Stereoscopic PIV measurement of unsteady flows in an axial compressor stage

Abstract

Stereoscopic particle-image velocimetry (SPIV) measurements are conducted in a Low-speed Large-scale Axial Compressor. During the experiment the two CCD cameras are placed at the different sides of the laser light sheet and it is proved that this configuration is more suitable for the investigation in multi-stage turbomachines. The measured results, including the overall performances of many typical flow structures near the rotor tip region and the phase locked unsteady flows inside the stator passage at both the design and near-stall conditions, are introduced. Some new features of the complicated flow structures, such as the breakdown of the tip leakage vortex, the formation of the compound corner vortex at the rotor suction tip corner, the interactions between the hub stall and the tip separation and the rotor wakes, and the evolutions of the tip corner anti-rotating streamwise vortices inside the stator passage, are revealed.