Effect of wave nonlinearity on fatigue damage and extreme responses of a semi-submersible floating wind turbine |
| |
| Institution: | 1. Department of Marine Technology, Norwegian University of Science and Technology (NTNU), Trondheim 7491, Norway;2. Shandong Provincial Key Lab of Ocean Engineering, Ocean University of China, Qingdao 266100, China;3. Department of Mechanical Engineering, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark;4. Shipbuilding Engineering Institute, Harbin Engineering University, 150001 Harbin, China;5. Centre for Ships and Ocean Structures (CESOS), NTNU, Trondheim 7491, Norway;6. Centre for Autonomous Marine Operations and Systems (AMOS), NTNU, Trondheim 7491, Norway |
| |
| Abstract: | Floating wind turbine has been the highlight in offshore wind industry lately. There has been great effort on developing highly sophisticated numerical model to better understand its hydrodynamic behaviour. A engineering-practical method to study the nonlinear wave effects on floating wind turbine has been recently developed. Based on the method established, the focus of this paper is to quantify the wave nonlinearity effect due to nonlinear wave kinematics by comparing the structural responses of floating wind turbine when exposed to irregular linear Airy wave and fully nonlinear wave. Critical responses and fatigue damage are studied in operational conditions and short-term extreme values are predicted in extreme conditions respectively. In the operational condition, wind effects are dominating the mean value and standard deviation of most responses except floater heave motion. The fatigue damage at the tower base is dominated by wind effects. The fatigue damage for the mooring line is more influenced by wind effects for conditions with small wave and wave effects for conditions with large wave. The wave nonlinearity effect becomes significant for surge and mooring line tension for large waves while floater heave, pitch motion, tower base bending moment and pontoon axial force are less sensitive to the nonlinear wave effect. In the extreme condition, linear wave theory underestimates wave elevation, floater surge motion and mooring line tension compared with fully nonlinear wave theory while quite close results are predicted for other responses. |
| |
| Keywords: | Fully nonlinear wave effect Floating wind turbine Extreme value Fatigue damage |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
