On the Development of a Fully Automated Numerical Methodology to Improve Vehicle’s Aerodynamics Optimizing its External Shape

Car manufacturers have a growing interest in developing more efficient vehicles. New technologies have emerged in different areas one of them is vehicle aerodynamics. The aerodynamic resistance, i.e., the forces generated by the air in a vehicle, has considerable influence on fuel consumption.

In this paper it´s presented a computational methodology using CFD (Computational Fluid Dynamics) and optimization tool to evaluate production vehicle and indicate possible ways to reduce its drag coefficient. Efforts are concentrated on modifying the geometry of the external design, a procedure whereby vehicle´s regions of interest are chosen to be valued on a pre-set geometric range parameters, arranging a DOE (Design of Experiments) that are evaluated virtually. In a fully automated procedure, changes are made to these parameters using morphing tools and then CFD calculations are performed. Software ANSA and Star-CCM + are respectively used. Results are then evaluated according to the statistical approach of DOE indicating which regions have higher sensitivities on the drag coefficient. Full automation of the process makes it cheaper and faster. Its results become a very important information for developing a more aerodynamic vehicle and so, improving fuel economy.