Experimental Studies of the Endwall Flow in a Multistage Low-Speed Axial Compressor

Abstract

Detailed flowfield measurements are made in the end-wall region of a four-stage low-speed large-scare axial compressor test rig. Two ten-hole survey boundary layer probes, one four-hole pneumatic probe, and six dynamic pressure probes each bedded with a high-frequence response Kulite sensor, are designed and manufactured to aid the test. Boundary layer region and mainflow region can be clearly distinguished from the boundary layer measurement results. A few parameters, including boundary layer thickness, displace thickness, momentum loss thickness, energy loss thickness and blockage coefficient are calculated based on the measurements. Results from turbulent boundary layer empirical formula of plate are in good agreement with the mesurements, indicating a way of boundary layer effect estimation. The evolution trajectory of TCV is identified evidently by dynamic pressure measurements. The maximum aerodynamic load point on the blade moves from the trailing to the leading edge as flowrate decreases, which leads to the forward movement of the tip clearance vortex inception point.