Engineering news
Jet engine manufacturer GE Aviation has unveiled and tested its 3D printed GE9X engine, that will power the next generation Boeing 777X, at its facility in Peebles, Ohio.
The engine spans 11ft (3.35m), making it the biggest in the world. GE has received a $29 billion order for more than 700 GE9X engines from airlines including Emirates, Lufthansa, Etihad Airways, Qatar Airways and Cathay Pacific.
GE9X can generate 100,000lb of thrust although its predecessor, the GE90-115B, reached 127,500lb. The engine features 16 carbon fibre fan blades at the front of the device, that feed air into an 11-stage high-pressure compressor with a 27:1 pressure ratio, which boosts the engine’s efficiency, according to GE.
The fuel nozzles were created through additive manufacturing and are composed of lightweight and ultra heat-resistant materials called ceramic matrix composites (CMCs), which can handle temperatures up to 1,316°C. This allowed the engineers to design the nozzles to have a complex internal structure. CMC was also used in the combustor and turbine, enabling the engine to maintain high heat and with less fuel consumption and emissions.
GE Aviation spokesman Rick Kennedy said: “These tunnels and caves are a closely guarded secret. They determine how the fuel moves through the nozzle and sprays inside the combustion chamber. The hotter the engine runs, the more efficient it is."
GE Aviation has invested $10 million to prepare its Ohio test centre for the GE9X. Engineers enhanced the testing stand’s air systems with new materials that can withstand high temperatures and added reinforcements that will secure the engine. The company also invested in a fourth fuel tank to keep the engine well fed for the procedure, and a ‘bellmouth inlet duct,’ a white funnel attached to the front of the engine during testing, which measures 18ft in diameter and 12ft in length.
Brian DeBruin, plant manager for GE Aviation’s Peebles test operation, said: “We also upgraded our engine hoists and transporters to handle the GE9X and modified a wall in our prep building so the engine can be moved after final assembly to make its way to the test stand.”
GE Aviation started engine trials in March to verify aerodynamic, thermal and mechanical capabilities of the engine. This will continue for the next months before it commences tests on the second GE9X in 2017, with plans to release the engine for service by 2020.
The project was initiated four years ago when Boeing solicited GE to develop an engine to power its next generation 777X jet. GE has been testing individual components and systems for four years since, although this is the first time it has fired up the whole engine.
GE9X programme leader Chuck Jackson said: “Due to the significant amount of new technologies in the GE9X, we planned the testing programme differently. The early testing informed the design and manufacturing and allowed us to freeze the product definition and test the total engine as soon as possible.”