Effects of inflow turbulence on structural response of wind turbine blades

A better understanding of the intense interaction between the turbulent inflow and rotating wind turbine components is critical to accelerating the path towards larger wind turbines. The present investigation provides the first field characterization of the influence of turbulent inflow on the blade structural response of a utility-scale wind turbine, using the unique facility available at the Eolos Wind Energy Research Station. A representative dataset under a stable atmosphere is selected for the characterization, including the inflow turbulent data measured from the meteorological tower, high-resolution blade strain measurement at different circumferential and radiation positions along the blade, and the wind turbine operational conditions. The results indicate that the blade response to turbulence shows distinct trends under three scale ranges. The blade structure responds strongly to the turbulent inflow in the lower and intermediate ranges, while it is primarily dominated by the rotation effect and other high-frequency characteristics of the turbine in higher frequencies. Moreover, the blade structural behaviors at different azimuth angles, circumferential and radial locations along the blade are compared, suggesting the comparatively high possibility of structural failure at certain positions. Further, the present study uncovers the linkage between the turbulent inflow and blade structural response using temporal correlation.