Authors: Tracie Barber
Addresses: School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW 2052, Australia
Abstract: When a lifting body produces wingtip vortices near a surface, the lateral movement of these vortices as they travel downstream can differ from that seen in free flight. This variation may also result in a change in aerodynamic forces. A Gottingen 723 wing section was mounted at a constant angle of attack of five degrees and at various clearances above a stationary ground plane in a wind tunnel. The wing was studied in both lifting and down-force configurations and the Reynolds number of the flow was 20,000. The wingtip vortices were investigated using laser sheet smoke visualisation (LSV) in order to visualise the flow and to gain a quantitative estimate of the downstream progress. Significant lateral movement of the wingtip vortices near the ground was seen (up to 40% span movement at ten chord lengths downstream) for both lifting and down-force; lifting wing vortices moved outboard and down-force wing vortices moved inboard.
Keywords: wingtip vortices; ground effect aerodynamics; laser sheet flow visualisation; aerodynamic forces; constant angle of attack; stationary ground planes.
International Journal of Aerodynamics, 2010 Vol.1 No.1, pp.18 - 27
Available online: 21 Feb 2010 *Full-text access for editors Access for subscribers Purchase this article Comment on this article