This paper describes work conducted as part of an experimental and numerical study of leakage effects by numerous Research and Industrial partners. For clarity it is presented in two parts. Part 1 presents measurements of tip-clearance flow for a 3rd stage rotor embedded in a four stage low-speed research compressor. The measurements are innovative and comprise measurements in the rotor relative frame of reference and 3D Laser time-of-flight Anemometry. Both techniques are relevant for improved understanding of multistage compressor flow dynamics and consequently, validated multistage CFD simulations.
In part 2 of this paper (see Politis et al 1997b) it is shown that downstream of the rotor passage the location and size of a tip-clearance vortex, identified from both independent measurement techniques in Part 1, is in good agreement with 3D solutions of the Navier-Stokes equations modelling this compressor. These 3D numerical solutions reveal the tip-clearance flow structure using a multiblock grid technique.
