A Study on the Control of Wing Surface Flow through Main Wing Boss Fairing and Nacelle Vortex Generators

Transport aircraft often adopt a high-lift configuration that incorporates multi-stage lift-enhancing devices such as leading-edge slats and trailing-edge flaps to augment lift. However, the design of suspended nacelles beneath the wings complicates the airflow characteristics around these devices, thereby increasing the likelihood of premature stall on the upper surface of the wings. This article deeply analyzes the flow mechanisms of two-dimensional multi-segment wings and three-dimensional high-lift devices, and elaborates on their design methods. At the same time, the article also discusses how to effectively control the flow separation on the upper surface of the wing by rectifying the leading edge of the wing and installing vortex generators on the nacelle, thereby improving the overall performance of the aircraft. The application of a fairing on the protruding tab can improve the airflow at the junction of the leading-edge slat and the suspended nacelle, resulting in an approximate 3% increase in the maximum lift coefficient. The implementation of a wing leading edge fairing can enhance the flow dynamics at the intersection of the flap and the pylon, leading to a notable improvement of around 3% in the maximum lift coefficient. Moreover, the incorporation of vortex generators on the shorter span can significantly augment the maximum lift coefficient by 20% while also delaying the stall angle by an impressive 8 degrees.