finally formula sailing with wave masts

if you are talking speed sailing off the wind then high aspect is still faster as i understand it.

but upwind lower aspect has the edge and in my mind always has. i myself prefer lower aspect sails because i like to sail upwind and enjoy the improved acceleration they provide, i was never really a convert to the whole high aspect thing. but then i'm not a speed sailor.

there has been some interesting discussions on the KA forums about the comparison between the KA Koncept and the KA Race which makes good reading. to take one comment out of the discussion the KA Race (lower aspect) performed better upwind.

edit* the thing i find amazing about that north sail is the size of the head!!! how much drag must it create?

A good sailor will be fast, no matter what equipment his sponsor makes him use

Chris Lockwood was on to this years ago but had trouble getting it put into practice for a couple of reasons. Severne built him a couple of Low AR sails but they didn't work out for a number of reasons and it wasn't helped by the canal at St Marie del la Mer in France having a metre high windward bank which suited Finian's high AR Naish sails and left Chris in disturbed air with his low AR Severnes. Additionally Dan Engdahl was also on Severnes pushing for the oppposite in his protos on the basis of better aerodynamic efficiency.

Of course all aerodynamic theory is based on planes which have another wing on the othe side of the fuselage to balance the lift forces. Maybe if the passengers had to hold the wings on we would be flying around in planes with low AR wings

The new Pryde protos have much shorter luffs. I think Chris had a 400 in his 6.2 when he did 45Kn at Pt Walter. The North is a bit different as it has a huge head..it looks like they just chopped the top pannel off.

As Bugs is about to design me 3 new sails, I forwarded this post on to him for his comments.
Here they are

That is the correct way to go, and is in line with the way I have drawn up the new sails for the ( not too distant ) future.
The correct comment should be "look how small and inaffective the heads are on those other rigs!"

There would be far more profile drag created by the extra mast length which is supporting unused sail surface (even more drag ) than having a shorter mast with a broarder head (which whould, if set up correctly, be createing more power and being useful,not just being towed around all day)

The aim should always be to make sure that there are no unnessasary bits hanging around, more efficient design is all about that.

As for high or low aspect, low aspect is naturally less twitchy and so is easier to trim upwind and generally set flatter also.
Higher aspect sails will naturally be set deeper and will be happier running further downwind

I'm not sure about formula booms but I suspect it would be hard to get the same depth to chord ratio on the low aspect sails as the high. So as Bugs says they would be set flatter, contributing to the upwind/downwind difference.
But I'm talking about sails under 6.0m they'll still be able to rig with as much draft as needed to go downwind fast.

sailquik said...

Gestalt said...

if you are talking speed sailing off the wind then high aspect is still faster as i understand it.

I not so sure about that Gestalt. You have to have the power down low where you can use it. If anything, I might be the opposite in theory as lift to drag ratio is most important upwind.
Speed sailors typically twist and flatten the top of sails to lower the C of E. So why even have all that draggy cloth up the top?
I think testing and development has shown that theoretical high aspect ratio advantages are of little or no consequence in practical windsurfing.

i'll definately take your word on that sailqik, experience reins supreme.