中文摘要：

在直流式低速风洞中，应用二维PIV系统，对水平轴风力机叶片周围流场进行了测试，揭示了在设计风速下，气流以相对风速流过叶片时，叶片周围流场的分布规律。在各个测试截面内，吸力面气流速度均高于相对风速，压力面气流速度均低于相对风速；气流沿叶片表面流动味发生分离时，叶片吸力面速度最大区域位于截面翼型最大厚度处；发生分离时，越靠近叶根位置，吸力面速度最大区域越向下游迁移，且分离点越靠近翼型前缘：叶尖部位存在从翼型后缘看为逆时针旋转的涡流，呈螺旋状向下游传播。PIV测试分析为叶片最佳空气动力学特性的设计提供了指导，并取得了大空间单烟雾发生器直流风洞的PIV实验经验。

英文摘要：

In a low speed blow down wind tunnel, the flow field around a blade of HAWT （Hori- zontal axis wind turbine） was measured using PIV （Particle Image Velocimetry） system as air flow- ing over the blade at the relative wind speed. In every measuring section, the air speed is higher than the relative wind speed on the suction surface and lower than the relative wind speed on the pressure surface. The maximal speed region on suction surface exceeds the maximal thickness of airfoil when the air is not separated from blade surface. After the air is separated from blade sur- face, the more the position reaches to the blade root, the more the maximal speed region moves downstream arid the more the separation point moves to the leading edge. There is a counter-clock- wise vortex at blade tip when look at it from trailing edge. PIV test analysis can provide direction for optimal blades aerodynamics design, and practical experience has been obtained on using large- space single-fogger generator in the wind tunnel for PIV experiment.