needing help here ...

[ning]

hey there! i am an industrial design student in singapore. currently i am working on a human-powered transportation project. and i haf some enquiries on the hydrofoil theory.

ok here goes...

lets say i have a surfboard-like kind of board. and i attached a couple of hydrofoil fins on the bottom. then i get a guy of an average weight and height to kneel on top of it holding on to a conventional kayak pedals. and with the pedal, he paddles forward.

now my question is,

1. if he were to gain enough speed, will the 'sufboard-with-hydrofoils' be able to achieve a similar result as those hydrofoil boats and sailboats? in other words, will the board be able to rise up above the water, thus causing less drag and allowing the board to proceed faster?

2. and if it is possible, then what is the estimated speed that he needs to travel?

ya these are what i need to know. i am not any marine engineer, so i am pretty lost at this subject and hope to be able to get some answers from here. your help is very much appreciated! you can reply to this thread, or email me at f@rk.theinbox.org

ya thx alot and hope to get some replies soon!

yours truly,
ning

[ErikG]

I suggest that you check out the swedish "Trampofoil"
http://www.trampofoil.com

Other related stuff can be found here...
http://www.foils.org/human.htm


Good luck!

[ning]

hey thx alot... seen the site... cool stuff!

[Suede]

Eric...you look much younger today....;-)

Grattis !!!
Olle

[ErikG]

Eric...you look much younger today....;-)

Grattis !!!
Olle
Yeah I do don't I? :D [yummy]

[ning]

but hey... my problem is still not solved.
i was wondering if there will be problem on the initial of the craft. becos it will human-powered by a set of kayaking paddles.
and wat is the minimum speed that the craft have to attain in order to 'fly'?

ning

[NiklasL]

Sorry that I don't know for shure who or when:

I have read somewhere, about a group that tried a simular ting at least 10yrs ago. Maby from the book: "Grogano, James, ICARUS, the Boat That Flies, 1987"

They used a simular one-person boat as pictured and tried to paddle faster than a boat without hydrofoils.

The problem was to remain foilborne with low resistance hydrofoils (small lift area). This because of the nonconsistent propulsion that oars produce.

Their result was that it's not possible to go faster on foils in this boat type with one person and technology available at that time.


So if top speed is not the goal the i assume kayaking on foils (but with sweat involved) is a reality.

/Niklas Lundberg

[Raggi_Thor]

Maybe 10 years ago in the "world championship for pedal boats" the winner was a hydrofoil with two hulls (catamaran) for stability at lower speeds and one large foil under the rider and oone smaller in front. When the boat lifted out of the water a small "ski" in the front adjusted the front foiler. The whole thing would ride up and down, oscilating(?) a bit, but it stayed out of the water for severeal minutes, cruising at 10-15 knots! Propulsion was a large slow turning propeller.

[NiklasL]

No this one was oar propelled. Propeller is much better.

[Dutch Peter]

1. if he were to gain enough speed, will the 'sufboard-with-hydrofoils' be able to achieve a similar result as those hydrofoil boats and sailboats? in other words, will the board be able to rise up above the water, thus causing less drag and allowing the board to proceed faster?
Ning,

No, I don't think it can be done. The thrust is fluctuating too much and you'll have a stability problem as the thrust is alternating from side to side.
But proof me wrong!

[yipster]

No, I don't think it can be done with a draggy surfboard eighter. have a look at http://lancet.mit.edu/decavitator/ and using the search button above i'm sure there is more on this subject.

[Doug Lord]

You can fly on just two foils like the Moths do but using a kayak paddle,see:
http://www.foilkayak.com/
Also, use the resources of www.foils.org to help you understand what's happening and why.
I would doubt that a "surfboard" could be used because of it's relatively high paddling resistance but as you can see above a kayak sure can fly-quite nicely!
---------------------------
Also check this out:
http://neilprydemaui.com/itemDetails.php?id=48
Still two foils but only one strut....
==============================
For some detailed discussion of hydrofoils within the Moth class(THE pioneers in sailing) ,go here and click on message board and then hydrofoils:
http://www.moth.asn.au

[yipster]

Also check this out:
http://neilprydemaui.com/itemDetails.php?id=48
Still two foils but only one strut....
another: http://www.airchair.com/

[NiklasL]

That foilkayak is really mind boggling Dough!
It must be the new materials and cnc-accuracy that made it possible to be more effective than without foils!
Still sweat involved though =)