July 19, 2004 -- FARNBOROUGH - Full-scale development is under way for General Electric Company's new GEnx jet engine, with several key technology-maturation tests underway this year.
In addition to validating key components and technologies, the GEnx development team this year is continuing to refine the engine design with the goal of launching a final design in early 2005.
The Boeing Company earlier this year selected the GEnx engine for its new 7E7 Dreamliner aircraft. Based on GE's fuel-efficient engine architecture pioneered by the GE90 engine, the GEnx engine is being designed to meet or exceed Boeing's aggressive performance targets for its new twin-engine 7E7.
The GEnx engine, the replacement for GE's highly successful CF6 engine family, will produce 55,000 to 70,000 pounds (245 to 311 kN) of thrust for the 7E7. The first full engine will go to test in 2006, followed by the first flight tests, with engine certification scheduled for 2007.
By year's end, the GEnx technology development program will be completed, clearing the way for final design, hardware releases, and initiation of the certification process. GE has already run compressor core development tests with better-than-expected results.
"While the GEnx is a new engine, it is based heavily on technologies GE has invested in over several years, including the GE90 and CFM* TECH56 programs," said Thomas Brisken, general manager of the GEnx engine programs. "Our focus is to mature those technologies through an aggressive schedule of validation testing over the next year."
The GEnx is being designed to bring a 15 percent improvement in specific fuel consumption over GE's highly successfully CF6-80C2 engine for wide-body aircraft.
The GEnx bypass ratio of almost 9.5 to 1, the highest for any GE engine ever developed, will be key to both fuel efficiency and noise reduction. The rundown of key GEnx technologies:
- Front fan. The 111-inch composite front fan and composite fan case provide 400 pounds in weight reduction. Based on the GE90 blade design, the GEnx front fan benefits from almost 20 years of GE research and development into composite fan blade technology. GE has the only composite fan blades in airline service, and they have exhibited remarkable durability on the GE90.
- Compressor. The 10-stage high-pressure compressor (HPC) is based on the GE90-94B and remains the highest-pressure-ratio compressor in the industry. Earlier this year, GE ran its development engine core #7, which validated and exceeded expectations in terms of compressor efficiency and operability. Engine core #8 will run in 2005 to further validate the GEnx compressor design.
- Combustor. The GEnx will incorporate a twin-annular, pre-swirler (TAPS) lean-burning design that allows for efficient fuel mixing before ignition, resulting in significantly lower NOx levels and better hot section life. TAPS technology was developed over several years through the TECH56 program, with more than 4,000 test cycles run.
- Turbine. A two-stage high-pressure turbine (HPT), with fewer airfoils than the GE90, is followed by a multi-stage, counter-rotating, low-pressure turbine (LPT). GE has been developing counter-rotating turbine systems since the 1980s, but this represents the first entry into an airline engine. The counter-rotating design will reduce swirl losses from the HPT and result in improved fuel burn, and fewer parts in both the HPT and LPT.
In addition to seven GEnx engines dedicated to the certification program, GE will dedicate two GEnx engines for long-term endurance testing as part of a multi-year engine maturation program. By aggressively accumulating engine cycles years ahead of any GEnx engine in revenue service, GE will better understand the engine's operating characteristics and better align repair development and work-scoping with the engine maintenance cycle life.
GE Transportation - Aircraft Engines, a part of General Electric Company (NYSE: GE), is one of the world's leading manufacturers of jet engines for civil and military aircraft.
* CFM International is a 50/50 joint company between GE and Snecma Moteurs