A group of aerospace technology companies —
GKN Aerospace, together with
MTU Aero Engines AG (MTU),
Pratt & Whitney,
Collins Aerospace,
Airbus, and others — have announced the formation of a collaborative consortium to develop hybrid-electric and water-enhanced turbofan technology for future aircraft propulsion systems.
They are being supported by the European Union Clean Aviation Joint Undertaking (Clean Aviation) and aim to demonstrate the potential of these technologies to improve fuel efficiency and reduce aircraft CO
2 emissions by up to 25% compared to today’s propulsion systems for short- and medium-range aircraft. The consortium is coordinated by MTU.
The ‘Sustainable water-injecting turbofan comprising hybrid-electrics’ (SWITCH) project is focused on developing a novel propulsion concept built from two ‘revolutionary and synergetic’ technologies: ‘water-enhanced turbofan’ (WET); and hybrid-electric propulsion. By combining these technologies with Pratt & Whitney’s GTF engine architecture, the SWITCH concept aims to significantly enhance efficiency and substantially reduce emissions throughout the full operating envelope of an aircraft.
Technologies developed as part of SWITCH will be fully compatible with cleaner alternative fuels — such as ‘sustainable aviation fuel’ (SAF) — and will be evaluated for future use with hydrogen.
Henrik Runnemalm, GKN Aerospace’s vice president of the global technology centre in Sweden, said: “We are delighted to be collaborating in the SWITCH project and help address many exciting opportunities and challenges around thermal and electrical power management within a highly advanced propulsion system. We will leverage our unique hot-test rig in Trollhättan, Sweden, as well as our high-voltage electrical wiring developed by our GKN Fokker business in the Netherlands.”
Stefan Weber, MTU’s senior vice president, engineering and technology, said: “This highly impactful SWITCH consortium provides a unique opportunity to demonstrate the benefits of both WET and hybrid-electric propulsion technologies, not only independently, but as parts of a system. WET offers considerable potential to boost efficiency and reduce all emissions significantly for future aircraft propulsion systems, whether they are powered by conventional kerosene, SAF, or even hydrogen. Since the concept is gas turbine based, the WET concept fully leverages MTU’s expertise.
“The hybrid-electric GTF powertrain will enable even greater efficiency throughout all phases of flight by leveraging highly efficient megawatt class electric-motor-generators, power electronics, and batteries to optimise the performance of the fuel-burning gas turbine.
“The WET concept recovers water vapour from the engine exhaust and re-injects it into the combustion chamber to significantly improve fuel efficiency, reduce NOx emissions, and lessen contrail forming emissions. These technologies are designed to work together to deliver a step change reduction in emissions and energy use across the full operating system, while maintaining world-class reliability and operability.”