As Rolls-Royce focuses on development of the Trent XWB for the Airbus A350 and the next version of Trent 1000 TEN for the Boeing 787, the company has unveiled its strategic roadmap for a new generation of turbofans for 2020 and beyond.
The ambitious plan centers on an evolution of its successful three-shaft architecture but depends heavily on a broad swathe of scalable technology which will position Rolls for new applications in the widebody market as well as, potentially, future narrowbody designs.
The roadmap also sees the U.K. engine maker formally introducing composite fan blade, casing and geared turbofan technology for the first time, as well as keeping the door ajar for potential open rotor derivatives.
The first engine, dubbed the Advance, will be tested in initial demonstrator form in 2015 based on a re-cored XWB. Although no specific application has either been identified or announced, Rolls says the new engine could enter service from 2020 onwards. The Advance was the basis for the company’s bid for the Boeing 777X for which General Electric’s GE9X was ultimately selected after an engine competition in 2013. Advance is outlined with a bypass ratio in excess of 11:1 and an overall pressure ratio of more than 60:1 and will have a fuel burn level at least 20% better than the current Trent 700.
Advance also forms the basis for a more ambitious engine dubbed the UltraFan which Rolls first revealed in concept form in early 2012 as part of a NASA Environmentally Responsible Aviation study with Lockheed Martin. The engine could be ready for service from 2025 and is targeted at an improvement in fuel burn “at least” 25% better than the Trent 700. The UltraFan will incorporate a geared fan drive system that drives a variable pitch fan system and is outlined with a 15:1 bypass ratio and overall pressure ratio of 70:1.
The two designs address mega trends in the engine business which has seen a constant improvement in propulsive efficiency, mostly through increases in fan diameter and bypass ratio, as well as shrinking cores and improvements in thermal efficiency. “It would be so easy to get complacent, and there have been plenty of examples of people who took their eye off the ball. But we’re not going to do that,” says Simon Carlisle, executive vice president, head of strategy and future programs for Rolls-Royce’s large civil engine business.
“We have strong and capable competitors who we respect and we want to maintain our position in the large engine business. So we continue to invest in technology and last year we spent just over £1 billion in techology funding. We need to keep doing that because the demands from the industry keep getting stronger. We know fuel prices are going to stay high and will only continue to go in one direction so we’re investing to address that,” says Carlisle.