Numerical Investigation On High-lift Airfoils In SLD Icing Environment And The Aerodynamic Performance Ansys

The supercooled large droplet (SLD) icing, which often occurs in thelower attitude where the high-lift configuration works, is beyond theenvelope described in the Appendix C of FAR25. However, the mechanismof SLD icing is not clear and the icing characteristics on the high-liftconfiguration still lack of sufficient study currently. A numericalinvestigation in SLD icing conditions is performed for multi-element airfoils.Droplets trajectories, icing simulation on three-element airfoils have beenverified respectively. With this numerical method, sensitive studies areapplied on high-lift profile of certain model in SLD conditions withvariations of parameters including the median volume diameter (MVD),Liquid Water Content (LWC), ambient temperature and airspeed. Thenaerodynamic performance analyses are performed on simulated ice shapes to evaluate the icing safety of aircraft. According to the predicted consequence,it shows that the characteristic drop diameter change will result incompletely different ice shapes, especially for flap, while other parametersreflect the normal ice growth rates. The aerodynamic performance analysesshows that the aerodynamic separation resulting from iced shapes occurs inadvance, the stall attack of angle and the coefficient of lift will be decreased.The ice shapes under SLD icing environment are more dangerous.