Continuing preliminary data submitted last year, this paper focuses on effect of operation point on the structure of a tip leakage vortex (TLV) in compressor-like settings. Experiments are being performed at the Johns Hopkins University refractive index-matched facility. The transparent acrylic blades of the one and a half stage compressor have the same geometry, but lower aspect ratio as the inlet guide vanes and the first stage of the Low Speed Axial Compressor facility at NASA Glenn. The refractive index of the liquid, an aqueous NaI solution is matched with that of the blades and transparent casing, facilitating unobstructed stereo-PIV measurements. As the flow rate is reduced close to stall conditions, the leakage flow is confined to rotor chordwise sections further towards the leading edge, and the TLV rollup occurs further upstream, and more radially inward. However, as the leakage flow stops in the aft part of the passage, the near-stall TLV migrates faster to the PS side of the next blade. Instantaneous realizations demonstrate that the TLV consists of multiple interlaced vortices and never rolls up into a single structure, but when phased-averaged, it appears as single structure. The circumferential velocity peak is located radially inward of the mean vorticity center. Turbulent kinetic energy (TKE) is high in the TLV center, in the shear layer connecting the suction side (SS) corner to the TLV feeding vorticity into it, as well as in the region of flow separation on the endwall casing where the leakage flow meets the passage flow. The normal and shear Reynolds stress demonstrate high inhomogeneity and anisotropy, with the streamwise velocity fluctuations being the largest contributor to TKE. The dominant inplane contributors to TKE production rate involve contraction in the region of endwall casing separation and near the SS tip corner, and shear production in the shear layer. Fragmentation and rapid growth of the TLV occurs at mid passage, moving upstream with decreasing flow rate.

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