Session: 06-05-01 Marine Hydrodynamics I

Paper Number: 78799

78799 - Nonlinear Hydrostatic Restoring Characteristics of a Spar Floating Wind Turbine 

With the maturity of floating wind turbine technology，floating wind turbine technologies have found worldwide applications. The higher requirement has been put forward to evaluate the floating stability of the wind turbine under different sea conditions. Regarding the floater stability, there are three principal design philosophies: ballast- stabilised, buoyancy- stabilised and mooring-stabilised. As the fact that the accuracy of linear hydrostatic stiffness matrix may not be sufficient, accurate consideration of the nonlinear hydrostatic restoring forces is important for the evaluation of floating stability and design of load cases.

This work selects two representatives for offshore floating wind turbine (FWT) systems: spar-buoyancy platform and semi-submersible platform. A numerically calculated hydrostatic restoring stiffness for different heeling angles is presented for this purpose. By applying the strip theory and hydrostatics, the restoring stiffness can be computed.The heeling about the critical axis shall be studied, which might combine roll and pitch. To verify the method, the results are compared against the linear hydrostatic restoring stiffness matrix calculated by standard software,in which the main parameters are needed. Some interesting observations are reported. The results of this study can be further applied in the evaluation of the hydrostatic restoring stability and time-domain simulations of floating wind turbines.

Presenting Author: Zhengyang Pang Shanghai Jiaotong University

Authors:

Zhengyang Pang Shanghai Jiaotong University
Aichun Feng Shanghai Jiaotong University
Zhiyu Jiang University of Agder
Amrit Shankar Verma The University of Maine
Ke Chen Shanghai Jiaotong University