Rolls-Royce, in collaboration with partners easyJet, Loughborough University, and the German Aerospace Centre Deutsches Zentrum für Luft-und Raumfahrt (DLR), has achieved a significant milestone in its hydrogen research project. The project aims to develop hydrogen combustion engine technology for aircraft, including narrow-body planes, by the mid-2030s.
Successful Combustion of Hydrogen as Aviation Fuel
Tests were conducted on a full annular combustor of a Pearl 700 engine at DLR in Cologne, where the engine ran on 100% hydrogen. This milestone demonstrates that hydrogen can be successfully combusted at conditions equivalent to maximum take-off thrust. Crucial to this achievement was the development of advanced fuel spray nozzles to control the combustion process. Hydrogen burns hotter and more rapidly than traditional aviation fuels, posing significant engineering challenges. The new nozzles were designed to control the flame position by progressively mixing air with the hydrogen to manage the fuel’s reactivity. Combustor operability and emissions were found to be in line with expectations.
Testing Process and Achievements
Individual nozzles were initially tested at intermediate pressure at Loughborough University’s upgraded facilities and at DLR Cologne. The final full-pressure combustor tests occurred at DLR Cologne. Last year, easyJet and Rolls-Royce achieved another world-first by running a modern aero engine, the AE2100, on green hydrogen in the UK.
Future Steps
With the combustion element of the hydrogen program now well understood, further work will focus on systems to deliver hydrogen to the engine and integrate these systems. The next stages of testing will involve a full gas hydrogen ground test on a Pearl engine, followed by a full ground test using liquid hydrogen. The ultimate goal is to take this technology from ground testing to flight.
Industry Recognition and Support
Grazia Vittadini, Chief Technology Officer at Rolls-Royce, expressed her gratitude to easyJet, Loughborough University, and DLR for their support in achieving this milestone. Johan Lundgren, CEO of easyJet, emphasized the importance of hydrogen in short-haul aviation and its alignment with their net-zero goals. Professor Dan Parsons of Loughborough University highlighted the significance of this advance towards net-zero aviation. Markus Fischer of DLR praised the successful technology journey and DLR’s contribution to the rapid development of hydrogen combustion technology.
Supporting Programs
Rolls-Royce’s hydrogen research project receives support from various programs, including the UK’s Aerospace Technology Institute HyEST program, Germany’s LUFO 6 WOTAN program, and the European Union’s Clean Aviation CAVENDISH program. Loughborough University and DLR are partners in these programs. easyJet has invested in the development of hydrogen combustion engine technology for narrow-body aircraft.