Re: [bolger] AS29 - vortex generators ?
It seems as if vortex generators act in a similar fashion to the meginhufr
of Viking ships. Meginhufr (or meginhufer) means strong plank and is a
horizontal plank that forms an upside-down L shape in the hull that will
spin off a strong vortex. There's a drawing here:
http://www.megin.dk/Erland1.htm.When the boat is looked at from behind, one
can see two vortexes trailing behind making the boat look as if it's riding
on two rails. These vortexes reduce wave-making resistance and reduce
leeway.
Fred Schumacher
of Viking ships. Meginhufr (or meginhufer) means strong plank and is a
horizontal plank that forms an upside-down L shape in the hull that will
spin off a strong vortex. There's a drawing here:
http://www.megin.dk/Erland1.htm.When the boat is looked at from behind, one
can see two vortexes trailing behind making the boat look as if it's riding
on two rails. These vortexes reduce wave-making resistance and reduce
leeway.
Fred Schumacher
On Tue, Apr 21, 2009 at 8:42 PM, Bill Kreamer <kreamers@...>wrote:
>
> My understanding is that vortex generators create small areas of
> turbulence(and small amounts of drag) that, by energizing the local flow,
> enable theflow to remain attached to a lifting surface a bit longer as its
> angle ofattack increases, instead of separating earlier and creating lots of
> drag.
>
[Non-text portions of this message have been removed]
My understanding is that vortex generators create small areas of turbulence
(and small amounts of drag) that, by energizing the local flow, enable the
flow to remain attached to a lifting surface a bit longer as its angle of
attack increases, instead of separating earlier and creating lots of drag.
I don't see vortex generators entirely replacing the lifting function of a
board. Anyway, don't be afraid of boards - they provide adjustability,
letting one boat do things it couldn't do otherwise. Some are quite robust
and trouble-free. I like boards in cases, like centerboards or bilgeboards,
even though cases require maintenance. As far as the drawbacks go, it's all
in the designer's wrist, so to speak.
- Bill K.
_____
From:bolger@yahoogroups.com[mailto:bolger@yahoogroups.com] On Behalf Of
jcjglt
Sent: 2009-04-20 11:59
To:bolger@yahoogroups.com
Subject: [bolger] AS29 - vortex generators ?
In June of 2007 a member of this group, Nels, wrote " the hull (of the AS29)
is almost a carbon copy of a larger liveaboard version of Paradox".
What do members think of vortex generators to replace the bilgeboards ?
Your comments are of interest as I am considering the building of this
amazing sailboat but not so much by bilgeboards or any other kind of boards
(dagger- or leeboards).
Best regards to all,
jcjglt
[Non-text portions of this message have been removed]
(and small amounts of drag) that, by energizing the local flow, enable the
flow to remain attached to a lifting surface a bit longer as its angle of
attack increases, instead of separating earlier and creating lots of drag.
I don't see vortex generators entirely replacing the lifting function of a
board. Anyway, don't be afraid of boards - they provide adjustability,
letting one boat do things it couldn't do otherwise. Some are quite robust
and trouble-free. I like boards in cases, like centerboards or bilgeboards,
even though cases require maintenance. As far as the drawbacks go, it's all
in the designer's wrist, so to speak.
- Bill K.
_____
From:bolger@yahoogroups.com[mailto:bolger@yahoogroups.com] On Behalf Of
jcjglt
Sent: 2009-04-20 11:59
To:bolger@yahoogroups.com
Subject: [bolger] AS29 - vortex generators ?
In June of 2007 a member of this group, Nels, wrote " the hull (of the AS29)
is almost a carbon copy of a larger liveaboard version of Paradox".
What do members think of vortex generators to replace the bilgeboards ?
Your comments are of interest as I am considering the building of this
amazing sailboat but not so much by bilgeboards or any other kind of boards
(dagger- or leeboards).
Best regards to all,
jcjglt
[Non-text portions of this message have been removed]
Build as designed. Try on some chine extensions then, at reduced risk.
Graeme
Graeme
--- Inbolger@yahoogroups.com, "jcjglt" <jcjglt@...> wrote:
>
> In June of 2007 a member of this group, Nels, wrote " the hull (of the AS29) is almost a carbon copy of a larger liveaboard version of Paradox".
> What do members think of vortex generators to replace the bilgeboards ?
> Your comments are of interest as I am considering the building of this amazing sailboat but not so much by bilgeboards or any other kind of boards (dagger- or leeboards).
> Best regards to all,
> jcjglt
>
In June of 2007 a member of this group, Nels, wrote " the hull (of the AS29) is almost a carbon copy of a larger liveaboard version of Paradox".
What do members think of vortex generators to replace the bilgeboards ?
Your comments are of interest as I am considering the building of this amazing sailboat but not so much by bilgeboards or any other kind of boards (dagger- or leeboards).
Best regards to all,
jcjglt
What do members think of vortex generators to replace the bilgeboards ?
Your comments are of interest as I am considering the building of this amazing sailboat but not so much by bilgeboards or any other kind of boards (dagger- or leeboards).
Best regards to all,
jcjglt