PDF Basket
One in four Europeans are exposed to potentially harmful noise levels, with air, rail and road transport frequently to blame. Common complaints are sleep deprivation, poor concentration and stress. Noise pollution has also been linked to diabetes, stroke and heart attack.
The EU-funded MID-FREQUENCY project pared the problem back to its physical roots by developing new modelling tools covering a neglected mid-frequency acoustic range of noise and vibration. Armed with new insight from the project, transport and industry are now in a position to develop and optimise machinery accordingly.
“Aware of the importance noise and vibration play in machine and engine design, especially in the aerospace and automotive sectors, we combined acoustic analyses with virtual design and prototyping to develop models for reducing cost and development time for safer, quieter and more comfortable machinery,” says Bert Pluymers of Katholieke Universiteit (KU) Leuven in Belgium.
Tackling complex design challenges
Health, safety and environmental laws exist to protect citizens and workers from excessive noise and vibration levels. Therefore, heavy machinery and toolmakers need to be on top of their game to meet these requirements. Today, virtual design and prototyping is an important measure to help them reduce costs and development times.
MID-FREQUENCY researchers and associates developed functional models using enhanced computer-aided engineering (CAE) methods to deal with this complex challenge. They focused on the neglected mid-frequency range in vibro-acoustic-wave analysis.
“To test low-frequency impacts of machinery, approaches such as finite element analysis or FEA exist. For high frequencies, typically statistical energy analysis (SEA) or similar approaches are used,” says Wim Desmet, also of KU Leuven.
“But before we started MID-FREQUENCY, there was a big ‘mid-frequency’ gap in modelling capabilities which posed industrial design challenges. It was basically too high for FEA and too low for SEA.”
MID-FREQUENCY’s approaches have really helped to plug that gap. They include a ‘variational predictive’ technique called VCTR, a type of wave-based modelling called WBM and a hybrid FEA-SEA approach applied to vibro-acoustic problem-solving.
Key industry component
The key ingredient in the mix, according to Pluymers and Desmet who co-managed the training network for young and upcoming research fellows that received funding through the EU’s Marie Skłodowska-Curie actions programme, was the involvement of industrial research groups like EADS Astrium (Airbus), Siemens and Daimler.
Several of the fellows now work at the cutting edge in CAE and modelling for noise suppression. The modelling approaches coming out of the project have been taken up by several of the partners and are now used in the development of new vehicles and machines, according to Pluymers and Desmet.
Together, the findings have made a significant contribution to noise and vibration suppression, especially in the automotive and aerospace sectors, and given unprecedented career opportunities to 23 fellows, 19 early-stage and four experienced researchers.
The training and collaboration platform led to knowledge innovations and numerous publications, including a free book summarising the theoretical development of the modelling approaches studied along with an assessment of their industrial applicability.