Influence of dynamic behavior of supercooled large droplets on airfoil icing

Supercooled large droplets (SLD) represent one of the most hazardous flight conditions. The unique dynamic behavior of large droplets, including deformation, fragmentation, splash, and rebound, poses challenges for accurately assessing SLD icing using traditional icing calculation methods. In this study, the Navier-Stokes method was employed to solve the flow field, the Euler method was used to calculate droplet impact, and the Shallow Water model was utilized to simulate ice accretion. The credibility of the proposed methodology was verified by comparing the results with NASA experimental data. The findings demonstrate that the dynamic behavior of SLD significantly influences icing and ice formation. Specifically, deformation and fragmentation alter the trajectory and impact range of droplets, reducing the droplet impact limit, resulting in a 2.83% and 2.13% decrease in upper and lower icing limits, respectively. Splashing reduces the collection efficiency of droplets near the stagnation point, resulting in an 8.09% reduction in leading-edge ice accretion. Rebound considerably lowers the droplet impact limit, leading to a 30.69% and 20.01% decrease in upper and lower icing limits, respectively. Moreover, the re-entry of secondary droplets into the flow field following rebound increases the upper and lower icing limits by 6.14% and 3.71%, respectively. Furthermore, the aerodynamic performance of the ice-contaminated airfoil significantly deteriorates compared to a clean airfoil. At the same angle of attack, the lift decreases, the drag increases, and the aerodynamic efficiency decreases. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.