Shape modification of Ahmed body to reduce drag coefficient and determination of turbulence model

In this study, the aerodynamic analysis of Ahmed body which is generic automobile model performed to determine convenient turbulence and reduce drag coefficient by modifying shape model. For purpose, Computational Fluid Dynamics (CFD) carried out using different models that are Spalart-Allmaras, (Shear Stress Transport) SST k-ω, Standard k-ε, Realizable (Re-Normalisation Group) RNG k-ε models. The results compared with experimental data available in literature. show gives superior performance when other order coefficient, upper region sides rounded applying fixed blend radius 25 mm. smooth surface can provide high point aerodynamics. CFD solution then repeated for modified result value reduces about 6%. addition, second modification both rear underside chamfer 50 mm also applied body. However, reduction level approximately same first pressure contours velocity streamlines presented baseline bodies.