The effects of Coriolis forces on the wake phenomenon within a wind farm : a Large Eddy Simulation study

Enhancing our insight into wind farm physics is key in order to improve wind energy production capabilities thereby facilitating energetic transition. Different phenomena should therefore be studied such as the impact of the wind farm configuration or of the wind turbine rotational direction. The behaviour of the wind in the Atmospheric Boundary Layer (ABL) is governed by multiple phenomena such as the Coriolis effect. In this work, the implementation in an in-house developed Navier-Stokes equation solver and the validation of a Coriolis effect model is presented. The validation process is performed against two different test cases in Direct Numerical Simulation (DNS): a rotating channel with Re_{\tau} = 194 and a laminar Ekman layer; and over one wall-modeled Large Eddy Simulation (wmLES) case: the turbulent Ekman layer. The impact of this effect on a small wind farm is then studied. The turbines are modeled with actuator disks. The results indicate a positive impact of the Coriolis Effect on the power output of the wind farm and it also induces a deformation of the wake combined with a deflection of its trajectory. Finally, the last study focuses on the effect of the rotational direction of the wind turbines. Some differences were observed in the wake deformation but no major impacts were noticed in term of energy production. The trajectory of the wake is also slightly influenced by the rotating direction of the turbines.