Large-eddy simulation of wind turbine wakes over laterally sinusoidal hilly terrain: Implications for wind farm layout optimization

Tite: Large-eddy simulation of wind turbine wakes over laterally sinusoidal hilly terrain: Implications for wind farm layout optimization (DOI)
​​​​​​​Authors:  Kokab Goharian, Maryam Hosseinzadeh Sereshgi, Mani Fathali.
Journal: European Journal of Mechanics - B/Fluids
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Abstract: Wind energy deployment in complex terrain is often constrained by wake-induced power losses and an incomplete understanding of terrain–wake interactions, particularly in topographies with pronounced lateral variations. Accurate characterization of wake recovery under such conditions is therefore essential for improving wind farm layout efficiency and energy yield. Large-eddy simulations (LES) are performed to investigate wind turbine wake development over laterally sinusoidal hilly terrain under neutrally stratified atmospheric boundary layer conditions. Unlike conventional studies focusing on streamwise-oriented or upwind hills, the present work examines crosswise terrain undulations that induce lateral flow curvature, asymmetric shear, and anisotropic turbulence. Three turbine placements – flat ground, hilltop, and valley – are analyzed to assess their influence on wake recovery and turbulence characteristics. The results show that the laterally undulating terrain induces measurable changes in the mean flow and turbulence structure, altering wake dynamics relative to the flat case. Hilltop placement is associated with increased vertical and lateral velocity transport, faster wake recovery, elevated turbulence levels, and higher streamwise turbulence intensity, whereas valley placement is characterized by deeper and more persistent velocity deficits. Across all configurations, streamwise turbulence intensity exhibited the strongest association with wake recovery among the turbulence quantities examined. These findings highlight the importance of terrain-aware wake modeling for wind farm design and provide practical guidance for turbine siting and layout optimization in complex terrain.