Tip Clearance Flow in a Compressor Rotor Passage at Design and Off-Design Conditions

Abstract

The flow field in the tip clearance region of a compressor rotor at an off-design condition is reported in this paper. The earlier data at the design condition have also been reinterpreted and correlated with the blade and the flow parameters. The measurements inside the rotor tip region are acquired using a miniature hot-wire sensor of “V” configuration. The instantaneous velocity data are analyzed by the ensemble-averaging technique to derive the blade-to-blade velocity field at various axial and radial locations between the rotor tip and the casing. The flow and the blade pressure data at the design condition are compared with the data at the off-design condition (lower blade loading). In addition to a reduction in the leakage velocities, its chordwise variation is also altered substantially at the lower blade loading.