An analytical and experimental investigation of the active control of rotating stall in a low speed centrifugal compressor
Abstract
The active control of rotating stall in a low speed centrifugal compressor is investigated. In particular, a study of the applicability of a controlled inlet distortion as a means of adjusting system damping and suppressing a rotating stall condition is performed. As motivation for such a study, results on the stall initiation behavior of the Purdue Low Speed Centrifugal Research Compressor (PLCRC) are presented. These results indicate that the progression into rotating stall is gradual, being characterized by one or more weak spatial pressure waves which grow, over a period of several impeller revolutions, into a large scale rotating stall condition. Based on this evidence, a mathematical model is developed to predict the effectiveness of a controlled inlet distortion as a means of suppressing rotating stall. The results from this model predict that a correcting inlet waveform, when introduced at an optimum phase angle, will be able to extend the range over which the compressor operates stably. Based on the predictions from this mathematical model, an experimental verification of the stalling behavior of the PLCRC under the influence of a controlled inlet distortion is presented. Employing an array of air injection jets as the distortion generator, the control system introduces a phased inlet distortion based on a measured static pressure signal in the inlet. Suppression of one-cell rotating stall is achieved, and the recovery of the compressor from such a condition is also accomplished.
Degree
Ph.D.
Advisors
Fleeter, Purdue University.
Subject Area
Mechanical engineering
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