Best Propulsion Device for 60 knots

Discussion in 'Powerboats' started by RANCHI OTTO, Jun 26, 2006.

  1. RANCHI OTTO
    Joined: Apr 2005
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    RANCHI OTTO Naval Architect

    The other possibility is to install waterjets : Kamewa or MJP.
    One of the problems is the turbulances in the waterduct at the shaft at 60 knots....

    I think that the opc (overall propulsive coeff.) is higher for piercing screws at this high speed.
    My ASD (arrow system design) hull shape reduces the long. trim and give additional lift in the after bottom of the boat.
    The waterjet, in order to help the water intake in the duct, needs a certain attack dynamic long. angle otherwise the turbulance effect is hughe with loss of efficiency of the impeller.
    On the other hand fins or spade rudders produce additional resistance...

    For the moment I think that the better choiche remains the surface drive...but which? This is the question...!
     
  2. yipster
    Joined: Oct 2002
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    yipster designer

    i dont know that but wonder how air piercing props would compare at 60 knts :D
    [​IMG]
     
  3. buckknekkid
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    buckknekkid Senior Member


    Youre right, Smoking is bad for you anyway. I visited to consult on exactly the same situation for some gentlemen in Bar. If I had the nerve I would post pictures.:cool:
     
  4. dougfrolich
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    dougfrolich Senior Member


  5. RANCHI OTTO
    Joined: Apr 2005
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    Location: TRIESTE (ITALY)

    RANCHI OTTO Naval Architect

    Thanks dougfrolich.
    The model S1500 is at the limit of the 1500 bhp to be installed.
    The other models are to heavy..anyway I've take contact with Flexytab..
     
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