What hypersonic speed? Hypersound

HYPERSOUND

Where else is there a niche for the application of aviation technologies, i.e., the implementation of controlled flight within the earth’s atmosphere? This niche is hypersound, that is, flight at speeds four or more (up to six) times the speed of sound. Like all technologies, hypersonic technology is dual-purpose, i.e. a hypersonic aircraft can be used for both civil and military purposes. Moreover, the region of hypersonic speeds can also be used for the operation of aerospace aircraft.

In the 1970-1980s, in an era of technical optimism, projects for aerospace aircraft with horizontal takeoff and landing were developed in Europe. These projects were direct competition with the American Space Shuttle, a reusable spacecraft. The Shuttle, as you know, launches vertically with the help of a powerful rocket booster and, after completing its mission, lands like an airplane. In the UK, the project of such a shuttle aircraft was called “HOTOL” (Horizontal Take-Off Landing). Obviously, using an air-breathing engine as the first stage would significantly increase the efficiency of the system as a whole.

In this case, acceleration in the layers of the atmosphere would occur using oxygen from the atmosphere itself during combustion, and not stored in the rocket tanks.

While HOTOL was an all-rocket aircraft project, in the then Federal Republic of Germany the aerospace aircraft project involved the use of a jet engine in the first stage. This device was named “Sänger” in honor of the famous German scientist and engineer Eugen Sänger, who actively worked in the 1930-1940s. in Germany on the creation of rocket and ramjet engines. Then, in the 1980s, it seemed that the creation of aerospace systems was quite possible. Most likely, technically it was so. But these promising projects were never implemented due to the high cost of development, which was beyond the budget of one country. Nevertheless, today there is a possibility of returning to these projects on the basis of international cooperation and an appropriate division of labor. Now, after the completion of the conceptually very controversial American shuttle program, it is time to begin creating such a system. In any case, to broaden your horizons it is useful to know the scheme for launching a spacecraft into low-Earth orbit using aviation technologies.

As an example, let us first consider the operating diagram of the Zenger aerospace aircraft. This is a two-stage apparatus: the first stage is a hypersonic aircraft with a turbo-direct-flow power plant running on hydrogen, the second stage is a rocket with a liquid hydrogen-oxygen rocket engine. The Zenger takes off like an airplane using the thrust of conventional turbojet engines. Just like an airplane, it gains an altitude of 11 km at subsonic speed. At this point of the trajectory (H=11 km, M=0.8) the aircraft can perform a long cruising flight (1st cruising flight mode). Next, acceleration begins to Mach 3.5 with an altitude climb of up to 20 km. At this point in the trajectory, the turbojet engine is turned off and hooded, and the ramjet circuit is turned on instead. There is one more point on the trajectory (2nd cruising mode), the flight parameters at which also ensure a long cruising flight (H=25 km, M=4.5) of the aircraft. Finally, upon reaching an altitude of 30 km and a flight speed corresponding to a flight Mach number of 6.8, the second rocket stage separates and launches. As we see, this stage has already been accelerated to high speed and, therefore, to enter low-Earth orbit, the second-stage rocket will require a significantly smaller supply of energy (fuel) than in the case of a purely rocket launch from the surface of the earth.

Let us recall that the use of hydrocarbon fuel (kerosene) in hypersound is limited to the level of Mach number = 4 due to the low flame temperature compared to hydrogen. Because of this limitation, with increasing flight speed and increasing kinetic heating of the air at the inlet during its braking, the amount of heat supplied decreases and, accordingly, the work done and thermal efficiency decrease (remember Carnot’s formula). Therefore, to achieve effective conversion of chemical energy of fuel into work, it is necessary to use fuel with more high temperature combustion flame. Hydrogen has exactly this quality, but it also has speed restrictions, namely Mmax = 7. An alternative to this is the technology... cooling the air at the engine inlet using a heat exchanger-recuperator using the cooling resource stored in fuel tanks (liquid hydrogen, which has a low temperature ).

Theoretical developments of hypersonic passenger plane were made at NASA (USA) back in the 1970s. It was planned to create an “Orient Express” aircraft capable of covering the distance from New York to Tokyo in three (!) hours. This aircraft was designed to carry 300 passengers over a distance of 12,000 km with a cruising speed of M=5. The aircraft, with a take-off weight of 440 tons, was to be equipped with four engines of 27.5 tons of thrust each (power ratio - the same classic 0.25 for four-engine aircraft). In 1989, an international project was launched to develop technologies for the power plant of a promising hypersonic passenger aircraft. Japan was chosen as the base country for the integration of the engine project, with the participation of the world's leading developers of gas turbine engines, Rolls-Royce and General Electric. The project went on smoothly for twenty years, experiments were carried out on individual components of the future turbo-ramjet engine, but the result has not yet been achieved.

The Europeans did not lag behind the United States: already at the beginning of the 21st century, projects of hypersonic passenger aircraft for 200 (300 tons of take-off weight) and 300 (400 tons of take-off weight) passengers on the planned Brussels-Sydney route also appeared here. The future hypersonic aircraft must cover this distance in three hours. How realistic are these projects? From the point of view of economic efficiency, a passenger hypersonic aircraft seems to be a very risky project. Huge investments in development are unlikely to pay off in its expensive operation. If only... on the future crowded Beijing-New York route.

But the military and space use of hypersound is completely real, and here the United States is ahead of everyone, at least in terms of well-thought-out strategy. Moreover, NASA and the US Military Department created a joint organizational structure, called the National Aerospace Initiative (NAI), for the practical implementation of the next generation of projects. Having suffered with the shuttles in terms of predicting their reliability during repeated use, NASA has set the task of radically reducing the costs of spacecraft launches by developing a new generation of launch vehicles using hypersonic aircraft. This aerospace aircraft project, designated X-43 (like any prototype aircraft designated “X”), is scheduled to be completed by 2025 with flight tests of the demonstrator. True, the final choice of the type of first stage has not yet been made. Both options are being considered: purely rocket and based on a gas turbine engine. But the “upper” part of the first stage is a hypersonic ramjet engine with supersonic combustion.

In general, the natural transformation of the optimal spacecraft engine looks like this. At launch, when the initial flight speed in the atmosphere is zero, the air compression necessary to produce work is carried out by the compressor of the gas turbine engine. As the flight speed increases, more and more compression occurs when air is decelerated in the air intake and less and less occurs in the compressor. Starting from a flight Mach number of 3–3.5, the compressor essentially degenerates, adding virtually nothing to the compression ratio in the air intake. Here it is advisable to turn off the gas turbine part of the engine and switch to a purely direct-flow circuit with subsonic combustion up to flight speeds of the order of M = 5. The next optimal modification of the engine is a direct-flow engine with supersonic combustion (at M4, the stagnation temperature when flowing around the stabilizer reaches the ignition value, and stable combustion occurs at high, including supersonic, speeds). And finally, when leaving the atmosphere, where air has low density and cannot serve as a working fluid, liquid is used rocket engine, which uses its own supply of oxidizer in the tank of a rocket or aircraft instead of atmospheric air. The required pressure in the combustion chamber is ensured by the flow of the working fluid, which, in turn, is provided by pumps pumping the oxidizer and fuel in the required quantity.

While gas turbine technologies up to the flight Mach number of 3 are well developed, the area of ​​operation of a ramjet engine with supersonic combustion (M4) is problematic both scientifically and practically. And intensive research is being conducted in this direction. In addition, it seems tempting to extend the scope of application of a gas turbine engine (albeit in a combined version with a direct-flow engine) to M = 4. Then in spaceship the power plant for its acceleration will have three separate modules: turbo ramjet, ramjet with supersonic combustion and rocket engines.

The USA has adopted a corresponding program for the development of the so-called “Revolutionary Turbine Accelerator” (RTU or, in English transcription, RTA), in which the famous company General Electric participates. The prototype of such a “revolutionary” engine is the F-120, a so-called “variable cycle engine” with mechanically adjustable flow areas (in particular, the turbine nozzle apparatus).

There are many problems in creating a hypersonic aircraft. Starting from the insufficient accuracy of forecasting the external resistance of such a device, and consequently, the assessment of the required amount of thrust of the power plant. The fact is that at such hypersonic speeds, the reliability of geometric modeling during aerodynamic blowing still requires confirmation. It is unclear whether the similarity theory, so successfully used in the study of subsonic and supersonic (but not hypersonic) aircraft models, works (most likely does not work) in this case. Modern methods calculations and modeling of aerodynamics also need verification. The interaction of the hypersonic flow with the engine and the aircraft gives rise to significantly nonlinear effects that modern grid-based mathematical modeling methods cannot accurately describe. Everything is leading to the fact that the development of such expensive systems should largely be carried out on location in flight conditions. Here we are in a situation similar to the initial stage of development of large rocket engines.

The ramjet circuit of a supersonic combustion engine also requires research, ranging from the development of new, lighter heat-conducting materials such as gamma-titanium-aluminum or silicon-based ceramic composites and the choice of fuel type. It must be borne in mind that fuel is used here to cool the combustion chamber. Etc.

What is the situation with hypersound in Russia? And what is the possible use of hypersonic aircraft here? One should hardly expect the use of hypersound to launch spacecraft and ships into orbit. Russia has long had a reliable system for using rocket launch vehicles for this purpose. There will be no hypersonic in Russia air transport- There is no such need, and from an economic point of view it is inappropriate. But in the field of military use of hypersound there are tempting prospects. It should be noted that this topic has been studied in Russia for a long time (since the 1970s) at the Central Institute of Aviation Engine Engineering within the framework of federal targeted programs(“Cold” on the use of hydrogen, etc.). This topic not only provides excellent opportunities for development fundamental science, primarily in the field of fluid and gas mechanics, as well as combustion physics, but also has an obvious applied nature. Developing new mathematical models of processes, conducting unique experiments - all this in itself is of great value for innovative development countries. In the case of the creation of a hypersonic weapons carrier, the country’s defense receives a new quality due to increased reaction speed and invulnerability of the response to possible threats.

At CIAM, the topic of scramjet (hypersonic ramjet engine) began to be substantively studied in 1985 (department 012, department head A.S. Rudakov), focusing on the creation of an aerospace aircraft. The concept of such an aircraft was developed at the Tupolev Design Bureau, and future project The aircraft was designated Tu-2000. But it was not possible to organize systematic work to create such an aircraft for many reasons, including the lack of targeted funding. As you know, “perestroika” began, and Mamai “went through this “perestroika” on many projects. Nevertheless, the Cold program planned to conduct a flight experiment of a scramjet engine, designated S-57. This work was complex in nature: it was necessary to prepare a hypersonic flying laboratory based on the S-200 anti-aircraft missile, develop a launch complex, create the scramjet itself and a fuel supply control system, on-board system storage and supply of liquid hydrogen, filling and transport complex liquid hydrogen, etc.

The scramjet engine itself technical specifications CIAM was developed (with the participation of the Tushino Motor Design Bureau) in the famous Voronezh Design Bureau "Khimavtomatika" (founder - S.A. Kosberg), which developed liquid rocket engines both for space and for V. Chelomey's combat missiles. The engine had an axisymmetric air intake and was installed in the head of the rocket. TsAGI carried out aerodynamic purging of the air intake and the S-200 rocket. The Cryogenmash enterprise has developed an on-board hydrogen storage system. The flying laboratory, naturally, was created by the developers of the S-200. Organizations of the Ministry of Defense took an active part in the project - the tests were planned to be carried out at the Sary-Shagan training ground (Kazakhstan).

The Russian scramjet entered the flight experiment earlier than the American one. Already in 1991, the first flight was carried out with the launch of a scramjet lasting 27.5 seconds with automatic switching on and off of the combustion chamber. It was a major success, despite the burnout of the combustion chamber. But in 1992... funding for this program stopped: we all remember well that time of “liberal” reforms. Money was found in France in exchange for information, and at the end of 1992, a second, even more successful test of the S-57 was carried out, during which the engine operated for 40 seconds, including more than 20 seconds in supersonic combustion mode in the chamber. French engineers were also present during the testing.

In 1994, the Americans (NASA) also joined this program - it was very tempting to use ready-made infrastructure and a research object. NASA has awarded a contract to participate in this experiment with appropriate funding. The goal of the test was to achieve a flight speed corresponding to Mach number = 6.5 and demonstrate stable operation of the scramjet engine. In connection with this requirement, the scramjet was modified, including an improved combustion chamber cooling system, and on February 12, 1998, a flight test of the scramjet was successfully carried out. The engine worked without destruction for the required 70 seconds and the maximum specified speed was achieved. It should be noted that the American X-43 scramjet made its first hypersonic flight in 2001, reaching a speed of M=6.8. Despite the obvious success of the Russian experiment, many problems remained unresolved. And one of the main ones is determining the real external resistance of the aircraft. This requires autonomous (without a rocket “booster”) flight.

Tu-2000 hypersonic aircraft project.

What's next? The Americans went their own way, implementing a large-scale “road map” called “Hypersonic Access to Space” with completion in 2025. They have nowhere to go - the “shuttles” should be written off as soon as possible, and there is nothing to fly into space. One would think that after two space shuttle disasters, the director of NASA should have been baptized before signing permission for the next flight. Russia did not have the money, or rather, the understanding in the country’s leadership, to force such a truly innovative topic. But France, too, due to poverty, “hooked” on Russia: the experimental hypersonic aircraft LEA with a length of 4.2 meters is planned to be tested using Russian system output to calculated flight parameters. The device itself is a classic airplane with a “flat” air intake and nozzle. The lower surfaces of this aircraft are simultaneously the external surfaces of flow deceleration in the front part and its expansion after heat is added in the rear part. The contract (2006) is supported by Rosoboronexport on the Russian side. Among the Russian participants are the Raduga enterprise (rocket booster), TsAGI (aerodynamic blowers), Flight Research Institute named after. Gromov (telemetry), CIAM and Moscow Aviation Institute (testing of combustion processes and mathematical modeling of processes).

Diagram of a hypersonic ramjet engine with supersonic combustion at M›4. Retractable (when operating at hypersonic) flame stabilizers are visible.

Planned for 2013...2015. perform four flights lasting 30–40 seconds in the hypersonic speed range M = 4–8 at an altitude of 30–40 km. The launch to the design flight parameters must be carried out sequentially using the Tu-22MZ supersonic bomber (“booster” + LEA), then the “booster” rocket with the device must be separated from the aircraft, and with its help the device must be launched to the design altitude at which it will make a horizontal flight. As a result of these tests it is planned to obtain key information both about the properties of a hypersonic aircraft and about the combustion and cooling processes in the engine. We wish this project success. Everything is fine, but if it weren’t for Oboronprom with its unbridled desire to earn money without reliable and, as it seems to officials, too expensive engineering support.

This week, the third test flight of the American hypersonic aircraft (HLA) X-51 AWaveRider, a prototype of a promising missile, took place. However, 15 seconds after launch, even before the main engine began to operate, WaveRider lost control and fell into the ocean.

The previous test, which took place last year, also failed - the accelerator, which accelerates the device to the speed required to start the main engine, did not work in time and did not separate. However, earlier, in 2010, the engine of the “machine” managed to operate for 200 seconds (300 were planned), accelerating the device to five speeds of sound (5M). Its duration of operation thus tripled the previous record set by the Russian/Soviet hypersonic flying laboratory (HFL) Kholod. At the same time, unlike the domestic device, the “American” used aviation kerosene rather than hydrogen as fuel.

The current failure will certainly slow down the US hypersonic program, for which $2 billion has been spent. However, this does not change the fact that the United States already has a key technology for this program - a working prototype of a hypersonic air-breathing engine (scramjet, aka scramjet).

Potentially, such engines are capable of accelerating an aircraft to 17 speeds of sound on hydrogen and up to 8 on hydrocarbon fuel. However, for it to work, it is necessary to achieve stable combustion of fuel in a supersonic air flow - which, according to one of the developers, is no easier than keeping a match lit in the epicenter of a hurricane. However, not so long ago it was believed that this was impossible in principle when using hydrocarbon fuel, and the only suitable fuel for scramjet engines was explosive hydrogen, which creates operational difficulties and “inflates” the volume of fuel tanks due to its low density. However, since 2004, a number of relatively successful tests have been carried out in the West. aircraft- both hydrogen and kerosene.

What is the practical meaning of the two billion dollar program? The design speed of the X-51 is 7M (about 7 thousand km/h for an altitude of 20 km), the design range is 1600 km, the flight altitude is about 25 km. In other words, in terms of “range” it approximately corresponds to the BGM-109 Tomohawk cruise missile (1600 km, with a nuclear warhead - 2500 km) or a medium-range ballistic missile - for example, withdrawn from service under the Pershing-2 INF Treaty ( 1770 km). What are the advantages of the "waveship" compared to its "competitors"?

BGM-109 has a subsonic speed of 880 km/h. Thus, the flight to the maximum range takes about two hours. During this time, the missile can be detected and destroyed, and the target can move. Of course, a cruise missile flying at an altitude of about 60 m above the ground and having low radar signature due to its size alone is a very problematic target for air defense. However, it is also known successful examples defense of attacked objects from Tomahawks - for example, the Iraqi nuclear center during Desert Storm.

A ballistic missile with a range of the same order of magnitude has average speed about 10 thousand km/h. However, firstly, “ballistics” can be detected from space already at the moment of launch - an impressive torch from working rocket engines is quite clearly visible. Secondly, the maximum altitude of the trajectory of ballistic missiles of this range is close to 400 km, so they show up on missile defense radars quite early. Thirdly, “ballistics” are a non-maneuvering target, which makes it possible to intercept them even by anti-aircraft missiles aimed at the lead point. In general, with modern development missile defense systems, a medium-range ballistic missile is a fairly vulnerable target.

At the same time, ballistic missiles are a phenomenally inefficient means of delivery in terms of the ratio of launch mass to payload. Chemical rocket engines combine enormous thrust with even more monstrous gluttony, and ballistic flights are, in principle, energy-consuming. As a result, for example, the Pershing 2, with a launch weight of 7.4 tons, carried a warhead of 399 kg. For comparison, Tomahawks carry almost the same amount with their own weight of about one and a half tons.

Now let's compare it with hypersonic missiles. The speed and flight time are generally comparable to those of the Pershing 2. At the same time, the X-51, firstly, uses a much more economical air-jet engine. Secondly, it does not climb to a height of 400 km, “reporting” its presence to all surrounding missile defense radars. Thirdly, it is able to actively maneuver. Note that, as tests carried out in 2007 by the Swedish SaabBofors showed, at speeds of 5.5 M, complex maneuvers are possible even in dense layers of the atmosphere. As a result, intercepting a WaveRider is only possible if the interceptor is noticeably superior to the latter in speed and maneuverability. Now there are simply no such interceptors.

Existing missile defense systems are also unable to combat X-51 class hypersonic missiles. Moreover, even in the case of a fundamental possibility of destruction, the high speed of the target sharply reduces the interception zone.

In other words, WaveRider combines a flight time comparable to medium-range ballistic missiles with much lower visibility and virtual invulnerability against modern air defense/missile defense. Meanwhile, at one time the leadership of the USSR went to great lengths to remove the Pershings from Europe, exchanging them for much more large quantity its own medium-range missiles - and for good reason. The 8-10 minute flight time of American missiles turned them into an almost ideal means of disarming and “decapitating” strike - those under attack simply had no time left to respond. If the Kh-51 is brought into series production, the situation will be reproduced in a worse version - despite the fact that the creation of nuclear variants of “waveships” is quite possible.

At the same time, the use of scramjet engines is not limited to medium-range vehicles. On the one hand, according to the NATO Advisory Group on Space Research and Development (AGARD), scrumjets can be widely used in purely tactical short-range systems - these are anti-tank missiles (also designed to destroy fortifications), air-to-air missiles and small-caliber ( 30-40 mm) shells for hitting air targets. Another probable direction is the use of scramjet engines in anti-missiles designed to intercept ballistic missiles in the initial part of the trajectory.

On the other hand, the use of hypersonic technologies can lead to the emergence of fundamentally new classes of strategic systems. The most conservative option is to use hypersonic vehicles as “maneuvering warheads” for traditional ballistic missiles.

Note that a long-range ballistic missile is slightly vulnerable in the middle section of the trajectory (since it is surrounded by a huge number of light decoys, dipole reflectors and jammers), but is vulnerable in the initial and final sections of the trajectory (light decoys are eliminated by the atmosphere itself, as a result the warhead is accompanied only by a small amount of heavy LC). At the same time, both the warhead and its “retinue” represent a set of non-maneuvering ballistic targets, which radically simplifies the missile defense task. However, a high-speed and maneuverable “machine” with a scramjet engine is practically invulnerable to current air defense and missile defense systems. As a result, by combining a classic ICBM with a hypersonic maneuvering warhead, it is possible to achieve a reliable breakthrough of the corresponding echelon of missile defense.

In other words, we are talking about technology that can truly revolutionize military affairs. The hypersonic threat will inevitably become a reality in the very foreseeable future.

A typical passenger plane flies at a speed of about 900 km/h. A military fighter jet can reach approximately three times the speed. However, modern engineers from the Russian Federation and other countries of the world are actively developing even faster machines - hypersonic aircraft. What are the specifics of the relevant concepts?

Criteria for a hypersonic aircraft

What is a hypersonic aircraft? This is usually understood as a device capable of flying at a speed many times higher than that of sound. Researchers' approaches to determining its specific indicator vary. A common methodology is that an aircraft should be considered hypersonic if it is a multiple of the speed indicators of the fastest modern supersonic vehicles. Which are about 3-4 thousand km/h. That is, a hypersonic aircraft, if you adhere to this methodology, must reach a speed of 6 thousand km/h.

Unmanned and controlled vehicles

The approaches of researchers may also differ in terms of determining the criteria for classifying a particular device as an aircraft. There is a version that only those machines that are controlled by a person can be classified as such. There is a point of view according to which an unmanned vehicle can also be considered an aircraft. Therefore, some analysts classify machines of the type in question into those that are subject to human control and those that function autonomously. Such a division may be justified, since unmanned vehicles can have much more impressive technical characteristics, for example, in terms of overload and speed.

At the same time, many researchers consider hypersonic aircraft as a single concept for which key indicator- speed. It doesn’t matter whether a person sits at the helm of the device or the machine is controlled by a robot - the main thing is that the plane is fast enough.

Take off - independently or with outside help?

There is a widespread classification of hypersonic aircraft, which is based on classifying them into the category of those that are capable of taking off on their own, or those that require placement on a more powerful carrier - a rocket or a cargo plane. There is a point of view according to which it is right to include mainly those that are capable of taking off independently or with minimal involvement of other types of equipment as devices of the type under consideration. However, those researchers who believe that the main criterion characterizing a hypersonic aircraft, speed, should be paramount in any classification. Whether the aircraft is classified as unmanned, controlled, capable of taking off on its own or with the help of other machines - if the corresponding indicator reaches the above values, then it means that we are talking about a hypersonic aircraft.

Main problems of hypersonic solutions

The concepts of hypersonic solutions are many decades old. Throughout the years of development of the corresponding type of devices, world engineers have been solving a number of significant problems that objectively prevent the production of “hypersonics” from being put into production - similar to organizing the production of turboprop aircraft.

The main difficulty in designing hypersonic aircraft is creating an engine that can be sufficiently energy efficient. Another problem is lining up the necessary apparatus. The fact is that the speed of a hypersonic aircraft in the values ​​​​that we discussed above implies strong heating of the body due to friction with the atmosphere.

Today we will look at several examples of successful prototypes of aircraft of the corresponding type, the developers of which were able to make significant progress in successfully solving the noted problems. Let us now study the most famous world developments in terms of creating hypersonic aircraft of this type.

from Boeing

The fastest hypersonic aircraft in the world, according to some experts, is the American Boeing X-43A. Thus, during testing of this device, it was recorded that it reached speeds exceeding 11 thousand km/h. That is approximately 9.6 times faster

What is especially remarkable about the X-43A hypersonic aircraft? The characteristics of this aircraft are as follows:

The maximum speed recorded in tests is 11,230 km/h;

Wingspan - 1.5 m;

Body length - 3.6 m;

Engine - direct-flow, Supersonic Combustion Ramjet;

Fuel - atmospheric oxygen, hydrogen.

It can be noted that the device in question is one of the most environmentally friendly. The fact is that the fuel used practically does not emit harmful combustion products.

The X-43A hypersonic aircraft was developed jointly by NASA engineers, as well as Orbical Science Corporation and Minocraft. was created about 10 years ago. About $250 million was invested in its development. The conceptual novelty of the aircraft in question is that it was conceived for the purpose of testing latest technology ensuring the operation of motor traction.

Development from Orbital Science

The Orbital Science company, which, as we noted above, took part in the creation of the X-43A, also managed to create its own hypersonic aircraft - the X-34.

Its top speed is more than 12 thousand km/h. True, during practical tests it was not achieved - moreover, it was not possible to achieve the indicator shown by the X43-A aircraft. The aircraft in question is accelerated when the Pegasus rocket, which operates on solid fuel, is activated. The X-34 was first tested in 2001. The aircraft in question is significantly larger than the Boeing aircraft - its length is 17.78 m, its wingspan is 8.85 m. The maximum flight altitude of the hypersonic vehicle from Orbical Science is 75 kilometers.

Aircraft from North American

Another famous hypersonic aircraft is the X-15, produced by North American. Analysts classify this apparatus as experimental.

It is equipped, which gives some experts a reason not to classify it, in fact, as an aircraft. However, the presence of rocket engines allows the device, in particular, to perform So, during one of the tests in this mode, it was tested by pilots. The purpose of the X-15 device is to study the specifics of hypersonic flights, evaluate certain design solutions, new materials, and control features of such machines in various layers of the atmosphere. It is noteworthy that it was approved back in 1954. The X-15 flies at a speed of more than 7 thousand km/hour. Its flight range is more than 500 km, its altitude exceeds 100 km.

The fastest production aircraft

The hypersonic vehicles we studied above actually belong to the research category. It will be useful to consider some production models of aircraft that are close in characteristics to hypersonic ones or are (according to one methodology or another) hypersonic ones.

Among such machines is the American development of the SR-71. Some researchers are not inclined to classify this aircraft as hypersonic, since its maximum speed is about 3.7 thousand km/h. Among its most notable characteristics are: take-off weight, which exceeds 77 tons. The length of the device is more than 23 m, the wingspan is more than 13 m.

The Russian MiG-25 is considered one of the fastest military aircraft. The device can reach speeds of more than 3.3 thousand km/h. Maximum take-off weight Russian plane- 41 tons.

Thus, in the market for serial solutions with characteristics close to hypersonic ones, the Russian Federation is among the leaders. But what can be said about Russian developments regarding “classical” hypersonic aircraft? Are engineers from the Russian Federation capable of creating a solution that is competitive with machines from Boeing and Orbital Scence?

Russian hypersonic vehicles

At the moment, the Russian hypersonic aircraft is under development. But it is going quite actively. We are talking about the Yu-71 aircraft. Its first tests, judging by media reports, were carried out in February 2015 near Orenburg.

It is assumed that the aircraft will be used for military purposes. Thus, a hypersonic vehicle will be able, if necessary, to deliver destructive weapons over considerable distances, monitor the territory, and also be used as an element attack aircraft. Some researchers believe that in 2020-2025. The Strategic Missile Forces will receive about 20 aircraft of the corresponding type.

There is information in the media that the Russian hypersonic aircraft in question will be mounted on the Sarmat ballistic missile, which is also at the design stage. Some analysts believe that the Yu-71 hypersonic vehicle being developed is nothing more than a warhead that will have to be separated from the ballistic missile at the final stage of flight and then, thanks to the high maneuverability characteristic of the aircraft, overcome missile defense systems.

Project "Ajax"

Among the most notable projects related to the development of hypersonic aircraft is Ajax. Let's study it in more detail. The Ajax hypersonic aircraft is a conceptual development of Soviet engineers. In the scientific community, conversations about it began back in the 80s. Among the most notable characteristics is the presence of a thermal protection system, which is designed to protect the case from overheating. Thus, the developers of the Ajax apparatus proposed a solution to one of the “hypersonic” problems we identified above.

The traditional thermal protection scheme for aircraft involves placing special materials on the body. The Ajax developers proposed a different concept, according to which it was not supposed to protect the device from external heat, but to let heat inside the machine, while simultaneously increasing its energy resource. The main competitor of the Soviet aircraft was considered to be the hypersonic aircraft “Aurora”, created in the USA. However, due to the fact that designers from the USSR significantly expanded the capabilities of the concept, new development was entrusted with the most wide circle tasks, in particular research ones. We can say that the Ajax is a hypersonic multi-purpose aircraft.

Let's take a closer look at the technological innovations proposed by engineers from the USSR.

So, the Soviet developers of Ajax proposed using the heat generated as a result of friction of the aircraft body with the atmosphere and converting it into useful energy. Technically, this could be realized by placing additional shells on the device. As a result, something like a second corps was formed. Its cavity was supposed to be filled with some kind of catalyst, for example, a mixture of flammable material and water. The heat-insulating layer made of solid material in Ajax was supposed to be replaced with a liquid one, which, on the one hand, was supposed to protect the engine, on the other, would promote a catalytic reaction, which, meanwhile, could be accompanied by an endothermic effect - the movement of heat from the outside body parts inward. Theoretically, the cooling of the external parts of the device could be anything. The excess heat, in turn, was supposed to be used to increase the efficiency of the aircraft engine. At the same time, this technology would make it possible to generate free hydrogen as a result of the reaction of the fuel.

At the moment, there is no information available to the general public about the continuation of the development of Ajax, however, researchers consider the implementation of Soviet concepts into practice to be very promising.

Chinese hypersonic vehicles

China is becoming a competitor to Russia and the United States in the hypersonic solutions market. Among the most famous developments of engineers from China is the WU-14 aircraft. It is a hypersonic controlled glider mounted on a ballistic missile.

An ICBM launches an aircraft into space, from where the vehicle sharply dives down, developing hypersonic speed. The Chinese device can be mounted on various ICBMs with a range from 2 to 12 thousand km. It was found that during tests, the WU-14 was able to reach a speed exceeding 12 thousand km/h, thus becoming the fastest hypersonic aircraft according to some analysts.

At the same time, many researchers believe that it is not entirely legitimate to classify the Chinese development as an aircraft. Thus, there is a widespread version according to which the device should be classified specifically as a warhead. And very effective. When flying downward at the marked speed, even the most modern systems A missile defense system will not be able to guarantee interception of the corresponding target.

It can be noted that Russia and the United States are also developing hypersonic vehicles used for military purposes. At the same time, the Russian concept, according to which it is supposed to create machines of the appropriate type, differs significantly, as evidenced by data in some media, from the technological principles implemented by the Americans and the Chinese. Thus, developers from the Russian Federation are concentrating their efforts in the field of creating aircraft equipped with a ramjet engine that can be launched from the ground. Russia plans to cooperate in this direction with India. Hypersonic vehicles created according to the Russian concept, according to some analysts, are characterized by lower cost and a wider range of applications.

At the same time, the Russian hypersonic aircraft, which we mentioned above (Yu-71), suggests, as some analysts believe, deployment on ICBMs. If this thesis turns out to be correct, then we can say that engineers from the Russian Federation are working simultaneously in two popular conceptual directions in the construction of hypersonic aircraft.

Summary

So, probably the fastest hypersonic aircraft in the world, if we talk about aircraft regardless of their classification, is still the Chinese WU-14. Although you need to understand that real information about it, including those related to tests, may be classified. This is quite consistent with the principles of Chinese developers, who often strive to keep their military technologies secret at all costs. The speed of the fastest hypersonic aircraft is more than 12 thousand km/h. The American development of the X-43A is “catching up” with it - many experts consider it to be the fastest. Theoretically, the hypersonic aircraft X-43A, as well as the Chinese WU-14, can catch up with the development from Orbical Science, designed for a speed of more than 12 thousand km/h.

The characteristics of the Russian Yu-71 aircraft are not yet known to the general public. It is quite possible that they will be close to the parameters of the Chinese aircraft. Russian engineers are also developing a hypersonic aircraft capable of taking off independently, rather than based on an ICBM.

Current projects of researchers from Russia, China and the United States are in one way or another related to the military sphere. Hypersonic aircraft, regardless of their possible classification, are considered primarily as carriers of weapons, most likely nuclear. However, in the works of researchers from different countries of the world there are theses that “hypersonic”, like nuclear technologies, may well be peaceful.

The issue is the emergence of affordable and reliable solutions that make it possible to organize mass production of machines of the appropriate type. The use of such devices is possible in the widest range of sectors of economic development. Hypersonic aircraft are likely to find greatest demand in the space and research industries.

As production technologies for the corresponding machines become cheaper, people may begin to show interest in investing in such projects. transport businesses. Industrial corporations and providers of various services may begin to consider “hypersonic” as a tool for increasing business competitiveness in terms of organizing international communications.

There was an ordinary ballistic missile, but it became a “hypersonic” one. Will it fly better, further and faster? And in general, how much more dangerous are “hypersonic” weapons than conventional weapons? We will tell you everything about new developments and at the same time teach you how to distinguish “supersonic” from “hypersonic” by ear.

Are you giving “hypersound” - or not?

What is hypersound? First, let’s define it: it would be correct to say “hypersonic speed.” The problem is that the word “hypersound” also refers to elastic waves, similar to simply sound and ultrasonic waves. But we mean aerodynamics and, in order not to get confused in terms, we will say “hypersonic speed”.

In aerodynamics, “hypersonic speed” significantly exceeds the speed of sound - similar to supersonic speed, only even faster.

Somewhere in the seventies of the last century, the following gradation has been established: up to one Mach - subsonic speed, from one to five Machs - supersonic, more than five Machs - hypersonic.

Mach number(M) in our context is most easily defined as the ratio of the speed of a body to the speed of sound in environment. When the speed of the aircraft reaches M=1, this means that its speed is equal to the speed of sound.

The Germans were the first to reach hypersonic speeds using the V-2 rocket in the forties of the last century. Their “weapon of retaliation” reached a speed of 5,760 kilometers per hour, which is more than five Mach numbers (M5) at altitudes above 10,000 meters.

“So what’s the salt then?” - the attentive reader will ask. Since hypersound was achieved in the forties, and all ballistic missiles achieve it, where is the interest and innovation? The problem is that the missiles may develop hypersonic speed, but at that moment they fly along ballistic trajectory, do not actively maneuver and generally try not to move once again... this is fraught with disaster.

But the creation of a cruise missile or aircraft capable of moving at hypersonic speeds and maneuvering has become a very serious task, which designers and engineers are still struggling to solve.

Hypersonic aircraft

Let's start with controllability and the creation of a manned aircraft capable of moving at hypersonic speed, braking and landing.

The Americans were the first to achieve this by creating the X-15 rocket plane in 1959. The very word rocket plane clearly hints that we are talking about a rocket with wings. That’s right, the X-15 is a deep reworking of the ideas and drawings of German rocket scientists of the 1940s. Many parameters are very similar to the V-2 rocket. But the Americans had a pilot inside, and not a banal warhead.

X-15 under the wing of a B-52

The X-15 launched from under the wing of a B-52 strategic bomber at an altitude of about 15 kilometers, then the rocket engine was started, raising the rocket plane to the practical ceiling, followed by a ballistic descent, braking and landing at the airfield. In total, a little less than two hundred flights took place.

So hypersonic speeds conquered humanity almost sixty years ago.

Hypersonic engine

When people currently talk about modern hypersonic vehicles, they mean aircraft equipped with a hypersonic ramjet engine.

Everything is simple here. There is a classic liquid rocket engine, in which the fuel and oxidizer are “carried along” in two different tanks. The aircraft can reach hypersonic speed, but, alas, it is expensive, complex and VERY uneconomical. Modern airplanes use turbojet engines. They use atmospheric air as an oxidizer during the combustion process, making them much lighter and more economical (compared to a rocket engine, of course). Unfortunately, these engines lose efficiency at speeds above M3.

J58 turbojet engine in afterburner, Mach rings visible

To achieve maximum supersonic speeds, a ramjet engine is used. It does not have a turbine and is ineffective at low speeds flight, but can reach high maximum speeds. But even with its help, reaching hypersonic speed is unrealistic. The famous Lockheed SR-71 had just such a design: a turbojet engine capable of operating at high speeds as a ramjet, but it also reached a maximum speed of only about Mach 3.4.

To perform long-distance and economical atmospheric flights at hypersonic speed, a hypersonic ramjet engine was created. It also uses atmospheric air as an oxidizing agent. In this case, the air entering the air intake is decelerated to supersonic speed, participates in the process of fuel combustion and exits through the nozzle, creating jet thrust.

The hypersound problem

Everything is fine, except for one thing: such an engine operates at speeds above six to eight Mach numbers. At a lower speed, it simply will not start, or the engine will detonate. You can recognize it by its air intake, which looks more like a fashionable hand-held vacuum cleaner.

Currently, the main problem for designers is bridging the “gap” between maximum speed ramjet engine and minimum speed hypersonic operation.

There are various developments, including the installation of a third “intermediate” engine, which can provide the necessary acceleration during the “break.” However, so far the general public is only informed about tests of such engines.

In the 1950s–60s, there were projects of nuclear ramjet engines that also promised to achieve speeds in the M 3 - M 4 region. The most famous is the Pluto engine project for the supersonic unlimited-range cruise missile SLAM.

Anti-ship missile "Zircon"

Until now, the most famous Russian hypersonic development was the Zircon anti-ship missile. There is no exact data, but most likely it has a hybrid power plant- a rocket engine that propels the rocket at the speed of a hypersonic engine, - and a scramjet engine (hypersonic ramjet engine), which operates most of the time the rocket flies. This version is supported by its mine location. Intended to be used

Typically, despite reports of successful tests, the Russian missile was never shown to the general public. Most often, to illustrate it, they used a picture depicting the American development of the Boeing X-51 (yes, that same car vacuum cleaner).

Summarizing

It makes no sense to call the Kinzhal anti-ship missile, created on the basis of the Iskander missile, hypersonic. Yes, during flight it reaches speeds of more than Mach five, but at the same time it flies along an aeroballistic trajectory. It also makes no sense to talk about hypersonic speed when describing the Sarmat strategic missile system. Like most ballistic missiles, it reaches hypersonic speeds - and that's normal.

But the combat equipment - the Avangard gliding combat unit - is exactly what we can talk about as an example of modern hypersonic technologies. After separation from the ballistic missile, it can move through the dense layers of the atmosphere at hypersonic speeds in excess of Mach 20, while performing deep maneuvering.

Such are the times now: to be considered a modern hypersonic weapon, you must either actively maneuver after reaching hypersonic speed, or carry a hypersonic ramjet engine. Otherwise, I’m sorry... you’re not in trend, move over and make way for the young and promising.

Which is defined as follows: , where u is the speed of movement of the flow or body, and is the speed of sound in the medium. The sound speed is defined as , where is the adiabatic index of the medium (for an ideal n-atomic gas, the molecule of which has degrees of freedom, it is equal to ). Here is the total number of degrees of freedom of the molecule. At the same time, the number of translational degrees of freedom . For a linear molecule, the number of rotational degrees of freedom, the number of vibrational degrees of freedom (if any). For all other molecules, .

When moving in a medium at supersonic speed, a body necessarily creates a sound wave behind it. With uniform rectilinear motion, the front of the sound wave has a cone-shaped shape, with the apex in the moving body. The emission of a sound wave causes additional energy loss by a moving body (in addition to energy loss due to friction and other forces).

Similar effects of the emission of waves by moving bodies are characteristic of all physical phenomena of wave nature, for example: Cherenkov radiation, a wave created by ships on the surface of the water.

Classification of speeds in the atmosphere

Under normal atmospheric conditions, the speed of sound is approximately 331/sec. More high speeds are sometimes expressed in Mach numbers and correspond to supersonic speeds, with hypersonic speed being part of this range. NASA defines "fast" hypersound in the speed range 10-25 M, where the upper limit corresponds to the first escape velocity. Speeds above are not considered hypersonic speed, but “ return speed» spacecraft to Earth.

Mode comparison

Supersonic Objects

Spaceships and their carriers, as well as most modern fighter aircraft, accelerate to supersonic speeds. Several passenger supersonic aircraft were also developed - Tu-144, Concorde, Aerion. The bullet velocity of most modern firearms is greater than M1.

see also

Notes

Wikimedia Foundation.

• 2010.
• Electrical voltage

Mach number

See what “Supersonic speed” is in other dictionaries: SUPERSONIC SPEED - the speed of movement of a medium or a body in a medium that exceeds the speed of sound in a given medium. Physical encyclopedic Dictionary . M.:. Soviet encyclopedia Chief Editor A. M. Prokhorov. 1983 ...

See what “Supersonic speed” is in other dictionaries:- SUPERSONIC SPEED, speed exceeding the local speed of sound. In dry air at a temperature of 0 ° C, this speed is 330 m/s or 1188 km/h. Its magnitude is usually expressed by the MAX number, which is the ratio of speed... ... Scientific and technical encyclopedic dictionary

Supersonic speed- 1) gas speed V exceeding the local speed of sound a: V > a (M > 1, M Mach number). 2) S. s. flight, the speed of an aircraft exceeding the speed of sound in an undisturbed flow (flight with S.S. is often understood to mean flight at a speed ... ... Encyclopedia of technology

Supersonic speed- the speed of movement of the body (gas flow) exceeds the speed of sound under identical conditions. Characterized by Mach number (M) values; has M values ​​from 1 to 5. Speed ​​exceeding the speed of sound by more than 5 times... ... Marine Dictionary

See what “Supersonic speed” is in other dictionaries:- the speed of movement of a body (gas flow) exceeds the speed of sound under identical conditions (the speed of sound in air at 0°C is 331 m/s). Characterized by the Mach number M (), having values ​​from 1 to 5. Speed ​​exceeding M... ... Big Polytechnic Encyclopedia

supersonic speed- Gas speed exceeding the local speed of sound, . [GOST 23281 78] Topics aerodynamics of aircraft General terms characteristics of gas flow EN supersonic velocity ... Technical Translator's Guide

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