How do propellers propell a boat.

Discussion in 'Props' started by tom kane, Mar 12, 2015.

  1. tom kane
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    tom kane Senior Member

    There are many theories about how a boat propellers propel a boat and how that happens. Who has got it right?
     
    Last edited: Mar 12, 2015
  2. upchurchmr
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    upchurchmr Senior Member

    You are trolling Tom.
    Spoiling for a good argument?
     
  3. tom kane
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    tom kane Senior Member

    This is a discussion forum are you afraid of learning something different?
    Do you not have your opinions on how a propeller really propels a boat or jut take for granted what some and accept traditional says? If you are not interested don`t let your imagination run away. What is wrong with sharing experiences.
     
  4. powerabout
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    powerabout Senior Member

    Tom
    I was at a well known prop designer builders in the usa the other day
    They were telling me about a world record holding prop they just scanned and all 3 blades different. Which i know is normal.
    I said i wonder if someone will ever work out how props work, which drew a great laugh from the lunch table.
    Cheers
    Ps they are like sails....
     
  5. tom kane
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    tom kane Senior Member

    How do propellers propel a boat

    I find propellers very interesting and most interesting is how some people think they work even very experienced race boat fans come up with all sorts of explanations.
    Try Google propeller blades with vortex generators to reduce blade tip losses.
    or high rake angle high speed boat propeller with low energy losses.
     
  6. powerabout
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    powerabout Senior Member

    props?

    When we talk racing props, they get better and better when the material has stayed the same over 50 years
    Surely that means the science is not exact?
    Its all art.
     
  7. Ike
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    Ike Senior Member

    props are screwy (sorry, I couldn't help myself)
     
  8. upchurchmr
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    upchurchmr Senior Member

    It was a joke - mostly.

    We will see if you get any actual "factual" responses. :rolleyes:

    You can tell me "I told you so" if anything comes up.
    But in fact, this is a "discussion forum" so this is my discussion.

     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    Water has inertia, the propellor applies a force to it, you get a reaction. Simples !
     
  10. powerabout
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    powerabout Senior Member

    Thats 2 reactions, the suction side and the pressure side?
     
  11. Mr Efficiency
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    Mr Efficiency Senior Member

    No such thing as suction in our universe, but there is pressure. Or lack of it.
     
  12. powerabout
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    powerabout Senior Member

    too true, just high and low pressures
     
  13. daiquiri
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    daiquiri Engineering and Design

    If you tell us which theories you are referring to, perhaps we could discuss them and see which ones are right.
     
  14. DCockey
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    DCockey Senior Member

    In engineering no model/theory agrees with reality exactly, but depending on the use some models/theories are more applicable than others.
     

  15. DCockey
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    DCockey Senior Member

    Or suction can be defined as pressure lower than ambient.
     
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