In recent years, the aerodynamic drag became a major interest of automotive industry as it is one of the main components affecting the fuel consumption. To reduce aerodynamic drag force and improve the energetic efficiency, a complete understanding of the flow around ground vehicles is highly required. This study focused on the accuracy of a three different turbulence models in predicting Ahmed body components drag coefficients. Ahmed Body is a simplified model which mimics the bluff bodies in automotive aerodynamics. This study uses ANSYS Fluent to simulate the flow around Ahmed Body. Three different turbulence models (K-epsilon, K-omega SST and SST) were used in the study. The drag coefficient components for the different sections of the model were validated with the experimental published data. The results have shown that the SST model predicted accurately the total drag coefficient but failed to provide good agreement for the components drag coefficients.

In current study, the aerodynamic drag reduction of a simplified van model was numerically explored by mounting a side flap on the rear end, on the basis of ANSYS-Fluent, an established Computational Fluid Dynamics (CFD) software. A robust Taguchi test design method was leveraged to optimize the independent parameters related to side flap design in order to achieve the best combination for maximum drag reduction with minimum test numbers. The accuracy of the numerical study was validated using the benchmark, Ahmed body model. The current study outcomes established the efficiency of adding a side flap to weaken the longitudinal vortices, at the rear part of the van model, for the purpose of reducing the aerodynamic drag. In this study, the authors achieved a maximum reduction of 11.50% for total drag coefficient and 11.73% for pressure drag coefficient.