风力机叶尖涡尾迹结构PIV测量研究

空气动力研究与发展中心低速空气动力研究所依托工程型大风洞（实验段直径3.2 m），采用高分辨率CCD相机（4 008像素×2 672像素），针对旋转状态下的风力机叶片尾流开展大视场（单个观测区域达到570 mm×380 mm）PIV(particle image velocimetry)测量，以NREL UAE Phase Ⅵ风力机叶片1/8缩比模型为实验对象，获取了叶尖涡产生、发展的流动数据，为研究风力机叶尖涡结构和流动机理研究提供重要的基础数据．观测结果表明，叶尖涡从后缘脱落后首先有一个短时间的向内运动，然后随着尾流的膨胀向外运动，其涡强度则先是短时间内降低，然后随着涡的卷起而增强，从而形成一个强大的叶尖涡．在实验观察范围内叶尖涡在来流方向的迁移规律近似线性．

PIV Measurements of Tip Vortex Wake Structure of a Wind Turbine

Large-view flow field measurements using PIV(particle image velocimetry)technique with high resolution CCD cameras on a rotating 1/8 scale blade model of NREL UAE PhaseⅥwind turbine were conducted in the engineering-oriented ?3.2 m wind tunnel at the Low Speed Aerodynamics Institute of China Aerodynamics Research and Development Center.The motivation behind the tests was to establish the database of the initiation and development of the tip vortex in order to investigate the flow structure and mechanism of the wind turbine.The results showed that the tip vortex firstly moved inward for a very short time and then moved outward with the wake expansion while its vorticity decreased with time after just trailed from the trailing edge of the blade tip and then increased continuously with rapid roll-up to form a strong tip vortex.The measurements also indicated that the downstream movement of the tip vortex was nearly linear in the very near wake under the test condition.