High-fidelity simulations of wake-to-wake interaction in an atmospheric boundary layer over a complex terrain

Abstract In this work, the wind farm simulator WInc3D is employed to perform large-eddy simulations (LES) of the flow over a complex terrain. The methodology used is validated through comparison with previously published wind tunnel experiments and numerical data for the flow over a cosine-squared hill with and without wind turbines. The study focuses on the wake-to-wake interaction between two wind turbines, with one on the hilltop and the other 2.5 or 5 turbine diameters downstream of the hilltop. The results indicate that the power output of the downstream turbine can be increased by a factor of three when a wind turbine is placed on the hilltop. This is explained by the accelerated flow that results from the favourable pressure gradient produced by the first half of the hill and the blockage of the hilltop turbine. It is also found that this effect is not sufficient to enhance the power of the downstream turbine if it is placed too far away from the upstream turbine.