Rolls-Royce schedules first run for next February
Rolls-Royce is aiming to begin assembly of the first Trent 1000 engines for the Boeing 787 in November after having recently completed final configuration definition of the powerplant.
The first engine test is now scheduled for 14 February 2006, with certification in mid-2007 and entry into service a year later. "We're in the design-make process, and getting into detailed design," says Trent 1000 chief engineer Andy Geer. "Long lead-time parts are gradually being released, for pieces such as the front fan case. The first combustor from Mitsubishi Heavy Industries [MHI] is going into rig tests, and the first forgings are coming through for the high-pressure [HP] turbine disc and the intermediate-pressure [IP] compressor drum," he adds.
The finally defined engine incorporates a forged titanium, lightweight and rigid fan case with advanced acoustic treatment at the front and rear fan-case liners. Highly raked fan-outlet guide vanes are set aft of the fan, which is made up of 20 wide-chord, swept hollow-titanium blades.
The inner annulus line of the hub has been pushed down to reduce the hub-to-tip ratio and increase the flow area without altering the outside diameter of the engine. This allows the flow area to be "almost the same as if the fan diameter was 114in [2.89m], rather than the official 112in diameter," says Geer. "You get the effect of a higher bypass ratio without the extra weight, and this way it still fits in a 747 for transport," he adds.
The eight-stage IP compressor is conventional but, for the first time on an R-R "big-fan" engine, incorporates a de-icing system in the core. Forty-four of the engine sector stators are pneumatically heated to prevent ice accumulation from freezing fog. "This is ahead of the rules, which are just catching up with what we've learned in service," says Geer.
Other features include a single-skin tiled combustor, which is more suited to the bleed-free requirements of the more-electric 787, a single-piece titanium intercase casting, and for the first time the use of forced-air-cooled IP turbine blades. Unlike previous Trent engines in which the HP spool drives the external gearbox, the IP spool is used in the Trent 1000 to suit the unusually high electrical generation needs of the 787.
GUY NORRIS/LOS ANGELES
Source: Flight International
