Aerodynamic Design for SR11 (Formula SAE Racing Car) 2013-32-9100
Nowadays, cornering performance of FSAE (Formula SAE) cars are dramatically improved due to less mass, kinematic developments and tires. In such circumstance, under high speed conditions, aerodynamical devices work better. It had been decided to attach aerodynamical devices that consist of front wing, rear wing, diffuser (floor) and deflector for SR11 (Fig. 1, Table 1), a FSAE car developed by Sophia Racing (Japan).
Table 1Vehicle configuration of SR11
To start with developing aerodynamical devices, it had been assumed that how they work. Lap time simulation had been done with VI-car-realtime, which shows the laptime could be shorten by 2 seconds of 60 seconds for a usual FSAE endurance course with 60kgf at 60km/h downforce. Dragforce had been assumed to work well while once, it had been supposed to have a bad influence for laptime. The reason why it works well is at high speed, it works as extra braking force even without tires doesn't contact with ground or unfavorable load distribution. Then, 60kgf downforce was a target, while no target with dragforce. To maximize downforce, optimization for wing shapes with adjoint solver had been done.
With these developments, 55kgf at 60km/h has been measured with load gauges, around 10% G for each lateral and longitudinal has been measured with G sensors.