AL-31F

Engine design began in 1973, the first tests passed in 1977, state tests were completed in 1985. Since 1981, AL-31 engines have been manufactured at UMPO ( Ufa ) and MMPP Salyut ( Moscow ).

After the death of A.M. Lyulka in 1984, the work on the engine and its modifications was headed by General Designer V.M. Chepkin . Currently OKB them. The cradle (Moscow) is part of UMPO .

The estimated cost of one AL-31F engine (as of 2008) is 96.4 million rubles ^[2] .

Since 2013, the engine has been assembled within the framework of the UEC “combat aircraft engines” division, the Salyut gas turbine engineering center is responsible for the hot part, and for the cold part and assembly of UMPO , OMO.

AL-31F is a basic dual-circuit twin-shaft turbojet engine with a mixture of flows of internal and external circuits behind the turbine, an afterburner common to both circuits and an adjustable supersonic all-mode jet nozzle. The engine is modular.

It consists of a 4-stage axial low-pressure compressor, with an adjustable inlet guide vane (VNA), a 9-stage axial high-pressure compressor, with an adjustable VNA and guiding devices of the first two stages, high-pressure and low-pressure turbines - axial single-stage; blades of turbines and nozzle apparatus cooled (film cooling). The main combustion chamber is annular.

Titanium alloys (up to 35% of the mass) and heat-resistant steels are widely used in the engine design. Turbine blades have cavities in the form of labyrinths, for cooling, gases are supplied from the disk to the blade and pass through the holes along the edges (film air cooling), a fir-tree shank is used to fasten the blade to the disk. The shaft of each rotor is supported by 2 roller and 1 ball bearing . After the turbine, an 11-blade mixer is installed. To ensure stable operation of the FC, a turbine coke is installed that smoothly transfers the flow from the annular to the circular cross section, with anti-vibration holes, and anti-vibration longitudinal screens are installed in the afterburner.

The engine has an electric ignition system. The starter system can start the engine both on the ground and in flight. To start the engine on the ground, a starting device is used located in a remote box of the engine. In normal engine operation, to save fuel, turbine cooling is partially disabled.

The use of adjustable VNA KND and KVD gives a higher resistance to surging , in practice this meant that the engines will remain operational when the aircraft gets into a tailspin and when launching missiles. The engine in flight can be used in all modes without restrictions. The response time from the idle mode to the “maximum” mode at a low altitude of 3-5 seconds, at an average height of 5 s, at a high altitude of 8 s. The nominal rotational speed of the high pressure rotor is 13,300 rpm.

AL-31F

The basic version of the engine is used on Su-27 fighters and its modifications. The originally assigned serial AL-31F resource was only 100 hours, at the request of the USSR Air Force at 300 hours, but then over time it was brought up to 1,500 hours. Overhaul life at maximum operating modes ranged from 5 to 15 hours. The maximum number of start-up cycles (TAC) is 300. The AL-31 engines are produced by the enterprises of UMPO and the Salyut gas turbine construction center .

Features

• Length: 4945 mm
• Inlet Diameter: 905 mm
• Weight: 1488 kg
• Afterburner traction on afterburner : 12 500 kgf
• Thrust at maximum: 7770 kgf
• Gas temperature in front of the turbine: 1665 K
• Compression ratio: 23: 1
• Bypass Degree : 0.56
• Air Consumption: 112 kg / s
• Specific Fuel Consumption:
  • cruising mode: 0.67 kg kgf / h
  • in maximum mode: 0.75 kg kgf / h
  • in full fast and furious mode: 1.92 kg kgf / h

A large number of modifications have been developed on the basis of AL-31F.

AL-31FP

The main difference from the base engine AL-31F is the controlled thrust vector , which significantly increases the maneuverability of the aircraft. Changing the vector is possible at an angle of up to ± 15 ° in the vertical plane. "FP" means afterburner rotary. The engine was developed by NPO Saturn and is manufactured at UMPO.

AL-31FP engines are installed on Su-30SM , Su-30MKI fighters.

• Length 4942 mm
• Input diameter 905 mm
• Outer diameter 1277 mm
• Weight 1520 kg

P-32

Forced AL-31F engine for the record P-42 aircraft , created on the basis of the Su-27 . Afterburner engine thrust was increased to 13600 kgf.

AL-31F3

AL-31F engine option for the Su-33 carrier-based fighter. Unlike the basic AL-31F, an additional special mode (OR) with a thrust of 12,800 kgf appeared, which is briefly used when taking off an aircraft from a deck with full combat load or during emergency departure to the second circle.

AL-31FN

Modification AL-31F with a lower arrangement of the box of units for the Chinese fighter Chengdu J-10 . It has an increased traction force of 200 kgf compared with the basic version. Designed by MMPP Salute. China purchased a total of 399 units of AL-31FN in the amount of $ 500 million in 2013 ^[3] .

The R&D contract between China and Russia was signed in 1992, and financing was also provided by China. In 1994, the engine was finally designed.

Initially, the engine was developed jointly by NPO Saturn with the MMPP Salyut, but after 1998 the MMPP Salyut developed the documentation and set up serial production of the AL-31FN independently. In 1999, the Federal Agency for the Protection of the Results of Intellectual Activity (FAPRID) was created under the Ministry of Justice. In an effort to delegitimize the rights of the developer, the Director General of MMPP Salyut Yuri Eliseev managed to sign a license agreement with FAPRID (No. 1-01-99-00031), which was the very first contract of this kind concluded by the newly created agency. Referring to it, Salute considers the 1998 license agreement with Saturn to be void.

AL-31F M1

The upgraded AL-31F MMPP Salute engine with a KND-924-4 four-stage low-pressure compressor with a diameter increased from 905 to 924 mm, providing 6% more air flow, as well as a more advanced digital automatic control system (compression ratio 3.6). The gas temperature in front of the turbine of this engine is increased by 25 ° C. The engine is dual-circuit, the first circuit passes through the “jacket” for cooling, then it is mixed behind the turbine with a hot twin-shaft secondary circuit.

The first flight on January 25, 2002, mass-produced since 2006 for fighters of the Su-27 family ^[4] , is installed without any modifications to any fighters, including those from the early years of production, are installed on 1 Su-27SM / SM2 regiment. It was adopted by the Russian Air Force in 2007 ^[5]. It has an increased traction force (13,300 kgf), an overhaul life of 1,000 hours ^[6] , and an assigned resource of 2,000 hours while maintaining overall dimensions and weight. Specific fuel consumption has been reduced. It has a modification with a controlled thrust vector, with a resource of 800 hours ^[6] .

• Length 4.945 m
• Maximum outer diameter 1.14 m
• Weight 1520 kg

AL-31F M2

The AL-31FM2 engine is a turbojet dual-circuit engine based on the AL-31F. The turbine blades with perforations along the edges are made by casting, the temperature before entering the turbine is increased by 100 ° C in comparison with the AL-31F. The engine thrust in a special mode is 14 500 kgf ^[7] , in the full boost mode 14 100 kgf ^[8] . The assigned resource of the modernized engine exceeds 3,000 hours. The engine has minimal differences from the series 3, 20 and 23. The traction characteristics are increased while the specific fuel consumption is reduced, including in the afterburner modes. It does not require refinement of the aircraft side when staging on aircraft such as Su-27, Su-30, Su-34, unlike engines of other series. In 2012, the engine was first shown at the 2nd International Forum "Engineering Technologies 2012 (TBM-2012) ^[9] . SLI is planned for 2013.

AL-31F M3

The 3rd stage of the modernization of the AL-31F MMPP Salyut, an additional three-stage KND with wide chord spatially profiled blades and an increased degree of pressure increase to 4.2 (KND-924-3) is additionally installed, which allows to increase thrust up to 15,300 kgf (obtained from static tests) . The blades and the disk of the 3-stage low pressure switch are a single unit (blisk), instead of 9 stages of the high pressure switch it is planned to reduce the number to 6 ^[10] . Since 2002, the engine has been in bench tests.

AL-41F1S (Product 117C)

The engine of the "first stage" for the 4 ++ Su-35BM generation fighter, adopted by the Russian Air Force (now VKS) under the designation Su-35S, with a thrust of 14,000 kgs in full afterburner (14,500 in emergency mode) ^{[11] [12]} . It is created on the basis of AL-31F, AL-31FP and AL-41F engines. Despite the scheme similar to AL-31F, the engine consists of new parts by 80% ^[13] . It is distinguished from its predecessors by increased thrust (14,000 ^[14] kgf vs. 12,500 for AL-31F), a fully digital control system, a plasma ignition system, a new compressor with a larger diameter, a significantly increased service life (4,000 hours against 1,000 in AL-31F) and improved consumables characteristics ^[13] . The gearbox is located on top of the engine. The development cost amounted to 3 billion rubles ^[15] .

The increase in thrust was obtained by increasing the diameter of the compressor from 905 to 932 mm ^[16] . Engine length increased to 4990 mm. Traction in emergency mode - 14 500, at a maximum - 8800 kgf.

NPO Saturn in 2008 conducted 200-hour tests, including 16 hours - “hot” ^[17] .

AL-31ST

The “ground” stationary modification AL-31F with a capacity of 16 MW ^[18] for use as a drive for gas pumping stations.

• AL-31F on the website of NPO Saturn
• AL-31F M1 on the site of the MMPP Salyut
• AL-31F /airwar.ru/