The aerodynamic interaction of a rotating wheel and a downforce producing wing in ground effect

The performance and safety of current open wheeler race cars depend heavily on the effectiveness of the aerodynamic package. The front wing and front wheels make a significant contribution and therefore must be well understood. Previous investigations have focused on the aerodynamic characteristics of either an isolated downforce generating wing in ground effect or a rotating wheel in isolation. Investigations that have considering both bodies working in unison conflictingly claim that the addition of a wheel downstream of a wing can aid or hinder the performance of the wing, and the wheel’s aerodynamic performance has not been reported. In order to obtain a more thorough understanding of the interaction of a wing and wheel, experimental results were used to conduct an extensive validation of a computational model, after an equally rigorous verification study had been conducted. A number of investigations were then conducted of a wing and wheel working in unison as well as each in isolation using the computational model. The combined wing and wheel investigation demonstrated that three main interactions can occur, depending on the selection of wing span, angle of attack and height used, while the wheel width and track were found to be less sensitive parameters. The three interacting states differ in the path that the main and secondary wing vortices take around the wheel and the subsequent variation in the combined wake structure. In general, the wing in the presence of the wheel reduced the wing’s ability to generate downforce by up to 45%. This is due to the high pressure regions generated forward of the wheel, which reduce the suction that can be achieved by the bottom surface. This was also found to alleviate the adverse pressure gradients experienced by the wing, and also reduce the drag by up to 70%. For this reason, the downforce loss phenomenon was observed to occur at a height 0.08c to 0.32c lower in comparison to the same wing in isolation, dependant on the wing span. Wheel lift and drag values were also observed to reduce in the presence of a wing by up to 65% and 38% respectively. The upwash and vortices generated by the wing were found to assist in reducing the separation from the contact patch and increasing the separation from the upper wheel tread; a phenomenon also observed during an isolated wheel investigation which was found to reduce the wheel’s lift and drag. As a result, it was shown that the combined wing and wheel downforce and drag optima differed by up to 75% and 25% respectively to those which would be estimated if the two bodies were investigated individually and the results summed. This highlights the importance of investigating these two bodies in unison.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2009

Author dc:creator

• Diasinos, Sammy

• Combined
• Wing
• Wheel
• Aerodynamics

Statement dc:rights

• open access
• CC BY-NC-ND 3.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by-nc-nd/3.0/au/

Language dc:language

EN

Identifier

https://doi.org/10.26190/unsworks/22812

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/44516