November 21, 2014
GE9X’s new TAPS combustor to maintain its cool under fire
Component testing of the TAPS III (twin-annular pre-mixing swirler) combustor for the GE9X engine for the Boeing 777X is demonstrating promising results. The GE9X TAPS III combustor is a unique third-generation combustion system that pre-mixes air and fuel prior to combustion for leaner burn and fewer emissions than conventional combustion systems. The TAPS combustion was introduced on the GEnx engine for the Boeing 787 Dreamliner and the 747-8 aircraft and was enhanced for the TAPS II combustor in CFM International’s LEAP engine for narrowbody aircraft. To design the world-class, low-emissions combustor, GE engineers successfully matched the combustion system to the GE9X’s 27:1 pressure ratio, which is the highest pressure ratio of any GE engine. The GE9X team utilized new technologies and materials that require less cooling air while allowing more air into the mixer. The additional air in the mixer helps reduce emissions by creating a leaner burn, which will enable the GE9X to have a 30% margin to CAEP/8 standards for NOx. Component testing of the TAPS III combustor began in 2012. This September, a full annular rig combustor test successfully demonstrated the material capabilities of the CMC combustor liners, which will be the first continuous CMC combustor liners in a commercial jet engine. The liners were tested at dynamic loading levels well beyond what it will experience in service. Additional full annular rig testing, including GEnx- and GE9X-scale combustors, will be conducted during the next two years. The first demonstration core test is scheduled for 2015. The first engine will test in 2016 with flight-testing on GE’s flying testbed anticipated in 2017. Engine certification is scheduled for 2018. IHI Corporation, Snecma and Techspace Aero (Safran), and MTU Aero Engines AG are participants in the GE9X engine program.