Linearised CFD Models for Wakes
Linearised CFD Models for Wakes
复制标题
尾流的线性 CFD 模型
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
M. Nielsen
中科院分区：
文献类型：
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作者：
S. Ott;J. Berg;M. Nielsen
这份报告描述了一种快速和相当准确的模型的发展，用于预测off海岸风电场的发电量，其中考虑了尾流ff效应。该模型被实现为一个名为Fuga的Windows应用程序，它可以在批处理模式下运行，也可以作为图形用户界面运行。Fuga是Briefly描述的。该模型基于线性化技术，对线性化技术进行了较详细的描述，推导了线性化的控制方程，并将其写成基于混合谱公式的标准形式。采用了一种新的求解方法来求解该方程，其中包括大量使用查找表来存储中间结果。由于模型的线性，多个涡轮机的多个尾迹可以由一个单独的涡轮机的尾迹构成。通过对来自通用查找表的结果进行快速傅立叶积分变换，进而从傅立叶分量构造这些元素。检验了基于三个不同关闭的三个不同的ff不同模型：根据Horns Rev I和Nysted风电场的off陆上风电场生产数据对模型结果进行了评估，并与陆上涡轮机(NIBE B)的直接尾迹测量进行了比较。对于简单的闭合，得到了与数据非常令人满意的一致。唯一的例外是近尾流，就在旋翼后面，三个线性化模型都失效了。混合长度闭合在所有情况下都低估了尾迹ff效应。E-ε关闭高估了off岸上农场的尾流损失，而它预测陆上事件的尾流太浅太宽。简单闭包的性能明显好于其他两个。来自号角、转速、气象仪桅杆的风速数据被用来进一步验证简单闭合的Fuga结果。最后，以罗兹风电场1号和2号风电场为例说明了风电场之间的相互作用。这份报告描述了一种快速和相当准确的模型的发展，用于预测off海岸风电场的发电量，其中考虑了尾流ff效应。该模型被实现为一个名为Fuga的Windows应用程序，它可以在批处理模式下运行，也可以作为图形用户界面运行。Fuga是Briefly描述的。该模型基于线性化技术，对线性化技术进行了较详细的描述，推导了线性化的控制方程，并将其写成基于混合谱公式的标准形式。采用了一种新的求解方法来求解该方程，其中包括大量使用查找表来存储中间结果。由于模型的线性，多个涡轮机的多个尾迹可以由一个单独的涡轮机的尾迹构成。通过对来自通用查找表的结果进行快速傅立叶积分变换，进而从傅立叶分量构造这些元素。检验了基于三个不同关闭的三个不同的ff不同模型：根据Horns Rev I和Nysted风电场的off陆上风电场生产数据对模型结果进行了评估，并与陆上涡轮机(NIBE B)的直接尾迹测量进行了比较。对于简单的闭合，得到了与数据非常令人满意的一致。唯一的例外是近尾流，就在旋翼后面，三个线性化模型都失效了。混合长度闭合在所有情况下都低估了尾迹ff效应。E-ε关闭高估了off岸上农场的尾流损失，而它预测陆上事件的尾流太浅太宽。简单的闭合效果明显好于进一步使用的号角转速测风仪的其他风速数据
This report describes the development of a fast and reasonably accurate model for the prediction of energy production in offshore wind farms taking wake effects into account. The model has been implemented as a windows application called Fuga which can run in batch mode or as a graphical user interface. Fuga is briefly described. The model is based on alinearization technique which is described in some detail, and linearized, governing equations are derived and written in a standard form based on a mixed–spectral formulation. A new solution method is used to solve the equations which involves intensive use of look–up tables for storage of intermediate results. Due to the linearity of the model, multiple wakes from many turbines can be constructed from the wake of a single, solitary turbine. These are in turn constructed from Fourier components by a fast Fourier integral transform of results derived from generic look–up tables. Three different models, based on three different closures, are examined: Model results are evaluated against offshore wind farm production data from Horns Rev I and the Nysted wind farm, and a comparison with direct wake measurements in an onshore turbine (Nibe B) is also made. A very satisfactory agreement with data is found for the simple closure. The exception is the near wake, just behind the rotor, where all three linearized models fail. The mixing length closure underestimates wake effects in all cases. The E – ε closure overestimates wake losses in the offshore farms while it predicts a too shallow and too wide the wake in the onshore case. The simple closure performs distinctly better than the other two. Wind speed data from the the Horns rev met masts are used to further validate Fuga results with the ’simple’ closure. Finally, Rødsand 1 and 2 are used as an example to illustrate the interaction between wind farms. This report describes the development of a fast and reasonably accurate model for the prediction of energy production in offshore wind farms taking wake effects into account. The model has been implemented as a windows application called Fuga which can run in batch mode or as a graphical user interface. Fuga is briefly described. The model is based on alinearization technique which is described in some detail, and linearized, governing equations are derived and written in a standard form based on a mixed–spectral formulation. A new solution method is used to solve the equations which involves intensive use of look–up tables for storage of intermediate results. Due to the linearity of the model, multiple wakes from many turbines can be constructed from the wake of a single, solitary turbine. These are in turn constructed from Fourier components by a fast Fourier integral transform of results derived from generic look–up tables. Three different models, based on three different closures, are examined: Model results are evaluated against offshore wind farm production data from Horns Rev I and the Nysted wind farm, and a comparison with direct wake measurements in an onshore turbine (Nibe B) is also made. A very satisfactory agreement with data is found for the simple closure. The exception is the near wake, just behind the rotor, where all three linearized models fail. The mixing length closure underestimates wake effects in all cases. The E – ε closure overestimates wake losses in the offshore farms while it predicts a too shallow and too wide the wake in the onshore case. The simple closure performs distinctly better than the other Wind speed data from the the Horns rev met masts used further