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Post Reply | Page <1 7891011> |
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fudheid
Far too distracted from work Joined: 21 Apr 11 Location: 51.53 N 01.28 E Online Status: Offline Posts: 241 |
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Quote Reply
Topic: Technical protest Posted: 19 Nov 19 at 4:48pm |
So this fence isn't producing lift? It isn't shaped to change the flow of water around the foil? Canting / lifting the rudder doesn't increase our decrease the angle the fence makes?
Having a fence doesn't enhance the performance of the foil in certain conditions, i.e. it stops ventilation, stopping the stalling of the higher aspect foil? If I make this fence larger when does it become a non allowable wing? |
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Cheers you
only me from over the sea...... |
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423zero
Really should get out more Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3406 |
Post Options Quote Reply Posted: 19 Nov 19 at 5:06pm |
Can't see it clearly on phone, but it looks like it also as a reduced chord ?
If the manufacturer designed blade purely to reduce suction and you attempt to make it into a foil ! Speaks for itself. |
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Robert
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fudheid
Far too distracted from work Joined: 21 Apr 11 Location: 51.53 N 01.28 E Online Status: Offline Posts: 241 |
Post Options Quote Reply Posted: 19 Nov 19 at 5:11pm |
Not attempting to make it a foil. If it reduces suction is that no creating lift? |
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Cheers you
only me from over the sea...... |
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fudheid
Far too distracted from work Joined: 21 Apr 11 Location: 51.53 N 01.28 E Online Status: Offline Posts: 241 |
Post Options Quote Reply Posted: 19 Nov 19 at 5:15pm |
That's too say, if this fence is creating any lift around it then it is a wing it contrivance under the definitions of the ERS/rule?
IF NOT. then how much wider/ bigger can it get before the lift it generates is a wing or contrivance? |
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Cheers you
only me from over the sea...... |
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Noah
Really should get out more Joined: 29 Dec 04 Location: United Kingdom Online Status: Offline Posts: 611 |
Post Options Quote Reply Posted: 19 Nov 19 at 5:32pm |
Sorry, 432Zero, I disagree. If the purpose of the fence is reduce cavitation it is, by definition a performance enhancement by virtue of the fact that the boat is easier to steer / more stable at high speed.
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Nick
D-Zero 316 |
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6649 |
Post Options Quote Reply Posted: 19 Nov 19 at 5:52pm |
In practical terms there will be a gap between a fence that is bigger than it needs be to do the job, and a foil that's too small and too low aspect ratio to do anything significant. The difference will be obvious. But in any case any control to accurately change the angle of incidence of the foil on the water would be a dead giveaway. |
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Sam.Spoons
Really should get out more Joined: 07 Mar 12 Location: Manchester UK Online Status: Offline Posts: 3398 |
Post Options Quote Reply Posted: 19 Nov 19 at 6:14pm |
Pedant alert (sorry) Ventilation, not cavitation, cavitation doesn't happen at dinghy speeds (not even, I think, foiling Moth speeds).
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Spice 346 "Flat Broke"
Blaze 671 "supersonic soap dish" |
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423zero
Really should get out more Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3406 |
Post Options Quote Reply Posted: 19 Nov 19 at 6:43pm |
Fence is a performance enhancing device like,
Self bailers, they enable you to empty boat quicker than someone without. Mast head float, stops you turtling, quicker recovery. Duck under, stops you throttling yourself with mainsheet. Hiking straps, allows you to lean further without falling in. etc etc etc where do you draw the line ? |
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Robert
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gbrspratt
Posting king Joined: 26 Sep 11 Location: Felixstowe Online Status: Offline Posts: 170 |
Post Options Quote Reply Posted: 19 Nov 19 at 6:48pm |
Why do you need to draw a line? As you say they all improve performance? I don't really get your point. The point about the fence is how it fits in the rules?
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423zero
Really should get out more Joined: 08 Jan 15 Location: United Kingdom Online Status: Offline Posts: 3406 |
Post Options Quote Reply Posted: 19 Nov 19 at 7:54pm |
Lost train of thoughts now Think it was in relation to adjustable wing and fence in relation to Merlin ruling.
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Robert
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