中文摘要：

利用线式互相关粒子图像测速（PIV）系统和轴编码器锁相技术，测量了不同尖速比下旋转水平轴风力机叶尖处的流场，获得了风轮叶尖处的瞬时速度场，并通过Tecplot软件处理得到了相应的时均速度场、速度云图及流线图．对瞬时图分析可知：在同一尖速比下，叶尖涡的出现使速度亏损值增加，风轮功率下降；在高尖速比下，流场中叶尖涡出现频率较高，有明显的旋涡结构出现，但随着尖速比的减小，叶尖涡出现的频率降低，只有形成的趋势，在尖速比λ=4的工况下，没有完整的涡出现．通过分析时均图表明：随着尖速比的增加，上游空气通过叶尖后的动能损失增大，叶尖尾迹区内的速度亏损范围增大．

英文摘要：

The flow fields at blade-tip of the rotating horizontal-axis wind turbine （HAWT） under different tip speed ratios were measured using the linear correlation particle image velocimetry（PIV） system and axis-coder positioning period sampling technology. The instantaneous velocity field was obtained, and relevant time mean velocity field, velocity contour and streamlines were obtained by using Tecplot software. Analysis on the instantaneous figures indicates that, with the appearance of the blade-tip vortex, the velocity loss increases, and the power of the wind impeller decreases at the same tip speed ratio. At high tip speed ratio, the appearance frequency of the blade-tip vortex is high, and obvious vortex structure appears. But with the decrease of the tip speed ratio, the appearance frequency of the blade-tip vortex decreases, and only the tendency exists for vortex forming. At tip speed ratio of 4, no complete vortex appears. Analysis on the time mean figures indicates that, with the increase of tip speed ratio, the kinetic energy loss of upstream air through blade-tip increases, and the range of velocity loss in wake of blade-tip increases.