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moondog
Since 15 Aug 2007
703 Posts
white salmon
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CGKA Member
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Fri Sep 06, 19 5:46 pm Foiling question for all you Hydrology engineers |
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In the good old days I would search out the undisturbed butter water on wave faces and behind the barges on my surf board. Now on my 633 foil when I hit these same surfaces I get this weird burble like the wing can't grab on to anything. It seems to me that foils prefer disturbed water. After 40 years as a pilot disturbed air meant turbulence. Our wings didn't like disturbed air. These hydro wings seem to prefer disturbed water! Any theories! _________________ moondog |
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eric
Since 13 Jan 2006
1831 Posts
XTreme Poster
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Fri Sep 06, 19 6:28 pm |
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The water behind a prop is heavily disturbed. |
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moondog
Since 15 Aug 2007
703 Posts
white salmon
Addicted
CGKA Member
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Fri Sep 06, 19 6:44 pm |
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The water behind the barge is disturbed probably 5-8 feet below the surface, but we are on the glassy section and my wing is buffeting like it wants to stall. As soon as I leave the glass everything returns to normal. _________________ moondog |
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kassak
Since 18 May 2010
108 Posts
Stoked
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Fri Sep 06, 19 8:38 pm |
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My thoughts:
If you foil behind a boat you will also find that while the direct area in the prop wash is rough it’s rideable because the turbulence while high is random with respect to directionality. The area outer towards the wake is very inconsistent in ability to ride I believe owing to turbulence which has a consistent rotation and directionality which while not itself super stable in its presence is otherwise consistent with respects to its other attributes. It’s likely someone who knows their fluid dynamics is reading and thinking of a polite way to tell me I have no clue...
Steve |
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bwd
Since 04 Aug 2007
385 Posts
Obsessed
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Fri Sep 20, 19 5:46 pm |
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In surf dude terms i think the issue is the types of vortices you can see in underwater surf video shots where it looks like parallel ropes climbing up the wave face that end up dissolving into boils of white water ws the wave breaks.
These make stripes of up- and downgoing water just below the surface. A foil passing successively through these is going to feel it. |
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