为了实现液力偶合器漩涡流场高精度试验测量，研究粒子图像测速( PIV) 流场试 验测量环节的主要误差来源，分析示踪粒子选择、图像采集策略和流速提取算法对流场测 量精度的影响，提出降减和消除误差的途径与方法． 研究结果表明: 在容积为 2710 mL 的 水介质液力偶合器中投入 1．0g 等效直径为 1．5μm 的 PSP 示踪粒子，图像采集效果好且 粒子浓度满足 PIV 测速要求; 将液力偶合器外壁表面设计为大平面采集区域能够有效地 避免反光现象，并降低离轴角误差和光路折射误差; 采用递归互相关算法，使用自适应查 询区域分析方法，通过 3 次迭代计算，能够更好地提取主流区域上大尺度漩涡流动特征和 局部角隅区域上小尺度涡旋结构特征．

In order to achieve a high-precision experimental measurement of the vortex flow field in a hydrodynamic coupling,main error sources of the internal flow experimental measurement by particle image velocimetry (PIV) technology are investigated,and the influence of the tracer particle selection,the image acquisition strategy and the flow velocity extraction algorithm on the measurement precision of the internal flow field is analyzed.Then,some methods are proposed to reduce and eliminate the errors.The results show that (1) when 1. 0 g PSP tracer particles of an equivalent diameter of 1. 5 μm are put into a 2710 mL water-medium hydrodynamic coupling,the collected flow images are better and the particle concentration can meet the requirements of the PIV speed measure- ment; (2) designing the outer surface of the hydrodynamic coupling as a large plane collection area can effectively avoid the reflective phenomenon and reduce the off-axis angle error and the optical refractive error; and (3) by a- dopting the recursive cross-correlation algorithm and the adaptive interrogation window analysis method to carry out three iterations,the characteristics of both the large-scale vortex flow in a mainstream region and the small-scale vortex structure on local corners can be extracted more effectively.The conclusions will provide a vital reference for the accurate measurement of the vortex flow field in the hydrodynamic coupling．