An Investigation into the Aerodynamic Characteristics of Bluff Bodies in a Vehicle Platoon

This study uses bluff bodies, namely the Windsor model (36% scale), to represent mid-sized passenger vehicles, contributing a new data set on two-vehicle platoons at spacings of 0.5*vehicle length. Vehicle geometry was systematically modified to assess its effects on the whole platoon, as well as the two vehicles individually. The data was gathered by CFD and validated using experimental data from the Coventry University wind tunnel. Studies on CFD methods for platoons are presented, concluding that small-scale simulations with a fine mesh are better solved with a low wall y+ approach to wall treatment, and multi-phase mesh independence studies provide optimised cell counts and processing times. The results from all 16 platoon simulations showed an overall reduction in drag for the platoon, regardless of vehicle geometry, although some configurations benefited more than others. The front end of the trailing model was found to be the critical area of geometry in terms of drag reduction, with the square fronted “H1” models benefitting platoons the most. Finally, the data were used to suggest potential negative effects of platooning on the stability and cooling of trailing vehicles.