Aviation is at the forefront of hydrogen powerplant research as the industry continues on its quest for zero- and low-emissions flight. To learn more about these pathfinding technology trials, as well as the partnerships that are beginning to develop the supply chain for these engines, we sat down with Hervé Moran, Rolls-Royce’s chief of future platforms for advanced concepts and global chief hydrogen technology for aviation.
Overall, hydrogen for aviation is still at a research and development stage, with early propeller aircraft like ZeroAvia’s modified 19-seat Dornier 228 taking their first air tests. Hydrogen-powered jets remain at ground test milestones, with Rolls-Royce’s Pearl 15 business jet engine ground tests well advanced in planning mode.
“It is very early days at this stage,” Morvan tells us, noting that “new supply chains are forming around hydrogen to bring new and additional competences together, in particular around the handling of the fuel, investigating the technical viability of such powerplants at technology level, and in their demonstration form.”
Critical to this work is early partnership working, with dozens of players from across industry, academia and government involved in tests, including most recently an AE2100 military turboprop aircraft in conjunction with the UK Ministry of Defence at its Boscombe Down site.
Indeed, says Morvan, “As we have demonstrated with our partnership with easyJet that saw an AE2100 run at the end of 2022, companies are well under way in demonstrating that their products can operate in a safe and controllable manner on hydrogen and similar efforts are taking place with our Power Systems division’s reciprocating engines.”
Industry and government funding, including from easyJet and the UK’s Aerospace Technology Institute, is pushing forward new collaborative programmes. The UK is funding three new programmes involving Rolls-Royce, researching hydrogen gas turbines in conjunction with industry and universities:
- Hydrogen Engine System Technologies (HYEST): a GBP14.8m project to develop technologies and sub-system architecture for the combustor element of a liquid hydrogen gas turbine, in partnership with Cranfield, Loughborough and Swansea universities
- Liquid Hydrogen Gas Turbine (LH2GT): a GBP31.4m project to develop technologies for the delivery of a liquid hydrogen fuel system for a hydrogen gas turbine, working with Manufacturing Technology Centre, Cranfield & Oxford universities, Reaction Engines, University College London, Heathrow Airport, and easyJet
- Robustly Achievable Combustion of Hydrogen Engine Layout (RACHEL): a GBP36.6m project to develop key technologies and integrated powerplant architecture for a liquid hydrogen gas turbine, together with Imperial College, the National Composites Centre, Reaction Engines, the University of Bristol, Spirit, Causeway Aero and ITP UK
“It remains a challenge across the aviation sector to obtain hydrogen for test purposes, particularly in its ‘green’ form. This is an issue which also impacts the ramping up hydrogen fuel for future aircraft as well as the production of sustainable aviation fuel. Fuel handling is also a challenge — on board and beyond — together with fuel distribution to form airport networks,” Morvan says. “We are also exploring the opportunity of fuel cell power, and the challenges of power density and thermal management, with our Rolls-Royce Electrical and Power Systems businesses and announced collaboration work with Hyundai at Farnborough Airshow last summer.” [Read the Press Release]
Indeed, fuel cells rather than hydrogen look set to be strong contenders in the early days of hydrogen, and smaller aircraft — growing from the commuter 19-seater size to the sub-50-seater market or even 75-seater turboprops — seem likely to be early candidates for development and later industrialisation.
“During the second half of the decade we expect to see a number of hydrogen technology demonstrators both on the ground and in flight,” Morvan suggests. “Initially these are likely to be fuel cell powered, with hydrogen combustion following later.”
Author: John Walton
Published 20 July 2023
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