Quote:
Originally Posted by AeroMcAeroFace
So despite following the template, the car still had separation? And it was caused by a very thin light bar. Attachment 29748 So, doesn't that mean that applying a centreline template could be useless unless very small protuberances, such as lights, boot lid gaps or window gaps are taken into account? |
Yes, the drop-off created the sudden alteration in cross-sectional area, and positive adverse pressure spike trigger which Hucho tells us always to avoid in an aft-body, and the elevation of the glass, below the streamlined pathway, precluded any reacceleration of the flow to cross back over the spike threshold. Without a constriction to the flow downstream, there's no opportunity for reattachment.
The flip-up spoiler is introduced to provide the flow constriction.
If the roofline had simply continued on, without deformation, like the Honda, Gen-II Insight, there never would have been any separation.
Protuberances would be okay, as they wouldn't constitute a constriction of the body cross-section.
Gaps are okay, as they're not a 'ventilation', as a reverse-step would constitute.