turbulation from dimples

[Airhog]

i noticed that the surface of golf balls is not smooth but dimpled. I recall pictures from my fluid mechanics book demonstrating the effects of a rough vs smooth surface on an air stream. The rough surface creates a turbulent boundry layer resulting in later separation and lowering the drag. We have used turbulator spars to do this on wings but has anyone tried using a rough surface on or near the leading edge? Would it make enough improvement to be worth trying?

[Sparky Paul]

NASA found the anti-dimple worked better...

[Ollie]

Some low camber airfoils that are quite thin (< 5 or 6 % thick) do not benefit from turbulation even at very low reynolds numbers. Other airfoils may benefit to varying degrees depending on reynolds number.

The S7075, for example, was designed specifically to benefit from turbulation in a particular way. See Summary of Low Speed Airfoil Data, Vol. 3 by Selig etal. pages 28 and 29.