水平轴风力机叶片气动性能数值模拟

发布时间：2018-03-29 02:12

本文选题：水平轴风力机　切入点：数值模拟　出处：《重庆大学》2011年硕士论文

【摘要】：准确求解风力机叶片的气动特性对指导风力机安全运行和叶片优化设计具有重要意义。针对准确求解风力机不同工况下气动特性这一问题,本文采用CFD技术对水平轴风力机叶片绕流流场进行了全三维数值模拟,通过对比实验数据验证数值模型的准确性后,对风力机实际运行中叶片表面积灰工况进行模拟,分析比较叶片积灰厚度对气动性能的影响,最后针对在一定比例尺寸的基础上确定风力机实验参数这一问题,提出了一种基于CFD技术以相似理论结合临界雷诺数为约束条件,确定风力机实验参数的方法,以达到节省实验花费,提高风洞实验有效性的目的。研究工作具体内容和结论如下: 本文采用计算流体技术模拟分析了叶片表面积灰厚度对风力机三维气动特性的影响。首先,采用CFD软件包FINETM-TURBO建立风力机的三维模型,模拟叶片表面光滑的情况下该风力机的三维气动特性,并与文献数据进行比较,验证了该模型的有效性。而后针对风力机实际运行中存在叶片积灰情况,模拟了积灰厚度变化对风力机三维气动特性的影响,得到了不同积灰厚度下叶片的压力分布、速度分布的变化。结果表明,叶片表面积灰厚度对风力机叶片气动特性有较大影响:随着积灰厚度的增加,叶片两侧大部分区域风速减小,气流运动无规律性增强,压力面与吸力面压差减小,风力机效率降低。在特定比例尺寸的基础上,确定风力机实验参数是风洞实验至关重要的第一步。基于上述对风力机叶片绕流的三维模拟,本文提出了一种以相似理论结合临界雷诺数为约束条件,确定风力机实验参数的方法。首先计算了实验模型翼型气动特性与雷诺数的变化规律,确定临界雷诺数和实验参数。其次,根据模型和原型的几何尺寸和相应风速,分别仿真模拟了模型和原型,对比分析了压力分布、速度分布和诱导速度分布,结果表明该方法是可行的。
[Abstract]:It is very important to accurately solve the aerodynamic characteristics of wind turbine blades to guide the safe operation of wind turbine and the optimal design of blades. In view of the problem of accurately solving the aerodynamic characteristics of wind turbine under different operating conditions, In this paper, the flow field around the blade of horizontal axis wind turbine is simulated by CFD technology. After the accuracy of the numerical model is verified by comparing the experimental data, the surface area of the blade is simulated in the actual operation of the wind turbine. The influence of blade ash thickness on aerodynamic performance is analyzed and compared. Finally, aiming at the problem of determining the experimental parameters of wind turbine based on a certain proportion of size, a constraint condition based on CFD technology is proposed, which is based on similarity theory and critical Reynolds number. The method of determining the experimental parameters of wind turbine is presented in order to save the experimental cost and improve the effectiveness of wind tunnel experiment. The specific contents and conclusions of the research are as follows:. In this paper, the influence of blade surface area ash thickness on the three-dimensional aerodynamic characteristics of wind turbine is simulated by computational fluid technique. Firstly, the three-dimensional model of wind turbine is established by using CFD software package FINETM-TURBO. When the blade surface is smooth, the three-dimensional aerodynamic characteristics of the wind turbine are simulated, and compared with the data in the literature, the validity of the model is verified. The influence of ash thickness on the three-dimensional aerodynamic characteristics of wind turbine is simulated, and the pressure distribution and velocity distribution of the blade under different ash thickness are obtained. The results show that, The surface area ash thickness of the blade has a great influence on the aerodynamic characteristics of the wind turbine blade. With the increase of the ash deposition thickness, the wind speed decreases in most of the two sides of the blade, the airflow motion is increased irregularly, and the pressure difference between the pressure surface and the suction surface decreases. The efficiency of wind turbine is reduced. On the basis of specific scale, determining the experimental parameters of wind turbine is the first step of wind tunnel experiment. In this paper, a method for determining the experimental parameters of wind turbine based on similarity theory and critical Reynolds number is presented. Firstly, the variation of aerodynamic characteristics and Reynolds number of airfoil in the experimental model is calculated. The critical Reynolds number and experimental parameters are determined. Secondly, according to the geometric size of the model and prototype and the corresponding wind speed, the model and prototype are simulated, and the pressure distribution, velocity distribution and induced velocity distribution are compared and analyzed. The results show that the method is feasible.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TK83

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