Aerodynamic design optimization of an automobile car using computational fluid dynamics approach

Aerodynamic drag is the force acting on the surface of the automotive car which opposes its motion. To overcome this force, excess fuel has to be burnt in the engine which leads to an increase in the specific fuel consumption and lowers the efficiency of the car. The drag force can be reduced by reshaping the rear end, covering the underside of vehicles and reducing the number of protrusions on the surface of the car. The main cause for drag is a low-pressure (wake) region created at the back portion of the car. This can be reduced by cutting an underneath slot from the front to the rear end. Because of this, air gets flown inside the duct and leaves via rear end to decrease the wake region formed. Therefore, drag can be reduced significantly which leads to fuel efficiency improvement. The flow regions are identified where the large pressure drag is produced and design parameters are identified and suitable geometric modifications are implemented in the car design. A comprehensive flow analysis is carried out by using ANSYS Fluent and results are interpreted.