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Development of an optimized large scale engine CFRP annulus filler

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Tough on hail, light on emissions

The aerospace industry often relies on metallic parts for strength and performance. A novel cost-effective composite engine component with 40 % less weight than the current best will make a major contribution to greener air transport.

Industrial Technologies

Increasing attention to reduced weight for lower fuel consumption and fewer emissions has led to exploitation of advanced carbon fibre-reinforced plastics (CFRPs) in many aircraft structures. A large consortium initiated the EU-funded project 'Development of an optimized large scale engine CFRP annulus filler' (ORCA) to expand applications. The annulus filler smoothes air flow, forming the inner air-washed surface between adjacent fan blades. Current state of the art designs are metallic, anodised for corrosion resistance and coated to prevent erosion. The team has now demonstrated the feasibility of using CFRP composites in this critical rotor system component of modern jet engines. Scientists developed a production process using an improved preform concept with important innovation regarding integration of connection parts. Detailed solutions have been included in patent applications. Following several design iterations, researchers manufactured and tested an annulus filler on the advanced low-pressure system of the sustainable and green engine (SAGE) concept for the SAGE3 project. Objectives were met and exceeded, setting a new benchmark for cost-efficient production of high-quality CFRP parts. The ORCA filler reduced the weight by 40 % compared to the best existing design. This was achieved with equivalent levels of stability with regard to impact and fatigue at a competitive cost. Exploiting the possibility for further cost reductions will lead to a lighter and less expensive part. The part, which received the 2014 JEC Europe Innovation Award in the aeronautics category, has been displayed at exhibitions and resulted in application of three patents. It is scheduled for flight-testing in the third quarter of 2014. The ORCA annulus filler is expected to improve jet engine efficiency and reducing emissions at no extra cost. This should majorly contribute to the EU's CleanSky research initiative and to SAGE. Publications in high-impact journals will enhance the international position of the university partner. With planned transfer to serial production in 2015-2016, the project's technology will also have important impact on the industrial partner's competitive position.


Aerospace, metallic, composite, engine, carbon fibre-reinforced plastic, annulus filler, rotor, preform, patent, SAGE

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