Optimization of SAE Formula Rear Wing

Abstract

This work deals with taking advantage of the available numerical methods when trying to excel in automotive competition. First, the optimization problem is outlined, to be followed by the proposed numerical solution, as well as the practical consequences of this solution, not as a proof of validity of the numerical approach, but rather as a description of a modern design flow.Formula SAE is an international competition having the common goal of designing and manufacturing of a racing car. While efforts have been made to keep the average velocity as low as possible, for safety reasons (around 50 km/h), by designing an especially tortuous track, there is fierce competition among competitors. This, rather low, velocity presents an additional challenge before the designerincreasing downforce results in higher corner speeds, and this, in turn, leads to better final times during the competition. The design criterion was, therefore, to construct, and manufacture a vehicle which exerted as much downforce as possible.The body of work related to the rear wings has been performed at Monash University see Wordley and Saunders [1]. However, their work covered 2D computational fluid dynamics (CFD) analysis citing availability of a full-scale wind tunnel. This approach, while completely understandable, is not suitable for those without access to such expensive facilities. We believe and have proven in this work, that similar results can be achieved using full-scale 3D CFD modeling. In addition, we believed that modeling rotating wheels and a moving road were absolutely necessary in order to achieve meaningful results. Also, Wordley and Saunders [1] were not concerned with optimization of height but were rather changing the angle of attack, such approach being understandable for wind tunnel tests. Doddegowda et al. [2] have also shown generally agreeable computational results without focusing on particular parts of the car. On the contrary, De Silva et al.[3] used CFD for fine-tuning of side panels in order to maximize the use of cooling air. They used moving ground however, not spinning wheels, which, in our opinion, is absolutely necessary to capture the vortex formation around the side walls of the car. The importance of a rotating wheel was, albeit from a different perspective, confirmed by Huminic and Chiru [4].The surprising scientific result shown herein is that the effect of the slat was more pronounced than the effect of the second flap, for the maximum angle of attack, at the upmost main rear wing position, and this is documented herein. Unfortunately, the final design could not incorporate this result as this would • Several different layouts were analyzed. Optimization of SAE Formula Rear Wing• The addition of a slat at the expense of a second flap results in significant increase of downforce (about 6 %).• Boundary layer separation causes a significant decrease in lift, and occurs for higher angles of attack in the case of using a slat as opposed to the case without a slat and with the second flap.

Vehicle Aerodynamic Stability Analysis under High Crosswinds

“…Experiments are costly and the required special equipment is not widely available, which poses a serious problem for wind tunnel experiments. Recent and similar works [1] and [18] to [20] (Table 4) crosswind situation. In this study, we use the stability criteria relationship derived in [2] to analyze three crosswind accident types: rollover, side-slip or lateralslip, and rotation.…”

CFD Analysis of the Location of a Rear Wing on an Aston Martin DB7 in Order to Optimize Aerodynamics for Motorsports

“…Unfortunately, these resources are only available to race car manufacturers and professional race teams, leaving the amateur "club" racer to rely on off-the-shelf parts from specialty suppliers often without being able to verify performance gains except by testing on the racetrack, which is time-consuming and expensive if many variables are to be investigated. Exceptions have been the extensive CFD work carried out by many University groups on Formula SAE cars [4][5][6][7], as well as detailed studies using the RANS model to determine the effect of devices such as the Gurney flap for car racing applications [8,9]. The goal of the present study is to determine if modest cost (time) calculations are suitable for determining the initial location parameters of aerodynamic devices to minimize trial-and-error approaches for club motorsports.…”

Integrative CAE-Driven Design Process in the Embodiment Design Phase of L7e Vehicle Structures

“…But the reduction in vehicle energy consumption can be realized mostly through mass reduction. Additionally, the shapes of the new vehicle body-in-white parts such as swooping rooflines, wheel covers and housings, extra front and rear spoilers, and rear wings, have a significant impact on the aerodynamic drag, which plays a crucial role in the development of energy-efficient commuter and premium luxury vehicles as well as track-oriented sports cars [14]. The lightweight body-in-white constructions frequently utilize a mix of various material types, which results in advanced joining technology such as adhesive bonding, rivets and blind-rivet joints, yet the fatigue life estimation is complicated for these types of connections [15].…”