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Science Forum

  1. 26 May '09 09:19
    I heard about how owls can fly silently because their leading edge of their wings have specialised feathers that dampen down air turbulence. I have also heard that one of the main complaints people have about having a wind farm or wind rotors near their homes is the constant swishing noise the blades on the wind rotors make as they go around. So here is my simple idea; why not put similar feather-like structures which are on owl wings on the blades on wind rotors to at least eliminate the noise problem?
    As a small side benefit, the reduced air turbulence would mean that bats flying past it would be less likely to be injured by violent air turbulence that the wind rotors would normally otherwise generate.

    I tried see by searching the net if anyone else has looked into this idea but couldn’t find any examples BUT I found examples of a similar ideas to this one but with different applications that at least prove the idea IS feasible:

    By mimicking the leading edge of an owl’s wing on roof rack for cars:

    http://www.betterbydesign.org.nz/news-and-resources/design-news/news-details?objId=efb77706-6205-4568-89da-dd329317545c

    “…By eliminating noise and reducing drag the roof rack also leads to 2-3% less fuel consumption…”

    Also, By mimicking the leading edge of an owl’s wing on an air-conditioning fan blade:

    http://peakenergy.blogspot.com/search?q=serrated+edges+of+the+owl%27s+wing

    “…an air-conditioning fan blade that mimics the serrated edges of the owl's wing, reducing noise and energy use…”

    Thus I conclude from the above not only would applying this idea to wind rotor blades would result in them being less noisy (and less dangerous to bats) but would make wind rotor more energy efficient! -I think somebody should definitely look into this.
  2. Standard member uzless
    The So Fist
    26 May '09 21:11
    Originally posted by Andrew Hamilton
    I heard about how owls can fly silently because their leading edge of their wings have specialised feathers that dampen down air turbulence. I have also heard that one of the main complaints people have about having a wind farm or wind rotors near their homes is the constant swishing noise the blades on the wind rotors make as they go around. So her ...[text shortened]... ould make wind rotor more energy efficient! -I think somebody should definitely look into this.
    wind hitting the blade is what turns the blade. If you make it easier for the wind to slip off the blade, don't you decrease the efficiency of the blade in all but constant winds?
  3. 27 May '09 03:35
    Originally posted by Andrew Hamilton
    I heard about how owls can fly silently because their leading edge of their wings have specialised feathers that dampen down air turbulence. I have also heard that one of the main complaints people have about having a wind farm or wind rotors near their homes is the constant swishing noise the blades on the wind rotors make as they go around. So her ...[text shortened]... ould make wind rotor more energy efficient! -I think somebody should definitely look into this.
    OK, go ahead and make it then.

    I'll be expecting to see it on the market next year.
  4. 27 May '09 04:42
    Originally posted by uzless
    wind hitting the blade is what turns the blade. If you make it easier for the wind to slip off the blade, don't you decrease the efficiency of the blade in all but constant winds?
    I isn't the wind hitting the blade that makes the blade move. It's the under-pressure of the other side that does it.
    If the wind goes undisturbed, it can generate more under-pressure, and can produce more energy.
    The more silence, the more energy, roughly said. Ask any sailplane pilot.
  5. 27 May '09 10:02 / 7 edits
    Originally posted by mlprior
    OK, go ahead and make it then.

    I'll be expecting to see it on the market next year.
    …OK, go ahead and make it then..…

    I obviously don’t have the practical means to do that because I have no easy access to a laboratory/workshop and I don’t even have sufficient qualifications to be employed to do the research.
    I would therefore not be planning to make money from the idea myself (no matter how much I would like to) but rather would just hope that others that are in a position to do the research would develop the idea and thus create a significant improvement in wing power technology which would benefit us all.

    Seriously, can anyone tell me who I should contact for this? -can anyone give me an appropriate web link? -I want to really make this happen!
  6. 27 May '09 10:18 / 1 edit
    Originally posted by uzless
    wind hitting the blade is what turns the blade. If you make it easier for the wind to slip off the blade, don't you decrease the efficiency of the blade in all but constant winds?
    …wind HITTING the blade is what turns the blade. If you make it easier for the wind to SLIP OFF the blade..…(my emphasis)

    FabianFnas is perfectly correct in what he said. But, putting it too simplistically and a bit vaguely if you wish, it is the wind “slipping off” the blade (because that causes a difference in air pressure between the two sides of the blade) rather than the wind “hitting” the blade” that causes the blade to turn.
  7. Standard member Thequ1ck
    Fast above
    27 May '09 13:01
    Originally posted by uzless
    wind hitting the blade is what turns the blade. If you make it easier for the wind to slip off the blade, don't you decrease the efficiency of the blade in all but constant winds?
    hahahahah LMFAO gets one of my all too rare recs
  8. Standard member uzless
    The So Fist
    27 May '09 18:26
    Originally posted by FabianFnas
    I isn't the wind hitting the blade that makes the blade move.
    Semantics. The low pressure can't be formed unless the wind goes over the blade. Apologies for not being scientific in my description.

    The car carrier produced less drag. Ok, but keep it mind it is being propelled by a car. The windmill isn't already moving. It's relying on the wind to propel the blades.

    I'd be interested to see if the owl-like structure would increase or decrease the low pressue created as the blade is turning.
  9. 27 May '09 19:23 / 2 edits
    Originally posted by uzless
    Semantics. The low pressure can't be formed unless the wind goes over the blade. Apologies for not being scientific in my description.

    The car carrier produced less drag. Ok, but keep it mind it is being propelled by a car. The windmill isn't already moving. It's relying on the wind to propel the blades.

    I'd be interested to see if the owl-like structure would increase or decrease the low pressue created as the blade is turning.
    …The car carrier produced less drag. Ok, but keep it mind it is being propelled by a car. The windmill isn't already moving. It's relying on the wind to propel the blades.
    ..…


    Why should that make a difference to the air turbulence that is the cause of the drag?

    ….I'd be interested to see if the owl-like structure would increase or decrease the low pressure created as the blade is turning.
    ...…


    doesn’t the leading-edge feathers of an owl’s wing increase the overall pressure difference (by reducing random air turbulence) created as the wings flap?
  10. 27 May '09 19:39
    Originally posted by uzless
    Semantics. The low pressure can't be formed unless the wind goes over the blade. Apologies for not being scientific in my description.

    The car carrier produced less drag. Ok, but keep it mind it is being propelled by a car. The windmill isn't already moving. It's relying on the wind to propel the blades.

    I'd be interested to see if the owl-like structure would increase or decrease the low pressue created as the blade is turning.
    Semantics? Well, I don't think so, the yet more correct way to express the same thing is that laminar flow reduce drag, and the most laminar flow is totally silent.

    We are not talking about the windmill problem, are we? I want to keep off that discussion.
  11. 27 May '09 22:21
    Originally posted by Andrew Hamilton
    [b]…OK, go ahead and make it then..…

    I obviously don’t have the practical means to do that because I have no easy access to a laboratory/workshop and I don’t even have sufficient qualifications to be employed to do the research.
    I would therefore not be planning to make money from the idea myself (no matter how much I would like to) but rath ...[text shortened]... ntact for this? -can anyone give me an appropriate web link? -I want to really make this happen![/b]
    I don't know who to contact.

    I'm a research person myself, but more with Chemistry.

    I also fly airplanes and have seriously thought about creating an experimental aircraft based on biomimetrics using a sharkskin design.
    The denticles on a shark's skin creates a turbulent flow around the shark's body as it flows through the water, this allows it to go faster than it would without them. http://firstbasefrc.autodesk.com/ama/orig/competition/975/675/10-shark-skin.jpg


    As far as the wind turbine design, I'm not sure. Sorry.
  12. 28 May '09 05:41
    Originally posted by FabianFnas
    We are not talking about the windmill problem, are we? I want to keep off that discussion.
    Sorry.
    It's the threadmill problem I don't want to discuss. Windmill is fine.
    Again: Sorry.
  13. Standard member uzless
    The So Fist
    28 May '09 14:30
    Originally posted by mlprior
    I don't know who to contact.

    I'm a research person myself, but more with Chemistry.

    I also fly airplanes and have seriously thought about creating an experimental aircraft based on biomimetrics using a sharkskin design.
    The denticles on a shark's skin creates a turbulent flow around the shark's body as it flows through the water, this allows it to go ...[text shortened]... n/975/675/10-shark-skin.jpg


    As far as the wind turbine design, I'm not sure. Sorry.
    The Soviets experimented with ultra fast torpedoes. At the front of the torpedo it would inject tiny bubbles into the water just ahead of the torpedo. When the torpedo hit the bubbles, it encountered less resistance since the bubbles pushed aside the water and this enabled the torpedo to move through the water much faster.
  14. 29 May '09 03:34
    Originally posted by uzless
    The Soviets experimented with ultra fast torpedoes. At the front of the torpedo it would inject tiny bubbles into the water just ahead of the torpedo. When the torpedo hit the bubbles, it encountered less resistance since the bubbles pushed aside the water and this enabled the torpedo to move through the water much faster.
    The Soviets experimented with a lot of things that we don't speak of in public.