17. Ground Based Large Scale Wake Vortex Investigations by Means of Particle Image Velocimetry: A Feasibility Study

The investigation of aircraft wake vortices is a fundamental challenge in aerospace research. The enhanced safety and efficiency given by better prediction and detection of these complex vortex systems is significant. Within AIM several non-intrusive optical methods were considered to visualise and measure the wake vortex of a landing aircraft. The main objective of the herewith presented campaign was the application of the Particle Image Velocimetry (PIV) to the investigation of these vortex flows. This report describes the first steps and approaches for the implementation of a large scale PIV measurement system for the determination of wing wake vortices of a landing aircraft. Many issues have to be addressed before the flyover test could be carried out. During the realisation phase of this experiment several setups were considered and discarded, a prototype of a seeding generator based on helium filled soap bubbles was designed and preliminary studies have been carried out exclusively for the investigation of the laser light sheet behaviour when propagating over large distances. This report presents a summary of all the considerations and pretests for this particular application.