The effect of aspect ratio on the wake of the Ahmed body

This paper seeks to further elucidate the wake of the Ahmed body by investigating how the time-averaged flow structures vary with frontal aspect ratio. High-resolution particle image velocimetry results are provided for eight different width Ahmed geometries at $$\text {Re}_{\sqrt{FA}}=3\times 10^4$$ Re F A = 3 × 10 4 .

It is shown that the narrower the body, the greater the downwash over the back slant, meaning the flow remains more attached. At a critical aspect ratio ( $$=1.9$$ = 1.9 ), the flow downstream changes.

The separation over the back slant is shown to be affected by the , and this in turn has a significant effect on the circulation in the c-pillar vortices.