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BigWheel design creates amazing amounts of lift! Maybe?

Discussion in '* Scratch Built Section *' started by kram242, Feb 20, 2009.

  1. kram242

    kram242 Administrator Staff Member

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    Amazingly enough, this question is still argued in many places, from elementary school classrooms all the way up to major pilot schools, and even in the engineering departments of major aircraft companies. This is unexpected, since we would assume that aircraft physics was completely explored early this century. Obviously the answers must be spelled out in detail in numerous old dusty aerodynamics texts. However, this is not quite the case. Those old texts contain the details of the math, but it's the *interpretation* of the math that causes the controversy. There is an ongoing Religious War over both the way we should understand the functioning of wings, and over the way we should explain them in children's textbooks.


    * The physics explanation, NEWTONIAN or ATTACK ANGLE: wings are forced upwards because they are tilted and they deflect air.

    * The popular explanation, PATH-LENGTH or AIRFOIL-SHAPE: wings do not deflect air, instead they are sucked upwards because the "airfoil" shape has a longer surface on top


    Bernoulli's principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy.
    Fluid particles are subject only to pressure and their own weight. If a fluid is flowing horizontally and along a section of a streamline, where the speed increases it can only be because the fluid on that section has moved from a region of higher pressure to a region of lower pressure; and if its speed decreases, it can only be because it has moved from a region of lower pressure to a region of higher pressure. Consequently, within a fluid flowing horizontally, the highest speed occurs where the pressure is lowest, and the lowest speed occurs where the pressure is highest

    Introducing the BigWheel. A crazy design idea for an aircraft that uses the Bernoulli's principle AKA(Equal Transit Time explanation) to create lift from its own propulsion system pushing the airflow under the aircraft faster than that of the air moving over the aircraft. The aircraft itself is a lifting body designed to be the airfoil itself

    The motor will be in the center of the design with a reduction belt pulley system connected to the blower shaft turning both blowers

    Some of these quotes found on the net


    I would like to hear your input before I finish this build and test it out this summer :D
    What do you think will it work? Why and why-not




    Attached files [​IMG] [​IMG] [​IMG] [​IMG] [​IMG]
     
  2. ssmeier

    ssmeier New Member

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    Maybe we will get to add your "BigWheel" to the bumblebee (aerodynamically not able to fly) and the Kline-Fogleman airfoil (contrary to Bernoulli's Theorum).

    http://www.rcgroups.com/forums/showthread.php?p=5930338&highlight=Bernoulli+Kline+Fogleman#post5930338

    The Kline-Fogelman airfoil should not fly. The pronounced step on the underside creates a low pressure pocket UNDER the wing, totally contrary to Bernoulli's Theorum. Kline and Fogleman claim the low pressure zone under the wing actually propels the wing forward, but truthfully, I had serious doubts. After all, 100 years of aerodynamic theory can't be wrong.

    -Steve
     
  3. 3DMON

    3DMON Moderator Staff Member

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    This will be interesting. I hope you do try it out.
     
  4. 66tbird

    66tbird Moderator Staff Member

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    Ah! The old question! Which is it, Bernoulli's principle or angular deflection?

    The answer is both, though Bernoulli's principle only plays a small part. The reasoning has been already provided in the angle of incidence pictures of a typical Clark Y. In the 0 degree picture the incidence looks negative, and is from our modeling eyes. We always think a flat bottom at 0 degrees means the 'flat of the bottom' is 0 degrees. Which would let us think that the airfoil does all the work.

    Yet, as the picture shows, the incidence line goes through the airfoil at a higher point than the flat bottom line. So in the modeling world setting a flat bottom airfoil to 0 degrees in line with the stab is really a positive incidence. (flying on Angular Deflection)

    I've made a few airfoils for different applications over the years and I can tell you the leading edge makes the difference for angles in the 3 to 7 range. The bottom third plays a big part in the 5-15 degree range (flap area). And I've never found anything providing useful lift at a true 0 degree incidence.

    All up, the BigWheel will test glide if balanced and all but will not sustain forward flight in that configuration. May mow the lawn nice though :D
     
  5. blindflight

    blindflight Moderator Staff Member

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    I remember seeing some old film of "those crazy men in their flying machines", it was black & white.... :eek:
     
  6. 7up

    7up Moderator Staff Member

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    With enough power anything will fly. :D
     
  7. tvcasualty

    tvcasualty New Member

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    Lol I've seen that one blindflight! One of my favs growin up!
    I think tbird has correctly explained it, but let me add a bit more...

    Based on everything I've read and have seen, Bernoulli's Theorem means practically nothing, at least for RC.

    It all boils down to the properties of air-
    Air acts as a fluid, and just as if you are throwing something through your swimming pool, the fact is that as your object passes through the fluid; the fluid actually keeps whatever is moving from dropping abruptly, simply because the fluid can't be compressed in the small amount of time that it’s suspended by that particular particle of fluid... Whatever you are throwing eventually drops when it’s lost enough speed to allow the fluid to slip around it. (Things like balls will lose speed much faster then more slippery things like torpedoes…)

    But this all means practically anything will fly, as long as it’s moving.

    -OR MAYBE NOT…

    It’s not necessarily the speed of the object in the air, but the speed of the air around the object. And that’s the same reason things like houses and trees can fly in a wind storm (think of the force needed to pull such a thing from the ground).

    However I think that even if you get it in the air, good luck controlling your big wheel at slow speeds, it will simply lack any authority.

    I can’t wait to see the video either way, good luck!
     
  8. kram242

    kram242 Administrator Staff Member

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    Thank you everyone this is what I was hoping to hear a good argument from both sides.
    I have learned a lot just read these few post so far.

    Mark

    One of tha main reasons I would like this to work is for another design I have been working on called the Blower Plane
    Heres a pic and a video I think its a worlds first :)

    [​IMG]

    [​IMG]
    Attached files [​IMG] [​IMG]
     
  9. blindflight

    blindflight Moderator Staff Member

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    Found this:

    Attached files [​IMG]
     
  10. JBourdon

    JBourdon New Member

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  11. 66tbird

    66tbird Moderator Staff Member

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  12. kram242

    kram242 Administrator Staff Member

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    Thanks 66tbird,
    That company has come a long way! that thing looks cool in the air and it sounds like a jet :)
    Mark
     
  13. 66tbird

    66tbird Moderator Staff Member

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    Here is a newer vid of the plane in action. at 12 lbs and about 60'' it takes off quick. Easy to tell that tail boom is doing some work and that lift rotor is really doing its job. With a flying speed of 25-30 mph I'd hate to dead stick it, if it can.
    http://www.fanwing.com/
     
  14. kram242

    kram242 Administrator Staff Member

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    66tbird,
    thanks for sharing this
    That guys seems really nice from watching him on the video.
    It really is amazing that he can get 80 min flying time spinning all those rotors. They must have a huge battery pack in there and with the design it should have no problem lifting it.
    Mark
     
  15. JBourdon

    JBourdon New Member

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