Aerodynamic prediction and roughness implementation toward ice accretion simulation

Ice accretion in aircraft leads to significant separation and surface roughness. Therefore, the simulation of icing is highly intricate and challenging. The aerodynamic prediction of an iced wing requires an accurate turbulence model. In this paper, a modified transition model for the Reynolds-averaged Navier-Stokes equation is developed. The model is implemented using a linear eddy viscosity transition model as a baseline. It is modified to accurately predict the flow separation and simulate the influence of roughness. Different cases are numerically tested based on the modified model, including two types of iced airfoils (glaze ice and rime ice) and two rough geometries. The results indicate that the model demonstrates engineering accuracy in terms of the flow separation and aerodynamic coefficient prediction. Moreover, this model could be adapted for a wide range of ice shapes. In addition, the present model is capable of accounting for the influence of surface roughness, leading to significant improvements in heat transfer coefficients that match the experimental data well.