Aerodynamic Prediction of Iced Airfoils Based on Modified Three-Equation Turbulence Model

Abstract

Ice formation on a wing poses a threat to aircraft safety because it changes the effective shape of the wing and considerably deteriorates the aerodynamic performance. The performance prediction of an iced airfoil requires an accurate turbulence model. In this Paper, a three-equation turbulence model for the Reynolds-averaged Navier–Stokes equation is developed to determine the stall behavior of iced airfoils. The model is implemented using a linear eddy viscosity transition model as a baseline and is modified to appropriately simulate complex flow phenomena such as laminar separation, shear layer transition, and turbulent reattachment. The model also takes the nonequilibrium characteristics of turbulence into account. Different airfoils, including clean airfoils and three types of iced airfoils (horn ice, streamwise ice, and spanwise-ridge ice), are numerically tested. The results indicate that the present model demonstrates engineering accuracy in terms of the stall behavior prediction and can be adapted in a wide range of ice shapes. The relative errors of the predicted maximum lift coefficients of the iced airfoils are about 5% of the experimental values.