“Cell A20 is one of the most unique test cells in Evendale,” said Geo van der Merwe, Component Test manager for Test Systems Engineering at GE Aviation. “The facility requires 60,000 horsepower (hp) of electric motors from nearby buildings to drive compressors that provide large volumes of air at pressures up to 1,000 per square inch (psi) to simulate the pressure and temperature of the GE9X engine.”


Construction wrapped last year on the 20,000 square foot test cell, and the site immediately fired up, setting a record for pressure and temperature for a combustion test facility at 1,500ºF and 1,009 psi. With a 200-foot tall stainless steel exhaust stack, the test cell has three parallel test stands capable of single-cup and sector combustor testing.

“We used to have to wait until a combustor ran in an engine to get data on its performance at an engine’s pressure and temperature,” explained van der Merwe. “The A20 combustor test facility allows us to simulate these conditions and test a combustor design in its early development, gaining insights into its reliability, emissions and fuel burn capabilities.”

For the GE9X, the test cell’s unique pressure and temperature capabilities are critical to its technology maturation efforts.


“The GE9X engine will incorporate a high pressure compressor with a 27-to-1 pressure ratio, the highest pressure ratio of any commercial engine in aviation service,” said Bill Millhaem, general manager of the GE90/GE9X program at GE Aviation. “Being able to simulate these conditions on the single-cup and sector level allows us to get data on how GE9X combustor will perform at true operating conditions.”

The new test facility can perform three types of tests:

  • High Temperature and Pressure (HTP) to determine durability capabilities of a fuel nozzle at pressure and different temperatures,
  • Tunable Combustor Acoustics (TCA) to screen hardware based on the frequency (Hz) and amplitude of the combustor’s dynamics, and
  • Sector rig on a subset of a complete engine combustor with seven nozzles or cups to allow product validation of initial light-off, operability and emission levels.

“A typical test can take up to 16 hours from start to finish since we have to be extremely careful on the pace in which we heat up material to ensure it doesn’t negatively impact the test hardware and equipment,” said van der Merwe.

The GE9X TAPS (twin annular pre-mixing swirler) III combustor builds on the TAPS technology in the GEnx and CFM International’s LEAP* engines. The TAPS combustor pre-mixes air and fuel prior to combustion for a leaner burn and fewer emissions than conventional combustion systems. The GE9X design 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 through a leaner burn, which will enable the GE9X to have a 30 percent margin to ICAO CAEP/8 standards for NOx (oxides of nitrogen). The GE9X TAP III combustor will feature fuel nozzle tips manufactured using additive technology, along with a new combustor dome design and ceramic matric composites (CMC) inner and outer liners, which improve durability and require less cooling air to enhance the lean-burn combustion process.

Watch the A20 test cell come to life in warp speed!

*CFM International is a 50/50 joint venture between GE and Snecma (SAFRAN) of France