In this paper, wake steering is applied to multirotor turbines to determine whether it has the potential to reduce wind plant wake losses. Through application of rotor yaw to multirotor turbines, a new degree of freedom is introduced to wind farm control such that wakes can be expanded, channelled or redirected to improve inflow conditions for downstream turbines. Five different yaw configurations are investigated (including a baseline case) by employing large-eddy simulations (LES) to generate a detailed representation of the velocity field downwind of a multirotor wind turbine. Two lower-fidelity models from single-rotor yaw studies (curled-wake model and analytical Gaussian wake model) are extended to the multirotor case, and their results are compared with the LES data. For each model, the wake is analysed primarily by examining wake cross-sections at different downwind distances. Further quantitative analysis is carried out through characterisations of wake centroids and widths over a range of streamwise locations and through a brief analysis of power production. Most significantly, it is shown that rotor yaw can have a considerable impact on both the distribution and magnitude of the wake velocity deficit, leading to power gains for downstream turbines. The lower-fidelity models show small deviation from the LES results for specific configurations; however, both are able to reasonably capture the wake trends over a large streamwise range.

中文翻译：

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多旋翼风力涡轮机的尾流转向

在本文中，尾流转向应用于多旋翼涡轮机，以确定它是否有可能减少风力发电厂的尾流损失。通过将转子偏航应用于多转子涡轮机，风电场控制引入了新的自由度，以便可以扩展、引导或重定向尾流，以改善下游涡轮机的流入条件。通过采用大涡模拟 (LES) 来生成多转子风力涡轮机顺风的速度场的详细表示，研究了五种不同的偏航配置（包括基线情况）。来自单旋翼偏航研究的两个低保真模型（卷曲尾流模型和分析高斯尾流模型）扩展到多旋翼情况，并将它们的结果与 LES 数据进行比较。对于每个模型，尾流的分析主要是通过检查不同顺风距离处的尾流横截面。通过对一系列流向位置上的尾流质心和宽度的表征以及对电力生产的简要分析，进行了进一步的定量分析。最重要的是，研究表明转子偏航会对尾流速度赤字的分布和大小产生相当大的影响，从而导致下游涡轮机的功率增加。对于特定配置，低保真度模型与 LES 结果的偏差很小；然而，两者都能够合理地捕捉大流向范围内的尾流趋势。通过对一系列流向位置上的尾流质心和宽度的表征以及对电力生产的简要分析，进行了进一步的定量分析。最重要的是，研究表明转子偏航会对尾流速度赤字的分布和大小产生相当大的影响，从而导致下游涡轮机的功率增加。对于特定配置，低保真度模型与 LES 结果的偏差很小；然而，两者都能够合理地捕捉大流向范围内的尾流趋势。通过对一系列流向位置上的尾流质心和宽度的表征以及对电力生产的简要分析，进行了进一步的定量分析。最重要的是，研究表明转子偏航会对尾流速度赤字的分布和大小产生相当大的影响，从而导致下游涡轮机的功率增加。对于特定配置，低保真度模型与 LES 结果的偏差很小；然而，两者都能够合理地捕捉大流向范围内的尾流趋势。对于特定配置，低保真度模型与 LES 结果的偏差很小；然而，两者都能够合理地捕捉大流向范围内的尾流趋势。对于特定配置，低保真度模型与 LES 结果的偏差很小；然而，两者都能够合理地捕捉大流向范围内的尾流趋势。