Characterization of UAV Icing for Different Operating Conditions

This study presents a comprehensive investigation of ice accretion on UAV airfoils using numerical simulations conducted in a two-dimensional framework with a multi-step methodology. The simulations explore the effects of key operating parameters, including velocity, temperature, liquid water content, median volume diameter, and chord length, ranging from a Reynolds number of 10^5 up to 10^6 . The results provide detailed mappings of ice shapes and reveal their dependence on geometrical and environmental parameters. Ice area and thickness are shown to increase with velocity, LWC, and MVD, while decreasing with larger chord lengths due to droplet deflection effects. The transition from rime to glaze ice is dictated by temperature and is further influenced by LWC, MVD, airfoil size and velocity. The formation of horn-like structures is enhanced at higher LWC and MVD, with smaller airfoils exhibiting relatively more prominent horns. These structures moreover directly influence the aerodynamic penalties with a decrease in lift coefficient and an increase in drag due to the separation of the flow. This study offers valuable insights into the mechanisms of ice accretion on UAV airfoils, providing a robust foundation for optimizing UAV performance and safety.