New Design Prop That Acts Like A Nozzle?

Discussion in 'Props' started by laurie dixon, Apr 11, 2014.

  1. laurie dixon
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    laurie dixon Junior Member

    I have designed a new type of propeller that as been tested on a lifeboat with a saab 12 hp diesel rated 1800 rpm into a 2to1 gear box the test was carried out in a closed dock.. the boats own prop was 16 inch x 3 blades the bollard pull running at full revs was 180 kilos and the revs was 874 rpm the pitch of his prop was 12 inch and book speed 6.5 knots.... i put my design onto the boat and carried out the same tests full speed bollard pull was 220 kilos and the speed was a lot faster the RPM was down to 849, but this prop as 13 inch of pitch on the blades the propeller turns without any cavitation and pushes the boat along with the bow right up i need help to do further testing on this i look forward to any input any member and point me in the right direction but i have done a lot of work on this and it does work but it needs help from someone
     
  2. daiquiri
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    daiquiri Engineering and Design

    And what sort of help do you need? Technical (engineering), legal (patenting), economic (investors), marketing, or...?
     
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    If you have really designed a propellor that clearly outperforms existing design, we need your help ! :D
     
  4. laurie dixon
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    laurie dixon Junior Member

    That is the problem as i have done just that but here now this needs to have more test and i have not got the funds to carry them out FOOTNOTE FOR EVERY INCH OF PITCH IS IS ABOUT 100 RPM by rule of thumb,
     
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    Does it resemble any existing propellor you know of ? Not a ring propellor ? Why did you not test the boat underway, rather than just in a dock ?
     
  6. laurie dixon
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    laurie dixon Junior Member

    Well the dock is called albert dock here in hull uk its over a mile long we did run the boat up and down that dock so there was no tide as the locks was closed, if we had gone into the river there is a 4 knot tide in the river humber but this design is not a ring propellor but i have called it the watertrap propellor blade. it nothing like any thing on the market today and it produces the same amount of thrust per HP has a kort nozzle would but as its part of the prop it works at all speeds unlike a nozzle at high speed does not work?
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    What "high speed" tests have you done ? Surely not with a 12 hp diesel ?
     
  8. laurie dixon
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    laurie dixon Junior Member

    THE book speed of this boat was 6.5 knots on test carried out with the boats own prop full speed was 6.4 knots 2 years ago on my test there said it was moving at well over 7 knots at 40 rpm down this is all on film and photos etc to show any company that would be willing to become economic investor to take this prop to companies like sunseeker etc, has it needs to be the same rpm to prove it now im only 40 revs away but there is 13 inch of pitch the boats own prop has 12 inch of pitch yes i will beat it from all the tests ..... iv done...
     
  9. Mr Efficiency
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    Mr Efficiency Senior Member

    You have a situation where you think you have something, but don't want to give away the "secret", this is understandable, what I think you need to demonstrate is that your propellor uses less fuel in driving a boat, that in the end would be the only criteria to apply.
     
  10. laurie dixon
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    laurie dixon Junior Member

    MR Efficiency your name says it all when i get the RPM up to the same as the boats propeller 874 rpm has it as a lot more thrust 20 percent and moves the boat faster we will have more Efficiency ie less fuel for more trust plus speed..
     
  11. Mr Efficiency
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    Mr Efficiency Senior Member

    Forget about the thrust, the speed of the boat at a given fuel consumption is all you need to know. Never mind the quality, feel the width !
     
  12. Mr Efficiency
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    Mr Efficiency Senior Member

    Bollard pull, also, is pretty well irrelevant unless you are towing something, you need to concentrate on fuel mileage.
     
  13. laurie dixon
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    laurie dixon Junior Member

    Like your quart, but this was designed for trust for trawlers in the beginning i know that it is producing more thrust and more speed all i need to do is get the RPM the same with both propellers and i will know how much more efficient this design is ?
     
  14. Mr Efficiency
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    Mr Efficiency Senior Member

    Your propellor may produce more thrust but have greater frictional losses, I can see where you are coming from with the trawlers because they are certainly towing. Maybe we can say, "performs an identical task but uses less fuel". If it does not, it is not going to cut it.
     

  15. laurie dixon
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    laurie dixon Junior Member

    When the RPM are both the same my design will give more thrust then the boats prop would be giving to the skipper, the revs would be reduced which will use less fuel with the watertrap blades but we shall see when I get some help to finish testing this idea etc etc.. i have done this test on a 3 inch model with an avo meter and a tachograph for the revs on the shaft /electric motor....
     
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