Materials for Dimple Surfaces (reduced separation)

[aerohead]

It would be nice if Peugeot discusses the technology.
As I understand it,on a shark,it's skin sequesters pockets of dead water between all the dendrites,and water flowing over the skin flows over as much 'water' as skin,reducing surface friction drag.Penguin feathers trap air bubbles.
On a car,the entire surface is already coated with dead air,and airflow never actually touches the cars surface.
The turbulent boundary layer would be quite mature by the time it reached the shark skin.
I'd suspect that if the shark skin lowers drag,then it's doing it as micro-VGs,amplifying the kinetic energy mixed in to thwart separation.

[cowmeat]

So did the dimple thing pan out or not?

I tried to read through it all, but a lot of the posts were more than a paragraph so I skipped all those. I may have only gotten half the story!

I've wondered about the dimples myself, and I'm surprised that on a site full of people sporting wheel skirts, Kammbacks, boat tails and vortex generators that somebody hasn't already taken the round end of a ball peen hammer to their hooptie and tried this!

[freebeard]

As templating as that sounds, you'd need a female die backing each hammer-blow to form an effective dimple, otherwise you'd get a low spot with a ding at the bottom.

As a first approximation, assume the dimple on a car should be the same size as one on a golfball. The scale isn't that far off. Then assume a different way to interact with the air may operate on a different [smaller] scale. Then consider the Lotus flower that is hydrophobic and therefore self-cleaning.

A small-scaled widespread aero-phobic pattern that could break the grip of the wake on the afterbody would be awesome, even if it only come in red.

[ChazInMT]

Oooooooo...Shark Skin!! I love the look of it!! Here is an Eye of Science pic that is amazing......These look like the shapes of craft from an alien invasion force! It is dumbfounding to me how this shape evolved.