07 January 2005
07 January 2005
General Electric Company (GE) has initiated tests for its new GEnx engine that advance the use of composites in jet engines.
The GEnx is the only jet engine being developed with both the front fan case and fan blades made of composite materials - a breakthrough that will provide greater engine durability and dramatic weight reduction.
At GE Transportation's headquarters in Evendale, Ohio, the company ran a successful ""blade-out"" rig test using a composite fan case and composite blades representative of the GEnx configuration. In this test, a fan blade is released while the fan operates at full speed. The composite fan case maintained its structural integrity while containing the released blade.
""Simply put, the concept of a composite fan system worked, and worked well,"" said Tom Brisken, general manager of the GEnx program.
The GE90 represents GE's investment in the future of wide-body aircraft. Over the past two decades, GE's CF6 and CFM56* engines have been chosen to power more than 50 percent of all new aircraft ordered with a capacity of 100 passengers or more.
The Guinness Book of World Records recognized the engine as the ""World's Most Powerful Commercial Jet Engine"" in 2001 after it recorded an amazing 123,000 lbs. of steady-state thrust while undergoing initial ground testing. In late 2002, the engine shattered its original record by reaching 127,900 lbs. of thrust during required certification testing.
The Boeing Company selected the GEnx engine for its 7E7 Dreamliner aircraft. Airbus selected the GEnx engine to power its initial A350 aircraft. Based on the fuel-efficient GE90 engine, the GEnx is being designed to meet or exceed performance targets for both aircraft.
The GEnx team is refining the engine design, and maturing key technologies, in order to commit a final design in early 2005. The first full engine will go to test in 2006, with engine certification scheduled for 2007.
Carbon fibre and epoxy resin composite materials are a key to GEnx performance. The composite fan case will reduce engine weight by 350 pounds, or 700 pounds in a two-engine aircraft. Overall weight reduction is more than 800 pounds for the aircraft because composite materials also allow for weight avoidance in the engine installation. The weight reduction translates directly into fuel burn savings, increase payload, and greater aircraft range.
GE introduced the first composite fan blades in jet travel in 1995 with the GE90 engine on the Boeing 777. During nine years in airline service, the GE90 composite fan blade has proven to be extraordinarily reliable, with no special inspections or field actions ever required.
The most recent GE90 derivative, the GE90-115B for the 777-300ER and 777-200LR, introduced composite blades that were designed using three-dimensional aero technology. (The uniquely shaped blade is on display at the Museum of Modern Art in New York City.)
GEnx composite fan blades will be produced using the same fibres, resin, and manufacturing processes as the GE90 fan blade.
The GEnx fibre-braided composite fan case, to be the first in commercial service, results from more than 20 years of GE research and development, including testing on a NASA demonstrator engine. In addition to weight savings, the fan case's composite properties create a tough, hard structure that eliminates the potential for corrosion.
Before GEnx engine certification testing goes into full swing in 2006, GE will have run four rig tests on the composite fan system. In addition to the reduced scale ""proof of concept"" test recently conducted, GE will run a second reduced scale rig test in April 2005. These tests are designed to mature the technology.
In late 2005 and in 2006, GE will run two additional rig tests using a full-scale fan case and blades. These tests will evaluate the GEnx fan configuration.
GEnx is the next-generation of the engine technology to succeed GE's CF6 series, the best-selling engine family for widebody aircraft. The GEnx engine will produce 55,000 to more than 70,000 pounds (245 to 311 kN) of thrust for the 7E7. For the A350, the GEnx engine will produce 72,000 pounds (320kN) of thrust.