MEASUREMENTS OF FLOW STRUCTURES IN A TURBINE CASCADE USING A SPIV

This paper presents the application of the stereoscopic particle-image velocimetry (SPIV) in a Low-speed Turbine Cascade. In the measurements, a pair of frame-straddling-based CCD cameras was configured at different sides of the laser light sheet, and the appropriate tracing particles were used. It is demonstrated that the measured flow field with such a configuration are very important for the investigations of unsteady flow structures of the tip leakage vortex (TLV) and secondary flows inside the turbine cascade. And this configuration is also easy to use in turbine cascade. The instantaneous snapshots, time-averaged flow field and statistic flow field inside the turbine cascade passage were obtained. The representative flow structures, such as the TLV, the passage vortex and the induced vortex, can also be depicted clearly. Moreover, according to this investigation, some useful proposals are presented for the application of SPIV in the turbine cascade.