Two-scale momentum theory for time-dependent modelling of large wind farms
Two-scale momentum theory for time-dependent modelling of large wind farms
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大型风电场瞬态建模的二尺度动量理论
DOI：
10.1017/jfm.2020.252
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发表时间：
2019
影响因子：
3.7
通讯作者：
T. Dunstan
中科院分区：
文献类型：
--
作者：
T. Nishino;T. Dunstan
本文提出了一种基于动量守恒定律的理论来定义和分析大型风电场的空气动力学问题。该理论将问题分成两个子问题：一个是“外部”(或农场尺度)问题，它是一个与时间相关的问题，它考虑大气边界层(ABL)的大尺度运动，以评估某一时刻大气边界层(ABL)底部阻力可用的动量大小；一个“内部”(或涡轮机尺度)问题，它是一个准稳态问题(根据ABL的大尺度运动)，它描述了ABL底部阻力分解为风力涡轮机阻力和陆地/海面摩擦。这两个子问题通过一个称为“农场风速降低系数”或“农场感应系数”的无量纲参数相互耦合，由此推导出一个简单的解析式，可以使用从这两个子问题获得的信息迭代求解。这种一般形式的耦合允许我们将本理论用于每个尺度的各种流动模型，例如用于外部问题的数值天气预报模型和用于内部问题的计算流体动力学模型。该理论首先针对简化的风电场情况提出，然后讨论如何将该理论应用于实际问题，例如，如何估计在给定环境条件下给定的大型风电场由于所谓的“风电场阻塞效应”而造成的功率损失。
This paper presents a theory based on the law of momentum conservation to define and help analyse the problem of large wind farm aerodynamics. The theory splits the problem into two subproblems; namely an ‘external’ (or farm-scale) problem, which is a time-dependent problem considering large-scale motions of the atmospheric boundary layer (ABL) to assess the amount of momentum available to the bottom resistance of the ABL at a certain time; and an ‘internal’ (or turbine-scale) problem, which is a quasi-steady (in terms of large-scale motions of the ABL) problem describing the breakdown of the bottom resistance of the ABL into wind turbine drag and land/sea surface friction. The two subproblems are coupled to each other through a non-dimensional parameter called ‘farm wind-speed reduction factor’ or ‘farm induction factor,’ for which a simple analytic equation is derived that can be solved iteratively using information obtained from both subproblems. This general form of coupling allows us to use the present theory with various types of flow models for each scale, such as a numerical weather prediction model for the external problem and a computational fluid dynamics model for the internal problem. The theory is presented for a simplified wind farm situation first, followed by a discussion on how the theory can be applied (in an approximate manner) to real-world problems; for example, how to estimate the power loss due to the so-called ‘wind farm blockage effect’ for a given large wind farm under given environmental conditions.
在 Cray 机器上进行高度可扩展的云建模的现场数据分析
DOI：
10.1002/cpe.4331
发表时间：
2017
期刊：
Practice and Experience
影响因子：
--
作者：
Brown N
通讯作者：
Brown N