平面扩压叶栅流场犘犐犞与三孔尾迹探针对比测试研究

针对PIV技术在暂冲式高亚声速平面叶栅流场中遇到的示踪粒子投放问题，通过采用高压雾化式粒子发生器以及安装在稳定段前的撒播器，有效地使示踪粒子均匀地与主流混合，并成功开展了某扩压平面叶栅叶片槽道及出口尾迹可视化测量，获得了零迎角、进口马赫数0．2～0．8状态下的二维速度矢量场。为了验证PIV在叶栅流场测试结果的可靠性，在相同工况下，将PIV测量结果分别与数值计算结果和三孔尾迹探针测量结果进行了对比分析。结果表明：采用PIV技术测得的叶栅中截面二维速度矢量场合理地反映了叶片槽道及尾迹的流动结构，与数值模拟结果较为接近；PIV与三孔楔形尾迹探针在叶栅出口尾迹的测量所获得的气流速度和主流区的出口气流角重合性较好；尾迹分离区的出口气流角重合性略差，主要原因是尾迹区气流角超出了探针校准范围，这也说明了PIV测试技术优势。本文提出的PIV测量技术也可用于连续式叶栅风洞中。

Comparative study between PIV and three-hole wake probe measurements in the compressor plane cascade flow field

The tracer particles selecting and sowing was very important in PIV technology applied to blow-down and high subsonic plane cascade flow field measurement.In this paper,tracer partides flow was effectively mixed with the main flow by using high pressure atomized particle generator and broadcaster installed in front of the steady pressure section,and we successfully obtained 2-D velocity fields of a compressor cascade channel and wake at zero incidence angle and inlet Mach number from 0 .2 to 0 .8 .In order to validate reliability of PIV results in the cascade flow field,the PIV results were compared with the results of the numerical simulation and three hole wake probe in the same aerodynamic conditions.The results indicated that 2-D velocity vector field acquired by the PIV was closer to the numerical simulation results,and reasonably reflected the flow structure of the blade passage;the PIV data got good agreement with the three hole wake probe data in the aspect of the velocity magnitude and flow angle at mainstream area of the cascade outlet.But the coincidence of flow angle at wake separation area was slightly bad. The main reason was that the flow angle in this area was beyond the scope of probe calibration. In addition,in order to obtain accurate PIV measuring results,it was very important to avoid contamination of the tracer particles to the window during the measurement.PIV measurement technique proposed in this paper could also be used for continuous cascade wind tunnel.