GE9X

Admin a écrit:Enfin mon avis n'est pas partagé par tout le monde

Mais le 777X sera lourd très lourd

Et l'A330NEO sera 4-5 t plus lourd que l'A330CEO

General Electric is gearing up for test runs of the first GE9X turbofan as components of the initial engine come together at its Evendale, Ohio, facility.
The engine is in development for Boeing’s 777X series and will be the largest turbofan ever produced in terms of physical dimensions. The overall fan diameter will measure 134 in.; the GE90-115B, currently the world’s biggest and most powerful engine, is 128 in. The GE9X will be equipped with only 16 fan blades, with each individual blade measuring more than 5 ft. in length.
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Final assembly follows successful tests of the high-pressure (HP) core that began in late 2015. The core, which includes the HP compressor, turbine and compressor, also demonstrated operability above the maximum “redline” speeds and achieved compressor pressure ratios over and above the engine’s 27:1 design target, according to the engine-maker. 
Key GE9X core design features include ceramic matrix composites (CMC) in the outer and inner liners of the low-emission, twin-annular preswirler (TAPS) combustor, as well as in the HP turbine’s first- and second-stage nozzles and first-stage shroud. The turbine also incorporates blades forged using a new manufacturing process that integrates an improved cooling circuit into the airfoil. The performance of the CMC components were verified in 2015 during tests of a modified GEnx-1B engine fitted with scaled GE9X components made from the low-weight, heat-resistant material.

The first round of GE9X certification tests are being conducted on the second GE9X production-configured powerplant built by GE. To prepare for the certification program, trials of the first full engine to test (FETT) GE9X engine commenced in March 2016, generating critical data on the full engine system and aerodynamic performance, mechanical verification, and aero thermal system validation. Testing of the FETT engine concluded earlier this year with a series of preliminary natural-icing tests at PTO, where the GE9X ran more than 50 test points, accumulating 168 hours and 162 cycles.

@GEAviation boss says GE9X intended for Boeing 777X flew for the first time this week via @dougcameron pic.twitter.com/cjFawWa6hH

— Robert Wall (@R_Wall) 14 mars 2018

Certification testing of the GE9X engine began in May 2017. Beyond flight testing, the engine recently  completed icing tests at GE Aviation’s facility in Winnipeg, Manitoba, Canada, and continues crosswind testing at the Peebles Test Operation in Ohio. Engine certification is expected in 2019.

The problem area is in the front of the engine’s 11-stage high-pressure compressor. “It’s a mechanical issue and nothing to do with the overall performance of the engine or the way it is set up,” said Ingling. “It is not an aerodynamic issue whatsoever.” Various solutions are being studied, although he declined to provide more detail until the fix is finalized. “We have the opportunity to put more durability into it, so we are in the midst of investigating that,” Ingling said.

lthough the fan case, which itself was given additional strengthening prior to the test, successfully contained the released blade, the case and strut by the turbine rear frame sustained damage. Changes included improvements to the turbine rear frame, revised under-cowl components and upgrades to the mounting system for the FADEC which, after the fan blade out test, had become loose.