This study examines extreme response statistics for a monopile-supported 5-MW offshore wind turbine in 20 meters of water that is subjected to coupled wind and wave input fields during a hurricane. Over approximately 120 hours, these hurricane-induced input fields yield changing characteristics of the excitation and the response of a parked turbine. As the storm evolves, the directionality of the wind and waves changes; short-crested waves are simulated and associated wind velocity fields are generated. Aerodynamic loads on the rotor and hydrodynamic loads on the support structure are simulated in coupled response analyses. Because yaw control backup power is not assured during the hurricane, different assumptions on yaw misalignment are assumed in the turbine response simulations. Time series of various turbine response measures are evaluated. Response extremes are of particular interest; we discuss the relative importance of wind and waves on the overall turbine performance during the storm. We also assess the role of yaw control systems and the effect of loss of power to such systems during tropical storms by examining the turbine response for alternative situations of turbine misalignment. Ultimately, this study seeks to provide the framework for assessing turbine designs for tropical cyclone conditions.
Uncertainty modeling in reliability analysis of floating wind turbine support structures