Active control of rotating stall in a three-stage axial compressor

摘要

Stall inception in a three-stage axial compressor has been suppressed over a range of previously unstable operating points through the feedback of velocity perturbations to the inlet flow field. Perturbations were generated using 12 individually actuated guide vanes at the compressor inlet. The operating range was extended by 7.8% to a slope of 0.9 on the pressure rise characteristic. Over this range data describing the compressor's pressure rise and torque were collected. Flow field measurements upstream of the compressor revealed the excitation of spatial harmonics in the annular flow field before stall inception. With or without feedback, a spatial mode was observed to grow into a stall cell without a discontinuity of amplitude or position. The decrease in the stall inception mass flow as a result of damping the critical spatial mode indicated the importance of spatial modes in the stall inception process in this compressor.