Ultrafan Rolls-Royce’s jet engine of the future

A turbine capable of burning sustainable aviation fuel (SAF) has been tested by Rolls-Royce as part of the biggest overhaul of the British company’s engine designs for more than 50 years. The giant Ultrafan demonstrator, which has a diameter of almost 12 feet, is the basis for a new generation of engines that Rolls hopes will eventually cut fuel consumption by at least 10pc. It is also capable of running on 100pc SAF, which airlines want to adopt as part of efforts to cut their carbon emissions. Simon Burr, engineering chief at Rolls-Royce, said: “If you look at today’s Trent engines, you can trace their lineage back to the RB211 [an engine developed in the late 1960s] over 50 years of evolution. This is a new core, geared architecture, with a very big fan.” A key factor behind Ultrafan’s improvements is the engine’s use of a “power gearbox” that allows the fan and turbine to run at different speeds, improving efficiency. This means it can create more propulsion using less energy. A new core also provides an improvement in thermal efficiency in the combustion chamber, meaning it can withstand higher temperatures. Combined, these two things lead to overall efficiency gains of about 10pc over today’s engines. Mr Burr added: “The reason we built a really big engine is because that’s the most challenging. If you can build a really big engine, with the power and all the kind of challenges that come with it, you can scale it. “It’s designed to be scaled, from very large, right down to the narrow body aircraft that are in service today.”