Advances in Model Scale Testing of Floating Offshore Wind Turbines Utilizing the W~2 Wind/Wave Basin

摘要

Increased interest in floating offshore wind turbine (FOWT) technology has stimulated the developmentrnof new testing facilities and techniques to support the design of these structures. This paper presents somernspecific challenges of testing FOWTs and how these requirements have driven the development ofrnwind/wave basins capable of providing both high quality wind and wave environments necessary to testrnthese structures. Previous experience by the University of Maine (UMaine) and others as part of thernDeepCwind Consortium in testing 1/50th-scale FOWTs at the Maritime Research Institute Netherlandsrn(MARIN) Offshore Basin has supported the development of UMaine’s Harold Alfond W~2 OceanrnEngineering Laboratory (W~2), which includes a movable, open-jet wind machine specifically designed tornprovide a high quality wind field for testing FOWTs. A calibration testing campaign of this newlyrnconstructed facility will recreate a subset of the tests performed at MARIN. The new test campaign willrncontain system identification, wind turbine performance characterization, wave only, wind only, andrncombined wind/wave test cases utilizing both regular and irregular wave specifications. This paper willrnfocus on the initial phase of this campaign which includes select system identification and regular waverntests. The test specimen is the same used in the original test program performed at MARIN and consistsrnof the 1/50th-scale model semi-submersible along with the 1/50th-scale model version of the NationalrnRenewable Energy Laboratory (NREL) 5MW Reference Wind Turbine. Results from the new testrncampaign are studied and compared with the data from the 2011 MARIN test. Differences in datarncollection methods, basin geometry, model specifics and test methods were expected and are discussed forrnthis initial phase. In particular, differences in the basin geometry necessitate development of a truncatedrnmooring system to emulate the response of the full mooring system used at MARIN. The implications ofrnutilizing this method are discussed as well as additional areas of future work to be completed inrnsubsequent phases of the validation test campaign.