World's largest jet engine gets greener

The GE9X jet engine, the largest in the world, delivers 10% more fuel efficiency compared to General Electric’s (Fairfield, Conn.) other environmentally-sensitive engine, the GE90-115B.
     
Improvements to the GE9X include blades, a 132-in. (diameter) front fan, and 16 high-strength carbon fiber composite fan blades, which is less than the 22 on the GE90-115B engine. Although there are fewer fan blades, GE9X’s front fan is larger than the GE90 predecessor. As for overall efficiency, the new blades increase fan tip speed, reduce the amount of fuel burned, and raise the efficiency of the low pressure turbine.

Ceramic matrix composites (CMC) are essential in the GE9X’s design. For example, the lightweight fan case is made from CMC, which will lower the engine’s weight by 350 lb. Other CMC parts inside the engine include the combustor and turbine, which withstand temperatures as high as 2,400° F. This lets the engine burn less fuel than the GE90.

The first GE9X engine will be tested in 2016, with flight trials expected to take place on GE’s flying test bed in 2017. Engine certification is scheduled for 2018. Boeing’s next-generation 777X aircraft should carry the GE9X.