Casing pressure measurements and Stereoscopic Particle-Image Velocimetry (SPIV) measurements are used together to characterize the behavior of the rotor tip leakage flow at both the design and near-stall conditions in a low-speed multistage axial compressor. A three-dimensional Navier-Stokes solver is also performed for the multistage compressor and the prediction of tip leakage flow is compared with SPIV data and casing dynamic static pressure data. During the experiment 10 high-frequency Kulite transducers are mounted in the outer casing of the rotor 3 to investigate the complex flow near the compressor casing and Fourier analyses of the dynamic static pressure on the casing of the rotor 3 are carried out to investigate the tip leakage flow characteristics. At the same time, the two CCD cameras are arranged at the same side of the laser light sheet, which is suitable for investigating unsteady tip leakage flow in the multistage axial compressor. The SPIV measurements identify that the tip leakage flow exists in the rotor passage. The influence of tip leakage flow leads to the existence of low axial velocity region in the rotor passage and the alternating regions of positive and negative radial velocity indicates the emergence of tip leakage vortex (TLV). The trajectory of the tip leakage vortex moves from the suction surface toward the pressure surface of adjacent blade, which is aligned close to the rotor at the design point (DP). However, the tip leakage vortex becomes unstable and breaks down at the near-stall point (NS), making the vortex trajectory move upstream in the rotor passage and causing a large blockage in the middle of the passage.

壳体压力测量和立体粒子图像测速 (SPIV) 测量一起用于表征低速多级轴流压缩机的设计条件和近失速条件下转子尖端泄漏流的行为。还对多级压缩机进行了三维纳维-斯托克斯求解器，并将叶尖泄漏流量的预测与SPIV数据和套管动态静压数据进行了比较。实验期间，在转子3的外壳中安装了10个高频Kulite换能器，以研究压缩机壳体附近的复杂流动，并对转子3的壳体上的动态静压进行傅里叶分析，以研究尖端泄漏流量特性。同时，两个CCD相机布置在激光光片的同一侧，适合研究多级轴流压气机中的非定常叶尖泄漏流。SPIV 测量表明转子通道中存在叶尖泄漏流。叶尖泄漏流的影响导致转子通道中存在低轴向速度区域，正负径向速度交替区域表明叶尖泄漏涡流（TLV）的出现。叶尖泄漏涡的轨迹从吸力面向相邻叶片的压力面移动，该压力面在设计点 (DP) 处靠近转子对齐。然而，叶尖泄漏涡变得不稳定，并在近失速点（NS）处破裂，使得涡轨迹在转子通道中向上游移动，并在通道中部造成大的堵塞。