In the aerospace industry, great emphasis is always placed on the lifting components to achieve high-lift, low-drag and low-noise performances. This proposal concerns an 18-month experimental study into the application of surface plasma actuators as an active boundary layer and wake control technique with the aim of reducing the drag and Trailing Edge self-noise of aerofoil. Two configurations will be investigated: (1) an aerofoil with blunt trailing edge - which characteristically combines a superior lift performance with high drag and significant tone noise radiation; (2) an aerofoil with a sharp trailing edge - which typically produces broadband self-noise in high Reynolds number flow. The main technology under investigation here is the relatively new, though rapidly expanding, surface plasma actuators. The usage of surface plasma actuators for flow control is very attractive for industrial applications because this technique is highly energy efficient, has a fast response, a simple structure, can be used for both steady and unsteady actuations and creates no profile drag when not in operation. The proposed research aims to simultaneously optimise the aerodynamical and aeroacoustical performances of aerofoil with blunt as well as sharp trailing edges. The expected outcome of this research is an extensive validation of the effectiveness of surface plasma actuator as a relatively novel technique for the reduction of drag and noise generated by aircraft components such as the turbofan engine and airframe. The outcome of this research is also transferable to the wind turbine industry and fan-based home appliance sector.

Potential Impact:
An active flow control method (Dielectric surface plasma) is proposed to reduce both the base-drag and trailing edge self-noise of aerofoils. The impact of this research to the academic circle, industrial sector, general public and governmental policy makers is significant. The academic impact has already been addressed in the "Academic beneficiaries" section. How this proposal can benefit the industrial sector, general public and governmental policy makers is detailed below:
It is envisaged that this research project can directly affect three types of industries: aerospace, wind turbine and fan-based home appliance manufacturers. For the aerospace industry, research and development into the "faster, higher and longer" technologies has reached a saturation phase where great emphasise is now placed on developing technology to sustain the above accomplishments with the lowest possible energy consumption and cost. The active flow control technology developed in this research can reduce the viscous or pressure drag caused by the turbulent or separated flows over the aircraft body or lifting surfaces, thus saving fuel, and consequently reducing the overall operational cost. The novelty of this research project, however, is to exploit the by-product as a result of the active flow control on drag reduction. This "by-product" is essentially the reduction of the noise sources on the foil surfaces and in the wake flow. Therefore, this research aims to reduce the drag force and self-noise radiation simultaneously. Nowadays, aerofoil self-noises generated by the aircraft fan engine, the airframe and the wind turbine (which has a characteristic swishing noise that can be heard at considerable distance) can affect the quality of life, and in some cases, personal health of the general public who reside near the airport or wind farm. These noise issues have already hampered the growths of airport capacity and onshore wind turbine installation significantly. The European Union and the UK government have two ambitious targets to be achieved by the year 2020. The first one originates from the Advisory Council for Aeronautics Research in Europe, where a target was set to reduce the perceived aviation noise to one half of the year 2001 level by 2020. The second one is the UK government's commitment to increase the share of renewable energy in the domestic usage to 15% by 2020. In 2011, the UK Department of Energy and Climate Change identified that extra wind power delivered by both onshore and offshore wind turbines is required to meet this 15% target. The proposed research will benefit directly aircraft and engine manufacturers seeking to design quieter aero-engines by establishing new control techniques for reducing the noise from rotor blades and aircraft wings, and wind turbine manufactures who aim to design the next generation turbine blades with low-noise and low-drag characteristics. This work will clearly benefit communities living in close proximity to airports or wind farms. Most importantly, technology developed in this work will have a direct beneficial impact on Europe and UK's efforts to achieve the two targets identified above, which ultimately can improve not only the quality of life for the general public, but also the economy of the country as a whole. The quest for the improvement of "quality of life" by the proposed research can also be extended to the general consumer of home appliances. An innovative electronic manufacturer is interested to adopt the fan noise control methodology to be developed in this research to their fan-based home appliance products, such as the air-conditioner, to produce a quiet operating condition. To summarise the impact of this research proposal, the technology developed here will appeal to a wide spectrum of industrial products ranging from large aircraft engine fans and wind turbine blades to small air-conditioner fans.