[aerohead]

Originally Posted by tomi_k

The Cd 0.158 shape start to look more or less like Onorato's shape on page #4 on below publication....

https://repository.lboro.ac.uk/artic...rag/13516313/1

I revisited the publication. It turns out that what Onorato presented is a von Mises profile, invented by Richard Von Mises, in 1915.
It's a 'fast' aft-section contour which could experience burble-point, then stall, compared to, say, a Clark-Y profile at the same angle of attack.
The 'reflex-camber' at the rear literally acts as a 'spoiler', re-accelerating the flow to mitigate the adverse pressure gradient of the higher than allowed pressure rise which threatens separation and stall.
GM used it with their 1993 Impact-EV1 LSR to reduce lift and drag.