FloVAWT: Further Progresses on the Development of a Coupled Model of Dynamics for Floating Offshore VAWTS

• Published in: Volume 9B: Ocean Renewable Energy
• Main Authors: Collu, M, Borg, M, Shires, A, Rizzo, FN, Lupi, E
• Format: Report
• Language: unknown
• Published: ASME 2014
• Subjects: Arctic
• Online Access: https://eprints.whiterose.ac.uk/88883/; https://doi.org/10.1115/OMAE2014-24459

Interest in potential wind farm sites in deeper waters and further offshore has substantially increased recently, and in parallel an increased interest towards floating, rather than bottom-fixed, offshore wind turbines: the Energy Technologies Institute (UK) recently announced a plan to invest £25m in offshore floating wind turbine projects. Furthermore, a recent document by the UK LCICG (Low Carbon Innovation Coordination Group), demonstrated that the “Development and demonstration of new concepts such as floating foundations for water depths >60m”, has a value in meeting emissions targets at low cost of up to £13bn. The present article is a follow on with the previous article presented at OMAE 2013 [1], in which the progresses on the development of an aero-hydro-servo-elastic coupled model of dynamics for VAWT are illustrated, called FloVAWT. The further progresses presented consist in: a) the model, in particular the hydrodynamic module, has been now validated against experimental data provided by the DeepCwind project (see OC4) for the semi-submersible support structure configuration, b) the additional velocity component due to the 6 degree-of-freedom motion of the supporting floating structure are now taken into account within the aerodynamic module, while previously only the displacement imposed by the support structure was considered, c) a new module dedicated to the mooring system has been developed and validated, capable of modelling catenary mooring systems with a quasi-static, energy-based approach. Some of the new capabilities of the program are illustrated through a case study of a Darrieus-type VAWT rotor coupled with the OC4 semi-submersible support structure. Comparisons with the previous version of the program are presented, giving an insight on the relative importance of the additional aspects taken into account.