Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Downward-Curved Wings  
User currently offlinefaro From Egypt, joined Aug 2007, 1534 posts, RR: 0
Posted (2 years 9 months 4 weeks 1 day 20 hours ago) and read 3541 times:

Given a downward-curved wing, shaped like the upper section of a circle with a high mid-span curving down to low wing root and low tip, would this appreciably reduce induced drag resulting from leeward vortex mixing of air (from upper and lower wing surfaces) some distance from the aircraft? The premise is that you are ‘flexing’ the shape of the wing’s pressure trails in the opposite direction to that of the leeward vortex.

If yes, could such a wing shape be implemented with CFRP’s without too much weight penalty? What other drawbacks would it have?

Faro

[Edited 2011-10-07 00:40:08]


The chalice not my son
6 replies: All unread, jump to last
 
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 1, posted (2 years 9 months 4 weeks 1 day 13 hours ago) and read 3432 times:

Quoting faro (Thread starter):
Given a downward-curved wing, shaped like the upper section of a circle with a high mid-span curving down to low wing root and low tip, would this appreciably reduce induced drag

Not really. It would still have about the same Treftz plane pattern so, all other things being equal, it should have the same induced drag.

Quoting faro (Thread starter):
The premise is that you are ‘flexing’ the shape of the wing’s pressure trails in the opposite direction to that of the leeward vortex.

Without a CFD run I can't exactly picture how the flows would work out, but the major factor in determining induced drag is how far you stretch out the trailing vorticity...in this case, you have the same aspect ratio so the only difference in distance from the vortex sources and lift production is the thickness of the wing. That's not going to make much a of a difference, I think.

Quoting faro (Thread starter):
If yes, could such a wing shape be implemented with CFRP’s without too much weight penalty? What other drawbacks would it have?

You could certainly do it in CFRP and probably get something like comparable weight, but you'd have an absolutely attrocious ground clearance problem. Whatever you gained in efficiency would be more than lost in landing gear weight.

Tom.


User currently offlinetb727 From United States of America, joined Jun 2005, 1577 posts, RR: 9
Reply 2, posted (2 years 9 months 3 weeks 6 days 7 hours ago) and read 2954 times:

It probably wouldn't be very stable either.


Too lazy to work, too scared to steal!
User currently offlineluckyone From United States of America, joined Aug 2008, 2165 posts, RR: 0
Reply 3, posted (2 years 9 months 3 weeks 6 days ago) and read 2829 times:

Quoting faro (Thread starter):
If yes, could such a wing shape be implemented with CFRP’s without too much weight penalty? What other drawbacks would it have?

If what I'm picturing based on your description is correct, wouldn't it have rather tall landing gear? I'm envisioning the Tu-114, plus some!


User currently offline330guy From Ireland, joined Nov 2010, 453 posts, RR: 2
Reply 4, posted (2 years 9 months 3 weeks 5 days 12 hours ago) and read 2703 times:

Didnt Concorde have downward curved wings??

[Edited 2011-10-10 08:45:54]


Aircraft flown: a300/10/20/21/30/40, b727/37/47/57/67/, DC9, MD80-90, l1011, f50, atr42/72, shorts360, pc12
User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 5, posted (2 years 9 months 3 weeks 5 days 9 hours ago) and read 2650 times:

Quoting 330guy (Reply 4):
Didnt Concorde have downward curved wings??

Yes, although it was most pronounced just along the leading edge. And reallllly long landing gear.

Tom.


User currently offline2H4 From United States of America, joined Oct 2004, 8955 posts, RR: 60
Reply 6, posted (2 years 9 months 3 weeks 5 days 7 hours ago) and read 2592 times:
AIRLINERS.NET CREW
DATABASE EDITOR

Quoting tdscanuck (Reply 1):
You could certainly do it in CFRP and probably get something like comparable weight, but you'd have an absolutely attrocious ground clearance problem. Whatever you gained in efficiency would be more than lost in landing gear weight.

Unless one could adapt this Rutan gear design:


View Large View Medium
Click here for bigger photo!

Photo © Andrei Bezmylov




Intentionally Left Blank
Top Of Page
Forum Index

Reply To This Topic Downward-Curved Wings
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
A343 Vs. A346 Wings posted Mon Jul 18 2011 01:56:51 by na
Are The KC-390 Wings Large Enough? posted Fri May 20 2011 08:55:22 by 747400sp
The Evolution Of Flaps And Wings posted Fri Apr 15 2011 15:23:38 by SASMD82
Aircraft Wings/ Fuselage Footprint Comparisons posted Mon Feb 14 2011 08:45:36 by flyboy80
Higher Aspect-Ratio Wings: Why So Late In Coming? posted Fri Jan 21 2011 02:47:52 by faro
Very High Aspect Ratio Wings For Airliners posted Sun Aug 8 2010 05:31:48 by faro
787 Wings On A 777? posted Fri Jul 30 2010 00:38:33 by zvezda
Usaf Paints All Parts Of The Wings? posted Wed Jul 14 2010 22:41:58 by LASoctoberB6
Kink On Trailing Edge In Airbus Vs Boeing Wings posted Fri Jul 9 2010 01:04:37 by Starlionblue
Ice On Wings? posted Wed Mar 24 2010 20:04:39 by ag92

Sponsor Message:
Printer friendly format