Numerical and Experimental Investigations of a Compressor Cascade Flow With Secondary Air Removal

The paper presents numerical and experimental results for a low speed compressor cascade with bleed air removal at the endwall. The aerofoil design is representative for a stator blade in a modern high pressure compressor near the casing wall. Secondary air is commonly supplied by simple bleed geometries downstream of stator rows. The focus of the present investigation was the systematic development of a passage integrated bleed configuration. With the assumption of an invariable bleed mass flow rate it should be designed to provide an advantageous effect on the main flow. Furthermore, a high pressure recovery in the bleed flow was aspired. Steady 3D RANS simulations were performed using the Spalart-Allmaras turbulence model. In both numerical simulations and experiments, an improved performance was found. Beside reduced losses and increased pressure rise, the wake flow downstream of the customized bleed geometry was found to be more homogeneous with decreased deviations due to a favorable influence on the secondary flow.