CFD-Based Investigation of Rear-End Aerodynamic Devices for Drag Reduction in a Sedan Car

The automobile industry is a vast, continuously changing industry on the cusp of a massive revolution. The developments made by automobile manufacturers have made personal transport as energy efficient as possible. Drag force at highway speeds accounts for over half of the car's resistance. In this study, the focus is on the aerodynamic characteristics of a sedan and the use of CFD to compute the drag force acting on the car, retrofit parts to the rear of the vehicle to reduce the drag force, and consequently improve the aerodynamic performance of the vehicle. This work employed three design interventions in stand-alone and combined modes: a rear spoiler, rear diffuser, and roof side vortex generator. It was found that the maximum drag reduction was 20% for the optimum configuration, reducing fuel consumption by about 10%. It was also found that the average life of the chosen sedan increased by about 35000 km due to the added drag reduction component.