一种新修正的风电机组尾流分析模型

基于尾流区线性膨胀、径向风速损失呈高斯分布的假设,在BP模型基础上建立一种新修正的风电机组尾流分析模型。该模型针对BP模型无法对近尾流区进行分析的问题,基于质量守恒原理求解近尾流区速度损失分布;通过大涡模拟数据拟合,对BP模型中速度损失标准差方程进行修正,提升了模型在不同地表粗糙度下的计算精度。采用大涡模拟数据对多种工程尾流模型的计算结果进行比较。结果表明,相比于Jensen、Frandsen和BP模型,该模型能更好地预测全尾流范围的径向速度分布,并且具有更高的计算精度。

A NEW MODIFIED ANALYTICAL MODEL FOR WIND-TURBINE WAKES

Based on the BP model, a new modified analytical model is proposed to predict the wind velocity distribution of the wind turbine wake. The model is derived by assuming a linear expansion for the wake region and a Gaussian distribution for the velocity deficit in the wake. Based on the conservation of mass, the velocity deficit distribution in the near-wake regions is calculated by using this proposed model, which cannot be solved by the BP model. The expression of the normalized standard deviation of the Gaussian-like velocity deficit profiles in the BP model is modified by extrapolating the large eddy simulation （LES） data of real-scale wind-turbine wakes, which improves the prediction accuracy of the wind velocity distribution of the wind turbine wake on flat surfaces with different aerodynamic roughness. The velocity deficit profiles in the wake predicted by the proposed model and other common analytical models are compared to the LES data. The results show that the velocity deficit in the wake predicted by this model is in good agreement with the LES data and is more accurate than that of the results calculated by the Jensen, Frandsen and BP models.