Effect of Casing Treatment on the Type of Instability Inception in a High-Speed Axial Compressor

Abstract

Flow instability phenomena limit the operating range of compressors, so the study of instability inceptions has received a lot of attention. Casing treatment is a commonly used technique to extend the operating range. In order to study the effect of casing treatment on the instability inception and its evolution, experimental investigations are carried out on a transonic axial flow compressor operating at a low rotor speed. By comparing the dynamic instability signals with and without casing treatment, it can be found that the existence of casing treatment can alter the type of instability inception and restrain its development. Based on the discussion of the simulation results, the radial redistribution of blade loading caused by the casing treatment is considered to be the main reason for the change of instability inception.