LES of the flow around several cuboids in a row

• LES was used to study the flow around a four-vehicle platoon.
• One of the platoon members was oscillating along the longitudinal axis.
• Results of LES simulations were used to analyze the flow.
• Oscillation effects were highlighted.
• The oscillation of a platoon member can have dramatic effect on the drag force.

This paper presents Large Eddy Simulations (LES) of flow around a four-vehicle platoon when one of the platoon members was forced to undergo in-line oscillations. The LES were made at the Reynolds number of 105 based on the height of the vehicles. Combinations of two different frequencies corresponding to non-dimensional frequencies at the Strouhal numbers St1 = 0.025 and St2 = 0.013 and two oscillation amplitudes were used in this study. The methodology was validated by comparisons with data from previous experimental investigations. In order to highlight the dynamic effects, comparisons were made with steady results on a single vehicle and on a four-vehicle platoon. Large differences were found in the flow structures between quasi-steady and dynamic results. Furthermore, the behavior of the drag coefficient of the upstream neighbor of the oscillating model was investigated.