Btw Wouter, I though your anwser was concise and well worded.

Thank you Bill.


correction :

Quote of "60 degrees" should be replaced by "over 30 degrees", basically 30 to 45 degrees depending on some details.

I had to do some quite calculations and took the wrong angle when writing my initial posting. Any wing will stall at 60 degrees angle of attack (even delta wings), so I should have spotted that immediately.

Sorry,

Wouter

I agree, Wouter - nicely well worded reply.

Bill - one minor point:


The flaps increase the camber, not the angle of attack. More camber creates more lift at higher angles of attack (without stalling), but at the expense of greater drag. The extended flaps (and leading edge slats) also introduce a slot that helps the airflow remain attached (not stall), as does the slot on the sailing wing.

OK, now that we have that sorted out, let's start talking about Vortex Generators... <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

And Bill, all top level competition aerobatic aircraft use completely symetrical wings now, they fly just as well upside down as right-side up, same as Ben's Wing has to be symetrical for use on each tack. The difference is Ben has a slotted flap that he uses to change the camber to asymetric, on each tack. The competition acro planes do not use flaps. (Google up a good picture of a Sukoi 31 wing)

Matt,
I wasnt going to introduce the concept of camber, but you are right, wing on planes dont rotate.

And Timbo, thats interesting, I didn't know that.

I've always been able to relate whats going on with a modern wing mast with whats happening on a passenger jet. Probably because I spend so much time on passenger planes.

Well, passenger jets only have to fly right side up, but the competition acro stuff has to do both, changing the angle of attack gives one side of the wing more lift, thus they can fly with a 100% symetrical airfoil. If you put a big enough engine on it, you can make a barn door fly, but they had to put two of them on the F4! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Inside joke for any of you sled drivers out there.

Our soft sails are akin to the Wright Bro's. early cloth covered wings. Wing development has come a long way in the past 100+ years, but we are still using soft wing technology. It does add to ease of use (you can roll them up and put them in a sock) and keep our costs down.

Who wants to be a "Wing Sherpa" at a regatta and buy a huge box to carry it in? Not too many, so I predict the Wing, while being obviously better ie. generating more lift, will not catch on in large numbers. Too cumbersome to transport, might be too fragile if you land on it in a capsize... and too expensive to replace if (excuxe me, I meant WHEN) you break it. <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />

Can the wing rigged cat be righted solo after a capsize? Has this been tried, or tested? Furthermore, if one should pitchpole in big air, how likely is the mast to stay in one piece?

maybe this

WOW
That's really flying a hull to the limit. <img src="http://www.catsailor.com/forums/images/graemlins/ooo.gif" alt="" />
And check the guy doing a hand stand on the upper hull.
Those kids and their wacky toys!

Man, that looks fast, what with the reduced drag by keeping only one hull in the water and the lift from the sideways wing...and check out that trapeeze style, upside down and backwards! <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

thanks for all those pics lesburn1, very interesting to see close ups of things people are talking about here, like those narrow daggers, rudders and of course the wing

in the oops pics you have what looks to be the wreckage of a homebuilt? ply cat called "kiwi magic"

what happened to it, stress failure, collision?

long way to bring a boat from new zealand to have that happen to it

eric e

http://share.shutterfly.com/action/...p;amp;emid=sharshar&linkid=link4

lots of pics from the Hop.

According to the online book "See How It Flies" from John Denker, flaps increase the camber and the angle of attack.

He uses the definition of angle of attack as being the angle of the wing relative to a position where it would provide zero lift. Your definition might be different.