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BaldieJr
02-20-2007, 11:39 AM
Suppose I have a wing with the same shape on either side. Will it fly without a flap if the angle of attack is changed?

I ask because I know nothing about this sort of thing but would love to try a rigid wing for sailing.

BaldieJr
02-20-2007, 11:39 AM
Suppose I have a wing with the same shape on either side. Will it fly without a flap if the angle of attack is changed?

I ask because I know nothing about this sort of thing but would love to try a rigid wing for sailing.

LStarosta
02-20-2007, 11:45 AM
Most acrobatic planes tend to have symmetric airfoils which allow them to fly just as well inverted as they do normally.

Extra300 is an example. And it has no flaps.

p-11.cAce
02-20-2007, 12:25 PM
wingsails.com (http://www.wingsails.com/cetiri.html)
Might have to build one for my Hobie http://forums.ubi.com/images/smilies/25.gif

BaldieJr
02-20-2007, 12:27 PM
In that case, I don't understand why so many experimenters are playing with camber adjustments.

I recently saw an ice-boat that had a wooden wing instead of sails. It used a flap to set the camber. Presumably because the wing did no turn on its axis. Seems kinda dumb to me but hey its an ice-boat.

Bremspropeller
02-20-2007, 01:20 PM
I found a black hole on my butt yesterday.

p-11.cAce
02-20-2007, 01:40 PM
I think there may be two issues here:
CAMBER adjustment would be made with a flap.
AoA adjustment is made with the elevator (in the Extra) or the rudder (in a boat).
If you have a wing without a flap its camber is fixed, leaving only a small range of AoA within which its lift is maximized. If you have a flap, you can now alter the camber AND AoA to maximize lift available in relation to varying airspeeds. The lower cambered foil generates less induced drag but is optimized for higher speeds and will stall at a relatively low AoA. The higher the camber the greater the induced drag becomes as speeds increase, but the stall does not occur until much greater AoA.