Linked Questions

25
votes
2answers
5k views

How do insects decrease aircraft performance?

Is it true that insects hitting the fuselage could decrease aircraft performance and increase fuel consumption? Insects are small in mass. I think even a large amount of them accumulate on the ...
12
votes
4answers
3k 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 ...
23
votes
2answers
3k views

Is a golf ball surface a good idea for wings or fuselage?

I searched for an infamous golf ball question on this site but did not find any, so I guess it's time for one. Would a dimpled surface like a golf ball somehow improve the aerodynamics of an airplane?...
12
votes
2answers
4k views

Is airflow ever laminar in the boundary layer, near the wing leading edge?

I'm used to see images of the boundary layer over a wing like this: Transition from laminar to turbulent flow over the wing. Left: source, right: source As many others, these pictures indicate the ...
6
votes
2answers
2k views

Why are RC rotor blades different from helicopter blades?

Why do toy (RC) helicopters have curved flat surfaces and larger rotors on true helicopters have a solid aerofoil shape? If the rotor was mechanically strong enough to lift the desired weight, is ...
8
votes
3answers
707 views

Why does a turbulent boundary layer cause more friction drag than a laminar boundary layer?

From what I understand, friction is caused by viscosity and a bigger Reynolds number signifies lower viscosity. Thus, a higher Reynolds number(i.e. turbulent flow) results in lower friction. But, ...
5
votes
1answer
1k views

Does skin friction drag decrease with velocity?

The wings of subsonic planes have usually a very low surface area and aspect ratio as big as possible. However, in supersonic aircraft, wings with more wetted area (e.g delta wings) are used. Is this ...
7
votes
1answer
1k views

When should I use the global Reynolds number and when the local Reynolds number?

I know that for the wing, the Reynolds number is based on the MAC. This makes sense to me, as the boundary layer develops along the length of the wing. However, what kind of Reynolds number needs to ...
1
vote
1answer
481 views

How does drag change with Reynolds number?

If you want to scale down an airframe, i.e., for wind tunnel testing, you have to adjust for the Reynolds number. I want to ask if in case I forgot to adjust the Reynolds number, would the drag on the ...
2
votes
3answers
306 views

How does the power requirement change when weight and speed change?

Suppose I have an airplane with a certain weight M, which uses a certain amount of power P, to fly at a certain speed V. If I use the same airplane, but quadruple the weight (4xM) and double the ...
2
votes
1answer
256 views

What would be the power requirements and performance of a Scroggs-type delta-wing aircraft with a 250 cm span?

Roy Scroggs, a tailor, patented in 1917, US1250033, and in 1932 US1848578, a Delta Wing plan form machine 'Flying Dart', flight tested with an OX-5 engine, they say ...
3
votes
1answer
121 views

Why did a circular paper aeroplane of larger diameter fly further than one of a smaller diameter?

http://www.10paperairplanes.com/how-to-make-paper-airplanes/07-the-ring.html I am not an expert at this- just a high school student, so please explain this in fairly simple terms. Thank-you very much ...
0
votes
4answers
251 views

How does scaling of UAV size impact range?

Lets say you have two autonomous small aircraft, one with a wingspan of 200 cm and one with 400 cm. Both have the same general design. They are both optimized for travel distance on one full tank (gas ...