【作者】 沈昕；

【导师】 杜朝辉；

【作者基本信息】 上海交通大学 ， 航空宇航推进理论与工程， 2007， 硕士

【摘要】 风能作为一种取之不尽、用之不竭的新型能源具有良好的应用前景和开发潜力。我国的风能资源比较丰富,大力发展风电事业符合我国确立的可持续性发展的战略要求。近年来,将空气动力学的理论应用于改进水平轴风力机设计的研究逐步深入,计算机技术和计算流体力学的发展为提高水平轴风力机研究水平提供了有利条件。水平轴风力机的气动性能预测是风力机研究者面临的最困难的工作之一,也是风力机设计的必要步骤。其预测准确性直接影响到风力机的工作寿命以及经济成本。自然界风的不稳定性及叶片流场的三维特性在一定程度上都增加了风力机气动性能预测的难度。本文的主要工作如下:1.采用基于涡系理论的模型建立刚性圆柱尾迹和预定尾迹模型的升力面法预测程序,对无偏航情况的风力机性能进行了预测。使用预定尾迹模型可以更为准确地预测风力机的性能。2.在预测模型中采用Du-Selig静态失速延迟模型来修正两维失速问题,解决了联合试验转子在7~10m/s风速下单独使用预定尾迹模型的升力面法对输出功率的低估问题。通过不同来流风速下在不同叶高位置的攻角、升力系数和阻力系数的比较,确定在中间叶高附近是流动分离最早发生的区域,也是静态失速延迟模型主要修正的区域。3.使用自由尾迹模型对有无偏航情况下的风力机性能进行预测。使用该模型可以更准确地预测无偏航工况下的风力机性能,并且可以直接预测偏航工况下风力机的气动性能。通过和实验值的比较发现基于自由尾迹的升力面法的预测精度基本可以满足工程需要。更多还原

【Abstract】 The development of wind energy in the world is flourishing because it is a kind of absolutely clean and renewable energy. There is considerable wind energy resource in China and the development of wind energy is fully agreed with the durative development strategy. Although there are exciting new development, particularly in the improvement of CFD and theory of aerodynamics, the aerodynamic performance prediction is one of many remained challenges.The performance prediction is necessary to determine the capability of the rotor and the cost of the wind turbine. However the aerodynamics of a wind turbine is extremely complicated, due to the 3-D rotating effects of the blade, effects of an upstream wake for a support structure like tower, complicated environmental effects such as atmospheric turbulence, direction and spatial variations in wind shear, et al.Main contents of this thesis are described as the following:1. Based on the vortex theory, lifting surface method is used to establish wind turbine performance prediction model with rigid cylinder wake model, prescribed wake model and free-wake method. The performance prediction result from the prescribed wake model is better than that from the rigid cylinder wake model.2. Du-Selig stall delay model is used to improve the performance prediction accuracy at the 7~10m/s inflow wind speed. It is found that the large attack angle occurs at the region at the blade mid-span.3. Under unyawed flow condition, the main character of geometry of the tip vortex can be captured with the free-wake model. More accurate performance result of the wind turbine than using prescribed wake model can be acquired.4. Under yawed flow condition, the tip vortex has a skew angle with the wind direction. The attack angle at 57% blade span changes like a更多还原