LiDAR measurements and modeling of onshore wind farms on flat and complex terrains

In order to understand and model interactions between the atmospheric boundary layer and multi-MW onshore wind farms, two experimental campaigns were carried out: the first one for a relatively flat terrain in Panhandle, TX, for which wind farm performance is mainly driven by the atmospheric stability, and a second site in Colorado characterized by a complex topography and low-level jets. Wind velocity measurements were performed through a scanning wind LiDAR, which are coupled with SCADA and meteorological data. LiDAR measurements of wind-turbine wakes are post-processed, clustered and ensemble-averaged based on atmospheric stability regime and operative conditions of the wind turbines. The resulting statistics of the wake velocity fields are used for tuning of a parabolic RANS model. Specifically, LiDAR data are leveraged for tuning the RANS turbulence closure for different atmospheric stability regimes and estimating thrust force over the blade span by coupling the LiDAR data and results of the respective RANS simulations. The RANS model is assessed against power production of individual turbines recorded through the SCADA showing a satisfactory agreement.