sail aerodynamics

Maybe +- 0.5 degrees for twist, +-0.5% for camber, +- 0.5 degrees for the leech exit angle. Twist is the most important.

Yes, for 25 years or so, both flying shapes & the data to CFD. See here for an example from the early 90's.. We still use cameras (video) to pick up the sail shape.

How would you use a microphone?

 

The microphone picks up turbulence of the boundary layer and clears up outside the boundary layer. A microphone is a dynamic pressure sensor.

 

Thanks Mikko,

To me the flap seems to have been an outright success, it tested superior at all angles and scored a win on the track. This even as it does not seem from the picture that you tried to keep its height-to-cord constant over the height of the sail by tapering it off towards the masthead just like the sail itself. I guess this is behind most of the underperformance versus your 2-D test. And I guess also that you had to keep its height down due to concern over class rules. What I gather from literature, the flap-height optimally occupies most of the boundary layer but it should not reach the free-stream. Hence you should not expect a small flap to be efficient in slow winds as you then are dealing with thick boundary layers, but if you were able to sport a larger flap it might get a good addition to much needed lift in that case.

Doesn't your wind tunnel and race track experience point to good use for flaps, especially for cruising when not constrained by rules?

 

I understand this thread is ancient...But, here is what I did, I favor old cotton sails and never saw need for battens with some rigs, so I punted....the boat shown here has hook/loop fasteners to spars, no battens with slight added luff and leach...in short, I punted and rig moves as it should...to me...is fast and uncomplicated, Simple, to me, is best...if it looks good, tis good...and it worked, for me.

 

So we're going to see some breakthrough sailmaking from Scandinavia? How awesome is that!
Polstar is the new Saab (no matter what they say)!

 

Stephen,
Me a aimple swab just give me soft yes, Dacron ain't cotton, but always had a hen for collapleabe winger...but suckers are complex, so we gave up designs and hope...

 

Practical is pragmatic!
Wings are tall, fast and expensive and impractical,,,to me.