Numerical simulation of inlet total pressure distortion on a two-stage high-speed axial fan

Abstract

Inlet total pressure distortion is a critical factor affecting aero engines' performance and stability. Steady calculations are conducted for a two-stage fan under uniform inlet conditions. Full annular unsteady simulations of an inserted baffle distortion generator coupled with a two-stage fan are conducted under distorted inlet conditions. Numerical calculation results show that the baffle distortion generator mainly contributes to the total pressure distortion in the fan inlet surface. The total pressure distortion induces the total temperature distortion. The transfer and distribution of the two-stage fan's total pressure and temperature distortions are calculated and analyzed. After the airflow goes through the fan, the intensity of total pressure distortion is weakened, the intensity of total temperature distortion is enhanced, and the total temperature and static entropy at the blade tip region after turning out of the corresponding distortion baffle are more significant. The flow field after the baffle shows a symmetrical double vortex structure, which causes the positive and negative pre-swirl distribution of airflow angle and lower axial velocity.