To investigate the impact of total pressure loss and inlet distortion caused by curved engine intake on the stability of compressors during real flight conditions, a coupled computational study was carried out on a real intake and a 1.5-stage transonic axial-flow compressor from a specific gas turboshaft engine using full annulus unsteady 3D computational fluid dynamics (CFD) simulations. By varying Mach number and inflow angle of attack, the influence of real flight conditions on the aerodynamic parameters at the compressor inlet and compressor performance are studied. The results indicate that, compared with ground stationary design conditions, the distorted intensity at aerodynamic interface plane (AIP) interface increases under real flight conditions, the total pressure distorted index has doubled and swirl distorted index increases threefold, the distortion continues to propagate and develop within the compressor. Unsteady computational results reveal that the distorted inflow caused by real flight conditions alters the interface between shock waves and tip leakage flow, induces unsteady variations in the rotor flow field, and consequently impacts the stability of compressor. In addition, the negative effect of swirl distortion on flow field is greater than that of total pressure distortion. This study is expected to be helpful in evaluating factors contributing to compressor destabilization and provide a reference for the integrated design of intake ducts and compressors with ground stationary conditions.
Fan et al. (Sat,) studied this question.