RT Journal Article T1 On the ground effect in passive control using deflectors at the rear part of an Ahmed body A1 Solis, P. A1 Duran, E. A1 Gutiérrez-Castillo, Paloma A1 Del-Pino-Peñas, Carlos Manuel K1 Aerodinámica PB Elsevier YR 2026 FD 2026-02 LK https://hdl.handle.net/10630/46095 UL https://hdl.handle.net/10630/46095 LA eng NO P. Solis, E. Duran, P. Gutierrez-Castillo, C. del Pino, On the ground effect in passive control using deflectors at the rear part of an Ahmed body, European Journal of Mechanics - B/Fluids, Volume 119, 2026, 204495, ISSN 0997-7546, https://doi.org/10.1016/j.euromechflu.2026.204495. (https://www.sciencedirect.com/science/article/pii/S0997754626000427) Abstract: Drag measurements were performed over an Ahmed body with a 25-degree slant angle modified with rigid deflectors at the top rear edge. Experiments were conducted on both a wind tunnel and a towing water tank in the range of Reynolds numbers based on the height ReH=30×103−170×103. In the wind tunnel experiments, drag measurements were acquired at two ground clearances: a nominal height, and a larger distance 14 times the nominal one to minimize the ground effect. The inclusion of a deflector with an inclination in the range of α=[−8°,−4°] decreases the drag coefficient by up to 27% over the base case without deflector. Furthermore, an analytical correlation was developed to predict the drag coefficient as a function of Reynolds and deflector angle for each ground clearance. Additional 2D-PIV measurements obtained in the towing tank confirmed that the circulation of the C-vortex is significantly reduced compared to the base case. These results demonstrate that the observed drag reduction is primarily associated with a weakening of the induced wake structures. Keywords: Ahmed body; Passive control; Bluff body flow; Automotive aerodynamics NO Funding for open access charge: Universidad de Málaga / CBUA DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 21 mar 2026