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| J85 | |
|---|---|
 | |
| A General Electric J85-GE-21A, the most powerful variant of the type. | |
| Type | Turbojet |
| National origin | United States |
| Manufacturer | General Electric |
| First run | 1950s |
| Major applications | Cessna A-37 Dragonfly Canadair CT-114 Tutor Northrop F-5 Northrop T-38 Talon |
| Variants | General Electric CJ610 |
| Developed into | General Electric CF700 |
The General Electric J85 is a small single-shaft turbojet engine. Military versions produce up to 3,500 lbf (16 kN ) of thrust dry; afterburning variants can reach up to 5,000lbf (22kN). The engine, depending upon additional equipment and specific model, weighs from 300 to 500 pounds (140 to 230kg). It is one of GE's most successful and longest in service military jet engines, with the civilian versions having logged over 16.5 million hours of operation. The United States Air Force plans to continue using the J85 in aircraft through 2040. [1] Civilian models, known as the CJ610, are similar but supplied without an afterburner and are identical to non-afterburning J85 variants, while the CF700 adds a rear-mounted fan for improved fuel economy.
Contents
- Design and development
- Iranian reverse engineering
- Variants
- Applications
- Other
- Specifications (J85-GE-21)
- See also
- References
- External links
Design and development
The J85 was originally designed to power a large decoy missile, the McDonnell ADM-20 Quail. The Quail was designed to be released from a B-52 Stratofortress in-flight and fly for long distances in formation with the launch aircraft, multiplying the number of targets facing the SA-2 surface-to-air missile operators on the ground. This mission demanded a small engine that could nevertheless provide enough power to keep up with the jet bomber. Like the similar Armstrong Siddeley Viper being built in the UK, the engine on a Quail drone had no need to last for extended periods of time, so therefore could be built of low-quality materials.
The fit was a success on the Quail, but again like the Viper it was later built with normal grade materials and subsequently used to power small jet aircraft, including the Northrop T-38 Talon, Northrop F-5, Canadair CT-114 Tutor, and Cessna A-37 Dragonfly light attack aircraft. More recently, J85s have powered the Scaled Composites White Knight aircraft, the carrier for the Scaled Composites SpaceShipOne spacecraft, and the Me 262 Project.
The basic engine design is quite small, about 17.7 inches (45cm) in diameter, and 45.4 inches (115cm) long. It features an eight-stage axial-flow compressor powered by two turbine stages, and is capable of generating up to 2,100lbf (9.3kN) of dry thrust, or more with an afterburner. At full throttle at sea level, this engine, without afterburner, consumes approximately 400 US gallons (1,500L) of fuel per hour. At cruise altitude and power, it consumes approximately 100USgal (380L) per hour.
Several variants were produced.
The most advanced variant in the J85 series is the J85-21 model designed specifically for the F-5E/F during its development process. [2]
The J85-21 design replaces AM 355 chromium nickel molybdenum stainless steel alloy, used by previous J85 models for compressor rotors and blades, with a titanium alloy. Its inlet diameter was increased from 17.7in (45cm) to 20.8in (53cm), and it included an added stage ahead of the base 8-stage compressor for a total of 9 stages. Its multiple disk rotors were replaced with a single-spool rotor, thus improving dry thrust to 3,600lbf (16kN) and wet thrust to 5,000lbf (22kN) while reducing mechanical complexity along with the weight gain of the J85-21 model. [2]
More than 12,000 J85 engines had been built by the time production ended in 1988. [3]
Iranian reverse engineering
See also: Iran Aviation Industries Organization
The Iranian Ministry of Defense constructed a new engine based on the General Electric J85-GE-21B named "OWJ" and presented it at a defense exhibition on 22 August 2016. [4] [5] [6] [7]
The Owj engine has been used in several Iranian products like Kowsar, Saeghe and Azarakhsh fighter jets or Yasin training jet. [8] [9]
Variants
- J85-GE-1
- 1,900–2,100lbf (8.5–9.3kN) thrust [2]
- J85-GE-2
- 2,850lbf (12.7kN) thrust
- J85-GE-3
- 2,450lbf (10.9kN) thrust
- J85-GE-4
- 2,950lbf (13.1kN) thrust
- J85-GE-5
- 2,400lbf (11kN) military thrust; 3,600lbf (16kN) afterburning thrust
- J85-GE-5A
- 3,850lbf (17.1kN) afterburning thrust
- J85-GE-7
- 2,450lbf (10.9kN) thrust
- J85-GE-12
- J85-GE-13
- 2,720lbf (12.1kN), military thrust; 4,080lbf (18.1kN) afterburning thrust [10]
- J85-GE-15
- 4,300lbf (19kN) afterburning thrust [2]
- J85-CAN-15
- Orenda manufactured J85-GE-15 for the Canadair CF-116 4,300lbf (19kN) afterburning thrust
- J85-GE-17A
- 2,850lbf (12.7kN) thrust [11]
- J85-GE-19
- J85-GE-21A
- 3,500lbf (16kN) military thrust; 5,000lbf (22kN) afterburning thrust. [10]
- J85-GE-J1A
- 5,000lbf (22kN) afterburning thrust
- J85-GE-J2
- 2,850lbf (12.7kN) thrust.
- J85-GE-J4
- J85-CAN-40
- Manufactured by Orenda for the Canadair CT-114 Tutor, 2,650lbf (11.8kN) thrust
Applications
- Bell X-14A/B
- Boom XB-1 demonstrator [12]
- Canadair CT-114 Tutor
- Canadair CF-5
- Cessna A-37 Dragonfly
- HESA Yasin (without afterburner)
- HESA Kowsar (with afterburner)
- Fairchild C-123 Provider
- Fairchild AC-119K
- Fiat G.91Y
- Lockheed Have Blue
- McDonnell ADM-20 Quail decoy missile
- North American Rockwell OV-10 Bronco - OV-10B(Z) target tug variant, the engine in addition to its turboprops [13]
- North American T-2 Buckeye
- Northrop F-5
- Northrop T-38 Talon
- Ryan MQM-34D Mod II target drone
- Ryan XV-5 Vertifan
- Saab 105Ö
- Scaled Composites White Knight
Other
- American Challenge water speed record jet-powered boat - Two J85-GE-21s [14]
- Hermeus experimental turbine-based combined cycle "Chimera" turboramjet engine - J85-21 turbojet core [15]
Specifications (J85-GE-21)
Data from [16] [17] [18] [19]
General characteristics
- Type: afterburning turbojet engine
- Length: 112.5in (286cm)
- Diameter: 20.8in (53cm) inlet
- Dry weight: 684lb (310kg)
Components
- Compressor: single-spool 9 axial stages
- Combustors: annular
- Turbine: 2 stages
- Fuel type: jet fuel
Performance
- Maximum thrust: 3,600lbf (16kN) dry thrust / 5,000lbf (22kN) afterburner thrust
- Overall pressure ratio: 8.3:1 (J85-21 A~C model)
- Air mass flow: 53lb (24kg) per second
- Turbine inlet temperature: 1,790°F (980°C)
- Specific fuel consumption: 1.24 lb/(lbf⋅h) or 35 g/(kN⋅s) dry thrust / 2.13 lb/(lbf⋅h) or 60 g/(kN⋅s) afterburner thrust
- Thrust-to-weight ratio: 5.25 dry / 7.3 afterburner
See also
Related development
- General Electric CJ610
- General Electric CF700
Comparable engines
- Armstrong Siddeley Viper
- Continental J69
- Fairchild J83
- Rolls-Royce Soar
Related lists
- List of aircraft engines
Related Research Articles
An afterburner is an additional combustion component used on some jet engines, mostly those on military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, takeoff, and combat. The afterburning process injects additional fuel into a combustor in the jet pipe behind the turbine, "reheating" the exhaust gas. Afterburning significantly increases thrust as an alternative to using a bigger engine with its attendant weight penalty, but at the cost of increased fuel consumption which limits its use to short periods. This aircraft application of "reheat" contrasts with the meaning and implementation of "reheat" applicable to gas turbines driving electrical generators and which reduces fuel consumption.
The General Electric F110 is an afterburning turbofan jet engine produced by GE Aerospace. It was derived from the General Electric F101 as an alternative engine to the Pratt & Whitney F100 for powering tactical fighter aircraft, with the F-16C Fighting Falcon and F-14A+/B Tomcat being the initial platforms; the F110 would eventually power new F-15 Eagle variants as well. The engine is also built by IHI Corporation in Japan, TUSAŞ Engine Industries (TEI) in Turkey, and Samsung Techwin in South Korea as part of licensing agreements.
The General Electric F101 is an afterburning turbofan jet engine. It powers the Rockwell B-1 Lancer strategic bomber fleet of the USAF. In full afterburner it produces a thrust of more than 30,000 pounds-force (130kN). The F101 was GE's first turbofan with an afterburner.
The Pratt & Whitney TF30 is a military low-bypass turbofan engine originally designed by Pratt & Whitney for the subsonic F6D Missileer fleet defense fighter, but this project was cancelled. It was later adapted with an afterburner for supersonic designs, and in this form it was the world's first production afterburning turbofan, going on to power the F-111 and the F-14A Tomcat, as well as being used in early versions of the A-7 Corsair II without an afterburner. First flight of the TF30 was in 1964 and production continued until 1986.
The Pratt & Whitney F100 is an afterburning turbofan engine designed and manufactured by Pratt & Whitney to power the U.S. Air Force's "FX" initiative in 1965, which became the F-15 Eagle. The engine was to be developed in tandem with the F401 which shares a similar core but with the fan upscaled for the U.S. Navy's F-14 Tomcat, although the F401 was later abandoned due to costs and reliability issues. The F100 would also power the F-16 Fighting Falcon for the Air Force's Lightweight Fighter (LWF) program.
The General Electric J79 is an axial-flow turbojet engine built for use in a variety of fighter and bomber aircraft and a supersonic cruise missile. The J79 was produced by General Electric Aircraft Engines in the United States, and under license by several other companies worldwide. Among its major uses was the Lockheed F-104 Starfighter, Convair B-58 Hustler, McDonnell Douglas F-4 Phantom II, North American A-5 Vigilante and IAI Kfir.
The General Electric/Allison J35 was the United States Air Force's first axial-flow compressor jet engine. Originally developed by General Electric in parallel with the Whittle-based centrifugal-flow J33, the J35 was a fairly simple turbojet, consisting of an eleven-stage axial-flow compressor and a single-stage turbine. With the afterburner, which most models carried, it produced a thrust of 7,400lbf (33kN).
The Rolls-Royce Avon was the first axial flow jet engine designed and produced by Rolls-Royce. Introduced in 1950, the engine went on to become one of their most successful post-World War II engine designs. It was used in a wide variety of aircraft, both military and civilian, as well as versions for stationary and maritime power.
The General Electric J47 turbojet was developed by General Electric from its earlier J35. It first flew in May 1948. The J47 was the first axial-flow turbojet approved for commercial use in the United States. It was used in many types of aircraft, and more than 30,000 were manufactured before production ceased in 1956. It saw continued service in the US military until 1978. Packard built 3,025 of the engines under license.
The General Electric F404 and F412 are a family of afterburning turbofan engines in the 10,500–19,000lbf (47–85kN) class. The series is produced by GE Aerospace. Partners include Volvo Aero, which builds the RM12 variant. The F404 was developed into the larger F414 turbofan, as well as the experimental GE36 civil propfan.
The Lyulka AL-7 was a turbojet designed by Arkhip Mikhailovich Lyulka and produced by his Lyulka design bureau. The engine was produced between 1954 and 1970.
The General Electric CJ610 is a non-afterburning turbojet engine derived from the military J85, and is used on a number of civilian business jets. The model has logged over 16.5 million hours of operation. Civilian versions have powered business jets such as the Learjet 23 and the Hamburger Flugzeugbau HFB 320 Hansa Jet. The engines are also used in the flyable Messerschmitt Me 262 reproductions built by the Me 262 Project in the United States.
The Westinghouse J40 was an early high-performance afterburning turbojet engine designed by Westinghouse Aviation Gas Turbine Division starting in 1946 to a US Navy Bureau of Aeronautics (BuAer) request. BuAer intended to use the design in several fighter aircraft and a bomber. However, while an early low-power design was successful, attempts to scale it up to its full design power failed, and the design was finally abandoned, deemed a "fiasco" and a "flop".
The Allison J71 was a single spool turbojet engine, designed and built in the United States. It began development in 1948 as a much modified J35, originally designated J35-A-23.
The Pratt & Whitney JT12, is a small turbojet engine. The Pratt & Whitney T73 is a related turboshaft engine.
The Fairchild J83 turbojet was developed starting in 1955 to power cruise missiles used as un-armed decoys for bomber aircraft. The engine's development was terminated in November 1958.
The General Electric YJ93 turbojet engine was designed as the powerplant for both the North American XB-70 Valkyrie bomber and the North American XF-108 Rapier interceptor. The YJ93 was a single-shaft axial-flow turbojet with a variable-stator compressor and a fully variable convergent/divergent exhaust nozzle. The maximum sea-level thrust was 28,800lbf (128kN).
The General Electric J87 was a nuclear-powered turbojet engine designed to power the proposed WS-125 long-range bomber. The program was started in 1955 in conjunction with Convair for a joint engine/airframe proposal for the WS-125. It was one of two nuclear-powered gas turbine projects undertaken by GE, the other one being the X39 project.
The Westinghouse J46 is an afterburning turbojet engine developed by the Westinghouse Aviation Gas Turbine Division for the United States Navy in the 1950s. It was primarily employed in powering the Convair F2Y Sea Dart and Vought F7U Cutlass. The engine also powered the land speed-record car known as the Wingfoot Express, designed by Walt Arfons and Tom Green It was intended to power the F3D-3, an improved, swept-wing variant of the Douglas F3D Skyknight, although this airframe was never built.
The General Electric J73 turbojet was developed by General Electric from the earlier J47 engine. Its original USAF designation was J47-21, but with innovative features including variable inlet guide vanes, double-shell combustor case, and 50% greater airflow was redesignated J73. Its only operational use was in the North American F-86H.
References
- ↑ 2001-04-17T00:00:00+01:00. "T-38 engine upgrades set to extend trainer's life to 2040". Flight Global. Retrieved 2020-05-20.
{{cite web}}: CS1 maint: numeric names: authors list (link) - 1 2 3 4 Defense Technical Information Center Compilation Part Notice dtic.mil
- ↑ "General Electric J85-GE-17A Turbojet Engine, Cutaway". Archived from the original on 2014-02-03. Retrieved 2014-01-28.
- ↑ "موتورهای هوایی مورد نیاز ایران، ایا راهی برای برون رفت از بحران هست؟". April 3, 2018.
- ↑ "Iran Upgrades".
- ↑ "Iran's U.S.-Made F-5 Jets Could Fly Until the 2040s". 11 February 2019.
- ↑ "Military Knowledge: Kowsar Fighter Jet + Images – Islamic World News". 30 June 2020.
- ↑ "Kowsar; fighter with distinctive features". iranpress.com. Retrieved 2023-04-26.
- ↑ Network, Frontier India News (2023-03-11). "Iran launches production of HESA Yasin Light jet powered trainer aircraft". World News briefs. Retrieved 2023-04-26.
- 1 2 Roskam, Jan (November 28, 1985). Airplane Design. DARcorporation. ISBN 9781884885563 – via Google Books.
- ↑ "Turbojet Engine, Cutaway, General Electric J85-GE-17A | National Air and Space Museum". airandspace.si.edu.
- ↑ Guy Norris (Jul 10, 2018). "Boom Focuses On Derivative Engines For Supersonic Airliner Plan". Aviation Week & Space Technology.
- ↑ "OV10B". www.germanwing.de.
- ↑ "400 Mph On Water". Popular Mechanics. Archived from the original on September 30, 2007.
- ↑ "CHIMERA". Hermeus. Retrieved 2023-03-10.
- ↑ "Turbofan and Turbojet Engines Database Handbook" (PDF). ptabdata. Retrieved 31 July 2023.
- ↑ Engine Data Tables Springer
- ↑ Roskam, Jan (1985). Airplane Design - Jan Roskam - Google Knjige. ISBN 9781884885563.
- ↑ "Taiwan Plans Re-engineering J85 Turbojet Engines for Long-range Missiles". 3 January 2019.
- Gunston, Bill (2006). World Encyclopedia of Aero Engines, 5th Edition. Phoenix Mill, Gloucestershire, England, UK: Sutton Publishing Limited. ISBN 0-7509-4479-X.
External links
Wikimedia Commons has media related to General Electric J85 .
- GE J85 product page
- J85 picture
- "G.E.'s Small Turbojet" a 1959 Flight article
