Fluid-structure interaction analysis of wind turbine aerodynamic loads and aeroelastic responses considering blade and tower flexibility

Abstract

With the increasing size of wind turbines, the aeroelastic phenomenon plays an essential role in the safety of wind turbines. A fluid-structure interaction (FSI) analysis for wind turbine by integrating the LES turbulent model and a structural dynamic model is carried out to investigate the aerodynamic loads and aeroelastic responses considering different inflow conditions, and blade and tower flexibility. For the first time, the time series and statistical features of aerodynamic loads, the exceedance probability, the equivalent fatigue loads, and the time series and statistical features of aeroelastic responses of wind turbine are calculated by the two-way FSI model. Furthermore, effects of inflow wind conditions and the blade and tower flexibility are investigated. It is noted that the turbulent winds result in increased fluctuations of aerodynamic loads and the equivalent fatigue load. The flap-wise motions of blades are more critical to load magnitude than the edgewise motions, and the inclusion of tower motion mitigates this aerodynamic load due to the coupling effects. Finally, it is also observed that the tower motion has a noticeable impact on the flap-wise displacement at the blade tip, and the flap-wise motions of blades significantly affect the fore-aft displacement at the tower top.