Future Of Flight: These GE Engineers Are Finding Ways To Reduce Carbon Emissions

The transition to cleaner sources of energy is one place where GE is helping decarbonize the world and address climate change. Another area involves aviation. GE spent $1.8 billion in 2020 on aviation research and development, including new advanced materials and technologies that can help cut fuel consumption, emissions and even enable hybrid electric design, says John Slattery, president and CEO of GE Aviation. In June, for example, CFM International, a 50-50 joint company between GE Aviation and Safran Aircraft Engines, unveiled the CFM RISE Program (short for Revolutionary Innovation for Sustainable Engines), which aims to develop bold technologies such as open-fan designs and hybrid electric systems that could help improve fuel efficiency in new engines by more than 20% by the middle of the next decade. Take a look at some of the latest technologies GE engineers have been working on: Rising to the Challenge

Top image: Open rotor concept. Infographic credit: GE Reports.

How do you build the most advanced aircraft engines while cutting carbon emissions? GE Aviation and Safran Aircraft Engines have done it for nearly 50 years through CFM International. In June, the pair announced they are extending their partnership to 2050 and launching the Revolutionary Innovation for Sustainable Engines (RISE) Program to develop an engine that will use at least 20% less fuel and produce more than 20% fewer CO₂ emissions than the most efficient jet engines built today. If just 10% of the world’s single-aisle aircraft were replaced in the future by an open-fan engine like the one envisioned for the CFM RISE Program, it would reduce CO₂ emissions by some 8 million metric tons each year. That would be like taking 1.6 million vehicles off the road. “This technology development program demonstrates the commitment GE and Safran share for achieving ambitious goals for a more sustainable future,” says Travis Harper, the GE product manager on the CFM RISE Program. “I also spend a lot of time with airlines and lessors trying to understand their strategies for the renewal of their fleets, coupled with their strategies to be more sustainable, and how our future products can help address their needs both in the immediate term and after 2050,” Harper says. Another Big Leap

Image credit: IndiGo

The RISE Program is building on the success of another CFM undertaking: the LEAP engine. India’s IndiGo airline, one of the world’s fastest-growing, low-cost carriers, announced in May it will equip 310 new aircraft with the LEAP-1A engine from CFM International. The agreement, one of the largest in CFM’s history, includes 620 new installed engines and associated spare engines, as well as a multiyear service agreement. “This is a pivotal milestone that reflects our long-standing commitment to rapidly strengthen our network both domestically and internationally,” said IndiGo CEO Ronojoy Dutta. “This expansion will serve as a catalyst to boost India’s economic growth and the mobility of its people.” CFM started developing the LEAP engine nearly two decades ago. Using advanced materials and technologies, the engineers were able to lower fuel consumption by 15%, reduce CO₂ emissions and make it quieter than the engine’s predecessor, the CFM56. The LEAP engine has logged more than 10 million engine flight hours in five years of commercial service. IndiGo will use the LEAP-1A in its new fleet of Airbus A320neo, A321neo and A321XLR aircraft. Certificate Of Achievement

The GE9X engine and the aircraft it was designed for, the Boeing 777X, will be 20% more fuel-efficient than their predecessors. Last year, that powerfully efficient engine got one step closer to service when it was certified by the Federal Aviation Administration.

A couple of decades ago, engineers from GE Aviation canvassed customers to learn what they wanted to see in an ideal jet engine. The engineers turned up a wish list of about 300 items, with one wish firmly at the top: fuel efficiency. That’s no wonder. Fuel accounts for close to a fifth of an airline’s operating costs. Those engineers got to work — and came up with the GE9X engine, which is designed to be up to 10% more efficient than its predecessor. Efficiency isn’t the only thing this machine has going for it, though. It’s also the most powerful jet engine in existence. Last year, the Federal Aviation Administration certified the GE9X — meaning that GE can start manufacturing engines for commercial service. The milestone came after a testing process that was long and grueling, at least from the engine’s standpoint. Following a regulator-prescribed regimen, engineers subjected it to all manner of hardship. The engine is tough, but it’s also cutting-edge: The GE9X achieves its efficiency gains partly through the use of lightweight but heat-resistant ceramic matrix composites, as well as 3D-printed parts. And the engine is smart, incorporating big data and analytics to help airlines save time and money. GE Aviation’s GE9X general manager Karl Sheldon summed it up: “We’ve developed an aircraft-engine combination that I honestly think is going to be unbeatable in the marketplace.”

A row of upstream bars produces highly turbulent flow that gets accelerated through a high-pressure turbine blade row and interacts with the blade surface, causing significant temperature variations. Image credit: Richard Sandberg, University of Melbourne

How does a supercomputer earn its wings? Modeling complex turbulence to help engineers improve critical jet-engine turbines is a pretty good start. Researchers at GE Aviation and the University of Melbourne have been using supercomputers to study turbulent flows — the powerful, dynamic mixtures of hot gases that rush from an engine’s combustion chamber and through its high-pressure turbines to power the aircraft. These turbines are critical to jet engine propulsion, so even tiny improvements in their efficiency can mean big cost savings for the aviation industry. To map the complexities of the propulsive flow as accurately as possible, the team at Aviation solicited help from the most powerful computer in the country: the Summit supercomputer at the U.S. Department of Energy’s Oak Ridge National Laboratory. With Summit, the team is better equipped to model real engine conditions, studying how turbulent flows transfer heat close to the turbine blades. “Our flow speeds and everything else were similar to what you would really have inside of the engine,” says Sriram Shankaran, a consulting engineer at GE Aviation. Using direct numerical simulations, or DNS, the team captured the full range of turbulence scales in a single model. “These are as close to reality as you can get,” Shankaran says. Lofty Ambitions In terms of fuel efficiency, commercial aviation has come a long way: The amount of fuel used per passenger has dropped 80% since 1960. Still, those savings have been offset by the skyrocketing growth of passenger aviation in the same period, leading aircraft and engine designers to search for new ways to reduce aviation’s impact on the environment in the decades to come. “We need something fundamentally different to take the next leap,” said John Yagielski, senior principal engineer at GE’s Global Research Center in Niskayuna, New York. Yagielski and his colleagues are at work on something fundamentally different indeed: an electrically driven propulsion system powerful and light enough to keep aloft a 175,000-pound commercial airliner and its 175 passengers. That goal is being backed up by $4.8 million in new research grants from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) — and it will be no small feat. The challenge is figuring out how to convert a cleaner-burning biofuel into megawatts of electricity, and then how to turn that electrical energy into enough thrust to fly a Boeing 737-class jet. But that challenge is also an invitation for the GE engineers to reimagine what an aircraft engine looks like, drawing up new designs that might be more efficient for flight than the traditional model of engines beneath each wing. “It’s about proving the feasibility of a number of these technologies and convincing ARPA-E to invest in building a complete prototype and testing it,” Yagielski said. “This is for aircraft in the 2050s.” This article originally appeared on GE Reports.