Investigation of Ice Accretion Characteristics and Post-Icing Flow Field Improvement Methods for Hybrid-Wing-Body Aircraft

Abstract Ice accretion is a critical factor that compromises the flight safety of hybrid wing body (HWB) aircraft. This study aims to characterize the icing behavior of an HWB configuration and, on this basis, to further investigate the effectiveness of a leading-edge droop strategy in enhancing the icing tolerance of iced airfoils. An Eulerian droplet approach coupled with a shallow-water icing model was employed to numerically predict glaze-ice accretion on the HWB aircraft surface. Based on the resulting ice geometry, the Reynolds-averaged Navier–Stokes (RANS) method was applied to systematically examine the aerodynamic responses of iced airfoils under different leading-edge droop angles. The numerical results demonstrate that leading-edge droop can effectively suppress flow separation on the upper surface of iced airfoils, albeit at the expense of intensified separation on the lower surface. For cases characterized by extensive upper-surface separation, leading-edge droop markedly improves the aerodynamic performance of iced airfoils. In contrast, when upper-surface separation is limited while lower-surface separation is dominant, this strategy fails to alleviate the overall flow separation and may even exacerbate it, leading to further deterioration of lift and drag characteristics.