An Investigation of Changes in APillar Vortex Dynamics with Windshield Inclination

Abstract:

The influence of windshield inclination on the dynamics evolution of the Apillar vortex produced by Dihedron models is investigated both experimentally and numerically. The timeaveraged aerodynamic drag and surface static pressure are captured by wind tunnel experiment, and detachededdy simulation (DES) is employed to characterize the details of the topology of Apillar vortex. The DES results are validated by experimental results both herein and from the reference paper. The breakdown phenomenon of Apillar vortex is described by the DES results. The Apillar vortex demonstrates different flow patterns with windshield inclination variation, which is dominated by the vorticity balance theory in the primary vortex. Both experimental and numerical results show that the aerodynamic drag of Dihedron models increases when enlarging the windshield slant angle. The breakdown trend of longitudinal vortexes is discussed and a potential drag reduction scheme is visualized. Finally, wall dynamics of Dihedron models and its influence on the incabin noise are emphasized.

Key words:Apillar vortex; automotive windshield inclination; vortex breakdown; vorticity balance; Dihedron model; detachededdy simulation