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The airplane

The airplane
The idea of ​​aircraft - one of the oldest in the history of mankind. In the myths, legends, historical records can be found on a variety of evidence taken in different centuries of human attempts to realize his dream to take off and fly like a bird. But these were amateurish enterprise, which can be seen more enthusiasm than calculation, and because they invariably ended in failure. there were first indications that a flight on machines heavier than air and may someday become a reality only in the last quarter of the XIX century. Why is art so long remained an unattainable dream for a man? The fact that, unlike an airplane not balloon floats in the air, and it is based on a flight, submitting complex aerodynamic laws.

The correct explanation of the phenomenon of the flight has been given in the XVIII-XIX centuries, but the science of the art of fly - Aerodynamics - appeared only in the first decades of the XX century. Why birds, although they are heavier than air and does not fall to the ground? The fact that the air in the lower surface of the wing has a so-called lifting action of force which exceeds the force of gravity acting in the opposite direction. Where does this force, explained in the first half of the XVIII century, the famous mathematician and physicist, Bernoulli. In 1738 in his major work "Hydrodynamics" he deduced the law, now bears his name. The essence of the law of Bernoulli (he formulated for liquids, but also just for gas) is that with the increase of the flow rate on the pressure vessel wall decreases. Action Bernoulli law is very easy to observe the experience Take, for example, a piece of paper and we will blow it - the far edge of the sheet immediately rise up, as if something is pushing it from the bottom. This "something" is already mentioned lift. It arose due to the fact that the air above the surface of the leaf is moving a lot faster than what is underneath. Consequently, the pressure on the top sheet is considerably less than atmospheric pressure that presses it from below. If the lift is greater than the force of gravity, the leaf rises.

However, the situation of our experience is not easy to replicate in a real situation. To lift the edge of the leaf, we deliberately blew it as it was convenient for us. And how to make ascend winged any device which is in the real air flow? Obviously, this wing unit should be flat as a sheet, and have such a shape that its flow velocity above and below have varied - slower bottom than at the top. Then the pressure on the top surface of the wing is smaller than the bottom. Lifting force can be adjusted by changing the angle of attack (the angle between the so-called wing plane and the air flow). The greater the angle of attack - the greater the lift.

But take off a little - you should be able to keep the airplane in the air. After all, lift only lasts as long as the bearing surface of the wing is correctly oriented with respect to the air flow. Disturbed orientation - lost lift, and an airplane crashing to the ground, like a fall through the hole. Stability - this major problem for any flying machine heavier than air. If he does not have a mechanism to ensure the stability, it turns into a toy treacherous wind. The dangers lie in wait for such a machine at every step. Any gust of wind or a wrong maneuver of the pilot could lead to the fact that the airplane rolls onto its side or nose, turn over and fall.

Fortunately, the first aviators had though vague, but the true idea of ​​the dangers awaiting them and managed to some extent, to prepare for him. The first step in the sky was made with the help of models. Direct precursor of all modern aircraft should perhaps be considered toy airplanes Peno, which he built in 1871 and ran a motor with rubber. Weighing a few grams they flew a few dozen seconds. These models can be said to have been the first visible evidence that the machines heavier than air and can fly at all. In 1872 Peno came to an extremely important conclusion that for stable flight of the airplane he needs empennage. Soon he was able to give their devices a good stability with respect to all three axes.

However, this was only the beginning. Thirty years before being able to create a plane, able to lift a person in the sky. At the end of the XIX century in different countries it has made several attempts the construction of large airplanes with powerful engines. In 1894, a huge plane with a wingspan) 31, 5 m and a weight of about 3, 5 tons tried to lift into the air the famous inventor Hiram Maxim. But at the first attempt the car was smashed. Maxim has spent on its experience of 20 thousand pounds, did not return to the construction of the aircraft. The famous American astronomer Samuel Langley, received from the US government $ 50 thousand in the early 1900s built a few large aircraft, which invariably broke during each attempt to get off the ground. In France, similar experiments and with the same success was engaged at the end of the 90s the engineer Clément Ader. Having spent his machines around 500 thousand francs, the French government has denied to the inventor in the future grants.

In general, the path chosen by Maxim, Langley, Hadad, and some other inventors, proved a dead end. The development of aviation took a different road, which have German inventor Otto Lilienthal. While others have paid their attention to the "motor flight" Lilienthal set a different goal - to grasp first of all non-motorized secret soaring. Instead of expensive cars he built lightweight gliders and worked hard to improve them. It seems that the idea of ​​a glider is the first of what should have thought aviators, but in reality everything was different. Until the XIX century inventors at their attempts to get off the ground to imitate the flight of birds rowing. Because of this persistent effort to follow the nature of man has mastered relatively late gliding flight. Meanwhile, the technical possibilities for such a flight had already been in ancient times. A common misconception was the fact that the flight, except for the wings, also suggested the presence of some sort of mechanical force. It is at this point, and focused efforts of inventors.

For the first time attention to the soaring attracted snapshot. The famous German photographer Ottomar Anshyutts, which has already been discussed in a previous chapter, made a series of pictures of a stork flying. They say that these pictures were in 1890 on the eyes of Otto Lilienthal and led him to the idea to build a glider. Indeed, photos Anshyutts conclusively showed that the air can such a flight, in which the work necessary for the movement and the rise of the aircraft is carried out not by himself, and air. Some photos depicted soaring storks, which lifted up a gust of wind.

The first glider Lilienthal consisted of a willow covered with cloth frame, forming a rounded, concave like a bird's wings on two levels with a small tail behind. The entire unit weighed only 20 kg. Lilienthal was suspended to him, threading his hands in two wings attached under the belt, and ran down the hill into the wind. At first he kept the wings angled front edge downwards, and then substituted lower wind their surface and raising wings, glided over the rising flow. The balance is maintained by balancing the body forward, backward and sideways. Initially, the flights were very short - 15 meters and made a small sandy hill. Then they became longer and occurred from the hill 30 meters high. From 1891 to 1896 Lilienthal made over 2000 successful gliding flights. In the end he could fly more than 100 meters, while in the air up to 30 seconds. Thus, the first to prove the possibility of Lilienthal gliding flight and the first well came to the study of aerodynamic forces acting on the wing. Lilienthal experiments attracted the attention of many countries. Soon he appeared followers. But in August 1896, during one of his missions, a sharp gust of wind picked up, Lilienthal fell from a height of 15 meters and broke his spine. On the same day he died.

In the future, a great influence on the development of aircraft was the experience of the American Octave Chanute. His first gliders were built on the model of Lilienthal's glider. Chanute was then make various changes therein and eventually created with smooth biplane wing. He also paid great attention to design of the tail, putting it moving elevators and direction. This glider became a landmark structure in the history of aviation. Simple, efficient, lightweight, but at the same time strong, he was the best aircraft of its time. The most striking feature - wing design with horizontal contours - has become common in the future. Chanute was the first who has ceased to slavishly imitate the form of the bird's wing. However, the alignment of the airframe was the same as in Lilienthal - pilot hung from the bottom on the belts and balancing your body, supported device stability. However, Chanute remained a rare visitor in the sky. The duration of his flight is measured in seconds, and the range - tens of meters.

Flight Art in the true sense of the word for the first time in history mastered the brothers Wilbur and Orville Wright, owners of a bicycle shop in a small American town of Dayton. They began their experiments at a time when aviation was established dull lull: flying machines Ader and Maxim, which cost a lot of money, do not fly, brave Lilienthal glider crashed. The immediate goal, which set themselves Wright, was to achieve sustained and controlled flight. In 1899 they made their first (and as it turned out later, the most remarkable thing) discovery - they have established that to ensure lateral stability of the airplane is necessary to distort the ends of its wings. This idea came to Wilbur Wright. One day, bending the carton, he suddenly thought that in the same way you can bend the ends of the wings of an airplane - one up, the other down - and thus save him from zavalivanija in the side. After that, Wright began to think of his first glider device and choose the scheme that was created Chanute - biplane with two supporting surfaces, located one above the other.

His first glider brothers built in 1900. He faithfully reproduced units Chanute and only in size greatly surpassed them. But there were some differences. Wright rejected the tail, which, they said, "is more a source of trouble than help." They refused and the stability of the regulation by moving the center of gravity of the machine and provided a real rudders. Ahead of the airframe they put a horizontal surface - so-called "elevator". Evade this surface up and down, it was possible to align all the vibrations from the direction of flight (longitudinal stability). Lateral stability is ensured by torsion of the wings. It was the first ever glider confidently helm. It perfectly withstood the test - not only easily soared into the air, but also raised human. The pilot is not suspended here on the belts below the unit, as has happened before in other designers, as well as the lay on the sled. In 1901, Wright built a second glider for the first sample, but only larger.

Will test these devices, they were convinced that they were severely lacking theoretical knowledge of aerodynamics. However, while this science was in its infancy. Having collected all the books devoted to the description of the flight bodies, which they were only able to get it, Wright made sure that not will be able to fly on such baggage. they are missing the table decided to make their own. Measuring the resistance forces of moving bodies in the air can be produced in two ways: either moving the body at a certain speed for still air or blow motionless body, directing him with a certain air speed. Langley and Maxim made his experiments only the first method, rotating objects or models of a hand through the air. In this process, it was very difficult to measure the angle at which was to rotate the plane or a model in one point or another. In addition, test results distorted by the influence of centrifugal force. It is not surprising that they were contradictory and inaccurate. Wright chose the second method. In the same year they built a "wind tunnel" - a wind tunnel in which air is blown by a fan. For its time, it was a wonderful invention, which immediately gave them a huge advantage over other designers and quickly moved them to the target. In his pipe brothers we have experienced more than 200 models of different shapes of profiles. They are made from sheet metal, that they can be bent in various ways. Such a systematic measurement of the resistance values ​​of different surfaces and wing profiles at various angles of attack in the wind tunnel never before Wright brothers was not made up. It is not surprising that the results of these persistent systematic experiments were critical to their continued success.

The main result of these experiments was to determine the so-called center of pressure, that is the resultant of the pressure forces on the wing at different angles of attack. The value of the resultant situation, or the center of pressure, it is essential in the design of airplanes and the calculation of their resistance. Another important result was the definition of wing lift and drag forces at different speeds. The results of their research systematized brothers in special tables, which are then served to them pocket guide. After that, already taking into account the aerodynamic research, they set about designing a new airframe.

1902 Glider third year, unlike the first two, has a vertical tail. The pilot went here in a special cradle cut between the lower plane and sat up on his elbows, his hands ran the front elevator, and movement of the body sideways to mow wire cables ends of the wings. By launching glider, the two men ran off with him to a high mountain against the wind.

The tail was constructed by the fact that the previous two glider tended to rotate around a horizontal axis, and can roll over the wing during torsion. Wright realized that only one wing distortion is impossible to achieve good handling glider. First, the vertical wheel was motionless, but then, when it was discovered that the glider stopped listening wheel is tilted sideways, Orville Wright proposed that the vertical moving wheel. Then, turning it in the direction of the opposite wing, could restore the balance of the cross. Thus was offset by the difference in the resistance lowered and raised wings. Wilber agreed with his brother and supplemented it with the idea of ​​significant improvement: one vertical wheel must be rotated at a time when the warp ends of the wings, it is best to connect the steering wheel and the wings wire cables to operate them simultaneously. Thereafter, the movement of the lever was possible to control the lateral stability. Thus, for the first time in the history of aviation, the Wright brothers used a movable vertical rudder. It was their second great discovery in the way of mastering the element of air.

When Wright was a need to make a turn to the left, he turned the pivot arm; at the same time by means of wire rod rear edge of the right wing (ie outside the bend) fell. Thus, the right wing curved somewhat steeper and rake in more air directed upward. At the same time the left wing inside the bend goes down. As a result of the airplane as a whole tilts into the curve. Right steering lever a, serves to turn, he had a double movement. Directing it forward (pushing away from you), the pilot acted on the double-arm lever K in such a way that the tie rods type shifted turning the wheel to the left. Reverse pulling of the steering lever (on) caused the shifting of steering to the right. On the other hand, the deflection of the left arm and reported the same motion of the rod C, by skewing the thrust wings e: right - bottom, left - up. Distortion of bearing surfaces by avoiding the lever to the right and the left could take place, regardless of how distortion of the rudder (via the lever forward and backward), and together with him.

Distortion of bearing surfaces also helped to preserve the stability of the side in the wind. When a gust of wind bowed the airplane in one direction, the pilot immediately picked up abruptly dropped his wing, reducing at the same time meeting the angle (the angle of the bearing surface to the direction of motion, the higher it is, the greater the resistance, and therefore the lift) in the raised wing. Thus, the airplane straightening roll, fending off a gust of wind. For such a wind counter only required movement of the arm and to the right or to the left.

This transformation of the wings of the plane in the helical surface has been, however, an unintended consequence - the whole glider with several turns around its axis, just as the propeller begins to rotate in translation. In order to equalize this undesirable rotation applied the front surface of the vertical crescent v, and w, fortified between the surfaces of the elevator, which rotates in the direction opposite the movement of the rotary wheel.

The second steering lever controlled flight height. When push-ups it forward control surfaces become flatter, and the glider lowered its nose down.

glider test with the newly established vertical wheel once yielded good results. Planer good to listen to the steering wheel and hovered in the air, sometimes for a whole minute. While nobody in the world can boast such excellent results. We can say that even then sailplane Wright Brothers was the perfect aircraft in the world. He had already all the hallmarks of an airplane: he had two right aerodynamically designed wing, horizontal elevator in front and rear vertical rudder, the ends of the wings for distortion-roll (aileron). The glider was quite manageable - rose up and fell down, turning right and left, without losing stability. In order to become an airplane, glider lacked only one thing - the motor with the propeller.

By building its Wright started at the beginning of 1903. They calculated that they need to fly very easy and a small gasoline engine with a capacity of not less than 8 hp Despite all the efforts they were unable to buy ready-made engine. Then they decided to make it themselves and they sat down for the calculations. Soon, he was ready to draft four-cylinder engine weighing about 90 kg with water cooling and electric ignition. The aluminum case has been made in the local smithy. All other details of the brothers themselves have made in his workshop. Although this work was for them a completely new product, just after the engine assembly to work, and the brothers saw this as a pledge of future success. Another problem in the manufacture of propellers. Of course, no theoretical calculations for the propeller did not exist. After much heated debate and experiments Wright made two wooden screws of pieces of Canadian pine. Each has two blades and is placed on an iron axle. They rotate towards each other and placed behind (rather than in front as it was made later) of each wing. The transfer was carried out with the help of chains. When the engine, transmission and propeller were ready, Wright started the construction of the airplane. The design of it was exactly the same as that of a glider in 1902, but it was made more durable. A pilot, as before, was in a supine position.

Tests of the first airplane were conducted by the ocean in Kitty Hawk (where the brothers have experienced all their gliders). Here, December 14, 1903 Wilbur Wright made the first flight of the engine - it lasted 3 and 5 seconds. Flying 32 meters, the airplane fell. After several attempts to December 17 Wilbur made a longer flight: the airplane was in the air 59 seconds and went 260 m Due to strong winds further flights this year had to be stopped.. The brothers returned to Dayton are very pleased with the results. At first glance, the flight lasted only 59 seconds, it may seem insignificant achievement, but at that time it was a huge victory. Before the Wright brothers even a single unit is heavier than air could not fly is not something that a couple of hundred meters, but just to climb into the air.

Wright immediately began to build a second airplane, which was completed in April 1904, and produced for him a new engine 16 hp Tests conducted on the airplane in Dayton using the airport as a large pasture. To rise into the air, they come up with a special device, which is a tower, the top of which was suspended to a weight of about half a ton. The load was connected by cables to the plane and during its fall created a force that accelerates the rise. The brothers learned to fly, observing extreme caution. Like the first, mastering the glider, they did a lot of take-offs and landings. At the slightest suspicion of danger, they were put on the car. Flying long time passed in a circle at low altitude (about 3 meters). Gradually increased the duration of the flight. In November, an airplane could survive in the air for about 5 minutes and flew up to 5 km. In winter 1905 the third airplane was built with a 20-horsepower engine. In the autumn, having mastered all the secrets of control, Wright embarked on a long flight. October 5 airplane was in the air for as long as the run out of petrol - 38 minutes, and during this time has flown in a circle of 39 km.

However, these records are not received in the United States is no evaluation and remained almost unknown. Moreover - all attempts inventors to interest his government airplane were unsuccessful. The reason for this, however, is very simple - the attention of all journalists and officials was drawn at this time on experiments Langley. After Langley suffered a complete failure, the creation of the airplane seemed a distant dream. It reported that the two mechanical self-taught assembled improvised aircraft designed to be tens of minutes in the air, seemed to be complete nonsense. Issuance of the patent is also delayed for several years. Only the spring of 1906 the patent was finally obtained after long delays. Meanwhile, the construction of airplanes was an unbearable burden for Wright's workshop. In 1905, they were forced by financial difficulties to stop their flights. For three years no one thought about their invention. Only in 1907, clamor raised in France with rumors about their successes, finally drew them to the attention of local officials. In the same year, they received an order for the aircraft from the US Ministry of War, which has paid them for it 100 thousand dollars.

The airplane in 1908 had two seats for the pilot and passenger. In this regard it has been revamped controls. In the same year a new airplane was shown in France and created a furor in Europe. Wilbur Wright jokingly broke all records on it, which had set by the time the French pilots and engineers. October 21, he set an absolute record, held out in the air as much as 1, 5 hours and 31 December beat him with a score of 2 hours 20 minutes. It was a time of triumph Wright. Each of flight attracts thousands of spectators. With bated breath, people were willing to spend hours to monitor the airplane, which is described on the field one right after the other circle. The most famous people were willing to meet with the brothers. Orders for airplanes rained down on them from all sides. In New York, it was founded by the aircraft manufacturer "Wright" with a capital of $ 1 million. Wilbur Wright was elected its chairman. The first factory for the production of airplanes built in Dayton.

But the influence of Wright design ideas on the European continent was not as significant as one might expect at first. Although the "Right" and were at first a distribution, a diagram of the device was soon recognized as insufficiently advanced. It required great skill to manage. Due to the lack of a tail, these airplanes have a dangerous tendency to "nod". Several accidents in 1909 in the "Wright" is clearly shown. The reason was obvious they - Wright planes were not the very "Peno tail", which is required to have implemented their cars French aircraft designers. The role of the tail played raytovskom airplane front elevator operated by hand. Therefore, the slightest delay in this action driving or failure in the steering wheel and it always leads to a loss of balance and threatened to crash, while acting in these cases automatically "Peno tail."

By the time Wright appeared in France, where there was already established aviation school - a few dozen aircraft and installed several high-profile records have been built. However, flying really, these machines still could not and would rather make long jumps. To become a perfect European aircraft airplanes lacked two things - For distortion wings device and perfect shape of the propeller. The greatest success has reached the French designer Voisin. Built in 1907 it commissioned a racing driver Farman airplane "Farman-1" before the Wright brothers was considered the best. This plane Farman established in the same year distance record - 771 meters and was the first to perform the circling. Farman Biplane unlike an airplane the Wright brothers had a tail surface for longitudinal stability Peno system. The tail is significantly relieved airplane management. In addition, Farman aircraft was equipped with a chassis by means of which did run against the wind.

After the French borrowed from Wright's system distortion of the wings and the shape of the screw and their aircraft were all indicators exceed their overseas counterparts. This became evident already at the international competitions in 1909. In general, this was a year of universal triumph of airplanes. Outstanding French aviator Bleriot on his airplane "Blériot-11 'flew across the English Channel. Then Farman created his wonderful airplane "Farman-3" - strong, steady, obedient in management. This aircraft became the main training machine of the time - thousands of pilots from many countries have been on it training course - and one of the first airplanes, which became mass-produced.

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