prop. drag calculations

Discussion in 'Props' started by itzik, Oct 18, 2011.

  1. itzik
    Joined: Oct 2011
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    Location: israel

    itzik New Member

    hi there,
    can any of you discribe the way of calcu. for prop.thrust prop.resis.i.e. the tourq the creating during the work and finally how to calc. the drag force to check if my vessel will be able to move!!!! thank you
    i need a little bit more than a "thomb rule" no need to "dive" into hight matemat. as integrals etc. using pounds.diameters.length. knots weigh. and so will be fine
     
  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Can you please skip the non-standard abreviations and repost?
     
  3. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    The cheapest reliable resource I know of, where you can get all the desired info, is Dave Gerr's book "Propeller Handbook". You can get it from Amazon.com for as little as $9.00 - a bargain price for the valuable info it contains.
    Cheers
     
  4. itzik
    Joined: Oct 2011
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    Location: israel

    itzik New Member

    hi gonzo', here is my repost
    1- i kooking for simple formulas to calcu the following:
    boat drag power as function of speed/ wet area/hull type/ cof.-with the approp. units
    2- also looking for such formulas to calcu. the thrust of propp. as function of rev/ dia./ pitch if need also in approp. units
    3-also looking how to calcu. the real tourq as a function of the water resistance duering the working- i know how to find the theoreticl tourq as function of givven h.p. and revs but duiering the revolutions in water the water creats an "opposite" tourq due to viscosity of the water
    4- how to find the metacenter point
    thanks for yours kindness
    itzik
     
  5. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    For #1
    Go to the library.
    Request a copy of The Speed and Power of Ships by D.W.Taylor
    For #2 and 3
    Go to the library.
    Request a copy of the Transactions of the Society of Naval Architects and Marine Engineers,#60,1952. The paper you want is H.W. Lerbs, Moderately loaded propellers with a finite numbers of blades and an arbitrary distribution of circulation.
    For #4
    See the following post
    http://www.boatdesign.net/forums/boat-building/calculation-gm-8852.html#post60405
     

  6. itzik
    Joined: Oct 2011
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    Location: israel

    itzik New Member

    hi jehardiman
    thank tou for yours incorigment
    itzik
     
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