One of the most important tasks of all specialists in the aviation and transport industry is the creation of supersonic passenger aircraft. The analysis of already existing supersonic passenger aircraft made it possible to develop fundamentally new, cost-effective and meeting environmental standards. Consider a number of inventions aimed at creating universal supersonic passenger aircraft that could be used at flight altitudes outside modern air corridors at supersonic speeds.
The supersonic aircraft, designed by Korabef Johann and Prampolini Marko, has improved performance of the Concorde and Tupolev TU-144 aircraft. In particular, the reduction in the noise level that accompanies the overcoming of the sound barrier.
The present invention comprises a fuselage (Figure 1) which is formed by a forward section or nose CN, a middle section or passenger cabin P and a rear section. The fuselage of the aircraft has a constant section, which, starting from the passenger cabin section, gradually expands, and narrows in the rear direction of the aircraft.
Figure 1. Longitudinal sectional view of a super high-speed aircraft
Inside the rear section of the fuselage there are one or more tanks with liquid oxygen R01 and a tank with hydrogen in liquid or sludge form Rv, designed to power the rocket engine.
The aircraft has a triangular gothic wing, as shown in (fig. 2), whose root originates at the level where the extension of the forward fuselage begins. The delta wing is equipped with two flaps on each side of the fuselage.
Figure 2. Perspective view of a super high-speed aircraft
With the help of a cylindrical part, a small wing a1,a2 is fixed at each outer end of the trailing edge of the delta wing. In (Fig. 3) this invention is illustrated.
Figure 3. Small wing in perspective
The movable small wing consists of two trapezoid-shaped elements, which are located on both sides of the cylindrical part. The cylindrical part, the axis of which is parallel to the axis of the fuselage, can be rotated around its axis to install a small wing, depending on the speed of the aircraft. The position of the small wings is horizontal at speeds below 1 Max and vertical at speeds above 1 Max. Changing the positions of the small wing is necessary to solve the problem of combining the center of gravity and the center of thrust application at any aircraft speed.
The aircraft is equipped with an engine system (Figure 1). This system contains two turbojet engines TB1(TB2), two ramjet engines ST1(ST2) and rocket engine Mf.
Two turbojet engines TB1(TB2) are located in the transition area between the passenger cabin P and the rear fuselage section. Turbojet engines are designed for the taxiing phase of the aircraft and the takeoff phase. Shortly before entering the transonic flight region, the turbojet engines are turned off and retracted inside the fuselage. As soon as the landing phase of the aircraft begins and the aircraft speed falls below 1 Max, the turbojet engines are extended and ignited. This solution makes it possible to significantly reduce the size and weight of turbojet engines compared to conventional turbojet engines.
During the takeoff phase, the aircraft is propelled not only by the TB1(TB2) turbojet engines, but also by the rocket engine. The rocket engine can be (Fig. 4) either a single engine with smoothly varying thrust, or a combination of the main engine Mp with several auxiliary engines Ma1,Ma2 with separate thrust.
Figure 4. Rear view of the rocket engine
The rocket engine, located in the rear of the fuselage, has the ability to open and close in the fuselage using the rear hatch P of the aircraft, as shown in (Fig. 5).
Figure 5. Rear view of a super high-speed aircraft
During the takeoff phase, the hatch is fully open, but once the aircraft is at high altitude, the rocket engine is turned off and the hatch is closed, giving the fuselage a streamlined shape. The flight phase at cruising speed begins.
The flight phase at cruising speed occurs with the switching on of the ramjet engines ST1 (ST2) and turning off the rocket engine Mf. Two ramjet engines are placed symmetrically about the longitudinal axis of the aircraft and are designed to create cruising speed. Scramjet engines have a fixed geometry, which reduces their mass and simplifies their design. The thrust of ramjet engines is modulated during flight by changing the flow rate of hydrogen.
The aircraft according to the present invention can carry about twenty passengers. The flight altitude of the aircraft is from 30,000m to 35,000m and can reach speeds from Mach 4 to Mach 4.5.
Of particular interest is a supersonic passenger aircraft, which is proposed to be carried out according to the "duck" aerodynamic configuration. In accordance with the claimed technical solution, the aircraft contains a fuselage, as shown in (Fig. 6), which is connected with the wing 1 with the help of the influx 2. The passenger compartment is located in the central part of the fuselage. In cross section, the nose and central parts of the fuselage are rounded. There is a recess in the tail section of the fuselage.
Figure 6. General view of the aircraft
The aircraft is equipped with engines placed in the engine nacelle 3, which are combined into a "package" with two air intakes 4. This "package" is installed from above behind the deepening of the rear fuselage, which allows to reduce the drag of the vessel, improve balancing in case of failure of one engine.
The deepening of the rear fuselage is aimed at reducing the unevenness of the supersonic flow supplied to the air intakes. This technical solution is limited to the first platform 6 and a pair of second platforms 7, as shown in (Fig. 7).
Figure 7. Top view of the rear fuselage
The first platform 6, made flat, forms an oblique cut of the fuselage. The site can be oriented to the direction of air supply to the air intake of the vessel at an acute angle, the value of which lies in the range from 2 to 10 degrees. With the fuselage skin, the first platform is connected at an angle without a smooth transition, which ensures the presence of a sharp edge 9 at the junction of the platform with the skin, which forms a vortex flow along the sharp edges of the joint. The vortex supersonic flow ensures the removal of the growing boundary layer, formed due to the movement of the flow over the pads, from the peripheral areas of the pads and its flow away from the fuselage.
The second platform 7, made flat, is placed between the air intakes 4 and the first platform 6. They are located at an angle to each other, which is advisable to choose more than 150 degrees. To prevent an increase in aerodynamic drag, the angle between the direction of air supply to the air intake and the connection edge of the second platforms 10 should not exceed 20 degrees.
The presence of the second sites allows you to remove the boundary layer from areas close to the plane of symmetry of the aircraft, due to the formation of an intense vortex. An intense vortex flow is formed in the area of the fin placement between the second platforms. Removing the boundary layer from areas close to the plane of symmetry of the aircraft makes it possible to reduce the thickness of the boundary layer before entering the air intakes.
It should be noted that the removal of the boundary layer immediately before the cut of the air intake is ensured by extending the second platforms beyond this cut. (Fig. 8) illustrates this solution.
Figure 8. View of one of the second flat areas in the place of its extension beyond the air intake section
The difference between the patent of Valeriy Nikolayevich Sirotin and the others is that he proposes a passenger supersonic aircraft with reverse swept wings, which has emergency rescue modules (shown in Fig. 9).
The aircraft, according to the patent, contains a fuselage 1, in the bow of which the cockpit 11 is located. In the middle part, emergency rescue modules 2 are located, which form the outer contour of the fuselage, due to heat-insulated walls. The supersonic aircraft also includes left and right wings 3, which are rotatable relative to the fuselage axis. The power plant of the invention includes four turbojet engines 9.
Figure 9. View of the aircraft from above before turning the right and left wings to the fuselage holding grips
It is worth noting that the aircraft has vertical 6 and horizontal 7 stabilizers. The front horizontal tail 8, with the help of special engines, is installed with the possibility of rotation about the axis along the horizontal of the fuselage.
Both the right and left wing 3 are attached with the possibility of rotation about the axis horizontally of the fuselage. In order to fix the positions of the right and left wings at supersonic speed, there are holding grips in the lower part of the fuselage. Special motors are provided for turning the wings. The amount of rotation of the wings is 53 degrees relative to the horizontal axis of the fuselage. This value provides a shift of the zone where the flow stall begins from the ends of the wings to the root.
(Fig. 10) shows how, during takeoff, the engines of mechanisms 15 turn the right and left wings at an angle of 53 degrees in the direction from the fuselage, and the front horizontal tail assembly rotates at an angle of 85 degrees. This forward-swept aerodynamic configuration allows the aircraft to take off.
Figure 10. Top view of the diagram of the wing turning mechanism
Upon reaching a high subsonic speed, the engines of the mechanisms turn the wings inward towards the axis of the fuselage, where they are fixed with holding grips. There is a turn and the front horizontal tail. Due to these actions, the aircraft changes its aerodynamic configuration (Fig. 11), which allows it to develop supersonic speed.
Figure 11. View of the aircraft from above after turning the right and left wings to the holding grips of the fuselage
For the occasion emergency the vessel is provided with rescue modules (Fig. 12). Each module is equipped with ejection units 21, which are activated at the command of the pilots, a parachute 22, a landing gear 23, and an autonomous power supply system.
Figure 12. Descent of the habitable module
The authors of patent No. 2391254 offer us a supersonic vessel, which is made according to the aerodynamic scheme "tailless with GO". According to the patent, as shown in (Fig. 13), the aircraft contains a fuselage 1, the front part of which includes the cockpit and passenger compartment 8. Particular attention should be paid to the fact that the nose of the fuselage is flattened 7. In the vertical plane, it is made with a radius of 0, 1 ... 5 mm, and in the horizontal 300 ... 1500 mm.
Figure 13. General view of the aircraft
The minimum sonic boom is achieved by the fact that the cross-sectional shape, which is close to a circular shape, has an increase in the radius of the front fuselage.
According to this patent, in order to ensure high efficiency of longitudinal control, create a favorable pitching moment at supersonic speeds, the lower tail part of the fuselage smoothly passes into a flat surface in the transverse direction. The lower tail section of the fuselage ends with the elevator.
To ensure minimal flow disturbances and wave resistance, the authors propose to make a large sweep angle of the order of 78 ... 84 on the root section of the swept wing at the junction of the wing and fuselage 14. And the profile of the leading edge 9 should be made with a radius of curvature of 5 ... 40 mm, to increase the volume of the wing and the value of the maximum allowable angle of attack.
Particular attention should be paid to the engine air intakes 4, which are located on the sides of the fuselage above the upper surface of the wing root, which reduces their adverse effect on the magnitude of the sonic boom. Since the flow slows down in front of the air intakes, the boundary layer is removed through perforated sections 16 (shown in (Fig. 14)), which are made on the planes in front of the air intakes and in them themselves.
Figure 14. Scheme of preloading the wing (fuselage) in front of the air intakes and the scheme of bypassing the boundary layer
The discharge of this boundary layer occurs on the upper surface of the fuselage and wing, through the drain duct 17. But to supply the required amount of air in various modes, supersonic air intakes contain a mechanism for controlled air bypass 18 from the boundary layer drain channel into the air duct channel 19 from the air intakes to the engine.
Implemented on given time supersonic aircraft for one reason or another were withdrawn from use. The inventions presented in this article are aimed at creating supersonic aircraft that have high flight performance and environmental performance.
The main technical tasks for creating such devices are:
Reducing the aerodynamic drag of the vessel;
Reducing the noise level that accompanies breaking the sound barrier;
Reducing emissions of harmful substances into the atmosphere, which is achieved by reduced fuel consumption by improving the performance of air intakes.
Most patented supersonic aircraft have an altitude that is higher than that of a conventional airliner. This advantage allows the use of the aircraft in almost all weather conditions, since the flight is carried out at altitudes where there are no meteorological phenomena that affect normal piloting.
Bibliography:
- Babulin A.A., Vlasov S.A., Subbotin V.V., Titov V.N., Tyurin S.V. Pat. No. 2517629 (RF). IPC B 64 D 33/02, B 64 D 27/20, B 64 C 30/00. Aircraft.
- Bakhtin E.Yu., Zhitenev V.K., Kazhan A.V., Kazhan V.G., Mironov A.K., Polyakov A.V., Remeev N.Kh. Pat. No. 2391254 (RF). IPC B 64 D 33/02, B 64 D 27/16, B 64 C 3/10, B 64 C 1/38, B 64 C30. Supersonic aircraft (options).
- Korabef Johann, Prampolini Marco, Pat. No. 2547962 (RF). IPC B 64 C 30/00, B 64 D 27/020, B 64 C 5/10, B 64 C 5/08. Super high-speed aircraft and the corresponding method of air movement
- Sirotin V.N. Pat. No. 2349506 (RF). IPC B 64 C 3/40, B 64 C30. Passenger supersonic aircraft with reverse swept wings and rescue modules.
Exactly 15 years ago, the last three British Airways Concorde supersonic passenger aircraft made their farewell flight. On that day, October 24, 2003, these aircraft, flying at low altitude over London, landed at Heathrow, and thus ended the short history of supersonic passenger aviation. However, today aircraft designers around the world are once again thinking about the possibility of fast flights - from Paris to New York in 3.5 hours, from Sydney to Los Angeles - in 6 hours, from London to Tokyo - in 5 hours. But before supersonic aircraft return to international passenger routes, developers will have to solve many problems, among which one of the most important is reducing the noise of fast aircraft.
A short history of fast flights
Passenger aviation began to take shape in the 1910s, when the first aircraft specifically designed to transport people through the air appeared. The very first of these was the French Bleriot XXIV Limousine from Bleriot Aeronautique. It was used for pleasure air rides. Two years later, the S-21 Grand appeared in Russia, created on the basis of the Russian Knight heavy bomber Igor Sikorsky. It was built at the Russian-Baltic Carriage Works. Then aviation began to develop by leaps and bounds: first, flights began between cities, then between countries, and then between continents. Airplanes made it possible to get to your destination faster than by train or ship.
In the 1950s, progress in the development of jet engines accelerated significantly, and flights at supersonic speed became available for military aircraft, albeit for a short time. Supersonic speed is usually called movement up to five times faster than the speed of sound, which varies depending on the propagation medium and its temperature. At normal atmospheric pressure at sea level, sound travels at a speed of 331 meters per second, or 1,191 kilometers per hour. As the altitude increases, the density and temperature of the air decreases, and the speed of sound also decreases. For example, at an altitude of 20 thousand meters, it is already about 295 meters per second. But already at an altitude of about 25 thousand meters and as it rises to more than 50 thousand meters, the temperature of the atmosphere begins to gradually increase in comparison with the lower layers, and with it the local speed of sound increases.
The increase in temperature at these altitudes is explained, among other things, by the high concentration of ozone in the air, which forms an ozone shield and absorbs part of the solar energy. As a result, the speed of sound at an altitude of 30,000 meters above the sea is about 318 meters per second, and at an altitude of 50,000 - almost 330 meters per second. In aviation, the Mach number is widely used to measure airspeed. In simple terms, it expresses the local speed of sound for a particular altitude, air density and temperature. Thus, a conventional flight speed equal to two Mach numbers at sea level will be 2383 kilometers per hour, and at an altitude of 10 thousand meters - 2157 kilometers per hour. For the first time, the sound barrier at a speed of 1.04 Mach (1066 kilometers per hour) at an altitude of 12.2 thousand meters was overcome by the American pilot Chuck Yeager in 1947. This was an important step towards the development of supersonic flights.
In the 1950s, aircraft designers in several countries around the world began working on designs for supersonic passenger aircraft. As a result, in the 1970s, the French Concorde and the Soviet Tu-144 appeared. These were the first and so far the only passenger supersonic aircraft in the world. Both types of aircraft used conventional turbojet engines optimized for long-term supersonic flight. Tu-144s were operated until 1977. The planes flew at a speed of 2.3 thousand kilometers per hour and could carry up to 140 passengers. However, tickets for their flights cost an average of 2.5-3 times more than usual. Low demand for fast but expensive flights, as well as the general difficulties in operating and maintaining the Tu-144, led to the fact that they were simply removed from passenger flights. However, the aircraft were used for some time in test flights, including under contract with NASA.
Concorde served noticeably longer - until 2003. Flights on French liners were also expensive and not very popular, but France and Great Britain continued to operate them. The cost of one ticket for such a flight was, in terms of today's prices, about 20 thousand dollars. The French Concorde flew at a speed of just over two thousand kilometers per hour. The plane could cover the distance from Paris to New York in 3.5 hours. Depending on the configuration, Concorde could carry from 92 to 120 people.
The history of the Concorde ended unexpectedly and quickly. In 2000, the Concorde plane crash occurred in which 113 people died. A year later, a crisis began in passenger air transportation caused by the terrorist attacks of September 11, 2001 (two planes with passengers hijacked by terrorists crashed into the towers of the World shopping center in New York, another, a third hit the Pentagon in Arlington County, and a fourth fell in a field near Shanksville, Pennsylvania). Then the warranty period for Concorde aircraft, which was carried out by Airbus. All these factors together made the operation of supersonic passenger aircraft extremely unprofitable, and in the summer and autumn of 2003 airlines Air France and British Airways took turns decommissioning all the Concordes.
After the closure of the Concorde program in 2003, there was still hope for the return of supersonic passenger aviation to service. Designers hoped for new fuel-efficient engines, aerodynamic calculations, and computer-aided design systems that could make supersonic flight economically affordable. But in 2006 and 2008 the International Organization civil aviation adopted new aircraft noise standards that prohibited, among other things, any supersonic flights over populated areas of land during peacetime. This ban does not apply to air corridors specially allocated for military aviation. Work on the projects of new supersonic aircraft slowed down, but today they have begun to gain momentum again.
Quiet supersonic
Today, several enterprises and government organizations in the world are developing supersonic passenger aircraft. Such projects, in particular, are being carried out by the Russian companies Sukhoi and Tupolev, the Central Aerohydrodynamic Institute named after Zhukovsky, the French Dassault, the Japan Aerospace Research Agency, the European concern Airbus, the American Lockheed Martin and Boeing, as well as several startups, including Aerion and Boom technologies. In general, the designers are conditionally divided into two camps. Representatives of the first of them believe that it will not be possible to develop a “quiet” supersonic aircraft corresponding in terms of noise to subsonic airliners in the near future, which means that it is necessary to build a fast passenger aircraft that will switch to supersonic where it is allowed. Such an approach, the designers from the first camp believe, will still reduce the time of flight from one point to another.
The designers from the second camp mainly focused on the fight against shock waves. In flight at supersonic speed, the airframe of an aircraft generates many shock waves, the most significant of which occur in the nose and in the tail area. In addition, shock waves usually appear on the leading and trailing edges of the wing, on the leading edges of the tail, in the areas of swirlers of the flow and on the edges of the air intakes. A shock wave is a region in which the pressure, density, and temperature of the medium experience a sharp and strong jump. Observers on the ground perceive such waves as a loud bang or even an explosion - it is because of this that supersonic flights over the populated part of the land are prohibited.
The effect of an explosion or a very loud pop is produced by the shock waves of the so-called N-type, which are formed during the explosion of a bomb or on the airframe of a supersonic fighter. On the graph of pressure and density growth, such waves resemble the letter N of the Latin alphabet due to a sharp increase in pressure at the wave front with a sharp drop in pressure after it and subsequent normalization. In laboratory experiments, researchers at the Japan Aerospace Exploration Agency found that changing the shape of a glider can smooth out peaks in a shockwave graph, turning it into an S-type wave. Such a wave has a smooth pressure drop, which is not as significant as that of the N-wave. NASA experts believe that S-waves will be perceived by observers as the distant slam of a car door.
N-wave (red) before aerodynamic optimization of a supersonic airframe and similarity of S-wave after optimization
In 2015, Japanese designers assembled the D-SEND 2 unmanned glider, whose aerodynamic shape was designed to reduce the number and intensity of shock waves generated on it. In July 2015, the developers tested the airframe at the Esrange missile range in Sweden and noted a significant reduction in the number of shock waves generated on the surface of the new airframe. During the test, D-SEND 2, not equipped with engines, was dropped from hot air balloon from a height of 30.5 thousand meters. During the fall, the glider, 7.9 meters long, picked up a speed of Mach 1.39 and flew past tethered balloons equipped with microphones located at different heights. At the same time, the researchers measured not only the intensity and number of shock waves, but also analyzed the influence of the state of the atmosphere on their early occurrence.
According to the Japanese agency, the sonic boom from aircraft comparable in size to the Concorde supersonic passenger aircraft and made according to the D-SEND 2 scheme, when flying at supersonic speed, will be half as intense as before. The Japanese D-SEND 2 differs from the gliders of conventional modern aircraft in the non-axisymmetric arrangement of the bow. The keel of the device is shifted to the bow, and the horizontal tail unit is made all-moving and has a negative installation angle with respect to the longitudinal axis of the airframe, that is, the empennage tips are below the attachment point, and not above, as usual. The airframe wing has a normal sweep, but is made stepped: it smoothly mates with the fuselage, and part of its leading edge is located at an acute angle to the fuselage, but closer to the trailing edge this angle increases sharply.
According to a similar scheme, the supersonic American startup Aerion is currently being created and is being developed by Lockheed Martin by order of NASA. With an emphasis on reducing the number and intensity of shock waves, the Russian (Supersonic Business Aircraft / Supersonic Passenger Aircraft) is also being designed. Some of the fast passenger aircraft projects are scheduled to be completed in the first half of the 2020s, but aviation regulations will still not be revised by then. This means that the new aircraft will initially perform supersonic flights only over water. The fact is that in order to remove the restriction on supersonic flights over the populated part of the land, developers will have to conduct many tests and submit their results to the aviation authorities, including the US Federal Aviation Administration and the European Aviation Safety Agency.
S-512/Spike Aerospace
New engines
Another serious obstacle to the creation of a mass-produced passenger supersonic aircraft is the engines. Designers today have found many ways to make turbojet engines more economical than they were ten or twenty years ago. This includes the use of gearboxes that remove the rigid coupling of the fan and turbine in the engine, and the use of ceramic composite materials to optimize the temperature balance in the hot zone of the power plant, and even the introduction of an additional - third - air circuit in addition to the already existing two, internal and external. In the field of creating economical subsonic engines, designers have already achieved amazing results, and ongoing new developments promise significant savings. You can read more about advanced research in our material.
But, despite all these developments, it is still difficult to call supersonic flight economical. For example, the promising supersonic passenger aircraft of the Boom Technologies startup will receive three turbofan engines of the JT8D family from Pratt & Whitney or J79 from GE Aviation. In cruise flight, the specific fuel consumption of these engines is about 740 grams per kilogram-force per hour. At the same time, the J79 engine can be equipped with an afterburner, which increases fuel consumption by up to two kilograms per kilogram-force per hour. Such an expense is comparable to the fuel consumption of engines, for example, of the Su-27 fighter, whose tasks differ significantly from the transportation of passengers.
For comparison, the specific fuel consumption of the world's only serial D-27 turbopropfan engines installed on the Ukrainian An-70 transporter is only 140 grams per kilogram-force per hour. The American CFM56 engine, the “classic” of Boeing and Airbus liners, has a specific fuel consumption of 545 grams per kilogram-force per hour. This means that without a major redesign of jet aircraft engines, supersonic flights will not become cheap enough to be widely adopted, and will be in demand only in business aviation - high fuel consumption leads to higher ticket prices. It will not be possible to reduce the high cost of supersonic air transportation by volumes either - the aircraft being designed today are designed to carry from 8 to 45 passengers. Ordinary planes can accommodate more than a hundred people.
However, in early October of this year, GE Aviation projected a new Affinity turbofan jet engine. These power plants are planned to be mounted on a promising supersonic passenger aircraft AS2 from Aerion. New power point structurally combines the features of jet engines with a low bypass ratio for combat aircraft and power plants with a high bypass ratio for passenger aircraft. At the same time, there are no new and breakthrough technologies in Affinity. The new GE Aviation engine is classified as a medium bypass powerplant.
The basis of the engine is a modified CFM56 turbofan gas generator, which, in turn, is structurally based on the gas generator from the F101, the power plant for the B-1B Lancer supersonic bombers. The power plant will receive a modernized electronic-digital engine management system with full responsibility. The developers did not disclose any details about the design of the promising engine. However, GE Aviation expects the specific fuel consumption of the Affinity engines to be not much higher than, or even comparable to, the fuel consumption of modern turbofan engines in conventional subsonic passenger aircraft. How this can be achieved for supersonic flight is not clear.
Boom / Boom Technologies
Projects
Despite the many projects of supersonic passenger aircraft in the world (including even the unrealistic project of converting the Tu-160 strategic bomber into a passenger supersonic liner, proposed by Russian President Vladimir Putin), the AS2 of the American startup Aerion, S-512, can be considered the closest to flight testing and small-scale production. Spanish Spike Aerospace and American Boom Technologies Boom. It is planned that the first will fly at Mach 1.5, the second at Mach 1.6, and the third at Mach 2.2. The X-59 aircraft, created by Lockheed Martin by order of NASA, will be a technology demonstrator and a flying laboratory; it is not planned to launch it into a series.
Boom Technologies has already said it will try to make supersonic flights very cheap. For example, the cost of a flight from New York to London was estimated at Boom Technologies at five thousand dollars. This is how much a flight on this route costs today in the business class of an ordinary subsonic airliner. The Boom liner will fly at subsonic speeds over populated land and go supersonic over the ocean. The aircraft, with a length of 52 meters and a wingspan of 18 meters, can carry up to 45 passengers. Until the end of 2018, Boom Technologies plans to select one of several new aircraft projects for implementation in metal. The first flight of the aircraft is scheduled for 2025. The company has postponed these deadlines; Boom was originally scheduled to take to the air in 2023.
According to preliminary calculations, the length of the AS2 aircraft, designed for 8-12 passengers, will be 51.8 meters, and the wingspan will be 18.6 meters. The maximum takeoff weight of the supersonic aircraft will be 54.8 tons. The AS2 will fly over water at a cruising speed of Mach 1.4-1.6, decelerating to Mach 1.2 over land. A slightly lower flight speed over land, coupled with a special aerodynamic shape of the airframe, will, as the developers expect, almost completely avoid the formation of shock waves. The flight range of the aircraft at a speed of Mach 1.4 will be 7.8 thousand kilometers and 10 thousand kilometers at a speed of Mach 0.95. The first flight of the aircraft is planned for the summer of 2023, and for October of the same year - the first transatlantic flight. Its developers will coincide with the 20th anniversary of the last flight of the Concorde.
Finally, Spike Aerospace plans to begin flight testing of the full S-512 prototype no later than 2021. Deliveries of the first production aircraft to customers are scheduled for 2023. According to the project, the S-512 will be able to carry up to 22 passengers at speeds up to Mach 1.6. The flight range of this aircraft will be 11.5 thousand kilometers. Since last October, Spike Aerospace has several smaller models of supersonic aircraft. Their purpose is to test design solutions and the effectiveness of flight controls. All three promising passenger aircraft are being created with an emphasis on a special aerodynamic shape that will reduce the intensity of shock waves generated during supersonic flight.
In 2017, the volume of aviation passenger traffic worldwide amounted to four billion people, of which 650 million made long flights ranging from 3.7 to 13 thousand kilometers. 72 million "long-haul" passengers flew first and business class. It is these 72 million people that the developers of supersonic passenger aircraft are targeting first, believing that they will gladly pay a little more money for the opportunity to spend about half the time in the air than usual. However, supersonic passenger aviation is likely to develop rapidly after 2025. The fact is that research flights of the X-59 laboratory will begin only in 2021 and will last for several years.
The results of the research obtained during the X-59 flights, including those over volunteer settlements (their inhabitants agreed to have supersonic aircraft fly over them on weekdays; after the flights, observers will tell the researchers about their perception of noise), it is planned to transfer to US Federal Aviation Administration review. As expected, on their basis, it may revise the ban on supersonic flights over the populated part of the land, but this will not happen until 2025.
Vasily Sychev
When can a new supersonic passenger plane take to the skies? Business jet based on the Tu-160 bomber: real? How to silently break the sound barrier?
Tu-160 is the largest and most powerful supersonic and variable wing aircraft in the history of military aviation. Among the pilots he received the nickname "White Swan". Photo: AP
Do supersonic passenger cars have a future? - I asked not so long ago the outstanding Russian aircraft designer Genrikh Novozhilov.
Of course have. At least a supersonic business aircraft will certainly appear, - answered Genrikh Vasilyevich. - I had a chance to talk with American businessmen more than once. They clearly stated: "If such an aircraft appeared, Mr. Novozhilov, then, no matter how expensive it was, they would instantly buy it from you." Speed, altitude and range are three factors that are always relevant.
Yes, they are relevant. The dream of any businessman is to fly across the ocean in the morning, make a big deal, and return home in the evening. Modern aircraft fly no faster than 900 km/h. A supersonic business jet will have a cruising speed of about 1900 km per hour. What prospects for the business world!
That is why neither Russia, nor America, nor Europe has ever abandoned attempts to create a new supersonic passenger car. But the history of those that have already flown - the Soviet Tu-144 and the Anglo-French Concorde - has taught us a lot.
In December of this year, it will be half a century since the Tu-144 made its first flight. And a year later, the liner showed what exactly it is capable of: it broke the sound barrier. He picked up a speed of 2.5 thousand km / h at an altitude of 11 km. This event has gone down in history. There are still no analogues of passenger boards in the world that are able to repeat such a maneuver.
"One hundred and forty-four" opened a fundamentally new page in the global aircraft industry. They say that at one of the meetings in the Central Committee of the CPSU, designer Andrei Tupolev reported to Khrushchev: the car is turning out to be quite voracious. But he just waved his hand: your job is to wipe the nose of the capitalists, and we have kerosene - at least fill up ...
Nose - lost. Kerosene - flooded.
However, the European competitor, which took off later, also did not excel in efficiency. So, in 1978, nine "Concordes" brought their companies about $ 60 million in losses. And only government subsidies saved the situation. Nevertheless, the Anglo-French flew until November 2003. But the Tu-144 was written off much earlier. Why?
First of all, Khrushchev's optimism was not justified: an energy crisis erupted in the world and kerosene prices rushed up. The supersonic first-born was immediately dubbed "a boa constrictor around Aeroflot's neck." Huge fuel consumption also knocked out the design flight range: the Tu-144 did not reach either Khabarovsk or Petropavlovsk-Kamchatsky. Only from Moscow to Alma-Ata.
And if only this. A 200-ton "iron", cruising over densely populated areas at supersonic speed, literally blew up the entire space along the route. Complaints poured in: cows' milk yields fell, chickens stopped laying, acid rains crushed ... Where is the truth, where is the lie - today you can’t say for sure. But the fact remains: the Concorde flew only over the ocean.
Finally, and most importantly, disasters. One - in June 1973 at the Paris air show in Le Bourget, as they say, in full view of the whole planet: the crew of test pilot Kozlov wanted to demonstrate the capabilities of the Soviet airliner ... The other - in five years. Then a test flight was carried out with the engines of the new series: they just had to pull the plane to the required range.
"Concorde" also did not escape the tragedy: the plane crashed in July 2000 while taking off from Charles de Gaulle Airport. Ironically, it crashed almost where the Tu-144 had once been. 109 people on board and four on the ground were killed. Regular passenger traffic resumed only a year later. But another series of incidents followed, and a bullet was also put on this supersonic aircraft.
On December 31, 1968, the first flight of the Tu-144 took place, two months earlier than the Concorde. And on June 5, 1969, at an altitude of 11,000 meters, our aircraft was the first in the world to break beyond the sound barrier. Photo: Sergey Mikheev / RG
Today, at a new stage in the development of technology, scientists need to find a balance between conflicting factors: the good aerodynamics of the new supersonic aircraft, low fuel consumption, as well as severe restrictions on noise and sonic boom.
How realistic is it to create a new passenger supersonic aircraft based on the Tu-160 bomber? From a purely engineering point of view, it is quite, experts say. And there are examples in history when military aircraft successfully "removed their shoulder straps" and flew "to civilian life": for example, the Tu-104 was created on the basis of the Tu-16 long-range bomber, and the Tu-114 was based on the Tu-95 bomber. In both cases, the fuselage had to be redone - to change the wing layout, to expand the diameter. In fact, these were new aircraft, and quite successful. By the way, a curious detail: when the Tu-114 first flew to New York, there was neither a suitable ladder nor a tractor at the dumbfounded airport ...
Similar work will at least be required for the conversion of the Tu-160. However, how cost-effective will this solution be? Everything needs to be carefully evaluated.
How many of these planes do you need? Who will fly them and where? To what extent will they be commercially available to passengers? How soon will the development costs pay off? .. Tickets for the same Tu-144 cost 1.5 times more than usual, but even such a high cost did not cover operating costs.
Meanwhile, according to experts, the first Russian supersonic administrative aircraft (business jet) can be designed in seven to eight years if there is a backlog on the engine. Such an aircraft can accommodate up to 50 people. The overall demand in the domestic market is projected at the level of 20-30 cars at a price of 100-120 million dollars.
Serial supersonic passenger aircraft of the new generation may appear around 2030
Designers on both sides of the ocean are working on projects for supersonic business jets. Everyone is looking for new layout solutions. Someone offers an atypical tail, someone - a completely unusual wing, someone - a fuselage with a curved central axis ...
TsAGI specialists are developing a SDS / SPS project (“supersonic business aircraft / supersonic passenger aircraft”): according to the idea, it will be able to perform transatlantic flights over a distance of up to 8600 km at a cruising speed of at least 1900 km / h. Moreover, the salon will be made transformable - from an 80-seat to a 20-seat VIP class.
And last summer at the air show in Zhukovsky, one of the most interesting was the model of a high-speed civil aircraft created by TsAGI scientists as part of the international project HEXAFLY-INT. This aircraft must fly at a speed of more than 7-8 thousand km / h, corresponding to Mach 7 or 8.
But in order for a high-speed civil aircraft to become a reality, a huge range of tasks must be solved. They are related to materials, the hydrogen power plant, its integration with the airframe and obtaining high aerodynamic efficiency of the aircraft itself.
And what is already absolutely certain: the design features of the designed winged machine will be clearly non-standard.
Competently
Sergey Chernyshev, Director General of TsAGI, Academician of the Russian Academy of Sciences:
Sonic boom level ( sharp drop pressure in the shock wave) from the Tu-144 was 100-130 pascals. But modern research has shown that it can be brought up to 15-20. Moreover, reduce the volume of the sonic boom to 65 decibels, which is equivalent to noise big city. Until now, there are no official standards for the permissible level of sonic boom in the world. And most likely it will be determined no earlier than 2022.
We have already proposed the appearance of a demonstrator of a supersonic civil aircraft of the future. The sample should show the feasibility of reducing sonic boom in supersonic cruising and airport noise. Several options are being considered: a plane for 12-16 passengers, also for 60-80. There is a variant of a very small business aircraft - for 6-8 passengers. These are different weights. In one case, the machine will weigh about 50 tons, and in the other - 100-120, etc. But we will start from the first of the designated supersonic aircraft.
According to various estimates, there is already an unrealized demand for fast flights on the market. business people on aircraft with a passenger capacity of 12-16 people. And, of course, the car must fly at a distance of at least 7-8 thousand kilometers along transatlantic routes. Cruise speed will be Mach 1.8-2, which is about twice the speed of sound. This speed is a technological barrier to the use of conventional aluminum materials in the airframe design. Therefore, the dream of scientists is to make an aircraft entirely from thermal composites. And there are good practices.
Clear requirements for the aircraft must be determined by the launch customer, and then at the stages of preliminary design and experimental design work, some change in the initial appearance of the aircraft obtained at the preliminary design stage is possible. But the sound principles of sonic boom reduction remain unchanged.
The short-term passenger operation of the supersonic Tu-144 was limited to flights from Moscow to Alma-Ata. Photo: Boris Korzin/ TASS Newsreel
I think we are 10-15 years away from the flying prototype. In the near future, according to our plans, a flying demonstrator should appear, the appearance of which is being worked out. Its main task is to demonstrate the basic technologies for building a supersonic aircraft with a low level of sonic boom. This is a necessary step in the work. A production supersonic aircraft of a new generation may appear on the horizon of 2030.
Oleg Smirnov, Honored Pilot of the USSR, Chairman of the Civil Aviation Commission of the Public Council of Rostransnadzor:
To make a passenger supersonic aircraft based on the Tu-160? For our engineers - absolutely real. No problem. Moreover, this machine is very good, with excellent aerodynamic qualities, a good wing and fuselage. However, today any passenger aircraft must first of all comply with international airworthiness and technical requirements. The discrepancies, if we compare the bomber and the passenger plane, are more than 50 percent. For example, when some say that during the alteration it is necessary to "inflate the fuselage", one must understand that the Tu-160 itself weighs more than 100 tons. "Inflate" is to add more weight. And that means - to increase fuel consumption, reduce speed and height, make the device absolutely unattractive for any airline in terms of its operating costs.
To create a supersonic aircraft for business aviation, we need new avionics, new aircraft engines, new materials, new types of fuel. On the Tu-144, kerosene, as they say, flowed like a river. Today, this is impossible. And most importantly, there should be massive demand for such an aircraft. One or two cars commissioned by millionaires will not solve the financial problem. Airlines will have to lease it and "work off" the cost. On whom? Naturally, on passengers. From an economic point of view, the project will be a failure.
Sergey Melnichenko, Director General of the ICAA "Safety Flights":
In the almost 35 years that have passed since the start of serial production of the Tu-160, technology has advanced, and this will have to be taken into account in the deep modernization of the existing aircraft. Aircraft builders say it's much easier and cheaper to build a new aircraft according to a new concept than to rebuild an old one.
Another question: if the Tu-160 is rebuilt specifically for a business jet, will the Arab sheikhs still be interested in it? However, there are several "buts". The aircraft will need to obtain an international certificate (and the European Union and the United States are behind its issuance), which is very problematic. In addition, new economical engines will be needed, which we do not have. Those that are available do not consume fuel, but drink.
If the plane is converted to transport economy passengers (which is unlikely), then the question is where to fly and who to carry? Last year, we only just approached the figure of 100 million passengers carried. In the USSR, these figures were much higher. The number of airfields has decreased several times. Not everyone who would like to fly to the European part of the country from Kamchatka and Primorye can afford it. Tickets for a "fuel-drinking plane" will be more expensive than for Boeings and Airbuses.
If the plane is planned to be rebuilt purely for the interests of the leaders of large companies, then most likely it will be so. But then this question concerns only them, and not the Russian economy and people. Although in this case it is difficult to imagine that flights will be operated only to Siberia or to Far East. The problem with the noise in the area. And if the updated plane is not allowed to Sardinia, then who needs it?
The idea of Russian President Vladimir Putin, inspired by the flight of the new "White Swan", to create a supersonic aircraft made not only the employees of the Kazan Aircraft Building Plant think, but many other observers as well. Can a missile carrier inspire designers to create new types of supersonic aircraft?
The largest and most powerful supersonic aircraft Tu-160 in the history of military aviation, known to many by the nickname "White Swan", has recently received a new life. For the first time in many years, the Kazan Aircraft Building Plant presented to the public an updated Tu-160M bomber named after the first Commander-in-Chief of the Russian Air Force Pyotr Deinekin.
The Supreme Commander-in-Chief of the RF Armed Forces and Russian President Vladimir Putin personally observed the first flight of the missile carrier. The head of state was deeply impressed by the flight of the new White Swan and highly appreciated the professionalism of the pilots who performed the maneuver, asking them to thank the pilots even before the aircraft landed. There was nothing surprising in the president's emotions, since Putin himself piloted the Tu-160 missile carrier back in 2005.
Upon completion of the flight, the president proposed to Kazan aircraft designers to create a version of the passenger supersonic Lebed for civil aviation based on the new Tu-160M.
But in order to understand how realistic it is to implement the idea of Vladimir Putin, one should turn to the history of Russian aviation and remember what steps aircraft designers have already taken in this direction.
Tu-144
One of the biggest industrial successes in the history of Russia was the creation of the Tu-144 aircraft. It was made long before the Tu-160 and became the first supersonic passenger airliner in the history of mankind. In addition, the Tu-144 is still one of the two types of supersonic passenger aircraft known to history.
The airliner was created on the instructions of the Council of Ministers of the USSR, issued on July 19, 1963. Serious demands were placed on the first supersonic passenger aircraft. The aircraft had to be capable of flying at a cruising speed of 2,300 to 2,700 km/h for a distance of up to 4,500 kilometers, while carrying up to 100 passengers on board.
The Tupolev Design Bureau created the first prototype of the aircraft in 1965. Three years later, the aircraft took to the skies for the first time, two months ahead of its main and only competitor, the famous British-French Concorde.
The Tu-144 had a number of design features that even externally markedly distinguished it from other aircraft. There were no flaps and slats on its wings: the aircraft slowed down due to the deviating nose of the fuselage. In addition, the ancestor of modern GPS navigators was installed on the airliner - the PINO system (Projection indicator of the navigation situation), which projected the necessary coordinates onto the screen from the filmstrip.
However, due to the too high costs of operating and maintaining the airliner, the Soviet Union abandoned the further production of the Tu-144. By the time production was abandoned, only 16 aircraft survived, two of which were later destroyed as a result of the infamous accident at the international air show in Le Bourget in 1973 and in the crash over Yegoryevsk in 1978. At the moment, there are only eight assembled aircraft left in the world, three of which can be fully restored and are ready for further use.
SPS-2 and Tu-244
Photo: Stahlkocher / wikimedia.org
Another project on which serious expectations were placed was the SPS-2, which was later given the promising name Tu-244 by the developer, the Tupolev Design Bureau.
The first information about the work on the second generation supersonic passenger airliner dates back to approximately 1971 - 1973 of the last century.
When developing the Tu-224, the designers took into account both the experience of creating and operating its predecessors - the Tu-144 and Concorde, and the Tu-160, as well as American projects of supersonic aircraft.
As conceived by the developers of the SPS-2, the new airliner was supposed to lose the main "calling card" of its predecessor - the forward fuselage deflected downward. In addition, the cockpit glazing area had to be reduced to a minimum sufficient for review. For takeoff and landing of the aircraft, it was planned to use an optical-electronic review system.
Also, the designed aircraft had to rise to a height of up to 20 kilometers and fit on board about 300 passengers. To achieve such parameters, it was necessary to dramatically increase its size in all respects, which was planned to be done: with a fuselage length of almost 90 meters and a wingspan of about 50 meters, the Tu-244 would look like a giant against the background of any existing analogues.
But the maximum speed of the airliner, in comparison with its predecessors, practically remained the same: the speed limit of the SPS-2 did not exceed 2500 km / h. In contrast, it was planned to increase the maximum flight distance to about 9000 kilometers by reducing fuel consumption.
However, the production of such a supersonic heavyweight in reality modern world turned out to be economically unviable. Due to the increased requirements for environmental standards, the cost of operating such a Tu-244 aircraft at the moment is unbearable both for the aircraft manufacturer itself and for the country's economy as a whole.
Tu-344 and Tu-444
These aircraft were developed by the Tupolev Design Bureau (later Tupolev JSC, now Tupolev PJSC) as a response to the growing global demand for fast and small business class aircraft. So there were various projects of SBS - supersonic business aircraft.
Such aircraft were supposed to be small in size and able to carry about 10 passengers. The first SBS project from Tupolev - Tu-344 - was planned to be manufactured back in the 90s of the last century on the basis of the Tu-22M3 military supersonic bomber. But its development turned out to be a failure in the initial stages, since for international flights the aircraft also had to meet high requirements in the field, which it did not meet already in the early stages of project development. Therefore, the designer refused further work on the creation of the Tu-344.
Work on the project of his successor - the Tu-444 - began in the early 2000s, its development reached the stage of the first sketches. Despite the fact that the problems in the field of ecology were solved, the implementation of the project required the attraction of large financial investments, but Tupolev failed to find investors interested in this.
S-21 (SSBJ)
Photo: Slangcamm / wikimedia.org
The only domestic project to create a supersonic aircraft for civil aviation, which was not developed by the Tupolev Design Bureau, was the project of the C-21 aircraft, also known as the Sukhoi Supersonic Business Jet (SSBJ).
Work on this project of the Sukhoi Design Bureau began in the 80s. The design bureau understood that the demand for large supersonic airliners had fallen since the time of the Concorde and Tu-144 and would only decrease in the future for reasons of economy. Therefore, Sukhoi designers were among the first to come up with the idea of creating a supersonic business aircraft designed for non-stop flights between world capitals.
But the development of the S-21 was prevented by the collapse of the USSR, with which state funding for the project ceased.
After the collapse of the Soviet Union, Sukhoi tried for many years to attract private investors to the project in Russia and abroad. The volume of incoming investments made it possible to conduct the first tests of engines for the S-21 in 1993.
But to complete the creation and start mass production of the aircraft, according to Mikhail Simonov, who was at that time the head of Sukhoi, another one billion US dollars was required, but the company could not find new investors.
"Turn on supersonic!"
Supersonic passenger aircraft - what do we know about them? At least the fact that they were created relatively long ago. But, for various reasons, they were not used for as long, and not as often as they could. Even today, they exist only as design models.
Why is that? What is the peculiarity and "secret" of supersonic? Who created this technology? Also, what will be the future? supersonic aircraft in the world, and of course - in Russia? We will try to answer all these questions.
"Farewell Flight"
So, since the last three functioning supersonic passenger aircraft made their last flights, after which they were decommissioned, fifteen years have passed. It was back in 2003. Then, on October 24, they all together "said goodbye to the sky." The last time they flew at low altitude, over the capital of Great Britain.
We then landed at London Heathrow Airport. These were Concorde aircraft owned by British Airways. And with such a “farewell flight” they completed a very short history of passenger transportation, at a speed exceeding the sound ...
That's what you might have thought a few years ago. But now it is already possible to say with certainty. This is the finale of only the first stage of this story. And probably - all its bright pages are yet to come.
Today is preparation, tomorrow is flight
Today, many companies and aircraft designers are thinking about the prospects for supersonic passenger aviation. Some are making plans to revive it. Others are already preparing for it.
After all, if it could exist and function effectively a few decades ago, today, with technologies that have seriously stepped forward, it is quite possible not only to revive it, but also to solve a number of problems that forced leading airlines to abandon it.
And the prospects are too tempting. The possibility of a flight, for example, from London to Tokyo, in five hours, seems very interesting. Cross the distance from Sydney to Los Angeles in six hours? And get from Paris to New York in three and a half? With passenger aircraft, which is capable of flying at a higher speed than sound travels, this is not at all difficult.
But, of course, before the triumphant "return" of such a air space, - scientists, engineers, designers, and many others - still have a lot of work to do. It is necessary not only to restore what once was by offering new model. Not at all.
The goal is to solve many problems that are associated with passenger supersonic aviation. The creation of aircraft that will not only demonstrate the capabilities and power of the countries that built them. But they will also be really effective. So much so as to occupy their worthy niche in aviation.
History of supersonic. Part 1. What happened in the beginning...
Where did it all begin? In fact, from simple passenger aviation. And such is already more than a century old. Its design began in the 1910s, in Europe. When craftsmen from the most developed countries of the world created the first aircraft, the main purpose of which was to transport passengers over various distances. That is - a flight, with many people on board.
The first among them is the French Bleriot XXIV Limousine. It belonged to the aircraft manufacturer Bleriot Aeronautique. However, it was used mainly for the amusement of those who paid for pleasure "walks" - flights on it. Two years after its creation, an analogue appears in Russia.
It was the S-21 Grand. It was designed on the basis of the "Russian Knight" created by Igor Sikorsky - a heavy bomber. And the construction of this passenger aircraft was carried out by the workers of the Baltic Carriage Works.
Well, after that, progress was unstoppable. Aviation developed rapidly. And passenger, in particular. At first there were flights between specific cities. Then the planes were able to overcome the distances between states. Finally, aircraft began to cross the oceans and fly from one continent to another.
Developing technology and an increasing number of innovations allowed aviation to travel very quickly. Much faster than trains or ships. And for her, after all, there were practically no barriers. There was no need to change from one transport to another, not only, say, traveling to some particularly distant "end of the world."
Even when it is necessary to cross land and water expanses at once. Nothing stopped the planes. And this is natural, because they fly over everything - continents, oceans, countries ...
But time flew by quickly, the world changed. Of course, the aviation industry also developed. Aircraft over the next few decades, until the 1950s, changed so much, compared with those that flew back in the early 1920s and 30s, that they became something completely different, special.
And so, in the middle of the twentieth century, the development of the jet engine went very fast, even in comparison with the previous twenty or thirty years, at a pace.
A small information digression. Or - a little physics
Advanced developments have allowed aircraft to “accelerate” to a speed greater than that with which sound propagates. Of course, first of all, it was applied in military aviation. After all, we are talking about the twentieth century. Which, sadly to realize it, was a century of conflicts, two world wars, the "cold" struggle of the USSR and the USA ...
And almost every new technology created by the leading states of the world was first of all considered from the point of view of how it can be used in defense or attack.
So planes could now fly at speeds never seen before. Faster than sound. And what is its specificity?
First of all, it is obvious that this is a speed that exceeds that with which sound is carried. But, remembering the basic laws of physics, we can say that in different conditions, it may differ. Yes, and “exceeds” is a very loose concept.
And therefore - there is a special standard. Supersonic speed is the one that exceeds the sound speed up to five times, taking into account the fact that depending on temperature and other environmental factors, it can change.
For example, if we take the normal Atmosphere pressure, at sea level, then in this case, the speed of sound will be equal to an impressive figure - 1191 km / h. That is, 331 meters are overcome in a second.
But, which is especially important when designing supersonic aircraft, as you climb, the temperature decreases. This means that the speed with which sound propagates is very significant.
So let's say, if you rise to a height of 20 thousand meters, then here it will be already 295 meters per second. But there is another important point.
At 25,000 meters above sea level, the temperature begins to rise as it is no longer the lower atmosphere. And so it goes on. Or rather, higher. Let's say at an altitude of 50,000 meters it will be even hotter. Consequently, the speed of sound there - increases even more.
Interesting - how much? Rising 30 kilometers above sea level, you find yourself in the "zone" where sound travels at a speed of 318 meters per second. And at 50,000 meters, respectively - 330 m / s.
On the Mach number
By the way, it is interesting that in order to simplify the understanding of the features of the flight and work in such conditions, the Mach number is used in aviation. A general description of this can be reduced to the following conclusions. It expresses the speed of sound that takes place under given conditions, at a particular height, at a given temperature and air density.
For example, the flight speed, which is equal to two Mach numbers, at an altitude of ten kilometers above the ground, under normal conditions, will be 2,157 km/h. And at sea level - 2,383 km / h.
History of supersonic. Part 2. Overcoming barriers
By the way, for the first time he reached the speed of flight, more than 1 Mach, a pilot from the USA - Chuck Yeager. This happened in 1947. Then he "dispersed" his plane, flying at an altitude of 12.2 thousand meters above the ground, to a speed of 1066 km / h. Thus was the first supersonic flight on earth.
Already in the 1950s, work began on the design and preparation for serial production of passenger aircraft capable of flying at a speed - faster than sound. They are led by scientists and aircraft designers from the most powerful countries in the world. And they manage to succeed.
The same "Concorde", a model - which will be finally abandoned in 2003, was created in 1969. This is a joint - British-French development. The symbolically chosen name - "Concorde", from French, is translated as "consent".
It was one of two existing types of supersonic passenger aircraft. Well, the creation of the second (or rather - chronologically - the first) is the merit of the aircraft designers of the USSR. The Soviet analogue of the Concorde is called the Tu-144. It was designed in the 1960s and first flew on December 31, 1968. One year before the British-French model.
Other types of supersonic passenger aircraft, up to this day, have not been implemented. Both the Concorde and the Tu-144 flew thanks to turbojet engines, which were specially rebuilt in order to operate at supersonic speed for a long time.
The Soviet analogue of the Concorde was operated for a much shorter period. Already in 1977 it was abandoned. The plane flew on average at a speed of 2,300 kilometers per hour and could carry up to 140 passengers at a time. But at the same time, the price of a ticket for such a “supersonic” flight was two, two and a half, or even three times more than for an ordinary one.
Of course, these were not in great demand among Soviet citizens. And servicing the Tu-144 was not easy and expensive. Therefore, in the USSR they were so quickly abandoned.
Concordes lasted longer, although tickets for the flights they flew were also expensive. And the demand was also not great. But still, despite this, they continued to be exploited, both in the UK and in France.
If you recalculate the cost of a ticket for Concorde, in the 1970s, at today's rate, then it will be about two tens of thousands of dollars. For a one way ticket. You can understand why the demand for them was somewhat less than for flights using aircraft that do not reach supersonic speeds.
The Concorde could take on board from 92 to 120 passengers at a time. He flew at a speed of more than 2 thousand km / h and covered the distance from Paris to New York in three and a half hours.
So several decades passed. Until 2003.
One of the reasons for the refusal to operate this model was a plane crash that occurred in 2000. Then, there were 113 people on board the crashed Concorde. They all died.
Later, an international crisis began in the field of passenger air transportation. Its cause is the terrorist attacks that took place on September 11, 2001, on the territory of the United States.
Moreover, to everything, the warranty period for Concorde is expiring by Airbus. All this together made the further operation of supersonic passenger aircraft extremely unprofitable. And in 2003, all Concordes were written off in turn, both in France and in the UK.
hopes
After that, there were still hopes for an early "return" of supersonic passenger aircraft. Aircraft designers talked about creating special engines, which would save fuel, despite the flight speed. We talked about improving the quality and optimizing the main avionics systems on such aircraft.
But, in 2006 and 2008, new regulations of the International Civil Aviation Organization were issued. They determined the latest (by the way, they are valid at the moment) standards for permissible aircraft noise during flight.
And supersonic aircraft, as you know, did not have the right to fly over populated areas, which is why. After all, they produced strong noise pops (also for reasons of the physical characteristics of the flight) when they moved at maximum speeds.
This was the reason that the "planning" of the "revival" of supersonic passenger aviation was somewhat slowed down. However, in fact, after the introduction of this requirement, aircraft designers began to think about how to solve such a problem. After all, it also had a place to be before, just the "ban" focused on it - the "problem of noise".
But what about today?
But ten years have passed since the last "ban". And planning smoothly turned into design. To date, several companies and government organizations are engaged in the creation of passenger supersonic aircraft.
What exactly? Russian: Central Aerohydrodynamic Institute (the one named after Zhukovsky), Tupolev and Sukhoi companies. Russian aircraft designers have an invaluable advantage.
The experience of Soviet designers and creators of the Tu-144. However, it is better to talk about domestic developments in this area separately and in more detail, which we propose to do next.
But not only the Russians are creating a new generation of supersonic passenger aircraft. This is also a European concern - Airbus, and the French company Dassault. Among the companies of the United States of America that work in this direction are Boeing and, of course, Lockheed Martin. In the land of the rising sun, the main organization that designs such an aircraft is the aerospace research agency.
And this list is by no means complete. At the same time, it is important to clarify that the vast majority of professional aircraft designers working in this area are divided into two groups. Regardless of country of origin.
Some believe that it is impossible in any way to create a "quiet" supersonic passenger aircraft, at the current level of technological development of mankind.
Therefore, the only way out is the design of a “simply fast” airliner. He, in turn, will move to supersonic speed in those places where it is allowed. And flying, for example, over settlements, return to subsonic.
Such "jumps", according to this group of scientists and designers, will reduce the flight time to the minimum possible, and not violate the requirements for noise effects.
Others, on the contrary, are full of determination. They believe that it is possible to deal with the cause of noise now. And they made a lot of efforts in order to prove that a supersonic airliner flying quietly is quite possible to build in the coming years.
And some more boring physics
So, when flying at a speed of more than Mach 1.2, the airframe of the aircraft generates shock waves. They are strongest in the tail and nose areas, as well as some other parts of the aircraft, such as, for example, on the edges of the air intakes.
What is a shock wave? This is a zone where the density, pressure and temperature of the air experience sharp jumps. They occur when moving at high speeds, faster than sound.
People who are standing on the ground at the same time, despite the distance, it seems that there is some kind of explosion. Of course, we are talking about those who are in relative proximity - under the place where the plane flies. That is why the flights of supersonic aircraft over cities were banned.
It is with such shock waves that representatives of the “second camp” of scientists and designers, who believe in the possibility of leveling this noise, are struggling.
If you go into details, then the reason for this is literally a “collision” with air at a very high speed. At the wave front, the pressure is sharply and strongly increased. At the same time, immediately after it, there is a drop in pressure, and then a transition to a normal pressure indicator (such as it was before the "collision").
However, the classification of wave types has already been carried out and potentially optimal solutions have been found. It remains only to complete the work in this direction and make the necessary adjustments to the aircraft designs, or create them from scratch, taking into account these amendments.
In particular, NASA experts have come to realize the need for structural changes in order to reform the characteristics of the flight as a whole.
Namely, changing the specifics of shock waves, as far as possible at the current technological level. What is achieved by restructuring the wave, due to specific design changes. As a result, the standard wave is considered as the N-type, and the one that occurs during the flight, taking into account the innovations proposed by experts, as the S-type.
And with the latter, the “explosive” effect of pressure change is significantly reduced, and people below, for example, in a city, if an airplane flies over it, even when they hear such an effect, then only as a “distant slam of a car door”.
Shape is also important
In addition, for example, Japanese aviation designers, not so long ago, in mid-2015, created an unmanned glider model D-SEND 2. Its shape is designed in a special way, allowing you to significantly reduce the intensity and number of shock waves that occur when the device flies at supersonic speed.
The effectiveness of the innovations proposed in this way by Japanese scientists was proven during the tests of D-SEND 2. Those were carried out in Sweden in July 2015. The course of the event was quite interesting.
The glider, which was not equipped with engines, was raised to a height of 30.5 kilometers. With the help of a balloon. Then he was thrown down. During the fall, he "accelerated" to a speed of Mach 1.39. The length of the D-SEND 2 itself is 7.9 meters.
After the tests, Japanese aircraft designers were able to confidently declare that the intensity of shock waves, when flying at a speed exceeding the speed of sound, is two times less than that of the Concorde.
What are the features of D-SEND 2? First of all, its nose is not axisymmetric. The keel is shifted towards it, and at the same time, the horizontal tail unit is set as all-moving. It is also located at a negative angle to the longitudinal axis. And at the same time, the tail ends are located lower than the attachment point.
The wing, smoothly connected to the fuselage, is made with a normal sweep, but stepped.
According to approximately the same scheme, now, as of November 2018, they are designing a passenger supersonic AS2. Professionals from Lockheed Martin are working on it. The customer is NASA.
Also, the project of the Russian VTS / SPS is now at the stage of improving the form. It is planned that it will be created with an emphasis on reducing the intensity of shock waves.
Certification and... more certification
It is important to understand that some projects of passenger supersonic aircraft will be implemented already in the early 2020s. At the same time, the rules established by the International Civil Aviation Organization, in 2006 and 2008, will still be in effect.
This means that if by that time there has not been a serious technological breakthrough in the field of “quiet supersonic”, then it is likely that aircraft will be created that will switch to speeds above one Mach, only in areas where this is allowed.
And after that, when the necessary technologies do appear, in such a scenario, many new tests will have to be carried out. In order for aircraft to be able to obtain permission to fly over populated areas. But these are only speculations about the future, today it is very difficult to say anything for sure on this score.
A question of price
Another issue mentioned earlier is cost. Of course, to date, many engines have already been created that are much more economical than those that were in operation twenty or thirty years ago.
In particular, those are now being designed that can provide the aircraft with movement at supersonic speeds, but at the same time do not “eat up” as much fuel as the Tu-144, or Concorde.
How? First of all, this is the use of ceramic composite materials, which provide a decrease in temperatures, and this is especially important in the hot zones of power plants.
In addition - the introduction of another, third, air circuit - in addition to external and internal. Leveling of a rigid coupling of a turbine with a fan, inside an aircraft engine, etc.
But nevertheless, even thanks to all these innovations, it cannot be said that supersonic flight, in today's realities, is economical. Therefore, in order for it to become accessible and attractive to the general population, work on improving engines is extremely important.
Perhaps - the actual solution will be a complete redesign of the structure - experts say.
By the way, it will not be possible to reduce the cost by increasing the number of passengers per flight. Since those aircraft that are being designed today (meaning, of course, supersonic aircraft) are designed to transport a small number of people - from eight to forty-five.
New engine - a solution to the problem
Of the latest innovations in this area, it should be noted the innovative jet, turbofan power plant, created this year, 2018, by GE Aviation. In October it was introduced under the name Affinity.
This engine is planned to be installed on the mentioned passenger AS2 model. There are no significant technological "novelties" in this type of power plants. But at the same time, it combines the features of jet engines with a large and small degree of bypass. What makes the model very interesting for installation on a supersonic aircraft.
Among other things, the creators of the engine claim that during testing it will prove its ergonomics. The fuel consumption of the power plant will be approximately equal to that which can be recorded with standard airliner engines that are currently in operation.
That is, this is an application that the power plant supersonic aircraft will consume approximately the same amount of fuel as a conventional airliner that is not capable of accelerating to speeds above Mach 1.
How this will happen is still difficult to explain. Since the design features of the engine, its creators do not currently disclose.
What can they be - Russian supersonic airliners?
Of course, today there are many specific projects for supersonic passenger aircraft. However, not everyone is close to implementation. Let's look at the most promising.
So - Russian aircraft manufacturers, who have inherited the experience of Soviet masters, deserve special attention. As mentioned earlier, today, within the walls of TsAGI named after Zhukovsky, according to its employees, the creation of the concept of supersonic passenger aircraft new generation.
The official description of the model, provided by the press service of the institute, mentions that it is a "light, administrative" aircraft, "with a low level of sonic boom." The design is carried out by specialists, employees of this institution.
Also, in the message of the TsAGI press service, it is mentioned that due to the special layout of the aircraft body and a special nozzle on which the noise suppression system is installed, this model will demonstrate the latest technological developments in the Russian aircraft industry.
By the way, it is important to mention that among the most promising projects of TsAGI, in addition to the described one, is a new configuration of passenger airliners, called the “flying wing”. It implements several particularly relevant improvements. Specifically, it makes it possible to improve aerodynamics, reduce fuel consumption, etc. But for non-supersonic aircraft.
Among other things, this institute has repeatedly presented ready-made projects that have attracted the attention of aviation enthusiasts from all over the world. Let's say - one of the latest - a model of a supersonic business jet that can cover up to 7,000 kilometers without refueling, and reach a speed of 1.8 thousand km / h. This was presented at the Gidroaviasalon-2018 exhibition.
"... designing is going on all over the world!"
In addition to the Russian ones mentioned, the following models are also the most promising. American AS2 (capable of speeds up to Mach 1.5). Spanish S-512 (speed limit - Mach 1.6). And also, currently under design in the US, Boom, from Boom Technologies (well, it will be able to fly at a maximum speed of Mach 2.2).
There is also the X-59, which is created by order of NASA, by Lockheed Martin. But it will be a flying scientific laboratory, not a passenger plane. And so far no one has planned to launch it into mass production.
The plans of Boom Technologies are interesting. Employees of this company declare that they will try to achieve the maximum reduction in the cost of a flight on supersonic airliners created by the enterprise. For example, they can approximate the price for a flight from London to New York. It is about 5000 US dollars.
For comparison, this is how much a ticket for a flight from the English capital to "New" York costs, on a regular, or "subsonic" plane, in business class. That is, the price of a flight on an airliner capable of flying at a speed of more than Mach 1.2 will be approximately equal to the cost of an expensive ticket for a plane that could not make the same fast flight.
However, Boom Technologies made a bet that it would not be possible to create a “quiet” supersonic passenger liner in the short term. Therefore, their Boom will fly at the maximum speed it can develop only over water spaces. And being above land, switch to a smaller one.
Given that the length of Boom will be 52 meters, at a time it will be able to carry up to 45 passengers. According to the plans of the company designing the aircraft, the first flight of this novelty should occur in 2025.
What is currently known about another promising project– AS2? It will be able to carry significantly fewer people - only eight to twelve people per flight. In this case, the length of the liner will be equal to 51.8 meters.
Over water, he, as planned, will be able to fly at a speed of Mach 1.4-1.6, and over land - 1.2. By the way, in the latter case, due to the special shape, the plane, in principle, will not form shock waves. For the first time, this model should take to the air in the summer of 2023. In October of the same year, the aircraft will perform its first flight across the Atlantic.
This event will be timed to coincide with a memorable date - the twentieth anniversary of the day the Concordes flew over London for the last time.
Moreover, the Spanish S-512 will take to the skies for the first time no later than at the end of 2021. And deliveries of this model to customers will begin in 2023. The maximum speed of this aircraft is Mach 1.6. It is possible to accommodate 22 passengers on board. The maximum flight range is 11.5 thousand km.
The client is the head of everything!
As you can see, some companies are trying very hard to complete the design and start building aircraft - as quickly as possible. For whose sake are they ready to hurry so much? Let's try to explain.
So, during 2017, for example, the volume of air passenger traffic amounted to four billion people. Moreover, 650 million of them flew on long distance, having traveled from 3.7 to thirteen hours. Further - 72 million out of 650, moreover, they flew first, or business class.
It is these 72,000,000 people, on average, that those companies that are engaged in the creation of supersonic passenger aircraft are counting on. The logic is simple - it is possible that many of them will not mind paying a little more for a ticket, with the condition that the flight will be about twice as fast.
But, even despite all the prospects, many experts reasonably believe that the active progress of supersonic aviation, created for the transport of passengers, can begin after 2025.
In support of this opinion, the fact that the aforementioned “flying” laboratory X-59 will take to the air for the first time only in 2021 testifies. And why?
Research and perspectives
The main purpose of its flights, which will take place over several years, will be the collection of information. The fact is that this aircraft must fly over various settlements at supersonic speed. Residents of these settlements have already expressed their consent to the testing.
And after the laboratory plane completes the next "experimental flight", the people living in those settlements, over which she flew, should tell about the "impressions" that they received during the time when the airliner was over their heads. And especially clearly express how the noise was perceived. Did it affect their livelihoods, etc.
The data collected in this way will be transferred to the Federal Aviation Administration in the United States. And after their detailed analysis by specialists, it is possible that the ban on flights of supersonic airliners over populated areas of land will be canceled. But in any case, this will happen no earlier than 2025.
In the meantime, we can watch the creation of these innovative aircraft, which will soon mark the birth of a new era of supersonic passenger aviation with their flights!
