balls of different size and thickness of rubber and conduct an experiment.
Take the fishing line and pull it around the room. We will put a part of the straw on the fishing line. We will inflate the balloons with a pump with the same amount of air (10 strokes). We attach the balls to the straw with tape and release. The ball will fly some distance along the line and stop. Let's measure the distance travelled.
For clarity, we will fill in the table of results.
Conclusion : The thicker the rubber and larger size ball, the farther it flies.
- Are there representatives in the plant and animal world who move like a balloon.
Reactive motion can be observed in wildlife.
Jet propulsionused by many shellfish.
Octopuses, squids and cuttlefish have a special pouch. They collect water into it and release it with a strong stream outward. This jet pushes the animal back. Squid can reach speeds of up to 60–70 km / h.
The sea scallop mollusk, sharply compresses the shell valves, jerkily moves forward due to the jet stream of water ejected from the shell.The jump of a large scallop can reach half a meter or even more in length.
Salpa - a marine animal with a transparent body, when moving, it takes water through the front hole and pushes it out through the back hole. So she moves forward.
Medusa pushes water out from under her bell-shaped body, receiving a push in the opposite direction.
Examples of jet propulsion can also be found in the plant world.The ripened fruits of the “mad” cucumber, with a light touch, bounce off the stalk, and liquid with seeds is ejected with force from the hole formed; the cucumbers themselves fly off in the opposite direction. Shoots "mad" cucumber more than 12 meters.
- Find out how scientists used knowledge about such a movement.
One of the most important inventions of mankind in the 20th century is the invention jet engine that allowed man to ascend into space. This is how rockets appeared, and then jet aircraft. Later andThe engineers created an engine similar to a squid engine. They called him a water jet. Such an engine is found on some speedboats.
Fun and helpful!
studying this topic, I found information that blowing up balloons is not only fun, but also useful! It turns out that they "give" health to our lungs. Inflating balloons has a positive effect on our throat (even serves as a means of preventing sore throats), and also helps to strengthen our voice. Singers often use this aid, as such training helps them breathe properly while singing.
Conclusion
So, let's summarize ... In the course of studying this topic, I found out that, firstly, the wind still helps the balloon fly, but when it is not tied, it also flies in a buried room without wind. My second hypothesis was not confirmed, the carbon dioxide that we exhale is not lighter, but heavier than air, therefore it cannot help the balloon fly away. My third hypothesis was fully confirmed, that the air coming out of it helps the balloon to fly. I found out that in this case, the balloon moves under the action of a reactive force. I also conducted experiments and found that the flight range of a balloon is affected by its size and the thickness of the rubber from which it is made.
Thanks to the study of this topic, I learned a lot of new and interesting things. I got acquainted with the history of the creation of the modern balloon and its predecessors. I learned that the gas we exhale is called carbon dioxide and that it is one and a half times heavier than the air we breathe. I learned to do various interesting experiments myself, to observe, compare the results and draw conclusions. I was introduced to jet propulsion, although I won't be studying physics anytime soon. I learned that in nature there are animals and plants that use jet propulsion. It also turned out that inflating balloons is not only fun, but also good for health.
I believe that this work can be used in the classroom to demonstrate the action of reactive force in a simple and colorful way, to clearly show that carbon dioxide is heavier than air. After all, when we ourselves spend various experiences or watching them being carried out, it is easier for us to understand the principle of something, especially if these experiments are so bright and fun!
The Archimedes force, or buoyant force, acts not only in liquids (for example, water), but also in gases (for example, air). But due to the fact that the density of air (1.29 kg / m 3) is much less than that of water (1000 kg / m 3), the buoyancy force is negligible here.
That is why many objects do not float in the air as they do in water. The force of gravity acting on the body is stronger than the buoyant force of air.
However, as in water, the more volume a body occupies with a constant mass, that is, the more its average density decreases, the more buoyant force will act on it.
In addition, there are gases whose density is less than that of air. These are hydrogen and helium. Also, the air itself expands when heated, and its density decreases.
If you fill a balloon with a lighter-than-air gas, the buoyant force of the air will lift it up. But since the buoyant force of the air is not great, the material of the ball has a noticeable mass, and baskets with people and other loads are attached to the balls, the balls themselves must be huge. They must contain enough lighter gas to fill a large volume so that the buoyant force acting on this volume exceeds the weight of the entire balloon.
Currently, flying balloons are usually filled with helium, since it does not burn like hydrogen, therefore it is safe. Previously, balloons were filled with heated air. Under the ball was a burner. The level of fire in it could regulate the height to which the ball would rise.
Air with height becomes more rarefied, i.e. less dense. Therefore, balloons cannot rise high.
