A-symmetrical

[san.dam]

Someone has ideas regarding families of asymmetrical foil sections,having his first third(or fourth) symmetrical? Substantially I mean the leading edge aft zone symmetrical...
Thanks for

[tspeer]

What are the requirements?
- purpose
- chord size
- speed range
- minimum & maximum loading per area
- minimum thickness for structural considerations
etc.

[san.dam]

... then you want to know all about the project, and curiosity kill the cat...(its for joke..)
Think at a 0.5m chord lenght,8 to 12% thickness and a range of Rn in field 10^6
I need a high Cl, but with imposition of symmetrical leading edge zone.

[tspeer]

You'll need to use something like XFOIL to design a custom section. Since you won't talk about the specific requirements, it's not possible to make a more concrete recommendation.

That general description could be done with a flapped symmetrical section. Sections for keels with flaps are designed these days to have a smooth contour on the suction side with the flap deflected. This leads to a modest crease in the contour on the pressure side or when not deflected, resulting in a small separation bubble. But the drag penalty from it may be acceptable if the increase in max lift with flap deflection allows the area to be reduced.

See:
http://www.heymanyachtdesign.com/in3a.html
http://www.esotec.co.nz/condorkeel/Html/hydro2D_F.html

[san.dam]

It would be a variable section foil,really asymmetrical (and not flap deflected) for port and starboard,and neutral in course downwind.
A drastic reduction of area is expected from this,if we can double the lift coeff.(optimistic)
Thanks Tom,it seems more and more clearly that the "families" doesnt exist..and need to calculate a custom foil section.