Finding optimal propeller dimension based on ships speed and hull resistance

Discussion in 'Hydrodynamics and Aerodynamics' started by Simme_swede, Apr 2, 2024.

  1. baeckmo
    Joined: Jun 2009
    Posts: 1,743
    Likes: 755, Points: 113, Legacy Rep: 1165
    Location: Sweden

    baeckmo Hydrodynamics

    You have messed up the dimensions; always start with a conversion to SI units, shaft speed in the kt, kq and J coefficients is in revs/second!
    The speed of advance (va) is the hull speed thru' water, corrected for the influence of the wake. Unless the hull has a very weird shape aft, the wake factor ("w") is seldom outside the range 0,9>1.

    Who is the author of the report you refer to, and where is it published?

    Sorry about the pipeline; iirc in the late sixties the students organization held one (1) stock share in the brewery, which entiteled student representatives to attend to the stockholders' annual meetings and propose the building of said pipe...... You got to hang on there guys!!
     

  2. Simme_swede
    Joined: Apr 2024
    Posts: 5
    Likes: 0, Points: 1
    Location: Sweden

    Simme_swede Junior Member

    I owe you a beer baeckmo!

    How dumb of us to not check that all units are SI. Now our first model works quite well, it is not based on the literature you presented but that method would work as well I assume! We used a research paper by: Hamid Zeraatgar and Hossein Ghaemi, it was published by researchGate and here is the link:

    https://www.researchgate.net/public..._Interaction_Principles_and_Governor_Features

    Cool to hear!
    I think me and my friend have some leverage at åbro from when we tattooed a beer on our thighs :p I think it should be enough to get a year's worth of beer, at least!
    Thank you again for the help!
     
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