Drag Reduction on a Three Dimensional Teardrop-Shaped Body Car with Different Stagnation Points

The long-term goal in the automotive industry is to reduce fuel consumption and environmental pollution without compromising the aerodynamic performance of the car. Herein, the aerodynamic performance of an in-house designed Shell Eco-Marathon prototype car is analyzed using Computational Fluid Dynamics simulations. Shape optimization of the Shell car is executed to reduce drag by modifying the rear underbody profile and stagnation point position. The effect of one modification to another is studied to determine the changes to overall flow around the car and, more importantly, the lift and drag coefficients. It has been found that the stagnation point height has a higher influence on the aerodynamic performance of the car compared to variations of the rear underbody, with optimum drag reductions of 17% and 10%, respectively. Moreover, combining the two best configurations to the car reduces CD by 25%, and this marks the highest drag reduction achieved in this study.