AERODYNAMIC DESIGN OF A FORMULA SAE RACE CAR

Abstract. The objective of the research in this paper was to maximise the amount of perform-ance enhancing aerodynamic down-force generated by the 2005/2006 University of Auckland Formula SAE race car. This was done through a combination of physical modelling using a rolling road wind tunnel research facility and by using computational fluid dynamics. Computational fluid dynamic analysis was used for the design of the body and under-tray of the vehicle. Optimal design gave a lift coefficient of-0.9 from the under-tray. Simulations showed that when the exhaust was vented into two diffuser tunnels under the car, the down-force was increased by 35%. Half-scale vehicle modelling using the wind tunnel rolling road facility gave a lift coefficient of-2.4. In its optimal configuration, the aerodynamic load on the front and rear wheels respectively was able to be adjusted between 43 % on the front and 57 % on the rear to 33 % on the front and 67 % on the rear by changing the angle of the foils. The drag coefficient varied from 0.9 to 1.1. Full-scale on-track measurements showed that only 6 % less down-force was being gener-ated than was predicted from the wind tunnel test programme, and validated the experimental approach that was taken. Data collected from the car during the endurance event at the 2006 Formula Student Germany competition showed that the aerodynamic package was responsi-ble for a significant increase in the performance of the vehicle under braking and during cor-nering, while the increase in the drag force had only a minimal effect on the top speed which was achieved during the event.