Sensitivity Analysis for Flow Stability of Axial Compressor Based on Meridional Flow

Abstract

A sensitivity analysis method for flow stability of axial compressors based on meridional flow is proposed and employed to reveal the sensitive region of stability in the present article. The meridional stability model that transforms the stability problem into an eigenvalue problem enables flow stability to be quantitatively expressed by system eigenvalues. Using the eigenvalue representing the developing characteristics of the perturbations as the targeted parameter and incorporating the adjoint method and the induced boundary conditions, the sensitivity analysis method for the stability problem of the compressor based on meridional flow is established to identify sensitive regions in the flow field. In this study, a low-speed compressor stage at Beihang University, named TA36, is analyzed. The stability prediction model accurately predicts the stall margin and the sensitivity analysis of the base flow parameters reveals that the onset of the rotating stall is particularly sensitive to the blade tip region of the rotor. Meanwhile, the sensitivity analysis of the external source terms shows that applying specific control to the flow field near the tip of the blade can benefit the stall margin of the compressor. The theoretical method proposed in this work effectively identifies the positions of stability sensitivity, which provides valuable insights into understanding the unstable regions and mechanisms of stall inception in axial compressors. The sensitivity analysis to the external source term can guide the design of the flow control methods.