Re: [Paddlewise] Pro's and Con's of the "Swede Form"

-----Original Message-----
From: Matt Broze <mkayaks_at_oz.net>
To: 'Paddlewise' <paddlewise_at_lists.intelenet.net>
Date: May 29, 1999 7:23 PM
Subject: Re: [Paddlewise] Pro's and Con's of the "Swede Form"


(SNIP)

>I can't figure out what it is you are trying to say here. I don't know
about
>the point of creation but once the wave is created it should act like any
>other deep water wave (this is why I proposed a long hull with many waves
>along it as the model. There is water in those waves and it is going up
and
>down. As best as I can tell you are describing a higher speed regime with
no
>crests along the hull.

As I think about it this something comes to mind. The waves created travel
in the same direction as the hull. That means that the rotation at the
crest would be opposite the direction of travel. We know that the flow
along the hull travels from front to back from our flow experiments. But,
suppose the flow in the waves at the crest acts to retard the flow along
the hull thus increasing the potential energy and then in the troughs tends
to augment the flow because the trough motion acts in the same direction as
the hull flow. This satisfies the flow regime (faster in the troughs where
pressure decreases) slower in the crests (where pressure increases) even
though the flow in  the waves acts a distance from the hull and it also
satisfies the flow in the created waves.

An interesting thing about this comes to mind in that Leo Lazauskas (author
of the CFD program Michlet) says you cannot rely upon wave size predictions
close to the hull and perhaps this helps to explain why. Couple these
opposing flows with turbulent flow aft etc and you might get a real mess.

I think you have hit on something, Matt, that I had not thought of before.

Who says these things aren't productive. Glad you stuck to your guns on
this one, Matt.

Cheers,
John Winters
Redwing Designs
Specialists in Human Powered Watercraft
http://home.ican.net/~735769/





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