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fastest point of sail #191206
09/17/09 04:54 PM
09/17/09 04:54 PM
Joined: Sep 2007
Posts: 757
japan
erice Offline OP
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erice  Offline OP
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interesting polar on the new multi23 trimaran at

http://www.multi23.com.au/

click specifications and then the image at the bottom right

interesting in that it shows 7 different wind speeds and shows that a 90degree beam reach is the most efficient/ fastest in light winds up to 12nts

but as the wind speed climbs over 12nts the fastest point of sail moves off to the 130degree broad reach

less efficient but higher overall speed as presumably as all the buoyancy from a 3 bows is needed to keep the boat from digging in and pitchpoling

Last edited by erice; 09/17/09 04:57 PM.

eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294
-- Have You Seen This? --
Re: fastest point of sail [Re: erice] #191211
09/17/09 06:22 PM
09/17/09 06:22 PM
Joined: Nov 2005
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“an island in the Pacifi...
hobie1616 Offline
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“an island in the Pacifi...
Screaming reach!!


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Re: fastest point of sail [Re: erice] #191216
09/17/09 09:02 PM
09/17/09 09:02 PM
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Eastern NC, USA
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tshan Offline
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180 degrees from hobie1616; doesn't matter the relative wind direction. My opinion from his web presence, I am sure he is a nice guy in real life.

Sailing without him, I'd say beam to broad reach. Depends on sails available, hull shape......


Tom
Re: fastest point of sail [Re: erice] #191230
09/18/09 02:14 AM
09/18/09 02:14 AM
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Posts: 1,203
uk
TEAMVMG Offline
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yes, that could imply that the boat is bit of a cow on a beam reach in a breeze!


Paul

teamvmg.weebly.com
Re: fastest point of sail [Re: TEAMVMG] #191242
09/18/09 08:31 AM
09/18/09 08:31 AM
Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
Timbo Offline
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On a windy beam reach the lee ama is going to be underwater, slowing the boat down I would think. When you get to that point, I think it would be faster to bear away and use the added lift/support of all 3 hulls, and get all the people to the back of the boat!


Blade F16
#777
Re: fastest point of sail [Re: Timbo] #191259
09/18/09 10:23 AM
09/18/09 10:23 AM
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Naples, FL
waterbug_wpb Offline
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I would think any point of sail in the upright position would be fast.

I know my sails never worked very well in the inverted (underwater) position. Even with the spinnaker up. smile


Jay

Re: fastest point of sail [Re: waterbug_wpb] #191270
09/18/09 12:14 PM
09/18/09 12:14 PM
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tampa, fl
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ksurfer2 Offline
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....Then you're not playing the current efficiently!!!!


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Re: fastest point of sail [Re: ksurfer2] #191282
09/18/09 01:32 PM
09/18/09 01:32 PM
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Clermont, FL, USA
David Ingram Offline
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Haven't you heard of the fifth mode you bunch of donkies!

[Linked Image]

Last edited by David Ingram; 09/18/09 01:33 PM.

David Ingram
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Re: fastest point of sail [Re: David Ingram] #191337
09/19/09 08:41 AM
09/19/09 08:41 AM
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Palm Beach County
TheManShed Offline
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Aaarrrgggg....Multi 23 made in China and the Farrier we do everything best wankers --- can't wait to get back to work on the TMS-20 come on shoulder heal faster!


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Re: fastest point of sail [Re: ksurfer2] #191492
09/21/09 03:34 PM
09/21/09 03:34 PM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
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Originally Posted by ksurfer2
....Then you're not playing the current efficiently!!!!


Your sails worked pretty fast, even on their side. At least at Hiram's they did...


Jay

Re: fastest point of sail [Re: waterbug_wpb] #191501
09/21/09 04:08 PM
09/21/09 04:08 PM
Joined: Mar 2005
Posts: 160
claus Offline
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I would guess that this polar does not include the kite?

Re: fastest point of sail [Re: waterbug_wpb] #191505
09/21/09 04:16 PM
09/21/09 04:16 PM

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andrewscott
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andrewscott
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Originally Posted by waterbug_wpb
Your sails worked pretty fast, even on their side. At least at Hiram's they did...


Is that flying the tramp?

Last edited by andrewscott; 09/21/09 04:17 PM.
Re: fastest point of sail [Re: claus] #191518
09/21/09 07:21 PM
09/21/09 07:21 PM
Joined: Feb 2004
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scooby_simon Offline
Hull Flying, Snow Sliding....
scooby_simon  Offline
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Originally Posted by claus
I would guess that this polar does not include the kite?

Bet it does!

Roughly beam reaching is fastest. Putting the kite up for down wind means you can travel fast dpwn wind as this is where you want to go, but you also have a lot of drag up too!

The fastest point slowly goes more down wind as the wind increases as the Angle to apparent changes and the ability to use the power also changes!


F16 - GBR 553 - SOLD

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Re: fastest point of sail [Re: scooby_simon] #191542
09/22/09 01:05 AM
09/22/09 01:05 AM
Joined: Mar 2005
Posts: 160
claus Offline
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The curves at 7 and 10 knots indicate that going dead downwind is fastest with this tri for these wind velocities, which should not happen with a kite (45 sqm!). There is no typical kite lobe, the small max at 130 degrees for 20 knots would be compatible with a genova going downwind.

Re: fastest point of sail [Re: claus] #191662
09/22/09 01:43 PM
09/22/09 01:43 PM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
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I could maybe see that DDW might work in light windspeeds on that tri. I think the old Nacra 6.0 with "spin-zilla" did great VMG at DDW in under 10 kts.

This strategy didn't work so well with the high aspect spins of the early N20, however.


Jay

Re: fastest point of sail [Re: claus] #191674
09/22/09 02:49 PM
09/22/09 02:49 PM
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Posts: 3,528
Looking for a Job, I got credi...
scooby_simon Offline
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Originally Posted by claus
The curves at 7 and 10 knots indicate that going dead downwind is fastest with this tri for these wind velocities, which should not happen with a kite (45 sqm!). There is no typical kite lobe, the small max at 130 degrees for 20 knots would be compatible with a genova going downwind.


Looking at the curves; it looks like they do not go below 160!

Am I looking at the wrong polars?



F16 - GBR 553 - SOLD

I also talk sport here
Re: fastest point of sail [Re: scooby_simon] #191679
09/22/09 03:28 PM
09/22/09 03:28 PM
Joined: Mar 2005
Posts: 160
claus Offline
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Yes, they only go to 160, put the first derivative is practically zero in the case of 7 and 10 knots, so you expect a smooth behaviour towards 180. Even 160 is practically DDW for a cat/tri. Really thinking that this thing (300 kg and 45 sqm of kite) is only capable of going 5 knots downwind with 10 knots of wind??

Re: fastest point of sail [Re: claus] #191697
09/22/09 04:33 PM
09/22/09 04:33 PM
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Posts: 3,528
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scooby_simon Offline
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Originally Posted by claus
Yes, they only go to 160, put the first derivative is practically zero in the case of 7 and 10 knots, so you expect a smooth behaviour towards 180. Even 160 is practically DDW for a cat/tri. Really thinking that this thing (300 kg and 45 sqm of kite) is only capable of going 5 knots downwind with 10 knots of wind??


With an Asym kite; YES.


F16 - GBR 553 - SOLD

I also talk sport here
Re: fastest point of sail [Re: scooby_simon] #191702
09/22/09 05:16 PM
09/22/09 05:16 PM
Joined: Mar 2005
Posts: 160
claus Offline
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According to Bethwaite, this is about a Soling´s vmg speed downwind at 10 knots of wind (see page 333). I'd rather sail on the tri in a race wink


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