大型海上风力机尾迹区域风场分析

Numerical analysis for the wake zone of large offshore wind turbine

随着世界范围内海上风电场的不断兴起及海上风电场设计规模的日趋庞大,大型海上风力机尾迹区域风场特征的研究对于海上风电场的优化布局有着重要的指导意义。本文基于三维Navier-Stocks控制方程和适用于旋转流场分析的RNGk-ε湍流模型,采用滑移网格技术对美国可再生能源实验室(NREL)的5 MW海上风力机的性能及其尾迹区域的风场特征进行了较为系统的数值模拟。通过将不同风速下风力机输出功率的数值结果与NREL的设计参考数据进行对比,三维数值模型的有效性得到了很好地验证。此外,在此基础上进一步研究了大型海上风力机额定风速下及不同风轮转速下尾迹区域平均风速的分布特征,并得到了一系列具有参考价值的重要结论。

With the rising of the offshore wind farm all over the world,the rated design power and scale of offshore wind farms are tending to be larger and larger.Therefore,the study on the wake effect of the large offshore wind turbine（OWT） is of great importance to the optimal layout of offshore wind farms.In this work,based on Navier-Stocks equations and the RNG k-ε turbulence model,which is very suitable for the rotational fluid flow,the three-dimensional numerical simulations for the aerodynamic performance of the NREL 5MW offshore wind turbine blades and its wake effects on the downstream flow have been done by using advanced sliding mesh technique.The validation of the three-dimensional numerical model has been verified by comparing the numerical output power results under different inlet wind speeds with the correlative NREL design data.On the basis of this model,the distribution characters of the mean velocity in the OWT wake zone under rated inlet wind speed and different rotational speeds have been investigated.Consequently,a series of conclusions have been obtained,which are of great importance for large offshore wind farms.