New Composite Engine Nacelle Looks to Reduce Noise

The innovative carbon fibre intake acoustic liner is unique because it is composed of a single composite piece, without splices, which could lead to significantly reducing noise pollution normally produced by traditional intake liners.

UL researchers Dr Trevor Young and Dr Aidan Cloonan, Irish Centre for Composites Research (IComp) and the Materials and Surface Science Institute are collaborating on the major European research programme, “Clean Sky Sustainable and Green Engines” (SAGE) dedicated to demonstrating new engine technologies for a range of future civil aerospace applications.

The European Commission’s Clean Sky research programme aims to “green” the aviation sector in line with Advisory Council for Aeronautics Research in Europe targets, that require the industry to cut carbon dioxide emissions by 50%, nitrogen oxide emissions by 80% and external noise by 50%.

In a significant milestone for the SAGE programme, Bombardier Belfast has designed and manufactured a large one-piece composite engine nacelle component, namely a carbon fibre composite intake acoustic liner, which encases and attenuates the noise of large turbofan aircraft engines.

Dr. Trevor Young, Materials and Surface Science Institute MSSI explains

The manufacture of acoustic liners from carbon fibre composites material presents a host of new challenges. New technologies for the drilling of thousands of small holes had to be developed. It was also important to develop an understanding of how the material would behave during a lifetime of service. To this end accelerated erosion and weathering testing is critical.

The full-scale intake liner, assembled to a one-piece lipskin, was formally handed over to Rolls-Royce to support its composite fan demonstration programme. The intake liner will be assembled to the Advanced Low Pressure System (ALPS) demonstrator engine being developed at Rolls-Royce’s facility in Derby, prior to ground testing.

SAGE comprises six separate research streams dedicated to demonstrating new engine technologies for a range of future civil aerospace applications. Bombardier Belfast, which has significant expertise in nacelle technology development, has been leading a €3.75 million project within SAGE3, known as SAGE3 ALTD (Intake Acoustic Liner Technology Development), with research partners the Irish Centre for Composites Research at the University of Limerick and the Institute of Sound and Vibration Research, University of Southampton.