high lift low reynold's number two element wing sail

Hi all
i am investigating?!? the low reynold's number high lift airfoils section for a wing sail to be used on a C Class catamaran
the wing would work on a range of Rn from 600.000 to 2.000.000
and at angles varying from 0 to about 10-12°
the area is 28 m2 nd should provide a range of maximum lift between 170Kg (upwind course) to 250 Kg (ownwind course)
the only limit i see at the moment are the maximum span fixed at 12m and the fact that for reason of lightness i should avoide high torsional loads on the main element from the flap
i believe that a 30% flap could be tolerated
section involved E421 and E 423
thanks in advance for the collaboration

best regards

Marco

 

[buzz41]

I am curious to know what the rules are restricting the sail, mast, etc. for a class such as this. This might help to get more of the whole picture for the sail design.

I take it, the mainsail/wing would be symetrical and use a flap for camber?

 

the only limit of wing are that it has to be at maximum 300 feet2
the catamaran is long 25feet and larg 14
i forget to specify the wing preferred assembly
it will be a true asymmetrical wing pivoting at its center on a short mast on this model
\ ___ /
I\ I /I
at left wing an one side at the center wing pivoting at right wing on the other side
the I is the short mast

the flap should be on the style of junker flap as fowler flap doesn't guarantee to be turned upward to reduce the lift of the wing
this would began at wind speed of about 12-15 knots
these catamarans are capable to reach a boat speed from 2.2 to 3 times the wind speed in certain condition
hope i have been sufficintly clear

ciao

Marco

 

[WKTaylor]

Marco Failla...

go to:

http://www.AIAA.org

[store]

and get the inexpensive book:

"Saillons and Fliptackers" ISBN: 0-930403-65-7

Excellent book on high-speed sail-design concepts. Regards, Wil Taylor

 

[Basiliscus]

Ross, James C., "Aerodynamic Design of a Rigid-Wing Sail for a C-Class Catamaran," AIAA/SNAME SailTech '89 Conference, Stanford, CA, October 14-15, 1989.

"In order to take advantage of advances in airfoil technology, a tilting cambered wing sail was developed for use on the C-Class catamaran 'Wingmill'. Benefits of the new sail are reduced profile drag and increased maximum lift capability. The process used in designing the sail is described as well as analyses performed to assess its performance in the operating environment. Although the boat was built and tested in time, it was unable to compete in the 1989 Little America's Cup challenge in Melbourne because of severe damage sustained prior to the first race. In sailing trials, however, the boat performed well and apperaed to be competitive with the defending boat, 'Edge II'."