Moth on Foils: 30.31 knots (34.86 mph)

[Doug Lord]

Originally Posted by bistros

..... generally being Doug Lord for quite some time.

--
Bill

========================
Guilty!

[Doug Lord]

Excellent article on the Moth and Moth racing in the November/December 2009 Sailing World......

[Doug Lord]

From Scuttlebutt:

"Seahorse Sailor Of The Month
Last month's winner:

Bora Gulari (USA)
'All hail Borat! Now take a shower' - Joe Gibson; 'Here comes the Robbie Nash of sailing' - Chris Williams; 'Bora's da man!' - Geoff Ewenson; 'This man invented sailing, water, beer' - Duncan Owlsey; 'A great effort by a determined dude' - Trevor Baylis; 'We are enjoying watching you from Istanbul' - Sacit Ertug; 'Because... he's a good guy, he just broke 30kt, America needs some good news, did I mention he's a good guy!' - Cam McTavish. "

[Doug Lord]

Interesting experiments by "Dr. Lojz": http://drlojz.blogspot.com/2009/11/i...and-water.html

Like everything else, partial span foils have advantages and disadvantages. On the model they allowed thin foils with no chance of flap lockup due to flex of the foil. The flap ends can be subject to their own tip vortex increasing drag-it's a trade off like everything in design.


10 year old partial span flaps from aeroSKIFF/14 year old thin partial span foil from F3:

[Doug Lord]

Gulari shot this video posted on you tube-interesting:

http://www.youtube.com/watch?v=qDpnXsAB1oc

[Jon Howes]

Good video. Notice the persistance of the ventilation bubble after the surface has been breached. An observation similar to this led to the Tomahawk foil concept since it suggested that the pumping losses due to maintenance of the ventilation cavity may not be quite as energy hungry as I had first anticipated.

Jon

[Doug Lord]

More video from youtube-shot by fmg:

http://www.youtube.com/watch?v=jr-b3ZIC_Uo


From youtube,shot by Gulari:

http://www.youtube.com/watch?v=CHWLk6JQ-DE

Paper on low RE# airfoils: http://www.ace.gatech.edu/experiment...nal_report.pdf

Interesting foilkayak video-initially used John Ilett(Moth) foils: http://www.youtube.com/watch?v=uO54ZvDwt18


Very interesting thread on SA-particularly post 89 on: http://forums.sailinganarchy.com/ind...ic=98777&st=75

Gulari: " i like black and white. "

[ancient kayaker]

Did Dr. Lotz mean the temperature of 15 deg C was too hot or too cold for sailing?

I would have thought winglets would have been a simpler and more efficient method of reducing wingtip vortices than changing the tip profile. Also, I have only seen winglets on foils once and they were pointing up: is there a reason for that? I always assumed the reason they point up on aircraft was to clear the ground for tackoff and landing; I suspect they would be at leaast as efficient pointing down on a hydrofoil and they would then keep the vortices further from the surface.

[Doug Lord]

This appears to be a really good idea for flaps that are not full span-from Primoz blog with his permission:

[ancient kayaker]

Would a full-width flap achieve the same result?