Parallell coupled fish tail boat propulsion

Discussion in 'Hybrid' started by kjellhoegseth, Apr 9, 2007.

  1. kerosene
    Joined: Jul 2006
    Posts: 1,041
    Likes: 60, Points: 48, Legacy Rep: 358
    Location: finland

    kerosene Senior Member

    what do you know of me to call me a monkey?

    the study you linked to states:
    "studies on dolphins have calculated their tail fins to operate with efficiencies in the 75% to 90% range and that the flexibility of the fin helps contribute to this "

    You claim that:
    "The speed and power obtainable is almost twice that of the best props."

    Care to clarify that? Double the speed? There are many boats that use props and are plenty fast. You think they would go double the speed? or that you can get double the speed with same power?

    I would like to remind you that a 70% efficient propeller is not rare for example. And if we talk about "the best of props" then I think for narrow parameters 85+% is possible. Your study states that props can be as bad as 40% efficient. That is a questionable point of comparison.

    So are you saying oscillating system will be 150+ % efficient...?

    I would really like real answers in your words instead of insults and name calling .


    As far as electric propulsion - I am ready to make the bet. My claim:
    no more than 5% of new recreational craft over 500lbs and/or capable of 6+ knots will be electrically powered by end 2017.
    Note how generous I am considering you claim
    "It will allow electric drives to completely replace combustion engines in a few short years."

    How about? The loser pays $300 for the charity of choice of the winner.

    I appreciate the link and will try to find the time to read it as so far nobody promoting the oscillating drive has been able to explain how it would produce better efficiency over a prop. But please drop the name calling.
  2. penguin78
    Joined: Jan 2010
    Posts: 14
    Likes: 1, Points: 3, Legacy Rep: 22
    Location: aus

    penguin78 Junior Member

    electric future


    My claim was an exaggeration.
    And name calling is childish.
    At high speed props become more efficient.
    At low speed they are in-efficient.
    Props can be very efficient at certain speeds it seems.

    Oscillating foils (fish tails) can be efficient at low speed and high speed.
    Big slow sweeps at low speed, fast oscillations at high speed.
    Perhaps it is like a prop that can change its pitch.

    Please don't bet against the future, an army of innovators, and a tidal wave of technology.

    Keep your petrol engine, in 2017 you will be able to sell it to a collector or a museum.

  3. frogger1225
    Joined: Aug 2014
    Posts: 78
    Likes: 1, Points: 8, Legacy Rep: 12
    Location: Pennsylvania

    frogger1225 Junior Member

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