View Single Post
  #7   Report Post  
posted to rec.boats.building
Bruce in Bangkok[_7_] Bruce in Bangkok[_7_] is offline
external usenet poster
 
First recorded activity by BoatBanter: Apr 2008
Posts: 257
Default Underwater surface finish

On Sun, 17 Aug 2008 14:50:12 -0400, "Glenn Ashmore"
wrote:

Just reading up on golf ball dimples They evidently create a thin layer of
turbulence that keeps the laminar flow from breaking away longer reducing
the turbulent area behind the ball. Discounting the Magnus effect because
a hull does not (normally) spin, the result is less drag.

That said, it seems to follow that dimples on the mast would hold the air
flow around it further aft reducing the turbulence on the luff of the main.
Probably not much but then the big racers cut their toothbrushes in half...
:-)



The guy in the next slip to me is a serious racer, and pretty
successful at it. He talks about "seconds per mile" and I assume that
if a "golf ball" finnish would actually increase speed he would be
spending every Sunday punching dings in his hull.

Since he isn;t I suspect that dimples probably don;t effect the speed
of a boat hull.

However, boats, particularly submarines, operate in very similar
conditions as a competitive swimmer and if the new suits give them a
5% decrease in drag then why not boats? Or perhaps, why them and not
boats?


Bruce-in-Bangkok
(correct Address is bpaige125atgmaildotcom)