A novel secondary flow deviation model based on corner flow mechanism for throughflow analysis

Modern compressors evolve toward higher-loading and lower-aspect-ratio designs, significantly amplifying the impact of secondary flows on flow deviation angles. However, existing secondary flow deviation models struggle to mechanistically resolve corner flow physics, which is the primary contributor to this deviation. This study develops a physics-based secondary flow deviation model for throughflow analysis that explicitly predicts both the magnitude and spanwise distribution by rigorously accounting for corner flow mechanisms. The new model decouples secondary flow deviation into two physically distinct components: (1) corner vortex-induced and (2) end wall boundary layer (EWBL) induced deviations. Each component is characterized through dedicated momentum-based submodels that respectively describe corner vortex evolution dynamics and EWBL migration processes. Comprehensive validation using numerical and experimental data from subsonic linear cascades demonstrates an over 70% reduction in root mean square error (RMSE) compared to the conventional approach. Moreover, the model successfully captures abrupt deviation increases during corner separation-to-stall transitions and reveals complex interactions between hub and shroud corner flows. This work establishes a fundamentally sound framework for secondary flow deviation prediction, substantially improving throughflow analysis accuracy in challenging corner flow regimes and providing reliable insights for preliminary compressor design optimization.