Aerodynamic optimisation of Formula student vehicle using computational fluid dynamics

Abstract

This work aims to improve the external aerodynamic characteristics of the 2017 University of Huddersfield Formula SAE vehicle. To improve dynamic performance in the SAE events, a multiple-element rear wing was developed, which incorporated adjustable elements to constitute a drag reduction system (DRS). A numerical modelling approach was adopted to produce a suitable design. A simplified model of the vehicle was created to obtain baseline coefficients of lift (CL) and drag (CD). The rear wing was optimised to find the peak configuration generating maximum downforce. The results show that the incorporated rear wing improved the vehicle’s CL from 0.21 acting in the positive Y axis (lift) to 1.15 acting in the negative Y axis (downforce), whereas the CD increased from 0.71 to 1.21. However, the DRS configuration reduced the CD to 0.79. Using the obtained lift and drag coefficients, vehicle performance was estimated, such as maximum cornering speed, straight-line top speed and straight-line acceleration capabilities. The rear wing improved the theoretical maximum cornering speed by 3.1% for a corner radius of 13 m. The DRS increased the theoretical top speed by 18.2% compared to a fixed wing configuration. Acceleration potential increased by 15.7% at 25 m/s with the DRS open. The final section of the study used an online simulator (FSAESim) to make predictions of the acceleration event time, which were compared to the track results from the 2017 Hungary SAE event. The results showed a 97% similarity.