Two-scale momentum theory for very large wind farms
Two-scale momentum theory for very large wind farms
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超大型风电场的二尺度动量理论
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
T. Nishino
中科院分区：
文献类型：
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作者：
T. Nishino
提出了一种新的理论方法来预测超大型风电场的实际效率上限。新理论表明，理想超大型风电场中理想涡轮机的效率主要取决于无量纲参数λ/CF0，其中λ是转子扫掠面积与土地面积的比率(对于每台涡轮机)，CF0是在建设风电场之前观察到的自然摩擦系数。当X/Cf趋于零时，新理论又回到了经典的驱动盘理论，得到了众所周知的Betz极限。当λ/CF0增大到较大值时，每个涡轮机的最大功率系数减小，而农场的归一化功率密度逐渐增加到上限。文中还给出了一个无限大风电场的CFD分析，该风电场的阵列配置为“对齐”和“错位”，以验证新理论中使用的一个关键假设。
A new theoretical approach is proposed to predict a practical upper limit to the efficiency of a very large wind farm. The new theory suggests that the efficiency of ideal turbines in an ideal very large wind farm depends primarily on a non-dimensional parameter λ/Cf0, where λ is the ratio of the rotor swept area to the land area (for each turbine) and Cf0 is a natural friction coefficient observed before constructing the farm. When X/Cf approaches to zero, the new theory goes back to the classical actuator disc theory, yielding the well-known Betz limit. When λ/Cf0 increases to a large value, the maximum power coefficient of each turbine reduces whilst a normalised power density of the farm increases asymptotically to an upper limit. A CFD analysis of an infinitely large wind farm with ‘aligned’ and ‘displaced’ array configurations is also presented to validate a key assumption used in the new theory.