Numerical Simulations of OC3 Spar and OC4 Semi-Submersible Type Platforms Under Extreme Conditions in the East Sea, Korea

Since the Paris Conference of the parties in 2015, interest in renewable energy around the world is higher than ever. Korea also has plans to increase the proportion of renewable energy to 20% by 2030 through the renewable energy 3020 policy. Of these, 16.5GW is filled with wind power, the installation area is expanding from land to sea. Among them, some of big plans are using floating offshore wind turbines based on the marine environments in Korea. In this study, numerical simulations of the NREL 5MW wind turbine were performed using NREL FAST V.8. A comparison was made between two types of floaters, spar and semi-submersible, installed 58km off the Ulsan Coast with 150m water depth in the East Sea, Korea. The environmental data were obtained from the Meteorological Administration’s measured data and NASA’s reanalysis data, MERRA-2. Design Load Cases were selected by referring to IEC 61400-3. Maximum moments at both blade root and tower base, six-degrees of freedom motions and three mooring line tensions were compared.