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sargesail View Drop Down
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    Posted: 03 Sep 14 at 8:39pm
Originally posted by jeffers

Originally posted by washy

Originally posted by jeffers


Originally posted by Medway Maniac

Looks as though it was feeling nice... till those trees got you!

The wind was far enough round that they didn't really affect that much and there was a gybe away from them just out of shot. Perhaps a tad too much kicker maybe looking at the leech...


Top tell tale is flying at least so apparently not stalled?

Leech looks a little hooked though lower down...just something to bear in mind for future. Always hard to see when you are in the boat though.

Interesting - you could cure the hook by putting a touch of outhaul back on.  That is a lower leech problem.  But you'd lose power.
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Daniel Holman View Drop Down
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Post Options Post Options   Quote Daniel Holman Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 14 at 9:26pm
You want all the power reaching - drag is pulling you forwards!

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sargesail View Drop Down
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Post Options Post Options   Quote sargesail Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 14 at 9:44pm
Don't disagree with that Dan, but it looks to me like you'd end up with an awfully loose upper leach to cure that perceived hook in the lower leach.
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Post Options Post Options   Quote Daniel Holman Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 14 at 9:59pm
To my untrained eye the set looks spot on on Jeffers sail. 
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Post Options Post Options   Quote Koops Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 14 at 10:20pm
No hint of humour Dan so an intriguing statement!  For the drag component of the aero force (normal to chord of sail) to be pulling boat forwards, to my mind that implies that either the sail is sheeted out so that it is forward of the mast (forward quadrant) with flow from luff to leech, or vice-versa I.e. Apparent wind vector in aft quadrant. That is not reaching though? Please put me out of my misery and explain my misunderstanding ;-)
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 14 at 10:44pm
Drag is normal to the apparent wind, not the sail, so if the wind is (even slightly) from behind then drag has a forward component.
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Post Options Post Options   Quote Koops Quote  Post ReplyReply Direct Link To This Post Posted: 03 Sep 14 at 11:15pm
Doh...I meant lift is normal to and drag parallel to chord of sail, but I don't believe that drag is conventionally defined as normal to the apparent wind, hence my confusion about Dan's statement. I'm sure that aerodynamicists could enlighten us :-). Perhaps yachting world uses a different convention from aerospace world?
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 04 Sep 14 at 7:29am
Oops, sorry I meant lift is normal to the apparent wind and drag is parallel. Definitely to the apparent wind though, not the sail.
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Rupert View Drop Down
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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 04 Sep 14 at 8:42am
If it is confusing even you lot, I'll just keep letting the sail out till it isn't quite flapping and the kicker off till it looks about right...
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Post Options Post Options   Quote kneewrecker Quote  Post ReplyReply Direct Link To This Post Posted: 04 Sep 14 at 9:49am
do you let the kicker off then Rupert?  Ah, that explains my off wind speed all these years...
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