Whats the drag when canted 20 degrees?

On the 60' at 2' wide I see an almost symetrical under water plane with a very fare shape at 20 degrees of heel. With about 156sqft of wetted surface area at a 12''draft.

Todd

--- In harryproa@yahoogroups.com.au, Dennis Cox <dec720@...> wrote:
>
> Todd,
>
> Still fascinated with the flat hull preheeling or canted hulls. In the right
> condition I swear I can see the leehull on CatPrao generating lift.
>
>
> I sure hope so... seeing that 10% more drag than a rounded hull says it'll be a
> relative dog in light wind.  At least compared to the big cats I'll run
> against.  If it gets any planing... its a whole new ball game! 
>
>
> Dennis
>
>  
>
>
>
> ________________________________
> From: tsstproa <bitme1234@...>
> To: harryproa@yahoogroups.com.au
> Sent: Wed, August 25, 2010 1:55:24 AM
> Subject: [harryproa] Re: Wings Sails
>
>  
> Don't know, Largest boats built 16'ter's built from models. Did exactly what the
> model did. Scaling is another intricate number game. I use 1/12 scale I would
> first find where you want the 4.5 tons to sit and design accordingly with what
> beam and with what kind of rocker and how much free board. The model would then
> be weighted to sit on the scale waterline/draft. Then sailed with no extra
> weight added. I know you can't scale everything but keeping it in perspective
> should get you close. Keeping an eye on your models weight, water line, and sail
> size helps too. If the models weight is too heavey and sitting above waterline
> mark its no good needing more weight more sail area everything gets thrown out
> of perspective. I use balsa wood and CA glue and kyrlon spray paint to seal the
> wood. The thickest balsa I use is 3/32 on the larger models 1/16 -1/8 on the
> smaller models. Models are extremely light fragile and don't stand up to alot of
> out of water abuse.
>
>
> I was going to do a 48'/inch hull. But I'll do a 60'' and attach one of my 36''
> hulls to it. I'm thinking 12-14''draft on a 18'' beam with a 48'' sheer height.
> That gets me around 2 ton. Could change as I see it come together.
>
>
> Still fascinated with the flat hull preheeling or canted hulls. In the right
> condition I swear I can see the leehull on CatPrao generating lift.
>
>
> Todd
>
> --- In harryproa@yahoogroups.com.au, Dennis Cox <dec720@> wrote:
> >
> > Todd,
> >
> > From your experience, have you had any issues scaling to your full size test
> > rig?  How about to far larger... 60', 4.5 tons?
> >
> > Dennis
> >
> >
> >
> >
> > ________________________________
> > From: tsstproa <bitme1234@>
> > To: harryproa@yahoogroups.com.au
> > Sent: Tue, August 24, 2010 12:46:30 AM
> > Subject: [harryproa] Re: Wings Sails
> >
> >  
> > I'll go with my instinct and testing. Somethings amiss here. Look at some of
> >the
> >
> > top high end hand launch gliders. Their wings are thin and cambered in a way
> > very similar to my single skin except for their dedicated leading and trailing
>
> > edges. Granted theses are thermal gliders hand launched like a boom-rang not
> > winch assisted heavy fast flying thermal soarers. Theramal soarers can achieve
>
> > speeds over 60mph where as hand launch thermal gliders very rarely see 30mph.
> > The l/d ratio's have to fit the speed in which the craft is meant for and the
> > purpose of the craft and I'd assume the weight of the craft as well.
> >
> >
> > Not a number guy , I go by past experiences, on instinct, and by what I see
> > working.
> >
> >
> > I could get the double skin to work better but to me the outcome wouldn't be
> > worth it. Its sail seems sluggish none respnsive or slow to respond . Driving a
> >
> > car with a lose steering wheel. The single skin bamb... 911 porche. super
> > responsive goes where you point it when you point it and tells you when you
> >have
> >
> > gone to far quickly all ways in touch.
> >
> > I have done other double skin wings and its starting to bring back memories of
>
> > why I didn't proceed.
> > http://www.youtube.com/watch?v=YDzG98DPvto
> > http://www.youtube.com/watch?v=YDzG98DPvto
> > http://www.youtube.com/watch?v=_PaWgwc4HwI&feature=related
> >
> > But I always keep coming back to this.
> >
> > http://www.youtube.com/watch?v=CCSoZOwQY6g
> >
> > Cause is it just works so damn well.
> >
> > Todd
> >
> >
> > --- In harryproa@yahoogroups.com.au, Rick Willoughby <rickwill@> wrote:
> > >
> > > Todd
> > > The thin section will perform slightly better than a fat section.
> > > The fat section is more forgiving. You need less sail area and the
> > > maximum lift will be more than the maximum drag.
> > >
> > > The fat section shape should be close to flat one side with nice
> > > rounding on the nose - something like attached mirrored.
> > >
> > > It should be a bit more than half the area you have now.
> > >
> > > The higher lift of the fat section is negated somewhat by the higher
> > > induced drag. You can reduce this negative to some degree by fencing
> > > the bottom. In fact any of the fixed wings should be improved by
> > > fencing the bottom either by having them operate close to a deck or
> > > fit a plate on the bottom of the sail. You could then carry the full
> > > chord all the way to the bottom.
> > >
> > > I could not get to the photo on the link you posted.
> > >
> > > Rick
> > > 
> > > On 23/08/2010, at 3:58 AM, tsstproa wrote:
> > >
> > > > No, you can not just let go and expect it to depower you have to
> > > > put the sail to the correct position to depower via controls. I
> > > > think of it as more of a mental block or learning curve in sailing
> > > > with this type of sail.
> > > >
> > > > The sail I have now is 2% thickness with a 9.6% camber. Or 1/4''
> > > > thick x 13 wide x 1.25 deep at center chord. The camber is pretty
> > > > consistent staying at about 9.6 though the bottom 3/4 of sail
> > > > coinciding with its chord the top 1/4 or so becomes alittle less.
> > > >
> > > > To me If I went with a 2.6'' wing thickness it kinda defeats the
> > > > whole purpose of going fast. Sure people will argue higher lift to
> > > > drag coefficient reduces drag is more efficient has a greater range
> > > > but look at that section of air it has to cut out. Vs 2% thickness
> > > > that has a camber of 10% its not a flat plate. Would it really sail
> > > > faster have better control have better range?
> > > >
> > > > Maybe your confusing wing thickness with camber?
> > > >
> > > > Here's a clip of a few more thorugh the water hull shots loading
> > > > the leeward hull while sailing into the wind to see what happens.
> > > >
> > > > http://www.youtube.com/watch?v=LrezrEfQj68
> > > >
> > > > Did a 180 sq inch 23''span ,10 '' chord, 2'' thick. Just to test
> > > > double skin vs
> > > > single skin Asymmetrical section.
> > > > Pics here
> > > > http://groups.yahoo.com/group/Wind_Powered_Shunting_Craft/photos/
> > > > album/2009757739/pic/list
> > > >
> > > > Here's first test 180 sq'' bi-directional asymmetric sail.
> > > > http://www.youtube.com/watch?v=uRYTVcfmns8
> > > >
> > > > The double skin asymmetric sail creates very little drive vs the
> > > > single skin cambered. Its heavier has less range and to me seems
> > > > piss poor in performance. Unless in higher winds . I can see where
> > > > a double skin could be improved upon to make work ,being a
> > > > combination of single skin camber and double skin thickness. But
> > > > were is the innovation in that all you have to do is look at the
> > > > oracle wing sail sail. I'll stick with my true asymmetrical single
> > > > skin Bi- directional for now.
> > > >
> > > > Todd
> > > >
> > > > --- In harryproa@yahoogroups.com.au, Rick Willoughby <rickwill@>
> > > > wrote:
> > > > >
> > > > > Todd
> > > > > By feathering I am referring to a full size version where you
> > > > want to
> > > > > release sail force by releasing the sheet or whatever is controlling
> > > > > the sail AoA. The symmetrical sail does not feather when released or
> > > > > only over a very narrow range. An interesting test would be to
> > > > > release your control rods to the mast and see where the sail
> > > > rotates.
> > > > >
> > > > > The middle mounted rudders do provide a load release mechanism that
> > > > > allows leeway when clear of the water. I can see the benefit in
> > > > that.
> > > > >
> > > > > At speeds above a few knots on a full size craft ventilation will be
> > > > > performance limiting. Hence I see merit in under the hull rudders.
> > > > > They could be under the windward hull if you want some force release
> > > > > mechanism. The instant that they ventilate will cause the boat to
> > > > > round up a little so some inbuilt protection. If the front one goes
> > > > > first then there will be an instant of lee helm before the aft one
> > > > > lets go.
> > > > >
> > > > > Your cambered thin wing will have a working range of a few degrees
> > > > > when on the wind. The lift drops to under half about 5 degrees
> > > > > either side of maximum lift. The 10% series 07 foil will work over
> > > > > twice that range and if you went up to a 20% thick section it would
> > > > > have twice the lift and work over 25 degree range - so more
> > > > > progressive. Having double the lift coefficient allows you to halve
> > > > > the sail area. This means the maximum drag when the sail is
> > > > > perpendicular to the wind is halved so risk of capsize is reduced.
> > > > > You can provide this same protection by putting more curve into your
> > > > > thin sail and reducing the area but it will still only have a narrow
> > > > > range of operation.
> > > > >
> > > > > Rick
> > > > > On 19/08/2010, at 2:58 PM, tsstproa wrote:
> > > > >
> > > > > > Thanks Rick
> > > > > >
> > > > > > What do you mean by feathering?
> > > > > >
> > > > > > More range in what way pointing ability or same sail size for
> > > > > > higher wind strengths or both ?
> > > > > >
> > > > > > I'm sailing right in front of a shallow shelf so tring to keep
> > > > boat
> > > > > > close for through water hull shots. At 5:00 in Last part of video
> > > > > > thinking of a way to show leeway if any. I'm not moving the
> > > > > > steering boards just manipulating the sail only. Boat pretty much
> > > > > > stays in same position as it see-saws back and forth actually
> > > > gains
> > > > > > ground in the puffs.
> > > > > >
> > > > > > Also starting at 2:35 on the clip look as it heels and slides
> > > > > > sideways don't no if thats a good thing or not, but better than
> > > > > > digging and catching an edge. An argument for center hung
> > > > boards vs
> > > > > > leeward hung boards might correct of hinder the situation. I know
> > > > > > the canted of hull helped the slide.
> > > > > >
> > > > > > No, I'm using symmetrical.
> > > > > >
> > > > > > When I put the camera down the performance goes up two hands vs
> > > > > > one. Towards the end of the day I was tring everything to get
> > > > it to
> > > > > > ride on leeward hull alone in the 4.5 mph wind it wouldn't thats a
> > > > > > good thing to me. I'm hoping in about 6 to 8 range it will still
> > > > > > stay somewhat planted. In more wind canting the rig to windward or
> > > > > > reducing sail size.
> > > > > >
> > > > > > Todd
> > > > > >
> > > > > > --- In harryproa@yahoogroups.com.au, Rick Willoughby <rickwill@>
> > > > > > wrote:
> > > > > > >
> > > > > > > Todd
> > > > > > > Very nice work.
> > > > > > >
> > > > > > > It is so simple with the rigid bi-directional wing. The only
> > > > problem
> > > > > > > is lack of feathering but that could be overcome.
> > > > > > >
> > > > > > > A thick sail section like I did for the rudder would have wider
> > > > > > range
> > > > > > > of control. It might be a bit more progressive on the controls
> > > > > > >
> > > > > > > Are you using asymmetrical rudders?
> > > > > > >
> > > > > > > Rick
> > > > > > > On 19/08/2010, at 11:05 AM, tsstproa wrote:
> > > > > > >
> > > > > > > > CatPrao ProaCat AURORA 36'' x 1/2'' x 3'' with 12'' rocker.
> > > > hulls
> > > > > > > > are canted 20degrees outward.
> > > > > > > >
> > > > > > > > http://www.youtube.com/watch?v=FCEvPdnhShk
> > > > > > > >
> > > > > > > > Todd
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > > Rick Willoughby
> > > > > > > rickwill@
> > > > > > > 03 9796 2415
> > > > > > > 0419 104 821
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > > Rick Willoughby
> > > > > rickwill@
> > > > > 03 9796 2415
> > > > > 0419 104 821
> > > > >
> > > >
> > > >
> > >
> > > Rick Willoughby
> > > rickwill@
> > > 03 9796 2415
> > > 0419 104 821
> > >
> >
>