Volvo RM12
The Volvo RM12 is a low-bypass afterburning turbofan jet engine developed for the Saab JAS 39 Gripen fighter. A version of the General Electric F404, the RM12 was produced by Volvo Aero (now GKN Aerospace Engine Systems).
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Type | Turbofan |
National origin | Sweden/United States |
Manufacturer | Volvo Aero/GKN Aerospace General Electric |
First run | 1978 |
Major applications | Saab JAS 39 Gripen |
Developed from | General Electric F404 |
Design and development
Produced by Volvo Aero (now GKN Aerospace Engine Systems), the RM12 is a derivative of the General Electric F404-400. Changes from the standard F404 includes greater reliability for single-engine operations (including more stringent birdstrike protection), increased thrust, and the adoption of a full authority digital engine control (FADEC) system.[1][2] Several subsystems and components were also redesigned to reduce maintenance demands.[3] The air intakes of the engine were designed to minimize radar reflection from the compression fan, reducing the radar cross section of the aircraft overall.[2] The F404's analogue Engine Control Unit was replaced with the Digital Engine Control – jointly developed by Volvo and GE – which communicates with the cockpit through the digital data buses and, as redundancy, a hydromechanical back-up. Hydromechanical backup remains in the new Full Authority Digital Engine Control (FADEC) which Volvo began developing in 1996.[2] General Electric produces 50% of the engine. Elements such as the fan/compressor discs and case, compressor spool, hubs, seals, and afterburner are manufactured in Sweden, final assembly also taking place there.[2]
Applications
- JAS 39 Gripen
- IAI Nammer (as designed, not built)
Specifications (Volvo RM12)
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General characteristics
- Type: Afterburning turbofan
- Length: 4.04 m (159 in)
- Diameter: 0.889 m (35 in)
- Dry weight:
Components
- Compressor: Axial compressor with 3 fan and 7 compressor stages
- Combustors: annular
- Turbine: 1 low-pressure and 1 high-pressure stage
Performance
- Maximum thrust:
- Overall pressure ratio: 27.5:1
- Bypass ratio: 0.31:1
- Air mass flow: 68 kg/s
- Specific fuel consumption:
- Military thrust: 23.9 mg/(N s) (0.844 lb/(lbf hr))
- Full afterburner: 50.6 mg/(N s) (1.79 lb/(lbf hr))
- Thrust-to-weight ratio: 7.8
See also
Related development
Comparable engines
Related lists
References
- "Resonance problem hits Gripen Engine", Flight International, London, UK: Reed Business Information, 145 (4406): 15, 2–8 February 1994, ISSN 0015-3710, archived from the original on 16 December 2013, retrieved 16 December 2013.
- "Reaktionsmotor 12 - både vacker och stark" [Reaction Engine 12 – both beautiful and strong]. Tech World (in Swedish). SE: IDG. 8 January 2013.
- Volvo Aero (31 January 2008), "Gripen surpasses 100,000 flight hours – Volvo Aero's engine safest in the world", Volvo Financial Services Magyarország, Hungary, archived from the original on 10 January 2014, retrieved 12 January 2014.
External links
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