Iam asked in Cars & TransportationAircraft · 2 months ago

Why do airplane wings have blunt front ends.?

When you see images of airplane wings in profile they have a blunt front end and a sharp pack end. Why not the reverse? It would make more sense to have a wing that cuts through the air and then pushes it down to generate lift. Can anyone explain the aerodynamics behind it?

8 Answers

  • fuzzy
    Lv 6
    2 months ago

    Some basics theory posted by others.

    I'll simply add - many many hours of work by engineers & scientists in wind tunnels have shown that is what works best at the speed most aircraft works at.

    (Fror reference the actual shape of the airfoil for a Cessna & a 747 is different because they fly at different speeds.

  • Scott
    Lv 7
    2 months ago

    Google "airfoil" to find the explanation.

  • Anonymous
    2 months ago

    A blunt shape is actually the most aerodynamic for the speeds most planes fly (below the speed of sound). 

    A sharper leading edge would actually create more drag. It would also make for some nasty stall and spin characteristics. 

    Sharp trailing edges are critical for drag reduction as well as lift production. 

  • 2 months ago

    I could explain at length, but given that you have this question implies that most theoretical concepts would require additional explanations, so I will go with the intuitive concept.

    A wing works by having lower pressure on the top, this vacuums up the wing, essentially.

    As it turns out, you can always punch through the air in a blunt manner in the front, but for the read it is a different story as air has viscosity, that means it sticks--of course, it is orders of magnitude less than molasse, but it still sticks a little. So, what you want is for the air to let go of the wing as gently as possible at the rear, so you have to do that very progressively, this to avoid messing the low pressure the wing established. Imagine that there is a spoon in water and you want to take the spoon out with minimal splash, you will turn the spoon sideways to have the pointiest shape possible, and will remove the spoon as gently as possible.

    Returning the air to the environmental pressure and speed at the rear of the wing cannot be done too fat or else the flow will detach, and the wing will stall (that is losing the capacity of retaining low pressure on the top of the wing, which means the wing cannot provide lift anymore)

    So far so good?

    But, you will ask, how about the front? Wouldn't it benefit from having a pointy end? Not as much, because you do not care about the air that is in front, as it will always manage to get out of your way, going either up or down, until you go supersonic (and by definition, the ability of air to move when pushed is limited by the speed of sound, which is actually the speed with which a pressure wave can propagate). But there is the issue of having an extra long front end if you were to make it pointy, which would require more metal, would be heavy, would have more surface area for the air to stick to (creating drag, which you try to avoid), and would give you no aerodynamic benefit.

    By the way, a wing will have its center of pressure 1/4 of his chord in subsonic flight, meaning that it is 1/4 of the length forward of the location where the lift is centered, and 3/4 aft; this would indicate a need to make the front 1/3 the size of the rear. At supersonic speed, the center of lift moves to the middle of the wing.

    This shape (somewhat blunt at the front, tear drop shaped at the rear) is the one that minimizes drag, that is why that is the shape of fish and submarine, blimps and aircraft fuselage. It is always more pointy at the rear.

    And if you ever get close enough to a jet liner wing, you can check the very rear end. It looks pointy, but up close, you will notice that the very tip is blunt, about 1 cm high. The reason for that is that, at the rear of the wing, the boundary layer (the air that sticks to the wing) is about that thick, so how you detach it, with a point or a blunt end, makes no aerodynamic difference, but you save the material to make the pointy tip. 

    And two idiots down-thumbing my answer will not change the fact that it is accurate. Comeback when you have a master in aerospace engineering.

    Source(s): I am an aerospace engineer, it should show a little...
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  • Anonymous
    2 months ago

    The front end is not blunt, more like oval.  It is designed that way to "turn' the fluid or air.

  • Pearl
    Lv 7
    2 months ago

    maybe it makes the plane fly better

  • 2 months ago

    Your design would reduce drag but the design used creates more lift. I think you will agree that lift is VERY important when you are flying.

  • 2 months ago

    basically the air moving over the top of the wing takes longer to pass the wing than the air flowing over the bottom of the wing.  This causes lift.


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