Flying at supersonic speed. Supersonic aircraft

Consider creating a supersonic passenger aircraft. In his opinion, the liner could be built on the basis of the Tu-160 strategic military bomber.

At the beginning of 2018, Putin already proposed returning to the construction of such aircraft in Russia. However, then experts were skeptical about the president's idea, considering the project too expensive. Later, the Tupolev company said that the new aircraft could make its first flight no earlier than 2027. The cost of all work on the creation of a serial aircraft in the company was estimated at 105 billion rubles.

Info24 talked with aviation experts and found out whether Russia still needs a new supersonic passenger plane.

Disappointing experience

In the history of world aircraft construction, there were two supersonic passenger airliners: the Franco-British Concorde and the Soviet Tu-144. These aircraft could reach speeds of over 2.4 thousand km / h, while the maximum speed of the Airbus A320 is 840 km / h. At the same time, the cost of a flight, for example, from Europe to the United States, reached 7 thousand dollars. Flights were popular with businessmen.

The Tu-144 was developed at the Tupolev Design Bureau in the 1960s. It began to be used in passenger traffic in 1977, but after several accidents, the design bureau decided to freeze the project.

Supersonic passenger aircraft TU-144. Photo: RIA Novosti, wikimedia.org

Around the same time, the French company Aérospatiale and the British BAC developed a joint project called Concorde. A total of 20 supersonic aircraft were produced, which were divided between British Airways and Air France. Over 27 years of regular and charter flights, more than 3 million passengers have used supersonic flights.

On July 5, 2000, one of the Concorde aircraft crashed during takeoff at the Paris Charles de Gaulle airport. Then 113 people died. After that, flights of supersonic aircraft were suspended for a year and a half. In 2003, they were completely stopped due to high fuel prices.

Since then, the world no longer uses supersonic passenger aircraft.

"Not economics, but prestige"

Maxim Pyadushkin, Managing Director of the Aviatransportnoe Obozreniye magazine, told Info24 that the production of supersonic airliners faces not only technical, but also other obstacles.

“The same“ Concorde ”was operated at supersonic only over the Atlantic Ocean, because, for example, in the United States, because of the shock wave, it is forbidden to fly over land at supersonic speeds. These planes had very limited use and the problem has not yet been resolved. The last "Concordes" were delivered practically for nothing, for a symbolic price, there they talked not about economics, but about prestige. But they were also stopped shortly after the accident in Paris, ”Pyadushkin said.

Franco-British supersonic airliner Concorde of British Airways. Photo: Les Chatfield, Flickr

Why does the state need it

Aleksey Sinitskiy, editor-in-chief of the Aviatransportnoe Obozreniye magazine, believes that by developing its own supersonic aircraft, Russia can stimulate the development of other industries.

“In the production of such liners there are a large number of issues that have not been resolved or not yet resolved. Of course, work on these issues is important, necessary and interesting for creating a new generation of highly efficient engines, so work needs to be done. But, in my opinion, this is not a mainstream and not a strategic direction of civil aviation. There are much more mundane issues that, even if they sound less romantic, still need to be addressed. But it is quite another matter if we consider civil aviation as an opportunity to stimulate economic development.

the development of aircraft manufacturing entails improvements in other industries. therefore, it is strategically important for Russia, especially if you do not focus on import substitution, but, for example, find your own areas of specialization and choose areas where it would be possible to offer competitive products on a global scale.

This does not necessarily apply to the whole aircraft, but, for example, to some unit that we would do better than anyone else in the world, ”Sinitsky said in a conversation with Info24.

Although the Concorde planes were sold to airlines at a ridiculous price, the expert does not believe that the money was lost: there was serious research, the industry gained knowledge and technology. In addition, it was one of the first experiments in international cooperation, which subsequently led to a unified system of European aircraft construction.

Unprofitable and inconvenient

At the same time, Sinitsky does not deny that it is extremely difficult to make flights on supersonic airliners payback.

“If the country's leadership needs to improve transport accessibility, then this is one thing. But at the same time, world experience shows that efficiency prevails over speed. The same Concorde program proved that economical flights were in many ways much more in demand, while supersonic flight, due to the generation of a compaction wave under the aircraft, is uneconomical by definition. There are many questions regarding the economy of supersonic transportation, including how convenient it will be for passengers. For example, a flight from Vladivostok to Moscow will be inconvenient in time due to a change in time zones - you will need to either fly out at an inconvenient time, or arrive at an inconvenient arrival. In addition, if you have some comfort in a regular plane, then in a supersonic plane it will be more crowded, ”the expert said.

Image: Info24

The expert of the portal Avia.ru Vladimir Karnozov, however, is sure that it is possible to make flights profitable. True, for this it is "critically important" for them to fly not only across the Atlantic, but also across the Pacific Ocean - for example, from Japan, China and Australia to the USA and Canada.

“It is believed that Concorde was unprofitable, but this is not entirely true. The project turned out to be unprofitable because of the strong opposition from the United States [on environmental standards], which turned out to be effective also because the revenues from the commercial operation of the Concordes were formed mainly from the sale of tickets for flights to airports in New York and other major American cities ... The Concorde flew with stopovers from France to Latin America and from England to the Middle East and further to Southeast Asia, but these routes brought significantly less revenue. As a result of US opposition, the Western European industry produced fewer aircraft than planned, and the program was canceled ahead of schedule, ”said the aviation expert.

For those who talk about free deliveries of Concorde to airlines and base their arguments about the insolvency of the liners on this, Karnozov suggests comparing the cost of the first aircraft and the prices for subsonic airliners of that era. According to him, this is a huge amount of money that the airlines planned to return due to many years of operation on flights from Europe to the United States, where the car worked profitably.

Supersonic aircraft Concorde. Photo: nara.getarchive.net

“If you open foreign aviation publications, then for the last 7-10 years this topic (the creation of supersonic passenger aircraft - approx. Info24) are constantly discussed, mainly in relation to business aircraft. But the problems in the development of such aircraft are not related to technology. It's just that under the influence of the United States, the aviation authorities of the countries of the Western world put forward overestimated requirements for the environmental parameters of "supersonic" (supersonic aircraft, from the English supersonic - supersonic - approx. Info24), in particular - the level of noise on the ground and the magnitude of the sonic boom. There is no way to influence the States, and certification requirements are put forward for the next generation of "supersonics" on their submission. If a solution is not found at the political level, then nothing of the idea of ​​creating a supersonic passenger plane will work. And if the requirements are softened, then a very interesting project will turn out, ”said Karnozov.

He added that the cost of creating such an aircraft is highly dependent on what requirements it will be created for. According to the expert, if the requirements are "reasonable", then the project price will amount to several billion dollars, but if the creation of a supersonic airliner is "adjusted" to the requirements of the United States, then "the budget of tens, or even hundreds of billions of dollars will be insufficient."

Who can fly on such planes

Supersonic flights are extremely expensive - for example, a flight from London to New York can cost $ 7,000. All experts agree that if such flights are in demand, it will be only among businessmen.

“If we are talking about the segment of business transportation, then there may be a demand for speed. But the fuel consumption in such planes will be very high, which is why the cost can be quite high even for wealthy people, ”he said. Info24 Fedor Borisov, leading researcher at the Institute of Transport and Transport Policy, National Research University Higher School of Economics.

Image: Info24

Vladimir Karnozov also agrees with him. According to the expert, supersonic aircraft are needed for "the upper segment, those who fly in business class and first class today."

Attempts to create a new "supersonic"

Maxim Pyadushkin said that there are people and companies that are trying to enter the supersonic aircraft market, but they are focusing on business aviation, and a very limited circle of people will buy their aircraft.

Image: Info24

“Such projects started as startups, enthusiasts gathered to make drawings. But no startup can create an airplane alone. For example, Aerion, supported by Boeing and other major manufacturers. This project is probably the farthest advanced. This gives hope that since large manufacturers have believed in this, the aircraft will be able to bring it to testing, prototype and, in fact, flight, ”said the aviation expert.

On February 6, 1950, during another test, the Soviet jet fighter MiG-17 in horizontal flight exceeded the speed of sound, accelerating to almost 1070 km / h. This turned it into the first mass-produced supersonic aircraft. Developers Mikoyan and Gurevich were clearly proud of their brainchild.

For combat flights, the MiG-17 was considered near-sonic, since its cruising speed did not exceed 861 km / h. But this did not prevent the fighter from becoming one of the most widespread in the world. At various times, he was in service with Germany, China, Korea, Poland, Pakistan and dozens of other countries. This monster even took part in the fighting in the Vietnam War.

The MiG-17 is far from the only representative of the supersonic aircraft genre. We will tell you about a dozen more air liners that also surpassed the sound wave and became famous all over the world.

Bell X-1

The US Air Force specially equipped the Bell X-1 with a rocket engine, as they wanted to use it to study the problems of supersonic flight. On October 14, 1947, the device accelerated to 1541 km / h (Mach 1.26), overcame the predetermined barrier and turned into a star in the sky. Today, the record-breaking model rests in the Smithsonian Museum in the States.

Source: NASA

North American X-15

The North American X-15 is also powered by rocket motors. But, unlike its American counterpart Bell X-1, this aircraft reached a speed of 6167 km / h (Mach 5.58), becoming the first and for 40 years the only manned hypersonic aircraft in the history of mankind (since 1959) who performed suborbital manned space flights. With its help, even the reaction of the atmosphere to the entrance of winged bodies into it was studied. In total, three units of Kh-15 rocket gliders were produced.

Source: NASA

Lockheed SR-71 Blackbird

It is a sin not to use supersonic aircraft for military purposes. Therefore, the US Air Force designed the Lockheed SR-71 Blackbird, a strategic reconnaissance aircraft with a maximum speed of 3,700 km / h (Mach 3.5). The main advantages are fast acceleration and high maneuverability, which allowed him to evade missiles. Also, the SR-71 was the first aircraft to be equipped with technologies for reducing radar signature.

A total of 32 units were built, 12 of which crashed. Removed from service in 1998.

Source: af.mil

MiG-25

We cannot but recall the domestic MiG-25 - a supersonic high-altitude fighter-interceptor of the 3rd generation with a maximum speed of 3000 km / h (Mach 2.83). The plane was so cool that even the Japanese were coveting it. Therefore, on September 6, 1976, Soviet pilot Viktor Belenko had to hijack a MiG-25. After that, over the course of many years in many parts of the Union, planes began to refuel incompletely. The goal is to prevent them from reaching the nearest foreign airport.

Source: Alexey Beltyukov

MiG-31

Soviet scientists did not stop working for the air good of the fatherland. Therefore, in 1968, the design of the MiG-31 began. And on September 16, 1975, he first visited the sky. This two-seater supersonic all-weather long-range interceptor fighter accelerated to a speed of 2500 km / h (Mach 2.35) and became the first fourth generation Soviet combat aircraft.

The MiG-31 is designed to intercept and destroy air targets at extremely low, low, medium and high altitudes, day and night, in simple and difficult weather conditions, with active and passive radar jamming, as well as false thermal targets. Four MiG-31s ​​can control airspace up to 900 kilometers long. This is not an airplane, but the pride of the Union, which is still in service with Russia and Kazakhstan.

Source: Vitaly Kuzmin

Lockheed / Boeing F-22 Raptor

The most expensive supersonic aircraft was built by the Americans. They modeled a fifth-generation multi-role fighter that became the most expensive among their colleagues. The Lockheed / Boeing F-22 Raptor is currently the only fifth-generation fighter in service and the first production fighter with a supersonic cruising speed of 1890 km / h (Mach 1.78). The maximum speed is 2570 km / h (Mach 2.42). Until now, no one has surpassed him in the air.

Source: af.mil

Su-100 / T-4

Su-100 / T-4 ("weaving") was developed as a fighter for aircraft carriers. But the engineers of the Sukhoi Design Bureau managed not only to achieve their goal, but to simulate a cool strike-reconnaissance bomber-missile carrier, which they later wanted to use even as a passenger aircraft and an accelerator for the Spiral aerospace system. The maximum speed of the T-4 is 3200 km / h (Mach 3).

Posted on Tue, 09/29/2015 - 07:20 by russianinterest ...

Original taken from Speed, like a dream. Speed ​​like a vocation

The 1960s can be considered the golden years of supersonic aviation. It was at that time that it seemed that just a little bit more - and squadrons of supersonic aircraft would become the only option for air combat, and supersonic airliners would trace our firmament with their traces, linking all major cities and world capitals. However, it turned out that, as in the case of manned space, a man's hike to high speeds is by no means covered with roses: passenger aircraft still froze at around 800 kilometers per hour, and military aircraft hang out in the area of ​​the sound barrier, occasionally deciding to briefly fly into an area of ​​low supersonic sound, in the region of Mach 2 or slightly more.

What is the reason for this? No, not at all with the fact that "there is no need to fly fast" or "no one needs it." Rather, we are talking about the fact that at some moment the world began to follow the path of least resistance and considered that scientific and technological progress is a self-run cart, which is already going downhill, due to which pushing it additionally is all just an unnecessary waste of extra energy.

Let us ask ourselves a simple question - why is supersonic flight so difficult and costly? Let's start with the fact that when the aircraft overcomes the supersonic barrier, the nature of the flow around the body of the aircraft changes dramatically: the aerodynamic resistance increases sharply, the kinetic heating of the airframe structure increases, and due to the displacement of the aerodynamic focus of the streamlined body, the stability and controllability of the aircraft is lost.

Of course, for a layman and an unprepared reader, all these terms sound rather dull and incomprehensible, but if we summarize all this in the form of one phrase, it will turn out: “it is difficult to fly on supersonic”. But, of course, it is by no means impossible. At the same time, in addition to increasing engine power, the creators of supersonic aircraft have to deliberately change the appearance of the aircraft - characteristic "rapid" straight lines appear in it, sharp corners on the nose and on the leading edges, which immediately distinguishes a supersonic aircraft even outwardly from "smooth "And" sleek "forms of subsonic aircraft.

The nose of the Tu-144 deviated downward during takeoff and landing in order to provide at least a minimal view to the pilots.

In addition, when optimizing an aircraft for supersonic flight, it has another unpleasant feature: it becomes poorly suited for subsonic flight and rather awkward in take-off and landing modes, which it still has to carry out at fairly low speeds. Those very sharp lines and swift shapes that are so good at supersonic succumb to the low speeds at which supersonic aircraft inevitably have to move at the beginning and at the end of their flight. And the sharp noses of supersonic machines still do not give pilots a full view of the runway.

Here, as an example, the bows of two Soviet supersonic aircraft that were not implemented in a series - the M-50 of the Myasishchev Design Bureau (in the background) and the T-4 "object 100" of the Sukhoi Design Bureau (near).

The efforts of the designers are clearly visible: this is either an attempt to reach a compromise in contours, like in the M-50, or a sliding nose, deviating downward, like in the T-4. Interestingly, the T-4 could well become the first serial supersonic aircraft that would fly completely in horizontal supersonic flight without a natural view through the cockpit canopy: at supersonic, the nose cone completely covered the cockpit and all navigation was carried out only by instruments, in addition, the aircraft had optical periscope. The current level of development of navigation and telemetry means, by the way, completely allows us to abandon the complex design of a movable nose cone of a supersonic aircraft - it can already be lifted and landed only by instruments, or even without the participation of pilots at all.

Identical conditions and tasks give rise to similar constructions. The Anglo-French "Concorde" also had a nose slid down during takeoff and landing.

What prevented the USSR from creating already in 1974 an innovative anti-ship warfare complex based on the supersonic T-4, which was so advanced that there were as many as 600 patents in its design?

The thing is that by the mid-1970s, the Sukhoi Design Bureau did not have its own production facilities to conduct extended state tests of the "object 100". For this process, not an experimental, but a serial plant was needed, for the role of which KAPO (Kazan Aviation Plant) was quite suitable. However, as soon as the decree on the preparation of the Kazan Aviation Plant for the assembly of the T-4 pilot batch began to be prepared, Academician Tupolev, realizing that he was losing the serial plant, which produced the "strategic defect carrier" Tu-22, came up with an initiative proposal to create its modification Tu-22M, for which, allegedly, it was only necessary to slightly redesign production. Although, in the future, the Tu-22M was developed as a completely new aircraft, the decision to transfer the Kazan plant to Sukhoi was not made at one time, and the T-4 ended up in a museum in Monino.

Such a big difference between the Tu-22 and Tu-22M is a legacy of the fight against the T-4.

The nose cone issue is not the only compromise supersonic aircraft designers have to make. For many reasons, they end up with both an imperfect supersonic glider and a mediocre subsonic aircraft. Thus, the conquest of new frontiers in speed and altitude by aviation is often associated not only with the use of a more advanced or fundamentally new propulsion system and a new layout of aircraft, but also with changes in their geometry in flight. On the first generation of supersonic aircraft, this option was never implemented, but it was this very idea of ​​a variable sweep wing that eventually became almost canon in the 1970s. Such changes in wing sweep, while improving the characteristics of the aircraft at high speeds, should not have worsened their qualities at low speeds, and vice versa.

The Boeing 2707 was to become the first supersonic passenger aircraft with variable sweep wings.

It is interesting that the fate of the Boeing-2707 was ruined not by its constructive imperfection, but only by a mass of political issues. By 1969, with the Boeing 2707 development program nearing its home stretch, 26 airlines had ordered 122 Model 2707 aircraft from Boeing, valued at nearly $ 5 billion. At that moment, the Boeing program had already left the design and research phase and the construction of two prototypes of model 2707 was started. To complete their construction and manufacture test aircraft, the company needed to attract somewhere between 1-2 billion. 500 aircraft was approaching $ 5 billion. State loans were required. Fundamentally, at another time, Boeing would have found its own funds for this, but the 1960s were not like that.

In the late 1960s, Boeing's production facilities were heavily loaded with the creation of the largest subsonic passenger aircraft in the world, the Boeing 747, which we still fly today. Because of this, model 2707 literally for several years "did not cram" forward from the "air cattle carrier" and ended up behind its kurgozny fuselage. In Vitoge, all available funding and all equipment were used for the production of the 747, and the 2707 was financed by Boeing on a leftover basis.

Two approaches to passenger aviation - Boeing 747 and Boeing 2707 in one picture.

But the difficulties with the creation of 2707 were much more serious than just technical issues or Boeing's production program. Since 1967, the environmental movement against supersonic passenger transport has been growing in the United States. It was argued that their flights would destroy the ozone layer, and the powerful acoustic shock that occurs during supersonic flight was considered unacceptable for populated areas. Pressured by public opinion and then by Congress, President Nixon is setting up a 12-member committee to decide on funding for the SST program, which also included the Boeing 2707. But contrary to his expectations, the commission rejects the need to create an SST not only for environmental, but also for economic reasons. To create the first aircraft, according to their calculations, it was necessary to spend $ 3 billion, which would be paid off only if 300 aircraft were sold. The financial condition of the United States was weakened by the prolonged war in Vietnam and the costs of the moon race.

Work on the 2707 was discontinued in 1971, after which Boeing tried to continue construction on its own for about a year. In addition, private individuals, including students and schoolchildren, also tried to support the "plane of the American Dream", which raised more than a million dollars. But this did not save the program either. As a result, the closure of the program coincided with a recession in the aerospace industry and with the oil crisis, as a result of which Boeing was forced to lay off nearly 70,000 of its employees in Seattle, and the 2707 was dubbed "the plane that ate Seattle."

Goodnight, sweet prince. The cockpit and part of the fuselage "Boeing-2707" in the Hiller Aviation Museum.

What drove the creators of supersonic machines? On the whole, the situation with military customers is clear. Warriors always needed an airplane that would fly higher and faster. The supersonic flight speed made it possible not only to reach the enemy's territory faster, but also to increase the flight ceiling of such an aircraft to an altitude of 20-25 kilometers, which was important for reconnaissance aircraft and bombers. At high speeds, as we remember, the lift of the wing also increases, due to which the flight could take place in a more rarefied atmosphere, and, as a consequence, at a higher altitude.

In the 1960s, until the appearance of anti-aircraft missile systems capable of hitting targets at high altitudes, the main principle of using bombers was to fly to a target at the highest possible altitude and speed. Of course, the current air defense systems close this kind of niche for the use of supersonic aircraft (for example, the S-400 complex can shoot down targets right in space, at an altitude of 185 kilometers and at their own speed of 4.8 km / s, in fact, being a missile defense system , not air defense). However, in operations against ground, surface and air targets, supersonic speed is quite in demand and is still present in promising military plans for both Russian and Western aircraft. It's just that the implementation of a rather complex supersonic flight is difficult to be compatible with the task of stealth and stealth, which they tried to instill in bombers and fighters over the past 30 years, due to which they have to choose, as they say, one thing - either hide or break through.

However, does Russia now have a reliable remedy against the American AUG? So as not to approach them 300 kilometers to launch the Onyx by some inconspicuous but vulnerable vessel? The T-4 had a coherent concept of its own style of destruction of the aircraft carrier group, but does Russia have it now? I think not - just as there are still no X-33 and X-45 hypersonic missiles.

American bomber XB-70 "Valkyrie". It was with them that the MiG-25 was supposed to fight.

Where the future of military aircraft construction will turn is an open question.

I would like to say a few more words about civilian supersonic aircraft.

Their operation made it possible not only to significantly reduce the flight time on long-haul flights, but also to use unloaded airspace at high altitudes (about 18 km), while the main airspace used by liners (altitudes of 9-12 km) was already even in the 1960s. significantly loaded. Also, supersonic aircraft flew on straightened routes (outside airways and corridors). And this is not to mention the elementary: saving the time of ordinary passengers, which was about half of the flight time for, for example, a flight from Europe to the United States.

At the same time, I repeat once again - the project of supersonic aircraft, both military and civil, is by no means impossible from a practical point of view or in any way unrealistic from an economic point of view.

At one time we just turned "the wrong way" and rolled the cart of progress not uphill, but along the easiest and most pleasant way - down and down a slope. Even today, projects for supersonic passenger aircraft are being developed for the same segment for which another innovative concept was made: the Augusta-Westland AW609 tiltrotor. This segment is a segment of business transportation for wealthy clients, when the plane carries not half a thousand passengers in cattle conditions, but a dozen people in conditions of maximum efficiency and maximum comfort. Meet Aerio AS2. If you're lucky, it will fly in the near future, in 2021:

I think that everything is already quite serious there - both the partnership with Airbus and the announced investments of $ 3 billion allow us to consider the project not a “decoy duck”, but a serious application. In short, "a respectable lord is for respectable gentlemen." And not for any rogue who allowed the world at the end of the twentieth century to turn on an easy and convenient path.

However, I already wrote about this, I will not repeat myself. Now it is no more than the past:

Now we live in a different world. In a world without supersonic aviation for everyone. However, this is not the worst loss.

One example of existing projects of supersonic aircraft.

Today I'll start with a short introduction 🙂.

On this site I already have flying aircraft. That is, the time has come long ago to write something and about supersonic, especially since I promised to do it :-). The other day I got down to work with considerable zeal, but realized that the topic was as interesting as it was voluminous.

Recently my articles do not shine with brevity, I do not know whether this is an advantage or a disadvantage :-). And the issue on the topic “ supersonic"Threatened to become even more and it is not known how long I would have had to" create "it :-).

So I decided to try and make a few articles. A kind of small series (about three or four), in which each component will be devoted to one or two concepts on the topic supersonic speeds... And it will be easier for me, and I will bother readers less :-), and Yandex and Google will be more supportive (which is important, you yourself understand :-)). Well, what will come of it to judge, of course, you ..

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So, let's talk today about supersonic and supersonic aircraft... The very concept of “ supersonic"In our language (all the more in a superlative degree) flashes much more often than the term" subsonic ".

On the one hand, this is, in general, understandable. Subsonic aircraft have long become something completely commonplace in our life. A supersonic aircraft, although they have been flying in airspace for 65 years, they still seem to be something special, interesting and deserving of increased attention.

On the other hand, this is quite fair. After all, flights to supersonic- this is, one might say, a separate area of ​​movement closed by a certain barrier. However, inexperienced people may well have a question: “And what, in fact, is so outstanding in this supersound? What difference does it make when an airplane flies at a speed of 400 km / h or 1400 km / h? Give him a more powerful engine and everything will be fine! " At the dawn of its development, aviation was in approximately this semantic position.

Speed ​​has always been the ultimate dream, and initially these aspirations were quite successfully implemented. Already in 1945, test pilot of the firm Messerschmitt L. Hoffmann in horizontal flight on one of the world's first aircraft with jet engines, ME-262, reached a speed of 980 km / h in horizontal flight at an altitude of 7200 m.

However, in reality, everything is far from so simple. After all, the flight to supersonic differs from subsonic not only in the magnitude of the velocity and not so much in it. The difference here is qualitative.

Already at speeds of the order of 400 km / h, such a property of air as compressibility begins to gradually manifest itself. And, in principle, there is nothing unexpected here. Is gas. And all gases, as you know, unlike liquids, are compressible. Compression changes gas parameters, such as density, pressure, temperature. Because of this, different physical processes can proceed in a compressed gas in a different way than in a rarefied one.

The faster the plane flies, the more it, together with its aerodynamic surfaces, becomes like a kind of piston, in a sense, compressing the air in front of it. Exaggerated, of course, but in general it is like that :-).

With an increase in speed, the aerodynamic picture of the flow around the aircraft changes and the faster, the more :-). And on supersonic it is already qualitatively different. At the same time, new concepts of aerodynamics come to the fore, which often simply do not make any sense for low-speed aircraft.

To characterize the flight speed, it now becomes convenient and necessary to use such a parameter as the M number (Mach number, the ratio of the aircraft speed relative to the air at a given point to the speed of sound in the air flow at this point). Another type of aerodynamic drag appears and becomes perceptible (very perceptible!) wave impedance(along with the already increased conventional drag).

Phenomena such as a wave crisis (with a critical number M) become significant supersonic barrier, shock waves and shock waves.

In addition, the controllability and stability characteristics of the aircraft deteriorate due to the rearward displacement of the point of application of aerodynamic forces.

When approaching the region of transonic speeds, the aircraft can experience strong shaking (this was more typical for the first aircraft that stormed the then mysterious boundary of the speed of sound), similar in its manifestations to another very unpleasant phenomenon that aviators had to face in their professional development. This phenomenon is called flutter (topic for another article :-)).

There is such an unpleasant moment as the heating of the air as a result of its sharp braking in front of the aircraft (the so-called kinetic heating), as well as heating as a result of viscous air friction. At the same time, the temperatures are quite high, about 300 ° C. The skin of an aircraft is heated to such temperatures during a long supersonic flight.

We will definitely talk about all the concepts and phenomena mentioned above, as well as the reasons for their occurrence in other articles in more detail. But now so, I think it is quite clear that supersonic- this is something completely different than flying at subsonic (all the more low) speed.

In order to get along with all the newly emerging effects and phenomena at high speeds and fully correspond to its purpose, the aircraft must also change qualitatively. Now it should be supersonic aircraft, that is, an aircraft capable of flying at a speed exceeding the speed of sound in a given section of airspace.

And for him it is not enough just to increase the engine power (although this is also a very important and obligatory detail). These planes usually change their appearance. Sharp corners and edges, straight lines appear in their appearance, in contrast to the "smooth" outlines of subsonic aircraft.

Supersonic aircraft have a swept or triangular wing. A typical and one of the most famous delta wing aircraft is the remarkable MiG-21 fighter (maximum speed at an altitude of 2230 km / h, at sea level 1300 km / h).

Supersonic aircraft with a triangular wing MIG-21.

One of the swept-like options is an ogival wing with an increased lift coefficient. It has a special inflow near the fuselage, designed to form artificial spiral vortices.

MIG-21I with an ogival wing.

MIG-21I - ogival wing.

Live wing TU-144.

It is interesting that a wing of this type, later installed on the TU-144, was tested on a flying laboratory based on the same MIG-21 (MIG-21I).

The second option is supercritical wing... It has a flattened profile with a curved rear end in a certain way, which makes it possible to postpone the occurrence of a wave crisis at high speeds and can be beneficial in terms of economy for high-speed subsonic aircraft. Such a wing is used, in particular, on the SuperJet 100 aircraft.

SuperJet 100. An example of a supercritical wing. The bend of the profile is clearly visible (back)

Photos are clickable.