Improving Ice Accretion Simulation Through the use of CFD

In order to correctly predict an aircraft ice accretion, the ice prediction tool shall be capable of predicting the aerodynamic characteristics of both clean and iced airfoil and be able to predict the shape of the ice accreted on both wind tunnel and actual aircraft geometries. This requires the analysis tool to be able to correctly predict the local airflow on aerodynamic surfaces that have large separation regions, as well as local water impingement, freezing, convective cooling and evaporation rates. The capability of different RANS models to predict the aerodynamic degradation of an iced airfoil is evaluated. Additionally it is tested whether a more detailed simulation, that includes a more sophisticated computational model (a Navier-Stokes CFD code instead of a panel method code) which keeps the wing lift constant over the simulated time period, rather than using a constant wing angle-of-attack, would influence the resultant ice shape for a typical aircraft performing a holding, in a severe ice environment.