Flow field measurements above wing of high-lift aircraft configuration at high Reynolds number

Abstract

Of special interest for the optimization of high-lift systems for starting and landing transport aircraft is the flow field above the wing that is directly impacted by the flow around the nacelle/pylon and the edges of retracted slats. To suppress flow separations, streaks are placed on the nacelle to generate vortices possessing a high amount of kinetic energy at high angles of attack. It is crucial to investigate the complex interaction between the streak vortices and the boundary layer of the wing at the correct Reynolds number. Therefore, flow field measurements has been conduced on a half-wing model of a real aircraft in the European Transonic Wind tunnel (ETW). To take account for the specific conditions existing inside this cryogenic wind tunnel facility a especially developed cryo-PIV system has been applied.