Flow Mechanisms and Aerodynamic Optimization of Dual-Element Rear Wings via Orthogonal Design of Experiments, Computational Fluid Dynamics, and Wind Tunnel Testing

Rear wings play a critical role in Formula 1 race cars by generating a large proportion of the total aerodynamic downforce, and this study examines the aerodynamics of a dual-element rear wing within a Formula 1 framework using a combined methodology that includes theoretical analysis, computational fluid dynamics (CFD), design of experiments (DoE), and wind-tunnel testing. A two-stage Taguchi approach is employed to efficiently identify and optimize key geometric parameters with the aim of improving the lift-to-drag ratio while maintaining sufficient downforce. The theoretical analysis provides a physical basis for interpreting the behavior of multi-element wing systems, while CFD results show that the optimized configuration achieves improved aerodynamic efficiency through balanced pressure recovery, controlled boundary-layer development, and reduced vortex-induced losses. Wind-tunnel experiments are used to validate the numerical predictions, and a close agreement in lift-to-drag ratio is observed despite differences in Reynolds number. Overall, the results indicate that the flap element angle of attack is the dominant factor affecting aerodynamic efficiency, whereas camber distribution mainly controls the trade-off between downforce and drag, with a moderate camber of approximately 4% offering the most favorable compromise. Flow-field analyses link superior performance to favorable pressure recovery, reduced viscous dissipation, and controlled vortex dynamics, while experiments highlight the sensitivity of dual-element wings to off-design angles of attack. In the end, through numerous optimization steps, this study produced a package of four rear wing profiles, all with a downforce-to-drag ratio above 10, with the best case having a ratio of 11.88. On top of the high efficiency, these rear wing profiles alone produced at least 564.68 Newtons and up to 816.91 Newtons of downforce at a Reynolds number of around1.2×106. The success in optimizing aerodynamic efficiency while generating substantial downforce verifies the viability and efficacy of the methods presented in this study. Future work should explore other potential factors impacting dual-element rear wing performance, including different camber and thickness parameters, concavity control, and gurneys, to develop a more comprehensive aerodynamic performance map.