QUIET AEROFOILS OF THE NEXT GENERATION

Wind turbines and aircraft are well known to be noisy machines that limits their acceptability to people living close to their operation, such as wind farms and airports. This limitation of course has significant implications for the growth of the aerospace and renewable energy sectors, which is vital to the UK economy as a whole. Wind turbines and aircraft have common noise generation mechanisms, namely the interaction between the airfoil blades and wings with turbulent flow around it. Conventional airfoils have straight leading and trailing edges, which according to recent research by the authors of this proposal, is the noisiest geometrical configuration. Significant noise reductions in airfoil noise have been obtained by introducing serrations (or undulations) into the trailing edge and leading edge geometries. In separate studies, introducing riblets onto the airfoil surface (very fine grooves) have also been shown to produce significant reductions in drag. It is reasonable to assume that airfoil drag and its noise radiation are connected, although this has never been formally investigated. An investigation into this association is one of the objectives of this work. This project will seek to combine these three technologies into a single airfoil design for the simultaneous reduction of leading edge and trailing edge noise whilst preserving aerodynamic performance. This optimisation process will necessitate a fundamental understanding into their noise reductions mechanisms individually in order to ensure that their combined benefits are at least additive or may combine to be more effective than the sum of their benefits individually. The outcome of this work is a new generation of aerofoils with noise control at the heart of their design.