GE Aviation has developed a high-bypass turbofan engine exclusively for the Boeing 777X. It is 10% more fuel efficient than the GE90 and although it is the biggest jet engine, it is however not as powerful as its predecessor. The engines size allows it to be more efficient and less noisy compared to the GE90.
The core of a turbofan engine is surrounded by a fan. In a high-bypass engine, most of the incoming air goes through the fan blades, around the engine, where it’s velocity is increased then fired back out. So it “Bypasses” the engine. The rest of the air goes through the core engine where it is mixed with fuel, lit up then expelled through a nozzle. Therefore the higher the bypass ratio, the more fuel efficient the engine is. Even though this can be achieved by increasing the size of the engine inlet (resulting in longer blades), the weight of the engine should then be minimised without affecting its ability to handle increased temperatures. Basically, the engine needs to be constructed using huge, lightweight, heat resistant engine components.
To achieve this, GE designed an engine with a fan that is 3.35m in diameter, has 16 fourth generation carbon fibre fan blades (6 less than the GE90) with a fan case using composite materials. They made use of 3D printed components and, for heat resistance, they used ceramic matrix composite materials in the combustor and turbine. The engine can generate 100000 pounds of thrust and has a bypass ratio of 10:1.
Not only is the GE9x the biggest engine in the world, it is also the most fuel efficient engine GE has ever produced.
Images sourced from ge.com.