Stalled Flow Performance for Axial Compressors: II — Rotating Stall Characteristic

Abstract

This paper describes a study of stalled flow performance of multistage compressors. The study is focused on the performance in rotating stall, in particular, the impact on stall inception and stall recovery. It is argued that the recovery point measured in post-stall compressor tests results from a compression system instability, rather than from an unstable rotating stall flow. If so, recoverability from rotating stall may be improved by altering system parameters. Furthermore, the full-span rotating stall characteristic is extrapolated beyond the measured recovery point. On this basis, the compressor stall point is viewed as a bifurcation, where a change in flow mode exists, perhaps analogous to the critical point in the axial compression of thin shells. An application for the extended rotating stall characteristic is in a model of transient compression system behavior.