posted on 2010-10-13, 08:46authored byJeff Howell, Chris Sherwin, Martin Passmore, G.M. Le Good
Growing concerns about the environmental impact of road vehicles will lead to a reduction in the aerodynamic drag for all passenger cars. This includes Sport Utility
Vehicles (SUVs) and light trucks which have relatively high drag coefficients and large frontal area. The wind tunnel remains the tool of choice for the vehicle aerodynamicist, but it is important that the benefits obtained in the wind tunnel reflect improvements to the vehicle on the road. Coastdown measurements obtained using a Land Rover Freelander, in various configurations, have been made to determine aerodynamic drag and these have been compared with wind tunnel data for the same vehicle. Repeatability of the coastdown data, the effects of drag variation near to zero yaw and asymmetry in the drag-yaw data on the
results from coastdown testing are assessed. Alternative blockage corrections for the wind tunnel measurements are examined. A reasonable correlation between wind tunnel and on-road aerodynamic drag data is established for the configurations tested.
History
School
Aeronautical, Automotive, Chemical and Materials Engineering
Department
Aeronautical and Automotive Engineering
Citation
HOWELL, J. ... et al., 2002. The aerodynamic drag of a compact SUV as measured on-road and in the wind tunnel. SAE Transactions. Journal of Passenger Cars - Mechanical Systems, SAE Paper No. 2002-01-0529, 2002, pp. 583-590.