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S-51 Supersonic Passenger Aircraft

S-51 Supersonic Passenger Aircraft As part of the program for the creation of a 2nd generation supersonic passenger aircraft (SPS-2), TsAGI and Sukhoi Design Bureau carried out joint development of a 21st century intercontinental supersonic business aircraft (MSDS) with a flight range of L = 8000 km. Such MSDS could carry out non-stop flights on the main transatlantic and Pacific routes: New York - Moscow, London - Washington, Tokyo - Seattle, etc. With one intermediate landing, the MSDS will allow realizing flights between almost any two capitals of the world, providing even a one-hour intermediate stop, which saves significant time compared to subsonic business aircraft.

Studies of the concept of supersonic passenger aircraft - the "small" (administrative) S-21and the "large" (passenger) S-51 began at the Design Bureau named after P.O. Sukhoi in 1989 on the initiative of the General Designer MP Simonov. The work was carried out under the direct supervision of the Deputy General Designer M. A. Poghosyan. S-21 was supposed to carry 5-8, and S-51 - 30-50 people.

In the business administrative version, the MSDS is intended mainly for transportation of high-ranking state and business people, therefore, ensuring the reliability and safety of flight and comfort are of particular importance to the MSDS.

In the MSDS version with a non-circular fuselage with a maximum width of 2.8 m, 8-10 passengers in the luxury class or 27-30 passengers in the economy class can be accommodated. Ensuring such maximum passenger capacity significantly expands the possibilities of using MSDS, and, consequently, its market.

Just as for long-haul supersonic airplanes, the most important requirement for MSDS is to ensure the dual-mode aircraft, i.e. the possibility of performing equally effective range flight at supersonic (Mkr ~ 2) and transonic (M ~ 0.93) cruising modes. The specified requirement is dictated by the restrictions on sound shock, allowing the execution of supersonic flights only over water spaces or in corridors over uninhabited land such as deserts and polar regions. Thus, some MSDS routes may turn out to be combined, including subsonic sections of long-range flight. The requirement of dual-mode has a significant impact on the choice of the aerodynamic configuration of the SPS-2, and in particular on the choice of the shape of the wing in plan, as well as on the choice of type of engines of the power plant.

Fundamental for MSDS is the choice of the number of engines of the power plant. The advantage of the four-engine MSDS variant is that the failure of one engine on take-off can be almost completely compensated by the corresponding forcing of the other three engines. The possibility of forcing is due to the usual oversized engines for take-off modes for MSDS. Therefore, for MSDS with four engines, the case of failure of one engine on takeoff is no longer calculated. Similarly, failure of one engine in cruise mode will allow completing the flight at the required range, since in this case there are no restrictions on the duration of the flight with engine failure, which are superimposed on a twin-engine aircraft. Thus, the four-engine version provides significantly greater reliability and flight safety.

The most effective aerodynamic method for coordinating aerodynamic quality values ??in subsonic and supersonic cruise flight modes is to select the appropriate wing shape in plan and use adaptive elevons and wing socks. The TsAGI recommended wing for MSDS is designed to provide approximately the same kilometer fuel consumption for the two indicated flight modes. In this case, changes in the full flight range caused by a temporary transition from supersonic flight mode to subsonic and vice versa are small.

The selected wing ensures the achievement of a small difference between the positions of the aerodynamic focus at subsonic and supersonic speeds. This allows implementing a tailless flight in a supersonic cruising mode with a small margin of longitudinal static stability and ensuring longitudinal balancing in this mode at virtually zero elevon deviation angles, which means that there is no loss of aerodynamic quality for balancing. When designing the MSDS, it should be borne in mind that environmental restrictions on noise on the side of the runway and at the flyover control point must be met. It can be assumed that the MSDS should meet the requirements of FAR-36, Ch. 3, appendix 16 (volume 1). The main source of noise during take-off is the jet of a jet engine. Therefore, the main task of reducing engine noise is to reduce the exhaust flow rates. Preliminary studies performed at TsAGI and TsIAM show that the use of turbofan engines with a bypass ratio of m 0= 0.9-1.0 in combination with traction control on the take-off trajectory and measures aimed at improving aerodynamic quality, is a promising direction for solving the MSDS noise problem in the airport area. This approach places increased demands on the value of aerodynamic quality at the take-off stage. To increase the aerodynamic quality on takeoff, it is necessary to reduce the C UAZ values , which can be realized by reducing the wing load to values ??of G o / S ~ 310 kg / m 2.

A distinctive feature of the recommended MSDS layout is the use of a wing of complex shape in plan with a base wing of relatively low sweep. This allows increasing the total elongation to 2.2 (compared with 1.67 for SPS-1 Tu-144 ) and thereby increase the aerodynamic quality and load-bearing properties of the wing during take-off and landing. The MSDS layout provides for the use of deflectable socks in combination with downward deflectable elevons along the trailing edge of the wing. Such wing mechanization allows one to significantly increase the value of the Sua lifting force coefficient at a fixed angle of attack a = const and the aerodynamic quality at a fixed value Cya = const. In the calculated take-off mode, the rational range of elevation deviation angles is ev = 10 -12 . In order to improve aerodynamic performance in the take-off configuration, it is recommended to use small degrees of static longitudinal instability.

Studies show that the current level of aerodynamic design allows implementing the layout of the MSDS with high levels of maximum aerodynamic quality at cruising speeds of K max = 13.3 and 8.3 at M = 0.93 and 2.0, respectively. The developed MSDS arrangement allows one to realize a flight range of L ~ 8000 km with a cruising number of M = 2 with an air navigation fuel reserve (G anz = 5.6 t) sufficient for the standard removal of a reserve aerodrome (370 km), a half-hour waiting for landing and 4% compensatory fuel supply. Almost the same range is realized in the subsonic cruising mode (M = 0.93) and on routes with different flight modes.

Initially, the maximum take-off weight (MVM) of the S-51 was estimated at 75 tons.

In 1991, the project was revised: the aircrafts MVM increased to 90 tons, and the number of passengers carried in the usual cabin configuration grew to 58. Its first flight was expected in 2005, and commissioning in 2010.

POWER INSTALLATION of the S-51 aircraft includes 4 turbofan engines Aviadvigatel D-21A1 with a total thrust of 38,000 kgf. The engines are located in pairs under the wing. In the future, a significant reduction in engine noise level is expected, which will provide more comfortable conditions in the cabin.

DesignAOOT OKB Sukhoi
DesignationS-51
Year of constructionproject 1990-91
Type ofSupersonic Passenger Aircraft
Crew2 (?)
Number of passengers68
Geometric and mass characteristics
Wing span, m
Aircraft length, m
Take-off weight kg90700
Empty weight, kg22560
Power point
Engine number4
EngineDTRDF D-21A1
Engine thrust (starting), kgf9500 (7500?)
Flight data (estimated)
Cruising speed, km / h (M =)supersonic2125 (2.0)
subsonic1015 (0.95)
Flight range, km9200
Required runway length, m2500
S-51 Supersonic Passenger Aircraft




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Page last modified: 12-12-2019 19:05:04 ZULU