Research on the Anti-Distortion Fan Stator Based on Aerodynamic Performance Analysis Under Inlet Distortion

Abstract The influence of inlet distortion on the aerodynamic performance and stability of turbofan engine components is particularly significant, especially in fan systems. This paper addresses inlet distortion in turbofan engines, focusing on the stability of fans operating under distorted conditions. Using a fan-shaped distortion generator, the study simulates distorted inlet flow fields and evaluates the impact of distortion on fan performance across various operating conditions through unsteady numerical simulations. The results reveal that nonuniform total pressure caused by the distortion generator leads to substantial flow losses near the root of the stator under multiple operating conditions. Additionally, while the distortion effect is more concentrated within the stator domain, its circumferential extent remains relatively constant. Based on this analysis of the distorted flow field, the study proposes an anti-distortion strategy for the fan stator to mitigate distortion effects and enhance fan performance. By sequentially adjusting geometric angles, uniform pitch, and alternating pitch, optimal stator configurations were identified (corresponding to the Case-β1k, Case-Ut, and Case-At schemes, respectively). The Case-At scheme, involving multi-level and multi-parameter adjustments, proved most effective in reducing losses and improving flow capacity within the stator passage. Across three operating speeds, the Case-At configuration increased stability margins by 10.31%, 8.31%, and 7.39%, respectively, substantially widening the safety margin under inlet distortion and ensuring reliable performance under challenging conditions.