Simulations of bluff body wakes and vehicle aerodynamics

The paper discusses how flow-resolving LES simulations are used to predictand explain flows around vehicle-like bluff bodies. Several different applications of the LESare presented including bodies in unsteady winds, flow control and asymmetry phenomenaof the wake behind notchback geometries. The focus of the paper is in explaining theflows around vehicle-like bluff bodies using numerical simulations. Differences betweenresults of dynamic and quasi-steady tests are studied and the flow mechanisms responsiblefor phenomena such as hysteresis, phase shift and overshoots of forces and moments areexplained. Several different applications of flow control are explored and it has been shownthat LES is useful as a tool for designing the means of flow control for drag reductionpurposes. The last example of simulation of notchback geometry demonstrates the usageof LES to explain the phenomena of wake asymmetry in a symmetric geometric set-up. Although, the observation of such asymmetry is documented in the literature, theunderplaying flow phenomena is unknown and the present LES gives first indications forthe explanation of the undelaying flow mechanism