Singapore Air Show

CFM Plans eCore3 Tests in 2012

 - February 14, 2012, 7:30 PM
CFM engine at the CFM International booth, Singapore Airshow 2012. Photo by David McIntosh.

In late 2012 CFM International plans to run the third development core, known as “eCore 3,” for the Leap engine it is developing for the Airbus A320neo, Boeing 737 MAX and Comac C919 airliners. On Tuesday, the General Electric-Snecma join venture also announced it is ramping up production, after having delivered 1,354 CFM56s last year.

The eCore 3 is now in the build-up process, CFM executive vice president Chaker Chahrour said during a briefing here at the show yesterday. The schedule calls for the first test to happen in December but so far the process has been ahead of schedule. Compared to the eCore 2, the eCore 3 has the same configuration–10 stages in the high-pressure (HP) compressor, a TAPS 2 combustor and two stages in the HP turbine.

The difference is in size, Chahrour said. “The sizes are closer to the final design–until eCore 2, we were trying to guess what the airframers’ requirements would be,” he explained. Still, a lot was learned with eCore 2 in terms of efficiencies and margins.

The first full Leap engine is to begin testing in the third quarter of 2013. By then, another way to test Leap components will be installing them on a GEnx engine (the type usually powers the Boeing 787 and 747-8). Four “endurance builds” are planned.

On the first one, in March, some HP turbine blades will be “scattered among GEnx blades” on the disk, Chahrour said, allowing CFM engineers to compare durability performances. The environment in the GEnx will even be a bit hotter than that of a Leap. Obviously, Leap blades are not optimized for the GEnx so engineers will not check for efficiency.

Also tested from March will be a shaped multi-hole combustor liner and ceramic-matrix composite (CMC) shrouds. In September, the second build will include HP compressor and combustor coatings as well as HP turbine airfoil cooling.

In February, a full set of Leap blades will replace the GEnx blades on the HP turbine. In June, the engine will be “heavily instrumented” to gather “detailed data.” All this will take place at GE’s Peebles, Ohio test facilities in the U.S.

One of the Leap’s features Chahrour insisted on is its “FOD-free core.” Thanks to the spinner and fan blade design no foreign object is allowed in the core. “This prevents foreign object damage and erosion in the core,” Chahrour pointed out. Fan blades, due to their size and construction (on the Leap this is 3D-woven composites), are less sensitive.

In production, CFM is planning about 1,400 engines deliveries this year, up from 1,354 in 2011. This is forecast to gradually increase to 1,600 in 2014. Depending on Airbus and Boeing production rates, some scenarios push the annual output up to 1,800 in 2018. The transition from the existing CFM56 to the Leap engines is expected to be completed by 2019.