13 ESRs hosted by 10 institutions worked together in the FLOAWER project. They focused on four scientific challenges (Work Packages - WP):
WP4: Wind resource assessment in deep waters
ESR1, Telem Avidor, studied the wind resource assessment by the combination of spatially distributed measurement systems. He used wind observations from lighthouse and floating lidar buoys and compared the wind data using the measure-correlate-predict method.
ESR2, Moritz Gräfe, processed wind data from a nacelle-mounted lidar on a FOWT. After correcting data from the system motion, the work was extended with a simulation of the motions coupled with an aero-elastic simulation to account for FOWT dynamics.
ESR3, Daniel Hatfield, analysed floating wind lidar buoy data to estimate the atmospheric stability. Wind lidar data from a ferry was investigated and compared to other data types to check the accuracy. He proposed a vertical extrapolation of satellite ocean winds to turbine hub-height using machine learning.
WP5: Advanced floater analysis
ESR4, Xiaoming Ran, studied how the combination of nonlinear wave loads and floater flexibility affects the tendon responses for a tension leg platform.The importance of nonlinear wave loads for the load effects in the flexible floater are seen to be more important for the TLP than for the spar.
ESR5, Seung-Yoon Han, produced an extensive database of hydrodynamic loads on a vertical column with a heave plate, and compared the results against CFD and a simplified model based on potential flow and Morison’s equation.
ESR6, Navid Belvasi, carried out experimental measurements of the flow around a FOWT hull. Particle image velocimetry was used to give insights about the details of the flow. It is an important tool for validation of higher fidelity methods such as computational fluid dynamics.
ESR7, Eva Schmitt, improved the optimization framework for FOWT mooring systems. He concluded that better modelling of the power cable is required to enable such a design optimization, and that the power cable geometry must be included in an efficient manner.
WP6: Dynamics of wind turbines
ESR9, Mariana Montenegro, investigated numerical engineering aerodynamic models of different complexity for Horizontal and Vertical Axis Wind Turbines. She focused on the response of wind turbines to platform motions, highlighting the different response of horizontal and vertical axis wind turbines.
ESR10, Thomas Messmer, further developed a new experimental set-up to investigate the wake development and dynamics of FOW. The motion allows a faster transition to the far wake compared with the wake of the fixed turbine, linked to nonlinear spatiotemporal dynamics in the shear layer region of the wake.
ESR11, Wessel van der Deijl, performed a deep experimental analysis of the wake of a vertical-axis wind turbine designed for floating conditions. The opportunity to perform experiments in different wind tunnels enabled to assess the sensitivity of the experimental results to facility properties.
WP7: System design to reduce LCOE
ESR8, Victor Benifla, developed a comprehensive framework for optimizing the design of FOWT substructures using frequency domain analysis and Genetic Algorithm.
ESR12, Kutay Yilmazlar, focused on the research activity on the integrated design of FOWTs with the aim of minimizing LCoE. A novel wind farm design methodology was presented, integrating design variables from different design aspects into an optimization problem.
ESR13, Daniel Craig, developed a techno-economic tool to analyse the LCoE under various boundary conditions. He plugged the gap in research through a range of dynamic functions that address this by adapting to site and technical conditions and are only limited by the ability to predict future commodity prices.
16 journal publications (17+ expected after the end of the project), 47 talks and 21 posters in international conferences, and 2 brochures were produced, witnessing the large impact on the targeted audience. They were designed to target specific audiences (industry and policy makers, respectively). A book on FLOAWER results is under evaluation by Springer for publication in the book series “Research Topics in Wind Energy” of the European Academy of Wind Energy.
