CFM RISE: Supercomputers Boost Promise For Design And Performance

Evendale

Tests of the high-pressure turbine design for the CFM RISE core have begun at GE’s Evendale facility using a F110 engine.

Credit: GE Aerospace

PARIS—CFM International joint-venture partner GE Aerospace is for the first time detailing the widespread use of supercomputing in the design, development and testing of its next-generation RISE engine. 

Initial test results are encouraging as the program aims for a 20% fuel burn reduction goal, GE reports.

“RISE (Revolutionary Innovation for Sustainable Engines) isn’t any more just on paper—it’s for real,” says Mohamed Ali, vice president and general manager of engineering for GE Aerospace. Commenting on the eve of the Paris Air Show, Ali says a U.S. Energy Department (DOE) supercomputer is one of several being used to analyze the engine design. Other advanced computing tests are also ongoing to assess various areas including the high-pressure turbine design, and—along with Airbus—modeling of the open fan noise and installation characteristics.

The tests with Airbus, conducted at the OEM's facility in Hamburg, Germany, indicates noise levels of the open fan will be lower than those of the Leap, Ali says. “So, these are very encouraging results. It keeps us saying we’ll keep moving with the program and it’s quite exciting for us to be working with all the airframers,” he adds.

In the U.S. CFM has been using a recently commissioned supercomputer called Frontier at the DOE’s Oak Ridge National Laboratory, Tennessee, to model performance and noise levels of the open fan design under study as part of the RISE engine program.

With the processing power of around 37,000 GPUs, GE says the DOE supercomputer can model the vastly complex unsteady flow characteristics of the open fan in fine detail and at full scale. The 13-ft.-dia. single-stage fan and stator design is a key element of the RISE configuration.

However, as the first open fan design of this type, scale and puller configuration, there are many unknowns about how the interaction between the rotating fan stage, static stator stage, nacelle and installation might impact the performance and noise levels. GE therefore worked with the laboratory to develop computational fluid dynamics software for Frontier which was able to simulate air movement of a full-scale open fan design.

Frontier, which is a Hewlett Packard Enterprise-made Cray EX supercomputer with more than 9,400 nodes, can analyze data at more than exascale speed, or over a quintillion calculations per second. Exascale computers are digital computers, roughly similar to earlier-generation supercomputers but with much more powerful hardware. By running full-scale fan flow simulations, GE says it has been able to identify interaction areas and make design changes where appropriate ahead of testing using full-scale hardware.

The RISE demonstrator will also include a high-power gear system and a new compact high-pressure (HP) core to boost thermodynamic efficiency. It will also include a recuperating system to preheat combustion air with waste heat from the exhaust. The demonstrator will also include a swath of advanced materials such as ceramic matrix composites in the hot section and resin-transfer molded composite fan blades.

Evaluations of the RISE compact core have included supercomputers to test the design of the HP turbine blades and nozzles. Tests of the first full high-speed low-pressure (LP) turbine have also begun at GE’s Evendale, Ohio, facility using an F110 military engine. The work, which began earlier this month, is focused on the aerodynamic performance of the blades as well as demonstrating the advanced cooling system of the new design.

Guy Norris

Guy is a Senior Editor for Aviation Week, covering technology and propulsion. He is based in Colorado Springs.