Offshore wind power generation is a key component of the UK's commitment to deliver 15% of gross final energy consumption from renewable sources by 2020. Efforts to meet this target are prompting the design of ever larger turbines in order to capture more energy from the wind. However, as these structures grow taller, they become increasingly vulnerable to violent gusts of wind and other turbulent flow phenomena that are the primary cause of severe turbine damage. Advance warning of such gusts will enable turbine control systems to take preventative action, and so the ability to predict the strength of an oncoming gust is widely regarded within the wind energy industry as being a problem of critical importance. This research project will seek to overcome this problem by demonstrating a system that can accurately forecast the velocity profile of an oncoming wind, given only limited spatial measurements from state-of-the-art light detection and ranging (LIDAR) units. This approach will exploit recent interdisciplinary advances in the application of optimal estimation techniques, from the control systems community, to fluid-mechanical systems governed by the Navier-Stokes equations. The research will draw upon the PI's existing expertise in dynamical estimation of fluid flows and the project results will feed into the host institute's current industrial collaboration with Vestas Wind Systems, who have agreed to provide the data and technical support required to maximise research impact.

The Department for Transport forecasts that by 2020 the number of passengers using UK airports will be around 400 million, compared to 200 million today. Aviation noise represents a major obstacle to the future expansion of many existing airports and thus the growth in the capacity of the air transport system. In 2001 the Advisory Council for Aeronautics Research in Europe (ACARE) set out a target to reduce perceived aviation noise to one half of the current level by 2020. To achieve the ACARE target by the year 2020 a "technology breakthrough" is urgently needed. Wind turbine manufacturers also require new technology for the significant reduction of aerodynamic noise in order to make wind turbines more acceptable to communities, especially concerned with onshore wind farms. Such a technology breakthrough can only be achieved through a fundamental evaluation and re-design of aerofoils, particularly the "leading edges" (LE), since upstream turbulent flows impinging on the LE of an aerofoil is believed to be the dominant source mechanism of broadband noise in turbofan engines (rotor wakes scattered by the outlet guide vanes - OGV) and wind farms (upstream rotor wakes scattered by the downstream turbine blades). In turbofan engines, it is envisaged that new LE design would be applied to the OGV since noise reductions can only be achieved by modifying the OGV response or the rotor wake turbulence (much more difficult). The proposed 30-month research project aims to develop and investigate new aerofoil LE designs for the reduction of the broadband noise generated by the interaction between the aerofoil's LE and impinging turbulent flows, whilst minimising its impact on aerodynamic performance. The new aerofoil LE designs will be constructed by combining "smooth" spectral (wavy) serrations with multiple wavelengths, which has never before been attempted. In this project, a coordinated aeroacoustic and aerodynamic study of this new LE topology is proposed, particularly focused on the effects of smaller wavelengths (comparable to the impinging turbulence length scale), which are expected to be effective in reducing noise without making a significant impact on aerodynamic performance. The proposed project will take full advantage of the experimental and computational expertise of the two investigators. The successful outcome of this project will lead to a new aerofoil LE design that offers maximum noise reduction and minimum aerodynamic penalty. The commercial and academic impact of this work is potentially substantial. The proposed research programme will be largely split and managed in four stages: 1) testing baseline aerofoil models for calibration and validation purposes; 2) identifying the most effective Fourier modes of the proposed LE serrations with respect to noise reduction; 3) combining the identified individual Fourier modes into an integrated spectral LE design (8 models in total) and testing the aerodynamic performance as well as the overall noise reduction; and 4) further understanding and improving the most favourable design found in Stage 3 via detailed numerical simulations. The experimental measurements will be performed in our AWT (anechoic wind tunnel) facilities. The numerical simulations will be carried out by using CAA (computational aeroacoustics) techniques. The CAA and AWT activities are closely coordinated and mutually supportive to ensure maximum value to the project. The proposed study will be based on a NACA65(1)-210 aerofoil with the Reynolds number up to 1.1x10^6 and the Mach number of 0.3 to 0.6. The length scales of impinging free-stream turbulence will be determined and generated in accordance with the guidelines from the industrial partners representing the aero-engine and wind turbine industries.

The Horizon CL5 call D3-01-14 asks for a) Condition and Health Monitoring and b) Wide Bandgap and Ultra-Wide Bandgap power electronics for the energy sector with a focus on converters for wind farms and the DC grid. The MoWiLife consortium addresses this call with the most advanced technology. Basis for the four MoWiLife pilots is a 2.3 kV SiC MOSFET, which will be developed by project partner Infineon. It includes a source-gate PiN diode, whose on-state voltage has a strong temperature dependence and can be read out by the gate drive, which will be developed by Rostock University. In addition, self-protection features will be integrated into the SiC chip for robustness and direct water cooling will be realized for higher output power. Two wind energy converter pilots are being realized in MoWiLife by two industrial partners. As one of the technology leaders in wind energy, Vestas – supported by University of Aalborg – will realize a TRL 6 SiC converter with +20% power density and digital-twin Condition and Health Monitoring. The start-up RKL together with Rostock University will develop a TRL 5 wind energy power stack with Condition and Health Monitoring based on online chip temperature and on-state voltage measurement. Solar medium voltage DC collection grids and meshed high voltage transmission grids will play an important role in the future. As third and fourth pilots, a TRL 5 DC-DC converter and a TRL 5 DC circuit breaker including condition monitoring are being developed by the MoWiLife university partners KTH Stockholm and University of Aberdeen. While SiC is today’s Wide Bandgap material for high power applications, ultra-high voltage Ultra-Wide Bandgap semiconductors may allow further efficiency improvements for future HVDC converters. The MoWiLife industrial partner DiamFab together with two IUNET universities will work on diamond as the ultimate semiconductor material. The TRL is still low but the potential for energy saving is high.