[Rhodes22-list] Swing Keel Problem

[ROGER PIHLAJA]

Jeff,

Close hauled, I would think the extra foot of draft increases the effective aspect ratio of the keel, which makes it a more efficient hydrofoil at generating lift to go to windward.  It also lowers the center of lateral resistance (CLR) to help prevent heeling.  Together, these two factors should overcome the increased drag from the opening in the centerboard well.  Downwind, you don’t need the lift, so closing up the centerboard/well  gap decreases turbulence and drag, which should be faster.  So, in your mind, what is the “correct” position?

Roger Pihlaja
S/V Dynamic Equilibrium (a 1976 model with a proper high aspect ratio centerboard)
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From: Jeff Smith Photo<mailto:jeffsmithphoto at gmail.com>
Sent: Monday, August 23, 2021 7:18 PM
To: rhodes22-list at rhodes22.org<mailto:rhodes22-list at rhodes22.org>
Subject: [Rhodes22-list] Swing Keel Problem

A while after I bought (now) Radiant and hauled her with a travel lift, to
put her on jackstands to give her a new bottom, I noticed the way the
diamond keel haul line was knotted in the cockpit allowed about an extra
foot of draft. But it also introduced a hollow section of diamond board
below the keel. As a Recovering Racer I tried to figger which would be
faster up wind: more depth or less hollow turbulence with the board on it's
lines? I opted (which is easily changed) for the board in the "correct"
position.  Any thoughts?

Best Regards
Jeff Smith
www.http://JeffSmithPhoto.Net<http://www.http:/JeffSmithPhoto.Net>
732-236-1368
Radiant
Atlantic Highlands, NJ