An experimental investigation of end-wall flowfield of a compressor rotor

An investigation of the end-wall flowfield in a single-stage compressor rotor is presented. The main emphasis of the investigation was to measure the flowfield in detail in a low-speed compressor rotor. A single-channel laser Doppler velocimeter (LDV) was used to measure the flowfield in the tip clearance region. The investigation was carried out for two tip clearances (clearance/chord = 1.78 and 3.4 percent). In addition, the relative stagnation pressure field, corresponding to a tip clearance of 1.78 percent, was also measured using a Kiel probe to supplement the LDV measurement. The measurements showed that the leakage flow originated at about one-quarter-chord location. Past quarter-chord location, the inteaction between the leakage flow and the annulus-wall boundary layer resulted in unconventional and skewed boundary layer profiles. Inside the rotor passage, the leakage flow effects were augmented by the leakage flow emanating from the entire blade chord length. Downstream of the rotor, the interaction between the leakage flow and the rotor wake resulted in rapid wake decay at higher radii. The leakage flow which was intense at larger clearance might have rapidly smoothed the irregularities downstream of the rotor.