Linked Questions
15 questions linked to/from Why do airfoil's trailing edges point downward?
58
votes
6
answers
16k
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Is a winglet better than an equal span extension?
Is there indisputable evidence that a winglet improves performance over an equal span extension? Please note: I am only interested in L/D improvements.
Winglets do improve roll performance, that is ...
- 230k
30
votes
10
answers
10k
views
What is ground effect?
We've all heard the "acts like a cushion of air" explanation tossed casually around by CFIs.
There's also plenty of books and reference materials that give a detailed, accurate, and complete ...
- 23.1k
48
votes
3
answers
20k
views
Why does supersonic flight detach airflow from a wing?
I've read in several answers to questions that when a wing passes the speed of sound the airflow will become detached from the craft towards the rear quarter of the wing (thus making things like ...
- 24k
24
votes
4
answers
6k
views
Why are heavy flaps better than just a bigger wing?
Flaps increase lift during landing and T/O. But when retracted, they do nothing. The space needed to stow the common fowler flaps can't be used for anything else - fuel or structure. Extended flaps ...
- 3,524
23
votes
4
answers
4k
views
Would an aircraft with contra-rotating propellers longer than the plane's wingspan be able to fly?
I enjoy taking the time to try and visualize how fictional aircraft might actually work in reality. Unfortunately there are some that seem highly impractical from an engineering student's point of ...
- 333
20
votes
5
answers
15k
views
What are the advantages of a Trimmable Horizontal Stabilizer?
What are the advantages of a Trimmable Horizontal Stabilizer (THS)? For example, a THS is used on some Airbus and Embraer aircraft. What is the most important advantage, and why don't some other ...
- 11.4k
12
votes
4
answers
4k
views
Why isn't there a single best airfoil for subsonic flight?
Why does airfoil used by modern subsonic aircraft (this is true for transonic airliners too) vary from plane to plane?
Haven't we figured out a single best airfoil shape, with the highest lift to ...
- 2,484
13
votes
3
answers
4k
views
Does static longitudinal stability require download on the tail?
After having encountered this meme too often for comfort, I ask myself today in order to have the possibility to explain the issue in detail.
- 230k
11
votes
3
answers
11k
views
How does the slotted flap work?
Slotted flap is an improved version of the plain flap, generating more lift (a fact I don't challenge). However the principle is air passing between the wing and the flap.
Source
This seems ...
- 70.9k
4
votes
2
answers
3k
views
Why are highly cambered airfoils rarely used in propellers or wings?
Highly cambered airfoils like the Seligs and Epplers are hardly ever used in propeller or wing sections. Why?
Does their performance reduce at high Re? Are they only adequate at low Mach, low Re?
...
- 411
7
votes
2
answers
3k
views
How often are slats used on airliners?
Are slats only used when there is a short runway or on all occasions?
- 197
5
votes
4
answers
2k
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Can this design provide more lift force than thrust from engine?
The problem is depicted in the picture:
Generally, why we don't use engine blow wings to fly? Can we use wind-tunnel-like wing to generate lift force?
Can it generate more lift than thrust? If it ...
- 51
7
votes
1
answer
5k
views
How can we determine the maximum camber and thickness for airplane wings?
I want to know if there are any standard factors for determining maximum wing camber and thickness for heavy and light airplanes?
I'm using an optimization process to find the best wing shape to ...
- 91
5
votes
3
answers
705
views
Why have high lift devices on both leading and trailing edge?
Trailing edge devices such as flaps increase lift by raising lift coefficient at s given AoA. Leading edge devices such as slats increase lift by raising stall AoA.
The former is nice because it ...
- 3,524
2
votes
3
answers
258
views
How does increasing camber increase lift coefficient?
How does increasing the camber of an airfoil (like the NACA 0018) increase its coefficient of lift?
You're just curving the airfoil; I don't see how that increases lift for a given angle of attack?
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