Rolls-Royce has started a new round of research into hydrogen propulsion technology. The latest phase of testing got underway on December 19 at the UK aircraft engine maker’s facility in Solihull and is focused on proving the performance of cryogenic liquid hydrogen pump systems.
The work is part of Rolls-Royce’s ongoing collaboration with low-cost carrier EasyJet. This is aimed at providing hydrogen powertrains for a new generation of narrowbody airliners from the mid-2030s onwards.
The test program is addressing the main engineering challenges associated with taking low-pressure liquid hydrogen, chilled to below minus 250-deg C (minus 418-deg F), and then pressurizing it so that it can be pumped into an aircraft engine to be combusted. According to Rolls-Royce, this is part of a process to confirm the safety of three key functions needed for hydrogen to be used as an aviation fuel, namely: fuel combustion, fuel delivery, and fuel systems integration with an engine. The trials in Solihull, which have also received funding from the UK government’s Aerospace Technology Institute, will continue into 2024 and will be focused on fuel delivery processes.
In September, Rolls-Royce used 100 percent hydrogen fuel in tests with a full annular combustor of a Pearl 700 engine developed for business jets. This test was conducted in partnership with Germany’s DLR aerospace research agency in Cologne.
In the longer term, EasyJet and the manufacturer are aiming to run a full gas hydrogen ground test on a Pearl turbofan, followed by ground tests with liquid hydrogen. In 2022, the partners set what they said was another world-first in running an AE2100 engine on 100 percent green hydrogen at the Boscombe Down test site in the UK.
“Hydrogen will be a key component in helping short-haul aviation to decarbonize its operations and so we welcome the continued progress in Rolls-Royce’s testing program,” said EasyJet’s director of sustainability, Jane Ashton. “We look forward to working with Rolls-Royce to develop these new technologies which have the potential to create a true step-change in the aviation industry.”
Meanwhile, Rolls-Royce has not made any public comment on prospects for selling its Electrical division, as announced by the group's CEO Tufan Erginbilgiç in late November. The continuation of hydrogen propulsion research and development would seem to suggest that Rolls-Royce is only withdrawing from the all-electric powertrain sector.
