风力机叶尖加小翼动力放大的数值模拟研究

【作者】 贾瑞博；

【导师】 汪建文；

【作者基本信息】 内蒙古工业大学 ， 热能工程， 2005， 硕士

【摘要】 本文研究的风力机叶尖加小翼,是在风力机的叶尖加一个V 型平板或S 型平板,通过改变风力机周围的流场特性,从而改变风力机性能——功率特性,压力、速度特性。目的是减少叶端漩涡,降低叶轮的流动损失,提高风力机的输出功率,将更多的风能转化为电能。本文利用计算流体软件FLUENT 对风力机及其加小翼后的动力放大性能进行了数值模拟,计算是基于N-S 方程,采用3 维稳态隐式解法;湍流模型选择k-ωSST 模型;离散方法为二阶迎风格式;压力-速度耦合采用SIMPLE 算法。模拟了小翼在不同长度和宽度;小翼的长度保持不变时,不同的前缘边和后缘边相对比例系数;小翼的不同的前张角和后张角时风力机稳定运转的状况,并得出了小翼形状和参数对风力机动力放大的变化规律,符合风力机理论变化的趋势。并和实验值进行比较,发现计算值和实验值有一定的误差,但是与实验值的变化趋势相同,表明小翼对风力机确实起到的动力放大的作用。随后对有小翼风力机和无小翼风力机的压力特性、速度特性进行了比较,得到了风力机叶尖加上小翼后,风力机叶端流场的变化。从而分析揭示小翼对风力机动力放大的原理。同时,通过对计算结果与实验值进行比较,可得风力机叶尖加小翼采用的计算模拟方法是正确可行的,为以后小翼的不同安装角和不同风向的模拟计算提供了依据。更多还原

【Abstract】 This paper is a research which a tip vane is a flat of V type and S type which is fitted onthe blade tip. It changes the flow flied characteristic around the wind turbine, thereby,change the performance of the wind turbine----power, pressure and velocity performance.The aim of The wind turbine with a tip vane decrease the vortex on the blade tip and theflow loss and bring the power augmentation, and is that the more wind energy is convertedto the electric energy.In this paper ,we simulate dynamic magnification performance of horizontal axis windturbine and horizontal axis wind turbine with a tip vane by software of CFD----FLUENT.During the calculation, we base on N-S equation, choice 3-D, steady, implicit solver.Turbulence model is k-ωSST. Discretization is SECOND ORDER UPWIND.Pressure-velocity coupling is a typical SIMPLE scheme. We simulate the status of thesteady running wind turbine with the tip vane of the different longitudinal and transyersedimensions, the ratio of the leading edge to the trailing edge length, the front camber angleand back camber angle and endue changing regularity of power augmentation of a windturbine with a tip vane. It accord with the change tendency of the wind turbine theory.After compared with the experiment results, computational results have some error to theexperiment results, but it is same with the variation tendency of the experimental values.The results shows the tip vane have the augmentation action surely. Subsequently thepressure performance and velocity performance of the wind turbine with a tip vane arecompared with the wind turbine with a tip vane, and we gained the change of the blade tipof the wind turbine with the tip vane. Thereby we analyze and disclosure the dynamicaugmentation principle of the wind turbine with the tip vane, Meanwhile, after comparingcomputational results with experiment results, we think the method of calculation andsimulation to the wind turbine with the tip vane is correct. This method is foundation to thecalculation of the different fitting angle and wind direction of the tip vane later.更多还原