A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortion

Abstract

A stability model for axial compressors with inlet circumferential distortion is proposed in the present work. Based on the small perturbation theory, the compressor is divided into several inter-blade volumes containing two-dimensional primary flows. The volumes are connected by the actuator disks that includes the work and loss of the blade rows. The final equations are closed with the inlet boundary condition of no input perturbation and outlet boundary condition of no reflected perturbation. The rate of perturbation increase is then determined by the eigenfrequency, and hence the compressor stability is predicted. The model is verified on a low-speed single-stage compressor (TA36) which is numerically simulated and experimentally measured at uniform inlet condition and circumferentially distorted inlet condition. By comparing the stall onsets predicted by this model and classic Hynes-Greitzer (HG) model with experimental results, the reliability and ability of the present model are proved. Finally, a fast stability model to predict the stall onset under inlet circumferential distortion in the design stage is established based on the small perturbation theory and the idea of parallel compressor, which could provide a reference for the compressor stability.