Effects of endwall boundary layer suction on a counter-rotating compressor

To provide a reference for design and optimization of the aspirate compressor, the performance and detailed flow structure of a counter-rotating compressor were numerically investigated under different suction flow with endwall boundary layer suction through the two rows of suction holes in the casing over the rotor tip. The results show that in multistage environment endwall boundary layer suction can increase compressor stall margin, but the adiabatic efficiency would be adversely affected by excess suction flow. The compressor performs best under 1.6% suction rate while the stall margin increased by 3.8%. Stall is mainly induced by the leakage vortex, and occurs in the tip area of the second row of rotor at first. The suction can weaken the strength of leakage vortex and delay the stall. Since the end wall boundary layer suction increases the flow capacity, the pressure ratio and adiabatic efficiency are increased, meanwhile the flow field in outlet guide vane tip has also been improved.