Dynamic Analysis of a Braceless Semisubmersible Offshore Wind Turbine in Operational Conditions

The development of cost effective floating type offshore wind turbines has been desired in deep sea areas. Semisubmersible platform can be considered as a very efficient design configuration among the different type proposed floating platforms. In the present paper, a preliminary assessment of the dynamic behavior of a 5-MW braceless semisubmersible offshore wind turbine with three columns and two fully submerged pontoons is presented for selected environmental operational conditions that correspond to a deep water offshore site with depth 200 m. Hydro-aero-servo-elastic time domain analysis is performed with the use of the coupled analysis tool Simo-Riflex-AeroDyn in order to calculate the dynamic behavior and response of the offshore floating wind turbine. Statistical values and spectra of time histories of response quantities are presented. The results demonstrate the feasibility of the presented deep sea floating wind turbine concept.