Aerodynamic Drag Reduction on Vehicle with and Without Spoiler

Present days the demand for high speed passenger vehicles is increasing but doing so involves dealing with vehicle stability concerns. Forces like Drag, Lift and weight acting over a vehicle when moving on road have significant impact over the fuel consumption. So it is important to optimize these parameters to obtain greater efficiency. Spoiler is such a device which is used to increase fuel efficiency by reducing drag and also improving the down force. Adding a spoiler at the very rear of the vehicle makes the air slice longer, gentler slope from the roof to the spoiler, which helps to delay and reduce the flow separation. Reducing flow separation decreases drag, which increases fuel economy and less pollution as well; Also a spoiler is in a shape of inverted airfoil produces negative lift (down force) which helps to keep the vehicle attached to the ground at high speeds and corners. This thesis will present a simulation of flow around Passenger vehicle with spoiler positioned at the rear end using commercial fluid dynamic software. The thesis will focus on CFD-based lift and drag prediction of a passenger vehicle with and without spoiler, where the spoiler is mounted at the rear edge of the vehicle. A 3D computer model of 4-door passenger vehicle (which is designed with commercial CAD software Catia®) will be used as the base model. Different spoilers will be positioned at the rear end of vehicle to reduce the overall drag produced and the simulation will be performed using CFD code CFX to determine the aerodynamic effects of spoiler.