Qualitative and Quantitative Correlation Study for Exterior Aerodynamics for Automotive Vehicle

The objective of the exterior aerodynamic performance assessment of automotive vehicles is to reduce the aerodynamic drag pressure and rear side wake zone, which improves overall energy consumption of the vehicle. Almost 30 to 40% of the energy is required to overcome the drag force and wake zone pressure offered by the air on the automotive vehicle. With the increase in high performance computing power (HPC) and its affordability, computational fluid dynamics (CFD) has become a popular and more effective tool for aerodynamic design and analysis in the automobile industry. In the real-world scenario, automotive vehicle is subjected to varying wind and operating conditions which affect its aerodynamic characteristics, and therefore it is difficult to reproduce such physical phenomenon in a conventional wind tunnel. Hence, the entire aerodynamic assessment was done in wind tunnel which is equipped with advanced aerodynamic assessment techniques like wheel rotations, boundary layer suction, moving ground etc. The current work mainly focuses on measurement of pressure coefficients through pressure tapings provided on the vehicle rear side to capture rear wake structure using tomography method. Computational fluid dynamics has the immense potential of becoming a cost-effective way to achieve such real-world scenario in a virtual environment. Finally, paper summarizes CFD simulation correlation studies with wind tunnel test of the automotive vehicle for drag forces, pressure coefficients across the various locations and wake structures at vehicle rear side.