Active control of rotating stall in a low-speed centrifugal compressor

This paper addresses rotating stall control in centrifugal compressors, pre senting the results of on experiment directed at the suppression of stall i n the Purdue Low-Speed Centrifugal Research compressor. The control techniq ue uses a phase-controlled inlet distortion generated by an array of 12 air -injection ports located in the compressor inlet endwall. The active contro l of first-mode (one-fell) rotating stall was successfully demonstrated. In the cases investigated, the stall control system provided only slight incr eases in stall margin. However, the control system demonstrated an ability to restore system stability to the compressor H-hen exhibiting a de,eloped stall condition.