CFD Analysis of slipstreaming in NASCAR

• Main Author: Edwin Gan Chern Junn
• Published: 2023
• Subjects: Computational fluid dynamics; Race car aerodynamics; Race strategy; Motorsport; Automotive

NASCAR has given enormous concentration and importance on aerodynamics in racing with drivers relying solely on aerodynamic techniques in pursuit of a first-place finish. The implementation of tapered spacers to reduce the output power of NASCAR race cars for track safety has caused drivers to resort to aerodynamic techniques especially since aerodynamic drag accounts for roughly 90% total resistance at top speed. However, little-to-no analysis has been performed on aerodynamic techniques such as slipstreaming and side drafting employed specifically in NASCAR racing. In pursuit of addressing this gap, a verification study was first conducted to evaluate the accuracy of the car model employed in CFD analysis. Also, a mesh independence test and a comparison between half and full model simulation were conducted in the selection of optimum settings for the studies that follow. A comprehensive investigation of the effects of slipstreaming was conducted by varying the vehicle spacing between platoon members as well as the platoon population. An auxiliary study of the effects of side drafting was later performed by varying the longitudinal position of the trailing car relative to the leading car and the lateral separation between both cars. Conclusive findings on the best strategies in NASCAR racing based on car placements in slipstreaming and side drafting configurations were obtained using CFD.