‘World first’ | Rolls-Royce and Easyjet tests show 100% hydrogen combustion can power aircraft take-off

Engineers have devised a sophisticated fuel spray nozzle system to manage the combustion of fast-burning hydrogen (H2) within aircraft engines. Recent tests, conducted in collaboration with Rolls-Royce and Easyjet, have demonstrated that it is feasible to combust 100% hydrogen in an aircraft engine, even when it's operating at maximum thrust, ensuring a safe take-off.

The trials were conducted on Rolls-Royce's Pearl 700 engine at the German Aerospace Centre Deutsches Zentrum für Luft-und Raumfahrt (DLR) in Cologne. The primary focus was to safely and efficiently combust hydrogen under conditions that mimic the maximum thrust required for take-off. This task is particularly challenging because hydrogen burns at higher temperatures and with greater speed than conventional kerosene, as noted by Rolls-Royce.

Researchers at DLR, in collaboration with Loughborough University in the UK, have pioneered advanced fuel spray nozzles. These nozzles are instrumental in controlling the position of the flame, and they have also introduced a novel system that gradually mixes air with the hydrogen to regulate the fuel's reactivity.

The results of these tests indicated that both operability and emissions aligned with anticipated outcomes, according to Rolls-Royce. Grazia Vittadini, the Chief Technology Officer at Rolls-Royce, described this achievement as remarkable, emphasizing that controlling the combustion process represents a critical technological hurdle in the aviation industry's quest to make hydrogen a viable aviation fuel for the future.

However, critics have raised concerns about the challenges associated with incorporating hydrogen into airline operations. These challenges include hydrogen's poor round-trip efficiency and the complexities related to storing and loading the fuel.

While no modern airline operator has yet conducted a flight test with a combustion engine running on 100% hydrogen, several have experimented with aircraft powered by hydrogen fuel cells. Rolls-Royce and Easyjet, however, have committed to developing a hydrogen-powered combustion engine suitable for a range of aircraft by the mid-2030s, putting them in direct competition with Airbus, which aims to introduce its first commercial-scale hydrogen-powered aircraft by 2035.

In the previous year, the partnership tested one of Rolls-Royce's AE2100 engines using a 100% green hydrogen blend at a UK government-owned airfield in Boscombe Down, underscoring their dedication to advancing hydrogen as a viable aviation fuel.