Effect of boundary layer suction control on the corner separation of linear compressor cascade in a droplet-laden flow

This study examines how well boundary layer suction can prevent a highly loadedaxial compressor cascade from cornering out in a droplet-laden flow. SteadyReynolds Averaged Numerical simulations are carried out to examine the impactof various suction slot configurations on the loss coefficient and flowmodifications. It is observed that, when the boundary layer suction is applied alonga portion of the blade span, it minimizes the flow separation locally at that region.Even though this is beneficial, providing a suction slot only a portion of the bladeenhances the flow disturbances. On the other hand, when the suction scheme isemployed on the entire blade span, it considerably increases flow uniformity. Inresponse to the high cross-passage pressure gradient causing persistent three-dimensional corner separation, a combined suction strategy was developed. Thismethod involved the use of a spanwise slot on the suction surface and another onthe endwall, modeled as Flow Extraction and Wall Suction (FEWS). The approachaimed to eliminate separated flow on the blade's suction surface, significantlymitigate 3D corner separation, and improve the uniformity of the flow field. It isobserved that, compared to a dry scenario, a wet environment with a suction flowrate of 1%, significantly lowered the total pressure loss coefficient by 26%.