UK industrial technology group Rolls-Royce has announced that it has started manufacturing the world’s largest aeroengine fan blades. These are for its UltraFan demonstrator power plant, which will be unprecedentedly efficient and sustainable. A full set of UltraFan blades will have a diameter of 140 inches (355.6 cm, or 3.566 m). This is only slightly smaller than the diameter of the fuselage of single-aisle (or narrow-body) airliners. (The Boeing 737 has a fuselage width of 3.80 m, while the equivalent figure for the Airbus A320 is 3.95 m.)
“This is the decade of UltraFan and it’s exciting to enter the 2020s with the start of production of the demonstrator engine,” enthused Rolls-Royce Civil Aerospace president Chris Cholerton. “We have got all the building blocks in place – the design, the technologies, a brand-new test-bed – and now we are actually seeing the engine come together.”
UltraFan’s fan blades and fan case are all made from composite materials. On a twin-engined aircraft, this will reduce total weight by 700 kg. The new engine will also cut fuel burn by 25%, compared with the first generation of Rolls-Royce’s Trent engine family (which first entered service 25 years ago this month). It will also cut emissions by the same amount.
The new fan blades are made by building up hundreds of layers of carbon-fibre materials, which are prefilled with resin material. This resin has enhanced toughness. Each blade is then subjected to heat and pressure, and then finished off with a thin titanium leading edge, which provides “extreme protection” (in Rolls-Royce’s words) against erosion, bird strikes and other foreign objects.
The UltraFan includes other innovations as well. It is a geared design, which maximises efficiency in a high-thrust, high-bypass ratio engine. It has a new architecture for its engine core, which provides maximum fuel efficiency and ensures a low emissions level. It employs advanced ceramic matrix composites (which are heat-resistant components which provide more efficient operation in high-turbine temperatures).
Rolls-Royce has already tested composite fan blades extensively, on an advanced low-pressure system (ALPS) development engine. These tests included flight tests on the group’s flying test-bed. (ALPS is based on a Trent 1000 engine; the flying test-bed is a modified Boeing 747 Jumbo jet, based in the US.)
The new engine will start its ground tests next year. It will be scalable from a 25 000 lb (111 205.5 N) thrust to a 100 000 lb (about 444 822 N) thrust and should be commercially available in the late 2020s.
The UltraFan is a central element in Rolls-Royce’s “sustainability strategy”, which sees ongoing research into improving the performance of gas turbine engines, as well as developing electric propulsion for aircraft and cooperating with partners in industry to increase the use of sustainable aviation fuels.
UltraFan also forms part of the group’s IntelligentEngine concept, which combines its products and services with digital technology. Thus, the engine has been designed using the most up-to-date digital technology, which will also direct its production. Digital technology will also allow engineers to analyse millions of data points gathered during the testing of the new engine.
The UltraFan technology development programme is also being supported by the UK Aerospace Technology Institute, Innovate UK (Britain’s innovation agency), Germany’s Luftfahrt Forschung aerospace research programme (Rolls-Royce Deutschland employs more than 10 000 people) and the European Union’s Clean Sky 2 initiative.