General Electric · Case study
General Electric GEnx
The GE90's technology distilled into a lighter, cleaner engine for the 787 and 747-8. The GEnx carried composites further, added a low-emissions combustor, and dropped engine bleed air entirely on the Dreamliner.
Architecture
The GEnx is a two-spool high-bypass turbofan that takes the GE90's composite fan blades and goes a step further, making the fan case from composite as well to save weight. The fan blade count is reduced relative to earlier large fans, easing manufacture and maintenance.
Its combustor is the Twin-Annular Pre-Swirl (TAPS) design, which mixes fuel and air more thoroughly to cut oxides of nitrogen at high pressure-ratio conditions. On the 787 the engine runs a 'bleedless' architecture: cabin air comes from electric compressors rather than engine bleed, so the core is optimised without that off-take.
The cycle
A high bypass ratio and a high overall pressure ratio — among the highest in service on the 787 variant — combine for a marked fuel-burn improvement over the previous widebody generation, with lower noise and emissions to match.
Engineering significance
The GEnx made all-composite fan modules and bleedless operation routine on a high-volume widebody, and became one of the two engine choices on the 787 while powering the final passenger 747. It is the bridge between the record-setting GE90 and the high-volume LEAP.
Applications
Boeing 787 Dreamliner · 747-8
Explore a representative turbofan cycle for this engine class in the interactive console.
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