时间步进自由尾迹方法建模及水平轴风力机气动性能分析_博士学位论文.doc

时间步进自由尾迹方法建模及 水平轴风力机气动性能分析 重庆大学学位论文重庆大学学院 Horizontal Axis Wind Turbine Aerodynamic Performance Investigation with A Time-Marching Free Vortex Wake Model A Thesis Submitted to Chongqing University in Partial Fulfillment of the Requirement for the Degree of Doctor of Engineering By Zhou Wenping Supervised by Prof. Tang Shengli Major：Power Engineering and Engineering Thermophsics College of Power Engineering of Chongqing University, Chongqing, China October 2011 摘 要 气动性能预测Ⅵ风力机在轴流和偏航时的尾迹形状和气动性能进行计算，并与文献实验数据进行比较，结果表明：当风力机处于来流风速较小的轴流工况时，尾迹涡不能被输运到下游较远的地方，使得涡-涡干扰较大，桨尖涡的位置及气动载荷的计算误差较大，随着风速的增大，涡的诱导影响减小，计算值与实验值吻合非常好；稳定偏航时，本文模型能够在不添加任何修正模型的情况下较好地预测偏航引起的尾迹结构的非对称性及周期载荷，从而验证了模型的有效性。 ⑥对风力机处于变桨、稳态风剪切、极端动态来流等非定常风况时的气动性能计算表明：复杂来流时，转子尾迹会出现瞬时畸变，同时桨叶上的涡在脱落并向下游传输的过程中，需要一定的时间才能使尾迹从一个流态变成另一个流态，导致诱导速度的时间滞后响应，本文的自由尾迹模型能够较好的体现这种滞后响应对气动性能的影响，具有明显的优势。在此基础上，得到了一些有意义的结论，为风力机的优化设计及选型提供支持。 关键词：，，，， ABSTRACT During Horizontal Axis Wind Turbine (HAWT)’s design and checking process, aerodynamic performance prediction is very important. Calculation of blades’ aerodynamic performance after the design of aerodynamic shape is an evaluation for design results; conversely, aerodynamic performance results can be used as feedback for the amendment of aerodynamic shape of blades. But the load prediction is very difficult, because HAWT operates in complex natural environment, such as wind shear, variation of wind speed and direction, tower influence and so on. Currently, wind turbine designers rely on safety factors to compensate for the effect of unknown loads acting on the turbine, which results in components that are overdesigned because precise load level and load paths are unknown. In order to advance wind turbine technology, the forces acting on the turbine structure must by accurately characterized. When HAWT is rotating, wake vortices are released from blades’ trailing edge, form an inboard vortex sheet and rolled up to strong tip vortex. The strength of the vortex is determined by the geometry a