Wind-tunnel experiments were performed to study the wind characteristics on a parked wind turbine downwind of three types of hill and over a flat terrain. The focus of the study is on comparing wind characteristics on (a) a wind turbine standing alone and (b) this same type of wind turbine embedded in a wind farm. Particular emphasis is placed on the hill size and shape and the distance between the hill and the wind farm. The hill and wind-farm models were subjected to an atmospheric boundary layer simulation to create realistic atmospheric conditions. Flow and turbulence were analyzed based on the measured mean flow velocity, Reynolds shear stress, turbulence intensity, and the power spectral density of velocity fluctuations. The experimental results reveal similar trends concerning (a) the wind characteristics obtained on a parked wind turbine embedded in a wind farm downwind of hills of various sizes and shapes and (b) the wind characteristics on this same type of parked wind turbine standing alone in the same position downwind of the same hills. In particular, the discrepancies in the mean flow velocity and turbulence intensity between these test cases are mostly below 5%, thus indicating that a complex terrain clearly has a dominant effect on the wind characteristics, while the effects of parked wind turbines on the wind characteristics are negligible. This important finding indicates that the structural loading of parked wind turbines situated on a complex terrain may be well calculated using the same procedures both for wind turbines standing alone and wind turbines embedded in wind farms if they are both placed at the same distance downwind of the same hills.

中文翻译：

---

在复杂地形上停放的风力涡轮机对风流和湍流的影响

进行风洞实验以研究停放的风力涡轮机在三种类型的山丘下风和平坦地形上的风特性。研究的重点是比较 (a) 独立的风力涡轮机和 (b) 嵌入风电场的相同类型的风力涡轮机的风力特性。特别强调山丘的大小和形状以及山丘与风电场之间的距离。山丘和风电场模型经过大气边界层模拟，以创建逼真的大气条件。基于测量的平均流速、雷诺剪切应力、湍流强度和速度波动的功率谱密度分析流动和湍流。实验结果揭示了类似的趋势，涉及（a）在不同大小和形状的山下风场中嵌入风电场的停放风力涡轮机上获得的风特性和（b）同一类型停放风力涡轮机的风特性。相同山丘下风向的相同位置。特别是，这些测试案例之间的平均流速和湍流强度的差异大多在5%以下，这表明复杂地形对风特性的影响明显，而停放的风机对风特性的影响可以忽略不计。