The design and optimization of 2D and 3D boundary layer suction (BLS) configurations within a highly-loaded diffusion stator was conducted in this paper by using numerical simulations. A detailed analysis was done based on flow mechanism to reveal the reason for reducing flow separation and improving compressor performance by BLS method. The numerical results show that the best BLS position is located at the region a little backward from the separation point in 2D cascade. Further discussion on 3D BLS shows that the combination of blade suction slots along the whole span and slots along streamline at the hub-suction side region achieves the best effect. This compound BLS configuration can effectively control the strong 3D separation flow at the hub-suction side region, which improves the flow condition and leads to a better stage performance.

Key words：