Analytical top-down and bottom-up wind-farm models have become major tools for quick assessment of yields from larger wind farms and the extension and properties of their wakes and have proven their principal applicability from recently obtained in situ observations. We review some of the limitations of top-down wind-farm models, partly in light of basic atmospheric boundary-layer findings which have been coined by the late Sergej Zilitinkevich. Essentially, for the applicability of such analytical models, the wind-farm turbine hub height should be small compared to the atmospheric boundary-layer height, and very small compared to the horizontal extension of the farm and the distance to the nearest surface inhomogeneities. Possibilities and options to include recently discovered blockage effects are also discussed.

自上而下和自下而上的风电场分析模型已成为快速评估大型风电场的产量及其尾流的延伸和特性的主要工具，并已从最近获得的现场观测证明其主要适用性。我们回顾了自上而下的风电场模型的一些局限性，部分是根据已故的 Sergej Zilitinkevich 提出的基本大气边界层发现。从本质上讲，对于此类分析模型的适用性，风电场涡轮机轮毂高度与大气边界层高度相比应该很小，与风电场的水平延伸和到最近的表面不均匀性的距离相比应该非常小。还讨论了包括最近发现的阻塞效应的可能性和选项。