Hydrofoil assisted catamarans.

[BMcF]

Originally Posted by jack frost

Bmcf Do you have any Idea at all how much a hydro foil costs.

I found an interesting site where a guy was using old helecopter rotors. he said usually the rotors will not be replaced with out the old ones being returned. However the rotors are not wanted, they just dont want them to have old ones that could be used in any way.

Apparantly as shipping was expensive, the manufacturer said saw the boss off the end and post that. we will then ship you a new one.

Consiquently old rotors are available, as much as 2 feet in width and 15 feet or more long.

What I could not find on the web was a picture of a catamaran hydrofoil, Oh plenty of pictures of boats zooming about but nothing of a hydrofoil itself.

Its like that yellowfin drive plenty of graphs and hype and distant pictures.

How much does a hydrofoil cost?...er..what size foil, what size boat, how much lift, hull material? The foils under our trimaran (43' aluminum hull) cost about 16K$..they are billet aluminum foils, CNC machined.

The helo rotor idea sounds interesting..wonder what the foil section shape is?

-Bill

[Frosty]

I have located a Sikorsky rotor blade!!! Dont know if I have to pay for it yet or not --it is the NACA 0012 foil I think wich seems very similar to the one on airfoil web page that they suggest is low speed hight lift for bombers also!!.

It is also similar to the 747 and 767 aifoils.

I might just have a lttle go at sticking this on and see what happens.

Hey I got all the time in the world.

[Frosty]

Could some one please help me in a calculation . I was terrible at school and still am.
I have decided to use some "winglets" from 2 inch marine ply bolted to both dummy keels.

I have decided upon the NACA 63412 foil as this seems to be recomended in most places I have looked.
I only need an approximation of lift from these 2 winglets.

Size would be 4 feet span x18 inch chord ( if i want 12%) !!
There would be 2 of these.

So --48 x 18 = 864SQ inches per winglet X 2= 1728sq inches divided by 144 =12 SQ feet.

At 14 kts eerr can anybody take me further. Angle of attack no more than 5 degrees.????