For the next generation 777, engineers at General Electric are working behind the scenes on the world’s largest jet engine—the GE 9X. The Boeing 777, which happens to be the world’s largest twinjet, seats up to 400 passengers and has a flying range of 9,500 nautical miles. It takes tremendous thrust to lift 775,000 lbs. off the ground and fly it half way around the world. That's significant because the fan diameter is 11 feet and it turns at 2,500 rpms when cruising.
While these specs are incredible to ponder, the real innovation is occurring in the manufacturing processes and advanced materials. The new engine’s fuel nozzles are production 3D printed. The sixteen fan blades are of fourth generation carbon fiber, reducing fan weight by 15%.
The hotter an engine can run, the more efficiently it produces thrust. GE engineers developed ultra-heat resistant parts called ceramic-matrix components (CMCs) which can withstand temperatures up to 2400 degrees Fahrenheit. (Our high heat casters peak out at 800° F.) These CMC components must survive inside the combustor and the turbine where the powerful thrust is generated. Engine geeks will appreciate the GE 9X’s compression ratio of 27: 1 vs the highest commercial automotive engine at 14:1 (and most are between 10:1 and 12:1.)
Check out the embedded link showing the first test of this engine. And note the size of the concrete blocks that support the structure holding the engine during testing. Each generation of engine requires more reinforcement of this test stand.