Abstract: Computational fluid dynamics (CFD) software toolkit FLUENT was used to predict the droplet collection efficiency and anti-icing surface equilibrium temperature on two-dimensional airfoils when the ice protection system was in operation. Collection efficiencies were obtained using the Eulerian multiphase model, implemented through user-defined functions in FLUETN. The surface equilibrium temperature distribution in responding to certain flight condition and the hot-air inlet configuration was predicted by an integrated airfoil leading-edge interior-exterior thermodynamic analysis. Some examples and validation studies were presented. The numerical results are acceptable and consistence with the theory analysis. The presented research work indicates a validity of using FLUENT in studying aircraft anti-icing, including prediction of water collection efficiency and temperature distribution on anti-icing surface, which are useful for future study in design of aircraft hot-air anti-icing system.