Measurements of rotor stalling in a matched and a mismatched multistage compressor

Abstract

This paper presents the results from a set of experiments on stall inception in multistage axial flow compressors. The experiments were tailored to investigate phenomena having a wide range of time and length scales. This range of scales was motivated by two previously observed paths to stall. Parametric changes such as tip clearance, inlet distortion and mismatch were carried out to demonstrate the importance of component coupling in the stall inception process. Evidence is presented for the importance of the local compressor characteristic in determining where and when the initiation of the stall inception process will occur. Although the stall inception process may begin as a localized event, its growth into rotating stall is governed by the environment established by the coupling of the various compression system components. Finally, the tip flow field, specifically the rotor tip leakage jet, is shown to be a key feature in the stall inception process.