Rolls advances three new engines
Engine maker Rolls-Royce is preparing the technology needed for new two-shaft and three-shaft turbofan engines in the second half of this decade and an open-rotor design in the early 2020s.
“Our long-term strategy is to invest in technology and protect our options,” said Mark King, Rolls-Royce president of civil aerospace. “Two years ago we decided to make sure we were capable of whatever the manufacturers want.”
Since then the business jet market has endured a period of turmoil as a result of what King terms “image issues,” the 150-seat airliner market has been engulfed in debate over whether to re-engine existing models, and Boeing and Airbus have put future widebody plans on hold while they address current programs. So Rolls-Royce has concentrated on staying “match fit, ready to bring technology to market quickly whatever the type of engine required,” King said in a pre-Farnborough airshow briefing last week. Rolls-Royce doubled its order book over the last four years, from $30 billion in 2006 to $70.5 billion in 2009.
The company’s existing programs–the Trent 1000 for the Boeing 787, Trent XWB for the Airbus A350 and BR725 for the Gulfstream 650–help it maintain its “match fitness,” King said. The Trent 1000, for example, is “the epitome of a highly integrated system. [Within an intense two-year period,] all 18,000 parts have been reviewed and improved since the previous Trent model, there is new technology in every component and all are optimized for each other.”
Integration of engine and aircraft is also important, he said. The Trent 700, purpose-designed for the Airbus A330 and competing with two rivals, has a 54-percent overall market share, but its share of orders since 2006 is 75 percent. “That is because it is the only engine optimized for the aircraft,” he commented.
The Trent XWB, meanwhile, started testing June 10, as planned four years ago. “It is 16 percent more fuel-efficient than the baseline Trent 700,” King said. Compared with previous Trents the compressor will have twice the compression ratio with fewer airfoils and 40 percent fewer aerodynamic parts, which he called “an amazing leap forward.”
The BR725-powered G650, meanwhile, has already broken speed records, the engine is performing flawlessly and it should be in service in a year or so.
New Platform Every Year
A new Rolls-Royce-powered commercial or general aviation aircraft or variant has entered service every year since 2000, and that pattern is set to continue through 2015 with the 787-8 and -9, G650 and A350-900, -800 and -1000, plus the Robinson R66 helicopter. Beyond that, King said, “the commercial world wants a highly optimized new aircraft,” rather than a re-engined product.
Rolls-Royce itself is “more and more convinced that we will see a new aircraft, as that’s what the market wants.” Accordingly, it has focused its technology programs on two new families: the two-shaft Advance2, to be ready for service entry in 2016-17, and the three-shaft Advance3.
The Advance2 is aimed at providing a 15- to 20-percent reduction in fuel burn for a new 150-seat aircraft. Based on the E3E core that has been running in Germany for two years, it would also be adaptable to large and mid-size corporate aircraft and regional airliners using smaller fans. The Advance3, targeting a 2017 to 2018 service entry and with thrust ranging from 30,000 pounds all the way up to 100,000 pounds, could be used for either narrowbody or widebody aircraft.
Looking further ahead, the open-rotor program is the “only real game-changer,” King said. Seen as entering service in 2022 to 2025, it represents the only technology that could deliver 10 percent better fuel economy than an advanced turbofan, “and we believe it will be quieter than any engine flying today–not as quiet as an advanced turbofan could be in the same timescale, but still quieter than current engines.” A lot of integration will be needed before it enters service, “but we’ve looked for sources of noise that would say this isn’t a goer and we haven’t found any.”
To put the fuel efficiency figures in context, he said reducing the airlines’ current fuel burn by 15 percent would mean a reduction of 10 billion gallons, saving $22 billion and 60 million tons of carbon dioxide, the equivalent of taking all the cars off the UK’s roads.
Whether the Advance2 project would be realized through Rolls-Royce’s International Aero Engines (IAE) partnership with geared turbofan proponent Pratt & Whitney remains to be decided. King said, “We still like IAE. It is still an attractive route to market, but we will have to see how it develops.”
Either way, he is adamant that it should be married to a new aircraft. “Another concern with re-engining is whether it creates delay in new aircraft programs,” King explained. “All the research says it needs to be a new aircraft and we don’t want to delay it, so we’re firming up the technology to be ready to address what the market really wants.”