Bieker B6

[Amati]

When Hollom talks about Viscous forces dominating gravitational forces, you don't suppose that he means that the fin's low pressure reaches up around the hull to the gravity interface? I just spent an hour looking for a hydrodynamics paper on that very thing and of course I can't find it.

Paul,

I'm sure I've read a similar article somwhere in the distant past. I think it was to do with why elliptical keels should be narrower at the root with max chord lower down the keel. As Andrew says, I can understand this with keels that are exposed to the free surface due to heeling, but not with a wide hull sailed flat.

Of course at high speeds the i14 is planing and the centreboard may well be exposed more to the free surface. But with the planing hull half out of the water it will be even less effective at providing lateral resistance, so the argument still doesn't stand up.

Mal.

Ooh - I remember that paper - damn if I can't remember the title. I vaguely remember it being around circa 1995...

But it was more than just the exposure to the free surface as I recollect. It also had to do with reducing spanwise migration of surface induced aerated water if I recollect...

Yup yup that's the one...

My point (yes, I believe I had one :lol: ) is that too much aoa over a certain Reynolds Number regime (or maybe even speed?) excacerbated the effect the article above deals with, which might be why under 12K works for a gyber, but over 12 induces it (maybe ventilation of some sort?)? How much leeway resistance to you need off the wind anyway?

Just my imagination, or is the chine crowd happier with gybers than the non chines folk? If you think about it, if that's true, then I had it backwards ( ), and the more the hull resists leeway, the more a gyber is an advantage. So D.H. may have a point. (I love his stuff, but sometimes he riffs like Mr. Greenspan used to.)

Mr. Maas- you have chines, no?

Kind of makes me wonder about no chine hulls and gybers under 12K. Are Int 14 chines above the water enough over 12K so the hull essentially lifts up enough and becomes essentially a roundish no chine hull on plane, and then develop more leeway so the gyber becomes aoa overkill?

It seems to my eye that Paul usually puts his chines on the high side (?)- care to comment, Irrational 14er?

Paul

 

[Liquid]

How long is your board?

I sailed on one of the first B5 for the NZ worlds a few years back, it had a gyber and a long dagger board. We were higher than most (all?), in anything less than 12 kts ... Dunno if it was the long board or the gyber. Like Archie says, could be that you just need a longer fin.

Oh, my 14 needs a new board for sure. The current one is old and low aspect but very nice for standing on while righting the boat! The 'new' boards are a little wider than a balance beam!

 

[Liquid]

Paul Bieker has just completed the drawings for a plug and play system for the B6 which should be retrofittable to any boat with the most recent Russell Brown built board and able to accommodate a 3" centerboard trunk insert. This will take the fiddling out of the equation for those who have shyed away from their installation and use because of complexity. Stand by for details.

Sounds interesting...

 

[BalticBandit]

When Hollom talks about Viscous forces dominating gravitational forces, you don't suppose that he means that the fin's low pressure reaches up around the hull to the gravity interface? I just spent an hour looking for a hydrodynamics paper on that very thing and of course I can't find it.

Paul,

I'm sure I've read a similar article somwhere in the distant past. I think it was to do with why elliptical keels should be narrower at the root with max chord lower down the keel. As Andrew says, I can understand this with keels that are exposed to the free surface due to heeling, but not with a wide hull sailed flat.

Of course at high speeds the i14 is planing and the centreboard may well be exposed more to the free surface. But with the planing hull half out of the water it will be even less effective at providing lateral resistance, so the argument still doesn't stand up.

Mal.

Ooh - I remember that paper - damn if I can't remember the title. I vaguely remember it being around circa 1995...

But it was more than just the exposure to the free surface as I recollect. It also had to do with reducing spanwise migration of surface induced aerated water if I recollect...

Yup yup that's the one...

My point (yes, I believe I had one :lol: ) is that too much aoa over a certain Reynolds Number regime (or maybe even speed?) excacerbated the effect the article above deals with, which might be why under 12K works for a gyber, but over 12 doesn't induce it? How much leeway resistance to you need off the wind anyway?

Just my imagination, or is the chine crowd happier with gybers than the non chines folk? If you think about it, if that's true, then I had it backwards ( ), and the more the hull resists leeway, the more a gyber is an advantage. So D.H. may have a point. (I love his stuff, but sometimes he riffs like Mr. Greenspan used to.)

Mr. Maas- you have chines, no?

Kind of makes me wonder about no chine hulls and gybers under 12K. Are Int 14 chines above the water enough over 12K so the hull essentially lifts up enough and becomes essentially a roundish no chine hull on plane, and then develop more leeway so the gyber becomes aoa overkill?

It seems to my eye that Paul usually puts his chines on the high side (?)- care to comment, Irrational 14er?

Paul

Well 5ohs are chineless (chinless ) and they have more inconsistency with gyber performance...

But I suspect that "over 12" what's going on is that boat speeds are high enough that the AoA on the board has dropped enough that you might even be dragging the hull to weather (if IC Nutter's analysis is right)...

All I really know is what I've seen on the water, and If I were buying/building a boat, I'd go for a gyber. In fact when I was looking seriously at building a Swift Solo (I still might for the beauty of it) I was going to build it as a Gyber since they have no rules about it and use a "daggerboard box gasket" structure already.

 

[Presuming Ed]

Photos of plug and boat shamelessly nicked from:

http://forum.interna...t=1334&start=30

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[Andrew P]

[

/monthly_02_2011/post-419-027477100%201298617545_thumb.jpg

Depth of the main bulkhead and the longitudinal web appears to be bigger than the B5. This will probably require the deck to be higher/closer to the sheer line. In turn this might make the boat a bit more difficult to sail in bigger waves through tack and gybes.

Interesting that the structure doesn't require an X frame under the mast with this design.

 

[joe.bersch]

When you see the mast step/deck configuration, you will see why. Hopefully, we will be able to post photos of that before the weekend's over. The deck is only slightly higher aft than the 5, I believe. This should make the boat a little easier to tack with a little extra flotation in the stern.

FJB

 

[Liquid]

Tick tock... Splashing in 30 days for the SD NOOD!

 

[joe.bersch]

No- more like 23 and counting down quickly.

 

[BalticBandit]

Photos of plug and boat shamelessly nicked from:

http://forum.interna...t=1334&start=30

/monthly_02_2011/post-419-092395300%201298617588_thumb.jpg

/monthly_02_2011/post-419-096549700%201298617640_thumb.jpg

/monthly_02_2011/post-419-027477100%201298617545_thumb.jpg

DAMN that's a sexy beast.

 

[Pete M]

I like the way Paul has recognized how the current 14s are sailed, and instead of designig a fast planing boat, or a good light air boat, or an all 'round boat - Paul has designed a two mode boat - Mode one is light air with the bow down, and mode two is bow up and planing - no middle ground - it's either / or

 

[BWR]

No- more like 23 and counting down quickly.

Pressure is on! The boat is registered for San Diego NOOD. Do we really have to crack a Stone IPA across it's bow to christen it? Anyone who's around, come down to Fiddler's on NOOD weekend to check out the new boat!

There ya go Kris, Kim, and Joe - does that put enough pressure on the complete the boat?

 

[Pete M]

No IPAs - too hoppy

 

[joe.bersch]

The pressure is on indeed, Brad. Pete, if you don't like Stone IPA, then bring your own beer!! Bring a drill, screwdriver and some caulking too. We may be rigging by flashlight! We popped the deck tonight- 24#. Mast step bonds tomorrow. It is gonna be tight, but it is coming along.

Joe

 

[joe.bersch]

Andrew P- there is a photo posted on the i14 page of the mast step installation. Yeah, I know. Sorry it is out of focus, but it shows you the details of the install. Got the centerboard cassette box installed yesterday and glued the deck on. I will take some photos of the guts of the jibing assemble and post them by week's end, I hope.

FJB

 

[BWR]

MORE PHOTOS!! UPDATE!!

 

[Pete M]

one week to go

 

[joe.bersch]

Come on Pete, it is two weeks if you don't count the driving! We are gonna be there one way or another. Are you planning to come? Heard Ron might not be able to make it.

The boat came out of the mold yesterday. 89# with the hull and deck. Incredibly fair straight out of the mold. Feels really strong, just like my pre preg boat. I really like her lines. I finished the cradle tonight so we are ready to travel. Kris finished the last two rack struts. I expect they might be installed tomorrow with racks attached as well. Kris is also finishing the rudder gantry. I suppose she will be painted by late next week, leaving a day or two for rigging. Jay Glaser is ready to make the sails as soon as we put the rig in the boat and give him some numbers. New rudder coming from Larry Tuttle.

Sorry, I can't seem to load the photos from yesterday to this site, maybe someone can shamelessly nick them from the I14usa.org site and post them under the proper file extension here.

Joe

http://forum.international14.org/do...be78856f73f28030bcf7128f0697647&mode=view[/URL]

 

[Presuming Ed]

Shamelessly nicked.

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[14er]

FJB,

Does this mean I need to get all of my crap out of our trailer??

You (and Hendo, Bieker and Kim) are a man of action!

KJB