Propeller and power from human

Discussion in 'Boat Design' started by Heiakon, Mar 10, 2005.

  1. Heiakon
    Joined: Mar 2005
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    Location: Norway

    Heiakon New Member

    I'm working on a schoolproject. We are designing a human powered boat. We're supposed to use Wageningers B-series propellers. The problem is that the BP value I find (to use in the Bp-delta diagram) is to low for the diagram. Of course I can tune the RPM so the Bp value fits into the diagram. But I wonder if there can be any better solution. Anyone who can give me a suggestion?

    We tested power on a excercise bicycle, and we got 450 W out.. The boat shall be built for an competion. The boat shall go 200 m. So we count around 1 min time from start to goal.

    We hope to get a speed up to 9 knots. Someone told us that CRP propellers can give us better effect... Is this true??

    Hope anyone can give me something..

    Greetings from Norway
  2. CDBarry
    Joined: Nov 2002
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    CDBarry Senior Member

    Get a copy of Principles of Naval Architecture (the current 3 vol set - you need Vol 2) through SNAME, probably by interlibrary loan. It has the algorithm to develop Kt, Kq vs J directly for B-series props.

    A CPP prop probably won't help, since you are only interested in one speed point.
  3. Davor
    Joined: Jul 2004
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    Location: Dubrovnik, Croatia

    Davor Naval Arch.

    Wageningen B series propeller

    Send me some data of the boat:

    Lwl, Bwl, T, T-transom, Cb, LCB.

    Hull shape (V, U ) = ?

    P= 450 W,

    RPM= ?


    Distance of center of propeller to water line = ?

    Send me this data and I will let you know what can be done.



  4. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    First, the Wageningen B series propeller is a pretty poor prop for human propulsion as the blade area distribution is all wrong. If you have to, use a B2-20 or so, pitch it well up, lower the RPM (about 200 max) to reduce losses, maximize the diameter, and DO use counter-rotating because it will get you better initial performance (I assume the 200m is from a standing start) from the human power so the added complexity is worth it. See if you can "bend" the rules and use the base Wageningen series to develop a better prop that the "standard" ones.

    When designing a HPV prop it is important to remember that the torque curve of a human turning a crank is basically flat until you reach about 40-60 RPM and falls off rapidly to 0 at about 90-120 RPM. This is due to the energy expended in just moving the mass of the legs so get your propulsor into training now. Also make the prolulsor recumbent with a backboard and handgrips to allow him to overpush his weight. A gear shift is also helpful once the vessel is moving well to recover torque on the curve.

    Try or for more on human powered vessels

    Edited to add
    Last edited: Mar 15, 2005
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