Blackwood
Contributor
I didn't want to quote an entire article on golf balls, here on a diving forum... but that effect is evidently not appropriate as a metaphor to what happens with water resistance and a diver.
Maybe, maybe not. It's impossible to make that determination without doing some work.
The dimples reduce the speed needed to cause turbulence. This turbulance, at speed, creates a 'pocket' behind the ball... a 'turbulent flow'.
No, they cause turbulence directly.
What's happening in essence is this: turbulent flow has more energy and a higher velocity gradient (relative to the surface) than an equivalent laminar flow. This increases drag due to skin friction, but it also allows it to make more headway against the adverse pressure gradient.
Turbulent flow (generally speaking) will therefore stay attached longer than will laminar flow (all else being equal).
Separated flow (wake) behind the ball causes form drag. A wake fed by laminar flow is often larger than that fed by turbulent flow since laminar flow detaches sooner.
It's a balancing match between friction and form drag.
I'm not suggesting that a bungeed wing makes more or less drag than a non-bungeed wing of the same geometry. Rather I'm simply poking at the "common sense" notion that bumpy surfaces definitely create more drag than smooth surfaces.