prop shrouds

Discussion in 'Boat Design' started by waterwar, Jan 31, 2011.

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  1. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Waterwar: if you have an old OMC outboard and are talking about joining the big dogs in speeds, you must be delusional. The boat is a crapper too. You want speed, you need new technology and lots of money. I can sell it to you, but show the money first. BS is plentiful and free.
     
  2. Submarine Tom

    Submarine Tom Previous Member

    "Talk's cheap 'till you get the bill."

    -Tom
     
  3. waterwar

    waterwar Previous Member

    Thank you for the advice

    'Vows made in stormy waters are forgotten in calm ones.'

    I appreciate your sage advice I want to thank all who have given so much of their time to share knowledge on a very complex problem
    The advancements in the last fifty years in marine propulsion are impressive.
    I want to thank everyone for sharing here.
    Putting all those ideas on a subject such as you all have shown willingness to do..
    In particular, l I want to thank the various engineers who shared their knowledge on the complex subject freely.

    If you look at the old threads the subject was dismissed go to another beach

    we need to advance this application; to find one that does work reasonably well
    I mean no endorsement of any one product unless it works does the prop guard live up? what could be made different?

    thanks :)
    stewart
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    A propeller resistant manatee? :)
     
  5. waterwar

    waterwar Previous Member

    I have a little advice too about boat ownership its like a woman you can't wait to get until you do then you look forward to another..
     
  6. waterwar

    waterwar Previous Member

    I think there's room for them and you too gonzo personal differences aside
     
  7. Jeremy Harris
    Joined: Jun 2009
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    Jeremy Harris Senior Member

    You can't defy the laws of physics, I'm afraid. There's no way to remove the extra drag that the duct produces, and as the power needed to overcome drag is proportional to the cube of speed it only gets worse the faster you go.

    You can explore ways to improve on the efficiency of the best ducted props/pump jets around by careful design of duct and blade shape, but that still won't make them operate at high speed without high losses too.

    These things first came about on outboards as propguards, to protect people or marine life from being injured by exposed props. They do that job well and some marketeers have extolled the increased low speed thrust enhancement as a selling point. As has been said before, if you want more low speed thrust they work OK, if you want higher speed they don't. Technology isn't going to change this basic principle, much as you might want it to.

    Jeremy
     
  8. waterwar

    waterwar Previous Member

    I am a fish farmer and like to collect some times I use a trailer-able boat and its freshwater lakes and swamps here my friend not the deep briny deep
    jeez
     
  9. waterwar

    waterwar Previous Member

    thank you Jeremy'
    the maker of the 'prop guard has his dad for his nozzle contribution

    but i guess wishing it does work doesn't make it so

    thanks
    stew
     
  10. waterwar

    waterwar Previous Member

    When I was young we used to attach a pitchfork on an outboard and go up the rapids of the South fork of the shenandoah river in the Blue ridge mountains and fish for trout and shoot carp with arrows.
    Wasn't pretty and great loss of speed.

    so the claims made by Mr. shultz are false? just cause thinking of am going to put one on my ole crate and i will feedback I can pull a skier now guess we'll see..
     
  11. gonzo
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    gonzo Senior Member

    It is really hard to understand what you write. If you took more care with the grammar, it would help.
     
  12. waterwar

    waterwar Previous Member

    gonzo all kidding aside I am seeking the real experts
     
  13. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    In what?
     
  14. waterwar

    waterwar Previous Member


  15. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    You should have said that some pages earlier IMHO
     
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