Linked Questions

11
votes
3answers
5k views

What is the purpose of a wing Yehudi? [duplicate]

Apart from covering the landing gear leg, the Yehudi also increases the wing root cord which allows the build height for the root to increase for the same wing relative thickness. This is useful as ...
20
votes
3answers
2k views

Why is the trailing edge sweep angle smaller at the wing root?

Many airliners have a distinct unswept part at the wing root at the trailing edge. See for example this image from Wikimedia of a B737-400. Other examples include the B777, A320, Embrear 145, and ...
8
votes
4answers
14k views

Where is the spanwise flow? How does the span wise flow point the air towards the wingtip?

If you search Google for span wise flow, the first result under the pictures tab is a image of a wing with the span wise flow at the trailing edge: (Source) If you look at some other photos you ...
2
votes
5answers
2k views

Do horizontal stabilisers provide any lift?

Do jumbo and smaller airliners' horizontal stabilizers provide any lift? Apart from maintaining the aircraft's angle of attack, can they perform the dual function that includes adding some lift as ...
9
votes
1answer
1k views

Are there any fly-by-wire airliners with negative or near-neutral pitch stability?

Are any modern commercial airliners with fly-by-wire flight control systems designed with negative or near-neutral pitch stability so that they can take advantage of the capability of such systems to ...
4
votes
1answer
2k views

What is the pressure on the pressure side in relation to the freestream?

The following [edited] images are from a network post: The top image states on the pressure side, the pressure is greater than the freestream. On the bottom image, the $C_p$ varies. According to ...
1
vote
1answer
331 views

Is/why isn't the Antonov 124 to 225 wing upgrade method common?

I'm told that wing redesigns (edit: for tapered, swept wings) are difficult, so variants of a model often do with a common wing optimized for the middle member. But then I read the following: Based ...
2
votes
1answer
509 views

Why does the effective alpha/CL increase at wingtip of swept wing?

If anybody could explain this in an intuitive way I'd really appreciate it. I haven't been able to find a clear answer on this. I understand that the increase in effective AoA/CL and the spanwise flow ...
1
vote
2answers
119 views

What is the typical wing twist angle at the wing tip for a commercial jet?

I'm trying to find this information for commercial jets. It is nowhere to be found. Does anyone know typical values?
2
votes
1answer
188 views

Which airfoil to use for high subsonic flight?

I am desigining an aircraft, which shall fly up to Mach=0.9 in cruise flight in an altitude of 10 km. So when I think of which airfoil to choose, I have to consider aspects like max. lift coefficient ...
2
votes
2answers
187 views

Swept back wing theory

I'm a beginner in airfoil design. I just came across swept-back wings. There is a point that I couldn't understand that theory. Why is the only perpendicular component of the airflow to the wing(...
2
votes
1answer
150 views

Do commercial passenger airplanes have cambered airfoils?

It seems to me that they logically would, since they have no need to fly upside down like an aerobatic plane would (so they would not need a symmetric airfoil for any conceivable reason). That being ...
1
vote
1answer
106 views

Difference in lift generation for a swept wing and straight wing in subsonic condition

Would there be any differences in lift for a straight wing and swept wing (front or back) with the same airfoil cross section, same chord length, same wing span, and same area when flying in subsonic ...
1
vote
1answer
64 views

Does the quarter-chord-angle rule still hold for wings with very long chords or large differences between leading- and trailing-edge sweep angles?

For most fixed-wing aircraft, the effective wing-sweep angle (i.e., the angle that the aircraft aerodynamically behaves like its wings are swept at) is equal to the angle of the quarter-chord line (...