Effect of Non-Axisymmetric End Wall on a Highly Loaded Compressor Cascade in Multi-Conditions

As an effective method to influence end wall flow field, non-axisymmetric profiled end wall can improve the aerodynamic performance of compressor cascades. For a highly loaded low pressure compressor cascade, called V103, the study found the optimal non-axisymmetric profiled end wall decreases total pressure loss coefficient by 4.57%, 5.48% and 3.04% under incidences of −3°, 0°, and 3°, respectively, compared with those of the planar end wall. The optimal non-axisymmetric profiled end wall changes the structure of secondary flow in hub region, generating a corner vortex near suction surface, inhibiting the development of the passage vortex towards suction surface and reducing flow separation. When the inlet Mach numbers are 0.62 and 0.72, the total pressure loss coefficient decreases by 3.19% and 4.58% for optimal non-axisymmetric profiled end wall compared with those of the planar end wall. Though optimal non-axisymmetric profiled end wall increases total pressure loss near hub region in blade passage under different inlet Mach numbers, the peak value and region of high loss coefficient above 10% span in blade passage significantly decrease. In addition, different incidences affect the secondary flow streamlines and vortex structure near the cascade hub region, however, different inlet Mach numbers hardly change the secondary flow streamlines and vortex structure. In short, the optimal non-axisymmetric profiled end wall shows better aerodynamic performance than the planar end wall for the highly loaded compressor cascade in multi-conditions.