Examination of icing mechanism on aircraft wings with numerical methods

In this thesis study, the effects of key parameters such as angle of attack (AoA), liquid water content (LWC), median volumetric diameter (MVD), airspeed and exposure time on the ice formation characteristics as well as the aerodynamic behavior of the NACA 0012 airfoil were investigated using numerical methods. The impact of these parameters was assessed by observing variations in lift and drag values, along with alterations in the shape of the airfoil. To ensure the reliability of the numerical methodology, validation studies were conducted by comparing simulation results for both clean and iced airfoil configurations at various angles of attack with experimental data available in the literature. Analyses of the clean airfoil were performed using ANSYS Fluent, while ice accretion analyses were carried out with the FENSAP-ICE software employing the Spalart-Allmaras turbulence model. Results show that increasing AoA leads to asymmetric ice horn growth and up to 56% lift loss and 625% drag increase at 12°. An increase in liquid water content caused the ice structure to become more irregular and expanded the ice-covered area on both the upper and lower surfaces. As the mean volumetric diameter increased, ice formation spread over a larger area; notably, at an MVD of 50 µm, the highest performance losses were observed despite the maximum ice thickness not occurring at this value. With increasing airspeed, the ice shapes became sharper and more pronounced, and aerodynamic degradation was more significant especially up to speeds of 90 m/s. Finally, longer exposure times caused an increase in both ice thickness and the extent of the ice-covered area, with maximum ice accretion observed after 8 minutes. These findings demonstrate that each parameter significantly affects not only ice geometry but also the aerodynamic performance, which is critical for flight safety.