Aerodynamic Optimization of a Formula SAE Body

In an effort to increase cornering speeds, and cooling system reliability on MSU-Mankato’s Formula SAE car, the sidepod, which houses the vehicles radiator, and an undertray, which mounts to the vehicles underbody, was optimized using computational fluid dynamics. An undertray featuring diffusers was utilized to increase downforce, in-turn increasing cornering speed. The diffusers inlet area, ramp angle, and length play an important role in force generation, all of which were altered and tested. Alternative sidepod designs were also created, focusing mainly on the effects of inlet size, length and shrouding. Each design was simulated in a 3- dimensional fluid domain using Star +CCM, a computational fluid dynamics software program. Once each design was simulated, the tests showed the optimum design to be one with a large enough inlet area to ensure maximum airflow, but shaped to allow superior air quality. The undertray geometry was altered with the maximum downforce evident when the diffuser angle is large enough to prevent flow separation, and while the diffusers throat was positioned at the vehicle center of gravity. Once the body was constructed, the simulations values were validated with full-scale flow rate, and instantaneous velocity measurement. An 1/8th scale model was created using fused deposition modeling, and was wind tunnel tested to validate the lift and drag forces calculated in the simulations