This document contains the analysis and optimization at aerodynamic level of the exterior geometry of the prototype car model Arcfox 7 of the Chinese brand BAIC, fully developed by the automotive engineering company QEV Technologies, using the Computational Fluid Dynamics (CFD) method and according to the client¿s objectives. For this purpose, a 3D wind tunnel scenario with the appropriate physical conditions is modelled using StarCCm+ software. The customer demands a Cd of less than 0,35, an axle load distribution of 40:60 approximately, maximization of aerodynamic efficiency and all this without excessively modifying the visible bodywork geometry. In the first instance, two versions of the model have been analysed, one with a tunnel bottom configuration and the other with a flat floor, to choose the best option. Even so, even before the CFD analysis, the implementation of the flat floor was already clear, given the company¿s experience with this type of bottom and the packaging of the components in the interior volumes. At this point, the model offers starting results, far from meeting the objectives, of Cd = 0,36, Cl/Cd = 0,36 (lift) and a 12:88 load distribution. The first optimization guidelines are given according the de analysis of the data obtained by CFD simulation and the optimization in 2D environment of the diffuser is performed. Once the changes to the geometry are applied, very good results of Cd = 0,35, Cl/Cd = -1,22 (downforce) and a load distribution 35:65 are obtained. The porous media of the radiators are implemented in the analysis. A second optimization of the model is performed and new guidelines are offered again from the previous version, this time without rear wing, at the client¿s request. Before a new direction is taken on the rear wing geometry, a Cd =0,31, Cl/Cd = -1.93 and a 59:41 load distribution are obtained. Lastly, the customer opts for an active wing and a new airfoil is generated and an optimized position, again by 2D analysis. With a retracted wing configuration, a Cd = 0,31, Cl/Cd = -0,58 and a load distribution of 87:13 are recorded. Finally, with extended wing configuration all objectives are achieved and the development process is finish for the moment. Cd = 0,34, Cl/Cd = -1,24 and a load distribution of 42:58.
