Rolls-Royce has revealed how it will increase the thrust of the baseline engine it is developing for the Airbus A350 by 13,000lbs 000 pounds to meet the take-off and climb requirements of the heavier, longer-range A350-1000.
The new Trent XWB version will produce 97,000 pounds lb at take-off, making it the most powerful production engine R-R has ever built, – and that Airbus has ever used.
According to Chris Cholerton , Trent XWB program director, Chris Cholerton the upgrade is “optimised optimized for commonality” with the 75,000-lb - to 84,000lbs 000-pound-thrust baseline engines powering the smaller A350-800 and -900. “This is a low-risk program, which will give Airbus the 400n.m-nm extra range and 4.5 metric tontonne extra payload they [Airbus] asked for,” he told AIN.
The decision to develop the higher thrust engine was made easier, said Cholerton, because of the baseline Trent XWB test program. “We’ve been very pleased with specific fuel burn figures, which have come out better than target and there are better efficiency and surge margins in the intermediate and high-pressure compressors.”
The figures were so good that R-R was able to trade the margin for fuel burn, he added, “and we’ve seen opportunities for further improvements.”
The extra thrust of the -1000 engine comes from a 6- percent increase in fan flow, coupled with aerodynamic improvements to the core. The fan has the same 180-inchin. diameter as for the baseline engine, but is driven at a higher speed.
“Keeping the fan the same size meant we could have a common nacelle,” said Cholerton. “It is not a compromise. The fan is the optimum size for the aircraft,” he added.
Despite the extra thrust, specific fuel burn will be the same as for the baseline engine’s, thanks to technology drawn from several R-R demonstrator programs, said Cholerton. A “next next-generation” material is being used for the single-crystal high-pressure turbine (HPT) blades, and shroudless HPT blades have been introduced to reduce stress at the higher temperatures of the engine. A lot of work has also been done to reduce tip clearances and improve airflow. Whole-engine X-Ray ray technology has also allowed engine functioning to be studied during running, leading to several minor improvements.
The agreement with Airbus to develop the upgraded engine was signed at the show on Tuesday by R-R’sRolls-Royce CEO John Rishton and Airbus CEO Tom Enders, further cementing R-R’s sole- source position on the A350-1000.
“The Trent XWB already had the potential for high production volume,” said Cholerton., “Nnow the certainty of high volume has increased.” He added that the production of Trent engines would double over the next five years, to one engine per day. “We’re working hard on making sure we have the production capacity in place in factories round the world,” said Chorlerton said.
Final assembly will take place in R-R’s Derby base but and also its new Seletar facility, in Singapore, due to open in mid-2012.
Separately, Qantas has agreed to pay Rolls-Royce $96 million in compensation,following the mid-air failure of a Trent 900 engine on one of its A380s on 4 September 20104 last year. The airline grounded all six of its aircraft for 23 days after the event.
Also yesterday, Japan’s aviation authorities granted certification to the Trent 1000 engine that powers the Boeing 787. The country’s ANA airline is launch customer for the widebody. o