A Relationship between Lift and Lateral Aerodynamic Characteristics for Passenger Cars

2010-01-1025

04/12/2010

Event
SAE 2010 World Congress & Exhibition
Authors Abstract
Content
Aerodynamic aids, such as spoilers, applied to the rear of cars can provide drag reduction to improve performance, or can enhance high speed stability by reducing lift at the rear axle. In some cases these can be conflicting demands. It has been noted, however, that when rear axle lift is reduced there is often a reduction in yawing moment which has a beneficial effect on crosswind sensitivity. Wind tunnel results from real road vehicles are presented to illustrate this effect. This beneficial relationship is further explored in a wind tunnel experiment using simple models to represent road vehicles. Force and moment coefficients as a function of yaw angle are measured for a range of vehicle geometries which generate a substantial variation in lift. It is shown that as lift is reduced, yawing moment is also reduced, while side force and rolling moment are increased. It is demonstrated that the changes to yawing moment and side force result from the pressure distribution on the rear pillars. Exceptions to this simple relationship between lift and yawing moment are briefly discussed.
Meta TagsDetails
DOI
https://doi.org/10.4271/2010-01-1025
Pages
11
Citation
Howell, J., and Baden Fuller, J., "A Relationship between Lift and Lateral Aerodynamic Characteristics for Passenger Cars," SAE Technical Paper 2010-01-1025, 2010, https://doi.org/10.4271/2010-01-1025.
Additional Details
Publisher
Published
Apr 12, 2010
Product Code
2010-01-1025
Content Type
Technical Paper
Language
English