theres an interesting chapter in "High Performance Sailing" by Frank Bethwaite who was a friggin genius with weather and fluid dynamics. From their testing he found that there was a 30-some % drag reduction on foils when polished vs. just sanded. There was not much difference when compared over a l...

Hi tim, Tell me more about your vibration issue, if you would. Is it something you hear... or feel? If it’s tonal, you could record the sound to confirm the dominant frequency. I doubt you have access to accelerometers, but they would confirm frequency content, as well. Can you confirm the vibration...

The "golf cart" with wings has pretty much signaled the end of this thread. Moving on. ..maybe. Conceptually, a T foil heeled does look like a V foil. So, is it possible that developing a surface piercing foil is more related to a change in technique than hardware? Heave stability would be achieved ...

If the original lam was with west and allowed to cure you may have contamination from amine blush

Hello,....... So a hypothetically speaking and made as simple as I can for an example of this. Sym wing profiles front and back. F wing mounted on fuse 0° and flys at + 7° A O A so r Wing would be mounted on fuse at -7° A O A to be at 0° when the F wing flys. Would this not mean that r wing has the...

perhaps retractable flaps as seen on commercial airliners would meet the criteria for this exercise? Hadn't thought of that...variable chord. Interesting idea. Or variable profile (thickness) foils, which get thinner as speed increases... variable chord.. your right. the way i described it does ind...

I'm a bit surprised that there is no mention of techniques used by more 'mature' foil designs. specifically adjustable flaps used for both pitch and heave control on the moth. perhaps retractable flaps as seen on commercial airliners would meet the criteria for this exercise? in contrast to a device...

carbonic boats has an article discussing different approaches to obtain passive heave stability in foiling boats. http://carbonicboats.blogspot.com/2013/06/alphabet-soup.html specifically they talk about potential benefits of acute "L" or "V" foils that initiate reduced lift due to increase leeway o...

now both you guys are confusin me. are we talking anhedral or winglets ? i see them as two distinctly different parameters. JS simply meant that the wingtip (or any lift producing device) would suck air if it traveled too close to the water surface. winglets as designed by the big kids at boeing are...

Anhedral add about 10% efficiency . I am almost sure this is simply not true, but FOR SURE curved wings add yaw stability! Where do you get this idea from may I ask? 10% is HUGE, so prove it please! R H proof may be difficult, perhaps considering a 'loose' definition of efficiency i could offer a p...