GE Aviation designed and built the world’s largest testing bell-mouth inlet duct as part of its ongoing development of the new GE9X engine. Testing of the GE9X is due to start this spring, keeping the high-bypass turbofan engine on track to power the new Boeing 777X when that new long-range commercial jet debuts in 2020.
The GE9X engine will be a 100,000-lb thrust commercial aircraft engine with a 134-in. diameter composite fan case and 16 carbon-fiber composite fan blades. It will have 27:1 pressure-ratio 11-stage high-pressure compressor; a third-generation TAPS III combustor, for high efficiency and low emissions; and CMC material in the combustor and turbine.
In February, GE Aviation reported that final assembly is underway on the first full engine, with the testing process to follow. Almost 700 GE9X engines have been ordered by aircraft OEMs. The new engine design was designed by GE Aviation, with development partners that include IHI Corporation, Snecma and Techspace Aero (Safran), and MTU Aero Engines AG.
A bell-mouth inlet duct is a specially constructed channel used to direct air into the inlet of a gas turbine engine, for testing. Bell-mouth inlets are installed on engines being calibrated in a ground test stand, to guide air into the inlet guide vanes of the compressor.
The GE9X will be the world’s largest engine, as GE Aviation noted, six inches larger than the current GE90 engine model. To test it, it reportedly invested about $10 million at the Peebles (Ohio) Testing Operation, including the design and fabrication of the 18-ft-diameter, 12-ft-high, fiberglass testing bell-mouth inlet duct.
“The bell-mouth inlet for the GE9X engine is the biggest GE has ever used and was built to fit in front of the GE9X’s large fan,” stated Phil Dietz, GE9X program control board chair. “The inlet is a one-piece structure that conditions the air entering the engine’s fan and enables accurate airflow measurement during engine ground testing.”
A fourth fuel tank also was installed at the testing center.
“The new tank will provide the necessary fuel supply for GE9X certification testing as well as the increase in production testing of wide-body engines like the GEnx and GE90,” according to Brian DeBruin, plant manager at GE Aviation’s Peebles Test Operation. “The GE9X’s 27:1 compressor ratio, the highest pressure ratio of any commercial engine in service, led us to make changes to the pressure system,” said DeBruin. “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.”