Effects of approach flow conditions on the unsteady three-dimensional wake structure of a square-back Ahmed body

We investigate the effects of approach flow conditions (uniform flow (UF): Case A and thick turbulent boundary layer (TBL): Case B) on the unsteady three-dimensional wake characteristics and bimodality of a square back Ahmed body. Using improved delayed detached eddy simulations we show that TBL induces a much higher ground clearance momentum deficit than UF, which significantly alters wake asymmetry orientation in the wall-normal plane and completely suppresses bimodal wake behavior in the spanwise plane. Both time-averaged and time-resolved turbulence statistics are used to explore the differences between the wake structure of the Ahmed body subject to the two approach flow conditions.