nadt770 Posted January 31, 2006 Share Posted January 31, 2006 What is the reason for going to a canard with dihedral? I'm just curious. John Quote Link to comment Share on other sites More sharing options...
Jon Matcho Posted January 31, 2006 Share Posted January 31, 2006 The theory is that by doing this the ailerons will have more undisturbed air crossing them, which will increase the roll rate/authority. However, the theory is not yet a proof and most are keeping their canards straight. Quote Jon Matcho Builder & Canard Zone Admin Now: Rebuilding Quickie Tri-Q200 N479E Next: Resume building a Cozy Mark IV Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted February 1, 2006 Share Posted February 1, 2006 The theory is that by doing this the ailerons will have more undisturbed air crossing them, which will increase the roll rate/authority. However, the theory is not yet a proof and most are keeping their canards straight.That may have been the original theory, but the folks that have the dihedral canards say that they can't tell any difference whatsoever from the straight one. Mostly, it's for looks. Quote Marc J. ZeitlinBurnside Aerospacemarc_zeitlin@alum.mit.eduwww.cozybuilders.org copyright © 2023 Link to comment Share on other sites More sharing options...
Jon Matcho Posted February 1, 2006 Share Posted February 1, 2006 Mostly, it's for looks.But... what about those that don't think it looks better? I, for one, am not smitten with the look. Quote Jon Matcho Builder & Canard Zone Admin Now: Rebuilding Quickie Tri-Q200 N479E Next: Resume building a Cozy Mark IV Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted February 1, 2006 Share Posted February 1, 2006 But... what about those that don't think it looks better? I, for one, am not smitten with the look.I'm with you - I think it looks like crap, but that's what makes the world go round. Quote Marc J. ZeitlinBurnside Aerospacemarc_zeitlin@alum.mit.eduwww.cozybuilders.org copyright © 2023 Link to comment Share on other sites More sharing options...
Jack Morrison Posted February 1, 2006 Share Posted February 1, 2006 I agree with Jon and Mark. The wings are straight, why a dihedral canard, just does not follow any form as I see it. Jack Morrison E Racer 113 Quote Link to comment Share on other sites More sharing options...
nadt770 Posted February 1, 2006 Author Share Posted February 1, 2006 Thanks for the input guys. I also like the looks of a straight canard. Quote Link to comment Share on other sites More sharing options...
Wayne Hicks Posted February 1, 2006 Share Posted February 1, 2006 Vance Atkinson (Cozy III) is on record in the CSA newsletters as saying: 1. The dihedral canard is more complex to build. 2. Takes longer to build. 3. He saw NO performance gains from his previous straight canard. 4. Would never do it again, wasn't worth it. Quote Wayne Hicks Cozy IV Plans #678 http://www.ez.org/pages/waynehicks Link to comment Share on other sites More sharing options...
jperryfly Posted March 14, 2006 Share Posted March 14, 2006 I think Rutan's airfoil guru is the one that came up with it. I've got one so I'm one that is all for it. Quote Long Ez, AeroCanard Link to comment Share on other sites More sharing options...
Lifessamsara Posted April 13, 2006 Share Posted April 13, 2006 I had no idea that people had constructed AND flown with dihedral canards? Has anyone experimented with swept canards to anyones knowledge, and if so, the results/comments? Cheers, Bruce. Quote Link to comment Share on other sites More sharing options...
Richard Riley Posted April 14, 2006 Share Posted April 14, 2006 A swept canard would be significantly more complex to build. It could be done, and it might look snarky, but it wouldn't be faster. You'd have to do a different canard attach system, since it would put torque on the current lift tab system. Since the elevators would no longer be in line you'd have a more complex way of activating them. Since span would be reduced you'd be creating more induced drag for the same lift. Quote Link to comment Share on other sites More sharing options...
Lifessamsara Posted November 7, 2007 Share Posted November 7, 2007 Is there any substance in the theory that the dihedral Canard reduces the wash over the strakes/wings and therefore reduces drag? Bruce. Quote Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted November 7, 2007 Share Posted November 7, 2007 Is there any substance in the theory that the dihedral Canard reduces the wash over the strakes/wings and therefore reduces drag? Bruce. No performance difference has ever been measured on any aircraft that has changed from a straight to a dihedral canard. Quote Marc J. ZeitlinBurnside Aerospacemarc_zeitlin@alum.mit.eduwww.cozybuilders.org copyright © 2023 Link to comment Share on other sites More sharing options...
Lynn Erickson Posted November 7, 2007 Share Posted November 7, 2007 I had no idea that people had constructed AND flown with dihedral canards? Has anyone experimented with swept canards to anyones knowledge, and if so, the results/comments? Cheers, Bruce. yes, the beech starship and the zunni at chino have sweep canards. done to shift center of lift Quote Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years Link to comment Share on other sites More sharing options...
Richard Riley Posted November 7, 2007 Share Posted November 7, 2007 No performance difference has ever been measured on any aircraft that has changed from a straight to a dihedral canard. In theory, there's a clear advanatage for the dihedral canard. By raising the tips, the canard wingtip vortex passes over the strakes with more clearance. Now, in theory, there's no difference between theory and practice. In practice - Marc's correct. Any difference in performance is not measurable. Quote Link to comment Share on other sites More sharing options...
Lynn Erickson Posted November 7, 2007 Share Posted November 7, 2007 In theory, there's a clear advanatage for the dihedral canard. By raising the tips, the canard wingtip vortex passes over the strakes with more clearance. Now, in theory, there's no difference between theory and practice. In practice - Marc's correct. Any difference in performance is not measurable. there was a study on a long eze done by a collage student and that study deterined that the tips needed to be 14" higher to make a difference Quote Evolultion Eze RG -a two place side by side-200 Knots on 200 HP. A&P / pilot for over 30 years Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted November 7, 2007 Share Posted November 7, 2007 there was a study on a long eze done by a collage student and that study deterined that the tips needed to be 14" higher to make a differenceI think you're referring to these two "reports": http://users.wpi.edu/~stay1or/INTROW.html and: http://users.wpi.edu/~stay1or/canard2.htm We've discussed these a couple of times here, once a year and a half ago at: http://www.canardzone.com/forum/showpost.php?p=11252&postcount=74 and again a month ago at: http://www.canardzone.com/forum/showpost.php?p=16827&postcount=53 I wouldn't use any of the "conclusions" that were drawn in these papers (and I couldn't find any reference to a 14" canard height above the main wing in them, but I didn't kill myself looking) as an indication of what anyone should or shouldn't do regarding full scale aircraft (or even models, for that matter). As I said, these were interesting undergrad experiments, but they're far more useful as a learning experience in how to use wind tunnels for the experimenter than they are as information sources for aerodynamicists. Quote Marc J. ZeitlinBurnside Aerospacemarc_zeitlin@alum.mit.eduwww.cozybuilders.org copyright © 2023 Link to comment Share on other sites More sharing options...
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