Recent content by pschwenn

  1. pschwenn

    Pics That Get You...

  2. pschwenn

    where in the world

    Some monster tide zone, where the rich have castles'n'stuff, but are civilized and astute: with marvelous fun dinghies, instead of Hinckley Picnic Boats. Lotta mussels. Ancient solar observatories on the estuary (now with its own railroad.) It's not where I'm from.
  3. pschwenn

    Better sailing performance on a liveaboard cruiser?

    Two areas stand out to me. 2. Aero hamper: you have (too much) running rigging hamper, and some in the transom area: gizmos, aerials, ... that you could reduce. Think of your deck and space above it as an airplane's fuselage. 1. Casual sailors and many cruisers, even some racers, believe that...
  4. pschwenn

    Perry Sliver Class Day Sailor

    Anarchists, Calling this a hand drawing is not entirely forthright. It is hand-drawing over a hull-shape, rudder and keel from the attached design [via the URL below - due to its size]. Note how the portlights do not follow the sheer line, the original rudder and keel outlines have not been...
  5. pschwenn

    Cruising boats that plane

    There are very few left (none with cabins).  If I were a better carpenter and had the "conservator" gene, mine would have lasted more than 35 years.  If you visit Australia you might try the one shown ("old" looks better to me, and drier), or the more common Flying 15.
  6. pschwenn

    how to add sail area to an unstayed kat ketch

    You could increase the area, making little or no change in center of effort and reduce induced drag by about 1/2 (that's a lot) with sails as is (or newly "as is") by extending the foot of the each sail down to deck level through the wishbones.  The sail foot need not rest right on the deck but...
  7. pschwenn

    Cruising boats that plane

    Here is a fairly early planing cruising boat, Capricia II.  A one-off cruising variation, LOA 35', of the Uffa Fox's Flying 25.  Built cold-molded mahogany/resorcinol 1/2" in 5 layers, in 1968, moored off Dinard until about 1989, then in the Chesapeake Bay with a taller rig for the light air ...
  8. pschwenn

    Perry Sliver Class Day Sailor

    SemiSalt For a boat where the struts obstruct crew passing fore and aft, which is a significant danger, perhaps a solution is as follows: free the struts from the mast and rotate them outboard to 45 degrees; anchor them by cable down to a reinforced point at the rail; cable their upper ends to...
  9. pschwenn

    Return to Winged Keels

    DDW "Lift is drag" may be disturbing, and "Lift develops from a phenomenon initially causing only drag" is more accurate (and way long), however -  The reason drag is taken as primary, when initially examining or re-examining a flow phenomenon, is that lift takes time to initiate and develop...
  10. pschwenn

    Return to Winged Keels

    It would be unusual to be able to directly measure what you would lik         {oops]
  11. pschwenn

    Return to Winged Keels

    That's one more reason not to focus on them.
  12. pschwenn

    Return to Winged Keels

    Weightless, (I promise never to post on this again). I would agree with you that on an individual sail or keel or any more or less wing-like part, the conventional definition of lift and drag may be useful at some level.  But can obscure what resolutions to make of the net force into forces...
  13. pschwenn

    Return to Winged Keels

    DDW, The 1/4 chord line convention and the associated NA convention for the Lift and Drag vectors were introduced to simplify the description of the real force distributions.  They are conventions without a physical basis other than the foil geometry.  I don't think we're back and forth about...
  14. pschwenn

    Return to Winged Keels

    Weightless, They are usually unambiguously for us, but that unambiguous definition depends on the intent of the vehicle and on the situation, which a formal system like a computer program cannot determine by itself however unambiguous the definition is.  When the intent or requirement changes...
  15. pschwenn

    Return to Winged Keels

    DDW, I'm not saying that there is only drag, or that there is no lift; but that components of the overall forces don't have inherent properties of lift, or drag. Before resolving the overall force vector into lift and drag, you need to know (and you usually do) what the intent is in the...
Top