Numerical study on aerodynamic drag reduction of passenger cars

Abstract

The scope of this work is to identify potential improvements on Passenger cars Aerodynimcs (Drag reduction and Downforce increase) to help to minimize fuel consumption and hence reduce exhaust emisions. The Ahmed body (Bluff body) is representative of a passenger car under aerodynamical point of view. A lot of studies and literature exists as far as test reports of the Ahmed body on wind tunel tests. This work can be divided onto 2 steps. First step is to perform qualitative numerical simulations of a 3D model of an Ahmed body modified with different aerodynimc improvements such as difuser integration downstream on the underbody of the vehicle (studying different configurations such as diferent lenghts, diferent angles and number an d location of vanes), study of aerodynamic modifications on the rear bumper to improve the weak low pressure region, study of by-pass ducts integration from the front glass to the rear glass, Rear Spoiler integration, vortex generators integration downstream over the roof and a new "double roof" concept. After evaluation of the perormance of such modifications on the Ahmed body, the second step of this work consists to implement a single modification or multiple moidifications on the geometry of a real passenger car and compare (as conclusion of this work) the CFD results of the passenger car quantitative simulations before and after the modifications were implemented.