15 Nov 2006 08:11:47
Rob
Today kayaks, tomorrow racing shells...?

Check this out!

http://www.foilkayak.com/


In case anyone is unfamiliar with what's going on
here, the foil (IE airfoil, like an airplane wing) is
mounted horizontally underneath the hull, creating
more lift than I would have thought possible.



15 Nov 2006 11:26:47
Kieran
Re: Today kayaks, tomorrow racing shells...?

Rob wrote:
> Check this out!
>
> http://www.foilkayak.com/
>
>
> In case anyone is unfamiliar with what's going on
> here, the foil (IE airfoil, like an airplane wing) is
> mounted horizontally underneath the hull, creating
> more lift than I would have thought possible.
>

This was discussed a year ago in this thread (among others)...

http://tinyurl.com/wjgcp

BTW, it's a hydrofoil, not an airfoil, when used underwater. :-)

Hydrofoils can develop enormous amounts of force, thanks to the density
(among other things) of water. 150 years ago, people didn't think
airfoils could support much weight either... look at the 747.

Hydrofoils can support boats much larger and heavier than a carbon kayak
with one person aboard... try a massive warship:
http://en.wikipedia.org/wiki/Image:Fhe400.jpg

-KC


16 Nov 2006 14:48:15
Chris Kerr
Re: Today kayaks, tomorrow racing shells...?

The FISA rules specifically state that you must use a "displacement boat",
so you couldn't race in one, but it might be quite fun for training or
recreation. I wonder if the rigger bolts on a standard racing shell would
be strong enough to take a custom hydrofoil attachment...?

Rob wrote:

> Check this out!
>
> http://www.foilkayak.com/
>
>
> In case anyone is unfamiliar with what's going on
> here, the foil (IE airfoil, like an airplane wing) is
> mounted horizontally underneath the hull, creating
> more lift than I would have thought possible.



16 Nov 2006 11:28:50
Kieran
Re: Today kayaks, tomorrow racing shells...?

Chris Kerr wrote:
> The FISA rules specifically state that you must use a "displacement boat",
> so you couldn't race in one, but it might be quite fun for training or
> recreation. I wonder if the rigger bolts on a standard racing shell would
> be strong enough to take a custom hydrofoil attachment...?

The cyclic nature of rowing would make a hydrofoil based rowing boat a
very interesting venture: every recovery your hull would come back down
to (or close to) the water, and the hull would rise again during the
power phase. This would make keeping your blades buried during the
drive as hull velocity increased toward the release, quite challenging.

It'd be fun to try though!

-Kieran

>
> Rob wrote:
>
>> Check this out!
>>
>> http://www.foilkayak.com/
>>
>>
>> In case anyone is unfamiliar with what's going on
>> here, the foil (IE airfoil, like an airplane wing) is
>> mounted horizontally underneath the hull, creating
>> more lift than I would have thought possible.
>


16 Nov 2006 08:45:40
Rob
Re: Today kayaks, tomorrow racing shells...?

I sent the link to a lot of my friends and you may be interested in
some of the responses--including a link to a very cool clip of a foiled
sailboat at the bottom here:

<<<
I designed a solution a couple of years ago so I could kick Slocum's
ass and then discovered it is illegal in FISA. It can be done and
should result in 2-3x speed with less effort. The design would be a
foil under each rigger and a foil forward and aft. It would give the
fast-twitchers a much better chance.
Let me know if you guys want to build one.
Leathem
>>>

<<<
Ah, but CPR will allow them, and which would you rather have, some FISA
medal any Nancy-boy can win, or a victory in the greatest race ever?
While you're at it, why not build it sliding rigger so not so much
weight is sliding around...

What about rough water, would that cause a problem?

Christopher R. (Tiff) Wood
>>>

(CPR = Corvallis to Portland [Oregon] Row, early June, 115 miles over
two days with some current, the Ironman of rowing.)

<<<<
I am not as confident as Leathem is that a foil borne rowing shell
could be built that could go any distance. Notice the kayakers spm and
power output to sustain 'flying' (he goes what, about 200m?). Surely a
sliding rigger would have to be used because the movement of the center
of gravity when foil-borne would be a major issue. The other issue is
the cyclic nature of the rowing stroke, half the time there is no power
being applied no matter how you define the propulsive phase of the
stroke. This would be worst trying to get started. I do think that if
you got all the factors right it could be possible to go a short
distance, but I seriously doubt 2k. This would be a new way to equalize
heavy and light weights though as I have a hard time seeing a 90kg
rower able to 'get it up and keep it up.' Diet time Roman.

Best,
Paul
>>>>>

(Paul Fuchs, record holder for the single at the Head of the Charles)

<<<
Paul's right, there are issues that need to be addressed. Having used
a number of foil devices I have learned that:

-they give you an incredibly stable platform

-can be propelled successfully with intermittent power

-can be designed to lift with very low speeds and carry heavy payloads
(there's hope for you Roman), the tradeoff being ultimate performance

-once flying the power requirement to keep flying is substantially less
ie: starting hard and settling in

Ultimately it has be tried and debugged.
>>>>

<<<<
To digress a bit, for those of you who can tolerate sailing as a
diversion, it would still be on topic to show you this site of
foil-borne "Moth" sailboats. I gives you an idea of what can be done.
Don't be fooled, these guys really know what they are doing. While all
of the videos on the site are good, it is true that the 11mb is worth
it.

Have fun living vicariously: http://moth.iointegration.com/VideoSP.htm

Paul Fuchs
>>>>>



17 Nov 2006 00:52:45
Re: Today kayaks, tomorrow racing shells...?


Kieran wrote:
> Chris Kerr wrote:
> > The FISA rules specifically state that you must use a "displacement boat",
> > so you couldn't race in one, but it might be quite fun for training or
> > recreation. I wonder if the rigger bolts on a standard racing shell would
> > be strong enough to take a custom hydrofoil attachment...?
>
> The cyclic nature of rowing would make a hydrofoil based rowing boat a
> very interesting venture: every recovery your hull would come back down
> to (or close to) the water, and the hull would rise again during the
> power phase. This would make keeping your blades buried during the
> drive as hull velocity increased toward the release, quite challenging.
>
> It'd be fun to try though!
>
> -Kieran

As mentioned in the thread linked above, James Grogono built one at
Marlow. It is described in the book "Icarus - The boat that flies".
Steve Redgrave trialled it and had great problems getting it
"airborne". As you say, the boat rose and fell by about 6 inches each
stroke, so was very difficult to scull.

Kit



20 Nov 2006 12:13:38
Mike Sullivan
Re: Today kayaks, tomorrow racing shells...?


"Kieran" <kc_news@sonic.net > wrote in message
news:eji3k2$qlg$2@prometheus.acsu.buffalo.edu...
> Chris Kerr wrote:
>> The FISA rules specifically state that you must use a "displacement
>> boat",
>> so you couldn't race in one, but it might be quite fun for training or
>> recreation. I wonder if the rigger bolts on a standard racing shell would
>> be strong enough to take a custom hydrofoil attachment...?
>
> The cyclic nature of rowing would make a hydrofoil based rowing boat a
> very interesting venture: every recovery your hull would come back down to
> (or close to) the water, and the hull would rise again during the power
> phase. This would make keeping your blades buried during the drive as
> hull velocity increased toward the release, quite challenging.
>
> It'd be fun to try though!

Think about how the height changes though. I'd think that that would
be as significant as the hull speed changes.




20 Nov 2006 16:11:49
Kieran
Re: Today kayaks, tomorrow racing shells...?

Mike Sullivan wrote:
> "Kieran" <kc_news@sonic.net> wrote in message
> news:eji3k2$qlg$2@prometheus.acsu.buffalo.edu...
>> Chris Kerr wrote:
>>> The FISA rules specifically state that you must use a "displacement
>>> boat",
>>> so you couldn't race in one, but it might be quite fun for training or
>>> recreation. I wonder if the rigger bolts on a standard racing shell would
>>> be strong enough to take a custom hydrofoil attachment...?
>> The cyclic nature of rowing would make a hydrofoil based rowing boat a
>> very interesting venture: every recovery your hull would come back down to
>> (or close to) the water, and the hull would rise again during the power
>> phase. This would make keeping your blades buried during the drive as
>> hull velocity increased toward the release, quite challenging.
>>
>> It'd be fun to try though!
>
> Think about how the height changes though. I'd think that that would
> be as significant as the hull speed changes.
>
>
Uhhh... my point exactly. Sorry if that wasn't clear.

-KC


20 Nov 2006 21:55:26
Carl Douglas
Re: Today kayaks, tomorrow racing shells...?

Kieran wrote:
> Mike Sullivan wrote:
>
>> "Kieran" <kc_news@sonic.net> wrote in message
>> news:eji3k2$qlg$2@prometheus.acsu.buffalo.edu...
>>
>>> Chris Kerr wrote:
>>>
>>>> The FISA rules specifically state that you must use a "displacement
>>>> boat",
>>>> so you couldn't race in one, but it might be quite fun for training or
>>>> recreation. I wonder if the rigger bolts on a standard racing shell
>>>> would
>>>> be strong enough to take a custom hydrofoil attachment...?
>>>
>>> The cyclic nature of rowing would make a hydrofoil based rowing boat
>>> a very interesting venture: every recovery your hull would come back
>>> down to (or close to) the water, and the hull would rise again during
>>> the power phase. This would make keeping your blades buried during
>>> the drive as hull velocity increased toward the release, quite
>>> challenging.
>>>
>>> It'd be fun to try though!
>>
>>
>> Think about how the height changes though. I'd think that that would
>> be as significant as the hull speed changes.
>>
> Uhhh... my point exactly. Sorry if that wasn't clear.
>
> -KC

This need only be a problem if we assume fixed foil geometry. However,
it is perfectly possible to devise foils which are self-trimming so as
to provide constant lift over a useful range of boat speeds.

This has not yet been done, AFAIK, but it could be done. Might give a
very flat, or even inverse, relationship between drag & velocity.

Cheers -
Carl

--
Carl Douglas Racing Shells -
Fine Small-Boats/AeRoWing low-drag Riggers/Advanced Accessories
Write: The Boathouse, Timsway, Chertsey Lane, Staines TW18 3JY, UK
Email: carl@carldouglas.co.uk Tel: +44(0)1784-456344 Fax: -466550
URLs: www.carldouglas.co.uk (boats) & www.aerowing.co.uk (riggers)


21 Nov 2006 04:43:56
Leo
Re: Today kayaks, tomorrow racing shells...?


Rob wrote:
> Check this out!
>
> http://www.foilkayak.com/
>
>
> In case anyone is unfamiliar with what's going on
> here, the foil (IE airfoil, like an airplane wing) is
> mounted horizontally underneath the hull, creating
> more lift than I would have thought possible.

A pommie bastard studied this about 20 years ago. His conclusion was
that world-class athletes might just be able to get the shell to lift
out of the water, but that anyone below that level would not.

Millward, A., A study of the forces exerted by an oarsman and the
effect on boat speed, J. Sports Sciences, 5, pp 93-103, 1987.

(Cricket) seasons greetings to you all!