Investigation on predicting the stall limit of compressor at low rotating speed

In order to realize fast and accurate prediction of the stall limit of compressor, a study on predicting the stall limit of compressor at low rotating speed is conducted with throughflow calculation and maximum static pressure rise coefficient. The calculated stall limit of 30%–60% design speed for four axial compressors is compared with the experimental results. The results show that the blade loading increases significantly from the shroud to the hub at the near stall condition of the compressors with low inlet hub-tip ratio. If the maximum static pressure rise coefficient calculated with the spanwise averaged parameters from the throughflow analysis is used to determine the stall limit. The stall limit predicted by the throughflow calculation has a large deviation with the experimental result. The maximum deviation of near stall total pressure ratio and near stall mass flow reach 15% and 30% respectively. In this paper the spanwise variation of the static pressure rise coefficient is taken into account to define the stall limit prediction method. At a particular spanwise position, the maximum effective static pressure rise coefficient is calculated with the parameters at the blade section determined by the throughflow streamline. Taking the maximum static pressure rise coefficient at the low spanwise position with high blade loading as the stall criterion, the stall limit of the compressors can be predicted well with throughflow calculation compared to the experimental results. The maximum deviation of near stall total pressure ratio and near stall mass flow is respectively lower than 2% and 3%.