Rigs and Rigging Weight vs Drag?

Discussion in 'Sailboats' started by RHough, Nov 28, 2006.


To increase performance of a rig, is it more important to:

Poll closed Feb 26, 2007.
  1. Reduce the Drag of the rig.

    5 vote(s)
  2. Reduce the Weight Aloft.

    1 vote(s)
  3. It Depends. (Classic NA answer) :)

    7 vote(s)
  4. Don't know

    3 vote(s)
  5. Who Cares?

    1 vote(s)
Multiple votes are allowed.
  1. Paul Scott
    Joined: Sep 2004
    Posts: 307
    Likes: 8, Points: 18, Legacy Rep: 84
    Location: San Juan Island, Washington

    Paul Scott Senior Member

    Some questions I'm pursuing concerning the large diameter mast in the middle (ish) of the weather side of the sail:

    -is less drag than a skinnier mast with shrouds? (I know LFH experimented with this when he was working for Starling Burgess and found, much to their surprise that shrouds were less drag, but I like to believe in Munk's biplane theory too :p)

    -aero testing done on windmill blades show that a round support welded to the windward side of the blade was superior to everything but a naca 0012, and astonishingly close to that. Skandia Lab project.

    -whether the bigger mast might help establish some circulation around the mast/sail cell, and give a bit of lift to the sail, whether a lug rig, or jib. I'm not totally sure how to measure this in my garage.

    -how much drag reduction an epp wing section (like 6"-8" chord) might give, wrapped around the mast, as well as circulation, if I can think of easy, simple, and light control to introduce some (is reduced drag for the mast even a good idea in this array?)

    -could a large section unstayed mast offer better strength/weight/drag than a stayed mast

    A bit more apropos to the thread, I hope. And Brian, the Skandia experiments showed a jib in front of a round support (like some traditional windmill blade) was draggier than most. (Flow perturbations off the trailing edge?) But most of the other approaches require an unstayed mast. Trade offs! Given all that, the idea of slowing down flow on the high pressure side of a curved plate with a thick unstayed mast (better re regime?) is still kind of intriguing. What the flow in between the mast and sail might do to the overall system?:?:

    The Skandia wind tunnel runs (IIRR) were conducted around researching low tech windmills in less developed countries. Like steel plates welded to rod, or fabric, line, and rod. Interesting stuff.
  2. Paul Scott
    Joined: Sep 2004
    Posts: 307
    Likes: 8, Points: 18, Legacy Rep: 84
    Location: San Juan Island, Washington

    Paul Scott Senior Member

    It might have been Sandia labs. At any rate my link doesn't work.

  3. brian eiland
    Joined: Jun 2002
    Posts: 4,965
    Likes: 188, Points: 73, Legacy Rep: 1903
    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.