【作者】 何兰芳；

【导师】 高伟；

【作者基本信息】 华中科技大学 ， 热能工程， 2007， 硕士

【摘要】 风力机是风力发电系统中的关键设备,其动力特性直接影响风力发电系统的效率。为减少风力机叶端漩涡,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,根据风能充分利用和实现分布式风力发电的需求,本文以某200W水平轴小型风力发电机为原始模型,应用基于N-S方程的3维稳态隐式解法、SST k-ω湍流模型、二阶迎风格式离散方法、压力-速度耦合的SIMPLE算法等技术手段,利用计算流体软件FLUENT对扭转叶片风力机的动力性能进行了数值模拟分析与研究。本文以原始风力机模型的叶根最大截面扭转角度为基准(0°),分别研究叶尖截面扭转角度γ=+2°,+1°,0°,-1°,-2°,-4°,…,-20°(“+”表示顺时针扭转,“-”表示逆时针扭转,叶根至叶尖的中间截面扭转角度用线性插值法确定)情况下,同一风速不同尖速比、同一尖速比不同风速下的风力机动力特性。得出了与风力机理论相吻合的叶片扭转角度对风力机动力放大的模拟结果和变化规律,验证了研究方法的正确性。在此基础上,选择不同风速下具有最大动力放大能力的扭转叶片(扭转-13°)风力机和原始模型进行对比,通过计算同一尖速比不同风速下的功率变化情况,证明该叶片在不同风速下皆有一定的动力放大作用。随后对原始风力机和叶片扭转-13°风力机叶片的压力特性、速度特性进行了对比分析,获得了风力机叶片扭转后叶端流场的变化。本文的研究再现了叶片扭转改变其气动性能和改变风力机的功率、压力、速度特性的客观规律,对小型风力发电机的叶片设计有着指导意义。本文的研究方法与成果可为其它类型的风力机叶片研究所参鉴。更多还原

【Abstract】 Wind turbine is a critical equipment in wind power generation system, whose dynamic property impacts the efficiency of wind power generation system directly. This paper is a research which the blade of horizontal axis wind turbines is twisted. In order to decrease the vortex on the blade tip and the flow loss and bring the power augmentation, and is that the more wind energy is converted to the electric energy, based on using wind power fully and the need to achieve the aim of the distributional wind power generation, this paper take Nanjing tianneng FDP1.3-200W horizontal axis wind turbine as primitive model , apply technology method based on N-S equation, 3-D, steady, implicit solve, turbulence model of k-ωSST, discretization of SECOND ORDER UPWIND and pressure-velocity coupling of typical SIMPLE scheme, simulate dynamic magnification performance of horizontal axis wind turbine and horizontal axis wind turbine by software of CFD----FLUENT.In this paper ,we take the maximal cross section of blade root as a datum( 0°), to research dynamic property of wind turbine under the same wind speed and a range of tip speed ratio or the same wind speed and a range of wind speed, in the condition of different torsion angle of blade tip cross sectionγ= 2°, 1°, 0°, -1°, -2°, -4°,……, -,20°("+" expresses the clockwise torsion, "-" expresses the anticlockwise torsion, the centre cross section torsion angle is computed by linearity interpolation law) . At last , we arrive at a conclusion that wind torsion change regularity of power augmentation of a wind turbine. It accord with the change tendency of the wind turbine theory. Then compare the models of the torsion blade of maximal power amplification and primitive blade, compute the power change condition over the same tip speed ratio and a range of wind speed. The results shows twisting blade have the augmentation action surely. Subsequently the pressure performance and velocity performance of the wind turbine with the blade being twisted are compared with the primitive wind turbine, and we gained the change of the blade tip of the wind turbine with the blade being twisted. Thereby we analyze and disclosure the dynamic augmentation principle of the wind turbine with the blade being twisted.The research of this paper show that the twisted blade change the aerodynamic characteristics and the power, pressure, velocity performance of wind turbine, which is the rule. This has a guide meaning to the blade design of miniature wind turbine. And the research method and conclusion can be used by other kind of wind turbine also.更多还原