Sensitivity analysis for stall inception of transonic rotor based on meridional flow

This paper presents a sensitivity analysis method for analyzing the key factors affecting the stability problem of the transonic compressors. The adjoint method is integrated into the meridional stability model, a linear stability prediction model utilized to analyze the flow stability problem of the compressor, and the sensitivity analysis method is further developed for the flow stability problem of the compressor. The study selects the NASA Rotor37, a transonic compressor, as the research object to verify the proposed method and explore the sensitive factors leading to the stall inception. The results of sensitivity analysis to both the flow parameters and the external source terms reveal that the stall inception is sensitive to the base flow field at the rotor tip and the stability margin of the compressor can be enhanced by improving the flow field at this region. Physical explanations are presented and discussed to correlate the three-dimensional flow field to the results obtained via the employed analysis method, which shows that flow structures and characteristics near the end-wall region, especially the tip leakage flow or the tip leakage vortex and its interaction with the shock wave, contribute to the stall inception.