Verification of continuous time random walk wind model
This paper is focused on analysis of impact of different methods for stochastic wind field generation on fatigue loads on several wind turbine components, such as: blade root, hub, yaw bearing and tower bottom. Three methods were compared: the Veers (Sandia) method with Kaimal spectrum, the Mann method and the Continuous Time Random Walk (CTRW) method. CTRW describes the intermittent and non-Gaussian properties of 3D turbulent flows, which are not accounted for in two previous methods. The simulations were carried out according to the third edition of the IEC 61400-1 standard. A numerical model of the state-of- the-art generic onshore 7.5MW wind turbine was used. Some first results have shown that the intermittency in the wind speed distribution impacts wind turbines loads. However, based on the obtained results it is difficult to explicitly state whether or not the intermittent wind fields would increase fatigue loads in overall.