Linked Questions

37
votes
3answers
9k views

How does an aircraft form wake turbulence?

This question discusses how wake turbulence can affect planes flying in formation. It got me wondering, how do aircraft (the wings in particular) form wake turbulence to begin with? It can't be as ...
15
votes
4answers
6k views

How high does the ground effect last?

Up to which height is the ground effect still significant enough to be taken into account? Would this height be sufficient to actually fly above the ground, overcoming at least trivial obstacles like ...
11
votes
3answers
8k views

Does the downwash created by induced drag increase or decrease lift?

According to the theory I know, lift is produced by accelerating air downwards at the trailing edge (downwash). Hence, as downwash increases so does lift. Induced drag is due to vortices at the wing ...
9
votes
2answers
2k views

Is induced drag essentially nothing more than a specific type of form drag?

If I were standing outside on a windy day holding a flat rectangular object such as a food tray up in the wind, orthogonal to the direction of flow, the drag created would be classified, mostly, as ...
6
votes
4answers
912 views

Can wing-tip vortices be reduced/eliminated with a rear-facing propeller near the wing-tip?

Let's say we have a propeller-driven aircraft in the pusher configuration (rear-facing propellers). If we could somehow put an engine at the wing tip (ignoring structural concerns), and maybe make the ...
11
votes
2answers
3k views

How is the induced drag calculated for a wing with elliptical planform?

How is the induced drag calculated for a wing with elliptical planform ? Is this wing shape the most efficient ?
6
votes
2answers
5k views

Why does the vortex created by wing affects its own angle of attack?

According to potential flow theory, we know that the lift generated by the wings is due to the vortex it creates. In case of a 3D finite wing, there is also a span wise flow due to tip leakage from ...
5
votes
2answers
2k views

Why is induced drag less on a high span wing?

I have a basic question and sorry if it is a well known fact. I understand that the induced drag is due to the tip vortices changing the effective angle of attack (downwash). I searched some ...
7
votes
1answer
504 views

Do software simulations and wind-tunnel tests accurately predict Cd and Cl in real-world conditions?

Will the lift coefficient (Cl) and drag coefficient (Cd) I obtain by using software simulations or subsonic wind-tunnel tests be the same as on an actual aircraft while cruising? Or will there be some ...
1
vote
2answers
332 views

How does wing aspect ratio influence lift and drag?

I know simmilar questions are all over the internet (and this website too), but there's one thing that i just cannot comprehend and none of the articles i read could explain it properly. According to ...
1
vote
1answer
320 views

Why does each part of span not produce equivalent downwash?

I know that it is associated with Prandtl lifting-line theory and that ideal elliptical wing actually meets the condition of my question. Unfortunately I am not good at fluid dynamics and I would like ...
1
vote
1answer
203 views

Why is subsonic lift at 25% of chord? [duplicate]

I pretty much understand the way a wing works and the different ways of explaining it, what I don´t understand is why the lift on a subsonic wing manifest itself at the 25% chord.... The 50% chord ...