Unsteady-Wake Analysis of the Aerodynamic Drag of a Notchback Model with Critical Afterbody Geometry

The flow around high speed trains

“…It is clear from the literature that the precise nature of the wake varies from vehicle to vehicle, but there seem to be a relatively small number of flow mechanisms that can exist in some combination or other-shear layer separations, longitudinal helical flows, vortex streets and a separation cavity (Vino et al, 2005;Sims-Williams et al, 2001;Nouzawa et al, 1992). All of these phenomena are subject to instabilities with Strouhal numbers (based on vehicle velocity and some representative frontal dimension) between 0.05 and 0.4.…”

Flow structures in the near-wake of the Ahmed model

“…corresponds to the separation of a secondary vortex generated between the main trailing vortex and the c-pillar, while A 0 C represents the attachment of the main vortex. Nouzawa et al (1992) extended an earlier investigation with an unsteady analysis of a notchback model shape. They observed that an arch vortex (initially found on the rear window and deck-lid of an earlier study) exhibited significant unsteady characteristics.…”

Structures of Flow Separation on a Passenger Car

“…In vehicle aerodynamics this method was used to characterize occurring flow structures and to derive the flow development [8,9,10,11]. Also the influence of the backlight angle, deck lid length or C Pillar length and radius onto the flow pattern was shown by many researchers, for instance [12,13,14,15,16]. But how these patterns are formed and under which conditions they occur is still an insufficiently answered question.…”