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Feasibility of My Son's Science Project?

  1. Mar 12, 2009 #1
    I strongly suspect that this forum is absolute overkill for my question, and in fact, I would be just as happy to be referred to a more appropriate forum, since I was unable to locate one on my own.

    My son is in 8th grade and has decided to create an arch damn for his Science project. He is using a large tub sectioned off with a water-sealed piece of plexiglass. There will be approximately 4 gallons of water behind the 'dam' with a small ~1" piece of PVC protruding through (the plexiglass) to allow water to escape into the 'river' below.

    The plan, and here's the feasibility question, is to create a functional turbine from a small Radio Shack motor, the kind found in small remote control cars. Our thinking is to cut blades into a small circular piece of aluminum and attach it to the shaft of the motor with epoxy.

    The idea then would be to insert the blades into the water flow of the PVC pipe so that the resulting motion of the motor would generate enough electricity to power a small LED light.

    What do you think? Will it work?

    Last edited: Mar 12, 2009
  2. jcsd
  3. Mar 12, 2009 #2


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    Welcome to PF. :smile:

    It might work. I think you'll want to do some experimenting with the generator-and-LED part of things, before proceeding with making the tub-dam.

    You might instead consider using a small DC fan, as sold for use in computers, as the generator. Then you won't have to worry about building and attaching your own turbine blades.

    I have used such a fan to visibly light up an LED, by simply turning the blades by hand. You can experiment with water coming out of a sink faucet, to get a sense of whether the dam would generate sufficient current.

    You can get a fan and LED for under $20. That's not too much to invest to find out if the idea is workable.

    Good luck!
  4. Mar 12, 2009 #3
    You will want to have the discharge pipe as far below the surface of the upstream "lake" as possible to create as much pressure head as you can. This is what drives your turbine. Keep the discharge above the "river" side also, but just slightly so. The more head you can develop, the more velocity you can get through your turbine.
  5. Mar 13, 2009 #4
    I'm having trouble visualising what you mean for the turbine.

    Are you making it like a windmill or fan, where the flow is axial and the blades are at an angle?

    Have you considered a water wheel or impeller type, id suspect that was easier to make.
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