Multi-window PIV for high-lift measurements

Experiments using multi-window, particle image velocimetry (PIV) were performed in the low-speed wind tunnel of Airbus Bremen, Germany, over a two-dimensional, slat/wing/flap model in a high-lift configuration. For this, a system for acquiring PIV data from multiple cameras simultaneously was devised and installed underneath the LSWT. The PIV experiments were performed at the mid-span of the model, for incidences of 12°, 17.5° & 19°. Nearly 5000 PIV images were obtained during the tests, the images capturing the flowfields from the slat wake, slat/wing gap, flow mixing over the main wing, wing/flap-gap and wing wake. The analysis of the results reveals that such a technique is a viable and valuable tool for industrial wind tunnel tests, with high quality data showing the unsteady nature of the slat wake and slat gap flow with distance downstream and unsteady flow separation over the flap.