coyote Posted September 29, 2008 Share Posted September 29, 2008 Did one of you tried to use milar tape to seal the gap between canard and elevator on a GU profile? Is there any positive effect ? From a theoritical point of view, depending on the design, the gap may be used to blow the upper surface under high angle of attack to reattach the flow, then it may be detrimental to use some. If it is just a "mechanical" gap to allow the elevator movement, then it may be positive to seal ... I would clearly clasify the GU canard in the second category ... but i'm not 100% sure, and i feel lot of you guys may had the idea and have made the test already ! Quote Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted September 29, 2008 Share Posted September 29, 2008 ... the gap may be used to blow the upper surface under high angle of attack to reattach the flow, then it may be detrimental to use some.Bingo. The canard/elevator (GU or Roncz) is actually a slotted flap airfoil. The airflow through the slot/gap is critical to it's operation. If it is just a "mechanical" gap to allow the elevator movement, then it may be positive to seal ...This is NOT the case. I would clearly clasify the GU canard in the second category ...You'd be wrong. but i'm not 100% sure, and i feel lot of you guys may had the idea and have made the test already !It is unlikely that anyone who gap sealed their canard (GU or Roncz) would be able to get off the ground for any flight testing. Removing attached flow over the top of the elevator would be a very bad thing. Quote Marc J. Zeitlin Burnside Aerospace marc_zeitlin@alum.mit.edu www.cozybuilders.org copyright © 2024 Link to comment Share on other sites More sharing options...
steve Posted March 31, 2009 Share Posted March 31, 2009 i was looking at 4 dragons -flys and if you looked just right, you could see that the wings of one was angled 2" more then the plane next to it. then a guy said thats nothing, look and the wing placement....3" off. both owners think theres is in the right place (just kidding), both planes seem to fly the same. both had GU wings Quote Steve M. Parkins Link to comment Share on other sites More sharing options...
longez360 Posted March 31, 2009 Share Posted March 31, 2009 Gap seals on the canard (slotted flap) are repeatedly stated as not acceptable in the canard pusher newsletters. For those who have not read and absorbed that material, please make yourself familiar before building and or operating one of these aircraft. On another slightly separate subject, cove lips : Klaus Savier does have a cove lip (small triangular shaped peice) on the underside of his modified Roncz R1145MS aerofoil. It doesnt cover the gap, but certainly changes the flow to the slotted flap. The aerofoil does have a lower Cd as stated. See: video: Report: http://pagesperso-orange.fr/scherrer/matthieu/aero/papers/Savier_Canard.pdf Quote Cheers, Wayne Blackler IO-360 Long EZ VH-WEZ (N360WZ) Melbourne, AUSTRALIA http://v2.ez.org/feature/F0411-1/F0411-1.htm Link to comment Share on other sites More sharing options...
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