Rolls-Royce, a leading aircraft engine manufacturer, is set to conduct ground tests later this year on a modified Pearl 15 business jet engine that has been adapted to run on gaseous hydrogen, marking a significant step towards sustainable aviation fuel adoption.
Crucial Tests Completed
Rolls-Royce has completed several key system and component tests in preparation for the full engine trials, including:
- Hydrogen tests on a Pearl 700 engine’s annular combustor in 2022
- Work on fuel nozzles and actuation
- Ground runs of an AE 2100 turboprop engine using gaseous hydrogen in November 2022
Simon Burr, Rolls-Royce’s group director of engineering, confirms that the project is “on track” for the ground runs later this year.
Challenges and Dual-Use Technology
While hydrogen’s combustibility isn’t a concern, safely shutting down the engine after running on hydrogen poses a challenge. Nitrogen purging is a potential solution.
Burr notes that if liquid hydrogen becomes the preferred fuel, heat-exchanger technology will be the most challenging aspect. However, he emphasizes that half of the technology being developed for the hydrogen demonstrator also has applications in conventional gas turbines.
CAVENDISH Project and Future Flight Testing
Rolls-Royce’s German unit is leading the Clean Aviation-funded CAVENDISH project, which aims to develop technologies for running a modern turbine engine on liquid hydrogen. The project, running from January 2023 to December 2026, involves 19 members, including Dassault Aviation, Embraer, and Fokker Next Gen.
CAVENDISH will focus on system and powerplant aircraft integration, certification pathways, and obtaining flying permits. Flight testing could occur in Clean Aviation’s second phase, after 2026. Rolls-Royce believes the programme will deliver mature technology to support future airframe decisions and contribute to the next phase of Clean Aviation.