Large-eddy simulation of wind turbine wake characteristics over a two-dimensional hill

Hilly terrain can significantly affect the wake characteristics of wind turbines. In this paper, the effects of terrain slope, wind turbine location, and wind turbine–terrain size ratio on wind turbine wake characteristics are systematically investigated. First, a high-fidelity large-eddy simulation framework is established based on the actuator line model, and validated by comparing with the wind tunnel test results. Subsequently, several key characteristics of wind turbine wake, including wake-center trajectory, velocity deficit, and added turbulence intensity, are systematically investigated, and the related flow mechanisms are elaborated via analysis of mean kinetic energy. It is found that the interaction between the turbine and hill-induced wakes alters the wake center trajectory significantly. Steep hills amplify wake–terrain interactions, producing higher velocity deficits and negative turbulence in the leeward region, indicative of strong nonlinear effects. Furthermore, wake recovery over complex terrain is primarily governed by the pressure gradient on windward slopes and hilltops, and a large terrain-to-turbine ratio amplifies the role of turbulence-driven energy redistribution.