Prediction of Compressor Performance in Rotating Stall

Abstract

A correlation is presented for predicting the performance characteristics of single and multistage axial compressors in rotating stall. The correlation is derived from new measurements of stalled compressor performance which have been obtained using a series of different compressor builds. In these experiments the compressor design parameters were systematically varied so that the influence of each could be clearly seen. It is shown that the stall cell blockage is an important parameter for correlating the flow regimes in stall, and hence the overall compressor performance. The resulting correlation, which has been developed based on a heuristic model of the stalled flow, can be applied to predict whether a given compressor will exhibit full-span or part-span stall, as well as the extent of the stall-unstall hysteresis loop. In particular, it is shown that as the number of stages and/or the design value of axial velocity parameter increases, the trend is toward both full-span stall and large hysteresis loops.