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Looking for project ideas

  1. Mar 29, 2010 #1
    Ok so here's the deal. Wind powered machine project..

    -Large Industrial Fan blowing
    -4 meters away from the fan is a wooden block on the ground with a hook in it (to attach rope, etc)
    -must pull the wooden block 4 meters TOWARDS the fan in the fastest amount of time possible
    -machine must only be powered by wind. no stored energy, potential energy, etc.
    -cannot lubricate the floor or put anything under the block
    -no combustibles/other dangerous thingies :)
    -to get an A, time must be 2 second or faster

    So basically need to pull the block 4 meters TOWARDS the fan in the fastest amount of time possible using only the wind power of the fan.

    I'm thinking I could always use the ol' windmill technique but I'd rather do something different. Any ideas?
    Last edited: Mar 30, 2010
  2. jcsd
  3. Mar 29, 2010 #2


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    The first thing you need to do is find a way to harness the wind energy as most efficiently as possible.

    How heavy is the block, and how large is the fan? Could you simply put a sail on the block?
  4. Mar 30, 2010 #3
    minger - are you trying to restart that 'sailing upwind' thread :wink:
  5. Mar 30, 2010 #4
    The fan is probably 5 feet in diameter. It's a big fan however the wind coming from it is not as powerful as you might think. The wind is more... broad if that makes sense.. The block I'd say is .5-.75 lbs

    And I don't really see the point of putting a sail on the block because yes, it'd be sailing upwind.
  6. Mar 31, 2010 #5
    -no combustibles/other dangerous thingies :)

    that shoots all my ideas to heck

    how about a thin strong thread that gets caught in the fan blade and yanks the block into the fan
    that always happens when its NOT supposed to...

  7. Mar 31, 2010 #6
    Haha, unfortunately against the rules. That was my first idea ;)
  8. Mar 31, 2010 #7
    I can't understand how something could move up the stream of wind. To me the challenge is how to increase the momentum of the air particles so by conservation the block will have to move in the other direction. but the real life effect of drag would always push it back.

    Perhaps you could somehow take advantage of fluid dynamics to speed up the air. I am thinking a tube with a large end toward the fan and a small end at the back. This way the air would be moving faster out of the small end. But the drag would definitely push it back even if any force was gained. Maybe a lot of lubrication in the tube?
  9. Mar 31, 2010 #8
    Hmm. Perhaps I didn't explain this well enough. I can make some kind of machine directly in front of the fan to harness the wind and to pull the rope + block towards the machine and fan.
  10. Apr 1, 2010 #9
    Oh yeah, I had the wrong idea. Well you could put some sort of pulley supported by two stabilized legs in front of the fan. the rope would have a parachute on one end and the block on the other. the fan will start and the parachute will be blown back. to increase time you could attach other parachutes at periodic lengths along the rope, so when they go across the pulley they deploy, so the force doesn't die out.
  11. Apr 1, 2010 #10
    This might be a good idea. How would I make the parachutes?
  12. Apr 1, 2010 #11
    Hmm. I think they would have to be very light so they deployed easily. Possibly you could make them out of grocery bags. It really depends on how powerful the fan is, i could just see some of the parachutes sitting there and not opening up at all.
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