Development work for the Rise open-fan engine has shifted from the design phase to an extensive ground testing campaign as CFM International prepares to begin flying a technology demonstrator in the coming years.
CFM launched the Revolutionary Innovation for Sustainable Engines (RISE) program in 2021 to develop a successor to the ubiquitous Leap turbofan engine, which powers the Airbus A320neo, Boeing 737 Max, and Comac C919 airliners. It could support the next generation of single-aisle aircraft that airframers such as Boeing and Airbus aim to introduce in the 2030s.
Pierre Cottenceau, executive vice resident of engineering and R&T for CFM partner Safran Aircraft Engines, updated AIN on the project's many technical advances. “We have made significant progress in our testing plan, which confirms the benefits of the Open Fan propulsive system for the next generation of single-aisle aircraft," he explained. "We successfully completed key tests on fan acoustics, aerodynamics, and blade ingestion, and the high-speed, low-pressure turbine, while advancing hybrid electric tests for our suite of pioneering technologies."
The joint venture between GE Aerospace and Safran Aircraft Engineslooks to achieve a 20% reduction in fuel burn and carbon dioxide emissions compared with the most efficient jet engines available today—a goal that GE Aerospace vice president of engineering Mohamed Ali says he feels increasingly confident it will achieve, and possibly overshoot.
During a media briefing before the Farnborough International Airshow at GE Aerospace’s Cincinnati headquarters last month, Ali said his team recently received some promising results from wind tunnel tests. Safran conducted the tests earlier this year in collaboration with the Onera aerospace research agency at its wind tunnel facility in Modane, France.
To validate the open-fan engine performance and noise levels, GE Aerospace has used supercomputers to run simulations and comparing calculations with real-world test results. “When we compare them to supercomputing predictions, always with computational fluid dynamics there is a correction factor—they never match,” Ali explained. “We needed none because we are able to model it essentially at the molecular level.”
With the power to process trillions of calculations per second, supercomputers are shortening the product development cycle “and enabling us to get accurate results faster,” Ali said.
GE Aerospace has become one of the largest consumers of supercomputing capability in the world, and the company now uses about the same amount of computational power as prominent artificial intelligence platforms like OpenAI, according to Ali.
Supercomputers Play a Critical Role
Last year GE Aerospace became the first business to use the U.S. Department of Energy’s new Frontier supercomputer. Located at Oak Ridge National Laboratory in Tennessee, it is the fastest supercomputer in the world, carrying the capacity to process more than a quintillion (one million trillion, or 1018) calculations per second.
Noise testing of the open fan design began last year at an Airbus facility in Hamburg, Germany. Those tests “validated that we can achieve lower noise with an open fan than today's Leap [engines],” Ali said.
At the 2022 Farnborough show, CFM and Airbus announced plans to begin flight-testing the open-fan technology demonstrator on an A380-based testbed. Earlier that year, the two companies signed a separate agreement to collaborate on a hydrogen demonstration program.
Airbus and CFM plan to install a modified GE Passport turbofan combustion engine on an A380 testbed filled with liquid hydrogen tanks and fly it by the end of 2026. Separately, GE Aerospace works with NASA to modify a Passport engine with hybrid-electric propulsion technology.
After successfully demonstrating the hydrogen-combustion technology with Airbus, CFM intends to produce a hydrogen-powered variant of the Rise engine, which will initially be compatible with ordinary jet fuel and sustainable aviation fuel, or SAF.
This hydrogen demonstration also contributes to Airbus’s ZeroE program, which aims to introduce a hydrogen-powered airliner capable of carrying around 200 people up to 2,000 nm by 2035.
So far the CFM Rise team has conducted more than 100 tests to validate various aspects of its engine technology. Ali called the results measuring durability and the capability of the open fan “quite encouraging."
"So we actually are increasingly feeling confident about our ability to achieve 20% fuel burn improvement and really set the standards for what the future will be,” he concluded.