Winglet aerodynamics
Winglet aerodynamics
(OP)
Hi all
I am new here and have just done a search to see if I could find any posts on winglets. Although I did find and read the post they did not really answer my question.
My question is how has fitting blended winglets affected the basic flight performance of an aircraft in the glide and turn..
Any answers would be gratefully received as this was a question I was asked and could not fully answer and it is annoying me now.
Thanks
I am new here and have just done a search to see if I could find any posts on winglets. Although I did find and read the post they did not really answer my question.
My question is how has fitting blended winglets affected the basic flight performance of an aircraft in the glide and turn..
Any answers would be gratefully received as this was a question I was asked and could not fully answer and it is annoying me now.
Thanks





RE: Winglet aerodynamics
RE: Winglet aerodynamics
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Winglet aerodynamics
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
RE: Winglet aerodynamics
see http://en.wikipedia.org/wiki/Wingtip_device
RE: Winglet aerodynamics
I haven't heard of adding winglets to improve climb rates. This is usually such a small portion of a mission. Maybe for something like Scaled Composite's Space Ship One where half of it's mission was climb profile and the other half you want high drag anyway.
As for lateral stability, only if it's located well behind the COG like on the Rutan canard designs.
Most winglets are found on long distance commercial jet aircraft and gliders. In both cases they are optimized for cruise, or in the case of gliders the best L^2/D.
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
RE: Winglet aerodynamics
The lateral stability bit comes up on the 747 Space Shuttle comments, but also in the glider section, and yes, regarding Rutan canard designs.
RE: Winglet aerodynamics
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
RE: Winglet aerodynamics
RE: Winglet aerodynamics
They can be pitched slightly outward to reduce both bending moment on the wing and counter the wing tip vorticies.
The fact is, winglets have a sweetspot in regards to air speed and flight profile. If I recall correctly there was some attempt to construct a trimmable winglet so you could expand that sweetspot.
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
RE: Winglet aerodynamics
It does this by reducing wing tip vortex which causes loss of lift at tips of straight wings.
RE: Winglet aerodynamics
"... which causes loss of lift at tips of straight wings." no; the wing tip vortex causes drag (= induced drag).
IMHO
RE: Winglet aerodynamics
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Winglet aerodynamics
I don't think roll has much effect. Side slip though...
Tom Moritz
Mechanical Engineer
US Bureau of Reclamation
RE: Winglet aerodynamics
Excellent engineering references on winglets (free download):
http://www.aiaa.org/content.cfm?pageid=2 search: winglet
>>MANY winglet design reports pop-up including theory, structures; dsgn for heavy acft, for GA acft, for sailplanes, etc...
http://www.dtic.mil/dtic/search/tr/index.html search: winglet
Several good reports are available for public access....
Regards, Wil Taylor