A revolutionary 'open architecture'

The open fan architecture is a key component of aero-engine maker CFM International's "Revolutionary Innovation for Sustainable Engines" (RISE) technology development program which aims to demonstrate and mature a range of new technologies for future engines that could enter service by the mid-2030s.

In June 2021, GE Aviation and Safran (who are 50:50 partners in CFM) launched a technology development program targeting more than 20 per cent lower fuel consumption and CO2 emissions compared to today's engines. The CFM RISE (Revolutionary Innovation for Sustainable Engines) program will demonstrate and mature a range of new, disruptive technologies for future engines that could enter service by the mid-2030s.

In the same month, the companies also signed an agreement extending the CFM International 50/50 partnership to the year 2050, declaring their intent to lead the way for more sustainable aviation in line with the industry's commitment to halve CO2 emissions by 2050.

Technologies matured as part of the RISE Program will serve as the foundation for the next-generation CFM engine that could be available by the mid-2030s. In addition to the lower fuel consumption goal, the team will work on ensuring 100% compatibility with alternative energy sources such as Sustainable Aviation Fuels and hydrogen.

Now that development has moved one step ahead with the announcement at Farnborough that open fan technology will also be the focus of a major Airbus flight demonstration campaign to be performed in collaboration with CFM in the second half of this decade. The joint demonstration program will use shared flight test assets. Provisionally the plan is for CFM to perform engine ground tests, along with flight test validation at GE Aviation's Flight Test Operations centre in Victorville, California.

Central to the program is state-of-the-art propulsive efficiency for the engine, including developing an open fan architecture. This is a key enabler to achieving significantly improved fuel efficiency while delivering the same speed and cabin experience as current single-aisle aircraft. The program will also use the hybrid-electric capability to optimize engine efficiency while enabling the electrification of many aircraft systems.