基于致动盘模型的风力机尾流流场数值模拟

发布时间：2018-03-27 22:19

本文选题：风力机　切入点：发电量　出处：《华北电力大学》2014年硕士论文

【摘要】：风力机尾流效应是影响风电场发电量最常见的问题,尤其是目前我国风电场越来越多,单台风力机功率越来越大,深入研究尾流的特点和规律是具有现实意义的。常用的CFD方法占用的计算资源较多,花费时间较长,很难应用于多台风力机的风场计算,所以,本文使用致动盘法,用致动盘代替风轮,在方程中加入体积动量源来虚拟叶片的效应,避免了对实际叶片的模拟,减小了计算量,节省了时间,适合工程应用。本文分两步对致动盘代替风轮进行研究。首先研究了诱导因子均匀分布的致动盘法,即在整块致动盘上,轴向诱导因子是定值,并且不考虑切向诱导因子。选取两个不同的诱导因子值进行对比计算,对两者压力和尾流流场进行对比分析,其计算结果与实验数据基本相符,但是受轮毂和叶根部分影响,2.5D处数值有少量偏差。然后研究可变诱导因子的致动盘模型,即使用叶素动量理论求得轴向诱导因子和切向诱导因子值,并将其沿径向分布于致动盘上,定性分析其尾流流场,并与诱导因子的分布趋势相比较,确定模型的可靠性。最后,应用该方法,分析串列风力机在不同间距下,下游风力机所受到的上游尾流的影响。
[Abstract]:The effect of wind turbine tail flow is the most common problem affecting the generation of electricity in wind farms, especially in China, where more and more wind farms are produced and the power of a single wind turbine is increasing. It is of practical significance to study the characteristics and laws of wake flow in depth. The commonly used CFD method takes up more computing resources and takes a long time, so it is difficult to be applied to the wind field calculation of many wind turbines. Therefore, in this paper, the actuator disk method is used to replace the wind turbine. The effect of virtual blade with volume momentum source is added to the equation, which avoids the simulation of the actual blade, reduces the amount of calculation, saves time, and is suitable for engineering application. In this paper, a two-step study is carried out on the drive disk instead of the wind wheel. Firstly, the method of uniform distribution of the inductive factor is studied, that is, the axial inductive factor is a definite value on the whole disk. And the tangential induction factor is not taken into account. Two different inductive factors are selected for comparison and calculation, and the pressure and wake flow field are compared and analyzed. The calculated results are in good agreement with the experimental data. However, there is a small deviation at 2.5 D due to the influence of the hub and the blade root. Then, the actuator disk model of variable induction factor is studied, that is, the axial and tangential induction factors are obtained by using the blade element momentum theory, and they are distributed along the radial direction to analyze the wake flow field qualitatively. Compared with the distribution trend of induction factor, the reliability of the model is determined. Finally, the influence of upstream wake on the downstream wind turbine under different spacing is analyzed by using this method.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM315

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