On 29th November, a group of technology companies announced the formation of a collaborative consortium to develop hybrid electric and water-enhanced turbofan technology for future aircraft propulsion systems, supported by the European Union Clean Aviation Joint Undertaking (Clean Aviation)
MTU Aero Engines AG, (MTU) Pratt & Whitney, Collins Aerospace (Collins), GKN Aerospace, Airbus, and many others aim to demonstrate the potential of technologies like these to improve fuel efficiency and reduce aircraft CO2 emissions for short and medium-range aircraft. The consortium is coordinated by MTU.
The Sustainable Water Injecting Turbofan Comprising Hybrid Electric (SWITCH) project is focused on developing a novel propulsion concept built from two revolutionary and synergetic technologies like Water Enhanced Turbofan (WET), and hybrid-electric propulsion. By combining these technologies with Pratt & Whitney’s GTF engine architecture.
SWITCH aims to significantly enhance efficiency and substantially reduce emissions across a full operating envelope of an aircraft. Technologies developed as part of SWITCH will be fully compatible with cleaner alternative fuels like Sustainable Aviation Fuel (SAF) and will be evaluated for future use with hydrogen.
Words of Expert
Dr. Stefan Weber, Senior Vice President, Engineering and Technology at MTU states, “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,”
Mr. Weber further adds on the benefits of WET saying, “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.”
Geoff Hunt, Senior Vice President, Engineering and Technology, at Pratt & Whitney mentions, “This project will enable us to advance several key technologies on our roadmap to further extend the efficiency of the GTF engine architecture.” Furthermore, he adds, “Given the challenge of reducing the environmental impact of aviation, cross-industry collaboration and public-private partnerships like Clean Aviation will play a vital role in delivering the technology breakthroughs needed to make net zero emissions aviation a reality.”
The WET concept recovers water vapor from exhaust fumes and re-injects it into the combustion process, improving fuel efficiency, lessening NOx emissions, and lowering contrail forming emissions. These ground-breaking technologies are intended to work together to deliver a significant reduction in emissions and energy consumption across the entire operating system while maintaining world-class reliability and operability.
Henrik Runnemalm, Vice President, Global Technology Center, Sweden, at GKN Aerospace, with zeal states, “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.” He added, “We will leverage our unique hot test rig in Trollhattan, Sweden, as well as our high voltage electrical wiring developed by our GKN Fokker business in the Netherlands.”
SWITCH Phase 1 funding is currently extended until 2025 and will include testing of a hybrid-electric GTF engine, WET technology and subsystem laboratory testing, and design activity centered on an integrated hybrid-electric and WET cycle propulsion system. Further phases of ground testing and flight tests are expected to follow if these key technologies and component designs are successfully tested.
Clean Aviation is a European Union-funded public-private partnership between the European Commission, the aerospace industry, and research institutes dedicated to advancing transformational aircraft technologies that will help aviation achieve net zero emissions by 2050. The project will be funded by UK Research and Innovation and will leverage collaboration between multiple aerospace companies, universities, and research organizations from 11 European and American countries.