analysis of the induction and wake evolution of an offshore floating wind turbine归纳和分析进化后的海上浮动式风力涡轮机.pdfVIP

Energies 2012, 5, 968-1000; doi:10.3390/en5040968 OPEN ACCESS energies ISSN 1996-1073 /journal/energies Article Analysis of the Induction and Wake Evolution of an Offshore Floating Wind Turbine Thomas Sebastian * and Matthew Lackner Department of Mechanical and Industrial Engineering, University of Massachusetts, 160 Governors Drive, Amherst, MA 01003-9265, USA; E-Mail: lackner@ * Author to whom correspondence should be addressed; E-Mail: tommy.sebastian@. Received: 3 February 2012; in revised form: 29 March 2012 / Accepted: 9 April 2012 / Published: 17 April 2012 Abstract: The degrees-of-freedom associated with offshore floating wind turbines (OFWTs) result in a more dynamic flow field. The resulting aerodynamic loads may be significantly influenced by these motions via perturbations in the evolving wake. This is of great interest in terms of OFWT design, placement and simulation. This study presents free vortex wake method (FVM) simulations of the NREL 5-MW wind turbine of a variety of platforms, operating in a range of wind speeds synthesized platform motion time series. Motion-induced wake perturbations are observed to affect induction. Transitions between windmill and propeller states are also observed. Keywords: offshore floating wind turbine; free vortex wake method; wake evolution Nomenclature Once per revolution Significant wave height Amplitude Gain Axial induction