SILOET 2: Project 3: Lightweight Fan System Design and Operation

The overall weight of a modern high bypass ratio large thrust engine, such as the Rolls-Royce Trent family is dominated by the weight of the fan system. Rolls-Royce is developing a composite fan system for deployment in future civil gas turbine engines, with the primary aim to deliver a significant weight saving. This enables substantial improvements in specific fuel consumption (sfc), thereby contributing to reduced emissions and achievement of the ACARE targets.
Improving the propulsive efficiency requires ultra-high engine bypass through design of the fan system, which means increasing fan diameter and potentially weight. With the introduction of a composite fan system an overall weight saving of >300 kg is possible, which equates to a 0.2% sfc reduction.
This was a collaboration between Rolls-Royce, GKN Aerospace and University of Bristol. This project developed future design and modelling capability and developed key capabilities for the overall fan system, ensuring its operation is robust and reliable. This included developing a robust liner system that protects the casing and allows the overall structure to be as lightweight as possible. The project also developed robust tip-rubbing capability for the blade tip; development of fire-proofing the composite casing structures; and development of Non Destructive Testing (NDT) capabilities to inspect the containment case and liner.
This project is an enabler for the next generation of aero gas turbines and offers enhanced product competitiveness through reduced engine weight, leading to reduced fuel burn and hence lower environmental emissions. The project has significantly grown the capability of Rolls-Royce in the domain of composite technology. A Composite Technology Hub has been established in Bristol; the advanced manufacturing centre will be at the forefront of developing the next generation of fan blades and fan cases.