Study of the flow field near the AOA sensor of an A320 aircraft

Abstract

The flow field near the angle of attack (AOA) sensors of an Airbus A320 aircraft was modeled numerically, simulating low speed and high-speed cruise conditions. Because of concerns about the effect of a cargo door installation on the performance of these sensors, an imperfection caused by the gap between the door and the fuselage was modeled. Consequently, by comparing the two computational models, the differences in the flow field could be studied. The main objectives of this study were to correlate the local streamline angle with the airplane geometrical AOA, and to quantify the effect of such surface imperfections due to the cargo door installation. At this initial phase, the study was limited to zero sideslip flight conditions. Computed results indicate that the AOA sensor height is on the order of the local boundary layer thickness, but nearby flow direction is unaffected by the door groove perturbation. The main conclusion therefore is that the cargo door groove has no significant effect on the flow direction near the AOA sensors and on the local boundary layer thickness.