【作者】 刘楠；

【导师】 廖伟丽；

【作者基本信息】 西安理工大学 ， 水利水电工程， 2008， 硕士

【摘要】 随着风能利用在我国的深入推广,风力机风轮气动性能的预测研究越来越受到重视。为了能比较精确的预测风力机风轮的气动性能,本文利用CFD作为工具,通过求解基于压力修正方法的不可压缩N-S方程来研究水平轴风力机风轮在不同风速及不同转速下气动特性的变化规律。所作的工作及主要结论如下所述:首先,介绍了我国风电产业和风力发电机组的现状和发展趋势,简述了风力机气动性能的研究方法。其次,介绍了风力机相关的一些基本理论,如动量理论、叶素理论、动量-叶素理论并重点介绍了CFD数值模拟方法,包括流动控制方程、湍流模型和控制方程离散求解。然后,选择某上风向水平轴风力机风轮为研究对象进行数值模拟。建立了三维实体模型,确定了计算区域并对计算区域进行了网格划分,应用有限体积法和基于压力修正的simplec方法,采用三种湍流模型计算了不同来流风速情况下风力机风轮的流动性能,并与实验数据进行比较,得到其中模拟精度最高的为k-ωsst湍流模型。数值模拟结果表明本文数值模拟具有一定的可靠性。最后,对风力机叶片展向不同截面内和整个叶片范围内的绕流进行流动分析,研究表明:三维旋转效应引起的失速延迟现象对风力机叶片绕流的影响较大;对风力机分别处于58rpm、72rpm和90rpm转速下的轴功率和功率系数随风速变化的情况进行研究,结果表明:在本文选择的六种风速下,90rpm转速时可以使风力机获得比较令人满意的轴功率和功率系数。更多还原

【Abstract】 With the wide spread of wind power utilization in our country, aerodynamic performance prediction of wind turbine rotor becomes more and more important. In order to accurately predict HAWT rotor performance, aerodynamic characteristics of a horizontal axis wind turbine rotor at different wind speeds and different rotating speeds have been studied in present dissertation by CFD. An incompressible Reynolds Averaged Navier-Stokes solver was used, which bases on pressure correction approach. The main contents and conclusions are as following:Firstly, the current situation of wind power industry and wind turbines in our country was described and a brief description about the methods of wind turbine aerodynamic performance study was presented.Secondly, basic theories about wind turbine were introduced, such as momentum theory, blade element theory and BEM theory. CFD theory was introduced in detail, including flow control equations, turbulent models and the theories on discrete equations.Then, an upwind HAWT rotor was seleted as investigation objective of numerical simulation. A three-dimensional geometry model was built and the computation domain was meshed. Numerical model used in present dissertation bases on finite volume method and simplec algorithm. Three turbulent models were compared, of which k-ωsst turbulent model is the best one. Flow characteristics at different wind speeds were analyzed and compared with experimental data. Good agreement was achieved between the k-ωsst turbulent model simulation and the experimental result.Finally, the flow on whole blade and different spanwise sections were analyzed. Simulation result shows that flow charateristic is influenced seriously by 3D rotational effect, which can result in stall delay. Power and efficiency characteristics of this wind turbine vs wind speed were studied at rotating speeds of 58rpm, 72rpm and 90rpm. The result shows that higher aerodynamic performance can be achieved at the rotating speed of 90rpm for six wind speeds studied in present dissertation.更多还原