Session: 09-01-08: Offshore Wind Energy - Hydrodynamics 2

Paper Number: 107853

107853 - Influence of Hydrodynamic Damping Model on Floater and Mooring Responses of 10mw Class Floating Offshore Wind Turbine 

In this study, the influence of the hydrodynamic damping model of the semi-submersible type floating offshore wind turbine (FOWT) on the floater and mooring dynamics were verified numerically and experimentally. Most of the FOWT substructures currently being developed are semi-submersible type and consist of a combination of multiple pontoons and vertical columns. These structures submerged in the sea water undergo dynamic behavior in the fluid domain under the influence of waves and currents. The drag force due to the shape of the structure and the damping force due to the viscosity of the fluid act in a complex way to affect the dynamic motion of the floater and mooring tensions. In the initial stage of design, an integrated load analysis is performed to estimate the response characteristics of the structure. At this time, if an appropriate level of drag coefficient or damping coefficient is not applied to the floating structure, the motion of the floating body may be underestimated or overestimated. Since this affects the reliability of the entire structure, it is very important to select an appropriate damping model that can simulate the damping characteristics of the actual structure as closely as possible. The floating substructure used in this study is a semi-submersible type composed of three outer columns and one center column, and a DTU 10MW turbine is mounted at the center column. In order to select the optimal damping model, the numerical method using the CFD technique, and the experimental method based on the 1/36 scale model test were simultaneously utilized. Through this, linear and quadratic damping coefficients and nonlinear Morison drag coefficients applicable to time-domain simulation were obtained and their characteristics were compared. In addition, an appropriate combination method of the obtained damping models was presented, and its validity was confirmed by applying it to this floating substructure.

Presenting Author: Eungsoo Kim POSCO

Presenting Author Biography: Senior Research/Ph.D./PE
Steel Solution R&D Center, Steel Structure Research Group
POSCO

Authors:

Eungsoo Kim POSCO
Dongeun Kim Jeju National University
Sunny Kumar Poguluri Hongik University
Yoon Hyeok Bae Hongik University
Yoon-Jin Ha Korea Research Institute of Ships and Ocean Engineering
Ji Yong Park Korea Research Institute of Ships and Ocean Engineering
Jeongbin Kim Marine Tech-In