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brian eiland · 06-13-2006, 10:30 AM

How about a match race between two very different superyachts, one with a sloop rig, and the other with a 'modern' square rig.

The World's Three Largest
http://www.yachtforums.com/forums/8815-post5.html

I've had a considerable interest in the aerodynamics of sailing rigs, particularly in defending my unusual 'single-masted ketch rig'
So I was particularly interested in this diary posting:

...from the crew's diary...
"There have been many questions about our sailing numbers. In looking through these data, we discovered that our best VMG occurs at around 35 degrees apparent. With full sails set, we may get pretty close to the 30 degrees predicted by the computer/wind tunnel tests. Another interesting aspect, is how the boat performance changes in gusts. Unlike essentially all other sail boats---except, perhaps the AeroRig--- which try to round-up in strong puffs, the Falcon with her DynaRig, simply accelerates, with no effect on the helm and no change in heading. There a number of reasons for this: the center of effort of the rig is relatively low; the keel is relatively long; but most important, there is no change in the shape of the sails. Other rigs tend for the boom to lift and the sail top to twist, which leads to an adverse change in the weather-helm."

I had made reference to the aero characteristics of this 'dyna-rig' in several other previous discussions:

Square Rig Pointing (some aero questions here)
http://boatdesign.net/forums/showthread.php?t=5991

Sail Aerodynamics
http://boatdesign.net/forums/showthread.php?t=457

So Jed White, I am very interested in your aero testing. And my grandest congradulations to Tom Perkins for having the insightfullness to conceive of, and see this project thru.

06-13-2006, 10:30 AM	#53
brian eiland Senior Member Join Date: Jul 2004 Location: Washington DC, Annapolis MD, Thailand Posts: 955	Sloop Rig verses Square Rig How about a match race between two very different superyachts, one with a sloop rig, and the other with a 'modern' square rig. The World's Three Largest http://www.yachtforums.com/forums/8815-post5.html I've had a considerable interest in the aerodynamics of sailing rigs, particularly in defending my unusual 'single-masted ketch rig' So I was particularly interested in this diary posting: ...from the crew's diary... "There have been many questions about our sailing numbers. In looking through these data, we discovered that our best VMG occurs at around 35 degrees apparent. With full sails set, we may get pretty close to the 30 degrees predicted by the computer/wind tunnel tests. Another interesting aspect, is how the boat performance changes in gusts. Unlike essentially all other sail boats---except, perhaps the AeroRig--- which try to round-up in strong puffs, the Falcon with her DynaRig, simply accelerates, with no effect on the helm and no change in heading. There a number of reasons for this: the center of effort of the rig is relatively low; the keel is relatively long; but most important, there is no change in the shape of the sails. Other rigs tend for the boom to lift and the sail top to twist, which leads to an adverse change in the weather-helm." I had made reference to the aero characteristics of this 'dyna-rig' in several other previous discussions: Square Rig Pointing (some aero questions here) http://boatdesign.net/forums/showthread.php?t=5991 Sail Aerodynamics http://boatdesign.net/forums/showthread.php?t=457 So Jed White, I am very interested in your aero testing. And my grandest congradulations to Tom Perkins for having the insightfullness to conceive of, and see this project thru.