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Design and development
The RB3011 is designed for the 180-300 passenger aircraft (e.g. Boeing 737 or Airbus A320). Rolls-Royce bought the Allison Engine Company in 1995, and has studied the Pratt & Whitney/Allison 578-DX propfan engine built in the 1980s.
The engine has two contra-rotating rotors (fans) on the outside of the engine nacelle, either at the front of the assembly ("tractor") or at the rear ("pusher"). Both pusher and tractor open rotor designs form part of the RR's long-term "15-50" vision, which is examining various architectures to tackle the 150 seat-aircraft market. Within 15-50 group -named for specific fuel consumption reductions of 15-50% compared with current generation engines- there are various options based on technology availability and maturity.
The open rotor design is known to have increased noise compared to normal turbofan engines, where noise is contained by the engine duct. The forward rotor is larger in diameter than the rear rotor, to avoid problems with eddies from the forward rotor tips. The rotors are powered by the engine shaft via an epicyclic gearbox. These[clarification needed] produce a large amount of heat.
It is hoped to reduce the fuel consumption of an aircraft, compared to those with normal turbofan engines, by up to 30%. This is main reason for choosing this design of engine. Certification is planned for 2017-8, with market entry with airlines by 2020.
- Comparable engines
- Related lists
- Aviation Week & Space Technology/24 November 2008