Investigation of the Effects of using Rear Wings in the Diffuser Region on the Aerodynamic Performance of the Ahmed Body

In the current research, different configurations of wing-equipped diffusers at the rear of the standard Ahmed body were investigated to identify the optimal model for drag reduction and downforce enhancement. The investigations were conducted at Reynolds numbers ranging from 0.33×106 to 2.01×106. Initially, the optimal diffuser is found to be 10°, achieving significant reductions in drag and increases in downforce. Thereafter, a rectangular wing with a high-cambered airfoil was integrated into the diffuser region in eight different configurations, varying in angle of attack and horizontal and vertical positioning. The configuration with the wing at 10° angle of attack and positioned vertically at 1/4 of the underbody height and horizontally at the beginning of the diffuser demonstrated the most desirable aerodynamic performance regarding drag reduction. The second case, with the wing at 10° angle of attack and positioned vertically at 1/2 of the underbody height and horizontally at the end of the diffuser, achieved the most desirable aerodynamic performance regarding downforce enhancement.