Prediction of Inlet Distortion Induced Axial Compressor Flow Field Instability in Mid-Air Refueling

The propagation of strong distortion at inlet of an axial compressor is investigated by applying the critical distortion line and the integral method. The practical applications, such as flaming of leakage fuel during mid-air refueling process, are implemented to show the details of the numerical methodology used in analysis of the axial flow compressor behavior and the propagation of inlet distortion. From the viewpoint of compressor efficiency, the propagation of inlet flow distortion is further described by a compressor critical performance and its critical characteristic. The simulated results present a useful physical insight to the significant effects of inlet parameters on the distortion extension, velocity, and compressor characteristics. The distortion level, the size of distortion area, and the incidence angle at compressor inlet, and the rotor blade speed are found to be the major parameters affecting the mass flow rate of engine.