SailNet Community - View Single Post - tacking angle
Thread: tacking angle
View Single Post
  #2  
Old 03-26-2007
Giulietta Giulietta is offline
.
 
Join Date: Nov 2006
Posts: 10,851
Thanks: 0
Thanked 4 Times in 2 Posts
Rep Power: 12
Giulietta is just really nice Giulietta is just really nice Giulietta is just really nice Giulietta is just really nice Giulietta is just really nice
here's a tricky question...yes and no..

Wind/air velocity change the amount of lift/pull/push on the sail. The faster the air passes thru the sail, the lower the depression created (according to Bernoulli's principle), the higher the pull, the higher you can point, (due to the reduction in the vectors), however, as the wind goes up you have to change sail shape, changing camber (bag), in order to prevent it from stalling / flaping, so you go back to where you were.

So yes, theoretically you should be able to reduce pointing angle, due to increase in relative airflow velocity, but in reallity you can't because of sail shape and boat speed.

Think of point angle as angle of attack on a wing of a plane, which is the angle created by relative airflow and incidence angle.

If you do its almost negligenciable.

NO is the answer in real life. If you want to reduce point angle you have to reduced the angle of attack, which can only be done by trimming sail, during construction of the boat, which dictated where and how sail travelers are located, and how much camber (bag) does your sail have.

Then, there is heel, as the wind picks up, the boat heels more, and by doing so, it increases wet surface on leeward, increasing drag, the sail inclines, looses efficiency due to decreased frontal area...bla bla bla....forget it...

NO

Last edited by Giulietta; 03-26-2007 at 02:22 PM.
Reply With Quote Share with Facebook