UK Engineers open flight path to quieter aircraft

A new international project to reduce aircraft noise is building on pioneering research by UK engineers.

The Cambridge-MIT Institute’s Silent Aircraft Initiative (SAI) aims to design an aircraft that will make much less noise than conventional aeroplanes. To help meet its objectives, the project will use noise-modelling techniques devised by engineers at Cambridge University with funding from the Engineering and Physical Sciences Research Council (EPSRC). As well as Cambridge University, participants in the SAI include the Massachusetts Institute of Technology (MIT) and a number of other organisations.

Noise is a major aviation issue that will become even more pressing in future, with a 300% increase in air traffic forecast by 2020. This could have a major impact on the quality of life of people living close to airports. The SAI represents a response to the problem. It will take an integrated approach to aircraft design and operations, and investigate radically different aircraft configurations that could lead to dramatic reductions in noise.

The SAI will build on results from two EPSRC-funded projects. The first has led to the development of computationally efficient calculations of the noise made by helicopter blades moving at high subsonic speeds. It involved developing innovative but simple computer-based models that can provide a better understanding of how noise is produced during flight.

The second project is looking at jet noise. It aims to develop a prediction capability for jet noise which can be used, for instance, to assess how incorporating serrations or other modifications into jet engines can reduce jet noise at take-off. Achieving this will involve developing a computer model capable of predicting jet noise, improving understanding of noise source mechanisms, and identifying potential ways of modifying these mechanisms.

The Cambridge team involved in these two projects are now harnessing their expertise in a different way. Professor Ann Dowling of Cambridge University, who is leading the SAI, says: “The Initiative is not just about understanding and modelling aircraft noise. It aims to have an impact on the aerospace industry, and people living near airports, by developing designs and operational procedures for a radically different type of aircraft – an aircraft whose noise is almost imperceptible to the surrounding community.”