Validation of wind turbine wakes modelled by the Meso-NH LES solver under different cases of stability

Abstract

In wind farms, the wakes of upstream turbines impact the downstream ones in terms of power production, loads, and fatigue. The wake properties depend on many parameters such as the stratification, Coriolis force, large-scale forcing and orography. To simulate this interdependence, the actuator line method (ALM) has been implemented in the atmospheric code Meso-NH, which is an LES research code developed by the French weather services. This implementation has already been validated for the blade force distribution on the NewMexico case (uniform inflow in a wind tunnel) and for the interaction with the atmosphere on the Horns Rev photo case. The work presented here aims at completing the validation in a realistic atmospheric boundary layer (ABL), with a focus on velocity deficit and wake meandering. It is based on the international SWiFT benchmark which compares the results of many numerical models with LiDAR measurements in the wake of a single turbine for three cases of atmospheric stability: neutral, unstable and stable. The good results show the capacity of Meso-NH/ALM to generate realistic wakes in a representative ABL.