Influence of Model Simplifications Excitation Force in Surge for a Floating Foundation for Offshore Wind Turbines

Energies

Morten Thøtt Andersen¹  Dennis Hindhede²  Jimmy Lauridsen² 

[1] Department of Civil Engineering, Aalborg University, Sofiendalsvej 11, 9200 Aalborg SV, Denmark;Department of Civil Engineering, Aarhus University, Inge Lehmanns Gade 10, 8000 Aarhus C, Denmark; E-Mails:

关键词: wave force;    surge;    experimental;    semi-submersible;    offshore;    floating foundation;   

DOI  :  10.3390/en8043212

来源: mdpi

【 摘 要 】

As offshore wind turbines move towards deeper and more distant sites, the concept of floating foundations is a potential technically and economically attractive alternative to the traditional fixed foundations. Unlike the well-studied monopile, the geometry of a floating foundation is complex and, thereby, increases the difficulty in wave force determination due to limitations of the commonly used simplified methods. This paper deals with a physical model test of the hydrodynamic excitation force in surge on a fixed three-columned structure intended as a floating foundation for offshore wind turbines. The experiments were conducted in a wave basin at Aalborg University. The test results are compared with a Boundary Element Method code based on linear diffraction theory for different wave force regimes defined by the column diameter, wave heights and lengths. Furthermore, the study investigates the influence of incident wave direction and stabilizing heave-plates. The structure can be divided into primary, secondary and tertiary parts, defined by the columns, heave-plates and braces to determine the excitation force in surge. The test results are in good agreement with the numerical computation for the primary parts only, which leads to simplified determination of peak frequencies and corresponding dominant force regime.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.