Numerical Simulations on a Transonic Axial-Flow Compressor Rotor Under Clean and Distorted Inflows

The effects of circumferential distortions in inlet total pressure on the flow field in a low-aspect-ratio, high-speed, high-pressure-ratio, transonic compressor rotor are investigated in this paper. The flow field was studied numerically with and without inlet total pressure distortion. 3-D steady, unsteady numerical simulations have been conducted to determine the effects of circumferential total pressure inlet distortion on a transonic axial-flow compressor rotor. Overall performance (total pressure ratio, adiabatic efficiency and stable operating range) within inlet distortion has been investigated and compared with the results with clean inlet flow: dropped in mass flow, adiabatic efficiency, and decreased in surge margin. Detail analyses of the flow field in the rotor show: Circumferential flow appears at the border of the distorted region, and flows inside to the distorted region. When entering the distortion, the blade passage faces a positive pre-swirl, on the countary, when leavinging the distortion, the blade passage faces a negative pre-swirl, which increases its incidence angle and loading.