Story ID: 437
Rolls-Royce Runs Pearl 700 on Hydrogen Fuel
By: Charles Alcock
Caption: The aero engines group has also tested a new small gas turbine intended for hybrid-electric powertrains
Word Count: 418
Rolls-Royce and its partners recently ran a Pearl 700—the turbofan engine that powers the Gulfstream G700—on 100 percent hydrogen fuel as part of longer-term work to develop a hydrogen combustion engine for narrowbody airliners by the mid-2030s. Working with the UK’s Loughborough University and German aerospace research agency DLR, the aero engines group said tests on a full annular combustor proved that hydrogen can produce maximum takeoff thrust.According to Rolls-Royce, the breakthrough is based on new fuel spray nozzles that control the combustion process. “This involved overcoming significant engineering challenges as hydrogen burns far hotter and more rapidly than kerosene,” the company explained. “The new nozzles were able to control the flame position using a system that progressively mixes air with the hydrogen to maximize the fuel’s reactivity.”The individual nozzles were initially tested at intermediate pressure at Loughborough University’s new test facilities at the National Centre for Combustion and Aerothermal Technology. Then the hardware was tested at the DLR’s facility in Cologne, Germany, where the final full-pressure combustor evaluation was conducted using rigs at the agency’s Institute for Propulsion Technology.“This is an incredible achievement in a short space of time,” said Rolls-Royce chief technology officer Grazia Vittadini. “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 it easier to move forward.”Rolls-Royce is working with low-cost carrier EasyJet to develop a larger hydrogen propulsion system. Last year, the company successfully ran an AE2100 turbofan engine on green hydrogen at the Boscombe Down research facility in southern England. Airbus is also involved in the newly formed UK Hydrogen Alliance.The next step for the partners is to incorporate the learnings from both sets of tests to develop a full gas hydrogen ground test on a Pearl engine. Beyond that, they intend to conduct ground tests on the same type of turbofan using liquid hydrogen.At the Paris Air Show in June, French startup Beyond Aero unveiled plans to develop a hydrogen-powered midsize business jet. The company aims to bring the aircraft to market by around 2030 and with a target range of 800 nm. The Toulouse-based company has already built and tested an 85-kW subscale technology demonstrator of the hydrogen fuel cell-based powertrain it intends to develop in-house. It said the 1-MW class propulsion system will include a pair of ducted fans at the rear of the fuselage., plain_text