Numerical investigations of curved slanted surface and lower deflector on the Ahmed body

The effects of passive control models on aerodynamic drag and near wake structures of an Ahmed body with a 25° slant angle was numerically studied. 4 different control methods were studied for this purpose. Curvature control method consists of a curved upper edge of the slanted surface. The radius of the curvature was started from 200 mm and ended at 1000 mm radius. Deflector control method consists of a deflector attached on the lower edge of the slanted surface. Length of these deflectors was started from 1% of the body length and ended at 6% of the body length. Later on, based on the best-resulted curvature and deflector control models, a new control model created and called the optimum control method. Lastly, a deflector was relocated on the slanted surface and the deflector end was aligned to the end of the body vertically. Simulations were conducted in Fluent (19.1) software at 60 m/s inlet velocity, which it was equal to Reynolds number = 4.2 x 〖10〗^6. The obtained results and displayed flow structures were compared with the base Ahmed body result. As a result of these simulations, the coefficient of drag was reduced up to 21.16%. Key Words: Drag Coefficient, Lift Coefficient, Ahmed Body, CFD