Characteristics of the Tip Leakage Vortex in a Low-Speed Axial Compressor

摘要

The flowfields in the tip region of the rotor passage are investigated from a large-scale low-speed axial compressor test at both the design and near-stall conditions by using stereoscopic particle image velocimetry. The characteristics of the tip leakage vortex (TLV) are analyzed based on the variations of its trajectory, concentration, size, streamwise velocity, and the blockage effect, which are extracted from both the ensemble- and conditional-averaged results. According to the ensemble-averaged performance of the TLV, its evolution procedures can be divided into several distinct flow phases. As the flow phase of the TLV changes, its mean flow characteristics also change accordingly. The TLV is inherently unsteady and features unsteady behaviors of vortex wandering, splitting, and breakdown, which have profound effects to its mean flow characteristics.