Linked Questions

25 votes
2 answers
7k 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 ...
TBBT's user avatar
  • 1,842
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 ...
Francis L.'s user avatar
  • 2,514
9 votes
5 answers
3k views

Why do newer engines have such wide fan blades?

Every treatise I read about propellers/fan blades/wings states that long, thin wings are more efficient than wide stubby ones. So why is it that the blades in high-bypass turbofan engines fitted to ...
Buk's user avatar
  • 93
24 votes
2 answers
4k 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?...
DrZ214's user avatar
  • 17.7k
16 votes
2 answers
10k views

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

I often see images of the boundary layer over a wing indicating the airflow is laminar over the first portion of the wing: Transition from laminar to turbulent flow over the wing. Left: source, right:...
mins's user avatar
  • 73.2k
8 votes
5 answers
3k views

What factors influence the maximum speed of an airship?

I'm interested in learning about the physics of airships; in particular, how you determine an airships maximum speed. For example, the Hindenburg topped out at about 80 mph. The ship itself weighed ...
RetailPleb's user avatar
10 votes
3 answers
955 views

Why don't smaller powered airplanes have better lift-to-drag ratios?

Many airliners have LDRs near 20, and it sounds like the electric Eviation Alice may have an LDR of 24 at 240 kts, but many small planes typically have LDRs of only 8-10. It seems like they could ...
Spencer Ahrens's user avatar
8 votes
3 answers
5k 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, ...
Zaber's user avatar
  • 359
7 votes
2 answers
3k 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 ...
C Aerospace's user avatar
5 votes
1 answer
2k 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 ...
user15037's user avatar
2 votes
3 answers
503 views

Is the ideal airfoil concave on the underside?

Virtually all airplane wings are convex on both the top and at least part of the bottom. But thus convexity on the bottom creates suction which reduces lift. I can only think of two reasons to have it:...
Abdullah is not an Amalekite's user avatar
2 votes
3 answers
2k 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 ...
Björn Morén's user avatar
8 votes
1 answer
2k 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 ...
ROIMaison's user avatar
  • 7,157
1 vote
1 answer
1k 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 ...
Francis L.'s user avatar
  • 2,514
1 vote
2 answers
1k views

Will increasing the wing area result in higher aircraft range?

Intuitively, it seems that a low loading (large area) wing will allow to climb higher from the start, thus increasing true air speed and range. At the same time, a low loading wing also calls for a ...
Electric Pilot's user avatar

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