Investigation of Factors Affecting Iced-Airfoil Aerodynamics

A summary of the effects the ice-accretion geometry, size, and location; the airfoil geometry; and the ight Reynolds number on iced-airfo ilaero dynamics, based on the ndings of the recent University of Illinois investig ations, is presented. Four airfoilswere tested withsimula tedglaze-ice hornandspanwiseridgeice. Increasing the ice-shapeheight generally resultedin more severe performance degradation.The exception wa swhentheice shape was located at theleading edgeof the airfoil, whereincrea sed ice-shapeheight didnotsigni cantly degradeperformance.Varying the leading-edge radius of glaze-ice horn did not have a large effect on a irfoil perfo rmance. The variations in the geometry of the simulated ridge ice had some effect on airfo il aerody namics, with (of the shapes tested) the half-round shape having a signi cantly higher maximum lift. Iced-airfoil aerodynamicswere relatively insensitive to Reynolds number variations. Large differences in iced-airfoil aerody namics were observed between different airfoil geometries. The ndings showed that an airfo il’s sensitivity to ridge-ice accretions (which usually forms between 10 and 20% chord) was largely dependent on its load distribution. The airfoil that was very front-loaded, with large leading-edge suction, had the most severe perfo rmance degradation due to this type of ice a ccretion.