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Aerospace Ornithopter Design Question

  1. Sep 6, 2011 #1
    I've been designing an ornithopter, or bird-machine, if you will, but this is intended to be a manned aerial vehicle.. No, actually- it's like a jetpack, but with lightweight wings using carbon fiber and an electric engine with lithium batteries.

    The question here is- what is the ideal method of ornithopter flight? And why, of course.

    So far, my design is radically different- for liftoff, that is. The actual flight is done exactly like a bird's, but liftoff is done differently, by sheer brute force directly downward flapping using specially-designed wings to maximize vertical thrust, which is used in place of traditional "lift".

    This may seem impossible to maintain balance within reasonable terms, but it has a special balancing system that doesn't require computer processing, rather it works entirely mechanically(don't ask) to alter the wing thrust vector in real-time, and does automatically, as no human could ever hope to do this themselves, obviously. But don't worry about this aspect of the design, for now I want to focus entirely on vertical takeoff idealization.

    I'd like to get into a big discussion over this. I've been doing lots of research, and I can't stop coming to the conclusion that my current method of liftoff is actually the best one by far, but that just sounds like complete nonsense when I think of it like that, so it makes me uneasy and wondering what I'm missing that makes the reality of it the complete opposite, probably..
     
  2. jcsd
  3. Sep 8, 2011 #2
    So...you have a system with a special mechanical balance, an electric motor, and batteries that will be able to sustain said motor for an entire safe flight? Then, your "specially designed wings" deliver enough vertical thrust to lift a (at least) 160lb person into sustained flight, and can then, somehow, change their shape to deliver horizontal thrust?

    My answer. No way can you have such a mechanical system that is powered only by flapping that will be able to lift a person off the ground and sustain even a hover. The wings would have to be so big that they would themselves inhibit you from lifting off, if they didn't break first.
     
  4. Sep 8, 2011 #3
    Well, I wanted to discuss the idea, not beat it to death immediately by just saying "No way." I've lost some of the respect I had for this forum.
     
  5. Sep 8, 2011 #4
    The ideas are nice, and I'm sure it would be an elegant looking contraption, but I just don't see how you would get a vertical takeoff with flapping wings. Think about geese, the things can't really take off without getting a running start because they are heavy birds. It's even worse for us because we are much heavier and are not entirely streamlined for flight.

    If you want to lift a human off the ground vertically you will need a source of constant >150lb lift. If your wings can do that, they are likely very large, and the upstroke would take a pretty long time, by which time you are back on the ground again. I didn't mean to sound rude (though I guess my sarcasm was a bit offensive) but I just don't see it. I'd be happy to be proved wrong, but the whole "wings on a human" thing has been tried before...

    If you are convinced you've got something, I'd go for a powered takeoff (running, or jumping off something, etc)
     
  6. Sep 8, 2011 #5
    My secret weapon in this is a new method for vertical lift whereby the upstroke is used for the creation of what I refer to as a "vortice ball moment", and then downstroking into this will yeild unbelievable vertical thrust.

    Carbon fiber rods are affordable and will keep the wings from breaking. Toy ornithopters even use these.

    I'd just like some discussion over the good and bad of various ornithopter designs to help me avoid any possible pitfalls in my own design, and anything related to vortices would be useful.
     
  7. Sep 19, 2011 #6
    In theory da vinci's design could work for wings but as stated above they would only work as far as once your airbourne to create the upthrust needed to lift a person the power would need to be huge how would the directional power work would it be in the traditional helicopter tilt style of some entirely new method ? .
     
  8. Nov 9, 2011 #7

    jgb

    User Avatar

    Just Google ornithopter canada for 2 flying designs from the University of Toronto.

    One is human powered and the other is small engine powered, and flew in 2006.

    The engine powered craft is now residing at the Downsview airport Air and Space Museum in Toronto, but not for much longer as the museum is being forced to move by the building owners. They want the land to build a 4 pad skating rink.

    These links should whet your interest....

    http://www.switched.com/2010/09/23/first-human-powered-ornithopter-flight-recorded-by-canadian/

    http://www.ornithopter.net/index_e.html

    jgb
     
  9. Dec 30, 2011 #8
    Could you share your design, leaving your secret stuff out? It is possible to take lift using flapping wings and some people had success in it. Search Airglow HPA, or youtube for Ornithopter HPA, you will find lots of videos/attempts.

    We can discuss more if you want.


    Take care and best luck.
     
  10. Sep 12, 2012 #9
    Think about about the extinct creatures that could fly. They were very heavy. Helicopters are sort of crude and they can take-off vertically. I bet it is very possible.
     
  11. Sep 13, 2012 #10
    The Canadians build a successfull man-powered ornothopter (as was mentioned above) Granted, it needed a little bit of help taking off and employed some ground effect:

    http://www.sott.net/articles/show/2...al-powered-ornithopter-takes-flight-in-Canada

    If you are interested in this type of hydrodynamics/aerodynamics I suggested you read this:
    http://darwin.wcupa.edu/~biology/fish/pubs/pdf/2006AnnalRevFluidMech.pdf [Broken]
     
    Last edited by a moderator: May 6, 2017
  12. Sep 14, 2012 #11

    jgb

    User Avatar

    This "vortice ball" effect is how moths and butterflies and most insects fly. And it works only because of the aerodynamic viscosity effect at very small scales. Stiff flat wings make that effect possible.

    Once you get above the size of a small hummingbird the effect vanishes. Then you need an aerodynamic curved wing flapping in a somewhat circular fashion to generate the lift.

    On the up and forward part of the stroke, the wing gets lift like any airplane today.

    On the down and rearward part of the stroke, the wing gets lift from the "drag" effect of "pushing" against the air, like an oar through the water.

    The power to weight ratios is a whole other ball of wax.

    (Aeronautics 101)
     
  13. Jan 18, 2013 #12
    XATZ, Just curious whether you got any progress on your design. Gamera Project by UMD student is recent success in vertical flight. Also as mentioned by some one, UTIAS Ornithopter project is pretty good example.
     
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