nozzle

Discussion in 'Props' started by valdez63, Mar 15, 2012.

  1. valdez63
    Joined: Mar 2012
    Posts: 1
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    Location: ireland

    valdez63 New Member

    i am a skipper of a trawler,and am looking at fittin a nozzle.what type is best,rice,kort.i have heard some designers have also made some good ones aswell,and what kinda savings could i expect?she is 21.5mx 4.2m x 12 with 705 hp @ max 1300.we usually run at 11oorpm
     
  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    For the nozzle to work, the propeller has to be fitted to it. Nozzles are part of a system and not just a bolt-on part.
     
  3. johneck
    Joined: Nov 2011
    Posts: 242
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    Location: New England

    johneck Senior Member

    It depends on your operating conditions. Nozzles will be most effective at low speeds and much less so at roughly 10 kts or greater. If you spend alot of time pulling nets at 3-4 knots, you may find savings of 20% to get the same pulling power. If you spend alot of time running at higher speeds to and from your fishing area, much less or maybe none.
    There are several standard types of nozzles available, having different points for which they are optimized. The Rice nozzle, which is an airfoil nozzle sold by many others as well, provides a shape which reduces drag at higher speeds, so it is potentially applicable to vessels that spend more time at higher speeds. A standard KA19A nozzle has a very simple shape to make construction easier, and works very well.
    All nozzles will reduce backing capability and may affect maneuvering compared to an open prop.
    In order to do any real comparision of your system, someone will need the current propeller details as well as your operating condition(s).
     
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