The carbon-fibre composite blades allowed GE’s aerospace engineers to design the GE90, still the world’s largest and most powerful jet engine.
GE is still the only company with composite fan blades in service. They work inside the GE90 and the GEnx engines that power many Dreamliners. The material allowed GE engineers to design blades that result in lighter and more efficient engines, allowing airlines to save fuel by shedding precious pounds.
Kray and his team are now working on a fourth generation of the blade for the GE9X, GE’s largest engine yet. It is designed exclusively for Boeing’s next-generation wide-body jet, the 777X.
GE has already received orders and commitments for 700 GE9x engines valued at $29 billion (list price) from several growing Middle Eastern airlines like Emirates, Qatar and Etihad, as well as Lufthansa, Cathay Pacific and All Nippon Airways
The team says the blades will feature several new components. Stiffer carbon fibres will be used, meaning the blades can be made longer and thinner. Their trailing edge will be made from a special structural glass fibre composite that can better absorb impact energy. “Carbon fibre is very stiff and not that flexible so that when something hits the blade, it creates a shockwave deep inside it,” Kray explained. “But the glass composite can deform better and deflect stress on the blade.”
GE will also replace the titanium leading edge that is currently used on GE90 and GEnx blades with steel.
Where the GE90 has 22 blades and the GEnx has 18, the GE9X will have just 16, even though it is the largest of the three engines with a fan diameter of 134 inches.Besides making the engine lighter, the fewer and thinner blades will also spin faster, giving greater overall engine performance.
Ceramic matrix composites (CMCs) are made from special silicon carbide ceramic fibers locked inside a ceramic matrix. MCs don’t need to be air-cooled and weigh one-third the weight of metal.
In March 2013, the GE9X was selected as the exclusive engine to power the 777X. GE subsequently updated the GE9X specifications to reflect growing concerns that the 777X would be underpowered. Design changes included an increase of thrust to 102,000 lbf (450 kN), and then up to 105,000 lbf (470 kN) with a new fan diameter of 134 in (340 cm), giving the new engine the largest fan GE has ever produced.
Preliminary estimates placed entry into service for the first 777X variants at around 2019.
SOURCES- GE, Boeing, Wikipedia, Youtube