Experimental investigation of aircraft trailing vortices in a catapult facility using PIV

Abstract

The evolution of the trailing vortices behind a free flying aircraft model has been investigated experimentally by means of digital particle image velocimetry (PIV). The measurements took place in the catapult facility of ONERA, Lille, where the near field as well as the very far field of the wake flow can be studied in a ground-based frame of reference. Tracer particles addad to the flow were illuminated by a pulser laser light sheet in a plane crosswise to the flight path of the model. Two CCD cameras recorded neighbouring areas of the flow field simultaneously. Image recording was set off by the launching model crossing a photoelectric barried in order to survey defined planes behind the model. The resulting velocity and vorticity fields give quantitative information on the structure and trajectory of the trailing vortices