>Golf balls are dimpled so they go farther. Apparently, air passing
>over a smooth golf ball creates a lot more friction than air passing
>over a dimpled one. This logic would seem to be the opposite of making
>stuff smooth to increase airflow. If the friction goes up, the airflow
>would have to go down, wouldn't it?
The golf ball part is easy. The dimples don't reduce drag, they
increase it.
The reason the ball goes further is that the spin of the ball drags air
(using
this increased drag) over the ball in such a way that it increases lift.
It stays
in the air longer and that's why it goes further.
There is, however, a school of thought that says a very slightly
roughened
surface has less drag than a smooth one. The reason for this, they say,
is
that the slight roughness creates a very thin boundary layer of
turbulent air
which causes less drag than a smooth surface.
My hunch is that if there is a difference between a smooth surface and a
slightly rough one, it is a very small difference.
- Paul Schelling
SchellinPM@corning.com
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:37 EDT