ICING TEST RESULTS ON AN ADVANCED TWO-DIMENSIONAL HIGH-LIFT MULTI- ELEMENT AIRFOIL.

This advanced high lift wing design is based on highlyoptimized gap and overhang settings, which has very littletolerance for contamination. This high sensitivity makes envi-ronmental contamination a very important issue, particularlycontamination due to ice accretions. In order to understand theeffects of ice accretions on the advanced high-lift airfoilaerodynamics, it is essential to test the airfoil under icingconditions that the airfoil would encounter in flight. To date,there has not been any experimental ice shape data availablefor this type of advanced three-element airfoil.Prediction of the flow field around a multi-element airfoilis quite a challenging task due to the complexities associatedwith merging shear layers and multiple separations. Over thepast few years, the viscous flow calculation capability overmulti-element airfoils has seen steady improvement.