Abstract:
The wake behind a wind turbine in an atmospheric boundary layer (ABL) is investigated using a numerical simulation method. From the viewpoint of cost effectiveness, collective installations (wind farms) are desired because they can reduce the total length of the power-transmission lines and labor costs for maintenance. However, a wake from an upwind turbine may significantly reduce power production downstream and cause large load variations on the blades. Numerical methods based on computational fluid dynamics (CFD) are efficient for investigating the structures and characteristics of wind-turbine wakes. This study mainly discusses the effect of wind shear of ABL on a wind turbine wake by focusing on the behavior of tip vortices and recovery process of velocity deficits. It is found that the wind shear mainly influence on near-wake structure and the effect on far-wake is relatively weak.