Comparison of blade and rotor loads with and without Gurney flaps

The fatigue loads are compared for two situations with and without gurney flaps using the equivalent load methods. The structural measurements are made on a NEG Micon 650kW wind turbine erected at a complex terrain high wind site in Oak Creek, California.
The turbine is located on the top of a ridge. The prevailing wind direction is perpendicular to the ridge, and the annual mean wind speed is 9.5 m/s. The associated wind field measurements, are taken from two instrumented masts erected less than one rotor diameter in front of the turbine in the prevailing wind direction. Both masts are instrumented at several heights in order to gain insight of the 3D-wind speed structure over the entire rotor plane. In this analysis, only the wind speed at 65m heights is used. The 65m correspond to the hub high of the turbine. The elevation from the mast to the turbine is around 10m.