Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Wings with holes

  1. Apr 29, 2008 #1

    wolram

    User Avatar
    Gold Member

    I am sure i read about experiments with wings drilled with many tiny holes, the idea i think was to break up the boundary layer, did any thing come of out of these experiments?
     
  2. jcsd
  3. Apr 29, 2008 #2

    Danger

    User Avatar
    Gold Member

    I suspect that you're thinking of 'laminar-flow skin'. If so, air is pumped out through the holes in order to prevent a boundary layer from forming. That's all that I've got; Fred can probably help you out a lot more.
     
  4. Apr 29, 2008 #3

    turbo

    User Avatar
    Gold Member

    I don't know about that, Woolie, but I have a friend who has been the National champion in his drag-racing class (he runs a classic 340 Duster) and is always competitive. He claims that if you polish intake manifolds, it supports laminar boundary-flow and that causes drag. He has his intake manifolds roughened to some arcane standards that he and his head-work specialist know, and he claims that the micro-turbulence in the air/manifold boundary acts like "little ball-bearings" as he puts it, to allow the bulk of the intake air to get to the cylinders with as little drag as possible. It makes sense, because if you can get the air rolling in little tiny pockets and the air is rolling to counter to the bulk air flow just at the boundary, and is rolling IN the direction of the bulk air flow just a little bit away from the air-manifold boundary, the bulk of the air would get a little boost from the rotating air cells near the boundary. He races in a class that is very restrictive about the modifications that are allowed to the car, so every little secret helps.
     
  5. Apr 29, 2008 #4

    russ_watters

    User Avatar

    Staff: Mentor

    It actually goes both ways depending on how you are looking to do it. I have to run, but here's a link to the opposite:
    http://en.wikipedia.org/wiki/Blown_flap
     
  6. Apr 29, 2008 #5

    wolram

    User Avatar
    Gold Member

    I found at my expense in time that a sand blasted cylinder head gave improved pick up over one i had spent hours polishing, then found out it was shape that really mattered
    and the surface is best left (cast).
     
  7. Apr 29, 2008 #6

    wolram

    User Avatar
    Gold Member

    Is this like a venturi effect?
     
  8. Apr 29, 2008 #7
    It's not quite the same thing (but sorta close) and I don't have a source at the moment (I needed to use my neuron today and now it's over at the National Aviary resting), but the US Navy was looking at doing something like this for torpedoes.
     
  9. Apr 29, 2008 #8
    Last edited: Apr 29, 2008
  10. Apr 30, 2008 #9
    All these methods don't really break up the BL but rather energize it so it will stay attached longer. This can be done by using VG's like frogman says but for high curvature area's this may not seem to be enough so holes are common think of the triple slotted flaps on the trailing edge of a 747.
     
  11. Apr 30, 2008 #10

    FredGarvin

    User Avatar
    Science Advisor

    VGs always seem like the first line of defense for separation prevention. However, I believe Wolly is referring to vacuum assisted BL control that NASA was working on. Honestly, I haven't heard anything lately. I'll have to see if I can dig up any results or reports.
     
  12. Apr 30, 2008 #11

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    An aero professor and some grad students at my university were developing a wing that instead of using control surfaces used tons of tiny holes on the top and bottom of the wing of the aircraft. Using an internal pump and ducting to the holes, they directly changed the pressure above/below the wing to control the aircraft's flight, taking over control which would normally be accomplished through control surfaces on the wing.

    From what I understand, they were able to create a working testbed out of an R/C airplane. It is a very interesting sounding technology.
     
  13. Apr 30, 2008 #12

    Mech_Engineer

    User Avatar
    Science Advisor
    Gold Member

    Last edited: Apr 30, 2008
  14. May 1, 2008 #13

    minger

    User Avatar
    Science Advisor

    We are doing similar things at my university as well. However, our flow control is done on missiles. Aside from holes (I don't believe ours are pumped though), they have a lot of other methods for flow control which are pretty neat.
     
  15. May 1, 2008 #14

    Danger

    User Avatar
    Gold Member

    Please do! I'm totally unfamiliar with this, and it sounds fascinating.
     
  16. May 1, 2008 #15
    The holes in the wings clogged too easily to make the system worthwhile.
     
  17. May 2, 2008 #16

    wolram

    User Avatar
    Gold Member


    Hi pantaz, did you work with this idea, if so do you have any data.
     
  18. May 2, 2008 #17
  19. May 3, 2008 #18

    wolram

    User Avatar
    Gold Member

    Thank you pantaz.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Wings with holes
  1. Rogallo Wing (Replies: 0)

  2. Finite Wings (Replies: 1)

  3. Aircraft Wings (Replies: 2)

  4. Wing weights (Replies: 5)

  5. Wing spar location (Replies: 1)

Loading...