LAUSR

This contribution presents experimental results of a two-element high-lift airfoil in a disturbed inflow. Permanent disturbances are generated by the wakes of two static airfoils located upstream of the research airfoil, one of which is a planar wake by an infinite airfoil and the other is a longitudinal vortex emanating from a finite wing. The disturbances induce spanwise gradients into the flow. The disturbed flow field is measured by Particle Image Velocimetry. The interaction of the disturbed flow field with the high-lift airfoil is investigated by means of static surface pressure close to the airfoil’s leading- and trailing-edge, as well as surface hotfilm measurements and oil flow visualizations on the high-lift flap. For small and moderate incidences the airfoil is mainly influenced by the circulation induced by the disturbances, which affect the effective flow angles. Local effects that result from the turbulence in the airfoil-wake and the induced transverse velocity of the disturbances are likewise considered. At high angle of attack, the prevailing stall conditions with strong variations in spanwise direction are discussed.