PIV技术在前体非对称涡结构研究中的应用

介绍了北航D4风洞PIV系统的布置及具体实验方案，在此基础上实现了PIV技术在前体非对称涡流动结构研究中的应用。在迎角50°、Re=0．14×10°～0．55×106时，对旋成体X／D=2和3．35截面流动结构进行研究。结果表明，随着胁数的增加截面上流动结构存在从非对称二涡向三涡发展的趋势；在亚临界区，旋涡对非对称压力分布的影响起主要作用；在临界起始发展区及临界区，边界层流动状态及其分离形态对非对称压力分布的影响起主要作用；前体非对称涡沿轴向由二涡向三涡的发展状态在临界起始发展区比亚临界区将向更上游的位置发生。

PIV technology and its application in the investigation of asymmetric vortices structure over forebody

In this paper, the arrangement of PIV system and the experiment scheme in D4 wind tunnel in BUAA were presented. The application of PIV technology in the investigation of asymmetric vortices structure over forebody was also presented. The flow structures of sections X/D = 2 and 3.35 were investigated at 50° angle of attack and Re = 0. 14 × 106 - 0.55 × 106. Experiment results showed that with the increase of Reynolds number the flow structures on the sections had the trend of developing from two vortices to three vortices. In the sub-critical regime,the vortices had the main effect on the asymmetry of pressure distribution. In the initial critical and critical regime, the flow condition and the separation shape of the boundary layer had the main effect on the asymmetry of pressure distribution. In the initial critical regime, the trend of developing from two vortices to three vortices along the model axis happened more upriver than the trend in the sub-critical regime.