3 component LDV for near wall measurements on a multi-element high lift airfoil configuration

Abstract

Flow field investigations in the near wall region of a high lift wing configuration have been performed by means of a 3D laser-Doppler velocimeter with a working distance of 3.5 m. The measurements were conducted on a 1:7.5 AIRBUS A321 model of Daimler-Benz Deutsche Aerospace (DASA) in the closed 6 m/spl times/8 m test section of the Deutsch-Niederlandischer Windkanal (DNW), The Netherlands. Due to motions and vibrations of the model with amplitudes in the range of a factor of 15 greater than the required spatial resolution, a simultaneous acquisition of the translatoric parameters was indispensable to convert the obtained velocity data measured in a wind tunnel fixed co-ordinate system into a model fixed co-ordinate system. As a result of the applied procedure velocity, turbulence, and shear stress data also close to the wall could be measured very accurately even though the model could not be held fixed in space. Valuable results on the three dimensionality of the flow field and the behaviour and the structure of the separation bubble in the wing shroud have been obtained.