Industry first for hydrogen-fuelled jet engine development

The effort to develop a hydrogen-fuelled jet engine is being led by Rolls-Royce in partnership with easyJet and assistance from Loughborough University’s National Centre for Combustion and Aerothermal Technology (NCCAT) and the German Aerospace Centre Deutsches Zentrum für Luft-und Raumfahrt (DLR) in Cologne where tests were carried out on a full annular combustor of a Pearl 700 engine. 

In a statement Johan Lundgren, CEO of easyJet, said: “We believe hydrogen is the future of short-haul aviation and the success of this test and progress being made demonstrates that this is becoming ever closer. We remain optimistic that it will play a critical role in helping us achieve the ambitious goals we set out in our net zero roadmap.”

Key to the achievement is the design of advanced fuel spray nozzles to control the combustion process. Significant engineering challenges had to be overcome as hydrogen burns hotter and more rapidly than kerosene; the nozzles control the flame position using a system that progressively mixes air with hydrogen to manage the fuel’s reactivity.

The individual nozzles were initially tested at intermediate pressure at Loughborough University’s test facilities and at DLR Cologne before the final full-pressure combustor tests took place.

These recent tests mean the combustion element of the hydrogen programme is now well understood, while work continues on systems to deliver the fuel to the engine and to integrate those systems with an engine.

In 2022, easyJet and Rolls-Royce set a world first by successfully running an AE2100 engine on green hydrogen at Boscombe Down, UK, and both companies are committed to a full ground test on a Pearl engine using liquid hydrogen.

Grazia Vittadini, chief technology officer at Rolls-Royce, said: “This is an incredible achievement in a short space of time. Controlling the combustion process is one of the key technology challenges the industry faces in making hydrogen a real aviation fuel of the future. We have achieved that, and it makes us eager to keep moving forward.”