A Comprehensive Aero-Hydro-Structural Analysis of a 5 MW Offshore Wind Turbine System

A comprehensive aero-hydro-structural analysis is conducted for a 5 MW offshore wind turbine system in this study. Soil–structure interaction under complex aero-hydro loading is analyzed to provide a suitable foundation design with high safety. With consideration of the wind turbine size and water depth, the monopile foundation design by the National Renewable Energy Laboratory (NREL) is selected in the current study. Both aerodynamic loading for the 5 MW wind turbine rotor defined by NREL and hydrodynamic loading on the foundation are simulated under different flow conditions using high-fidelity computational fluid dynamics methods. Structural dynamic analysis is then carried out to estimate the stress field in the foundation and soil. Results from the comprehensive analysis indicate that the Morison equation is conservative when looking at the stress field in the monopile foundation and underestimates the stress field in soil. A similar analysis strategy can be applied to other types of foundations such as jacket foundations and lead to more economical and reliable designs of foundations.