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Propeller Cowlings

Discussion in 'Technical Discussion' started by JWY, Feb 12, 2013.

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  1. JWY, Feb 12, 2013
    #1
    JWY

    JWY Senior Member

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    I'm looking for feedback on yachts with prop cowlings, Kort nozzles, or similar. I know of two single engine 65' trawlers: one with with a Kort Nozzle, one with a Rice. Does anyone else have experience? Has anyone done this as a retrofit?

    Judy
  2. K1W1, Feb 12, 2013
    #2
    K1W1

    K1W1 Senior Member

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    Hi,

    The Bloemsa and Van Breeman yacht launched as Flying Eagle has these fitted.
  3. HTMO9, May 27, 2013
    #3
    HTMO9

    HTMO9 Senior Member

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    All sorts of things are being tested in order to safe fuel on big commercial ships. The newest development was the twisted fin. A method of predirecting the flow towards the prop. Now the Mewis duct, the twisted fin and the twisted rudder with Flap and Costa Bulb have been combined on one ship. The calculations call for an reduction in fuel consumption of about 8 to 9 % at given speed. Gentleman, in my business, that is a LOT. We are talking $$$$$$.

    1. Mewis Duct and rudder with Flattner Flap, 2. Twisted Fin, 3. Twisted Rudder with Costa Bulb.

    Attached Files:

  4. brian eiland, May 27, 2013
    #4
    brian eiland

    brian eiland Senior Member

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    That's interesting. Anymore such info?

    The original posting sited prop cowlings which I would assume to be 'cowlings over the prop' such as Kort and Kitchen Rudder types. In general these 'cowlings' decreased effiency at speed.
  5. HTMO9, May 27, 2013
    #5
    HTMO9

    HTMO9 Senior Member

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    Try this one (www.becker-marine-systems.com). This is a Hamburg based company, specializing in all sorts of maritime developments.