Numerical Study of the Circumferential Fluctuations in Swept Compressor Cascades

This paper presents comparative numerical studies to analyze the inlet flow and circumferential fluctuation(CF) source terms in compressor cascades. Forward swept cascades with different sweep angles and straight cascade were calculated numerically by a computational fluid dynamics(CFD) package to get the required three-dimensional(3D) flow parameters. A dimension reduction method was introduced and an in-house code for data reduction was conducted to obtain a circumferentially averaged flow field. The results show that different sweep angle and nominal incidence angle will change the magnitude and distribution of the CF source terms at inlet thus altering the inlet flow field. The Mach number(Ma) could also change the inlet CF source terms under the same swept angle. The trends of radial migration and the blade loading would increase with the growing of the inlet Ma.