The engine also incorporates a composite fan case, similar to those developed for the GEnx engines in production for the 747-8 and 787, and is encapsulated within an integrated propulsion system from Nexcelle, a joint venture between GE and Safran. The configuration includes a low-drag, slim-line nacelle with outward opening cowl to reduce weight while allowing for easier maintenance access. Internally, the blisks and compressor blades are also coated in a smooth, impact-resistant surface finish to improve aerodynamic efficiency.
One of the most exotic features is the use of an oxide-oxide ceramic matrix composite (CMC) for the exhaust mixer, center body and core cowls. The lightweight, high-temperature-resistant material is well-suited for lightly loaded applications and is the first non-military GE engine with this technology, says principle engineer Bernie Renggli. “It’s two-thirds the weight of titanium, so we’re saving up to 45 pounds per engine, or 90 pounds per shipset.”