The biographies of great people are often drawn according to the same scheme: in childhood, the future great person already begins to have extraordinary abilities that delight relatives and friends, then a triumphal march to fame follows, and in conclusion - a calm old age in the circle of loving grandchildren and followers. In fact, biographies are as varied as the people themselves. An example is the life of the great Russian scientist and engineer Nikolai Yegorovich Zhukovsky.
THE FIRST STEPS OF A SCIENTIST
To begin with, this wonderful mathematician at the beginning of his school life was the worst mathematician in the class. However, he worked hard and graduated from high school with a medal.
They say that talent is above all the ability to work. Zhukovsky's life gives every reason for such a statement.
From early childhood (Zhukovsky was born on January 17, 1847), he was accustomed to persistent mental pursuits. At the same time, the boy was fond of reading science fiction novels. Jules-Vernov's "Airship" has long been preserved in the Zhukovsky library among serious scientific books.
After graduating from the gymnasium in Moscow, the parents recommended the young man to enter Moscow University. He didn't want that. He wrote to his mother: "When I graduate from university, there is no other goal than to become a great person, and this is so difficult: there are so many candidates for the great."
Following the example of his father, he is going to become a railway engineer. But in order to go to study in St. Petersburg, where the Institute of Railway Engineers was located, money is needed, and this is what Zhukovsky lacked most of all.
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And now 17-year-old Zhukovsky is a student of the Physics and Mathematics Faculty of Moscow University. He was denied a scholarship. Financially constrained, he ran through the lessons, prepared and published lectures, lived more than modestly. At times it was very difficult. Then he would lay his fur coat, which served as a blanket at the same time, and ran in winter in a light coat, which "not only does not warm," he complained, "but is terribly cold."
But for all that ZhZhukovsky did a lot. Not content with completing a compulsory university course, young Zhukovsky was engaged in a scientific mathematical circle. Wonderful university professors - Zinger, Stoletov - awakened the tremendous thirst for knowledge hidden in the young man, thirst for creative work. In 1868 - 21 years old - Zhukovsky received the degree of candidate of mathematical sciences.
Wanting to receive a practical education, he nevertheless entered the St. Petersburg Institute of Railway Engineers. But the future great engineer … failed the exam.
After leaving the institute, he began teaching, first at a female gymnasium, then at the Moscow Higher Technical School. From that time, for half a century - until the end of his life - he tirelessly trained in the walls of the school cadres of Russian engineers. One of the brightest sides of Zhukovsky's multifaceted talent came to light in pedagogical work.
However, Zhukovsky did not stop scientific activity for a single day. He began to study the kinematics of a liquid body, that is, the laws of motion of liquids.
By that time, the theory of the motion of a rigid body was already well developed. Everything was clear here. In the mechanics of liquids, there were only the first timid investigations. The formulas obtained did not recreate a clear picture of fluid movement and could not always be applied.
In his first major work, Zhukovsky examined in detail the most complex motion of a particle in a fluid flow. After performing a serious mathematical analysis and analyzing all the previous works of other scientists, he showed surprisingly simply, clearly to everyone, what is done with a particle in a fluid flow: it moves forward, rotates around an axis and changes its shape from a ball to an ellipsoid.
The solution to this problem brought the young man a master's degree.
A NEW DREAM
The young master went abroad. He attended lectures by leading scientists, met with engineers and inventors.
Here he first met with aeronautical researchers. There were no airplanes at that time. But man's thought turned more and more stubbornly to this idea. In different countries, researchers appeared who built models of apparatus heavier than air and performed all kinds of tests with them.
Professor Langley in Washington built a flying device powered by a steam engine.
These models were usually driven by small motors. Thus, for example, Professor Langley in Washington built an aircraft driven by a 1 horsepower steam engine. During the tests, this device-author called it “airfield” - it flew 160 meters against the wind in 1 minute 46 seconds. This result will seem very modest to modern aircraft modelers, but then, at the dawn of aviation, it was a real achievement.
Abroad, Zhukovsky observed flights of models built by European designers. Much of the mystery of the flight had not yet been solved. Rather, everything was unclear here. Some riddles. And from that time to the grave, Zhukovsky was seized by the dream of conquering the air element.
THE ROAD TO THE CONQUEST OF AIR
He saw that practically in this area people had not yet achieved anything. Zhukovsky took many models with him to Moscow. Let's figure it out at home! He also brought with him an interesting novelty - the bicycle of the French inventor Michaud. This machine was a little like a modern bicycle. She had a huge front wheel with pedals and a small rear one. It took a lot of art to ride such a bike.
In the vicinity of the village of Orekhovo, Vladimir province, where Zhukovsky spent his summer in 1878, one could observe a curious sight. A bearded man with … wide red wings on his back rode across the field on a high bicycle. The wings were made of bamboo and covered with fabric.
Riding a bicycle at various speeds, Zhukovsky tried to comprehend the secret of the lifting force of the wings. He was interested in how it changes in different conditions and on which parts of the wings it acts more strongly. Thus, in a combination of a thinker and an experimenter, the style of work of the great Russian scientist was formed.
Soon Zhukovsky defended his doctoral dissertation "On the strength of motion". By this time, he had already irrevocably chosen his main line in science. He worked on a wide variety of problems of his time. But no matter what he had to do, he was no longer left with the thought of flying.
From year to year, he developed the theory of flight. In November 1889, in the Society of Natural History Lovers, he presented "Some Considerations on Aircraft." In January 1890 Zhukovsky appeared at the rostrum of the congress of Russian doctors and naturalists with a report on the topic "Towards the theory of flying." In October 1891, at a meeting of the Moscow Mathematical Society, he made a report "On the hover of birds."
In this last work Zhukovsky, among other things, proved the possibility of realizing a "loop" in an airplane. This was before the first plane took off. Almost a “dead loop” was first implemented almost a quarter of a century later by the famous Russian pilot Nesterov.
Designers in all countries tried to find a solution to the problem of human flight in blind imitation of birds. Numerous inventors thought that by attaching wings to themselves, a person could rise into the air with the power of his muscles. They forgot that the ratio of muscle weight to body weight in humans is seventy-two times less than that of birds. They did not even consider the fact that a man is eight hundred times heavier than air, while a bird is only two hundred times. And so all attempts to fly "like birds" invariably ended in failure.
Airplane designers blindly imitated birds, thinking that by attaching wings to themselves, a person could rise into the air with the strength of his muscles.
Zhukovsky, on the other hand, saw other ways of developing aviation: "I think," he said, "that a man will fly relying not on the strength of his muscles, but on the strength of his mind."
He had already seen in his imagination airplanes built according to the laws of aerodynamics, flying freely in the air ocean. But such laws still had to be found, and the planes had to be created. And the creator of aerodynamics - the science of the motion of bodies in the air - was Zhukovsky himself.
Aircraft have been worked hard in many countries. Next came the engineer and inventor Otto Lilienthal. The style of his work was in part reminiscent of Zhukovsky himself: theory combined with experiment.
“In flying technique,” said Lilienthal, “there is too much reasoning and too few experiments. Observations and experiments, experiments and observations are needed.
Lilienthal created a glider, that is, an aircraft without an engine.
Lilienthal carefully studied the action of flapping wings, tried to unravel the mystery of storks soaring into the sky, tested various planes, placing them at different angles in the air stream, and observed ascending air currents. All this allowed Lilienthal to create a glider, that is, an aircraft without an engine, which rose above the take-off site during tests.
Zhukovsky, having met Lilienthal, immediately recognized the correctness of the path he had chosen, and the glider built by him was the most outstanding invention in the field of aeronautics of that time.
A creative friendship developed between the two researchers. Zhukovsky helped Lilienthal with advice and theoretical substantiation of some issues. Lilienthal introduced Zhukovsky to the practical results of his experiments and presented him with one of his gliders. This glider subsequently helped Zhukovsky to put together a circle of flight enthusiasts in Moscow.
But Zhukovsky looked beyond Lilienthal. He considered the glider only as a good tool for investigating the issues of flying. The creator of aerodynamics prophetically saw the future of aviation in an airplane. Many years before the first flight of the Wright brothers on the airplane they built, Zhukovsky realized the stages of creating this machine: first, study the glider well, then put a motor on it - and then the person will fly.
In this he had unshakable confidence. In 1898, he boldly proclaimed: "The new century will see a man flying freely through the air." No setbacks scared him, not even the numerous catastrophes at that time, one of which was Lilienthal himself. The death of Lilienthal "for courageous explorers of the air, - said Zhukovsky, - … inspires a sense of awe for the deceased, but not a feeling of fear."
FIRST AERODYNAMIC INSTITUTE
The beginning of a new, XX century was also the beginning of a new era in the life and work of Zhukovsky. In 1902, he built the first wind tunnel at Moscow University.
Abroad, they tried to test aircraft models in special galleries, through which air was driven with the help of fans. But the blower fans created air turbulences that distorted the picture and made the test unlike actual flight conditions.
The Russian scientist acted differently. He made the fans not pump, but pump air out of the gallery. The air flow moved in it evenly at a speed of 30 kilometers per hour. This is how the world's first suction wind tunnel was created. She was modest in size - 75 cm in diameter. This pipe later served as a model for a whole series of such devices built in Russia and abroad. On the basis of this first scientific laboratory of his, Zhukovsky began to put together a group of aerodynamic researchers from university students.
Zhukovsky made the fan not pump, but pump air out of the gallery. This is how the world's first suction wind tunnel was created.
In 1904, he created near Moscow, in Kuchin, the world's first institute specially equipped for aerodynamic research. The famous Göttingen Aerodynamic Institute Prandtl, in Germany, appeared only five years later, having already had Zhukovsky's experience.
In the Kuchin Institute, in addition to the wind tunnel, there was already other equipment: a hydrodynamic laboratory, a physics room, a special device for researching propellers, workshops, etc. Zhukovsky began by studying various forms of wind tunnels. The results of his research helped Prandtl and other foreign researchers in the construction of their laboratories.
The behavior of the planes in the air flow was studied, the propellers were studied. The first dynamometer to measure the propeller thrust was built in Kuchin.
In parallel, a lot of work was done to study the atmosphere. For this, small balloons were used, which were launched upward with meteorological instruments that automatically record temperature and air pressure and other data. Such balls - probes, as they are called, are still used for this purpose.
THE BIRTH OF AVIATION
Particular attention was paid at the Kuchin Institute to the study of the lift of an aircraft wing.
How is lift generated? How can it be calculated? For centuries, mankind has tried in vain to answer these questions, paying for their attempts with the lives of their best sons.
Zhukovsky answered these questions.
Around the wing of the aircraft, when it flies, in addition to the main oncoming air flow, an additional vortex motion of air particles is formed. These additional vortices wash the wing and create circulation around it. If the wing is curved and has a bulge at the top, then the air flow at the top of the wing is compressed, and its speed increases.
Hang up two sheets of paper, bend them as shown in the figure, and blow into the space between them - the sheets will not disperse, but will converge.
Let us recall the well-known physical experience that so amazed many of us at school. We can even repeat it, as it doesn't require anything but two sheets of paper. Take two sheets of paper and, bending them slightly, we will hold them close to each other with convex sides. Now let's blow into the space between them. Contrary to expectations, the sheets will not disperse, but will draw closer to each other.
This is a clear confirmation of the famous Bernoulli's law. It characterizes the relationship between the flow rate and its pressure on the bodies with which it comes into contact. The higher the flow rate, the lower the pressure, and vice versa. In our experience, an increase in the speed of air movement between the sheets decreased the pressure between them, and the sheets therefore moved closer together.
But something similar happens with a wing in an air stream. At the top of the wing, the air speed increases, which means, according to Bernoulli's law, the air pressure decreases. At the bottom of the wing, the opposite picture: due to the concavity of the wing, the air flow here expands and its speed decreases, and therefore the pressure increases.
This creates a pressure difference between the top and bottom of the wing. It is she who creates the lifting force.
This force can be calculated. To do this, as Zhukovsky showed, you need to know four quantities: the flow rate, the amount of circulation, the wing length and the air density. The product of these quantities will give the lifting force.
But for the plane to take off, there must be circulation, that is, air washing the wing. How can this be ensured?
For the formation of circulation, the presence of sharp edges at the streamlined contour is necessary. But there shouldn't be many of them. The smooth flow that is required is possible only if the contour has no more than two sharp edges. If we take just two edges, then a new inconvenience arises: although a smooth flow will occur, but not always, but only at a certain constant angle of inclination of the aircraft wing to the air flow, which is practically difficult to implement in flight.
Thus, it follows from Zhukovsky's reasoning that the most appropriate for the wing should be recognized as a contour with one sharp edge. But this is exactly the shape of the wing section of the 1946 aircraft: Zhukovsky found it over forty years ago.
The results of these studies were formulated by Zhukovsky in a paper published under the modest title "On attached vortices" (since the study dealt with the attachment of those vortices that form around the wing to the main flow velocity).
Now aerodynamics has become a science. From that day to the present, Zhukovsky's theory of lift has been presented in all textbooks on aerodynamics in the world. From now on, the aerodynamic calculation of the aircraft became possible.
It was a really great day for aviation. It should be considered the birthday of aviation. After all, the first practical flight of the Wright brothers or any other flight at that time was, in essence, only a trick - albeit an outstanding one, but still a trick.
Even dozens of such flights could not contribute to the development of aviation as much as one formula of Zhukovsky did. Now there was no need to blindly invent airplanes, they could be calculated in advance, designed according to these formulas.
Zhukovsky wanted to do it. But the owner of the institute, the millionaire Ryabushinsky, “did not find” the money to build an experimental aircraft, and soon announced that, in his opinion, all the main problems of aerodynamics had already been clarified.
Zhukovsky had to leave the institute.
ENCYCLOPEDIA OF AVIATION SCIENCE
In 1909 Zhukovsky created a new scientific institution - the aerodynamic laboratory of the Moscow Higher Technical School. Zhukovsky sought to "lure as many Russian forces into science as possible." The circle of Zhukovsky's students became a breeding ground for outstanding figures of Russian science. It was from this circle that academicians Yuryev, Chudakov, Kulebakin, outstanding scientists and designers: Tupolev, Mikulin, Klimov, Vetchinkin, Stechkin, Sabinin, Musinyants, the famous pilot Rossinsky and many others came out.
With the help of the members of this circle, Zhukovsky created his wonderful works. A special place among them is occupied by the theory and method of calculating propellers. Zhukovsky's students Yuryev and Sabinin, starting, as their teacher always did, with an experiment, came to the conclusion that a working screw creates a powerful axial air flow. This very important phenomenon has not been taken into account before by any researcher. Abroad, the corresponding amendment to the theory was made only ten years later.
Soon Zhukovsky, having studied a number of new phenomena with the help of Vetchinkin, proposed an even more perfect theory of the screw. His work "The Vortex Theory of the Propeller" marked a new era in science. The formulas and theorems of this theory cover all cases of screw operation. The significance of the vortex theory goes far beyond aviation; her theorems served as the basis for the design of powerful fans and compressors. Zhukovsky wrote this work 35 years ago *. But even today, all over the world, when calculating screws, they use Zhukovsky's formulas.
* The article was written in 1946.
Zhukovsky, with the help of Chaplygin, developed an ingenious theory of aircraft wings. The wings built on the basis of this theory are called "Zhukovsky's wings" in all languages of the world.
With the participation of his other student, Tupolev, Zhukovsky developed methods of aerodynamic calculation of the entire aircraft.
Aviation began to develop rapidly in Russia. Aircraft designs began to appear, far ahead of foreign models. This seemed surprising given the general technical backwardness of Russia and the complete indifference of the tsarist government to the new branch of technology.
We now know the secret of this success. It was caused by the brilliant state of the Russian aerodynamic science, which took the most advanced positions in the scientific world. The laws of this science were formulated and systematized by Zhukovsky in his famous first in the world course "Theoretical Foundations of Aeronautics". This course was like an encyclopedia of aviation science.
Before Zhukovsky, it was believed that there is no place for theory in aerodynamics, that this is an area of pure practice. "Foundations" first showed the possibility and necessity of studying aviation in a theoretical way. At the same time, Zhukovsky emphasized the enormous importance of correctly staged experiments.
The "Theoretical Foundations of Aeronautics" established an unshakable connection between theoretical and experimental research as the main prerequisite for the further development of aviation.
GREAT SCIENTIST, ENGINEER, TEACHER
Zhukovsky was not only an aerodynamicist. 180 scientific papers written by him touch on the issues of mathematics, mechanics - theoretical, applied and construction, - astronomy, ballistics and many others. He was a great scientist and a great engineer.
Interesting solutions to difficult engineering problems are contained in Zhukovsky's works "On the shape of ships", "On a wake wave", "On the stability of the flight of an oblong projectile", "Bombing from airplanes", "On the rotation of a spindle."
Zhukovsky was not afraid of practical problems. On the contrary: he loved them. They gave him the basis for creating new theories.
For example, they turned to Zhukovsky somehow for help in such a purely practical matter. There were frequent accidents at the Moscow water supply system: main pipes burst for no apparent reason. Zhukovsky found that one of the main causes of these accidents was the shock effect of water, which developed in the pipes when they were quickly opened or closed. The accidents stopped as soon as special taps were installed on the pipes, slowly blocking the access of water. The so-called valves.
This was a practical conclusion. It was followed by a theoretical one. Zhukovsky created a general theory of hydraulic shock in pipes, which was later published in all languages and included in all textbooks on hydraulics.
Zhukovsky was very popular and touching love of the students. He was not only a lecturer, but also an educator. He was especially concerned about the development of engineering thinking, about the technical outlook of young men. He passionately wished to pass on all his knowledge to young people in order to further advance Russian science.
Almost on the eve of his death, without getting out of bed, Zhukovsky said: “I would also like to read a special course on gyroscopes. Nobody knows them as well as I do. He was a great teacher.
Zhukovsky's scientific achievements were widely recognized. Nikolai Yegorovich was a corresponding member of the Russian Academy of Sciences, an honorary member of many scientific Russian and foreign societies.
But Zhukovsky, a man of the greatest modesty and selflessness, did not seek fame. He refused to be elected a full member of the Academy of Sciences, since he could not combine work in Moscow and St. Petersburg, where the Academy was then located, and did not consider it possible to agree to a formal election to a member of the Academy of Sciences.
FOUNDER OF AVIATION SCIENCE
Zhukovsky met the Great October Revolution as a seventy-year-old man.
Zhukovsky forgot about his old age. He came to the Supreme Council of the National Economy with a project to create an institute of aerodynamics and hydrodynamics. In 1918, in a year of poverty and devastation, Lenin signed a decree on the organization of TsAGI - the Central Aerohydrodynamic Institute. named after N. E. Zhukovsky.
The institute began its existence in one of the rooms of its founder's apartment. But in Zhukovsky's imagination, the walls of his apartment were moving apart, he saw his institute as mighty, wealthy, ahead of world aviation science, as we know TsAGI now.
Zhukovsky created the Air Force Academy named after him. On his initiative, training of aeromechanics was introduced at the Moscow Higher Technical School. Today the Moscow Aviation Institute has grown on this base.
And when in 1920 the fiftieth anniversary of Nikolai Yegorovich Zhukovsky's scientific activity was celebrated, in the resolution of the Council of People's Commissars, signed by Vladimir Ilyich Lenin, the great scientist was deservedly called “the father of Russian aviation”. This was the real creator of Russian aviation, her father. And at the same time, he was the founder of all aviation science in general.
Nikolai Yegorovich Zhukovsky died on March 17, 1921. He was seriously ill, but continued to work almost until the day of his death. When he was no longer able to write, he dictated his notes to his students. He did not want to give death a single day, not a single hour. The great worker and great patriot gave all his strength to his last breath to his people.
D. Berkovich