On Oct 24, 3:28*am, Dancing Fingers wrote:

I thought that was the point of research project? *Why do golf balls
have dimples in the size and geometry that they do and go from there.
Didn't the the old German Stork have a very rough surface in the nose
area? *May thy knew something that we overlook?

Your general thesis that there is some ancient mystery to aerodynamics
that is not well understood by modern aero engineers and not well
modeled by modern CFD software is humorous but not enlightening.
TANSTAAFL and all that.

"Capt. Geoffrey Thorpe" covered it pretty well when he wrote:

The dimples in a golf ball help reduce drag by making
the boundry layer turbulant which helps it flow just a
little further around the back side and reduce the area
behind the ball where the air flow is seperated (compared
to a laminar boundry layer). Also, the dimples work only
across a limited range of Reynolds numbers (less than
3*10^5).

That's pretty much all there is to it. Where you can get laminar flow,
you hang onto it as long as you can because it offers the lowest drag.
Where the laminar flow starts to stagnate and threatens to form a
separation bubble, you trip it over into turbulent with a feature such
as a vortex generator, a turbulator, a dimple, or whatever, because
turbulent flow has less drag than separated flow.

Thanks, Bob K.