‘SILENCE(R)’ aircraft noise reduction project holds final meeting
The final meeting of the EU-funded SILENCE(R) project took place in La Baule, France, on 27 June 2007. For over six years, SILENCE(R) has been at the leading edge of new aircraft noise reduction technologies, bringing together representatives of the European aviation industry including Airbus, Rolls-Royce, MTU Aero Engines and Snecma, along with the research community and universities.
“The SILENCE(R) project has successfully demonstrated the ability of European industry and research organisations to deliver innovative noise reduction technologies for tomorrow’s aircraft,” said programme coordinator Eugène Kors of Snecma. “Tests carried out within the scope of SILENCE(R) have generated magnificent results, allowing us to take a major step towards more environmentally-friendly engines and airframes.”
The project’s main objective was the validation of individual technologies and a cost/benefit analysis of technological applications across the product range. Kors says SILENCE(R) has met its goal of validating large-scale noise reduction solutions regarding various noise-generating aircraft elements, including:
- Engine– research on engine noise spanned fan, compressor, turbine and jet noise.
- Nacelle(the engine housing) – research focused on both nacelle geometry and acoustic liners.
- Airframe– extensive airframe noise tests focused on technologies to reduce landing gear noise and noise generated by high-lift devices (flaps, etc.).
Combined with innovative low-noise operational procedures studied at the same time, SILENCE(R) has achieved an impressive 5 dB noise reduction, representing significant progress towards the goal of a 10 dB reduction in perceived aircraft noise by 2020, put forward in the Strategic Research Agenda of the Advisory Council for Aeronautics Research in Europe (ACARE).
“We carried out successful tests of more than 35 prototypes to check ten noise reduction technology concepts, ” explains Kors. “These included several advanced low-noise fan rotors, as well as components for a complete low-noise nacelle, flight tested on an Airbus A320.” Flight tests were also carried out on an Airbus A340 with landing gear fitted with aerodynamic fairings.
From research to application
Hervé Batard of Airbus said working with so many of Europe’s major aeronautics stakeholders, but also with academic bodies and smaller companies, was a gratifying experience. “Seeing all of these people working together on the same project was truly amazing,” he said, “We had manufacturers and theoreticians exchanging ideas and advice, with the European Commission providing just the right amount of guidance, all aimed at getting our new developments into production as quickly as possible.”
Some of the technologies developed under SILENCE(R) are already moving towards industrial application. “The new ‘zero-splice’ air intake is one example which is already being put into production,” said Rudolf Maier of EADS. “Other elements are also very nearly ready. There are definite business opportunities here, and benefits to be gained by producers.
Industry perspective provides solid basis for success
An important factor in the project’s success was a ‘matrix’ management structure, where responsibilities for strategic decisions required to ensure optimum development of specific technologies were separated from the actual execution of research. The involvement of industry specialists in the decision process ensured an unwavering focus on research objectives coupled with sound risk management.
SILENCE(R) was built upon an array of smaller projects, each budgeted at €10-15 million, which paved the way for work on airframe noise, turbomachinery noise and nacelle technologies. These projects, say organisers, made it easier to combine existing technologies and disciplines in the integrated SILENCE(R) project.
In addition, the technology evaluation process provided important insights into costs and benefits, contributing to decisions on whether to proceed to full-scale validation or to abandon a particular technology and concentrate resources on other, more promising areas. Towards the end of the project, the technology evaluation approach was also used to assess the overall benefits of SILENCE(R) technologies.
SILENCE(R) brought together some 50 partners, with an overall budget of €112 million, about half of which was contributed by the European Commission.
“SILENCE(R) has been one of our biggest and most important projects,” said Commission Scientific Officer Daniel Chiron, “and the conclusions are positive. Yes, it was worth it; now the important thing is that these results should be taken up by the manufacturers, to be transferred into ‘real life’ applications. It is up to them now to push for integration.”
Chiron addressed academic partners directly. “It is very important that we do the utmost to exploit the results of this project,” he said. “Our business partners will do this, but the universities must also make an effort to seek some commercial benefit. It is part of your responsibility as an EU project partner to exploit knowledge gained. Remember that we are using public money here and it is ultimately your job to deliver something in return, both in terms of increased economic competitiveness and benefits for European society as a whole.”
The SILENCE(R) program is linked to ‘X-NOISE’, a European Thematic Network on External Aircraft Noise.