A Modified Circumferentially Averaged Method for Compressor Performance under Inlet Distortion

Inlet distortion detrimentally affects the aerodynamic performance and lessens the stability of compressors, and has received considerable attention. The need to accurately estimate its effect on the performance and stability of compressor as early as possible in a pre-design cycle is emphasized herein. This work presents a modified circumferential average through flow method (CAM) based on parallel compressor (PC) theory for compressor performance and stability analysis under inlet distortion. The PC approach classically considers independent circumferential flow zones evolving through a compressor, with the same outlet static pressure. In the present work, this theory has been modified in order to create a parametric outlet static pressure boundary condition. It enables us to deal with an upstream flow distortion map, and the meridian plane flow field can then be calculated in order to update the corresponding compressor performance. The model is applied in a compressor which has been tested for its performance characteristics under uniform inlet conditions. Utilizing the new model, the stability and performance of the compressor under inlet distortion can be estimated.