Determining the effect of endwall boundary layer suction in a large scale subsonic compressor cascade

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An arrangement of suction slots was installed in the Naval Postgraduate School's subsonic cascade wind tunnel. The aim was to improve flow two-dimensionality to enable flow separation of the installed controlled- diffusion blades at high incidence. The slots were located 17.25 inches upstream of the test section. Pressure and laser Doppler velocimetry measurements were made, for a Reynolds number of 711000 and an inlet flow angle of 44.4 deg, upstream and downstream of the test section to determine the effects of varying suction. The set of baseline inlet flow field measurements was to be used for comparison purposes in future tunnel modifications. The results showed that the tunnel endwall boundary layers were asymmetric for the baseline configuration. Uniform suction was not achieved in both the pitchwise and spanwise directions. However, the axial velocity ratio was reduced by 1.9% and the blade loading increased slightly with increased suction.