PIV for complex high-lift-configurations

Abstract

Stereo PIV measurements have been performed in 5 cross - flow planes along the trajectory of the strake wake vortex above the suction surface of the KH3Y wing. The measurement planes were oriented in a model - fixed coordinate system perpendicular to the mean flow direction at α = 0° and tilting with the angle of incidence. A tower - like traverse connecting both cameras in stereo view and the light - sheet optics, guiding the laser beam through the bottom window of the wind tunnel with a traversing system underneath the test section enables moving the stereo PIV measurement volume at the model in x- , y- and z- direction with just one stereo camera calibration needed. In this framework 300 instantaneous 3C-velocity vector fields were measured each in 5 cross flow planes along the flow direction on the suction side of the wing by stereo PIV. The goal of the test program was to track the trajectory of the wake vortex of an optimal strake at several chord positions between the nacelle and the flap of the wing and at 3 different angles of incidence: 7°, 16.5° and 18.5°. In addition the configurations without strake were measured at angles of attack 7° and 16.5° for comparison reasons. A study with four cross-flow planes at the flap position of the model with and without strake at the angle of attack 14° completed this campaign.