Numerical analysis of the weight distribution of flow losses in a highly loaded compressor cascade with different incidences

In this study, a method called the “weight distribution of flow losses based on the evolution of vortex structures” is proposed and used to examine the mechanism of flow losses in a highly loaded compressor cascade with different incidences. Numerical simulations, verified against experimental results, were used to obtain the detailed flow field of the cascade. The aerodynamic performance of the cascade with different inlet Mach numbers and incidences is first discussed to determine the initial conditions for the study. Four typical flow conditions are then classified in accordance with the distribution of the limiting streamlines. Following this, the weight distributions of flow losses during the stalling process of the cascades are analyzed based on the evolution of the dominant vortex structures in the cascade passage. The results reveal three dominant vortex structures, the passage vortex (PV), the suction side of the corner vortex (CVS), and the concentrated shedding vortex (CSV). The flow losses are divided into three categories referring to vortex losses, profile losses, and other losses, where the first two are key components. Thus, the weight redistribution of the flow losses is manifested in the weight coefficients ΩB+ and ΩB- for PV, in CVS and CSV, and finally to blend together. Moreover, this transfer motion of the vortex structures is the most important priority of optimization design.