Topology and dynamics of the A-pillar vortex

Benjamin Levy (1, 2) , Pierre Brancher (1)

1 IMFT - Institut de mécanique des fluides de Toulouse
2 Shanghai Jiao Tong University [Shanghai]

The topology and dynamics of the flow bypassing an automobile A-pillar modeled by a 30° dihedron are investigated experimentally. The various components of the A-pillar flow are identified by means of low and high frequency particle image velocimetry. For each component, the time evolution of the position, displacement, vorticity magnitude, circulation, and fluctuating kinetic energy are analyzed along the A-pillar. More precisely, the flow by passing the A-pillar is composed of two vortex structures with different behaviors. The major structure grows in size, circulation magnitude, and total amount of fluctuating kinetic energy along the A-pillar, whereas the minor structure does not vary significantly. Finally, the displacement of the major structure is identified as a movement of precession and the influence of the A-pillar geometry is emphasized.

Mots clés: Vortex dynamics; A-pillar vortex; PIV; POD

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Benjamin Levy, Pierre Brancher. Topology and dynamics of the A-pillar vortex. Physics of Fluids, 2013, vol. 25, pp. 1-15. ⟨10.1063/1.4792710⟩. ⟨hal-00874271⟩