Rolls-Royce has officially started building the world’s largest aero-engine, UltraFan. Work on the first module is underway at the DemoWorks facility in Derby, UK, and the demonstrator engine, which has a fan diameter of 140 inches, will be completed by the end of the year.

Artist’s impression of the UltraFan demonstrator

The engine is the basis for a potential new family of UltraFan engines able to power both narrowbody and widebody aircraft and deliver a 25% fuel efficiency improvement compared with the first generation of Trent engines.

Gas turbines will continue to be the bedrock of long-haul aviation for many years, and UltraFan’s efficiency will help improve the economics of an industry transition to more sustainable fuels, which are likely to be more expensive in the short-term than traditional jet fuel. The first test run of the engine will be conducted on 100% Sustainable Aviation Fuel.

Significant investment has been made to develop the UltraFan demonstrator and associated technologies by Rolls-Royce and a variety of funding agencies, including the Aerospace Technology Institute and Innovate UK (United Kingdom), LuFo (Germany) and Clean Sky Joint Undertaking (European Union).

As engine build starts, other key parts are already coming together for delivery to Derby. Work is underway on UltraFan’s carbon titanium fan system in Bristol, UK, and its 50MW Power Gearbox, which is powerful enough to run 500 family cars, in Dahlewitz, Germany.

UltraFan is part of Rolls-Royce’s IntelligentEngine vision; for example, each fan blade has a digital twin which stores real-life test data, allowing engineers to predict in-service performance. When on test at Rolls-Royce’s new £90-million (US$125-million) Testbed 80 facility, data can be taken from more than 10,000 parameters, detecting the tiniest of vibrations at a rate of up to 200,000 samples per second.

Key engineering features of the engine include:

• A new, proven, Advance 3 core architecture, combined with ALECSys lean burn combustion system, to deliver maximum fuel burn efficiency and low emissions. Enhanced with further technologies and innovative high-temperature materials, UltraFan pushes the Advance3 core overall pressure ratio to more than 70:1 for a typical large engine application.

• Carbon titanium fan blades and a composite casing that reduce weight by up to 1,500 lb (680 kg) per aircraft.

• Advanced ceramic matrix composite (CMC) components that operate more effectively in high-pressure turbine temperatures.

• A geared design that delivers efficient power for the high-thrust, high-bypass ratio engines of the future.