Lyulka AL-21

AL-21
Lyulka AL-21F3 engine, Airforce Museum of the Bundeswehr; Berlin-Gatow
Type	Turbojet
Manufacturer	Lyulka
Major applications	Sukhoi Su-17 Sukhoi Su-24 Yakovlev Yak-38

The Lyulka AL-21 is an axial flow turbojet engine created by the Soviet Design Bureau named for its chief designer Arkhip Lyulka.

Design and development

The AL-21 is similar in power and technology to the General Electric J79 first flown in 1955 which was first engine for supersonic flight using the variable stator.^[1] Western analysts believe they were designed by reverse engineering a J-79 engine which was most widely used on the F-4 Phantom from a plane shot down in Vietnam.^[2]

After the fall of Soviet Union, it's became clear that AL-21F3 turbojet engine is different and more advanced design than J-79. It sucks in more air, compresses it more, and burns it hotter. AL-21F3 is a later design and superior in all respects. Its compressor is much more advanced getting more compression from less stages.^{[3] [4]} It is generally described as being in the "third generation" of Soviet gas turbine engines which are characterized by high thrust-to-weight ratios and the use of turbine air cooling.^[5]

The AL-21 entered service in the early 1960s. With later marks AL-21F3 it was used in the Sukhoi Su-17, Sukhoi Su-24, Ground-attack variant Mikoyan-Gurevich MiG-23, and Sukhoi T-10 (Sukhoi Su-27 prototype). A non-afterburning version powered the Yakovlev Yak-38 VTOL fighter.

Specifications (AL-21F3)

General characteristics

• Type: Afterburning turbojet
• Length: 5,300 mm (209 in)
• Diameter: 1,000 mm (39 in)
• Dry weight: 1,700 kg (3,740 lb)

Components

• Compressor: 14-stage axial compressor with variable stator blades
• Turbine: Two-stage high pressure, single-stage low pressure

Performance

• Maximum thrust:
  
• 76.4 kN (17,175 lbf) dry
• 109.8 kN (24,675 lbf) with afterburner
• Overall pressure ratio: 14.75:1
• Turbine inlet temperature: 1,100 °C (2,000 °F)
• Specific fuel consumption:
  
  • 77.5 kg/(h·kN) (0.76 lb/(h·lbf)) at idle
  • 87.7 kg/(h·kN) (0.86 lb/(h·lbf)) at maximum military power
  • 189.7 kg/(h·kN) (1.86 lb/(h·lbf)) with afterburner
• Thrust-to-weight ratio: 64.7 N/kg (6.6:1)
• Life expectancy: 1,800 hours

See also

Related lists

• List of aircraft engines

References

1. Aircraft Propulsion and Gas Turbine Engines By Ahmed F. El-Sayed p. 16
2. The Su-24 attack interceptor: jack of two trades, master of both
3. http://forum.keypublishing.com/showthread.php?113202-J79-versus-AL-21
4. http://www.motor-lutsk.com.ua/production_en.html
5. Sosounov, V.A. (1990). The Development of Aircraft Power Plant Construction in the USSR and the 60th Anniversary of CIAM. AlAA/ASME/SAE/ASEE 26th Joint Propulsion Conference, July 16–18, 1990. Orlando, Florida. AIAA-90-2761.

External links

• Page of the engine at Russian Aircraft Encyclopedia