Aeroelastic analysis of wind turbine under diverse inflow conditions

As wind turbine blades increase in size and flexibility, the structural deformation becomes more pronounced and significantly influences the aerodynamic performance of the wind turbine. This paper introduces a fluid-structure interaction (FSI) analysis model that employs the actuator line technique and equivalent beam theory to assess the aeroelastic behaviour of wind turbines under various inflow scenarios. After validating the FSI model, it is used to simulate the aeroelastic responses of the NREL 5 MW wind turbine under various inflow conditions. The aerodynamic loads, structural dynamic responses, and wake field characteristics are thoroughly analysed, detailing the effects of various inflow conditions, such as wind speed and inflow type, on the aeroelasticity of the wind turbine. The findings reveal that blade deformation reduces average aerodynamic loads under various inflow conditions, with the effect intensifying at higher wind speeds. Blade deformation's impact is more profound on aerodynamic thrust than on aerodynamic power, and it significantly influences the variation amplitude of aerodynamic loads rather than their average values. Additionally, with increasing wind speed, blade deformation notably increases wake velocity and reduces wake field turbulence intensity. Under turbulent inflow, however, the rise in wake velocity due to blade deformation diminishes, while turbulence intensity increases, comparing with uniform and shear inflow conditions.