HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 25, 2013, 02:21 AM
Registered User
Joined Jan 2013
3 Posts
Discussion
Airfoil section for swept wings

could any one tell how the airfoil sections are oriented for swept wing.. if its perpendicular to quarter chord line then what will they do near the leading and trailing edge to complete the shape.. kindly reply..
boss03 is offline Find More Posts by boss03
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 25, 2013, 04:11 AM
An itch?. Scratch build.
eflightray's Avatar
South Wales U.K.
Joined Mar 2003
13,029 Posts
Have a look at some of the plans on this page -

http://www.unclewilliesplans.com/about39.html
eflightray is offline Find More Posts by eflightray
Reply With Quote
Old Jan 25, 2013, 11:08 AM
Registered User
Erich Preitler's Avatar
Austria [Europe, no Kangaroos ;-) ]
Joined Jan 2003
170 Posts
Quote:
Originally Posted by boss03 View Post
could any one tell how the airfoil sections are oriented for swept wing.. if its perpendicular to quarter chord line then what will they do near the leading and trailing edge to complete the shape.. kindly reply..
Its orientated in the direction of flight, that's what the air sees. More or less, ignoring effects of high sweep angles.
Erich Preitler is offline Find More Posts by Erich Preitler
Reply With Quote
Old Jan 25, 2013, 10:28 PM
B for Bruce
BMatthews's Avatar
The 'Wack, BC, Canada
Joined Oct 2002
11,308 Posts
Boss, it's been done both ways with decent results.

When swept wings first showed up the norm was to set the airfoil ribs at 90 degrees to the quarter chord line, or near enough to it. This results in a elongated airfoil when seen as a direct "inline" direction. Yet it is how many of the early swept wing jets were built. Even the ribs themselves were angled like that under the skins in many cases.

These days we don't seem to do this as much..... or at all. On our models the airfoils are used with the proper shaped ribs parallel to the aircraft center line rather than angled to be perpendicular to the quarter chord line.

Now looking at the wording of your question it seems like you think this means that the airfoils "S" turn to be inline at the leading and trailing edges and angled at the quarter chord line. Nope, it don't work like that. It's all or nothing. You either go with the airfoil parallel to the aircraft center line or you angle the WHOLE rib to the quarter chord line.

With many of our models the wing is an open frame style. Angling the ribs would produce a lot of wobbles in the flow direction. So we modellers tend to choose the option of the proper name brand airfoil done as ribs which are parallel to the center line of the aircraft.
BMatthews is online now Find More Posts by BMatthews
Reply With Quote
Old Jan 26, 2013, 12:44 AM
Registered User
Joined Jan 2013
3 Posts
Thanks for all for your reply... and also there is correction in the question... its not about leading edge and trailing edge.. if section is oriented perpendicular to chord, what they will do near root and tip..
i need this thing because i am going to calculate aerodynamic loads acting on the sweep wing using sectional data available..i am little bit confused while taking section whether it should be along the flight axis or perpendicular to chord..
kindly reply..
boss03 is offline Find More Posts by boss03
Reply With Quote
Old Jan 26, 2013, 09:58 AM
Grad student in aeronautics
United States, GA, Atlanta
Joined Oct 2010
444 Posts
Flight axis. What you're talking about is called strip theory and it becomes less accurate the more sweep you have because of spanwise flow.
DPATE is online now Find More Posts by DPATE
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Airfoil section for swept wings shaneyee Modeling Science 18 Jan 25, 2013 11:34 AM
Question swept wing airfoil(s) for light slope lift?? dbatey Slope 4 Jul 13, 2008 05:53 PM
Discussion Airfoil for low Re swept wing? JetPlaneFlyer Modeling Science 8 Mar 11, 2008 08:14 PM
Discussion Airfoil for low Re number swept wing? JetPlaneFlyer Flying Wings 2 Mar 10, 2008 10:22 AM
Airfoil section for flying wing Chippie Foamies (Kits) 5 Sep 07, 2003 03:54 AM